< draft-mavrogiannopoulos-chacha-tls-01.txt		draft-mavrogiannopoulos-chacha-tls-02.txt >
	Network Working Group A. Langley		Network Working Group A. Langley
	Internet-Draft W. Chang		Internet-Draft W. Chang
	Updates: 5246, 6347 Google Inc		Updates: 5246, 6347 Google Inc
	(if approved) N. Mavrogiannopoulos		(if approved) N. Mavrogiannopoulos
	Intended status: Standards Track Red Hat		Intended status: Standards Track Red Hat
	Expires: July 28, 2014 J. Strombergson		Expires: September 4, 2014 J. Strombergson
	Secworks Sweden AB		Secworks Sweden AB
	S. Josefsson		S. Josefsson
	SJD AB		SJD AB
	January 24, 2014		March 3, 2014
	The ChaCha Stream Cipher for Transport Layer Security		The ChaCha Stream Cipher for Transport Layer Security
	draft-mavrogiannopoulos-chacha-tls-01		draft-mavrogiannopoulos-chacha-tls-02
	Abstract		Abstract
	This document describes the use of the ChaCha stream cipher with		This document describes the use of the ChaCha stream cipher with
	HMAC-SHA1 and Poly1305 in Transport Layer Security (TLS) and Datagram		HMAC-SHA1 and Poly1305 in Transport Layer Security (TLS) and Datagram
	Transport Layer Security (DTLS) protocols.		Transport Layer Security (DTLS) protocols.
	Status of this Memo		Status of this Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	skipping to change at page 1, line 38 ¶		skipping to change at page 1, line 38 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
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	This Internet-Draft will expire on July 28, 2014.		This Internet-Draft will expire on September 4, 2014.
	Copyright Notice		Copyright Notice
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	document authors. All rights reserved.		document authors. All rights reserved.
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	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. The ChaCha Cipher . . . . . . . . . . . . . . . . . . . . . . 4		2. The ChaCha Cipher . . . . . . . . . . . . . . . . . . . . . . 4
	3. The Poly1305 Authenticator . . . . . . . . . . . . . . . . . . 6		3. The Poly1305 Authenticator . . . . . . . . . . . . . . . . . . 5
	4. ChaCha20 Cipher Suites . . . . . . . . . . . . . . . . . . . . 7		4. ChaCha20 Cipher Suites . . . . . . . . . . . . . . . . . . . . 6
	4.1. ChaCha20 Cipher Suites with HMAC-SHA1 . . . . . . . . . . 7		4.1. ChaCha20 Cipher Suites with HMAC-SHA1 . . . . . . . . . . 6
	4.2. ChaCha20 Cipher Suites with Poly1305 . . . . . . . . . . . 7		4.2. ChaCha20 Cipher Suites with Poly1305 . . . . . . . . . . . 7
	5. Updates to the TLS Standard Stream Cipher . . . . . . . . . . 10		5. Updates to the TLS Standard Stream Cipher . . . . . . . . . . 8
	6. Updates to DTLS . . . . . . . . . . . . . . . . . . . . . . . 11		6. Updates to DTLS . . . . . . . . . . . . . . . . . . . . . . . 9
	7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12		7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13		8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
	9. Security Considerations . . . . . . . . . . . . . . . . . . . 14		9. Security Considerations . . . . . . . . . . . . . . . . . . . 12
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15		10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
	10.1. Normative References . . . . . . . . . . . . . . . . . . . 15		10.1. Normative References . . . . . . . . . . . . . . . . . . . 13
	10.2. Informative References . . . . . . . . . . . . . . . . . . 15		10.2. Informative References . . . . . . . . . . . . . . . . . . 13
	Appendix A. Test vectors . . . . . . . . . . . . . . . . . . . . 17		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
	A.1. ChaCha20 . . . . . . . . . . . . . . . . . . . . . . . . . 17
	A.2. Poly1305 . . . . . . . . . . . . . . . . . . . . . . . . . 18
	A.3. AEAD_CHACHA20_POLY1305 . . . . . . . . . . . . . . . . . . 18
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20
	1. Introduction		1. Introduction
	This document describes the use of the ChaCha stream cipher in the		This document describes the use of the ChaCha stream cipher in the
	Transport Layer Security (TLS) version 1.0 [RFC2246], TLS version 1.1		Transport Layer Security (TLS) version 1.0 [RFC2246], TLS version 1.1
	[RFC4346], and TLS version 1.2 [RFC5246] protocols, as well as in the		[RFC4346], and TLS version 1.2 [RFC5246] protocols, as well as in the
	Datagram Transport Layer Security (DTLS) versions 1.0 [RFC4347] and		Datagram Transport Layer Security (DTLS) versions 1.0 [RFC4347] and
	1.2 [RFC6347]. It can also be used with Secure Sockets Layer (SSL)		1.2 [RFC6347]. It can also be used with Secure Sockets Layer (SSL)
	version 3.0 [RFC6101].		version 3.0 [RFC6101].
