1 /* $OpenBSD: hm_ameth.c,v 1.19 2022/11/26 16:08:53 tb Exp $ */ 2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 3 * project 2007. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2007 The OpenSSL Project. 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 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 #include <limits.h> 60 #include <stdio.h> 61 #include <string.h> 62 63 #include <openssl/evp.h> 64 #include <openssl/hmac.h> 65 66 #include "asn1_local.h" 67 #include "bytestring.h" 68 #include "evp_local.h" 69 #include "hmac_local.h" 70 71 static int 72 hmac_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b) 73 { 74 /* The ameth pub_cmp must return 1 on match, 0 on mismatch. */ 75 return ASN1_OCTET_STRING_cmp(a->pkey.ptr, b->pkey.ptr) == 0; 76 } 77 78 static int 79 hmac_size(const EVP_PKEY *pkey) 80 { 81 return EVP_MAX_MD_SIZE; 82 } 83 84 static void 85 hmac_key_free(EVP_PKEY *pkey) 86 { 87 ASN1_OCTET_STRING *os; 88 89 if ((os = pkey->pkey.ptr) == NULL) 90 return; 91 92 if (os->data != NULL) 93 explicit_bzero(os->data, os->length); 94 95 ASN1_OCTET_STRING_free(os); 96 } 97 98 static int 99 hmac_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2) 100 { 101 switch (op) { 102 case ASN1_PKEY_CTRL_DEFAULT_MD_NID: 103 *(int *)arg2 = NID_sha1; 104 return 1; 105 default: 106 return -2; 107 } 108 } 109 110 static int 111 hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv, size_t len) 112 { 113 ASN1_OCTET_STRING *os = NULL; 114 115 if (pkey->pkey.ptr != NULL) 116 goto err; 117 118 if (len > INT_MAX) 119 goto err; 120 121 if ((os = ASN1_OCTET_STRING_new()) == NULL) 122 goto err; 123 124 if (!ASN1_OCTET_STRING_set(os, priv, len)) 125 goto err; 126 127 pkey->pkey.ptr = os; 128 129 return 1; 130 131 err: 132 ASN1_OCTET_STRING_free(os); 133 134 return 0; 135 } 136 137 static int 138 hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv, size_t *len) 139 { 140 ASN1_OCTET_STRING *os; 141 CBS cbs; 142 143 if ((os = pkey->pkey.ptr) == NULL) 144 return 0; 145 146 if (priv == NULL) { 147 *len = os->length; 148 return 1; 149 } 150 151 CBS_init(&cbs, os->data, os->length); 152 return CBS_write_bytes(&cbs, priv, *len, len); 153 } 154 155 const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = { 156 .pkey_id = EVP_PKEY_HMAC, 157 .pkey_base_id = EVP_PKEY_HMAC, 158 159 .pem_str = "HMAC", 160 .info = "OpenSSL HMAC method", 161 162 .pub_cmp = hmac_pkey_public_cmp, 163 164 .pkey_size = hmac_size, 165 166 .pkey_free = hmac_key_free, 167 .pkey_ctrl = hmac_pkey_ctrl, 168 169 .set_priv_key = hmac_set_priv_key, 170 .get_priv_key = hmac_get_priv_key, 171 }; 172