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
);