diff options
Diffstat (limited to 'src/lib/libcrypto/rsa/rsa_oaep.c')
-rw-r--r-- | src/lib/libcrypto/rsa/rsa_oaep.c | 155 |
1 files changed, 79 insertions, 76 deletions
diff --git a/src/lib/libcrypto/rsa/rsa_oaep.c b/src/lib/libcrypto/rsa/rsa_oaep.c index 695df4e0a0..f8f9935fac 100644 --- a/src/lib/libcrypto/rsa/rsa_oaep.c +++ b/src/lib/libcrypto/rsa/rsa_oaep.c | |||
@@ -1,4 +1,4 @@ | |||
1 | /* $OpenBSD: rsa_oaep.c,v 1.16 2014/06/12 15:49:30 deraadt Exp $ */ | 1 | /* $OpenBSD: rsa_oaep.c,v 1.17 2014/07/09 08:20:08 miod Exp $ */ |
2 | /* Written by Ulf Moeller. This software is distributed on an "AS IS" | 2 | /* Written by Ulf Moeller. This software is distributed on an "AS IS" |
3 | basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. */ | 3 | basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. */ |
4 | 4 | ||
@@ -28,29 +28,28 @@ | |||
28 | #include <openssl/rand.h> | 28 | #include <openssl/rand.h> |
29 | #include <openssl/sha.h> | 29 | #include <openssl/sha.h> |
30 | 30 | ||
31 | static int MGF1(unsigned char *mask, long len, | 31 | static int MGF1(unsigned char *mask, long len, const unsigned char *seed, |
32 | const unsigned char *seed, long seedlen); | 32 | long seedlen); |
33 | 33 | ||
34 | int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen, | 34 | int |
35 | const unsigned char *from, int flen, | 35 | RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen, |
36 | const unsigned char *param, int plen) | 36 | const unsigned char *from, int flen, const unsigned char *param, int plen) |
37 | { | 37 | { |
38 | int i, emlen = tlen - 1; | 38 | int i, emlen = tlen - 1; |
39 | unsigned char *db, *seed; | 39 | unsigned char *db, *seed; |
40 | unsigned char *dbmask, seedmask[SHA_DIGEST_LENGTH]; | 40 | unsigned char *dbmask, seedmask[SHA_DIGEST_LENGTH]; |
41 | 41 | ||
42 | if (flen > emlen - 2 * SHA_DIGEST_LENGTH - 1) | 42 | if (flen > emlen - 2 * SHA_DIGEST_LENGTH - 1) { |
43 | { | ||
44 | RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, | 43 | RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, |
45 | RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); | 44 | RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); |
46 | return 0; | 45 | return 0; |
47 | } | 46 | } |
48 | 47 | ||
49 | if (emlen < 2 * SHA_DIGEST_LENGTH + 1) | 48 | if (emlen < 2 * SHA_DIGEST_LENGTH + 1) { |
50 | { | 49 | RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, |
51 | RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL); | 50 | RSA_R_KEY_SIZE_TOO_SMALL); |
52 | return 0; | 51 | return 0; |
53 | } | 52 | } |
54 | 53 | ||
55 | to[0] = 0; | 54 | to[0] = 0; |
56 | seed = to + 1; | 55 | seed = to + 1; |
@@ -59,9 +58,9 @@ int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen, | |||
59 | if (!EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL)) | 58 | if (!EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL)) |
60 | return 0; | 59 | return 0; |
61 | memset(db + SHA_DIGEST_LENGTH, 0, | 60 | memset(db + SHA_DIGEST_LENGTH, 0, |
62 | emlen - flen - 2 * SHA_DIGEST_LENGTH - 1); | 61 | emlen - flen - 2 * SHA_DIGEST_LENGTH - 1); |
63 | db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01; | 62 | db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01; |
64 | memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int) flen); | 63 | memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int)flen); |
65 | if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0) | 64 | if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0) |
66 | return 0; | 65 | return 0; |
67 | #ifdef PKCS_TESTVECT | 66 | #ifdef PKCS_TESTVECT |
@@ -71,65 +70,73 @@ int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen, | |||
71 | #endif | 70 | #endif |
72 | 71 | ||
73 | dbmask = malloc(emlen - SHA_DIGEST_LENGTH); | 72 | dbmask = malloc(emlen - SHA_DIGEST_LENGTH); |
74 | if (dbmask == NULL) | 73 | if (dbmask == NULL) { |
75 | { | ||
76 | RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); | 74 | RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); |
