2 * Copyright 1995-2019 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 #include "internal/cryptlib.h"
12 #include <openssl/bn.h>
13 #include <openssl/rsa.h>
14 #include <openssl/objects.h>
15 #include <openssl/x509.h>
16 #include "crypto/x509.h"
17 #ifndef OPENSSL_NO_MD2
18 # include <openssl/md2.h> /* uses MD2_DIGEST_LENGTH */
20 #ifndef OPENSSL_NO_MD5
21 # include <openssl/md5.h> /* uses MD5_DIGEST_LENGTH */
23 #ifndef OPENSSL_NO_MDC2
24 # include <openssl/mdc2.h> /* uses MDC2_DIGEST_LENGTH */
26 #include <openssl/sha.h> /* uses SHA???_DIGEST_LENGTH */
27 #include "rsa_local.h"
30 * The general purpose ASN1 code is not available inside the FIPS provider.
31 * To remove the dependency RSASSA-PKCS1-v1_5 DigestInfo encodings can be
32 * treated as a special case by pregenerating the required ASN1 encoding.
33 * This encoding will also be shared by the default provider.
35 * The EMSA-PKCS1-v1_5 encoding method includes an ASN.1 value of type
36 * DigestInfo, where the type DigestInfo has the syntax
38 * DigestInfo ::= SEQUENCE {
39 * digestAlgorithm DigestAlgorithm,
43 * DigestAlgorithm ::= AlgorithmIdentifier {
44 * {PKCS1-v1-5DigestAlgorithms}
47 * The AlgorithmIdentifier is a sequence containing the digest OID and
48 * parameters (a value of type NULL).
50 * The ENCODE_DIGESTINFO_SHA() and ENCODE_DIGESTINFO_MD() macros define an
51 * initialized array containing the DER encoded DigestInfo for the specified
52 * SHA or MD digest. The content of the OCTET STRING is not included.
53 * |name| is the digest name.
54 * |n| is last byte in the encoded OID for the digest.
55 * |sz| is the digest length in bytes. It must not be greater than 110.
58 #define ASN1_SEQUENCE 0x30
59 #define ASN1_OCTET_STRING 0x04
60 #define ASN1_NULL 0x05
63 /* SHA OIDs are of the form: (2 16 840 1 101 3 4 2 |n|) */
64 #define ENCODE_DIGESTINFO_SHA(name, n, sz) \
65 static const unsigned char digestinfo_##name##_der[] = { \
66 ASN1_SEQUENCE, 0x11 + sz, \
67 ASN1_SEQUENCE, 0x0d, \
68 ASN1_OID, 0x09, 2 * 40 + 16, 0x86, 0x48, 1, 101, 3, 4, 2, n, \
70 ASN1_OCTET_STRING, sz \
73 /* MD2 and MD5 OIDs are of the form: (1 2 840 113549 2 |n|) */
74 #define ENCODE_DIGESTINFO_MD(name, n, sz) \
75 static const unsigned char digestinfo_##name##_der[] = { \
76 ASN1_SEQUENCE, 0x10 + sz, \
77 ASN1_SEQUENCE, 0x0c, \
78 ASN1_OID, 0x08, 1 * 40 + 2, 0x86, 0x48, 0x86, 0xf7, 0x0d, 2, n, \
80 ASN1_OCTET_STRING, sz \
84 # ifndef OPENSSL_NO_MD2
85 ENCODE_DIGESTINFO_MD(md2, 0x02, MD2_DIGEST_LENGTH)
87 # ifndef OPENSSL_NO_MD5
88 ENCODE_DIGESTINFO_MD(md5, 0x05, MD5_DIGEST_LENGTH)
90 # ifndef OPENSSL_NO_MDC2
91 /* MDC-2 (2 5 8 3 101) */
92 static const unsigned char digestinfo_mdc2_der[] = {
93 ASN1_SEQUENCE, 0x0c + MDC2_DIGEST_LENGTH,
95 ASN1_OID, 0x04, 2 * 40 + 5, 8, 3, 101,
97 ASN1_OCTET_STRING, MDC2_DIGEST_LENGTH
100 /* SHA-1 (1 3 14 3 2 26) */
101 static const unsigned char digestinfo_sha1_der[] = {
102 ASN1_SEQUENCE, 0x0d + SHA_DIGEST_LENGTH,
104 ASN1_OID, 0x05, 1 * 40 + 3, 14, 3, 2, 26,
106 ASN1_OCTET_STRING, SHA_DIGEST_LENGTH
109 #endif /* FIPS_MODE */
111 ENCODE_DIGESTINFO_SHA(sha256, 0x01, SHA256_DIGEST_LENGTH)
112 ENCODE_DIGESTINFO_SHA(sha384, 0x02, SHA384_DIGEST_LENGTH)
