--- 1/draft-ietf-httpbis-header-compression-03.txt 2013-10-21 17:14:53.382676689 -0700 +++ 2/draft-ietf-httpbis-header-compression-04.txt 2013-10-21 17:14:53.494679581 -0700 @@ -1,408 +1,478 @@ HTTPbis Working Group R. Peon Internet-Draft Google, Inc Intended status: Informational H. Ruellan -Expires: February 28, 2014 Canon CRF - August 27, 2013 +Expires: April 24, 2014 Canon CRF + October 21, 2013 HPACK - Header Compression for HTTP/2.0 - draft-ietf-httpbis-header-compression-03 + draft-ietf-httpbis-header-compression-04 Abstract This document describes HPACK, a format adapted to efficiently - represent HTTP headers in the context of HTTP/2.0. + represent HTTP header fields in the context of HTTP/2.0. + +Editorial Note (To be removed by RFC Editor) + + Discussion of this draft takes place on the HTTPBIS working group + mailing list (ietf-http-wg@w3.org), which is archived at + . + + Working Group information and related documents can be found at + (Wiki) and + (source code and issues + tracker). + + The changes in this draft are summarized in Appendix A.1. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on February 28, 2014. + This Internet-Draft will expire on April 24, 2014. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents - 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 2.1. Outline . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 3. Header Encoding . . . . . . . . . . . . . . . . . . . . . . . 3 - 3.1. Encoding Concepts . . . . . . . . . . . . . . . . . . . . 3 - 3.1.1. Encoding Context . . . . . . . . . . . . . . . . . . . 4 - 3.1.2. Header Table . . . . . . . . . . . . . . . . . . . . . 4 - 3.1.3. Reference Set . . . . . . . . . . . . . . . . . . . . 5 - 3.1.4. Header set . . . . . . . . . . . . . . . . . . . . . . 6 - 3.1.5. Header Representation . . . . . . . . . . . . . . . . 6 - 3.1.6. Header Emission . . . . . . . . . . . . . . . . . . . 6 - 3.2. Header Set Processing . . . . . . . . . . . . . . . . . . 7 - 3.2.1. Header Representation Processing . . . . . . . . . . . 7 - 3.2.2. Reference Set Emission . . . . . . . . . . . . . . . . 7 - 3.2.3. Header Set Completion . . . . . . . . . . . . . . . . 8 - 3.2.4. Header Table Management . . . . . . . . . . . . . . . 8 - 4. Detailed Format . . . . . . . . . . . . . . . . . . . . . . . 8 - 4.1. Low-level representations . . . . . . . . . . . . . . . . 8 - 4.1.1. Integer representation . . . . . . . . . . . . . . . . 8 - 4.1.2. Header Name Representation . . . . . . . . . . . . . . 10 - 4.1.3. Header Value Representation . . . . . . . . . . . . . 11 - 4.2. Indexed Header Representation . . . . . . . . . . . . . . 11 - 4.3. Literal Header Representation . . . . . . . . . . . . . . 11 - 4.3.1. Literal Header without Indexing . . . . . . . . . . . 11 - 4.3.2. Literal Header with Incremental Indexing . . . . . . . 12 - 4.3.3. Literal Header with Substitution Indexing . . . . . . 13 - 5. Parameter Negotiation . . . . . . . . . . . . . . . . . . . . 15 - 6. Security Considerations . . . . . . . . . . . . . . . . . . . 15 - 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 - 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 - 8.1. Normative References . . . . . . . . . . . . . . . . . . . 16 - 8.2. Informative References . . . . . . . . . . . . . . . . . . 16 + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 2.1. Outline . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 3. Header Field Encoding . . . . . . . . . . . . . . . . . . . . 5 + 3.1. Encoding Concepts . . . . . . . . . . . . . . . . . . . . 5 + 3.1.1. Encoding Context . . . . . . . . . . . . . . . . . . . 5 + 3.1.2. Header Table . . . . . . . . . . . . . . . . . . . . . 6 + 3.1.3. Reference Set . . . . . . . . . . . . . . . . . . . . 6 + 3.1.4. Header Field Representation . . . . . . . . . . . . . 7 + 3.1.5. Header Field Emission . . . . . . . . . . . . . . . . 8 + 3.2. Header Block Decoding . . . . . . . . . . . . . . . . . . 8 + 3.2.1. Header Field Representation Processing . . . . . . . . 8 + 3.2.2. Reference Set Emission . . . . . . . . . . . . . . . . 9 + 3.2.3. Header Set Completion . . . . . . . . . . . . . . . . 9 + 3.3. Header Table Management . . . . . . . . . . . . . . . . . 9 + 3.3.1. Maximum Table Size . . . . . . . . . . . . . . . . . . 9 + 3.3.2. Entry Eviction When Header Table Size Changes . . . . 10 + 3.3.3. Entry Eviction when Adding New Entries . . . . . . . . 10 + 4. Detailed Format . . . . . . . . . . . . . . . . . . . . . . . 10 + 4.1. Low-level representations . . . . . . . . . . . . . . . . 10 + 4.1.1. Integer representation . . . . . . . . . . . . . . . . 11 + 4.1.2. String Literal Representation . . . . . . . . . . . . 13 + 4.2. Indexed Header Field Representation . . . . . . . . . . . 14 + 4.3. Literal Header Field Representation . . . . . . . . . . . 15 + 4.3.1. Literal Header Field without Indexing . . . . . . . . 15 + 4.3.2. Literal Header Field with Incremental Indexing . . . . 16 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 17 + 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 + 6.1. Normative References . . . . . . . . . . . . . . . . . . . 18 + 6.2. Informative References . . . . . . . . . . . . . . . . . . 18 Appendix A. Change Log (to be removed by RFC Editor before - publication . . . . . . . . . . . . . . . . . . . . . 17 - A.1. Since draft-ietf-httpbis-header-compression-01 . . . . . . 17 - A.2. Since draft-ietf-httpbis-header-compression-01 . . . . . . 17 - Appendix B. Initial Header Tables . . . . . . . . . . . . . . . . 18 - B.1. Requests . . . . . . . . . . . . . . . . . . . . . . . . . 18 - B.2. Responses . . . . . . . . . . . . . . . . . . . . . . . . 19 - Appendix C. Example . . . . . . . . . . . . . . . . . . . . . . . 20 - C.1. First header set . . . . . . . . . . . . . . . . . . . . . 20 - C.2. Second header set . . . . . . . . . . . . . . . . . . . . 22 + publication . . . . . . . . . . . . . . . . . . . . . 19 + A.1. Since draft-ietf-httpbis-header-compression-03 . . . . . . 19 + A.2. Since draft-ietf-httpbis-header-compression-02 . . . . . . 19 + A.3. Since draft-ietf-httpbis-header-compression-01 . . . . . . 19 + A.4. Since draft-ietf-httpbis-header-compression-01 . . . . . . 19 + Appendix B. Static Table . . . . . . . . . . . . . . . . . . . . 20 + Appendix C. Huffman Codes For Requests . . . . . . . . . . . . . 22 + Appendix D. Huffman Codes for Responses . . . . . . . . . . . . . 28 + Appendix E. Examples . . . . . . . . . . . . . . . . . . . . . . 33 + E.1. Request Decoding Example With Huffman . . . . . . . . . . 33 + E.2. Request Decoding Example Without Huffman . . . . . . . . . 38 + E.3. Response Decoding Example With Huffman . . . . . . . . . . 43 + E.4. Response Decoding Example Without Huffman . . . . . . . . 51 1. Introduction This document describes HPACK, a format adapted to efficiently - represent HTTP headers in the context of HTTP/2.0. + represent HTTP header fields in the context of HTTP/2.0 (see + [HTTP2]). 2. Overview - In HTTP/1.X, headers are sent without any form of compression. As - web pages have grown to include dozens to hundreds of requests, the - redundant headers in these requests now pose a problem of measurable - latency and unnecessary bandwidth. 1 [PERF1] 2 [PERF2] + In HTTP/1.X (see [HTTP-p1]), header fields are sent without any form + of compression. As web pages have grown to include dozens to + hundreds of requests, the redundant header fields in these requests + now pose a problem of measurable latency and unnecessary bandwidth + (see [PERF1] and [PERF2]). - SPDY [SPDY] initially addressed this redundancy by compressing - headers with Deflate, which proved very effective at eliminating the - redundant headers. However, that aproach exposed a security risk as - demonstrated by the CRIME [CRIME]. + SPDY [SPDY] initially addressed this redundancy by compressing header + fields with Deflate, which proved very effective at eliminating the + redundant header fields. However, that aproach exposed a security + risk as demonstrated by the CRIME [CRIME]. - In this document, we propose a new header compressor which eliminates - the redundant headers, is not vulnerable to the CRIME style attack, - and which also has a bounded memory cost for use in small constrained - environments. + In this document, we propose a new compressor for header fields which + eliminates redundant header fields, is not vulnerable to CRIME style + attacks, and which also has a bounded memory cost for use in + constrained environments. 2.1. Outline - The HTTP header encoding described in this document is based on a - header table that map (name, value) pairs to index values. Header + The HTTP header field encoding described in this document is based on + a header table that map (name, value) pairs to index values. Header tables are incrementally updated during the HTTP/2.0 session. - The encoder is responsible for deciding which headers to insert as - new entries in the header table. The decoder then does exactly what - the encoder prescribes, ending in a state that exactly matches the - encoder's state. This enables decoders to remain simple and + The encoder is responsible for deciding which header fields to insert + as new entries in the header table. The decoder then does exactly + what the encoder prescribes, ending in a state that exactly matches + the encoder's state. This enables decoders to remain simple and understand a wide variety of encoders. - As two consecutive sets of headers often have headers in common, each - set of headers is coded as a difference from the previous set of - headers. The goal is to only encode the changes (headers present in - one of the set and not in the other) between the two sets of headers. + As two consecutive sets of header fields often have header fields in + common, each set of header fields is coded as a difference from the + previous set of header fields. The goal is to only encode the + changes (header fields present in one of the set and not in the + other) between the two sets of header fields. - An example illustrating the use of these different mechanisms to - represent headers is available in Appendix C. + Examples illustrating the use of these different mechanisms to + represent header fields are available in Appendix E. -3. Header Encoding +3. Header Field Encoding 3.1. Encoding Concepts - The encoding and decoding of headers relies on some components and - concepts. The set of components used form an encoding context. + The encoding and decoding of header fields relies on some components + and concepts: + + Header Field: A key, value pair. HPACK allows a header field value + to be either a value as specified by HTTP/1.X (see [HTTP-p1]), or + a NULL-separated ordered list of HTTP/1.X values. Header Table: The header table (see Section 3.1.2) is a component - used to associate headers to index values. + used to associate stored header fields to index values. The data + stored in this table is in first-in, first-out order. + + Static Table: The static table (see Appendix B) is a component used + to associate static header fields to index values. This data is + ordered, read-only, always accessible, and may be shared amongst + all encoding contexts. Reference Set: The reference set (see Section 3.1.3) is a component - containing a group of headers used as a reference for the - differential encoding of a new set of headers. + containing an unordered set of references to entries in the header + table or static table. This is used for the differential encoding + of a new header set. - Header Set: A header set (see Section 3.1.4) is a group of headers - that are encoded jointly. A complete set of key-value pairs as - encoded in an HTTP request or response is a header set. + Header Set: A header set is a potentially ordered group of header + fields that are encoded jointly. A complete set of key-value + pairs contained in a HTTP request or response is a header set. - Header Representation: A header can be represented in encoded form - either as a literal or as an index (see Section 3.1.5). The - indexed representation is based on the header table. + Header Field Representation: A header field can be represented in + encoded form either as a literal or as an index (see + Section 3.1.4). - Header Emission: When decoding a set of headers, some operations - emit a header (see Section 3.1.6). An emitted header is added to - the set of headers that form the HTTP request or response. Once - emitted, a header can't be removed from the set of headers. + Header Block: The entire set of encoded header field representations + which, when decoded, yield a complete header set. + + Header Field Emission: When decoding a set of header field + representations, some operations emit a header field (see + Section 3.1.5). Emitted headers can be safely passed to the upper + processing layers as part of the current Header Set. 3.1.1. Encoding Context - The set of components used to encode or decode a header set form an - encoding context: an encoding context contains a header table and a - reference set. + The set of mutable structures used within an encoding context include + a header table and a reference set. Everything else is either + immutable or conceptual. Using HTTP, messages are exchanged between a client and a server in - both direction. To keep the encoding of headers in each direction - independent from the other direction, there is one encoding context - for each direction. + both direction. To keep the encoding of header fields in each + direction independent from the other direction, there is one encoding + context for each direction. - The headers contained in a PUSH_PROMISE frame sent by a server to a - client are encoded within the same context as the headers contained - in the HEADERS frame corresponding to a response sent from the server - to the client. + The header fields contained in a PUSH_PROMISE frame sent by a server + to a client are encoded within the same context as the header fields + contained in the HEADERS frame corresponding to a response sent from + the server to the client. 