77 | return 0; | 75 | return 0; |
78 | } | 76 | } |
79 | 77 | ||
80 | if (MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH) < 0) | 78 | if (MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, |
79 | SHA_DIGEST_LENGTH) < 0) | ||
81 | return 0; | 80 | return 0; |
82 | for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++) | 81 | for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++) |
83 | db[i] ^= dbmask[i]; | 82 | db[i] ^= dbmask[i]; |
84 | 83 | ||
85 | if (MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH) < 0) | 84 | if (MGF1(seedmask, SHA_DIGEST_LENGTH, db, |
85 | emlen - SHA_DIGEST_LENGTH) < 0) | ||
86 | return 0; | 86 | return 0; |
87 | for (i = 0; i < SHA_DIGEST_LENGTH; i++) | 87 | for (i = 0; i < SHA_DIGEST_LENGTH; i++) |
88 | seed[i] ^= seedmask[i]; | 88 | seed[i] ^= seedmask[i]; |
89 | 89 | ||
90 | free(dbmask); | 90 | free(dbmask); |
91 | return 1; | 91 | return 1; |
92 | } | 92 | } |
93 | 93 | ||
94 | int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, | 94 | int |
95 | const unsigned char *from, int flen, int num, | 95 | RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, |
96 | const unsigned char *param, int plen) | 96 | const unsigned char *from, int flen, int num, const unsigned char *param, |
97 | { | 97 | int plen) |
98 | { | ||
98 | int i, dblen, mlen = -1; | 99 | int i, dblen, mlen = -1; |
99 | const unsigned char *maskeddb; | 100 | const unsigned char *maskeddb; |
100 | int lzero; | 101 | int lzero; |
101 | unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH]; | 102 | unsigned char *db = NULL; |
103 | unsigned char seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH]; | ||
102 | unsigned char *padded_from; | 104 | unsigned char *padded_from; |
103 | int bad = 0; | 105 | int bad = 0; |
104 | 106 | ||
105 | if (--num < 2 * SHA_DIGEST_LENGTH + 1) | 107 | if (--num < 2 * SHA_DIGEST_LENGTH + 1) |
106 | /* 'num' is the length of the modulus, i.e. does not depend on the | 108 | /* |
107 | * particular ciphertext. */ | 109 | * 'num' is the length of the modulus, i.e. does not depend |
110 | * on the particular ciphertext. | ||
111 | */ | ||
108 | goto decoding_err; | 112 | goto decoding_err; |
109 | 113 | ||
110 | lzero = num - flen; | 114 | lzero = num - flen; |
111 | if (lzero < 0) | 115 | if (lzero < 0) { |
112 | { | 116 | /* |
113 | /* signalling this error immediately after detection might allow | 117 | * signalling this error immediately after detection might allow |
114 | * for side-channel attacks (e.g. timing if 'plen' is huge | 118 | * for side-channel attacks (e.g. timing if 'plen' is huge |
115 | * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA Optimal | 119 | * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA |
116 | * Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001), | 120 | * Optimal Asymmetric Encryption Padding (OAEP) [...]", |
117 | * so we use a 'bad' flag */ | 121 | * CRYPTO 2001), so we use a 'bad' flag |
122 | */ | ||
118 | bad = 1; | 123 | bad = 1; |
119 | lzero = 0; | 124 | lzero = 0; |
120 | flen = num; /* don't overflow the memcpy to padded_from */ | 125 | flen = num; /* don't overflow the memcpy to padded_from */ |
121 | } | 126 | } |
122 | 127 | ||
123 | dblen = num - SHA_DIGEST_LENGTH; | 128 | dblen = num - SHA_DIGEST_LENGTH; |
124 | db = malloc(dblen + num); | 129 | db = malloc(dblen + num); |
125 | if (db == NULL) | 130 | if (db == NULL) { |
126 | { | 131 | RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, |
127 | RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); | 132 | ERR_R_MALLOC_FAILURE); |
128 | return -1; | 133 | return -1; |
129 | } | 134 | } |
130 | 135 | ||
131 | /* Always do this zero-padding copy (even when lzero == 0) | 136 | /* |
132 | * to avoid leaking timing info about the value of lzero. */ | 137 | * Always do this zero-padding copy (even when lzero == 0) |
138 | * to avoid leaking timing info about the value of lzero. | ||
139 | */ | ||
133 | padded_from = db + dblen; | 140 | padded_from = db + dblen; |
