]>
Commit | Line | Data |
---|---|---|
7bf7a6d0 MTL |
1 | /* |
2 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. | |
b6f94dbe | 3 | * |
7bf7a6d0 MTL |
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 | |
3e575651 SL |
8 | */ |
9 | ||
10 | #include <stdio.h> | |
7bf7a6d0 | 11 | #include "internal/cryptlib.h" |
3e575651 SL |
12 | #include <openssl/bn.h> |
13 | #include <openssl/rsa.h> | |
14 | #include <openssl/objects.h> | |
15 | #include <openssl/x509.h> | |
7bf7a6d0 | 16 | #include "internal/x509_int.h" |
d3819813 | 17 | #include "rsa_locl.h" |
3e575651 SL |
18 | |
19 | /* Size of an SSL signature: MD5+SHA1 */ | |
d3819813 | 20 | #define SSL_SIG_LENGTH 36 |
3e575651 | 21 | |
7bf7a6d0 MTL |
22 | /* |
23 | * encode_pkcs1 encodes a DigestInfo prefix of hash |type| and digest |m|, as | |
24 | * described in EMSA-PKCS1-v1_5-ENCODE, RFC 3447 section 9.2 step 2. This | |
25 | * encodes the DigestInfo (T and tLen) but does not add the padding. | |
26 | * | |
27 | * On success, it returns one and sets |*out| to a newly allocated buffer | |
28 | * containing the result and |*out_len| to its length. The caller must free | |
29 | * |*out| with |OPENSSL_free|. Otherwise, it returns zero. | |
30 | */ | |
31 | static int encode_pkcs1(unsigned char **out, int *out_len, int type, | |
32 | const unsigned char *m, unsigned int m_len) | |
d3819813 MTL |
33 | { |
34 | X509_SIG sig; | |
b6f94dbe | 35 | X509_ALGOR algor; |
7bf7a6d0 | 36 | ASN1_TYPE parameter; |
d3819813 | 37 | ASN1_OCTET_STRING digest; |
7bf7a6d0 MTL |
38 | uint8_t *der = NULL; |
39 | int len; | |
40 | ||
41 | sig.algor = &algor; | |
42 | sig.algor->algorithm = OBJ_nid2obj(type); | |
43 | if (sig.algor->algorithm == NULL) { | |
44 | RSAerr(RSA_F_ENCODE_PKCS1, RSA_R_UNKNOWN_ALGORITHM_TYPE); | |
45 | return 0; | |
46 | } | |
47 | if (OBJ_length(sig.algor->algorithm) == 0) { | |
48 | RSAerr(RSA_F_ENCODE_PKCS1, | |
49 | RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); | |
d3819813 MTL |
50 | return 0; |
51 | } | |
7bf7a6d0 MTL |
52 | parameter.type = V_ASN1_NULL; |
53 | parameter.value.ptr = NULL; | |
54 | sig.algor->parameter = ¶meter; | |
55 | ||
56 | sig.digest = &digest; | |
57 | sig.digest->data = (unsigned char *)m; | |
58 | sig.digest->length = m_len; | |
59 | ||
60 | len = i2d_X509_SIG(&sig, &der); | |
61 | if (len < 0) | |
62 | return 0; | |
63 | ||
64 | *out = der; | |
65 | *out_len = len; | |
66 | return 1; | |
67 | } | |
68 | ||
69 | int RSA_sign(int type, const unsigned char *m, unsigned int m_len, | |
70 | unsigned char *sigret, unsigned int *siglen, RSA *rsa) | |
71 | { | |
72 | int encrypt_len, encoded_len = 0, ret = 0; | |
73 | unsigned char *tmps = NULL; | |
74 | const unsigned char *encoded = NULL; | |
75 | ||
76 | if (rsa->meth->rsa_sign) { | |
d3819813 MTL |
77 | return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa); |
78 | } | |
7bf7a6d0 MTL |
79 | |
80 | /* Compute the encoded digest. */ | |
d3819813 | 81 | if (type == NID_md5_sha1) { |
7bf7a6d0 MTL |
82 | /* |
83 | * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and | |
84 | * earlier. It has no DigestInfo wrapper but otherwise is | |
85 | * RSASSA-PKCS1-v1_5. | |
