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 * RSA low level APIs are deprecated for public use, but still ok for
14 #include "internal/deprecated.h"
17 #include "internal/cryptlib.h"
18 #include <openssl/bn.h>
19 #include <openssl/rsa.h>
20 #include <openssl/objects.h>
21 #include <openssl/x509.h>
22 #include "crypto/x509.h"
23 #ifndef OPENSSL_NO_MD2
24 # include <openssl/md2.h> /* uses MD2_DIGEST_LENGTH */
26 #ifndef OPENSSL_NO_MD5
27 # include <openssl/md5.h> /* uses MD5_DIGEST_LENGTH */
29 #ifndef OPENSSL_NO_MDC2
30 # include <openssl/mdc2.h> /* uses MDC2_DIGEST_LENGTH */
32 #include <openssl/sha.h> /* uses SHA???_DIGEST_LENGTH */
33 #include "rsa_local.h"
36 * The general purpose ASN1 code is not available inside the FIPS provider.
37 * To remove the dependency RSASSA-PKCS1-v1_5 DigestInfo encodings can be
38 * treated as a special case by pregenerating the required ASN1 encoding.
39 * This encoding will also be shared by the default provider.
41 * The EMSA-PKCS1-v1_5 encoding method includes an ASN.1 value of type
42 * DigestInfo, where the type DigestInfo has the syntax
44 * DigestInfo ::= SEQUENCE {
45 * digestAlgorithm DigestAlgorithm,
49 * DigestAlgorithm ::= AlgorithmIdentifier {
50 * {PKCS1-v1-5DigestAlgorithms}
53 * The AlgorithmIdentifier is a sequence containing the digest OID and
54 * parameters (a value of type NULL).
56 * The ENCODE_DIGESTINFO_SHA() and ENCODE_DIGESTINFO_MD() macros define an
57 * initialized array containing the DER encoded DigestInfo for the specified
58 * SHA or MD digest. The content of the OCTET STRING is not included.
59 * |name| is the digest name.
60 * |n| is last byte in the encoded OID for the digest.
61 * |sz| is the digest length in bytes. It must not be greater than 110.
64 #define ASN1_SEQUENCE 0x30
65 #define ASN1_OCTET_STRING 0x04
66 #define ASN1_NULL 0x05
69 /* SHA OIDs are of the form: (2 16 840 1 101 3 4 2 |n|) */
70 #define ENCODE_DIGESTINFO_SHA(name, n, sz) \
71 static const unsigned char digestinfo_##name##_der[] = { \
72 ASN1_SEQUENCE, 0x11 + sz, \
73 ASN1_SEQUENCE, 0x0d, \
74 ASN1_OID, 0x09, 2 * 40 + 16, 0x86, 0x48, 1, 101, 3, 4, 2, n, \
76 ASN1_OCTET_STRING, sz \
79 /* MD2 and MD5 OIDs are of the form: (1 2 840 113549 2 |n|) */
80 #define ENCODE_DIGESTINFO_MD(name, n, sz) \
81 static const unsigned char digestinfo_##name##_der[] = { \
82 ASN1_SEQUENCE, 0x10 + sz, \
83 ASN1_SEQUENCE, 0x0c, \
84 ASN1_OID, 0x08, 1 * 40 + 2, 0x86, 0x48, 0x86, 0xf7, 0x0d, 2, n, \
86 ASN1_OCTET_STRING, sz \
90 # ifndef OPENSSL_NO_MD2
91 ENCODE_DIGESTINFO_MD(md2, 0x02, MD2_DIGEST_LENGTH)
93 # ifndef OPENSSL_NO_MD5
94 ENCODE_DIGESTINFO_MD(md5, 0x05, MD5_DIGEST_LENGTH)
96 # ifndef OPENSSL_NO_MDC2
97 /* MDC-2 (2 5 8 3 101) */
98 static const unsigned char digestinfo_mdc2_der[] = {
99 ASN1_SEQUENCE, 0x0c + MDC2_DIGEST_LENGTH,
101 ASN1_OID, 0x04, 2 * 40 + 5, 8, 3, 101,
103 ASN1_OCTET_STRING, MDC2_DIGEST_LENGTH
106 /* SHA-1 (1 3 14 3 2 26) */
107 static const unsigned char digestinfo_sha1_der[] = {
108 ASN1_SEQUENCE, 0x0d + SHA_DIGEST_LENGTH,
110 ASN1_OID, 0x05, 1 * 40 + 3, 14, 3, 2, 26,
112 ASN1_OCTET_STRING, SHA_DIGEST_LENGTH
115 #endif /* FIPS_MODE */
117 ENCODE_DIGESTINFO_SHA(sha256, 0x01, SHA256_DIGEST_LENGTH)
