1 /* 2 * Copyright (c) 2015, ARM Limited and Contributors. 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 are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <stdio.h> 32 #include <stdlib.h> 33 #include <string.h> 34 35 #include <openssl/conf.h> 36 #include <openssl/err.h> 37 #include <openssl/pem.h> 38 #include <openssl/sha.h> 39 #include <openssl/x509v3.h> 40 41 #include "cert.h" 42 #include "debug.h" 43 #include "key.h" 44 #include "platform_oid.h" 45 #include "sha.h" 46 47 #define SERIAL_RAND_BITS 64 48 49 int rand_serial(BIGNUM *b, ASN1_INTEGER *ai) 50 { 51 BIGNUM *btmp; 52 int ret = 0; 53 if (b) 54 btmp = b; 55 else 56 btmp = BN_new(); 57 58 if (!btmp) 59 return 0; 60 61 if (!BN_pseudo_rand(btmp, SERIAL_RAND_BITS, 0, 0)) 62 goto error; 63 if (ai && !BN_to_ASN1_INTEGER(btmp, ai)) 64 goto error; 65 66 ret = 1; 67 68 error: 69 70 if (!b) 71 BN_free(btmp); 72 73 return ret; 74 } 75 76 int cert_add_ext(X509 *issuer, X509 *subject, int nid, char *value) 77 { 78 X509_EXTENSION *ex; 79 X509V3_CTX ctx; 80 81 /* No configuration database */ 82 X509V3_set_ctx_nodb(&ctx); 83 84 /* Set issuer and subject certificates in the context */ 85 X509V3_set_ctx(&ctx, issuer, subject, NULL, NULL, 0); 86 ex = X509V3_EXT_conf_nid(NULL, &ctx, nid, value); 87 if (!ex) { 88 ERR_print_errors_fp(stdout); 89 return 0; 90 } 91 92 X509_add_ext(subject, ex, -1); 93 X509_EXTENSION_free(ex); 94 95 return 1; 96 } 97 98 99 int cert_new(cert_t *cert, int days, int ca, STACK_OF(X509_EXTENSION) * sk) 100 { 101 EVP_PKEY *pkey = keys[cert->key].key; 102 cert_t *issuer_cert = &certs[cert->issuer]; 103 EVP_PKEY *ikey = keys[issuer_cert->key].key; 104 X509 *issuer = issuer_cert->x; 105 X509 *x = NULL; 106 X509_EXTENSION *ex = NULL; 107 X509_NAME *name = NULL; 108 ASN1_INTEGER *sno = NULL; 109 int i, num; 110 111 /* Create the certificate structure */ 112 x = X509_new(); 113 if (!x) { 114 return 0; 115 } 116 117 /* If we do not have a key, use the issuer key (the certificate will 118 * become self signed). This happens in content certificates. */ 119 if (!pkey) { 120 pkey = ikey; 121 } 122 123 /* If we do not have an issuer certificate, use our own (the certificate 124 * will become self signed) */ 125 if (!issuer) { 126 issuer = x; 127 } 128 129 /* x509.v3 */ 130 X509_set_version(x, 2); 131 132 /* Random serial number */ 133 sno = ASN1_INTEGER_new(); 134 rand_serial(NULL, sno); 135 X509_set_serialNumber(x, sno); 136 ASN1_INTEGER_free(sno); 137 138 X509_gmtime_adj(X509_get_notBefore(x), 0); 139 X509_gmtime_adj(X509_get_notAfter(x), (long)60*60*24*days); 140 X509_set_pubkey(x, pkey); 141 142 /* Subject name */ 143 name = X509_get_subject_name(x); 144 X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, 145 (const unsigned char *)cert->cn, -1, -1, 0); 146 X509_set_subject_name(x, name); 147 148 /* Issuer name */ 149 name = X509_get_issuer_name(x); 150 X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, 151 (const unsigned char *)issuer_cert->cn, -1, -1, 0); 152 X509_set_issuer_name(x, name); 153 154 /* Add various extensions: standard extensions */ 155 cert_add_ext(issuer, x, NID_subject_key_identifier, "hash"); 156 cert_add_ext(issuer, x, NID_authority_key_identifier, "keyid:always"); 157 if (ca) { 158 cert_add_ext(issuer, x, NID_basic_constraints, "CA:TRUE"); 159 cert_add_ext(issuer, x, NID_key_usage, "keyCertSign"); 160 } else { 161 cert_add_ext(issuer, x, NID_basic_constraints, "CA:FALSE"); 162 } 163 164 /* Add custom extensions */ 165 if (sk != NULL) { 166 num = sk_X509_EXTENSION_num(sk); 167 for (i = 0; i < num; i++) { 168 ex = sk_X509_EXTENSION_value(sk, i); 169 X509_add_ext(x, ex, -1); 170 } 171 } 172 173 /* Sign the certificate with the issuer key */ 174 if (!X509_sign(x, ikey, EVP_sha256())) { 175 ERR_print_errors_fp(stdout); 176 return 0; 177 } 178 179 cert->x = x; 180 return 1; 181 } 182