113 ENCODE_DIGESTINFO_SHA(sha512, 0x03, SHA512_DIGEST_LENGTH)
114 ENCODE_DIGESTINFO_SHA(sha224, 0x04, SHA224_DIGEST_LENGTH)
115 ENCODE_DIGESTINFO_SHA(sha512_224, 0x05, SHA224_DIGEST_LENGTH)
116 ENCODE_DIGESTINFO_SHA(sha512_256, 0x06, SHA256_DIGEST_LENGTH)
117 ENCODE_DIGESTINFO_SHA(sha3_224, 0x07, SHA224_DIGEST_LENGTH)
118 ENCODE_DIGESTINFO_SHA(sha3_256, 0x08, SHA256_DIGEST_LENGTH)
119 ENCODE_DIGESTINFO_SHA(sha3_384, 0x09, SHA384_DIGEST_LENGTH)
120 ENCODE_DIGESTINFO_SHA(sha3_512, 0x0a, SHA512_DIGEST_LENGTH)
122 #define MD_CASE(name) \
124 *len = sizeof(digestinfo_##name##_der); \
125 return digestinfo_##name##_der;
127 static const unsigned char *digestinfo_encoding(int nid, size_t *len)
131 # ifndef OPENSSL_NO_MDC2
134 # ifndef OPENSSL_NO_MD2
137 # ifndef OPENSSL_NO_MD5
141 #endif /* FIPS_MODE */
157 /* Size of an SSL signature: MD5+SHA1 */
158 #define SSL_SIG_LENGTH 36
161 * Encodes a DigestInfo prefix of hash |type| and digest |m|, as
162 * described in EMSA-PKCS1-v1_5-ENCODE, RFC 3447 section 9.2 step 2. This
163 * encodes the DigestInfo (T and tLen) but does not add the padding.
165 * On success, it returns one and sets |*out| to a newly allocated buffer
166 * containing the result and |*out_len| to its length. The caller must free
167 * |*out| with OPENSSL_free(). Otherwise, it returns zero.
169 static int encode_pkcs1(unsigned char **out, size_t *out_len, int type,
170 const unsigned char *m, size_t m_len)
172 size_t di_prefix_len, dig_info_len;
173 const unsigned char *di_prefix;
174 unsigned char *dig_info;
176 if (type == NID_undef) {
177 RSAerr(RSA_F_ENCODE_PKCS1, RSA_R_UNKNOWN_ALGORITHM_TYPE);
180 di_prefix = digestinfo_encoding(type, &di_prefix_len);
181 if (di_prefix == NULL) {
182 RSAerr(RSA_F_ENCODE_PKCS1,
183 RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
186 dig_info_len = di_prefix_len + m_len;
187 dig_info = OPENSSL_malloc(dig_info_len);
188 if (dig_info == NULL) {
189 RSAerr(RSA_F_ENCODE_PKCS1, ERR_R_MALLOC_FAILURE);
192 memcpy(dig_info, di_prefix, di_prefix_len);
193 memcpy(dig_info + di_prefix_len, m, m_len);
196 *out_len = dig_info_len;
200 int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
201 unsigned char *sigret, unsigned int *siglen, RSA *rsa)
203 int encrypt_len, ret = 0;
204 size_t encoded_len = 0;
205 unsigned char *tmps = NULL;
206 const unsigned char *encoded = NULL;
208 if (rsa->meth->rsa_sign != NULL)
209 return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa);
211 /* Compute the encoded digest. */
212 if (type == NID_md5_sha1) {
214 * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and
215 * earlier. It has no DigestInfo wrapper but otherwise is
218 if (m_len != SSL_SIG_LENGTH) {
219 RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH);
222 encoded_len = SSL_SIG_LENGTH;
225 if (!encode_pkcs1(&tmps, &encoded_len, type, m, m_len))
230 if (encoded_len + RSA_PKCS1_PADDING_SIZE > (size_t)RSA_size(rsa)) {
231 RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
234 encrypt_len = RSA_private_encrypt((int)encoded_len, encoded, sigret, rsa,
236 if (encrypt_len <= 0)
239 *siglen = encrypt_len;
243 OPENSSL_clear_free(tmps, encoded_len);
248 * Verify an RSA signature in |sigbuf| using |rsa|.