118 ENCODE_DIGESTINFO_SHA(sha384, 0x02, SHA384_DIGEST_LENGTH)
119 ENCODE_DIGESTINFO_SHA(sha512, 0x03, SHA512_DIGEST_LENGTH)
120 ENCODE_DIGESTINFO_SHA(sha224, 0x04, SHA224_DIGEST_LENGTH)
121 ENCODE_DIGESTINFO_SHA(sha512_224, 0x05, SHA224_DIGEST_LENGTH)
122 ENCODE_DIGESTINFO_SHA(sha512_256, 0x06, SHA256_DIGEST_LENGTH)
123 ENCODE_DIGESTINFO_SHA(sha3_224, 0x07, SHA224_DIGEST_LENGTH)
124 ENCODE_DIGESTINFO_SHA(sha3_256, 0x08, SHA256_DIGEST_LENGTH)
125 ENCODE_DIGESTINFO_SHA(sha3_384, 0x09, SHA384_DIGEST_LENGTH)
126 ENCODE_DIGESTINFO_SHA(sha3_512, 0x0a, SHA512_DIGEST_LENGTH)
128 #define MD_CASE(name) \
130 *len = sizeof(digestinfo_##name##_der); \
131 return digestinfo_##name##_der;
133 static const unsigned char *digestinfo_encoding(int nid, size_t *len)
137 # ifndef OPENSSL_NO_MDC2
140 # ifndef OPENSSL_NO_MD2
143 # ifndef OPENSSL_NO_MD5
147 #endif /* FIPS_MODE */
163 /* Size of an SSL signature: MD5+SHA1 */
164 #define SSL_SIG_LENGTH 36
167 * Encodes a DigestInfo prefix of hash |type| and digest |m|, as
168 * described in EMSA-PKCS1-v1_5-ENCODE, RFC 3447 section 9.2 step 2. This
169 * encodes the DigestInfo (T and tLen) but does not add the padding.
171 * On success, it returns one and sets |*out| to a newly allocated buffer
172 * containing the result and |*out_len| to its length. The caller must free
173 * |*out| with OPENSSL_free(). Otherwise, it returns zero.
175 static int encode_pkcs1(unsigned char **out, size_t *out_len, int type,
176 const unsigned char *m, size_t m_len)
178 size_t di_prefix_len, dig_info_len;
179 const unsigned char *di_prefix;
180 unsigned char *dig_info;
182 if (type == NID_undef) {
183 RSAerr(RSA_F_ENCODE_PKCS1, RSA_R_UNKNOWN_ALGORITHM_TYPE);
186 di_prefix = digestinfo_encoding(type, &di_prefix_len);
187 if (di_prefix == NULL) {
188 RSAerr(RSA_F_ENCODE_PKCS1,
189 RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
192 dig_info_len = di_prefix_len + m_len;
193 dig_info = OPENSSL_malloc(dig_info_len);
194 if (dig_info == NULL) {
195 RSAerr(RSA_F_ENCODE_PKCS1, ERR_R_MALLOC_FAILURE);
198 memcpy(dig_info, di_prefix, di_prefix_len);
199 memcpy(dig_info + di_prefix_len, m, m_len);
202 *out_len = dig_info_len;
206 int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
207 unsigned char *sigret, unsigned int *siglen, RSA *rsa)
209 int encrypt_len, ret = 0;
210 size_t encoded_len = 0;
211 unsigned char *tmps = NULL;
212 const unsigned char *encoded = NULL;
214 if (rsa->meth->rsa_sign != NULL)
215 return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa);
217 /* Compute the encoded digest. */
218 if (type == NID_md5_sha1) {
220 * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and
221 * earlier. It has no DigestInfo wrapper but otherwise is
224 if (m_len != SSL_SIG_LENGTH) {
225 RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH);
228 encoded_len = SSL_SIG_LENGTH;
231 if (!encode_pkcs1(&tmps, &encoded_len, type, m, m_len))
236 if (encoded_len + RSA_PKCS1_PADDING_SIZE > (size_t)RSA_size(rsa)) {
237 RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
240 encrypt_len = RSA_private_encrypt((int)encoded_len, encoded, sigret, rsa,
242 if (encrypt_len <= 0)
245 *siglen = encrypt_len;
249 OPENSSL_clear_free(tmps, encoded_len);
254 * Verify an RSA signature in |sigbuf| using |rsa|.
