1 /* 2 * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 /* 6 * Copyright (c) 2001 Markus Friedl. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include "includes.h" 30 RCSID("$OpenBSD: mac.c,v 1.5 2002/05/16 22:02:50 markus Exp $"); 31 32 #pragma ident "%Z%%M% %I% %E% SMI" 33 34 #include <openssl/hmac.h> 35 36 #include "xmalloc.h" 37 #include "getput.h" 38 #include "log.h" 39 #include "cipher.h" 40 #include "kex.h" 41 #include "mac.h" 42 43 struct { 44 char *name; 45 const EVP_MD * (*mdfunc)(void); 46 int truncatebits; /* truncate digest if != 0 */ 47 } macs[] = { 48 { "hmac-sha1", EVP_sha1, 0 }, 49 { "hmac-sha1-96", EVP_sha1, 96 }, 50 { "hmac-md5", EVP_md5, 0 }, 51 { "hmac-md5-96", EVP_md5, 96 }, 52 #ifdef SOLARIS_SSH_ENABLE_RIPEMD160 53 { "hmac-ripemd160", EVP_ripemd160, 0 }, 54 { "hmac-ripemd160@openssh.com", EVP_ripemd160, 0 }, 55 #endif /* SOLARIS_SSH_ENABLE_RIPEMD160 */ 56 { NULL, NULL, 0 } 57 }; 58 59 int 60 mac_init(Mac *mac, char *name) 61 { 62 int i; 63 for (i = 0; macs[i].name; i++) { 64 if (strcmp(name, macs[i].name) == 0) { 65 if (mac != NULL) { 66 mac->md = (*macs[i].mdfunc)(); 67 mac->key_len = mac->mac_len = EVP_MD_size(mac->md); 68 if (macs[i].truncatebits != 0) 69 mac->mac_len = macs[i].truncatebits/8; 70 } 71 debug2("mac_init: found %s", name); 72 return (0); 73 } 74 } 75 debug2("mac_init: unknown %s", name); 76 return (-1); 77 } 78 79 u_char * 80 mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen) 81 { 82 HMAC_CTX c; 83 static u_char m[EVP_MAX_MD_SIZE]; 84 u_char b[4]; 85 86 if (mac->key == NULL) 87 fatal("mac_compute: no key"); 88 if (mac->mac_len > sizeof(m)) 89 fatal("mac_compute: mac too long"); 90 HMAC_Init(&c, mac->key, mac->key_len, mac->md); 91 PUT_32BIT(b, seqno); 92 HMAC_Update(&c, b, sizeof(b)); 93 HMAC_Update(&c, data, datalen); 94 HMAC_Final(&c, m, NULL); 95 HMAC_cleanup(&c); 96 return (m); 97 } 98 99 /* XXX copied from ciphers_valid */ 100 #define MAC_SEP "," 101 int 102 mac_valid(const char *names) 103 { 104 char *maclist, *cp, *p; 105 106 if (names == NULL || strcmp(names, "") == 0) 107 return (0); 108 maclist = cp = xstrdup(names); 109 for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0'; 110 (p = strsep(&cp, MAC_SEP))) { 111 if (mac_init(NULL, p) < 0) { 112 debug("bad mac %s [%s]", p, names); 113 xfree(maclist); 114 return (0); 115 } else { 116 debug3("mac ok: %s [%s]", p, names); 117 } 118 } 119 debug3("macs ok: [%s]", names); 120 xfree(maclist); 121 return (1); 122 } 123