1 /* Copyright (C) 1995-1998 Eric Young ([email protected])
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young ([email protected]).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson ([email protected]).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young ([email protected])"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson ([email protected])"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57 #include <openssl/x509.h>
58
59 #include <openssl/asn1.h>
60 #include <openssl/digest.h>
61 #include <openssl/err.h>
62 #include <openssl/evp.h>
63 #include <openssl/obj.h>
64
65 #include "internal.h"
66
67 // Restrict the digests that are allowed in X509 certificates
x509_digest_nid_ok(const int digest_nid)68 static int x509_digest_nid_ok(const int digest_nid) {
69 switch (digest_nid) {
70 case NID_md4:
71 case NID_md5:
72 return 0;
73 }
74 return 1;
75 }
76
x509_digest_sign_algorithm(EVP_MD_CTX * ctx,X509_ALGOR * algor)77 int x509_digest_sign_algorithm(EVP_MD_CTX *ctx, X509_ALGOR *algor) {
78 EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(ctx->pctx);
79 if (pkey == NULL) {
80 OPENSSL_PUT_ERROR(ASN1, ASN1_R_CONTEXT_NOT_INITIALISED);
81 return 0;
82 }
83
84 if (EVP_PKEY_id(pkey) == EVP_PKEY_RSA) {
85 int pad_mode;
86 if (!EVP_PKEY_CTX_get_rsa_padding(ctx->pctx, &pad_mode)) {
87 return 0;
88 }
89 // RSA-PSS has special signature algorithm logic.
90 if (pad_mode == RSA_PKCS1_PSS_PADDING) {
91 return x509_rsa_ctx_to_pss(ctx, algor);
92 }
93 }
94
95 if (EVP_PKEY_id(pkey) == EVP_PKEY_ED25519) {
96 return X509_ALGOR_set0(algor, OBJ_nid2obj(NID_ED25519), V_ASN1_UNDEF, NULL);
97 }
98
99 // Default behavior: look up the OID for the algorithm/hash pair and encode
100 // that.
101 const EVP_MD *digest = EVP_MD_CTX_md(ctx);
102 if (digest == NULL) {
103 OPENSSL_PUT_ERROR(ASN1, ASN1_R_CONTEXT_NOT_INITIALISED);
104 return 0;
105 }
106
107 const int digest_nid = EVP_MD_type(digest);
108 int sign_nid;
109 if (!x509_digest_nid_ok(digest_nid) ||
110 !OBJ_find_sigid_by_algs(&sign_nid, digest_nid, EVP_PKEY_id(pkey))) {
111 OPENSSL_PUT_ERROR(ASN1, ASN1_R_DIGEST_AND_KEY_TYPE_NOT_SUPPORTED);
112 return 0;
113 }
114
115 // RSA signature algorithms include an explicit NULL parameter. Others omit
116 // it.
117 int paramtype =
118 (EVP_PKEY_id(pkey) == EVP_PKEY_RSA) ? V_ASN1_NULL : V_ASN1_UNDEF;
119 return X509_ALGOR_set0(algor, OBJ_nid2obj(sign_nid), paramtype, NULL);
120 }
121
x509_digest_verify_init(EVP_MD_CTX * ctx,const X509_ALGOR * sigalg,EVP_PKEY * pkey)122 int x509_digest_verify_init(EVP_MD_CTX *ctx, const X509_ALGOR *sigalg,
123 EVP_PKEY *pkey) {
124 // Convert the signature OID into digest and public key OIDs.
125 int sigalg_nid = OBJ_obj2nid(sigalg->algorithm);
126 int digest_nid, pkey_nid;
127 if (!OBJ_find_sigid_algs(sigalg_nid, &digest_nid, &pkey_nid)) {
128 OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
129 return 0;
130 }
131
132 // Check the public key OID matches the public key type.
133 if (pkey_nid != EVP_PKEY_id(pkey)) {
134 OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_PUBLIC_KEY_TYPE);
135 return 0;
136 }
137
138 // Check for permitted digest algorithms
139 if (!x509_digest_nid_ok(digest_nid)) {
140 OPENSSL_PUT_ERROR(ASN1, ASN1_R_DIGEST_AND_KEY_TYPE_NOT_SUPPORTED);
141 return 0;
142 }
143
144 // NID_undef signals that there are custom parameters to set.
145 if (digest_nid == NID_undef) {
146 if (sigalg_nid == NID_rsassaPss) {
147 return x509_rsa_pss_to_ctx(ctx, sigalg, pkey);
148 }
149 if (sigalg_nid == NID_ED25519) {
150 if (sigalg->parameter != NULL) {
151 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PARAMETER);
152 return 0;
153 }
154 return EVP_DigestVerifyInit(ctx, NULL, NULL, NULL, pkey);
155 }
156 OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
157 return 0;
158 }
159
160 // The parameter should be an explicit NULL for RSA and omitted for ECDSA. For
161 // compatibility, we allow either for both algorithms. See b/167375496.
162 //
163 // TODO(davidben): Chromium's verifier allows both forms for RSA, but enforces
164 // ECDSA more strictly. Align with Chromium and add a flag for b/167375496.
165 if (sigalg->parameter != NULL && sigalg->parameter->type != V_ASN1_NULL) {
166 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PARAMETER);
167 return 0;
168 }
169
170 // Otherwise, initialize with the digest from the OID.
171 const EVP_MD *digest = EVP_get_digestbynid(digest_nid);
172 if (digest == NULL) {
173 OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
174 return 0;
175 }
176
177 return EVP_DigestVerifyInit(ctx, NULL, digest, NULL, pkey);
178 }
179