diff options
| author |   markus <markus@openbsd.org> | 2012-12-11 22:31:18 +0000 |
|---|---|---|
| committer | markus <markus@openbsd.org> | 2012-12-11 22:31:18 +0000 |
| commit | c2ea1f0ae6238b8053302c71a1857e7d8cd648e9 (patch) | |
| tree | 7fe97b78b08b3d6e6d3d1979877c151c948285a4 /usr.bin/ssh/mac.c | |
| parent | drain the log messages after receiving the keystate from the unpriv (diff) | |
| download | wireguard-openbsd-c2ea1f0ae6238b8053302c71a1857e7d8cd648e9.tar.xz wireguard-openbsd-c2ea1f0ae6238b8053302c71a1857e7d8cd648e9.zip | |
add encrypt-then-mac (EtM) modes to openssh by defining new mac algorithms
that change the packet format and compute the MAC over the encrypted
message (including the packet size) instead of the plaintext data;
these EtM modes are considered more secure and used by default.
feedback and ok djm@
Diffstat (limited to 'usr.bin/ssh/mac.c')
| -rw-r--r-- | usr.bin/ssh/mac.c | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/usr.bin/ssh/mac.c b/usr.bin/ssh/mac.c index 80b01d8a9bc..27f59a3d6c5 100644 --- a/usr.bin/ssh/mac.c +++ b/usr.bin/ssh/mac.c @@ -1,4 +1,4 @@ -/* $OpenBSD: mac.c,v 1.19 2012/10/04 13:21:50 markus Exp $ */ +/* $OpenBSD: mac.c,v 1.20 2012/12/11 22:31:18 markus Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * @@ -52,18 +52,32 @@ struct { int truncatebits; /* truncate digest if != 0 */ int key_len; /* just for UMAC */ int len; /* just for UMAC */ + int etm; /* Encrypt-then-MAC */ } macs[] = { - { "hmac-sha1", SSH_EVP, EVP_sha1, 0, -1, -1 }, - { "hmac-sha1-96", SSH_EVP, EVP_sha1, 96, -1, -1 }, - { "hmac-sha2-256", SSH_EVP, EVP_sha256, 0, -1, -1 }, - { "hmac-sha2-512", SSH_EVP, EVP_sha512, 0, -1, -1 }, - { "hmac-md5", SSH_EVP, EVP_md5, 0, -1, -1 }, - { "hmac-md5-96", SSH_EVP, EVP_md5, 96, -1, -1 }, - { "hmac-ripemd160", SSH_EVP, EVP_ripemd160, 0, -1, -1 }, - { "hmac-ripemd160@openssh.com", SSH_EVP, EVP_ripemd160, 0, -1, -1 }, - { "umac-64@openssh.com", SSH_UMAC, NULL, 0, 128, 64 }, - { "umac-128@openssh.com", SSH_UMAC128, NULL, 0, 128, 128 }, - { NULL, 0, NULL, 0, -1, -1 } + /* Encrypt-and-MAC (encrypt-and-authenticate) variants */ + { "hmac-sha1", SSH_EVP, EVP_sha1, 0, 0, 0, 0 }, + { "hmac-sha1-96", SSH_EVP, EVP_sha1, 96, 0, 0, 0 }, + { "hmac-sha2-256", SSH_EVP, EVP_sha256, 0, 0, 0, 0 }, + { "hmac-sha2-512", SSH_EVP, EVP_sha512, 0, 0, 0, 0 }, + { "hmac-md5", SSH_EVP, EVP_md5, 0, 0, 0, 0 }, + { "hmac-md5-96", SSH_EVP, EVP_md5, 96, 0, 0, 0 }, + { "hmac-ripemd160", SSH_EVP, EVP_ripemd160, 0, 0, 0, 0 }, + { "hmac-ripemd160@openssh.com", SSH_EVP, EVP_ripemd160, 0, 0, 0, 0 }, + { "umac-64@openssh.com", SSH_UMAC, NULL, 0, 128, 64, 0 }, + { "umac-128@openssh.com", SSH_UMAC128, NULL, 0, 128, 128, 0 }, + + /* Encrypt-then-MAC variants */ + { "hmac-sha1-etm@openssh.com", SSH_EVP, EVP_sha1, 0, 0, 0, 1 }, + { "hmac-sha1-96-etm@openssh.com", SSH_EVP, EVP_sha1, 96, 0, 0, 1 }, + { "hmac-sha2-256-etm@openssh.com", SSH_EVP, EVP_sha256, 0, 0, 0, 1 }, + { "hmac-sha2-512-etm@openssh.com", SSH_EVP, EVP_sha512, 0, 0, 0, 1 }, + { "hmac-md5-etm@openssh.com", SSH_EVP, EVP_md5, 0, 0, 0, 1 }, + { "hmac-md5-96-etm@openssh.com", SSH_EVP, EVP_md5, 96, 0, 0, 1 }, + { "hmac-ripemd160-tem@openssh.com", SSH_EVP, EVP_ripemd160, 0, 0, 0, 1 }, + { "umac-64-etm@openssh.com", SSH_UMAC, NULL, 0, 128, 64, 1 }, + { "umac-128-etm@openssh.com", SSH_UMAC128, NULL, 0, 128, 128, 1 }, + + { NULL, 0, NULL, 0, 0, 0, 0 } }; static void @@ -83,6 +97,7 @@ mac_setup_by_id(Mac *mac, int which) } if (macs[which].truncatebits != 0) mac->mac_len = macs[which].truncatebits / 8; + mac->etm = macs[which].etm; } int |