	skipping to change at page 4, line 11 ¶		skipping to change at page 4, line 11 ¶
	comparable to RC4 in speed on a wide range of platforms and can be		comparable to RC4 in speed on a wide range of platforms and can be
	implemented easily without being vulnerable to software side-channel		implemented easily without being vulnerable to software side-channel
	attacks.		attacks.
	2. The ChaCha Cipher		2. The ChaCha Cipher
	ChaCha [CHACHA] is a stream cipher developed by D. J. Bernstein in		ChaCha [CHACHA] is a stream cipher developed by D. J. Bernstein in
	2008. It is a refinement of Salsa20 and was used as the core of the		2008. It is a refinement of Salsa20 and was used as the core of the
	SHA-3 finalist, BLAKE.		SHA-3 finalist, BLAKE.
	The variant of ChaCha used in this document is ChaCha with 20 rounds		The variant of ChaCha used in this document is ChaCha with 20 rounds,
	and a 256 bit key, which will be referred to as ChaCha20 in the rest		a 96-bit nonce and a 256 bit key, which will be referred to as
	of this document. This is the conservative variant (with respect to		ChaCha20 in the rest of this document. This is the conservative
	security) of the ChaCha family.		variant (with respect to security) of the ChaCha family and is
			described in [I-D.nir-cfrg-chacha20-poly1305].
	ChaCha maps 16, 32-bit input words to 16, 32-bit output words. By
	convention, 8 of the input words consist of a 256-bit key, 4 are
	constants and the remaining four are a nonce and block counter. The
	output words are converted to bytes and XORed with the plaintext to
	produce ciphertext. In order to generate sufficient output bytes to
	XOR with the whole plaintext, the block counter is incremented and
	ChaCha is run again, as many times as needed, for up to 2^70 bytes of
	output.
	ChaCha operates on a state of 16, 32-bit words which are initialised
	from the input words. The first four input words are constants:
	(0x61707865, 0x3320646e, 0x79622d32, 0x6b206574)
	Input words 4 through 11 are taken from the 256-bit key by reading
	the bytes in little-endian order, in 4-byte chunks. Input words 12
	and 13 are a block counter, with word 12 overflowing into word 13.
	Lastly, words 14 and 15 are taken from an 8-byte nonce, again by
	reading the bytes in little-endian order, in 4-byte chunks. The
	block counter words are initially zero.
	ChaCha20 consists of 20 rounds, alternating between "column" rounds
	and "diagonal" rounds. Each round applies the following "quarter-
	round" function four times, to a different set of words each time.
	The quarter-round function updates 4, 32-bit words (a, b, c, d) as
	follows, where <<< is a bitwise, left rotation:
	a += b; d ^= a; d <<<= 16;
	c += d; b ^= c; b <<<= 12;
	a += b; d ^= a; d <<<= 8;
	c += d; b ^= c; b <<<= 7;
	The 16 words are conceptually arranged in a four by four grid with
	the first word in the top-left position and the fourth word in the
	top-right position. The "column" rounds then apply the quarter-round
	function to the four columns, from left to right. The "diagonal"
	rounds apply the quarter-round to the top-left, bottom-right
	diagonal, followed by the pattern shifted one place to the right, for
	three more quarter-rounds.
	Specifically, a column round applies the quarter-round function to
	the following indexes: (0, 4, 8, 12), (1, 5, 9, 13), (2, 6, 10, 14),
	(3, 7, 11, 15). A diagonal round applies it to these indexes: (0, 5,
	10, 15), (1, 6, 11, 12), (2, 7, 8, 13), (3, 4, 9, 14).
	After 20 rounds of the above processing, the original 16 input words
	are added to the 16 words to form the 16 output words.
