[16800] | 1 | /* |
---|
| 2 | * Copyright (c) 2001 Markus Friedl. All rights reserved. |
---|
| 3 | * |
---|
| 4 | * Redistribution and use in source and binary forms, with or without |
---|
| 5 | * modification, are permitted provided that the following conditions |
---|
| 6 | * are met: |
---|
| 7 | * 1. Redistributions of source code must retain the above copyright |
---|
| 8 | * notice, this list of conditions and the following disclaimer. |
---|
| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
---|
| 10 | * notice, this list of conditions and the following disclaimer in the |
---|
| 11 | * documentation and/or other materials provided with the distribution. |
---|
| 12 | * |
---|
| 13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
---|
| 14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
---|
| 15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
---|
| 16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
---|
| 17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
---|
| 18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
---|
| 19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
---|
| 20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
---|
| 21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
---|
| 22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
---|
| 23 | */ |
---|
| 24 | |
---|
| 25 | #include "includes.h" |
---|
| 26 | RCSID("$OpenBSD: mac.c,v 1.2 2001/04/05 10:42:51 markus Exp $"); |
---|
| 27 | |
---|
| 28 | #include <openssl/hmac.h> |
---|
| 29 | |
---|
| 30 | #include "xmalloc.h" |
---|
| 31 | #include "getput.h" |
---|
| 32 | #include "log.h" |
---|
| 33 | #include "cipher.h" |
---|
| 34 | #include "kex.h" |
---|
| 35 | #include "mac.h" |
---|
| 36 | |
---|
| 37 | struct { |
---|
| 38 | char *name; |
---|
| 39 | EVP_MD * (*mdfunc)(void); |
---|
| 40 | int truncatebits; /* truncate digest if != 0 */ |
---|
| 41 | } macs[] = { |
---|
| 42 | { "hmac-sha1", EVP_sha1, 0, }, |
---|
| 43 | { "hmac-sha1-96", EVP_sha1, 96 }, |
---|
| 44 | { "hmac-md5", EVP_md5, 0 }, |
---|
| 45 | { "hmac-md5-96", EVP_md5, 96 }, |
---|
| 46 | { "hmac-ripemd160", EVP_ripemd160, 0 }, |
---|
| 47 | { "hmac-ripemd160@openssh.com", EVP_ripemd160, 0 }, |
---|
| 48 | { NULL, NULL, 0 } |
---|
| 49 | }; |
---|
| 50 | |
---|
| 51 | int |
---|
| 52 | mac_init(Mac *mac, char *name) |
---|
| 53 | { |
---|
| 54 | int i; |
---|
| 55 | for (i = 0; macs[i].name; i++) { |
---|
| 56 | if (strcmp(name, macs[i].name) == 0) { |
---|
| 57 | if (mac != NULL) { |
---|
| 58 | mac->md = (*macs[i].mdfunc)(); |
---|
| 59 | mac->key_len = mac->mac_len = mac->md->md_size; |
---|
| 60 | if (macs[i].truncatebits != 0) |
---|
| 61 | mac->mac_len = macs[i].truncatebits/8; |
---|
| 62 | } |
---|
| 63 | debug2("mac_init: found %s", name); |
---|
| 64 | return (0); |
---|
| 65 | } |
---|
| 66 | } |
---|
| 67 | debug2("mac_init: unknown %s", name); |
---|
| 68 | return (-1); |
---|
| 69 | } |
---|
| 70 | |
---|
| 71 | u_char * |
---|
| 72 | mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen) |
---|
| 73 | { |
---|
| 74 | HMAC_CTX c; |
---|
| 75 | static u_char m[EVP_MAX_MD_SIZE]; |
---|
| 76 | u_char b[4]; |
---|
| 77 | |
---|
| 78 | if (mac->key == NULL) |
---|
| 79 | fatal("mac_compute: no key"); |
---|
| 80 | if (mac->mac_len > sizeof(m)) |
---|
| 81 | fatal("mac_compute: mac too long"); |
---|
| 82 | HMAC_Init(&c, mac->key, mac->key_len, mac->md); |
---|
| 83 | PUT_32BIT(b, seqno); |
---|
| 84 | HMAC_Update(&c, b, sizeof(b)); |
---|
| 85 | HMAC_Update(&c, data, datalen); |
---|
| 86 | HMAC_Final(&c, m, NULL); |
---|
| 87 | HMAC_cleanup(&c); |
---|
| 88 | return (m); |
---|
| 89 | } |
---|
| 90 | |
---|
| 91 | /* XXX copied from ciphers_valid */ |
---|
| 92 | #define MAC_SEP "," |
---|
| 93 | int |
---|
| 94 | mac_valid(const char *names) |
---|
| 95 | { |
---|
| 96 | char *maclist, *cp, *p; |
---|
| 97 | |
---|
| 98 | if (names == NULL || strcmp(names, "") == 0) |
---|
| 99 | return (0); |
---|
| 100 | maclist = cp = xstrdup(names); |
---|
| 101 | for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0'; |
---|
| 102 | (p = strsep(&cp, MAC_SEP))) { |
---|
| 103 | if (mac_init(NULL, p) < 0) { |
---|
| 104 | debug("bad mac %s [%s]", p, names); |
---|
| 105 | xfree(maclist); |
---|
| 106 | return (0); |
---|
| 107 | } else { |
---|
| 108 | debug3("mac ok: %s [%s]", p, names); |
---|
| 109 | } |
---|
| 110 | } |
---|
| 111 | debug3("macs ok: [%s]", names); |
---|
| 112 | xfree(maclist); |
---|
| 113 | return (1); |
---|
| 114 | } |
---|