3.1.2. Header Table - A header table consists of an ordered list of (name, value) pairs. - The first entry of a header table is assigned the index 0. - - A header can be represented by an entry from the header table. - Rather than encoding a literal value for the header field name and - value, the encoder can select an entry from the header table. - - Literal header names MUST be translated to lowercase before encoding - and transmission. This enables an encoder to perform direct bitwise - comparisons on names and values when determining if an entry already - exists in the header table. - - There is no need for the header table to contain duplicate entries. - However, duplicate entries MUST NOT be treated as an error by a - decoder. + A header table consists of a list of header fields maintained in + first-in, first-out order. The first and newest entry in a header + table is always at index 0, and the oldest entry of a header table is + at the index len(header table)-1. - Initially, a header table contains a list of common headers. Two - initial lists of header are provided in Appendix B. One list is for - headers transmitted from a client to a server, the other for the - reverse direction. + The header table is initially empty. - A header table is modified by either adding a new entry at the end of - the table, or by replacing an existing entry. + There is typically no need for the header table to contain duplicate + entries. However, duplicate entries MUST NOT be treated as an error + by a decoder. The encoder decides how to update the header table and as such can control how much memory is used by the header table. To limit the memory requirements on the decoder side, the header table size is - bounded (see the SETTINGS_HEADER_TABLE_SIZE in Section 5). - - The size of an entry is the sum of its name's length in bytes (as - defined in Section 4.1.2), of its value's length in bytes - (Section 4.1.3) and of 32 bytes. The 32 bytes are an accounting for - the entry structure overhead. For example, an entry structure using - two 64-bits pointers to reference the name and the value and the - entry, and two 64-bits integer for counting the number of references - to these name and value would use 32 bytes. + strictly bounded (see Section 3.3.1). - The size of a header table is the sum of the size of its entries. + The header table is updated during the processing of a set of header + field representations (see header field representation processing + (Section 3.2.1). 3.1.3. Reference Set - A reference set is defined as an unordered set of references to - entries of the header table. + A reference set is an unordered set of references to entries either + within the header table or the static table. - The initial reference set is the empty set. + The reference set is initially empty. - The reference set is updated during the processing of a set of - headers. + The reference set is updated during the processing of a set of header + field representations (see header field representation processing + (Section 3.2.1). - Using the differential encoding, a header that is not present in the - reference set can be encoded either with an indexed representation - (if the header is present in the header table), or with a literal - representation (if the header is not present in the header table). + The reference set enables differential encoding, whereby only + differences between the previous header set and the current header + set need to be encoded. - A header that is to be removed from the reference set is encoded with - an indexed representation. + When an entry is evicted from the header table, if it was referenced + from the reference set, its reference is removed from the reference + set. -3.1.4. Header set +3.1.4. Header Field Representation - A header set is a group of header fields that are encoded as a whole. - Each header field is a (name, value) pair. + An encoded header field can be represented either as a literal or as + an index. - A header set is encoded using an ordered list of zero or more header - representations. All the header representations describing a header - set a grouped into a header block. + Literal Representation: A literal representation defines a new + header field. The header field name is represented either + literally or as a reference to an entry of the header table. The + header field value is represented literally. -3.1.5. Header Representation + Two different literal representations are provided: - A header can be represented either as a literal or as an index. + * A literal representation that does not add the header field to + the header table (see Section 4.3.1). - Literal Representation: A literal representation defines a new - header. The header name is represented either literally or as a - reference to an entry of the header table. The header value is - represented literally. + * A literal representation that adds the header field as a new + entry at the beginning of the header table (see Section 4.3.2). - Three different literal representations are provided: + Indexed Representation: The indexed representation defines a header + field as a reference to an entry in either the header table or the + static table(see Section 4.2). - * A literal representation that does not add the header to the - header table (see Section 4.3.1). + <---------- Index Address Space ----------> + <-- Header Table --> <-- Static Table --> + +---+-----------+---+ +---+-----------+---+ + | 0 | ... | k | |k+1| ... | n | + +---+-----------+---+ +---+-----------+---+ + ^ | + | V + Insertion Point Drop Point - * A literal representation that adds the header at the end of the - header table (see Section 4.3.2). + Index Address Space - * A literal representation that uses the header to replace an - existing entry of the header table (see Section 4.3.3). + Indices between 0 and len(header table)-1, inclusive, refer to + elements in the header table, with index 0 referring to the + beginning of the table. - Indexed Representation: The indexed representation defines a header - as a reference in the header table (see Section 4.2). + Indices between len(header table) and len(header table)+ + len(static table)-1, inclusive, refer to elements in the static + table, where the index len(header table) refers to the first + entry in the static table. -3.1.6. Header Emission + Any other indices MUST be treated as erroneous, and the + compression context considered corrupt and unusable. - The emission of header is the process of adding a header to the - current set of headers. Once an header is emitted, it can't be - removed from the current set of headers. +3.1.5. Header Field Emission - The concept of header emission allows a decoder to know when it can - pass a header safely to a higher level on the receiver side. This - allows a decoder to be implemented in a streaming way, and as such to - only keep in memory the header table and the reference set. With - such an implementation, the amount of memory used by the decoder is - bounded, even in presence of a very large set of headers. The - management of memory for handling very large sets of headers can - therefore be deferred to the application, which may be able to emit - the header to the wire and thus free up memory quickly. + The emission of a header field is the process of passing that header + field to the application, so that the application can process and + react to header field data. -3.2. Header Set Processing + By emitting header fields instead of emitting header sets, the + decoder can be implemented in a streaming way, and as such must only + keep in memory the header table and the reference set. This bounds + the amount of memory used by the decoder, even in presence of a very + large set of header fields. The management of memory for handling + very large sets of header fields can therefore be deferred to the + application. - The processing of an encoded header set to obtain a list of headers - is defined in this section. To ensure a correct decoding of a header - set, a decoder MUST obey the following rules. + When a header field is a NULL-separated list of values, each value + within the list MAY be emitted separately, with the same header field + name, and the order of emission MUST be the order of appearance in + the list. -3.2.1. Header Representation Processing +3.2. Header Block Decoding - All the header representations contained in a header block are + The processing of a header block to obtain a header set is defined in + this section. To ensure that the decoding will successfully produce + a header set, a decoder MUST obey the following rules. + +3.2.1. Header Field Representation Processing + + All the header field representations contained in a header block are processed in the order in which they are presented, as specified below. + An _indexed representation_ corresponding to an entry _present_ in + the reference set entails the following actions: + + o The reference to the entry is removed from the reference set. + An _indexed representation_ corresponding to an entry _not present_ in the reference set entails the following actions: - o The header corresponding to the entry is emitted. + o If referencing an element of the static table: - o The entry is added to the reference set. + * The header field corresponding to the referenced entry is + emitted. - An _indexed representation_ corresponding to an entry _present_ in - the reference set entails the following actions: + * The referenced static entry is added to the header table. - o The entry is removed from the reference set. + * If the new entry fits within the header table, a reference to + the header table entry is added to the reference set. + + o If referencing an element of the header table: + + * The header field corresponding to the referenced entry is + emitted. + + * The referenced header table entry is added to the header table. A _literal representation_ that is _not added_ to the header table entails the following action: - o The header is emitted. + o The header field is emitted. A _literal representation_ that is _added_ to the header table entails the following actions: - o The header is emitted. + o The header field is inserted at the beginning of the header table. - o The header is added to the header table, at the location defined - by the representation. + o A reference to the new entry is added to the reference set. - o The new entry is added to the reference set. + o The header field is emitted. 3.2.2. Reference Set Emission Once all the representations contained in a header block have been - processed, the headers that are in common with the previous header - set are emitted, during the reference set emission. - - For the reference set emission, each header contained in the - reference set that has not been emitted during the processing of the - header block is emitted. + processed, the header fields referenced in the reference set which + have not previously been emitted during this processing are emitted. 3.2.3. Header Set Completion - Once all of the header representations have been processed, and the - remaining items in the reference set have been emitted, the header - set is complete. + Once all of the header field representations have been processed, and + the remaining items in the reference set have been emitted, the + header set is complete. -3.2.4. Header Table Management +3.3. Header Table Management - The header table can be modified by either adding a new entry to it - or by replacing an existing one. Before doing such a modification, - it has to be ensured that the header table size will stay lower than - or equal to the SETTINGS_HEADER_TABLE_SIZE limit (see Section 5). To - achieve this, repeatedly, the first entry of the header table is - removed, until enough space is available for the modification. +3.3.1. Maximum Table Size - A consequence of removing one or more entries at the beginning of the - header table is that the remaining entries are renumbered. The first - entry of the header table is always associated to the index 0. + To limit the memory requirements on the decoder side, the size of the + the header table is bounded. The size of the header table MUST stay + lower than or equal to the value of the HTTP/2.0 setting + SETTINGS_HEADER_TABLE_SIZE (see [HTTP2]). - When the modification of the header table is the replacement of an - existing entry, the replaced entry is the one indicated in the - literal representation before any entry is removed from the header - table. If the entry to be replaced is removed from the header table - when performing the size adjustment, the replacement entry is - inserted at the beginning of the header table. + The size of the the header table is the sum of the size of its + entries. - The addition of a new entry with a size greater than the - SETTINGS_HEADER_TABLE_SIZE limit causes all the entries from the - header table to be dropped and the new entry not to be added to the - header table. The replacement of an existing entry with a new entry - with a size greater than the SETTINGS_HEADER_TABLE_SIZE has the same - consequences. + The size of an entry is the sum of its name's length in bytes (as + defined in Section 4.1.2), of its value's length in bytes + (Section 4.1.2) and of 32 bytes. + + The lengths are measured on the non-encoded entry name and entry + value (for the case when a Huffman encoding is used to transmit + string values). + + The 32 bytes are an accounting for the entry structure overhead. For + example, an entry structure using two 64-bits pointers to reference + the name and the value and the entry, and two 64-bits integer for + counting the number of references to these name and value would use + 32 bytes. + +3.3.2. Entry Eviction When Header Table Size Changes + + Whenever an entry is evicted from the header table, any reference to + that entry contained by the reference set is removed. + + Whenever SETTINGS_HEADER_TABLE_SIZE is made smaller, entries are + evicted from the end of the header table until the size of the header + table is less than or equal to SETTINGS_HEADER_TABLE_SIZE. + + The eviction of an entry from the header table causes the index of + the entries in the static table to be reduced by one. + +3.3.3. Entry Eviction when Adding New Entries + + Whenever a new entry is to be added to the table, any name referenced + by the representation is cached, and then entries are evicted from + the end of the header table until the size of the header table is + less than or equal to SETTINGS_HEADER_TABLE_SIZE - new entry size, or + until the table is empty. + + If the size of the new entry is less than or equal to + SETTINGS_HEADER_TABLE_SIZE, that entry is added to the table. It is + not an error to attempt to add an entry that is larger than + SETTINGS_HEADER_TABLE_SIZE. 4. Detailed Format 4.1. Low-level representations - 4.1.1. Integer representation Integers are used to represent name indexes, pair indexes or string lengths. To allow for optimized processing, an integer representation always finishes at the end of a byte. An integer is represented in two parts: a prefix that fills the current byte and an optional list of bytes that are used if the - integer value does not fit in the prefix. The number of bits of the - prefix (called N) is a parameter of the integer representation. + integer value does not fit within the prefix. The number of bits of + the prefix (called N) is a parameter of the integer representation. The N-bit prefix allows filling the current byte. If the value is small enough (strictly less than 2^N-1), it is encoded within the N-bit prefix. Otherwise all the bits of the prefix are set to 1 and the value is encoded using an unsigned variable length integer [1] - representation. + representation. N is always between 1 and 8 bits. An integer + starting at a byte-boundary will have an 8-bit prefix. The algorithm to represent an integer I is as follows: If I < 2^N - 1, encode I on N bits Else encode 2^N - 1 on N bits I = I - (2^N - 1) While I >= 128 Encode (I % 128 + 128) on 8 bits I = I / 128 encode (I) on 8 bits + This integer representation allows for values of indefinite size. It + is also possible for an encoder to send a large number of zero + values, which can waste bytes and could be used to overflow integer + values. Excessively large integer encodings - in value or octet + length - MUST be treated as a decoding error. Different limits can + be set for each of the different uses of integers, based on + implementation constraints. + 4.1.1.1. Example 1: Encoding 10 using a 5-bit prefix The value 10 is to be encoded with a 5-bit prefix. o 10 is less than 31 (= 2^5 - 1) and is represented using the 5-bit prefix. 