	The 64 output bytes are generated from the 16 output words by
	serializing them in little-endian order and concatenating the
	results.
	Test vectors for this cipher can be found in Appendix A.1.
	3. The Poly1305 Authenticator		3. The Poly1305 Authenticator
	Poly1305 [POLY1305] is a Wegman-Carter, one-time authenticator		Poly1305 [POLY1305] is a Wegman-Carter, one-time authenticator
	designed by D. J. Bernstein. Poly1305 takes a 32-byte, one-time key		designed by D. J. Bernstein. Poly1305 takes a 32-byte, one-time key
	and a message and produces a 16-byte tag that authenticates the		and a message and produces a 16-byte tag that authenticates the
	message such that an attacker has a negligible chance of producing a		message such that an attacker has a negligible chance of producing a
	valid tag for an inauthentic message.		valid tag for an inauthentic message. It is described in
			[I-D.nir-cfrg-chacha20-poly1305].
	The first 16 bytes of the one-time key form an integer, _r_, as
	follows: the top four bits of the bytes at indexes 3, 7, 11 and 15
	are cleared, the bottom 2 bits of the bytes at indexes 4, 8 and 12
	are cleared and the 16 bytes are taken as a little-endian value.
	An accumulator is set to zero. For each chunk of 16 bytes from the
	input message, a byte with value 1 is appended and the 17 bytes are
	treated as a little-endian number. If the last chunk has less than
	16 bytes then zero bytes are appended after the 1 byte is appended
	until there are 17 bytes. The value is added to the accumulator and
	then the accumulator is multiplied by _r_, all mod 2^130 - 5.
	Finally the last 16 bytes of the one-time key are treated as a
	little-endian number and added to the accumulator, mod 2^128. The
	result is serialised as a little-endian number, producing the 16 byte
	tag. Note that the original specification of Poly1305 used a
	different construction with AES to generate the constant term of the
	polynomial from a counter nonce. For a more recent treatment that
	avoids the use of a block cipher in this fashion, as is done here,
	see section 9 of the NaCl specification [NACLCRYPTO].
	Test vectors for this authenticator can be found in Appendix A.2.
	4. ChaCha20 Cipher Suites		4. ChaCha20 Cipher Suites
	In the next sections different ciphersuites are defined that utilize		In the next sections different ciphersuites are defined that utilize
	the ChaCha20 cipher combined with various message authentication		the ChaCha20 cipher combined with various message authentication
	methods.		methods.
	In all cases, the pseudorandom function (PRF) for TLS 1.2 is the TLS		In all cases, the ChaCha20 cipher, as in
	PRF with SHA-256 as the hash function. When used with TLS versions		[I-D.nir-cfrg-chacha20-poly1305], uses a 96-bit nonce. That nonce is
	prior to 1.2, the PRF is calculated as specified in the appropriate		updated on the encryption of every TLS record, and is formed as
	version of the TLS specification.		follows.
			struct {
			opaque salt[4];
			opaque record_counter[8];
			} ChaChaNonce;
			The salt is generated as part of the handshake process. It is either
			the client_write_IV (when the client is sending) or the
			server_write_IV (when the server is sending). The salt length
			(SecurityParameters.fixed_iv_length) is 4 bytes. The record_counter
			is the 64-bit TLS record sequence number. In case of DTLS the
			record_counter is formed as the concatenation of the 16-bit epoch
			with the 48-bit sequence number.
			In both TLS and DTLS the ChaChaNonce is implicit and not sent as part
			of the packet.
			The pseudorandom function (PRF) for TLS 1.2 is the TLS PRF with SHA-
			256 as the hash function. When used with TLS versions prior to 1.2,
			the PRF is calculated as specified in the appropriate version of the
			TLS specification.
	The RSA, DHE_RSA, ECDHE_RSA, ECDHE_ECDSA, PSK, DHE_PSK, RSA_PSK,		The RSA, DHE_RSA, ECDHE_RSA, ECDHE_ECDSA, PSK, DHE_PSK, RSA_PSK,
	ECDHE_PSK key exchanges are performed as defined in [RFC5246],		ECDHE_PSK key exchanges are performed as defined in [RFC5246],
	[RFC4492], and [RFC5489].		[RFC4492], and [RFC5489].