86 | */ | |
d3819813 MTL |
87 | if (m_len != SSL_SIG_LENGTH) { |
88 | RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH); | |
7bf7a6d0 | 89 | return 0; |
d3819813 | 90 | } |
7bf7a6d0 MTL |
91 | encoded_len = SSL_SIG_LENGTH; |
92 | encoded = m; | |
d3819813 | 93 | } else { |
7bf7a6d0 MTL |
94 | if (!encode_pkcs1(&tmps, &encoded_len, type, m, m_len)) |
95 | goto err; | |
96 | encoded = tmps; | |
b6f94dbe | 97 | } |
7bf7a6d0 MTL |
98 | |
99 | if (encoded_len > RSA_size(rsa) - RSA_PKCS1_PADDING_SIZE) { | |
d3819813 | 100 | RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); |
7bf7a6d0 | 101 | goto err; |
b6f94dbe | 102 | } |
7bf7a6d0 MTL |
103 | encrypt_len = RSA_private_encrypt(encoded_len, encoded, sigret, rsa, |
104 | RSA_PKCS1_PADDING); | |
105 | if (encrypt_len <= 0) | |
106 | goto err; | |
3e575651 | 107 | |
7bf7a6d0 MTL |
108 | *siglen = encrypt_len; |
109 | ret = 1; | |
3e575651 | 110 | |
7bf7a6d0 MTL |
111 | err: |
112 | OPENSSL_clear_free(tmps, (size_t)encoded_len); | |
b6f94dbe MTL |
113 | return ret; |
114 | } | |
115 | ||
7bf7a6d0 MTL |
116 | /* |
117 | * int_rsa_verify verifies an RSA signature in |sigbuf| using |rsa|. It may be | |
118 | * called in two modes. If |rm| is NULL, it verifies the signature for digest | |
119 | * |m|. Otherwise, it recovers the digest from the signature, writing the digest | |
120 | * to |rm| and the length to |*prm_len|. |type| is the NID of the digest | |
121 | * algorithm to use. It returns one on successful verification and zero | |
122 | * otherwise. | |
123 | */ | |
124 | int int_rsa_verify(int type, const unsigned char *m, unsigned int m_len, | |
d3819813 MTL |
125 | unsigned char *rm, size_t *prm_len, |
126 | const unsigned char *sigbuf, size_t siglen, RSA *rsa) | |
127 | { | |
7bf7a6d0 MTL |
128 | int decrypt_len, ret = 0, encoded_len = 0; |
129 | unsigned char *decrypt_buf = NULL, *encoded = NULL; | |
3e575651 | 130 | |
7bf7a6d0 | 131 | if (siglen != (size_t)RSA_size(rsa)) { |
b6f94dbe | 132 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH); |
7bf7a6d0 | 133 | return 0; |
b6f94dbe MTL |
134 | } |
135 | ||
7bf7a6d0 MTL |
136 | /* Recover the encoded digest. */ |
137 | decrypt_buf = OPENSSL_malloc(siglen); | |
138 | if (decrypt_buf == NULL) { | |
d3819813 MTL |
139 | RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE); |
140 | goto err; | |
141 | } | |
f4173af1 | 142 | |
7bf7a6d0 MTL |
143 | decrypt_len = RSA_public_decrypt((int)siglen, sigbuf, decrypt_buf, rsa, |
144 | RSA_PKCS1_PADDING); | |
145 | if (decrypt_len <= 0) | |
b6f94dbe | 146 | goto err; |
7bf7a6d0 MTL |
147 | |
148 | if (type == NID_md5_sha1) { | |
149 | /* | |
150 | * NID_md5_sha1 corresponds to the MD5/SHA1 combination in TLS 1.1 and | |
151 | * earlier. It has no DigestInfo wrapper but otherwise is | |
152 | * RSASSA-PKCS1-v1_5. | |
153 | */ | |
154 | if (decrypt_len != SSL_SIG_LENGTH) { | |
b6f94dbe | 155 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); |
7bf7a6d0 | 156 | goto err; |
f4173af1 | 157 | } |
3e575651 | 158 | |
7bf7a6d0 MTL |
159 | if (rm != NULL) { |
160 | memcpy(rm, decrypt_buf, SSL_SIG_LENGTH); | |
161 | *prm_len = SSL_SIG_LENGTH; | |
162 | } else { | |
