4 ms·

Has this been standardized yet? The latest draft I can find still has a bunch of 0xTBD values for the cipher suite numbers. https://datatracker.ietf.org/doc/dr

by tveita 11y ago

Has this been standardized yet? The latest draft I can find still has a bunch of 0xTBD values for the cipher suite numbers. https://datatracker.ietf.org/doc/draft-ietf-tls-chacha20-poly1305/03/ https://datatracker.ietf.org/doc/draft-ietf-tls-chacha20-pol...

lorenzhs 11y ago
Well, the submission literally begins with the words "ChaCha20-Poly1305 is modern, high performance cipher working in AEAD mode. It was standardized recently as RFC 7539." https://tools.ietf.org/html/rfc7539 https://tools.ietf.org/html/rfc7539
- tveita 11y ago
  RFC 7539 documents the cipher itself. It's mostly just enshrining the existing specification as an RFC, except for changing the size of the nonce and block count to meet recommended nonce sizes. There are some additional details required to use the cipher for TLS. In particular the new modes must be assigned entries in the TLS Cipher Suite Registry, which contain the official names and the numeric values used in the wire protocol. The current draft also specifies how to construct the nonce from the record sequence number and a shared secret, to avoid having to send a nonce with each record.
  - lorenzhs 11y ago
    Ah, you meant standardization for use in TLS? I thought you were referring to the specification of the cipher. Sorry.
colmmacc 11y ago
IANA will officially assign numbers once the I-D has progressed to standard status. They'll show up here: http://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4 http://www.iana.org/assignments/tls-parameters/tls-parameter... In the mean time, the I-D does contain the requested values in section 3: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xA8} TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xA9} TLS_DHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAA} TLS_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAB} TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAC} TLS_DHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAD} TLS_RSA_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAE} (the ones in the latter brackets) and IANA is very likely to use those. There's always a bit of a chicken and egg race condition here, usually resolved with a friendly mail to the IANA administrator.
xemdetia 11y ago
While not standardized the amount of people who have been trying to patch openssl to do chacha right now almost makes it a defacto standard. Much of this comes from cloudflare, and I just would warn people about that patch right now. It kind of patches openssl in a weird way. I say that as someone who is resident on ##openssl and have seen many people try and run into issues.

by tveita 11y ago

lorenzhs 11y ago

Well, the submission literally begins with the words "ChaCha20-Poly1305 is modern, high performance cipher working in AEAD mode. It was standardized recently as RFC 7539." https://tools.ietf.org/html/rfc7539 https://tools.ietf.org/html/rfc7539

tveita 11y ago
RFC 7539 documents the cipher itself. It's mostly just enshrining the existing specification as an RFC, except for changing the size of the nonce and block count to meet recommended nonce sizes. There are some additional details required to use the cipher for TLS. In particular the new modes must be assigned entries in the TLS Cipher Suite Registry, which contain the official names and the numeric values used in the wire protocol. The current draft also specifies how to construct the nonce from the record sequence number and a shared secret, to avoid having to send a nonce with each record.
- lorenzhs 11y ago
  Ah, you meant standardization for use in TLS? I thought you were referring to the specification of the cipher. Sorry.

colmmacc 11y ago

IANA will officially assign numbers once the I-D has progressed to standard status. They'll show up here: http://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4 http://www.iana.org/assignments/tls-parameters/tls-parameter... In the mean time, the I-D does contain the requested values in section 3: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xA8} TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xA9} TLS_DHE_RSA_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAA} TLS_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAB} TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAC} TLS_DHE_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAD} TLS_RSA_PSK_WITH_CHACHA20_POLY1305 = {0xTBD, 0xTBD} {0xCC, 0xAE} (the ones in the latter brackets) and IANA is very likely to use those. There's always a bit of a chicken and egg race condition here, usually resolved with a friendly mail to the IANA administrator.

xemdetia 11y ago

While not standardized the amount of people who have been trying to patch openssl to do chacha right now almost makes it a defacto standard. Much of this comes from cloudflare, and I just would warn people about that patch right now. It kind of patches openssl in a weird way. I say that as someone who is resident on ##openssl and have seen many people try and run into issues.