	4.1. ChaCha20 Cipher Suites with HMAC-SHA1		4.1. ChaCha20 Cipher Suites with HMAC-SHA1
	The following CipherSuites are defined.		The following CipherSuites are defined.
	TLS_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x20}		TLS_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_ECDHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x21}		TLS_ECDHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_ECDHE_ECDSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x22}		TLS_ECDHE_ECDSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_DHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x23}
	TLS_DHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x24}
	TLS_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x25}		TLS_DHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_ECDHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x26}		TLS_DHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_RSA_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x27}
	Note that ChaCha20 requires a 64-bit nonce. That nonce is updated on		TLS_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	the encryption of every TLS record, and is set to be the 64-bit TLS		TLS_ECDHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	record sequence number. In case of DTLS the 64-bit nonce is formed		TLS_RSA_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	as the concatenation of the 16-bit epoch with the 48-bit sequence
	number.
	The MAC algorithm used in the ciphersuites above is HMAC-SHA1		The MAC algorithm used in the ciphersuites above is HMAC-SHA1
	[RFC6234].		[RFC6234].
	4.2. ChaCha20 Cipher Suites with Poly1305		4.2. ChaCha20 Cipher Suites with Poly1305
	The ChaCha20 and Poly1305 primitives are built into an AEAD algorithm		The ChaCha20 and Poly1305 primitives are built into an AEAD algorithm
	[RFC5116], AEAD_CHACHA20_POLY1305, that takes a 32 byte key and 8		[RFC5116], AEAD_CHACHA20_POLY1305, described in
	byte nonce as follows.		[I-D.nir-cfrg-chacha20-poly1305]. It takes as input a 256-bit key
			and a 96-bit nonce.
	ChaCha20 is run with the given key and nonce and with the two counter
	words set to zero. The first 32 bytes of the 64 byte output are
	saved to become the one-time key for Poly1305. The remainder of the
	output is discarded. The first counter input word is set to one and
	the plaintext is encrypted by XORing it with the output of
	invocations of the ChaCha20 function as needed, incrementing the
	first counter word after each block and overflowing into the second.
	The limits on the TLS plaintext size mean that the first counter word
	will never overflow in practice.
	The reason for generating the Poly1305 key like this rather than
	using key material from the handshake is that handshake key material
	is per-session, but for a polynomial MAC, a unique, secret key is
	needed per-record.
	The Poly1305 key is used to calculate a tag for the following input:
	the concatenation of the additional data, the number of bytes of
	additional data, the ciphertext and the number of bytes of
	ciphertext. Numbers are represented as 8-byte, little-endian values.
	The resulting tag is appended to the ciphertext, resulting in the
	output of the AEAD operation.
	Authenticated decryption is largely the reverse of the encryption
	process: generate one block of ChaCha20 keystream and use the first
	32 bytes as a Poly1305 key. Feed Poly1305 the additional data and
	ciphertext, with the length suffixing as described above. Verify, in
	constant time, that the calculated Poly1305 authenticator matches the
	final 16 bytes of the input. If not, the input can be rejected
	immediately. Otherwise, run ChaCha20, starting with a counter value
	of one, to decrypt the ciphertext.
	When used in TLS, the "record_iv_length" is zero and the nonce is the
	sequence number for the record, as an 8-byte, big-endian number. The
	additional data is seq_num + TLSCompressed.type +
	TLSCompressed.version + TLSCompressed.length, where "+" denotes
	concatenation.
	In DTLS, the nonce is formed as the concatenation of the 16-bit epoch
	with the 48-bit sequence number.
	In accordance with section 4 of RFC 5116 [RFC5116], the constants for
	this AEAD algorithm are as follows: K_LEN is 32 bytes, N_MIN and
	N_MAX are 8 bytes, P_MAX and A_MAX are 2^64, C_MAX is 2^64+16. An
	AEAD_CHACHA20_POLY1305 ciphertext is exactly 16 octets longer than
	its corresponding plaintext.
	Test vectors for this authenticator can be found in Appendix A.3.		When used in TLS, the "record_iv_length" is zero and the nonce is set
			to be the ChaChaNonce. The additional data is seq_num +
			TLSCompressed.type + TLSCompressed.version + TLSCompressed.length,
			where "+" denotes concatenation.
	The following CipherSuites are defined.		The following CipherSuites are defined.