249 * |type| is the NID of the digest algorithm to use.
250 * If |rm| is NULL, it verifies the signature for digest |m|, otherwise
251 * it recovers the digest from the signature, writing the digest to |rm| and
252 * the length to |*prm_len|.
254 * It returns one on successful verification or zero otherwise.
256 int int_rsa_verify(int type, const unsigned char *m, unsigned int m_len,
257 unsigned char *rm, size_t *prm_len,
258 const unsigned char *sigbuf, size_t siglen, RSA *rsa)
261 size_t decrypt_len, encoded_len = 0;
262 unsigned char *decrypt_buf = NULL, *encoded = NULL;
264 if (siglen != (size_t)RSA_size(rsa)) {
265 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH);
269 /* Recover the encoded digest. */
270 decrypt_buf = OPENSSL_malloc(siglen);
271 if (decrypt_buf == NULL) {
272 RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE);
276 len = RSA_public_decrypt((int)siglen, sigbuf, decrypt_buf, rsa,
282 if (type == NID_md5_sha1) {
284 * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and
285 * earlier. It has no DigestInfo wrapper but otherwise is
288 if (decrypt_len != SSL_SIG_LENGTH) {
289 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
294 memcpy(rm, decrypt_buf, SSL_SIG_LENGTH);
295 *prm_len = SSL_SIG_LENGTH;
297 if (m_len != SSL_SIG_LENGTH) {
298 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH);
302 if (memcmp(decrypt_buf, m, SSL_SIG_LENGTH) != 0) {
303 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
307 } else if (type == NID_mdc2 && decrypt_len == 2 + 16
308 && decrypt_buf[0] == 0x04 && decrypt_buf[1] == 0x10) {
310 * Oddball MDC2 case: signature can be OCTET STRING. check for correct
311 * tag and length octets.
314 memcpy(rm, decrypt_buf + 2, 16);
318 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH);
322 if (memcmp(m, decrypt_buf + 2, 16) != 0) {
323 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
329 * If recovering the digest, extract a digest-sized output from the end
330 * of |decrypt_buf| for |encode_pkcs1|, then compare the decryption
331 * output as in a standard verification.
334 const EVP_MD *md = EVP_get_digestbynid(type);
336 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_UNKNOWN_ALGORITHM_TYPE);
340 len = EVP_MD_size(md);
343 m_len = (unsigned int)len;
344 if (m_len > decrypt_len) {
345 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH);
348 m = decrypt_buf + decrypt_len - m_len;
351 /* Construct the encoded digest and ensure it matches. */
352 if (!encode_pkcs1(&encoded, &encoded_len, type, m, m_len))
355 if (encoded_len != decrypt_len
356 || memcmp(encoded, decrypt_buf, encoded_len) != 0) {
357 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
361 /* Output the recovered digest. */
363 memcpy(rm, m, m_len);
371 OPENSSL_clear_free(encoded, encoded_len);
372 OPENSSL_clear_free(decrypt_buf, siglen);
376 int RSA_verify(int type, const unsigned char *m, unsigned int m_len,
377 const unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
380 if (rsa->meth->rsa_verify != NULL)
381 return rsa->meth->rsa_verify(type, m, m_len, sigbuf, siglen, rsa);
383 return int_rsa_verify(type, m, m_len, NULL, NULL, sigbuf, siglen, rsa);