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ | X | X | X | 0 | 1 | 0 | 1 | 0 | 10 stored on 5 bits @@ -436,328 +506,321 @@ The process ends. 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ | X | X | X | 1 | 1 | 1 | 1 | 1 | Prefix = 31, I = 1306 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 1306>=128, encode(154), I = 1306/128 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 10<128, encode(10), done +---+---+---+---+---+---+---+---+ -4.1.2. Header Name Representation - - Header names are sequences of ASCII characters that MUST conform to - the following header-name ABNF construction: +4.1.2. String Literal Representation - LOWERALPHA = %x61-7A - header-char = "!" / "#" / "$" / "%" / "&" / "'" / - "*" / "+" / "-" / "." / "^" / "_" / - "`" / "|" / "~" / DIGIT / LOWERALPHA - header-name = [":"] 1*header-char + Header field names and header field values are encoded as sequences + of bytes. A header field name or a header field value is encoded in + three parts: - They are encoded in two parts: + 1. One bit, H, indicating whether or not the bytes are huffman + encoded. - 1. The length of the text, defined as the number of octets of - storage required to store the text, represented as a variable- - length-quantity (Section 4.1.1). + 2. The number of bytes required to hold the result of the next step, + represented as a variable-length-quantity (Section 4.1.1), + starting with a 7-bit prefix immediately following the first bit. - 2. The specific sequence of ASCII octets + 3. The encoded data of the string: -4.1.3. Header Value Representation + 1. If H is true, then the the encoded string data is the bitwise + concatenation of the canonical [CANON]huffman code [HUFF] + corresponding to each character of the data, followed by + between 0-7 bits of padding. - Header values are encoded as sequences of UTF-8 encoded text. They - are encoded in two parts: + 2. If H is false, then the encoded string is the bytes of the + field value without modification. - 1. The length of the text, defined as the number of octets of - storage required to store the text, represented as a variable- - length-quantity (Section 4.1.1). + Padding is necessary when doing huffman encoding to ensure that the + remaining bits between the actual end of the data and the next byte + boundary are not misinterpreted as part of the input data. - 2. The specific sequence of octets representing the UTF-8 text. + When padding for huffman encoding, use the bits from the EOS (end-of- + string) entry in the Huffman table, starting with the MSB. This + entry is guaranteed to be at least 8 bits long. - Invalid UTF-8 octet sequences, "over-long" UTF-8 encodings, and UTF-8 - octets that represent invalid Unicode Codepoints MUST NOT be used. + String literals sent in the client to server direction which use + huffman encoding are encoded with the codes within the request + huffman code table (Appendix C) (see Request Decoding With Huffman + Example (Appendix E.3)). -4.2. Indexed Header Representation + String literals sent in the server to client direction which use + huffman encoding are encoded with the codes within the response + huffman code table (Appendix D) (see Response Decoding With Huffman + Example (Appendix E.3)). - An indexed header representation identifies an entry in the header - table. The entry is emitted and added to the reference set if it is - not currently in the reference set. The entry is removed from the - reference set if it is present in the reference set. + The EOS symbol is represented with value 256, and is used solely to + signal the end of the huffman-encoded key data or the end of the + huffman-encoded value data. Given that only between 0-7 bits of the + EOS symbol is included in any huffman-encoded string, and given that + the EOS symbol is at least 8 bits long, it is expected that it should + never be successfully decoded. 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ - | 1 | Index (7+) | - +---+---------------------------+ - - Indexed Header - - This representation starts with the '1' 1-bit pattern, followed by - the index of the matching pair, represented as an integer with a - 7-bit prefix. - -4.3. Literal Header Representation - - Literal header representations contain a literal header field value. - Header field names are either provided as a literal or by reference - to an existing header table entry. - - Literal representations all result in the emission of a header when - decoded. - -4.3.1. Literal Header without Indexing + | 1 | Value Length Prefix (7) | + +---+---+---+---+---+---+---+---+ + | Value Length (0-N bytes) | + +---+---+---+---+---+---+---+---+ + ... + +---+---+---+---+---+---+---+---+ + | Huffman Encoded Data |Padding| + +---+---+---+---+---+---+---+---+ - An literal header without indexing causes the emission of a header - without altering the header table. + String Literal With Huffman Encoding 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ - | 0 | 1 | 1 | Index (5+) | - +---+---+---+-------------------+ - | Value Length (8+) | - +-------------------------------+ - | Value String (Length octets) | - +-------------------------------+ + | 0 | Value Length Prefix (7) | + +---+---+---+---+---+---+---+---+ + | Value Length (0-N bytes) | + +---+---+---+---+---+---+---+---+ + ... + +---+---+---+---+---+---+---+---+ + | Field Bytes Without Encoding | + +---+---+---+---+---+---+---+---+ - Literal Header without Indexing - Indexed Name + String Literal Without Huffman Encoding + +4.2. Indexed Header Field Representation + + An indexed header field representation either identifies an entry in + the header table or static table. The specified entry is emitted and + a reference to that entry is added to the reference set if it is not + currently in the reference set. If it is present in the reference + set then the reference is removed and the entry is not emitted. 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ - | 0 | 1 | 1 | 0 | - +---+---+---+-------------------+ - | Name Length (8+) | - +-------------------------------+ - | Name String (Length octets) | - +-------------------------------+ - | Value Length (8+) | - +-------------------------------+ - | Value String (Length octets) | - +-------------------------------+ + | 1 | Index (7+) | + +---+---------------------------+ - Literal Header without Indexing - New Name + Indexed Header Field - This representation starts with the '011' 3-bit pattern. + This representation starts with the '1' 1-bit pattern, followed by + the index of the matching pair, represented as an integer with a + 7-bit prefix. - If the header name matches the header name of a (name, value) pair - stored in the Header Table, the index of the pair increased by one - (index + 1) is represented as an integer with a 5-bit prefix. Note - that if the index is strictly below 31, one byte is used. +4.3. Literal Header Field Representation - If the header name does not match a header name entry, the value 0 is - represented on 5 bits followed by the header name (Section 4.1.2). + Literal header field representations contain a literal header field + value. Header field names are either provided as a literal or by + reference to an existing header table or static table entry. - Header name representation is followed by the header value - represented as a literal string as described in Section 4.1.3. + Literal representations all result in the emission of a header field + when decoded. -4.3.2. Literal Header with Incremental Indexing +4.3.1. Literal Header Field without Indexing - A literal header with incremental indexing adds a new entry to the - header table. + A literal header field without indexing causes the emission of a + header field without altering the header table. 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ - | 0 | 1 | 0 | Index (5+) | + | 0 | 1 | Index (6+) | +---+---+---+-------------------+ | Value Length (8+) | +-------------------------------+ | Value String (Length octets) | +-------------------------------+ - Literal Header with Incremental Indexing - - Indexed Name + Literal Header Field without Indexing - Indexed Name 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ - | 0 | 1 | 0 | 0 | + | 0 | 1 | 0 | +---+---+---+-------------------+ | Name Length (8+) | +-------------------------------+ | Name String (Length octets) | +-------------------------------+ | Value Length (8+) | +-------------------------------+ | Value String (Length octets) | +-------------------------------+ - Literal Header with Incremental Indexing - - New Name + Literal Header Field without Indexing - New Name - This representation starts with the '010' 3-bit pattern. + This representation starts with the '01' 2-bit pattern. - If the header name matches the header name of a (name, value) pair - stored in the Header Table, the index of the pair increased by one - (index + 1) is represented as an integer with a 5-bit prefix. Note - that if the index is strictly below 31, one byte is used. + If the header field name matches the header field name of a (name, + value) pair stored in the Header Table or Static Table, the index of + that entry, increased by one (index + 1), is represented as an + integer with a 6-bit prefix. Note that if the index is strictly + below 63, only one byte is used for this representation. - If the header name does not match a header name entry, the value 0 is - represented on 5 bits followed by the header name (Section 4.1.2). + If the header field name does not match a header field name entry, + the value 0 is represented on 6 bits followed by the header field + name (Section 4.1.2). - Header name representation is followed by the header value - represented as a literal string as described in Section 4.1.3. + The header field name representation is followed by the header field + value represented as a literal string as described in Section 4.1.2. -4.3.3. Literal Header with Substitution Indexing +4.3.2. Literal Header Field with Incremental Indexing - A literal header with substitution indexing replaces an existing - header table entry. + A literal header field with incremental indexing adds a new entry to + the header table. 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ | 0 | 0 | Index (6+) | - +---+---+-----------------------+ - | Substituted Index (8+) | - +-------------------------------+ + +---+---+---+-------------------+ | Value Length (8+) | +-------------------------------+ | Value String (Length octets) | +-------------------------------+ - Literal Header with Substitution Indexing - + Literal Header Field with Incremental Indexing - Indexed Name 0 1 2 3 4 5 6 7 +---+---+---+---+---+---+---+---+ | 0 | 0 | 0 | - +---+---+-----------------------+ + +---+---+---+-------------------+ | Name Length (8+) | +-------------------------------+ | Name String (Length octets) | +-------------------------------+ - | Substituted Index (8+) | - +-------------------------------+ | Value Length (8+) | +-------------------------------+ | Value String (Length octets) | +-------------------------------+ - Literal Header with Substitution Indexing - + Literal Header Field with Incremental Indexing - New Name This representation starts with the '00' 2-bit pattern. - If the header name matches the header name of a (name, value) pair - stored in the Header Table, the index of the pair increased by one - (index + 1) is represented as an integer with a 6-bit prefix. Note - that if the index is strictly below 63, one byte is used. - - If the header name does not match a header name entry, the value 0 is - represented on 6 bits followed by the header name (Section 4.1.2). - - The index of the substituted (name, value) pair is inserted after the - header name representation as a 0-bit prefix integer. - - The index of the substituted pair MUST correspond to a position in - the header table containing a non-void entry. An index for the - substituted pair that corresponds to empty position in the header - table MUST be treated as an error. - - This index is followed by the header value represented as a literal - string as described in Section 4.1.3. - -5. Parameter Negotiation + If the header field name matches the header field name of a (name, + value) pair stored in the header table or static table, the index of + the pair increased by one (index + 1) is represented as an integer + with a 6-bit prefix. - A few parameters can be used to accommodate client and server - processing and memory requirements. [[anchor3: These settings are - currently not supported as they have not been integrated in the main - specification. Therefore, the maximum buffer size for the header - table is fixed at 4096 bytes.]] + If the header field name does not match a header field name entry, + the value 0 is represented on 6 bits followed by the header field + name (Section 4.1.2). - SETTINGS_HEADER_TABLE_SIZE (TBD): Allows the sender to inform the - remote endpoint of the maximum size it accepts for the header - table. - The default value is 4096 bytes. - [[anchor4: Is this default value OK? Do we need a maximum size? - Do we want to allow infinite buffer?]] - When the remote endpoint receives a SETTINGS frame containing a - SETTINGS_HEADER_TABLE_SIZE setting with a value smaller than the - one currently in use, it MUST send as soon as possible a HEADER - frame with a stream identifier of 0x0 containing a value smaller - than or equal to the received setting value. - [[anchor5: This changes slightly the behaviour of the HEADERS - frame, which should be updated as follows:]] - A HEADER frame with a stream identifier of 0x0 indicates that the - sender has reduced the maximum size of the header table. The new - maximum size of the header table is encoded on 32-bit. The - decoder MUST reduce its own header table by dropping entries from - it until the size of the header table is lower than or equal to - the transmitted maximum size. + The header field name representation is followed by the header field + value represented as a literal string as described in Section 4.1.2. -6. Security Considerations +5. Security Considerations This compressor exists to solve security issues present in stream compressors such as DEFLATE whereby the compression