	TLS_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x12}		TLS_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x13}		TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x14}		TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_DHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x15}		TLS_DHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_DHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x16}		TLS_DHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x17}		TLS_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x18}		TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_RSA_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x19}		TLS_RSA_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	5. Updates to the TLS Standard Stream Cipher		5. Updates to the TLS Standard Stream Cipher
	The ChaCha20 ciphersuites with HMAC-SHA1 defined in this document		The ChaCha20 ciphersuites with HMAC-SHA1 defined in this document
	differ from the TLS RC4 ciphersuites that have been the basis for the		differ from the TLS RC4 ciphersuites that have been the basis for the
	definition of Standard Stream Cipher. Unlike RC4, ChaCha20 requires		definition of Standard Stream Cipher. Unlike RC4, ChaCha20 requires
	a nonce per record. This however, does not affect the description of		a nonce per record. This however, does not affect the description of
	the Standard Stream Cipher if one assumes that a nonce is optional		the Standard Stream Cipher if one assumes that a nonce is optional
	and depends on the cipher's characteristics.		and depends on the cipher's characteristics.
	Hence, this document modifies the Standard Stream Cipher by adding an		Hence, this document modifies the Standard Stream Cipher by adding an
	implicit nonce of 8-bytes, which is set to be the 64-bit TLS record		implicit nonce. The implicit nonce may consist of
	sequence number. If the stream cipher needs more than 8 byte of
	nonce, it can obtain additional bytes for the implicit nonce from the		o an optional fixed component ("salt"), generated from the
	client_write_iv and server_write_iv of the key_block.		key_block;
			o a variable component, based on the 64-bit TLS record sequence
			number or the concatenation of the 16-bit epoch with the 48-bit
			sequence number in case of DTLS.
	Stream ciphers that don't require a nonce such as RC4 shall ignore		Stream ciphers that don't require a nonce such as RC4 shall ignore
	it. Other stream ciphers that require a nonce, such as ChaCha20 with		it. Other stream ciphers that require a nonce, such as ChaCha20 with
	HMAC-SHA1, will use the nonce and reset their state on each record.		HMAC-SHA1, will use the nonce and reset their state on each record.
	Note that in case of DTLS the 8-byte nonce is formed as the
	concatenation of the 16-bit epoch with the 48-bit sequence number,
	which are sent as part of the record.
	6. Updates to DTLS		6. Updates to DTLS
	The DTLS protocol requires the cipher in use to introduce no		The DTLS protocol requires the cipher in use to introduce no
	dependencies between TLS Records to allow lost or rearranged records.		dependencies between TLS Records to allow lost or rearranged records.
	For that it explicitly bans stream ciphers (see Section 3.1 of		For that it explicitly bans stream ciphers (see Section 3.1 of
	[RFC6347]).		[RFC6347]).
	As the stream cipher described in this document, unlike RC4, does not		As the stream cipher described in this document, unlike RC4, does not
	require dependencies between records, this ban of stream ciphers is		require dependencies between records, this ban of stream ciphers is
	lifted with this document. Stream ciphers can be used with DTLS if		lifted with this document. Stream ciphers can be used with DTLS if
	they introduce no dependencies between records.		they introduce no dependencies between records.
	7. Acknowledgements		7. Acknowledgements
	The authors would like to thank Zooko Wilcox-OHearn and Samuel Neves.		The authors would like to thank Zooko Wilcox-OHearn and Samuel Neves.
	8. IANA Considerations		8. IANA Considerations
	IANA is requested to assign a value for AEAD_CHACHA20_POLY1305 in the		IANA is requested to assign the following Cipher Suites in the TLS
	registry of AEAD algorithms [RFC5116], and also allocate the		Cipher Suite Registry:
	following Cipher Suites in the TLS Cipher Suite Registry (note that
	the third column contains the suggested ciphersuite numbers):
	TLS_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x12}		TLS_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x13}		TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x14}		TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_DHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x15}		TLS_DHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_DHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x16}		TLS_DHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x17}		TLS_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x18}		TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_RSA_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0x19}		TLS_RSA_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD}
	TLS_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x20}		TLS_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_ECDHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x21}		TLS_ECDHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_ECDHE_ECDSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x22}		TLS_ECDHE_ECDSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_DHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x23}		TLS_DHE_RSA_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_DHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x24}		TLS_DHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x25}		TLS_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_ECDHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x26}		TLS_ECDHE_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	TLS_RSA_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD} {0xCC, 0x27}		TLS_RSA_PSK_WITH_CHACHA20_SHA = {0xTBD, 0xTBD}
	9. Security Considerations		9. Security Considerations
	ChaCha20 follows the same basic principle as Salsa20, a cipher with		ChaCha20 follows the same basic principle as Salsa20, a cipher with
	significant security review [SALSA20-SECURITY][ESTREAM]. At the time		significant security review [SALSA20-SECURITY][ESTREAM]. At the time
	of writing this document, there are no known significant security		of writing this document, there are no known significant security
	problems with either cipher, and ChaCha20 is shown to be more		problems with either cipher, and ChaCha20 is shown to be more
	resistant in certain attacks than Salsa20 [SALSA20-ATTACK].		resistant in certain attacks than Salsa20 [SALSA20-ATTACK].
