2 * Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 # error "CT is disabled"
17 #include <openssl/err.h>
18 #include <openssl/obj_mac.h>
19 #include <openssl/x509.h>
23 SCT_CTX *SCT_CTX_new(OSSL_LIB_CTX *libctx, const char *propq)
25 SCT_CTX *sctx = OPENSSL_zalloc(sizeof(*sctx));
30 sctx->libctx = libctx;
32 sctx->propq = OPENSSL_strdup(propq);
33 if (sctx->propq == NULL) {
42 void SCT_CTX_free(SCT_CTX *sctx)
46 EVP_PKEY_free(sctx->pkey);
47 OPENSSL_free(sctx->pkeyhash);
48 OPENSSL_free(sctx->ihash);
49 OPENSSL_free(sctx->certder);
50 OPENSSL_free(sctx->preder);
51 OPENSSL_free(sctx->propq);
56 * Finds the index of the first extension with the given NID in cert.
57 * If there is more than one extension with that NID, *is_duplicated is set to
58 * 1, otherwise 0 (unless it is NULL).
60 static int ct_x509_get_ext(X509 *cert, int nid, int *is_duplicated)
62 int ret = X509_get_ext_by_NID(cert, nid, -1);
64 if (is_duplicated != NULL)
65 *is_duplicated = ret >= 0 && X509_get_ext_by_NID(cert, nid, ret) >= 0;
71 * Modifies a certificate by deleting extensions and copying the issuer and
72 * AKID from the presigner certificate, if necessary.
73 * Returns 1 on success, 0 otherwise.
75 __owur static int ct_x509_cert_fixup(X509 *cert, X509 *presigner)
78 int pre_akid_ext_is_dup, cert_akid_ext_is_dup;
80 if (presigner == NULL)
83 preidx = ct_x509_get_ext(presigner, NID_authority_key_identifier,
84 &pre_akid_ext_is_dup);
85 certidx = ct_x509_get_ext(cert, NID_authority_key_identifier,
86 &cert_akid_ext_is_dup);
88 /* An error occurred whilst searching for the extension */
89 if (preidx < -1 || certidx < -1)
91 /* Invalid certificate if they contain duplicate extensions */
92 if (pre_akid_ext_is_dup || cert_akid_ext_is_dup)
94 /* AKID must be present in both certificate or absent in both */
95 if (preidx >= 0 && certidx == -1)
97 if (preidx == -1 && certidx >= 0)
99 /* Copy issuer name */
100 if (!X509_set_issuer_name(cert, X509_get_issuer_name(presigner)))
103 /* Retrieve and copy AKID encoding */
104 X509_EXTENSION *preext = X509_get_ext(presigner, preidx);
105 X509_EXTENSION *certext = X509_get_ext(cert, certidx);
106 ASN1_OCTET_STRING *preextdata;
108 /* Should never happen */
109 if (preext == NULL || certext == NULL)
111 preextdata = X509_EXTENSION_get_data(preext);
112 if (preextdata == NULL ||
113 !X509_EXTENSION_set_data(certext, preextdata))
119 int SCT_CTX_set1_cert(SCT_CTX *sctx, X509 *cert, X509 *presigner)
121 unsigned char *certder = NULL, *preder = NULL;
123 int certderlen = 0, prederlen = 0;
125 int poison_ext_is_dup, sct_ext_is_dup;
126 int poison_idx = ct_x509_get_ext(cert, NID_ct_precert_poison, &poison_ext_is_dup);
128 /* Duplicate poison extensions are present - error */
129 if (poison_ext_is_dup)
132 /* If *cert doesn't have a poison extension, it isn't a precert */
133 if (poison_idx == -1) {
134 /* cert isn't a precert, so we shouldn't have a presigner */
135 if (presigner != NULL)
138 certderlen = i2d_X509(cert, &certder);
143 /* See if cert has a precert SCTs extension */
144 idx = ct_x509_get_ext(cert, NID_ct_precert_scts, &sct_ext_is_dup);
145 /* Duplicate SCT extensions are present - error */
149 if (idx >= 0 && poison_idx >= 0) {
151 * cert can't both contain SCTs (i.e. have an SCT extension) and be a
152 * precert (i.e. have a poison extension).
162 * If either a poison or SCT extension is present, remove it before encoding
163 * cert. This, along with ct_x509_cert_fixup(), gets a TBSCertificate (see
164 * RFC5280) from cert, which is what the CT log signed when it produced the
168 /* Take a copy of certificate so we don't modify passed version */
169 pretmp = X509_dup(cert);
173 X509_EXTENSION_free(X509_delete_ext(pretmp, idx));
175 if (!ct_x509_cert_fixup(pretmp, presigner))
178 prederlen = i2d_re_X509_tbs(pretmp, &preder);
185 OPENSSL_free(sctx->certder);
186 sctx->certder = certder;
187 sctx->certderlen = certderlen;
189 OPENSSL_free(sctx->preder);
190 sctx->preder = preder;
191 sctx->prederlen = prederlen;
195 OPENSSL_free(certder);
196 OPENSSL_free(preder);
201 __owur static int ct_public_key_hash(SCT_CTX *sctx, X509_PUBKEY *pkey,
202 unsigned char **hash, size_t *hash_len)
205 unsigned char *md = NULL, *der = NULL;
208 EVP_MD *sha256 = EVP_MD_fetch(sctx->libctx, "SHA2-256", sctx->propq);
213 /* Reuse buffer if possible */
214 if (*hash != NULL && *hash_len >= SHA256_DIGEST_LENGTH) {
217 md = OPENSSL_malloc(SHA256_DIGEST_LENGTH);
222 /* Calculate key hash */
223 der_len = i2d_X509_PUBKEY(pkey, &der);
227 if (!EVP_Digest(der, der_len, md, &md_len, sha256, NULL))
233 *hash_len = SHA256_DIGEST_LENGTH;
245 int SCT_CTX_set1_issuer(SCT_CTX *sctx, const X509 *issuer)
247 return SCT_CTX_set1_issuer_pubkey(sctx, X509_get_X509_PUBKEY(issuer));
250 int SCT_CTX_set1_issuer_pubkey(SCT_CTX *sctx, X509_PUBKEY *pubkey)
252 return ct_public_key_hash(sctx, pubkey, &sctx->ihash, &sctx->ihashlen);
255 int SCT_CTX_set1_pubkey(SCT_CTX *sctx, X509_PUBKEY *pubkey)
257 EVP_PKEY *pkey = X509_PUBKEY_get(pubkey);
262 if (!ct_public_key_hash(sctx, pubkey, &sctx->pkeyhash, &sctx->pkeyhashlen)) {
267 EVP_PKEY_free(sctx->pkey);
272 void SCT_CTX_set_time(SCT_CTX *sctx, uint64_t time_in_ms)
274 sctx->epoch_time_in_ms = time_in_ms;