2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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(void)
25 SCT_CTX *sctx = OPENSSL_zalloc(sizeof(*sctx));
28 CTerr(CT_F_SCT_CTX_NEW, ERR_R_MALLOC_FAILURE);
33 void SCT_CTX_free(SCT_CTX *sctx)
37 EVP_PKEY_free(sctx->pkey);
38 OPENSSL_free(sctx->pkeyhash);
39 OPENSSL_free(sctx->ihash);
40 OPENSSL_free(sctx->certder);
41 OPENSSL_free(sctx->preder);
46 * Finds the index of the first extension with the given NID in cert.
47 * If there is more than one extension with that NID, *is_duplicated is set to
48 * 1, otherwise 0 (unless it is NULL).
50 static int ct_x509_get_ext(X509 *cert, int nid, int *is_duplicated)
52 int ret = X509_get_ext_by_NID(cert, nid, -1);
54 if (is_duplicated != NULL)
55 *is_duplicated = ret >= 0 && X509_get_ext_by_NID(cert, nid, ret) >= 0;
61 * Modifies a certificate by deleting extensions and copying the issuer and
62 * AKID from the presigner certificate, if necessary.
63 * Returns 1 on success, 0 otherwise.
65 __owur static int ct_x509_cert_fixup(X509 *cert, X509 *presigner)
68 int pre_akid_ext_is_dup, cert_akid_ext_is_dup;
70 if (presigner == NULL)
73 preidx = ct_x509_get_ext(presigner, NID_authority_key_identifier,
74 &pre_akid_ext_is_dup);
75 certidx = ct_x509_get_ext(cert, NID_authority_key_identifier,
76 &cert_akid_ext_is_dup);
78 /* An error occurred whilst searching for the extension */
79 if (preidx < -1 || certidx < -1)
81 /* Invalid certificate if they contain duplicate extensions */
82 if (pre_akid_ext_is_dup || cert_akid_ext_is_dup)
84 /* AKID must be present in both certificate or absent in both */
85 if (preidx >= 0 && certidx == -1)
87 if (preidx == -1 && certidx >= 0)
89 /* Copy issuer name */
90 if (!X509_set_issuer_name(cert, X509_get_issuer_name(presigner)))
93 /* Retrieve and copy AKID encoding */
94 X509_EXTENSION *preext = X509_get_ext(presigner, preidx);
95 X509_EXTENSION *certext = X509_get_ext(cert, certidx);
96 ASN1_OCTET_STRING *preextdata;
98 /* Should never happen */
99 if (preext == NULL || certext == NULL)
101 preextdata = X509_EXTENSION_get_data(preext);
102 if (preextdata == NULL ||
103 !X509_EXTENSION_set_data(certext, preextdata))
109 int SCT_CTX_set1_cert(SCT_CTX *sctx, X509 *cert, X509 *presigner)
111 unsigned char *certder = NULL, *preder = NULL;
113 int certderlen = 0, prederlen = 0;
115 int poison_ext_is_dup, sct_ext_is_dup;
116 int poison_idx = ct_x509_get_ext(cert, NID_ct_precert_poison, &poison_ext_is_dup);
118 /* Duplicate poison extensions are present - error */
119 if (poison_ext_is_dup)
122 /* If *cert doesn't have a poison extension, it isn't a precert */
123 if (poison_idx == -1) {
124 /* cert isn't a precert, so we shouldn't have a presigner */
125 if (presigner != NULL)
128 certderlen = i2d_X509(cert, &certder);
133 /* See if cert has a precert SCTs extension */
134 idx = ct_x509_get_ext(cert, NID_ct_precert_scts, &sct_ext_is_dup);
135 /* Duplicate SCT extensions are present - error */
139 if (idx >= 0 && poison_idx >= 0) {
141 * cert can't both contain SCTs (i.e. have an SCT extension) and be a
142 * precert (i.e. have a poison extension).
152 * If either a poison or SCT extension is present, remove it before encoding
153 * cert. This, along with ct_x509_cert_fixup(), gets a TBSCertificate (see
154 * RFC5280) from cert, which is what the CT log signed when it produced the
160 /* Take a copy of certificate so we don't modify passed version */
161 pretmp = X509_dup(cert);
165 ext = X509_delete_ext(pretmp, idx);
166 X509_EXTENSION_free(ext);
168 if (!ct_x509_cert_fixup(pretmp, presigner))
171 prederlen = i2d_re_X509_tbs(pretmp, &preder);
178 OPENSSL_free(sctx->certder);
179 sctx->certder = certder;
180 sctx->certderlen = certderlen;
182 OPENSSL_free(sctx->preder);
183 sctx->preder = preder;
184 sctx->prederlen = prederlen;
188 OPENSSL_free(certder);
189 OPENSSL_free(preder);
194 __owur static int ct_public_key_hash(X509_PUBKEY *pkey, unsigned char **hash,
198 unsigned char *md = NULL, *der = NULL;
202 /* Reuse buffer if possible */
203 if (*hash != NULL && *hash_len >= SHA256_DIGEST_LENGTH) {
206 md = OPENSSL_malloc(SHA256_DIGEST_LENGTH);
211 /* Calculate key hash */
212 der_len = i2d_X509_PUBKEY(pkey, &der);
216 if (!EVP_Digest(der, der_len, md, &md_len, EVP_sha256(), NULL))
222 *hash_len = SHA256_DIGEST_LENGTH;
233 int SCT_CTX_set1_issuer(SCT_CTX *sctx, const X509 *issuer)
235 return SCT_CTX_set1_issuer_pubkey(sctx, X509_get_X509_PUBKEY(issuer));
238 int SCT_CTX_set1_issuer_pubkey(SCT_CTX *sctx, X509_PUBKEY *pubkey)
240 return ct_public_key_hash(pubkey, &sctx->ihash, &sctx->ihashlen);
243 int SCT_CTX_set1_pubkey(SCT_CTX *sctx, X509_PUBKEY *pubkey)
245 EVP_PKEY *pkey = X509_PUBKEY_get(pubkey);
250 if (!ct_public_key_hash(pubkey, &sctx->pkeyhash, &sctx->pkeyhashlen)) {
255 EVP_PKEY_free(sctx->pkey);
260 void SCT_CTX_set_time(SCT_CTX *sctx, uint64_t time_in_ms)
262 sctx->epoch_time_in_ms = time_in_ms;