diff options
Diffstat (limited to 'crypto/openssh/mac.c')
| -rw-r--r-- | crypto/openssh/mac.c | 127 |
1 files changed, 95 insertions, 32 deletions
diff --git a/crypto/openssh/mac.c b/crypto/openssh/mac.c index e5d5bfa..fabc3ed 100644 --- a/crypto/openssh/mac.c +++ b/crypto/openssh/mac.c @@ -1,4 +1,4 @@ -/* $OpenBSD: mac.c,v 1.12 2006/08/03 03:34:42 deraadt Exp $ */ +/* $OpenBSD: mac.c,v 1.15 2008/06/13 00:51:47 dtucker Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * @@ -42,63 +42,126 @@ #include "mac.h" #include "misc.h" +#include "umac.h" + +#define SSH_EVP 1 /* OpenSSL EVP-based MAC */ +#define SSH_UMAC 2 /* UMAC (not integrated with OpenSSL) */ + struct { char *name; + int type; const EVP_MD * (*mdfunc)(void); int truncatebits; /* truncate digest if != 0 */ + int key_len; /* just for UMAC */ + int len; /* just for UMAC */ } macs[] = { - { "hmac-sha1", EVP_sha1, 0, }, - { "hmac-sha1-96", EVP_sha1, 96 }, - { "hmac-md5", EVP_md5, 0 }, - { "hmac-md5-96", EVP_md5, 96 }, - { "hmac-ripemd160", EVP_ripemd160, 0 }, - { "hmac-ripemd160@openssh.com", EVP_ripemd160, 0 }, - { NULL, NULL, 0 } + { "hmac-sha1", SSH_EVP, EVP_sha1, 0, -1, -1 }, + { "hmac-sha1-96", SSH_EVP, EVP_sha1, 96, -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 }, + { NULL, 0, NULL, 0, -1, -1 } }; +static void +mac_setup_by_id(Mac *mac, int which) +{ + int evp_len; + mac->type = macs[which].type; + if (mac->type == SSH_EVP) { + mac->evp_md = (*macs[which].mdfunc)(); + if ((evp_len = EVP_MD_size(mac->evp_md)) <= 0) + fatal("mac %s len %d", mac->name, evp_len); + mac->key_len = mac->mac_len = (u_int)evp_len; + } else { + mac->mac_len = macs[which].len / 8; + mac->key_len = macs[which].key_len / 8; + mac->umac_ctx = NULL; + } + if (macs[which].truncatebits != 0) + mac->mac_len = macs[which].truncatebits / 8; +} + int -mac_init(Mac *mac, char *name) +mac_setup(Mac *mac, char *name) { - int i, evp_len; + int i; for (i = 0; macs[i].name; i++) { if (strcmp(name, macs[i].name) == 0) { - if (mac != NULL) { - mac->md = (*macs[i].mdfunc)(); - if ((evp_len = EVP_MD_size(mac->md)) <= 0) - fatal("mac %s len %d", name, evp_len); - mac->key_len = mac->mac_len = (u_int)evp_len; - if (macs[i].truncatebits != 0) - mac->mac_len = macs[i].truncatebits/8; - } - debug2("mac_init: found %s", name); + if (mac != NULL) + mac_setup_by_id(mac, i); + debug2("mac_setup: found %s", name); return (0); } } - debug2("mac_init: unknown %s", name); + debug2("mac_setup: unknown %s", name); return (-1); } +int +mac_init(Mac *mac) +{ + if (mac->key == NULL) + fatal("mac_init: no key"); + switch (mac->type) { + case SSH_EVP: + if (mac->evp_md == NULL) + return -1; + HMAC_Init(&mac->evp_ctx, mac->key, mac->key_len, mac->evp_md); + return 0; + case SSH_UMAC: + mac->umac_ctx = umac_new(mac->key); + return 0; + default: + return -1; + } +} + u_char * mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen) { - HMAC_CTX c; static u_char m[EVP_MAX_MD_SIZE]; - u_char b[4]; + u_char b[4], nonce[8]; - if (mac->key == NULL) - fatal("mac_compute: no key"); if (mac->mac_len > sizeof(m)) - fatal("mac_compute: mac too long"); - HMAC_Init(&c, mac->key, mac->key_len, mac->md); - put_u32(b, seqno); - HMAC_Update(&c, b, sizeof(b)); - HMAC_Update(&c, data, datalen); - HMAC_Final(&c, m, NULL); - HMAC_cleanup(&c); + fatal("mac_compute: mac too long %u %lu", + mac->mac_len, (u_long)sizeof(m)); + + switch (mac->type) { + case SSH_EVP: + put_u32(b, seqno); + /* reset HMAC context */ + HMAC_Init(&mac->evp_ctx, NULL, 0, NULL); + HMAC_Update(&mac->evp_ctx, b, sizeof(b)); + HMAC_Update(&mac->evp_ctx, data, datalen); + HMAC_Final(&mac->evp_ctx, m, NULL); + break; + case SSH_UMAC: + put_u64(nonce, seqno); + umac_update(mac->umac_ctx, data, datalen); + umac_final(mac->umac_ctx, m, nonce); + break; + default: + fatal("mac_compute: unknown MAC type"); + } return (m); } +void +mac_clear(Mac *mac) +{ + if (mac->type == SSH_UMAC) { + if (mac->umac_ctx != NULL) + umac_delete(mac->umac_ctx); + } else if (mac->evp_md != NULL) + HMAC_cleanup(&mac->evp_ctx); + mac->evp_md = NULL; + mac->umac_ctx = NULL; +} + /* XXX copied from ciphers_valid */ #define MAC_SEP "," int @@ -111,7 +174,7 @@ mac_valid(const char *names) maclist = cp = xstrdup(names); for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0'; (p = strsep(&cp, MAC_SEP))) { - if (mac_init(NULL, p) < 0) { + if (mac_setup(NULL, p) < 0) { debug("bad mac %s [%s]", p, names); xfree(maclist); return (0); |