context can be efficiently probed to reveal secrets. A conformant implementation of this specification should be fairly safe against that kind of attack, as the reaping of any information from the compression context requires more work than guessing and verifying the plaintext data directly with the server. As with any secret, however, the longer the length of the secret, the more difficult the secret is to guess. It is inadvisable to have short cookies that are relied upon to remain secret for any duration of time. A proper security-conscious implementation will also need to prevent timing attacks by ensuring that the amount of time it takes to do string comparisons is always a function of the total length of the strings, and not a function of the number of matched characters. + A decoder needs to ensure that larger values or encodings of integers + do not permit exploitation. Decoders MUST limit the size of + integers, both in value and encoded length, that it accepts (see + Section 4.1.1). + Another common security problem is when the remote endpoint successfully causes the local endpoint to exhaust its memory. This compressor attempts to deal with the most obvious ways that this could occur by limiting both the peak and the steady-state amount of memory consumed in the compressor state, by providing ways for the - application to consume/flush the emitted headers in small chunks, and - by considering overhead in the state size calculation. Implementors - must still be careful in the creation of APIs to an implementation of - this compressor by ensuring that header keys and values are either - emitted as a stream, or that the compression implementation have a - limit on the maximum size of a key or value. Failure to implement - these kinds of safeguards may still result in a scenario where the - local endpoint exhausts its memory. - -7. IANA Considerations - - This document registers the SETTINGS_HEADER_TABLE_SIZE setting in the - "HTTP/2.0 Settings" registry established by [HTTP2]. The assigned - code for this setting is TBD. + application to consume/flush the emitted header fields in small + chunks, and by considering overhead in the state size calculation. + Implementors must still be careful in the creation of APIs to an + implementation of this compressor by ensuring that header field keys + and values are either emitted as a stream, or that the compression + implementation have a limit on the maximum size of a key or value. + Failure to implement these kinds of safeguards may still result in a + scenario where the local endpoint exhausts its memory. -8. References +6. References +6.1. Normative References -8.1. Normative References + [HTTP-p1] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer + Protocol (HTTP/1.1): Message Syntax and Routing", + draft-ietf-httpbis-p1-messaging-24 (work in progress), + September 2013. [HTTP2] Belshe, M., Peon, R., Thomson, M., and A. Melnikov, "Hypertext Transfer Protocol version 2.0", draft-ietf-httpbis-http2-06 (work in progress), - February 2013. + August 2013. -8.2. Informative References +6.2. Informative References - [CRIME] Rizzo, J. and T. Duong, "The Crime Attack", September 2012, - . + + [CRIME] Rizzo, J. and T. Duong, "The Crime Attack", + September 2012, . + [HUFF] Huffman, D., "A Method for the Construction of Minimim + Redundancy Codes", Proceedings of the Institute of Radio + Engineers Volume 40, Number 9, pp. 1098-1101, + September 1952, . + [PERF1] Belshe, M., "IETF83: SPDY and What to Consider for - HTTP/2.0", March 2012, . + HTTP/2.0", March 2012, . - [PERF2] McManus, P., "SPDY What I Like About You", September 2011, < - http://bitsup.blogspot.com/2011/09/ + [PERF2] McManus, P., "SPDY: What I Like About You", + September 2011, . - [SPDY] Belshe, M. and R. Peon, "SPDY Protocol", February 2012, - . + [SPDY] Belshe, M. and R. Peon, "SPDY Protocol", + draft-mbelshe-httpbis-spdy-00 (work in progress), + February 2012. URIs [1] Appendix A. Change Log (to be removed by RFC Editor before publication -A.1. Since draft-ietf-httpbis-header-compression-01 +A.1. Since draft-ietf-httpbis-header-compression-03 + + o A large number of editorial changes; changed the description of + evicting/adding new entries. + + o Removed substitution indexing + + o Changed 'initial headers' to 'static headers', as per issue #258 + + o Merged 'request' and 'response' static headers, as per issue #259 + + o Changed text to indicate that new headers are added at index 0 and + expire from the largest index, as per issue #233 + +A.2. Since draft-ietf-httpbis-header-compression-02 + + o Corrected error in integer encoding pseudocode. + +A.3. Since draft-ietf-httpbis-header-compression-01 o Refactored of Header Encoding Section: split definitions and processing rule. o Backward incompatible change: Updated reference set management as per issue #214. This changes how the interaction between the reference set and eviction works. This also changes the working of the reference set in some specific cases. o Backward incompatible change: modified initial header list, as per @@ -766,21 +829,21 @@ o Added example of 32 bytes entry structure (issue #191). o Added Header Set Completion section. Reflowed some text. Clarified some writing which was akward. Added text about duplicate header entry encoding. Clarified some language w.r.t Header Set. Changed x-my-header to mynewheader. Added text in the HeaderEmission section indicating that the application may also be able to free up memory more quickly. Added information in Security Considerations section. -A.2. Since draft-ietf-httpbis-header-compression-01 +A.4. Since draft-ietf-httpbis-header-compression-01 Fixed bug/omission in integer representation algorithm. Changed the document title. Header matching text rewritten. Changed the definition of header emission. Changed the name of the setting which dictates how much memory the @@ -780,243 +843,1853 @@ Changed the document title. Header matching text rewritten. Changed the definition of header emission. Changed the name of the setting which dictates how much memory the compression context should use. Removed "specific use cases" section + Corrected erroneous statement about what index can be contained in one byte Added descriptions of opcodes Removed security claims from introduction. -Appendix B. Initial Header Tables +Appendix B. Static Table - [[anchor11: The tables in this section should be updated based on - statistical analysis of header names frequency and specific HTTP 2.0 - header rules (like removal of some headers).]] - [[anchor12: These tables are not adapted for headers contained in - PUSH_PROMISE frames. Either the tables can be merged, or the table - for responses can be updated.]] + The static table consists of an unchangable ordered list of (name, + value) pairs. The first entry in the table is always represented by + the index len(header table), and the last entry in the table is + represented by the index len(header table)+len(static table)-1. -B.1. Requests + [[anchor9: The ordering of these tables is currently arbitrary. The + tables in this section should be updated and ordered such that the + table entries with the smallest indices are those which, based on a + statistical analysis of the frequency of use weighted by size, + achieve the largest decrease in bytes transmitted subject to HTTP 2.0 + header field rules (like removal of some header fields). This set of + header fields is currently very likely incomplete, and should be made + complete.]] - The following table lists the pre-defined headers that make-up the - initial header table user to represent requests sent from a client to - a server. + The following table lists the pre-defined header fields that make-up + the static header table. - +-------+---------------------+--------------+ + +-------+-----------------------------+--------------+ | Index | Header Name | Header Value | - +-------+---------------------+--------------+ - | 0 | :scheme | http | - | 1 | :scheme | https | - | 2 | :host | | + +-------+-----------------------------+--------------+ + | 0 | :authority | | + | 1 | :method | GET | + | 2 | :method | POST | | 3 | :path | / | - | 4 | :method | GET | - | 5 | accept | | - | 6 | accept-charset | | - | 7 | accept-encoding | | - | 8 | accept-language | | - | 9 | cookie | | - | 10 | if-modified-since | | - | 11 | user-agent | | - | 12 | referer | | - | 13 | authorization | | - | 14 | allow | | - | 15 | cache-control | | - | 16 | connection | | - | 17 | content-length | | - | 18 | content-type | | - | 19 | date | | - | 20 | expect | | - | 21 | from | | - | 22 | if-match | | - | 23 | if-none-match | | - | 24 | if-range | | - | 25 | if-unmodified-since | | - | 26 | max-forwards | | - | 27 | proxy-authorization | | - | 28 | range | | - | 29 | via | | - +-------+---------------------+--------------+ + | 4 | :path | /index.html | + | 5 | :scheme | http | + | 6 | :scheme | https | + | 7 | :status | 200 | + | 8 | :status | 500 | + | 9 | :status | 404 | + | 10 | :status | 403 | + | 11 | :status | 400 | + | 12 | :status | 401 | + | 13 | accept-charset | | + | 14 | accept-encoding | | + | 15 | accept-language | | + | 16 | accept-ranges | | + | 17 | accept | | + | 18 | access-control-allow-origin | | + | 19 | age | | + | 20 | allow | | + | 21 | authorization | | + | 22 | cache-control | | + | 23 | content-disposition | | + | 24 | content-encoding | | + | 25 | content-language | | + | 26 | content-length | | + | 27 | content-location | | + | 28 | content-range | | + | 29 | content-type | | + | 30 | cookie | | + | 31 | date | | + | 32 | etag | | + | 33 | expect | | + | 34 | expires | | + | 35 | from | | + | 36 | if-match | | + | 37 | if-modified-since | | + | 38 | if-none-match | | + | 39 | if-range | | + | 40 | if-unmodified-since | | + | 41 | last-modified | | + | 42 | link | | + | 43 | location | | + | 44 | max-forwards | | + | 45 | proxy-authenticate | | + | 46 | proxy-authorization | | + | 47 | range | | + | 48 | referer | | + | 49 | refresh | | + | 50 | retry-after | | + | 51 | server | | + | 52 | set-cookie | | + | 53 | strict-transport-security | | + | 54 | transfer-encoding | | + | 55 | user-agent | | + | 56 | vary | | + | 57 | via | | + | 58 | www-authenticate | | + +-------+-----------------------------+--------------+ - Table 1: Initial Header Table for Requests + Table 1: Static Table Entries -B.2. Responses + The table give the index of each entry in the static table. The full + index of each entry, to be used for encoding a reference to this + entry, is computed by adding the number of entries in the header + table to this index. - The following table lists the pre-defined headers that make-up the - initial header table used to represent responses sent from a server - to a client. The same header table is also used to represent request - headers sent from a server to a client in a PUSH_PROMISE frame. +Appendix C. Huffman Codes For Requests - +-------+-----------------------------+--------------+ - | Index | Header Name | Header Value | - +-------+-----------------------------+--------------+ - | 0 | :status | 200 | - | 1 | age | | - | 2 | cache-control | | - | 3 | content-length | | - | 4 | content-type | | - | 5 | date | | - | 6 | etag | | - | 7 | expires | | - | 8 | last-modified | | - | 9 | server | | - | 10 | set-cookie | | - | 11 | vary | | - | 12 | via | | - | 13 | access-control-allow-origin | | - | 14 | accept-ranges | | - | 15 | allow | | - | 16 | connection | | - | 17 | content-disposition | | - | 18 | content-encoding | | - | 19 | content-language | | - | 20 | content-location | | - | 21 | content-range | | - | 22 | link | | - | 23 | location | | - | 24 | proxy-authenticate | | - | 25 | refresh | | - | 26 | retry-after | | - | 27 | strict-transport-security | | - | 28 | transfer-encoding | | - | 29 | www-authenticate | | - +-------+-----------------------------+--------------+ + The following Huffman codes are used when encoding string literals in + the client to server direction. - Table 2: Initial Header Table for Responses + [[anchor10: This table is out of date and needs updating. In + particular, EOS needs to be at least 7-bits long and currently is + not.]] -Appendix C. Example + aligned aligned + to len to len + MSB in LSB in + sym as bits bits as hex bits + ( 0) |11111111|11111111|11110111|010 [27] 7ffffba [27] + ( 1) |11111111|11111111|11110111|011 [27] 7ffffbb [27] + ( 2) |11111111|11111111|11110111|100 [27] 7ffffbc [27] + ( 3) |11111111|11111111|11110111|101 [27] 7ffffbd [27] + ( 4) |11111111|11111111|11110111|110 [27] 7ffffbe [27] + ( 5) |11111111|11111111|11110111|111 [27] 7ffffbf [27] + ( 6) |11111111|11111111|11111000|000 [27] 7ffffc0 [27] + ( 7) |11111111|11111111|11111000|001 [27] 7ffffc1 [27] + ( 8) |11111111|11111111|11111000|010 [27] 7ffffc2 [27] + ( 9) |11111111|11111111|11111000|011 [27] 7ffffc3 [27] + ( 10) |11111111|11111111|11111000|100 [27] 7ffffc4 [27] + ( 11) |11111111|11111111|11111000|101 [27] 7ffffc5 [27] + ( 12) |11111111|11111111|11111000|110 [27] 7ffffc6 [27] + ( 13) |11111111|11111111|11111000|111 [27] 7ffffc7 [27] + ( 14) |11111111|11111111|11111001|000 [27] 7ffffc8 [27] + ( 15) |11111111|11111111|11111001|001 [27] 7ffffc9 [27] + ( 16) |11111111|11111111|11111001|010 [27] 7ffffca [27] + ( 17) |11111111|11111111|11111001|011 [27] 7ffffcb [27] + ( 18) |11111111|11111111|11111001|100 [27] 7ffffcc [27] + ( 19) |11111111|11111111|11111001|101 [27] 7ffffcd [27] + ( 20) |11111111|11111111|11111001|110 [27] 7ffffce [27] + ( 21) |11111111|11111111|11111001|111 [27] 7ffffcf [27] + ( 22) |11111111|11111111|11111010|000 [27] 7ffffd0 [27] + ( 23) |11111111|11111111|11111010|001 [27] 7ffffd1 [27] + ( 24) |11111111|11111111|11111010|010 [27] 7ffffd2 [27] + ( 25) |11111111|11111111|11111010|011 [27] 7ffffd3 [27] + ( 26) |11111111|11111111|11111010|100 [27] 7ffffd4 [27] + ( 27) |11111111|11111111|11111010|101 [27] 7ffffd5 [27] + ( 28) |11111111|11111111|11111010|110 [27] 7ffffd6 [27] + ( 29) |11111111|11111111|11111010|111 [27] 7ffffd7 [27] + ( 30) |11111111|11111111|11111011|000 [27] 7ffffd8 [27] + ( 31) |11111111|11111111|11111011|001 [27] 7ffffd9 [27] + ' ' ( 32) |11101000| [8] e8 [8] + '!' ( 33) |11111111|1100 [12] ffc [12] + '"' ( 34) |11111111|111010 [14] 3ffa [14] + '#' ( 35) |11111111|1111100 [15] 7ffc [15] + '$' ( 36) |11111111|1111101 [15] 7ffd [15] + '%' ( 37) |100100 [6] 24 [6] + '&' ( 38) |1101110 [7] 6e [7] + ''' ( 39) |11111111|1111110 [15] 7ffe [15] + '(' ( 40) |11111111|010 [11] 7fa [11] + ')' ( 41) |11111111|011 [11] 7fb [11] + '*' ( 42) |11111110|10 [10] 3fa [10] + '+' ( 43) |11111111|100 [11] 7fc [11] + ',' ( 44) |11101001| [8] e9 [8] + '-' ( 45) |100101 [6] 25 [6] + '.' ( 46) |00100 [5] 4 [5] + '/' ( 47) |0000 [4] 0 [4] + '0' ( 48) |00101 [5] 5 [5] + '1' ( 49) |00110 [5] 6 [5] + '2' ( 50) |00111 [5] 7 [5] + '3' ( 51) |100110 [6] 26 [6] + '4' ( 52) |100111 [6] 27 [6] + '5' ( 53) |101000 [6] 28 [6] + '6' ( 54) |101001 [6] 29 [6] + '7' ( 55) |101010 [6] 2a [6] + '8' ( 56) |101011 [6] 2b [6] + '9' ( 57) |101100 [6] 