	Furthermore ChaCha20 was used as the core of the BLAKE hash function,		Furthermore ChaCha20 was used as the core of the BLAKE hash function,
	a SHA3 finalist, that had received considerable cryptanalytic		a SHA3 finalist, that had received considerable cryptanalytic
	skipping to change at page 14, line 29 ¶		skipping to change at page 12, line 29 ¶
	The cipher suites described in this document require that an nonce is		The cipher suites described in this document require that an nonce is
	never repeated under the same key. The design presented ensures that		never repeated under the same key. The design presented ensures that
	by using the TLS sequence number which is unique and does not wrap		by using the TLS sequence number which is unique and does not wrap
	[RFC5246].		[RFC5246].
	This document should not introduce any other security considerations		This document should not introduce any other security considerations
	than those that directly follow from the use of the stream cipher		than those that directly follow from the use of the stream cipher
	ChaCha20, the AEAD_CHACHA20_POLY1305 construction, and those that		ChaCha20, the AEAD_CHACHA20_POLY1305 construction, and those that
	directly follow from introducing any set of stream cipher suites into		directly follow from introducing any set of stream cipher suites into
	TLS and DTLS.		TLS and DTLS (see also the Security Considerations section of
			[I-D.nir-cfrg-chacha20-poly1305]).
	10. References		10. References
	10.1. Normative References		10.1. Normative References
	[RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",		[RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",
	RFC 2246, January 1999.		RFC 2246, January 1999.
	[RFC4346] Dierks, T. and E. Rescorla, "The Transport Layer Security		[RFC4346] Dierks, T. and E. Rescorla, "The Transport Layer Security
	(TLS) Protocol Version 1.1", RFC 4346, April 2006.		(TLS) Protocol Version 1.1", RFC 4346, April 2006.
	[RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer		[RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
	Security", RFC 4347, April 2006.		Security", RFC 4347, April 2006.
	[RFC4492] Blake-Wilson, S., Bolyard, N., Gupta, V., Hawk, C., and B.		[RFC4492] Blake-Wilson, S., Bolyard, N., Gupta, V., Hawk, C., and B.
	Moeller, "Elliptic Curve Cryptography (ECC) Cipher Suites		Moeller, "Elliptic Curve Cryptography (ECC) Cipher Suites
	for Transport Layer Security (TLS)", RFC 4492, May 2006.		for Transport Layer Security (TLS)", RFC 4492, May 2006.
	[RFC5116] McGrew, D., "An Interface and Algorithms for Authenticated
	Encryption", RFC 5116, January 2008.
	[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security		[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
	(TLS) Protocol Version 1.2", RFC 5246, August 2008.		(TLS) Protocol Version 1.2", RFC 5246, August 2008.
	[RFC5489] Badra, M. and I. Hajjeh, "ECDHE_PSK Cipher Suites for		[RFC5489] Badra, M. and I. Hajjeh, "ECDHE_PSK Cipher Suites for
	Transport Layer Security (TLS)", RFC 5489, March 2009.		Transport Layer Security (TLS)", RFC 5489, March 2009.
	[RFC6234] Eastlake, D. and T. Hansen, "US Secure Hash Algorithms		[RFC6234] Eastlake, D. and T. Hansen, "US Secure Hash Algorithms
	(SHA and SHA-based HMAC and HKDF)", RFC 6234, May 2011.		(SHA and SHA-based HMAC and HKDF)", RFC 6234, May 2011.
	[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer		[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
	Security Version 1.2", RFC 6347, January 2012.		Security Version 1.2", RFC 6347, January 2012.