255 * |type| is the NID of the digest algorithm to use.
256 * If |rm| is NULL, it verifies the signature for digest |m|, otherwise
257 * it recovers the digest from the signature, writing the digest to |rm| and
258 * the length to |*prm_len|.
260 * It returns one on successful verification or zero otherwise.
262 int int_rsa_verify(int type, const unsigned char *m, unsigned int m_len,
263 unsigned char *rm, size_t *prm_len,
264 const unsigned char *sigbuf, size_t siglen, RSA *rsa)
267 size_t decrypt_len, encoded_len = 0;
268 unsigned char *decrypt_buf = NULL, *encoded = NULL;
270 if (siglen != (size_t)RSA_size(rsa)) {
271 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH);
275 /* Recover the encoded digest. */
276 decrypt_buf = OPENSSL_malloc(siglen);
277 if (decrypt_buf == NULL) {
278 RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE);
282 len = RSA_public_decrypt((int)siglen, sigbuf, decrypt_buf, rsa,
288 if (type == NID_md5_sha1) {
290 * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and
291 * earlier. It has no DigestInfo wrapper but otherwise is
294 if (decrypt_len != SSL_SIG_LENGTH) {
295 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
300 memcpy(rm, decrypt_buf, SSL_SIG_LENGTH);
301 *prm_len = SSL_SIG_LENGTH;
303 if (m_len != SSL_SIG_LENGTH) {
304 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH);
308 if (memcmp(decrypt_buf, m, SSL_SIG_LENGTH) != 0) {
309 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
313 } else if (type == NID_mdc2 && decrypt_len == 2 + 16
314 && decrypt_buf[0] == 0x04 && decrypt_buf[1] == 0x10) {
316 * Oddball MDC2 case: signature can be OCTET STRING. check for correct
317 * tag and length octets.
320 memcpy(rm, decrypt_buf + 2, 16);
324 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH);
328 if (memcmp(m, decrypt_buf + 2, 16) != 0) {
329 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
335 * If recovering the digest, extract a digest-sized output from the end
336 * of |decrypt_buf| for |encode_pkcs1|, then compare the decryption
337 * output as in a standard verification.
340 const EVP_MD *md = EVP_get_digestbynid(type);
342 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_UNKNOWN_ALGORITHM_TYPE);
346 len = EVP_MD_size(md);
349 m_len = (unsigned int)len;
350 if (m_len > decrypt_len) {
351 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH);
354 m = decrypt_buf + decrypt_len - m_len;
357 /* Construct the encoded digest and ensure it matches. */
358 if (!encode_pkcs1(&encoded, &encoded_len, type, m, m_len))
361 if (encoded_len != decrypt_len
362 || memcmp(encoded, decrypt_buf, encoded_len) != 0) {
363 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
367 /* Output the recovered digest. */
369 memcpy(rm, m, m_len);
377 OPENSSL_clear_free(encoded, encoded_len);
378 OPENSSL_clear_free(decrypt_buf, siglen);
382 int RSA_verify(int type, const unsigned char *m, unsigned int m_len,
383 const unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
386 if (rsa->meth->rsa_verify != NULL)
387 return rsa->meth->rsa_verify(type, m, m_len, sigbuf, siglen, rsa);
389 return int_rsa_verify(type, m, m_len, NULL, NULL, sigbuf, siglen, rsa);