163 | if (m_len != SSL_SIG_LENGTH) { | |
164 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH); | |
165 | goto err; | |
166 | } | |
3e575651 | 167 | |
7bf7a6d0 MTL |
168 | if (memcmp(decrypt_buf, m, SSL_SIG_LENGTH) != 0) { |
169 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); | |
170 | goto err; | |
171 | } | |
d3819813 | 172 | } |
7bf7a6d0 MTL |
173 | } else if (type == NID_mdc2 && decrypt_len == 2 + 16 |
174 | && decrypt_buf[0] == 0x04 && decrypt_buf[1] == 0x10) { | |
175 | /* | |
176 | * Oddball MDC2 case: signature can be OCTET STRING. check for correct | |
177 | * tag and length octets. | |
178 | */ | |
179 | if (rm != NULL) { | |
180 | memcpy(rm, decrypt_buf + 2, 16); | |
181 | *prm_len = 16; | |
182 | } else { | |
183 | if (m_len != 16) { | |
184 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH); | |
185 | goto err; | |
186 | } | |
f4173af1 | 187 | |
7bf7a6d0 MTL |
188 | if (memcmp(m, decrypt_buf + 2, 16) != 0) { |
189 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); | |
190 | goto err; | |
191 | } | |
192 | } | |
193 | } else { | |
b6f94dbe | 194 | /* |
7bf7a6d0 MTL |
195 | * If recovering the digest, extract a digest-sized output from the end |
196 | * of |decrypt_buf| for |encode_pkcs1|, then compare the decryption | |
197 | * output as in a standard verification. | |
b6f94dbe | 198 | */ |
7bf7a6d0 MTL |
199 | if (rm != NULL) { |
200 | const EVP_MD *md = EVP_get_digestbynid(type); | |
201 | if (md == NULL) { | |
202 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_UNKNOWN_ALGORITHM_TYPE); | |
203 | goto err; | |
204 | } | |
205 | ||
206 | m_len = EVP_MD_size(md); | |
207 | if (m_len > (size_t)decrypt_len) { | |
208 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH); | |
209 | goto err; | |
210 | } | |
211 | m = decrypt_buf + decrypt_len - m_len; | |
f4173af1 | 212 | } |
f4173af1 | 213 | |
7bf7a6d0 MTL |
214 | /* Construct the encoded digest and ensure it matches. */ |
215 | if (!encode_pkcs1(&encoded, &encoded_len, type, m, m_len)) | |
216 | goto err; | |
f4173af1 | 217 | |
7bf7a6d0 MTL |
218 | if (encoded_len != decrypt_len |
219 | || memcmp(encoded, decrypt_buf, encoded_len) != 0) { | |
220 | RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); | |
b6f94dbe MTL |
221 | goto err; |
222 | } | |
7bf7a6d0 MTL |
223 | |
224 | /* Output the recovered digest. */ | |
225 | if (rm != NULL) { | |
226 | memcpy(rm, m, m_len); | |
227 | *prm_len = m_len; | |
228 | } | |
b6f94dbe | 229 | } |
7bf7a6d0 MTL |
230 | |
231 | ret = 1; | |
232 | ||
233 | err: | |
234 | OPENSSL_clear_free(encoded, (size_t)encoded_len); | |
235 | OPENSSL_clear_free(decrypt_buf, siglen); | |
236 | return ret; | |
d3819813 MTL |
237 | } |
238 | ||
7bf7a6d0 | 239 | int RSA_verify(int type, const unsigned char *m, unsigned int m_len, |
d3819813 MTL |
240 | const unsigned char *sigbuf, unsigned int siglen, RSA *rsa) |
241 | { | |
242 | ||
7bf7a6d0 MTL |
243 | if (rsa->meth->rsa_verify) { |
244 | return rsa->meth->rsa_verify(type, m, m_len, sigbuf, siglen, rsa); | |
d3819813 | 245 | } |
3e575651 | 246 | |
7bf7a6d0 | 247 | return int_rsa_verify(type, m, m_len, NULL, NULL, sigbuf, siglen, rsa); |
d3819813 | 248 | } |