			[I-D.nir-cfrg-chacha20-poly1305]
			Nir, Y. and A. Langley, "ChaCha20 and Poly1305 for IETF
			protocols", draft-nir-cfrg-chacha20-poly1305-01 (work in
			progress), January 2014.
			10.2. Informative References
	[CHACHA] Bernstein, D., "ChaCha, a variant of Salsa20",		[CHACHA] Bernstein, D., "ChaCha, a variant of Salsa20",
	January 2008,		January 2008,
	<http://cr.yp.to/chacha/chacha-20080128.pdf>.		<http://cr.yp.to/chacha/chacha-20080128.pdf>.
	[POLY1305]		[POLY1305]
	Bernstein, D., "The Poly1305-AES message-authentication		Bernstein, D., "The Poly1305-AES message-authentication
	code.", March 2005,		code.", March 2005,
	<http://cr.yp.to/mac/poly1305-20050329.pdf>.		<http://cr.yp.to/mac/poly1305-20050329.pdf>.
	10.2. Informative References		[RFC5116] McGrew, D., "An Interface and Algorithms for Authenticated
			Encryption", RFC 5116, January 2008.
	[SALSA20SPEC]		[SALSA20SPEC]
	Bernstein, D., "Salsa20 specification", April 2005,		Bernstein, D., "Salsa20 specification", April 2005,
	<http://cr.yp.to/snuffle/spec.pdf>.		<http://cr.yp.to/snuffle/spec.pdf>.
	[RFC6101] Freier, A., Karlton, P., and P. Kocher, "The Secure		[RFC6101] Freier, A., Karlton, P., and P. Kocher, "The Secure
	Sockets Layer (SSL) Protocol Version 3.0", RFC 6101,		Sockets Layer (SSL) Protocol Version 3.0", RFC 6101,
	August 2011.		August 2011.
	[SALSA20-SECURITY]		[SALSA20-SECURITY]
	skipping to change at page 16, line 33 ¶		skipping to change at page 14, line 39 ¶
	Isobe, T., Ohigashi, T., Watanabe, Y., and M. Morii, "Full		Isobe, T., Ohigashi, T., Watanabe, Y., and M. Morii, "Full
	Plaintext Recovery Attack on Broadcast RC4", International		Plaintext Recovery Attack on Broadcast RC4", International
	Workshop on Fast Software Encryption , 2013.		Workshop on Fast Software Encryption , 2013.
	[SALSA20-ATTACK]		[SALSA20-ATTACK]
	Aumasson, J-P., Fischer, S., Khazaei, S., Meier, W., and		Aumasson, J-P., Fischer, S., Khazaei, S., Meier, W., and
	C. Rechberger, "New Features of Latin Dances: Analysis of		C. Rechberger, "New Features of Latin Dances: Analysis of
	Salsa, ChaCha, and Rumba", 2007,		Salsa, ChaCha, and Rumba", 2007,
	<http://eprint.iacr.org/2007/472.pdf>.		<http://eprint.iacr.org/2007/472.pdf>.
	[NACLCRYPTO]
	Bernstein, D., "Cryptography in NaCl", March 2009,
	<http://cr.yp.to/highspeed/naclcrypto-20090310.pdf>.
	[NIST-SHA3]		[NIST-SHA3]
	Chang, S., Burr, W., Kelsey, J., Paul, S., and L. Bassham,		Chang, S., Burr, W., Kelsey, J., Paul, S., and L. Bassham,
	"Third-Round Report of the SHA-3 Cryptographic Hash		"Third-Round Report of the SHA-3 Cryptographic Hash
	Algorithm Competition", 2012,		Algorithm Competition", 2012,
	<http://dx.doi.org/10.6028/NIST.IR.7896>.		<http://dx.doi.org/10.6028/NIST.IR.7896>.
	Appendix A. Test vectors
	A.1. ChaCha20
	The following blocks contain test vectors for ChaCha20. The first
	line contains the 256-bit key, the second the 64-bit nonce and the
	last line contains a prefix of the resulting ChaCha20 key-stream.