2c [6] + ':' ( 58) |11110110|0 [9] 1ec [9] + ';' ( 59) |11101010| [8] ea [8] + '<' ( 60) |11111111|11111111|10 [18] 3fffe [18] + '=' ( 61) |101101 [6] 2d [6] + '>' ( 62) |11111111|11111110|0 [17] 1fffc [17] + '?' ( 63) |11110110|1 [9] 1ed [9] + '@' ( 64) |11111111|111011 [14] 3ffb [14] + 'A' ( 65) |1101111 [7] 6f [7] + 'B' ( 66) |11101011| [8] eb [8] + 'C' ( 67) |11101100| [8] ec [8] + 'D' ( 68) |11101101| [8] ed [8] + 'E' ( 69) |11101110| [8] ee [8] + 'F' ( 70) |1110000 [7] 70 [7] + 'G' ( 71) |11110111|0 [9] 1ee [9] + 'H' ( 72) |11110111|1 [9] 1ef [9] + 'I' ( 73) |11111000|0 [9] 1f0 [9] + 'J' ( 74) |11111000|1 [9] 1f1 [9] + 'K' ( 75) |11111110|11 [10] 3fb [10] + 'L' ( 76) |11111001|0 [9] 1f2 [9] + 'M' ( 77) |11101111| [8] ef [8] + 'N' ( 78) |11111001|1 [9] 1f3 [9] + 'O' ( 79) |11111010|0 [9] 1f4 [9] + 'P' ( 80) |11111010|1 [9] 1f5 [9] + 'Q' ( 81) |11111011|0 [9] 1f6 [9] + 'R' ( 82) |11111011|1 [9] 1f7 [9] + 'S' ( 83) |11110000| [8] f0 [8] + 'T' ( 84) |11110001| [8] f1 [8] + 'U' ( 85) |11111100|0 [9] 1f8 [9] + 'V' ( 86) |11111100|1 [9] 1f9 [9] + 'W' ( 87) |11111101|0 [9] 1fa [9] + 'X' ( 88) |11111101|1 [9] 1fb [9] + 'Y' ( 89) |11111110|0 [9] 1fc [9] + 'Z' ( 90) |11111111|00 [10] 3fc [10] + '[' ( 91) |11111111|111100 [14] 3ffc [14] + '\' ( 92) |11111111|11111111|11111011|010 [27] 7ffffda [27] + ']' ( 93) |11111111|11100 [13] 1ffc [13] + '^' ( 94) |11111111|111101 [14] 3ffd [14] + '_' ( 95) |101110 [6] 2e [6] + '`' ( 96) |11111111|11111111|110 [19] 7fffe [19] + 'a' ( 97) |01000 [5] 8 [5] + 'b' ( 98) |101111 [6] 2f [6] + 'c' ( 99) |01001 [5] 9 [5] + 'd' (100) |110000 [6] 30 [6] + 'e' (101) |0001 [4] 1 [4] + 'f' (102) |110001 [6] 31 [6] + 'g' (103) |110010 [6] 32 [6] + 'h' (104) |110011 [6] 33 [6] + 'i' (105) |01010 [5] a [5] + 'j' (106) |1110001 [7] 71 [7] + 'k' (107) |1110010 [7] 72 [7] + 'l' (108) |01011 [5] b [5] + 'm' (109) |110100 [6] 34 [6] + 'n' (110) |01100 [5] c [5] + 'o' (111) |01101 [5] d [5] + 'p' (112) |01110 [5] e [5] + 'q' (113) |11110010| [8] f2 [8] + 'r' (114) |01111 [5] f [5] + 's' (115) |10000 [5] 10 [5] + 't' (116) |10001 [5] 11 [5] + 'u' (117) |110101 [6] 35 [6] + 'v' (118) |1110011 [7] 73 [7] + 'w' (119) |110110 [6] 36 [6] + 'x' (120) |11110011| [8] f3 [8] + 'y' (121) |11110100| [8] f4 [8] + 'z' (122) |11110101| [8] f5 [8] + '{' (123) |11111111|11111110|1 [17] 1fffd [17] + '|' (124) |11111111|101 [11] 7fd [11] + '}' (125) |11111111|11111111|0 [17] 1fffe [17] + '~' (126) |11111111|1101 [12] ffd [12] + (127) |11111111|11111111|11111011|011 [27] 7ffffdb [27] + (128) |11111111|11111111|11111011|100 [27] 7ffffdc [27] + (129) |11111111|11111111|11111011|101 [27] 7ffffdd [27] + (130) |11111111|11111111|11111011|110 [27] 7ffffde [27] + (131) |11111111|11111111|11111011|111 [27] 7ffffdf [27] + (132) |11111111|11111111|11111100|000 [27] 7ffffe0 [27] + (133) |11111111|11111111|11111100|001 [27] 7ffffe1 [27] + (134) |11111111|11111111|11111100|010 [27] 7ffffe2 [27] + (135) |11111111|11111111|11111100|011 [27] 7ffffe3 [27] + (136) |11111111|11111111|11111100|100 [27] 7ffffe4 [27] + (137) |11111111|11111111|11111100|101 [27] 7ffffe5 [27] + (138) |11111111|11111111|11111100|110 [27] 7ffffe6 [27] + (139) |11111111|11111111|11111100|111 [27] 7ffffe7 [27] + (140) |11111111|11111111|11111101|000 [27] 7ffffe8 [27] + (141) |11111111|11111111|11111101|001 [27] 7ffffe9 [27] + (142) |11111111|11111111|11111101|010 [27] 7ffffea [27] + (143) |11111111|11111111|11111101|011 [27] 7ffffeb [27] + (144) |11111111|11111111|11111101|100 [27] 7ffffec [27] + (145) |11111111|11111111|11111101|101 [27] 7ffffed [27] + (146) |11111111|11111111|11111101|110 [27] 7ffffee [27] + (147) |11111111|11111111|11111101|111 [27] 7ffffef [27] + (148) |11111111|11111111|11111110|000 [27] 7fffff0 [27] + (149) |11111111|11111111|11111110|001 [27] 7fffff1 [27] + (150) |11111111|11111111|11111110|010 [27] 7fffff2 [27] + (151) |11111111|11111111|11111110|011 [27] 7fffff3 [27] + (152) |11111111|11111111|11111110|100 [27] 7fffff4 [27] + (153) |11111111|11111111|11111110|101 [27] 7fffff5 [27] + (154) |11111111|11111111|11111110|110 [27] 7fffff6 [27] + (155) |11111111|11111111|11111110|111 [27] 7fffff7 [27] + (156) |11111111|11111111|11111111|000 [27] 7fffff8 [27] + (157) |11111111|11111111|11111111|001 [27] 7fffff9 [27] + (158) |11111111|11111111|11111111|010 [27] 7fffffa [27] + (159) |11111111|11111111|11111111|011 [27] 7fffffb [27] + (160) |11111111|11111111|11111111|100 [27] 7fffffc [27] + (161) |11111111|11111111|11111111|101 [27] 7fffffd [27] + (162) |11111111|11111111|11111111|110 [27] 7fffffe [27] + (163) |11111111|11111111|11111111|111 [27] 7ffffff [27] + (164) |11111111|11111111|11100000|00 [26] 3ffff80 [26] + (165) |11111111|11111111|11100000|01 [26] 3ffff81 [26] + (166) |11111111|11111111|11100000|10 [26] 3ffff82 [26] + (167) |11111111|11111111|11100000|11 [26] 3ffff83 [26] + (168) |11111111|11111111|11100001|00 [26] 3ffff84 [26] + (169) |11111111|11111111|11100001|01 [26] 3ffff85 [26] + (170) |11111111|11111111|11100001|10 [26] 3ffff86 [26] + (171) |11111111|11111111|11100001|11 [26] 3ffff87 [26] + (172) |11111111|11111111|11100010|00 [26] 3ffff88 [26] + (173) |11111111|11111111|11100010|01 [26] 3ffff89 [26] + (174) |11111111|11111111|11100010|10 [26] 3ffff8a [26] + (175) |11111111|11111111|11100010|11 [26] 3ffff8b [26] + (176) |11111111|11111111|11100011|00 [26] 3ffff8c [26] + (177) |11111111|11111111|11100011|01 [26] 3ffff8d [26] + (178) |11111111|11111111|11100011|10 [26] 3ffff8e [26] + (179) |11111111|11111111|11100011|11 [26] 3ffff8f [26] + (180) |11111111|11111111|11100100|00 [26] 3ffff90 [26] + (181) |11111111|11111111|11100100|01 [26] 3ffff91 [26] + (182) |11111111|11111111|11100100|10 [26] 3ffff92 [26] + (183) |11111111|11111111|11100100|11 [26] 3ffff93 [26] + (184) |11111111|11111111|11100101|00 [26] 3ffff94 [26] + (185) |11111111|11111111|11100101|01 [26] 3ffff95 [26] + (186) |11111111|11111111|11100101|10 [26] 3ffff96 [26] + (187) |11111111|11111111|11100101|11 [26] 3ffff97 [26] + (188) |11111111|11111111|11100110|00 [26] 3ffff98 [26] + (189) |11111111|11111111|11100110|01 [26] 3ffff99 [26] + (190) |11111111|11111111|11100110|10 [26] 3ffff9a [26] + (191) |11111111|11111111|11100110|11 [26] 3ffff9b [26] + (192) |11111111|11111111|11100111|00 [26] 3ffff9c [26] + (193) |11111111|11111111|11100111|01 [26] 3ffff9d [26] + (194) |11111111|11111111|11100111|10 [26] 3ffff9e [26] + (195) |11111111|11111111|11100111|11 [26] 3ffff9f [26] + (196) |11111111|11111111|11101000|00 [26] 3ffffa0 [26] + (197) |11111111|11111111|11101000|01 [26] 3ffffa1 [26] + (198) |11111111|11111111|11101000|10 [26] 3ffffa2 [26] + (199) |11111111|11111111|11101000|11 [26] 3ffffa3 [26] + (200) |11111111|11111111|11101001|00 [26] 3ffffa4 [26] + (201) |11111111|11111111|11101001|01 [26] 3ffffa5 [26] + (202) |11111111|11111111|11101001|10 [26] 3ffffa6 [26] + (203) |11111111|11111111|11101001|11 [26] 3ffffa7 [26] + (204) |11111111|11111111|11101010|00 [26] 3ffffa8 [26] + (205) |11111111|11111111|11101010|01 [26] 3ffffa9 [26] + (206) |11111111|11111111|11101010|10 [26] 3ffffaa [26] + (207) |11111111|11111111|11101010|11 [26] 3ffffab [26] + (208) |11111111|11111111|11101011|00 [26] 3ffffac [26] + (209) |11111111|11111111|11101011|01 [26] 3ffffad [26] + (210) |11111111|11111111|11101011|10 [26] 3ffffae [26] + (211) |11111111|11111111|11101011|11 [26] 3ffffaf [26] + (212) |11111111|11111111|11101100|00 [26] 3ffffb0 [26] + (213) |11111111|11111111|11101100|01 [26] 3ffffb1 [26] + (214) |11111111|11111111|11101100|10 [26] 3ffffb2 [26] + (215) |11111111|11111111|11101100|11 [26] 3ffffb3 [26] + (216) |11111111|11111111|11101101|00 [26] 3ffffb4 [26] + (217) |11111111|11111111|11101101|01 [26] 3ffffb5 [26] + (218) |11111111|11111111|11101101|10 [26] 3ffffb6 [26] + (219) |11111111|11111111|11101101|11 [26] 3ffffb7 [26] + (220) |11111111|11111111|11101110|00 [26] 3ffffb8 [26] + (221) |11111111|11111111|11101110|01 [26] 3ffffb9 [26] + (222) |11111111|11111111|11101110|10 [26] 3ffffba [26] + (223) |11111111|11111111|11101110|11 [26] 3ffffbb [26] + (224) |11111111|11111111|11101111|00 [26] 3ffffbc [26] + (225) |11111111|11111111|11101111|01 [26] 3ffffbd [26] + (226) |11111111|11111111|11101111|10 [26] 3ffffbe [26] + (227) |11111111|11111111|11101111|11 [26] 3ffffbf [26] + (228) |11111111|11111111|11110000|00 [26] 3ffffc0 [26] + (229) |11111111|11111111|11110000|01 [26] 3ffffc1 [26] + (230) |11111111|11111111|11110000|10 [26] 3ffffc2 [26] + (231) |11111111|11111111|11110000|11 [26] 3ffffc3 [26] + (232) |11111111|11111111|11110001|00 [26] 3ffffc4 [26] + (233) |11111111|11111111|11110001|01 [26] 3ffffc5 [26] + (234) |11111111|11111111|11110001|10 [26] 3ffffc6 [26] + (235) |11111111|11111111|11110001|11 [26] 3ffffc7 [26] + (236) |11111111|11111111|11110010|00 [26] 3ffffc8 [26] + (237) |11111111|11111111|11110010|01 [26] 3ffffc9 [26] + (238) |11111111|11111111|11110010|10 [26] 3ffffca [26] + (239) |11111111|11111111|11110010|11 [26] 3ffffcb [26] + (240) |11111111|11111111|11110011|00 [26] 3ffffcc [26] + (241) |11111111|11111111|11110011|01 [26] 3ffffcd [26] + (242) |11111111|11111111|11110011|10 [26] 3ffffce [26] + (243) |11111111|11111111|11110011|11 [26] 3ffffcf [26] + (244) |11111111|11111111|11110100|00 [26] 3ffffd0 [26] + (245) |11111111|11111111|11110100|01 [26] 3ffffd1 [26] + (246) |11111111|11111111|11110100|10 [26] 3ffffd2 [26] + (247) |11111111|11111111|11110100|11 [26] 3ffffd3 [26] + (248) |11111111|11111111|11110101|00 [26] 3ffffd4 [26] + (249) |11111111|11111111|11110101|01 [26] 3ffffd5 [26] + (250) |11111111|11111111|11110101|10 [26] 3ffffd6 [26] + (251) |11111111|11111111|11110101|11 [26] 3ffffd7 [26] + (252) |11111111|11111111|11110110|00 [26] 3ffffd8 [26] + (253) |11111111|11111111|11110110|01 [26] 3ffffd9 [26] + (254) |11111111|11111111|11110110|10 [26] 3ffffda [26] + (255) |11111111|11111111|11110110|11 [26] 3ffffdb [26] + EOS (256) |11111111|11111111|11110111|00 [26] 3ffffdc [26] - Here is an example that illustrates different representations and how - tables are updated. [[anchor15: This section needs to be updated to - better reflect the new processing of header fields, and include more - examples.]] +Appendix D. Huffman Codes for Responses -C.1. First header set + The following Huffman codes are used when encoding string literals in + the server to client direction. - The first header set to represent is the following: + [[anchor11: This table is out of date and needs updating. In + particular, EOS needs to be at least 7-bits long and currently is + not.]] - :path: /my-example/index.html - user-agent: my-user-agent - mynewheader: first + aligned aligned + to len to len + MSB in LSB in + sym as bits bits as hex bits + ( 0) |11111111|11111111|11011110|0 [25] 1ffffbc [25] + ( 1) |11111111|11111111|11011110|1 [25] 1ffffbd [25] + ( 2) |11111111|11111111|11011111|0 [25] 1ffffbe [25] + ( 3) |11111111|11111111|11011111|1 [25] 1ffffbf [25] + ( 4) |11111111|11111111|11100000|0 [25] 1ffffc0 [25] + ( 5) |11111111|11111111|11100000|1 [25] 1ffffc1 [25] + ( 6) |11111111|11111111|11100001|0 [25] 1ffffc2 [25] + ( 7) |11111111|11111111|11100001|1 [25] 1ffffc3 [25] + ( 8) |11111111|11111111|11100010|0 [25] 1ffffc4 [25] + ( 9) |11111111|11111111|11100010|1 [25] 1ffffc5 [25] + ( 10) |11111111|11111111|11100011|0 [25] 1ffffc6 [25] + ( 11) |11111111|11111111|11100011|1 [25] 1ffffc7 [25] + ( 12) |11111111|11111111|11100100|0 [25] 1ffffc8 [25] + ( 13) |11111111|11111111|11100100|1 [25] 1ffffc9 [25] + ( 14) |11111111|11111111|11100101|0 [25] 1ffffca [25] + ( 15) |11111111|11111111|11100101|1 [25] 1ffffcb [25] + ( 16) |11111111|11111111|11100110|0 [25] 1ffffcc [25] + ( 17) |11111111|11111111|11100110|1 [25] 1ffffcd [25] + ( 18) |11111111|11111111|11100111|0 [25] 1ffffce [25] + ( 19) |11111111|11111111|11100111|1 [25] 1ffffcf [25] + ( 20) |11111111|11111111|11101000|0 [25] 1ffffd0 [25] + ( 21) |11111111|11111111|11101000|1 [25] 1ffffd1 [25] + ( 22) |11111111|11111111|11101001|0 [25] 1ffffd2 [25] + ( 23) |11111111|11111111|11101001|1 [25] 1ffffd3 [25] + ( 24) |11111111|11111111|11101010|0 [25] 1ffffd4 [25] + ( 25) |11111111|11111111|11101010|1 [25] 1ffffd5 [25] + ( 26) |11111111|11111111|11101011|0 [25] 1ffffd6 [25] + ( 27) |11111111|11111111|11101011|1 [25] 1ffffd7 [25] + ( 28) |11111111|11111111|11101100|0 [25] 1ffffd8 [25] + ( 29) |11111111|11111111|11101100|1 [25] 1ffffd9 [25] + ( 30) |11111111|11111111|11101101|0 [25] 1ffffda [25] + ( 31) |11111111|11111111|11101101|1 [25] 1ffffdb [25] + ' ' ( 32) |0000 [4] 0 [4] + '!' ( 33) |11111111|1010 [12] ffa [12] + '"' ( 34) |1101010 [7] 6a [7] + '#' ( 35) |11111111|11010 [13] 1ffa [13] + '$' ( 36) |11111111|111100 [14] 3ffc [14] + '%' ( 37) |11110110|0 [9] 1ec [9] + '&' ( 38) |11111110|00 [10] 3f8 [10] + ''' ( 39) |11111111|11011 [13] 1ffb [13] + '(' ( 40) |11110110|1 [9] 1ed [9] + ')' ( 41) |11110111|0 [9] 1ee [9] + '*' ( 42) |11111111|1011 [12] ffb [12] + '+' ( 43) |11111111|010 [11] 7fa [11] + ',' ( 44) |100010 [6] 22 [6] + '-' ( 45) |100011 [6] 23 [6] + '.' ( 46) |100100 [6] 24 [6] + '/' ( 47) |1101011 [7] 6b [7] + '0' ( 48) |0001 [4] 1 [4] + '1' ( 49) |0010 [4] 2 [4] + '2' ( 50) |0011 [4] 3 [4] + '3' ( 51) |01000 [5] 8 [5] + '4' ( 52) |01001 [5] 9 [5] + '5' ( 53) |01010 [5] a [5] + '6' ( 54) |100101 [6] 25 [6] + '7' ( 55) |100110 [6] 26 [6] + '8' ( 56) |01011 [5] b [5] + '9' ( 57) |01100 [5] c [5] + ':' ( 58) |01101 [5] d [5] + ';' ( 59) |11110111|1 [9] 1ef [9] + '<' ( 60) |11111111|11111010| [16] fffa [16] + '=' ( 61) |1101100 [7] 6c [7] + '>' ( 62) |11111111|11100 [13] 1ffc [13] + '?' ( 63) |11111111|1100 [12] ffc [12] + '@' ( 64) |11111111|11111011| [16] fffb [16] + 'A' ( 65) |1101101 [7] 6d [7] + 'B' ( 66) |11101010| [8] ea [8] + 'C' ( 67) |11101011| [8] eb [8] + 'D' ( 68) |11101100| [8] ec [8] + 'E' ( 69) |11101101| [8] ed [8] + 'F' ( 70) |11101110| [8] ee [8] + 'G' ( 71) |100111 [6] 27 [6] + 'H' ( 72) |11111000|0 [9] 1f0 [9] + 'I' ( 73) |11101111| [8] ef [8] + 'J' ( 74) |11110000| [8] f0 [8] + 'K' ( 75) |11111110|01 [10] 3f9 [10] + 'L' ( 76) |11111000|1 [9] 1f1 [9] + 'M' ( 77) |101000 [6] 28 [6] + 'N' ( 78) |11110001| [8] f1 [8] + 'O' ( 79) |11110010| [8] f2 [8] + 'P' ( 80) |11111001|0 [9] 1f2 [9] + 'Q' ( 81) |11111110|10 [10] 3fa [10] + 'R' ( 82) |11111001|1 [9] 1f3 [9] + 'S' ( 83) |101001 [6] 29 [6] + 'T' ( 84) |01110 [5] e [5] + 'U' ( 85) |11111010|0 [9] 1f4 [9] + 'V' ( 86) |11111010|1 [9] 1f5 [9] + 'W' ( 87) |11110011| [8] f3 [8] + 'X' ( 88) |11111110|11 [10] 3fb [10] + 'Y' ( 89) |11111011|0 [9] 1f6 [9] + 'Z' ( 90) |11111111|00 [10] 3fc [10] + '[' ( 91) |11111111|011 [11] 7fb [11] + '\' ( 92) |11111111|11101 [13] 1ffd [13] + ']' ( 93) |11111111|100 [11] 7fc [11] + '^' ( 94) |11111111|1111100 [15] 7ffc [15] + '_' ( 95) |11111011|1 [9] 1f7 [9] + '`' ( 96) |11111111|11111111|0 [17] 1fffe [17] + 'a' ( 97) |01111 [5] f [5] + 'b' ( 98) |1101110 [7] 6e [7] + 'c' ( 99) |101010 [6] 2a [6] + 'd' (100) |101011 [6] 2b [6] + 'e' (101) |10000 [5] 10 [5] + 'f' (102) |1101111 [7] 6f [7] + 'g' (103) |1110000 [7] 70 [7] + 'h' (104) |1110001 [7] 71 [7] + 'i' (105) |101100 [6] 2c [6] + 'j' (106) |11111100|0 [9] 1f8 [9] + 'k' (107) |11111100|1 [9] 1f9 [9] + 'l' (108) |1110010 [7] 72 [7] + 'm' (109) |101101 [6] 2d [6] + 'n' (110) |101110 [6] 2e [6] + 'o' (111) |101111 [6] 2f [6] + 'p' (112) |110000 [6] 30 [6] + 'q' (113) |11111101|0 [9] 1fa [9] + 'r' (114) |110001 [6] 31 [6] + 's' (115) |110010 [6] 32 [6] + 't' (116) |110011 [6] 33 [6] + 'u' (117) |110100 [6] 34 [6] + 'v' (118) |1110011 [7] 73 [7] + 'w' (119) |11110100| [8] f4 [8] + 'x' (120) |1110100 [7] 74 [7] + 'y' (121) |11110101| [8] f5 [8] + 'z' (122) |11111101|1 [9] 1fb [9] + '{' (123) |11111111|11111100| [16] fffc [16] + '|' (124) |11111111|111101 [14] 3ffd [14] + '}' (125) |11111111|11111101| [16] fffd [16] + '~' (126) |11111111|11111110| [16] fffe [16] + (127) |11111111|11111111|11101110|0 [25] 1ffffdc [25] + (128) |11111111|11111111|11101110|1 [25] 1ffffdd [25] + (129) |11111111|11111111|11101111|0 [25] 1ffffde [25] + (130) |11111111|11111111|11101111|1 [25] 1ffffdf [25] + (131) |11111111|11111111|11110000|0 [25] 1ffffe0 [25] + (132) |11111111|11111111|11110000|1 [25] 1ffffe1 [25] + (133) |11111111|11111111|11110001|0 [25] 1ffffe2 [25] + (134) |11111111|11111111|11110001|1 [25] 1ffffe3 [25] + (135) |11111111|11111111|11110010|0 [25] 1ffffe4 [25] + (136) |11111111|11111111|11110010|1 [25] 1ffffe5 [25] + (137) |11111111|11111111|11110011|0 [25] 1ffffe6 [25] + (138) |11111111|11111111|11110011|1 [25] 1ffffe7 [25] + (139) |11111111|11111111|11110100|0 [25] 1ffffe8 [25] + (140) |11111111|11111111|11110100|1 [25] 1ffffe9 [25] + (141) |11111111|11111111|11110101|0 [25] 1ffffea [25] + (142) |11111111|11111111|11110101|1 [25] 1ffffeb [25] + (143) |11111111|11111111|11110110|0 [25] 1ffffec [25] + (144) |11111111|11111111|11110110|1 [25] 1ffffed [25] + (145) |11111111|11111111|11110111|0 [25] 1ffffee [25] + (146) |11111111|11111111|11110111|1 [25] 1ffffef [25] + (147) |11111111|11111111|11111000|0 [25] 1fffff0 [25] + (148) |11111111|11111111|11111000|1 [25] 1fffff1 [25] + (149) |11111111|11111111|11111001|0 [25] 1fffff2 [25] + (150) |11111111|11111111|11111001|1 [25] 1fffff3 [25] + (151) |11111111|11111111|11111010|0 [25] 1fffff4 [25] + (152) |11111111|11111111|11111010|1 [25] 1fffff5 [25] + (153) |11111111|11111111|11111011|0 [25] 1fffff6 [25] + (154) |11111111|11111111|11111011|1 [25] 1fffff7 [25] + (155) |11111111|11111111|11111100|0 [25] 1fffff8 [25] + (156) |11111111|11111111|11111100|1 [25] 1fffff9 [25] + (157) |11111111|11111111|11111101|0 [25] 1fffffa [25] + (158) |11111111|11111111|11111101|1 [25] 1fffffb [25] + (159) |11111111|11111111|11111110|0 [25] 1fffffc [25] + (160) |11111111|11111111|11111110|1 [25] 1fffffd [25] + (161) |11111111|11111111|11111111|0 [25] 1fffffe [25] + (162) |11111111|11111111|11111111|1 [25] 1ffffff [25] + (163) |11111111|11111111|10000000| [24] ffff80 [24] + (164) |11111111|11111111|10000001| [24] ffff81 [24] + (165) |11111111|11111111|10000010| [24] ffff82 [24] + (166) |11111111|11111111|10000011| [24] ffff83 [24] + (167) |11111111|11111111|10000100| [24] ffff84 [24] + (168) |11111111|11111111|10000101| [24] ffff85 [24] + (169) |11111111|11111111|10000110| [24] ffff86 [24] + (170) |11111111|11111111|10000111| [24] ffff87 [24] + (171) |11111111|11111111|10001000| [24] ffff88 [24] + (172) |11111111|11111111|10001001| [24] ffff89 [24] + (173) |11111111|11111111|10001010| [24] ffff8a [24] + (174) |11111111|11111111|10001011| [24] ffff8b [24] + (175) |11111111|11111111|10001100| [24] ffff8c [24] + (176) |11111111|11111111|10001101| [24] ffff8d [24] + (177) |11111111|11111111|10001110| [24] ffff8e [24] + (178) |11111111|11111111|10001111| [24] ffff8f [24] + (179) |11111111|11111111|10010000| [24] ffff90 [24] + (180) |11111111|11111111|10010001| [24] ffff91 [24] + (181) |11111111|11111111|10010010| [24] ffff92 [24] + (182) |11111111|11111111|10010011| [24] ffff93 [24] + (183) |11111111|11111111|10010100| [24] ffff94 [24] + (184) |11111111|11111111|10010101| [24] ffff95 [24] + (185) |11111111|11111111|10010110| [24] ffff96 [24] + (186) |11111111|11111111|10010111| [24] ffff97 [24] + (187) |11111111|11111111|10011000| [24] ffff98 [24] + (188) |11111111|11111111|10011001| [24] ffff99 [24] + (189) |11111111|11111111|10011010| [24] ffff9a [24] + (190) |11111111|11111111|10011011| [24] ffff9b [24] + (191) |11111111|11111111|10011100| [24] ffff9c [24] + (192) |11111111|11111111|10011101| [24] ffff9d [24] + (193) |11111111|11111111|10011110| [24] ffff9e [24] + (194) |11111111|11111111|10011111| [24] ffff9f [24] + (195) |11111111|11111111|10100000| [24] ffffa0 [24] + (196) |11111111|11111111|10100001| [24] ffffa1 [24] + (197) |11111111|11111111|10100010| [24] ffffa2 [24] + (198) |11111111|11111111|10100011| [24] ffffa3 [24] + (199) |11111111|11111111|10100100| [24] ffffa4 [24] + (200) |11111111|11111111|10100101| [24] ffffa5 [24] + (201) |11111111|11111111|10100110| [24] ffffa6 [24] + (202) |11111111|11111111|10100111| [24] ffffa7 [24] + (203) |11111111|11111111|10101000| [24] ffffa8 [24] + (204) |11111111|11111111|10101001| [24] ffffa9 [24] + (205) |11111111|11111111|10101010| [24] ffffaa [24] + (206) |11111111|11111111|10101011| [24] ffffab [24] + (207) |11111111|11111111|10101100| [24] ffffac [24] + (208) |11111111|11111111|10101101| [24] ffffad [24] + (209) |11111111|11111111|10101110| [24] ffffae [24] + (210) |11111111|11111111|10101111| [24] ffffaf [24] + (211) |11111111|11111111|10110000| [24] ffffb0 [24] + (212) |11111111|11111111|10110001| [24] ffffb1 [24] + (213) |11111111|11111111|10110010| [24] ffffb2 [24] + (214) |11111111|11111111|10110011| [24] ffffb3 [24] + (215) |11111111|11111111|10110100| [24] ffffb4 [24] + (216) |11111111|11111111|10110101| [24] ffffb5 [24] + (217) |11111111|11111111|10110110| [24] ffffb6 [24] + (218) |11111111|11111111|10110111| [24] ffffb7 [24] + (219) |11111111|11111111|10111000| [24] ffffb8 [24] + (220) |11111111|11111111|10111001| [24] ffffb9 [24] + (221) |11111111|11111111|10111010| [24] ffffba [24] + (222) |11111111|11111111|10111011| [24] ffffbb [24] + (223) |11111111|11111111|10111100| [24] ffffbc [24] + (224) |11111111|11111111|10111101| [24] ffffbd [24] + (225) |11111111|11111111|10111110| [24] ffffbe [24] + (226) |11111111|11111111|10111111| [24] ffffbf [24] + (227) |11111111|11111111|11000000| [24] ffffc0 [24] + (228) |11111111|11111111|11000001| [24] ffffc1 [24] + (229) |11111111|11111111|11000010| [24] ffffc2 [24] + (230) |11111111|11111111|11000011| [24] ffffc3 [24] + (231) |11111111|11111111|11000100| [24] ffffc4 [24] + (232) |11111111|11111111|11000101| [24] ffffc5 [24] + (233) |11111111|11111111|11000110| [24] ffffc6 [24] + (234) |11111111|11111111|11000111| [24] ffffc7 [24] + (235) |11111111|11111111|11001000| [24] ffffc8 [24] + (236) |11111111|11111111|11001001| [24] ffffc9 [24] + (237) |11111111|11111111|11001010| [24] ffffca [24] + (238) |11111111|11111111|11001011| [24] ffffcb [24] + (239) |11111111|11111111|11001100| [24] ffffcc [24] + (240) |11111111|11111111|11001101| [24] ffffcd [24] + (241) |11111111|11111111|11001110| [24] ffffce [24] + (242) |11111111|11111111|11001111| [24] ffffcf [24] + (243) |11111111|11111111|11010000| [24] ffffd0 [24] + (244) |11111111|11111111|11010001| [24] ffffd1 [24] + (245) |11111111|11111111|11010010| [24] ffffd2 [24] + (246) |11111111|11111111|11010011| [24] ffffd3 [24] + (247) |11111111|11111111|11010100| [24] ffffd4 [24] + (248) |11111111|11111111|11010101| [24] ffffd5 [24] + (249) |11111111|11111111|11010110| [24] ffffd6 [24] + (250) |11111111|11111111|11010111| [24] ffffd7 [24] + (251) |11111111|11111111|11011000| [24] ffffd8 [24] + (252) |11111111|11111111|11011001| [24] ffffd9 [24] + (253) |11111111|11111111|11011010| [24] ffffda [24] + (254) |11111111|11111111|11011011| [24] ffffdb [24] + (255) |11111111|11111111|11011100| [24] ffffdc [24] + EOS (256) |11111111|11111111|11011101| [24] ffffdd [24] - The header table is empty, all headers are represented as literal - headers with indexing. The 'mynewheader' header name is not in the - header name table and is encoded literally. This gives the following - representation: +Appendix E. Examples - 0x44 (literal header with incremental indexing, name index = 3) - 0x16 (header value string length = 22) - /my-example/index.html - 0x4D (literal header with incremental indexing, name index = 12) - 0x0D (header value string length = 13) - my-user-agent - 0x40 (literal header with incremental indexing, new name) - 0x0B (header name string length = 11) - mynewheader - 0x05 (header value string length = 5) - first + A number of examples are worked through here, for both requests and + responses, and with and without huffman coding. - The header table is as follows after the processing of these headers: +E.1. Request Decoding Example With Huffman - Header table - +---------+----------------+---------------------------+ - | Index | Header Name | Header Value | - +---------+----------------+---------------------------+ - | 0 | :scheme | http | - +---------+----------------+---------------------------+ - | 1 | :scheme | https | - +---------+----------------+---------------------------+ - | ... | ... | ... | - +---------+----------------+---------------------------+ - | 37 | warning | | - +---------+----------------+---------------------------+ - | 38 | :path | /my-example/index.html | added header - +---------+----------------+---------------------------+ - | 39 | user-agent | my-user-agent | added header - +---------+----------------+---------------------------+ - | 40 | mynewheader | first | added header - +---------+----------------+---------------------------+ + # Header set to be encoded + :method: GET + :scheme: http + :path: / + :authority: www.foo.com + # Hexdump of encoded data which will be decoded + 02 84 f7 77 78 ff 07 83 ce 31 77 06 81 0f 04 88 | ...wx....1w..... + db 6d 89 8b 5a 44 b7 4f | .m..ZD.O - As all the headers in the first header set are indexed in the header - table, all are kept in the reference set of headers, which is: + # Decoded opcodes + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '02' + name_index: + encoded: "02" + decoded: 2 + value_data_length: + encoded: "84" + decoded: 4 + value_data: + is_huffman_encoded: 1 + encoded: "f77778ff" + decoded: "GET" - Reference Set: - :path, /my-example/index.html - user-agent, my-user-agent - mynewheader, first + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '07' + name_index: + encoded: "07" + decoded: 7 + value_data_length: + encoded: "83" + decoded: 3 + value_data: + is_huffman_encoded: 1 + encoded: "ce3177" + decoded: "http" -C.2. Second header set + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '06' + name_index: + encoded: "06" + decoded: 6 + value_data_length: + encoded: "81" + decoded: 1 + value_data: + is_huffman_encoded: 1 + encoded: "0f" + decoded: "/" - The second header set to represent is the following: + LITERAL_INCREMENTAL_OPCODE: - :path: /my-example/resources/script.js - user-agent: my-user-agent - mynewheader: second + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '04' + name_index: + encoded: "04" + decoded: 4 + value_data_length: + encoded: "88" + decoded: 8 + value_data: + is_huffman_encoded: 1 + encoded: "db6d898b5a44b74f" + decoded: "www.foo.com" - Comparing this second header set to the reference set, the first and - third headers are from the reference set are not present in this - second header set and must be removed. In addition, in this new set, - the first and third headers have to be encoded. The path header is - represented as a literal header with substitution indexing. The - mynewheader will be represented as a literal header with incremental - indexing. + # Decoded header set + :authority: www.foo.com + :method: GET + :path: / + :scheme: http - 0xa6 (indexed header, index = 38: removal from reference set) - 0xa8 (indexed header, index = 40: removal from reference set) - 0x04 (literal header, substitution indexing, name index = 3) - 0x26 (replaced entry index = 38) - 0x1f (header value string length = 31) - /my-example/resources/script.js - 0x5f 0x0a (literal header, incremental indexing, name index = 40) - 0x06 (header value string length = 6) - second + ######################### - The header table is updated as follow: + # Header set to be encoded + :method: GET + :scheme: https + :path: / + :authority: www.bar.com + cache-control: no-cache - Header table - +---------+----------------+---------------------------+ - | Index | Header Name | Header Value | - +---------+----------------+---------------------------+ - | 0 | :scheme | http | - +---------+----------------+---------------------------+ - | 1 | :scheme | https | - +---------+----------------+---------------------------+ - | ... | ... | ... | - +---------+----------------+---------------------------+ - | 37 | warning | | - +---------+----------------+---------------------------+ - | 38 | :path | /my-example/resources/ | replaced - | | | script.js | header - +---------+----------------+---------------------------+ - | 39 | user-agent | my-user-agent | - +---------+----------------+---------------------------+ - | 40 | mynewheader | first | - +---------+----------------+---------------------------+ - | 41 | mynewheader | second | added header - +---------+----------------+---------------------------+ + # Hexdump of encoded data which will be decoded + 03 84 ce 31 74 3f 02 88 db 6d 89 7a 1e 44 b7 4f | ...1t?...m.z.D.O + 1d 86 63 65 4a 13 98 ff 83 85 | ..ceJ..... - All the headers in this second header set are indexed in the header - table, therefore, all are kept in the reference set of headers, which - becomes: + # Decoded opcodes + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '03' + name_index: + encoded: "03" + decoded: 3 + value_data_length: + encoded: "84" + decoded: 4 + value_data: + is_huffman_encoded: 1 + encoded: "ce31743f" + decoded: "https" - Reference Set: - :path, /my-example/resources/script.js - user-agent, my-user-agent - mynewheader, second + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '02' + name_index: + encoded: "02" + decoded: 2 + value_data_length: + encoded: "88" + decoded: 8 + value_data: + is_huffman_encoded: 1 + encoded: "db6d897a1e44b74f" + decoded: "www.bar.com" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '1d' + name_index: + encoded: "1d" + decoded: 29 + value_data_length: + encoded: "86" + decoded: 6 + value_data: + is_huffman_encoded: 1 + encoded: "63654a1398ff" + decoded: "no-cache" + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '83' + entry_index: + encoded: "83" + decoded: 3 + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '85' + entry_index: + encoded: "85" + decoded: 5 + + # Decoded header set + :authority: www.bar.com + :method: GET + :path: / + :scheme: https + cache-control: no-cache + + ######################### + + # Header set to be encoded + :method: GET + :scheme: https + :path: /custom-path.css + :authority: www.bar.com + custom-key: custom-value + + # Hexdump of encoded data which will be decoded + 05 8b 04 eb 08 b7 49 5c 88 e6 44 c2 1f 00 88 4e | ......I\..D....N + b0 8b 74 97 90 fa 7f 89 4e b0 8b 74 97 9a 