	KEY: 00000000000000000000000000000000000000000000000000000000
	00000000
	NONCE: 0000000000000000
	KEYSTREAM: 76b8e0ada0f13d90405d6ae55386bd28bdd219b8a08ded1aa836efcc
	8b770dc7da41597c5157488d7724e03fb8d84a376a43b8f41518a11c
	c387b669b2ee6586
	KEY: 00000000000000000000000000000000000000000000000000000000
	00000001
	NONCE: 0000000000000000
	KEYSTREAM: 4540f05a9f1fb296d7736e7b208e3c96eb4fe1834688d2604f450952
	ed432d41bbe2a0b6ea7566d2a5d1e7e20d42af2c53d792b1c43fea81
	7e9ad275ae546963
	KEY: 00000000000000000000000000000000000000000000000000000000
	00000000
	NONCE: 0000000000000001
	KEYSTREAM: de9cba7bf3d69ef5e786dc63973f653a0b49e015adbff7134fcb7df1
	37821031e85a050278a7084527214f73efc7fa5b5277062eb7a0433e
	445f41e3
	KEY: 00000000000000000000000000000000000000000000000000000000
	00000000
	NONCE: 0100000000000000
	KEYSTREAM: ef3fdfd6c61578fbf5cf35bd3dd33b8009631634d21e42ac33960bd1
	38e50d32111e4caf237ee53ca8ad6426194a88545ddc497a0b466e7d
	6bbdb0041b2f586b
	KEY: 000102030405060708090a0b0c0d0e0f101112131415161718191a1b
	1c1d1e1f
	NONCE: 0001020304050607
	KEYSTREAM: f798a189f195e66982105ffb640bb7757f579da31602fc93ec01ac56
	f85ac3c134a4547b733b46413042c9440049176905d3be59ea1c53f1
	5916155c2be8241a38008b9a26bc35941e2444177c8ade6689de9526
	4986d95889fb60e84629c9bd9a5acb1cc118be563eb9b3a4a472f82e
	09a7e778492b562ef7130e88dfe031c79db9d4f7c7a899151b9a4750
	32b63fc385245fe054e3dd5a97a5f576fe064025d3ce042c566ab2c5
	07b138db853e3d6959660996546cc9c4a6eafdc777c040d70eaf46f7
	6dad3979e5c5360c3317166a1c894c94a371876a94df7628fe4eaaf2
	ccb27d5aaae0ad7ad0f9d4b6ad3b54098746d4524d38407a6deb3ab7
	8fab78c9
	A.2. Poly1305
	The following blocks contain test vectors for Poly1305. The first
	line contains a variable length input. The second contains the 256-
	bit key and the last contains the resulting, 128-bit tag.
	INPUT: 000000000000000000000000000000000000000000000000000000000000
	0000
	KEY: 746869732069732033322d62797465206b657920666f7220506f6c793133
	3035
	TAG: 49ec78090e481ec6c26b33b91ccc0307
	INPUT: 48656c6c6f20776f726c6421
	KEY: 746869732069732033322d62797465206b657920666f7220506f6c793133
	3035
	TAG: a6f745008f81c916a20dcc74eef2b2f0
	A.3. AEAD_CHACHA20_POLY1305
	The following block contains a test vector for the
	AEAD_CHACHA20_POLY1305 algorithm. The first four lines consist of
	the standard inputs to an AEAD algorithm and the last line contains
	the encrypted and authenticated result.
	KEY: 4290bcb154173531f314af57f3be3b5006da371ece272afa1b5dbdd110
	0a1007
	INPUT: 86d09974840bded2a5ca
	NONCE: cd7cf67be39c794a
	AD: 87e229d4500845a079c0
	OUTPUT: e3e446f7ede9a19b62a4677dabf4e3d24b876bb284753896e1d6
	To aid implementations, the next block contains some intermediate
	values in the AEAD_CHACHA20_POLY1305 algorithm. The first line
	contains the Poly1305 key that is derived and the second contains the
	raw bytes that are authenticated by Poly1305.
	KEY: 9052a6335505b6d507341169783dccac0e26f84ea84906b1558c05bf4815
	0fbe
	INPUT: 87e229d4500845a079c00a00000000000000e3e446f7ede9a19b62a40a00
	000000000000
	Authors' Addresses		Authors' Addresses
	Adam Langley		Adam Langley
	Google Inc		Google Inc
	Email: agl@google.com		Email: agl@google.com
	Wan-Teh Chang		Wan-Teh Chang
	Google Inc		Google Inc
End of changes. 32 change blocks.
	305 lines changed or deleted		108 lines changed or added
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