17 a8 | ..t.....N..t.... + ff 82 86 | ... + + # Decoded opcodes + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '05' + name_index: + encoded: "05" + decoded: 5 + value_data_length: + encoded: "8b" + decoded: 11 + value_data: + is_huffman_encoded: 1 + encoded: "04eb08b7495c88e644c21f" + decoded: "/custom-path.css" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '00' + name_index: + encoded: "00" + decoded: 0 + name_data_length: + encoded: "88" + decoded: 8 + name_data: + is_huffman_encoded: 1 + encoded: "4eb08b749790fa7f" + decoded: "custom-key" + value_data_length: + encoded: "89" + decoded: 9 + value_data: + + is_huffman_encoded: 1 + encoded: "4eb08b74979a17a8ff" + decoded: "custom-value" + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '82' + entry_index: + encoded: "82" + decoded: 2 + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '86' + entry_index: + encoded: "86" + decoded: 6 + + # Decoded header set + :authority: www.bar.com + :method: GET + :path: /custom-path.css + :scheme: https + custom-key: custom-value + + ######################### + +E.2. Request Decoding Example Without Huffman + + # Header set to be encoded + :method: GET + :scheme: http + :path: / + :authority: www.foo.com + + # Hexdump of encoded data which will be decoded + 02 03 47 45 54 07 04 68 74 74 70 06 01 2f 04 0b | ..GET..http../.. + 77 77 77 2e 66 6f 6f 2e 63 6f 6d | www.foo.com + + # Decoded opcodes + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '02' + name_index: + + encoded: "02" + decoded: 2 + value_data_length: + encoded: "03" + decoded: 3 + value_data: + is_huffman_encoded: 0 + encoded: "474554" + decoded: "GET" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '07' + name_index: + encoded: "07" + decoded: 7 + value_data_length: + encoded: "04" + decoded: 4 + value_data: + is_huffman_encoded: 0 + encoded: "68747470" + decoded: "http" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '06' + name_index: + encoded: "06" + decoded: 6 + value_data_length: + encoded: "01" + decoded: 1 + value_data: + is_huffman_encoded: 0 + encoded: "2f" + decoded: "/" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '04' + name_index: + encoded: "04" + decoded: 4 + value_data_length: + encoded: "0b" + decoded: 11 + value_data: + + is_huffman_encoded: 0 + encoded: "7777772e666f6f2e636f6d" + decoded: "www.foo.com" + + # Decoded header set + :authority: www.foo.com + :method: GET + :path: / + :scheme: http + + ######################### + + # Header set to be encoded + :method: GET + :scheme: https + :path: / + :authority: www.bar.com + cache-control: no-cache + + # Hexdump of encoded data which will be decoded + 03 05 68 74 74 70 73 02 0b 77 77 77 2e 62 61 72 | ..https..www.bar + 2e 63 6f 6d 1d 08 6e 6f 2d 63 61 63 68 65 83 85 | .com..no-cache.. + + # Decoded opcodes + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '03' + name_index: + encoded: "03" + decoded: 3 + value_data_length: + encoded: "05" + decoded: 5 + value_data: + is_huffman_encoded: 0 + encoded: "6874747073" + decoded: "https" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '02' + name_index: + encoded: "02" + decoded: 2 + value_data_length: + encoded: "0b" + decoded: 11 + + value_data: + is_huffman_encoded: 0 + encoded: "7777772e6261722e636f6d" + decoded: "www.bar.com" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '1d' + name_index: + encoded: "1d" + decoded: 29 + value_data_length: + encoded: "08" + decoded: 8 + value_data: + is_huffman_encoded: 0 + encoded: "6e6f2d6361636865" + decoded: "no-cache" + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '83' + entry_index: + encoded: "83" + decoded: 3 + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '85' + entry_index: + encoded: "85" + decoded: 5 + + # Decoded header set + :authority: www.bar.com + :method: GET + :path: / + :scheme: https + cache-control: no-cache + + ######################### + + # Header set to be encoded + :method: GET + :scheme: https + :path: /custom-path.css + :authority: www.bar.com + custom-key: custom-value + + # Hexdump of encoded data which will be decoded + 05 10 2f 63 75 73 74 6f 6d 2d 70 61 74 68 2e 63 | ../custom-path.c + 73 73 00 0a 63 75 73 74 6f 6d 2d 6b 65 79 0c 63 | ss..custom-key.c + 75 73 74 6f 6d 2d 76 61 6c 75 65 82 86 | ustom-value.. + + # Decoded opcodes + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '05' + name_index: + encoded: "05" + decoded: 5 + value_data_length: + encoded: "10" + decoded: 16 + value_data: + is_huffman_encoded: 0 + encoded: "2f637573746f6d2d706174682e637373" + decoded: "/custom-path.css" + + LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '00' + name_index: + encoded: "00" + decoded: 0 + name_data_length: + encoded: "0a" + decoded: 10 + name_data: + is_huffman_encoded: 0 + encoded: "637573746f6d2d6b6579" + decoded: "custom-key" + value_data_length: + encoded: "0c" + decoded: 12 + value_data: + is_huffman_encoded: 0 + encoded: "637573746f6d2d76616c7565" + decoded: "custom-value" + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '82' + entry_index: + encoded: "82" + decoded: 2 + + INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '86' + entry_index: + encoded: "86" + decoded: 6 + + # Decoded header set + :authority: www.bar.com + :method: GET + :path: /custom-path.css + :scheme: https + custom-key: custom-value + + ######################### + +E.3. Response Decoding Example With Huffman + +# Header set to be encoded +:status: 302 +cache-control: private +date: Mon, 21 OCt 2013 20:13:21 GMT +location: : https://www.bar.com + +# Hexdump of encoded data which will be decoded +08 82 40 9f 18 86 c3 1b 39 bf 38 7f 22 92 a2 fb | ..@.....9.8."... +a2 03 20 f2 eb cc 0c 49 00 62 d2 43 4c 82 7a 1d | .. ....I.b.CL.z. +2f 91 68 71 cf 3c 32 6e bd 7e 9e 9e 92 6e 7e 32 | /.hq.<2n.~...n~2 +55 7d bf | U}. + +# Decoded opcodes +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '08' + name_index: + encoded: "08" + decoded: 8 + value_data_length: + encoded: "82" + decoded: 2 + value_data: + is_huffman_encoded: 1 + encoded: "409f" + decoded: "302" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '18' + name_index: + encoded: "18" + decoded: 24 + value_data_length: + encoded: "86" + decoded: 6 + value_data: + is_huffman_encoded: 1 + encoded: "c31b39bf387f" + decoded: "private" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '22' + name_index: + encoded: "22" + decoded: 34 + value_data_length: + encoded: "92" + decoded: 18 + value_data: + is_huffman_encoded: 1 + encoded: "a2fba20320f2ebcc0c490062d2434c827a1d" + decoded: "Mon, 21 OCt 2013 20:13:21 GMT" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '2f' + name_index: + encoded: "2f" + decoded: 47 + value_data_length: + encoded: "91" + decoded: 17 + value_data: + is_huffman_encoded: 1 + encoded: "6871cf3c326ebd7e9e9e926e7e32557dbf" + decoded: ": https://www.bar.com" + +# Decoded header set +:status: 302 +cache-control: private +date: Mon, 21 OCt 2013 20:13:21 GMT +location: : https://www.bar.com + +######################### + +# Header set to be encoded +:status: 200 +cache-control: private +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +content-encoding: gzip +set-cookie: foo=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAALASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ1234 max-age=3600; version=1 + +# Hexdump of encoded data which will be decoded +04 82 31 1f 03 92 a2 fb a2 03 20 f2 eb cc 0c 49 | ..1....... ....I +00 62 d2 43 4c c2 7a 1d 03 90 e3 9e 78 64 dd 7a | .b.CL.z.....xd.z +fd 3d 3d 24 dc fc 64 aa fb 7f 20 84 e1 fb b3 0f | .==$..d... ..... +3d ff ee 02 df 7d fb 36 ed db b7 6e dd bb 76 ed | =....}.6...n..v. +db b7 6e dd bb 76 ed db b7 6e dd bb 76 ed db b7 | ..n..v...n..v... +6e dd bb 76 ed db b7 6e dd bb 76 ed db b7 6e dd | n..v...n..v...n. +bb 76 ed db b7 6e dd bb 76 ed db b7 6e dd bb 76 | .v...n..v...n..v +ed db b7 6e dd bb 7e 3b 69 ec f0 fe 7e 1f d7 f3 | ...n..~;i...~... +d5 fe 7f 7e 5f d7 9f 6f 97 cb bf e9 b7 fb fe bc | ...~_..o........ +fb 7c bb fe 9b 7f bf 8f 87 f3 f0 fe bc fc bb 7b | .|.............{ +fe 9b 7e 3f d7 9f 6f 97 7f d3 6f f7 f1 fe bb 7e | ..~?..o...o....~ +9b 7f bf 8f c7 f9 f0 db 4f 67 f5 e7 db e5 f4 ef | ........Og...... +db fd f8 91 a1 3f 1d b4 f6 78 7f 3f 0f eb f9 ea | .....?...x.?.... +ff 3f bf 2f eb cf b7 cb e5 df f4 db fd ff 5e 7d | .?./..........^} +be 5d ff 4d bf df c7 c3 f9 f8 7f 5e 7e 5d bd ff | .].M.......^~].. +4d bf 1f eb cf b7 cb bf e9 b7 fb f8 ff 5d bf 4d | M............].M +bf df c7 e3 fc f8 6d a7 b3 fa f3 ed f2 fa 77 ed | ......m.......w. +fe fc 48 d0 9f 8e da 7b 3c 3f 9f 87 f5 fc f5 7f | ..H....{. +2e ff a6 df ef e3 e1 fc fc 3f af 3f 2e de ff a6 | .........?.?.... +df 8f f5 e7 db e5 df f4 db fd fc 7f ae df a6 df | ................ +ef e3 f1 fe 7c 36 d3 d9 fd 79 f6 f9 7d 3b f6 ff | ....|6...y..};.. +7e 24 68 4f c7 6d 3d 9e 1f cf c3 fa fe 7a bf cf | ~$hO.m=......z.. +ef cb fa f3 ed f2 f9 77 fd 36 ff 7f d7 9f 6f 97 | .......w.6....o. +7f d3 6f f7 f1 f0 fe 7e 1f d7 9f 97 6f 7f d3 6f | ..o....~....o..o +c7 fa f3 ed f2 ef fa 6d fe fe 3f d7 6f d3 6f f7 | .......m..?.o.o. +f1 f8 ff 3e 1b 69 ec fe bc fb 7c be 9d fb 7f bf | ...>.i....|..... + +12 34 27 fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f | .4'..?....?....? +cf f3 fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf | ....?....?....?. +f3 fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf f3 | ...?....?....?.. +fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf f3 fc | ..?....?....?... +ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf f3 fc ff | .?....?....?.... +3f cf f3 fc ff 3f cf f3 fc ff 3f cf f0 8d 09 0b | ?....?....?..... +5f d2 37 f0 86 c4 4a 23 ef 0e 70 c7 2b 2f bb 61 | _.7...J#..p.+/.a +7f 85 86 88 | .... + +# Decoded opcodes +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '04' + name_index: + encoded: "04" + decoded: 4 + value_data_length: + encoded: "82" + decoded: 2 + value_data: + is_huffman_encoded: 1 + encoded: "311f" + decoded: "200" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '03' + name_index: + encoded: "03" + decoded: 3 + value_data_length: + encoded: "92" + decoded: 18 + value_data: + is_huffman_encoded: 1 + encoded: "a2fba20320f2ebcc0c490062d2434cc27a1d" + decoded: "Mon, 21 OCt 2013 20:13:22 GMT" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '03' + name_index: + encoded: "03" + decoded: 3 + value_data_length: + encoded: "90" + decoded: 16 + value_data: + + is_huffman_encoded: 1 + encoded: "e39e7864dd7afd3d3d24dcfc64aafb7f" + decoded: "https://www.bar.com" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '20' + name_index: + encoded: "20" + decoded: 32 + value_data_length: + encoded: "84" + decoded: 4 + value_data: + is_huffman_encoded: 1 + encoded: "e1fbb30f" + decoded: "gzip" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '3d' + name_index: + encoded: "3d" + decoded: 61 + value_data_length: + encoded: "ffee02" + decoded: 493 + value_data: + is_huffman_encoded: 1 + encoded: "df7dfb36eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76edd\ +bb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddb\ +b76eddbb7e3b69ecf0fe7e1fd7f3d5fe7f7e5fd79f6f97cbbfe9b7fbfebcfb7cbbfe9b7\ +fbf8f87f3f0febcfcbb7bfe9b7e3fd79f6f977fd36ff7f1febb7e9b7fbf8fc7f9f0db4f\ +67f5e7dbe5f4efdbfdf891a13f1db4f6787f3f0febf9eaff3fbf2febcfb7cbe5dff4dbf\ +dff5e7dbe5dff4dbfdfc7c3f9f87f5e7e5dbdff4dbf1febcfb7cbbfe9b7fbf8ff5dbf4d\ +bfdfc7e3fcf86da7b3faf3edf2fa77edfefc48d09f8eda7b3c3f9f87f5fcf57f9fdf97f\ +5e7dbe5f2effa6dfeffaf3edf2effa6dfefe3e1fcfc3faf3f2edeffa6df8ff5e7dbe5df\ +f4dbfdfc7faedfa6dfefe3f1fe7c36d3d9fd79f6f97d3bf6ff7e24684fc76d3d9e1fcfc\ +3fafe7abfcfefcbfaf3edf2f977fd36ff7fd79f6f977fd36ff7f1f0fe7e1fd79f976f7f\ +d36fc7faf3edf2effa6dfefe3fd76fd36ff7f1f8ff3e1b69ecfebcfb7cbe9dfb7fbf123\ +427fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcf\ +f3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff\ +3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff08d090b5fd237f086c44a23ef0e70c7\ +2b2fbb617f" + decoded: "foo=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAALASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIU\ +AXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQ\ +WEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOE\ +IUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJK\ +HQWOEIUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234ZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ1234max-age=3600; version=1\ +" + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '85' + entry_index: + encoded: "85" + decoded: 5 + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '86' + entry_index: + encoded: "86" + decoded: 6 + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '88' + entry_index: + encoded: "88" + decoded: 8 + +# Decoded header set +:status: 200 +cache-control: private +content-encoding: gzip +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +set-cookie: foo=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAALASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ1234 max-age=3600; version=1 + +######################### + +# Header set to be encoded +:status: 200 +cache-control: private +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +content-encoding: gzip +set-cookie: foo=ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZLASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA1234 max-age=3600; version=1 + +# Hexdump of encoded data which will be decoded +01 ff ee 02 df 7d fb 3f cf f3 fc ff 3f cf f3 fc | .....}.?....?... +ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf f3 fc ff | .?....?....?.... +3f cf f3 fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f | ?....?....?....? +cf f3 fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf | ....?....?....?. +f3 fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf f3 | ...?....?....?.. +fc ff 3f cf f3 fc ff 3f cf f3 fc ff 3f cf f3 fc | ..?....?....?... +ff 3e 3b 69 ec f0 fe 7e 1f d7 f3 d5 fe 7f 7e 5f | .>;i...~......~_ +d7 9f 6f 97 cb bf e9 b7 fb fe bc fb 7c bb fe 9b | ..o.........|... +7f bf 8f 87 f3 f0 fe bc fc bb 7b fe 9b 7e 3f d7 | ..........{..~?. +9f 6f 97 7f d3 6f f7 f1 fe bb 7e 9b 7f bf 8f c7 | .o...o....~..... +f9 f0 db 4f 67 f5 e7 db e5 f4 ef db fd f8 91 a1 | ...Og........... +3f 1d b4 f6 78 7f 3f 0f eb f9 ea ff 3f bf 2f eb | ?...x.?.....?./. +cf b7 cb e5 df f4 db fd ff 5e 7d be 5d ff 4d bf | .........^}.].M. +df c7 c3 f9 f8 7f 5e 7e 5d bd ff 4d bf 1f eb cf | ......^~]..M.... +b7 cb bf e9 b7 fb f8 ff 5d bf 4d bf df c7 e3 fc | ........].M..... +f8 6d a7 b3 fa f3 ed f2 fa 77 ed fe fc 48 d0 9f | .m.......w...H.. +8e da 7b 3c 3f 9f 87 f5 fc f5 7f 9f df 97 f5 e7 | ..{...... +e3 e1 fc fc 3f af 3f 2e de ff a6 df 8f f5 e7 db | ....?.?......... +e5 df f4 db fd fc 7f ae df a6 df ef e3 f1 fe 7c | ...............| +36 d3 d9 fd 79 f6 f9 7d 3b f6 ff 7e 24 68 4f c7 | 6...y..};..~$hO. +6d 3d 9e 1f cf c3 fa fe 7a bf cf ef cb fa f3 ed | m=......z....... +f2 f9 77 fd 36 ff 7f d7 9f 6f 97 7f d3 6f f7 f1 | ..w.6....o...o.. +f0 fe 7e 1f d7 9f 97 6f 7f d3 6f c7 fa f3 ed f2 | ..~....o..o..... +ef fa 6d fe fe 3f d7 6f d3 6f f7 f1 f8 ff 3e 1b | ..m..?.o.o....>. +69 ec fe bc fb 7c be 9d fb 7f bf 12 34 27 6e dd | i....|......4'n. +bb 76 ed db b7 6e dd bb 76 ed db b7 6e dd bb 76 | .v...n..v...n..v +ed db b7 6e dd bb 76 ed db b7 6e dd bb 76 ed db | ...n..v...n..v.. +b7 6e dd bb 76 ed db b7 6e dd bb 76 ed db b7 6e | .n..v...n..v...n +dd bb 76 ed db b7 6e dd bb 76 ed db b4 8d 09 0b | ..v...n..v...... +5f d2 37 f0 86 c4 4a 23 ef 0e 70 c7 2b 2f bb 61 | _.7...J#..p.+/.a +7f 81 | .. +# Decoded opcodes +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '01' + name_index: + + encoded: "01" + decoded: 1 + value_data_length: + encoded: "ffee02" + decoded: 493 + value_data: + is_huffman_encoded: 1 + encoded: "df7dfb3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3f\ +cff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fc\ +ff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3fcff3e3b69ecf\ +0fe7e1fd7f3d5fe7f7e5fd79f6f97cbbfe9b7fbfebcfb7cbbfe9b7fbf8f87f3f0febcfc\ +bb7bfe9b7e3fd79f6f977fd36ff7f1febb7e9b7fbf8fc7f9f0db4f67f5e7dbe5f4efdbf\ +df891a13f1db4f6787f3f0febf9eaff3fbf2febcfb7cbe5dff4dbfdff5e7dbe5dff4dbf\ +dfc7c3f9f87f5e7e5dbdff4dbf1febcfb7cbbfe9b7fbf8ff5dbf4dbfdfc7e3fcf86da7b\ +3faf3edf2fa77edfefc48d09f8eda7b3c3f9f87f5fcf57f9fdf97f5e7dbe5f2effa6dfe\ +ffaf3edf2effa6dfefe3e1fcfc3faf3f2edeffa6df8ff5e7dbe5dff4dbfdfc7faedfa6d\ +fefe3f1fe7c36d3d9fd79f6f97d3bf6ff7e24684fc76d3d9e1fcfc3fafe7abfcfefcbfa\ +f3edf2f977fd36ff7fd79f6f977fd36ff7f1f0fe7e1fd79f976f7fd36fc7faf3edf2eff\ +a6dfefe3fd76fd36ff7f1f8ff3e1b69ecfebcfb7cbe9dfb7fbf1234276eddbb76eddbb7\ +6eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76eddbb76\ +eddbb76eddbb76eddbb76eddbb76eddbb76eddbb48d090b5fd237f086c44a23ef0e70c7\ +2b2fbb617f" + decoded: "foo=ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZLASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIU\ +AXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQ\ +WEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOE\ +IUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJK\ +HQWOEIUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234AAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA1234max-age=3600; version=1\ +" + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '81' + entry_index: + encoded: "81" + decoded: 1 + +# Decoded header set +:status: 200 +cache-control: private +content-encoding: gzip +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +set-cookie: foo=ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZLASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA1234 max-age=3600; version=1 + +######################### + +E.4. Response Decoding Example Without Huffman + +# Header set to be encoded +:status: 302 +cache-control: private +date: Mon, 21 OCt 2013 20:13:21 GMT +location: : https://www.bar.com + +# Hexdump of encoded data which will be decoded +08 03 33 30 32 18 07 70 72 69 76 61 74 65 22 1d | ..302..private". +4d 6f 6e 2c 20 32 31 20 4f 43 74 20 32 30 31 33 | Mon, 21 OCt 2013 +20 32 30 3a 31 33 3a 32 31 20 47 4d 54 2f 15 3a | 20:13:21 GMT/.: +20 68 74 74 70 73 3a 2f 2f 77 77 77 2e 62 61 72 | https://www.bar +2e 63 6f 6d | .com + +# Decoded opcodes +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '08' + name_index: + encoded: "08" + decoded: 8 + value_data_length: + encoded: "03" + decoded: 3 + value_data: + is_huffman_encoded: 0 + encoded: "333032" + decoded: "302" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '18' + name_index: + encoded: "18" + decoded: 24 + value_data_length: + encoded: "07" + decoded: 7 + value_data: + is_huffman_encoded: 0 + encoded: "70726976617465" + decoded: "private" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '22' + name_index: + encoded: "22" + decoded: 34 + value_data_length: + encoded: "1d" + decoded: 29 + value_data: + is_huffman_encoded: 0 + encoded: "4d6f6e2c203231204f437420323031332032303a31333a3231204\ +74d54" + decoded: "Mon, 21 OCt 2013 20:13:21 GMT" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '2f' + name_index: + encoded: "2f" + decoded: 47 + value_data_length: + encoded: "15" + decoded: 21 + value_data: + is_huffman_encoded: 0 + encoded: "3a2068747470733a2f2f7777772e6261722e636f6d" + decoded: ": https://www.bar.com" + +# Decoded header set +:status: 302 +cache-control: private +date: Mon, 21 OCt 2013 20:13:21 GMT +location: : https://www.bar.com + +######################### + +# Header set to be encoded +:status: 200 +cache-control: private +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +content-encoding: gzip +set-cookie: foo=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAALASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ1234 max-age=3600; version=1 + +# Hexdump of encoded data which will be decoded +04 03 32 30 30 03 1d 4d 6f 6e 2c 20 32 31 20 4f | ..200..Mon, 21 O +43 74 20 32 30 31 33 20 32 30 3a 31 33 3a 32 32 | Ct 2013 20:13:22 +20 47 4d 54 03 13 68 74 74 70 73 3a 2f 2f 77 77 | GMT..https://ww +77 2e 62 61 72 2e 63 6f 6d 20 04 67 7a 69 70 3d | w.bar.com .gzip= +7f e1 02 66 6f 6f 3d 41 41 41 41 41 41 41 41 41 | ...foo=AAAAAAAAA +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 | AAAAAAAAAAAAAAAA +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 | AAAAAAAAAAAAAAAA +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 | AAAAAAAAAAAAAAAA +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 4c | AAAAAAAAAAAAAAAL +41 53 44 4a 4b 48 51 4b 42 5a 58 4f 51 57 45 4f | ASDJKHQKBZXOQWEO +50 49 55 41 58 51 57 45 4f 49 55 41 58 4c 4a 4b | PIUAXQWEOIUAXLJK +48 51 57 4f 45 49 55 41 4c 51 57 45 4f 49 55 41 | HQWOEIUALQWEOIUA +58 4c 51 45 55 41 58 4c 4c 4b 4a 41 53 44 51 57 | XLQEUAXLLKJASDQW +45 4f 55 49 41 58 4e 31 32 33 34 4c 41 53 44 4a | EOUIAXN1234LASDJ +4b 48 51 4b 42 5a 58 4f 51 57 45 4f 50 49 55 41 | KHQKBZXOQWEOPIUA +58 51 57 45 4f 49 55 41 58 4c 4a 4b 48 51 57 4f | XQWEOIUAXLJKHQWO +45 49 55 41 4c 51 57 45 4f 49 55 41 58 4c 51 45 | EIUALQWEOIUAXLQE +55 41 58 4c 4c 4b 4a 41 53 44 51 57 45 4f 55 49 | UAXLLKJASDQWEOUI +41 58 4e 31 32 33 34 4c 41 53 44 4a 4b 48 51 4b | AXN1234LASDJKHQK +42 5a 58 4f 51 57 45 4f 50 49 55 41 58 51 57 45 | BZXOQWEOPIUAXQWE +4f 49 55 41 58 4c 4a 4b 48 51 57 4f 45 49 55 41 | OIUAXLJKHQWOEIUA +4c 51 57 45 4f 49 55 41 58 4c 51 45 55 41 58 4c | LQWEOIUAXLQEUAXL +4c 4b 4a 41 53 44 51 57 45 4f 55 49 41 58 4e 31 | LKJASDQWEOUIAXN1 +32 33 34 4c 41 53 44 4a 4b 48 51 4b 42 5a 58 4f | 234LASDJKHQKBZXO +51 57 45 4f 50 49 55 41 58 51 57 45 4f 49 55 41 | QWEOPIUAXQWEOIUA +58 4c 4a 4b 48 51 57 4f 45 49 55 41 4c 51 57 45 | XLJKHQWOEIUALQWE +4f 49 55 41 58 4c 51 45 55 41 58 4c 4c 4b 4a 41 | OIUAXLQEUAXLLKJA +53 44 51 57 45 4f 55 49 41 58 4e 31 32 33 34 5a | SDQWEOUIAXN1234Z +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 31 32 33 34 20 6d 61 78 2d | ZZZZZZZ1234 max- +61 67 65 3d 33 36 30 30 3b 20 76 65 72 73 69 6f | age=3600; versio +6e 3d 31 85 86 88 | n=1... + +# Decoded opcodes +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '04' + name_index: + encoded: "04" + decoded: 4 + value_data_length: + encoded: "03" + decoded: 3 + value_data: + is_huffman_encoded: 0 + encoded: "323030" + decoded: "200" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '03' + name_index: + encoded: "03" + decoded: 3 + value_data_length: + encoded: "1d" + decoded: 29 + value_data: + is_huffman_encoded: 0 + encoded: "4d6f6e2c203231204f437420323031332032303a31333a3232204\ +74d54" + decoded: "Mon, 21 OCt 2013 20:13:22 GMT" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '03' + name_index: + encoded: "03" + decoded: 3 + value_data_length: + encoded: "13" + decoded: 19 + value_data: + is_huffman_encoded: 0 + encoded: "68747470733a2f2f7777772e6261722e636f6d" + decoded: "https://www.bar.com" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '20' + name_index: + encoded: "20" + decoded: 32 + value_data_length: + encoded: "04" + decoded: 4 + value_data: + is_huffman_encoded: 0 + encoded: "677a6970" + decoded: "gzip" + +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '3d' + name_index: + encoded: "3d" + decoded: 61 + value_data_length: + encoded: "7fe102" + decoded: 480 + value_data: + is_huffman_encoded: 0 + encoded: "666f6f3d414141414141414141414141414141414141414141414\ +14141414141414141414141414141414141414141414141414141414141414141414141\ +41414141414141414141414141414c4153444a4b48514b425a584f5157454f504955415\ +85157454f495541584c4a4b4851574f454955414c5157454f495541584c51455541584c\ +4c4b4a4153445157454f554941584e313233344c4153444a4b48514b425a584f5157454\ +f50495541585157454f495541584c4a4b4851574f454955414c5157454f495541584c51\ +455541584c4c4b4a4153445157454f554941584e313233344c4153444a4b48514b425a5\ +84f5157454f50495541585157454f495541584c4a4b4851574f454955414c5157454f49\ +5541584c51455541584c4c4b4a4153445157454f554941584e313233344c4153444a4b4\ +8514b425a584f5157454f50495541585157454f495541584c4a4b4851574f454955414c\ +5157454f495541584c51455541584c4c4b4a4153445157454f554941584e313233345a5\ +a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a\ +5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a3\ +1323334206d61782d6167653d333630303b2076657273696f6e3d31" + decoded: "foo=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAALASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIU\ +AXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQ\ +WEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOE\ +IUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJK\ +HQWOEIUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234ZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ1234max-age=3600; version=1\ +" + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '85' + entry_index: + encoded: "85" + decoded: 5 + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '86' + entry_index: + encoded: "86" + decoded: 6 + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '88' + entry_index: + encoded: "88" + decoded: 8 + +# Decoded header set +:status: 200 +cache-control: private +content-encoding: gzip +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +set-cookie: foo=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAALASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ1234 max-age=3600; version=1 + +######################### + +# Header set to be encoded +:status: 200 +cache-control: private +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +content-encoding: gzip +set-cookie: foo=ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZLASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA1234 max-age=3600; version=1 + +# Hexdump of encoded data which will be decoded +01 7f e1 02 66 6f 6f 3d 5a 5a 5a 5a 5a 5a 5a 5a | ....foo=ZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a | ZZZZZZZZZZZZZZZZ +4c 41 53 44 4a 4b 48 51 4b 42 5a 58 4f 51 57 45 | LASDJKHQKBZXOQWE +4f 50 49 55 41 58 51 57 45 4f 49 55 41 58 4c 4a | OPIUAXQWEOIUAXLJ +4b 48 51 57 4f 45 49 55 41 4c 51 57 45 4f 49 55 | KHQWOEIUALQWEOIU +41 58 4c 51 45 55 41 58 4c 4c 4b 4a 41 53 44 51 | AXLQEUAXLLKJASDQ +57 45 4f 55 49 41 58 4e 31 32 33 34 4c 41 53 44 | WEOUIAXN1234LASD +4a 4b 48 51 4b 42 5a 58 4f 51 57 45 4f 50 49 55 | JKHQKBZXOQWEOPIU +41 58 51 57 45 4f 49 55 41 58 4c 4a 4b 48 51 57 | AXQWEOIUAXLJKHQW +4f 45 49 55 41 4c 51 57 45 4f 49 55 41 58 4c 51 | OEIUALQWEOIUAXLQ +45 55 41 58 4c 4c 4b 4a 41 53 44 51 57 45 4f 55 | EUAXLLKJASDQWEOU +49 41 58 4e 31 32 33 34 4c 41 53 44 4a 4b 48 51 | IAXN1234LASDJKHQ +4b 42 5a 58 4f 51 57 45 4f 50 49 55 41 58 51 57 | KBZXOQWEOPIUAXQW +45 4f 49 55 41 58 4c 4a 4b 48 51 57 4f 45 49 55 | EOIUAXLJKHQWOEIU +41 4c 51 57 45 4f 49 55 41 58 4c 51 45 55 41 58 | ALQWEOIUAXLQEUAX +4c 4c 4b 4a 41 53 44 51 57 45 4f 55 49 41 58 4e | LLKJASDQWEOUIAXN +31 32 33 34 4c 41 53 44 4a 4b 48 51 4b 42 5a 58 | 1234LASDJKHQKBZX +4f 51 57 45 4f 50 49 55 41 58 51 57 45 4f 49 55 | OQWEOPIUAXQWEOIU +41 58 4c 4a 4b 48 51 57 4f 45 49 55 41 4c 51 57 | AXLJKHQWOEIUALQW +45 4f 49 55 41 58 4c 51 45 55 41 58 4c 4c 4b 4a | EOIUAXLQEUAXLLKJ +41 53 44 51 57 45 4f 55 49 41 58 4e 31 32 33 34 | ASDQWEOUIAXN1234 +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 | AAAAAAAAAAAAAAAA +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 | AAAAAAAAAAAAAAAA +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 | AAAAAAAAAAAAAAAA +41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 | AAAAAAAAAAAAAAAA +41 41 41 41 41 41 41 41 31 32 33 34 20 6d 61 78 | AAAAAAAA1234 max +2d 61 67 65 3d 33 36 30 30 3b 20 76 65 72 73 69 | -age=3600; versi +6f 6e 3d 31 81 | on=1. + +# Decoded opcodes +LITERAL_INCREMENTAL_OPCODE: + opcodeLengthInBits: 2 + discoveredFromPeekingAtByte: '01' + name_index: + encoded: "01" + decoded: 1 + value_data_length: + encoded: "7fe102" + decoded: 480 + value_data: + is_huffman_encoded: 0 + encoded: "666f6f3d5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5\ +a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a\ +5a5a5a5a5a5a5a5a5a5a5a5a5a5a4c4153444a4b48514b425a584f5157454f504955415\ +85157454f495541584c4a4b4851574f454955414c5157454f495541584c51455541584c\ +4c4b4a4153445157454f554941584e313233344c4153444a4b48514b425a584f5157454\ +f50495541585157454f495541584c4a4b4851574f454955414c5157454f495541584c51\ +455541584c4c4b4a4153445157454f554941584e313233344c4153444a4b48514b425a5\ +84f5157454f50495541585157454f495541584c4a4b4851574f454955414c5157454f49\ +5541584c51455541584c4c4b4a4153445157454f554941584e313233344c4153444a4b4\ +8514b425a584f5157454f50495541585157454f495541584c4a4b4851574f454955414c\ +5157454f495541584c51455541584c4c4b4a4153445157454f554941584e31323334414\ +14141414141414141414141414141414141414141414141414141414141414141414141\ +41414141414141414141414141414141414141414141414141414141414141414141413\ +1323334206d61782d6167653d333630303b2076657273696f6e3d31" + decoded: "foo=ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZZZZZZZLASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIU\ +AXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQ\ +WEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOE\ +IUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJK\ +HQWOEIUALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234AAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA1234max-age=3600; version=1\ +" + +INDEX_OPCODE: + opcodeLengthInBits: 1 + discoveredFromPeekingAtByte: '81' + entry_index: + encoded: "81" + decoded: 1 + +# Decoded header set +:status: 200 +cache-control: private +content-encoding: gzip +date: Mon, 21 OCt 2013 20:13:22 GMT +location: https://www.bar.com +set-cookie: foo=ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ\ +ZZZZZZZZZZZZZZZZZLASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUAXLQEU\ +AXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQWEOIUA\ +XLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEIUALQW\ +EOIUAXLQEUAXLLKJASDQWEOUIAXN1234LASDJKHQKBZXOQWEOPIUAXQWEOIUAXLJKHQWOEI\ +UALQWEOIUAXLQEUAXLLKJASDQWEOUIAXN1234AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\ +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA1234 max-age=3600; version=1 + +######################### Authors' Addresses Roberto Peon Google, Inc EMail: fenix@google.com Herve Ruellan Canon CRF