134 | memset(padded_from, 0, lzero); | 141 | memset(padded_from, 0, lzero); |
135 | memcpy(padded_from + lzero, from, flen); | 142 | memcpy(padded_from + lzero, from, flen); |
@@ -151,41 +158,41 @@ int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, | |||
151 | 158 | ||
152 | if (CRYPTO_memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad) | 159 | if (CRYPTO_memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad) |
153 | goto decoding_err; | 160 | goto decoding_err; |
154 | else | 161 | else { |
155 | { | ||
156 | for (i = SHA_DIGEST_LENGTH; i < dblen; i++) | 162 | for (i = SHA_DIGEST_LENGTH; i < dblen; i++) |
157 | if (db[i] != 0x00) | 163 | if (db[i] != 0x00) |
158 | break; | 164 | break; |
159 | if (i == dblen || db[i] != 0x01) | 165 | if (i == dblen || db[i] != 0x01) |
160 | goto decoding_err; | 166 | goto decoding_err; |
161 | else | 167 | else { |
162 | { | ||
163 | /* everything looks OK */ | 168 | /* everything looks OK */ |
164 | 169 | ||
165 | mlen = dblen - ++i; | 170 | mlen = dblen - ++i; |
166 | if (tlen < mlen) | 171 | if (tlen < mlen) { |
167 | { | 172 | RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, |
168 | RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE); | 173 | RSA_R_DATA_TOO_LARGE); |
169 | mlen = -1; | 174 | mlen = -1; |
170 | } | 175 | } else |
171 | else | ||
172 | memcpy(to, db + i, mlen); | 176 | memcpy(to, db + i, mlen); |
173 | } | ||
174 | } | 177 | } |
178 | } | ||
175 | free(db); | 179 | free(db); |
176 | return mlen; | 180 | return mlen; |
177 | 181 | ||
178 | decoding_err: | 182 | decoding_err: |
179 | /* to avoid chosen ciphertext attacks, the error message should not reveal | 183 | /* |
180 | * which kind of decoding error happened */ | 184 | * To avoid chosen ciphertext attacks, the error message should not |
185 | * reveal which kind of decoding error happened | ||
186 | */ | ||
181 | RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); | 187 | RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); |
182 | free(db); | 188 | free(db); |
183 | return -1; | 189 | return -1; |
184 | } | 190 | } |
185 | 191 | ||
186 | int PKCS1_MGF1(unsigned char *mask, long len, | 192 | int |
187 | const unsigned char *seed, long seedlen, const EVP_MD *dgst) | 193 | PKCS1_MGF1(unsigned char *mask, long len, const unsigned char *seed, |
188 | { | 194 | long seedlen, const EVP_MD *dgst) |
195 | { | ||
189 | long i, outlen = 0; | 196 | long i, outlen = 0; |
190 | unsigned char cnt[4]; | 197 | unsigned char cnt[4]; |
191 | EVP_MD_CTX c; | 198 | EVP_MD_CTX c; |
@@ -197,39 +204,35 @@ int PKCS1_MGF1(unsigned char *mask, long len, | |||
197 | mdlen = EVP_MD_size(dgst); | 204 | mdlen = EVP_MD_size(dgst); |
198 | if (mdlen < 0) | 205 | if (mdlen < 0) |
199 | goto err; | 206 | goto err; |
200 | for (i = 0; outlen < len; i++) | 207 | for (i = 0; outlen < len; i++) { |
201 | { | ||
202 | cnt[0] = (unsigned char)((i >> 24) & 255); | 208 | cnt[0] = (unsigned char)((i >> 24) & 255); |
203 | cnt[1] = (unsigned char)((i >> 16) & 255); | 209 | cnt[1] = (unsigned char)((i >> 16) & 255); |
204 | cnt[2] = (unsigned char)((i >> 8)) & 255; | 210 | cnt[2] = (unsigned char)((i >> 8)) & 255; |
205 | cnt[3] = (unsigned char)(i & 255); | 211 | cnt[3] = (unsigned char)(i & 255); |
206 | if (!EVP_DigestInit_ex(&c,dgst, NULL) | 212 | if (!EVP_DigestInit_ex(&c,dgst, NULL) || |
207 | || !EVP_DigestUpdate(&c, seed, seedlen) | 213 | !EVP_DigestUpdate(&c, seed, seedlen) || |
208 | || !EVP_DigestUpdate(&c, cnt, 4)) | 214 | !EVP_DigestUpdate(&c, cnt, 4)) |
209 | goto err; | 215 | goto err; |
210 | if (outlen + mdlen <= len) | 216 | if (outlen + mdlen <= len) { |
211 | { | ||
212 | if (!EVP_DigestFinal_ex(&c, mask + outlen, NULL)) | 217 | if (!EVP_DigestFinal_ex(&c, mask + outlen, NULL)) |
213 | goto err; | 218 | goto err; |
214 | outlen += mdlen; | 219 | outlen += mdlen; |
215 | } | 220 | } else { |
216 | else | ||
217 | { | ||
218 | if (!EVP_DigestFinal_ex(&c, md, NULL)) | 221 | if (!EVP_DigestFinal_ex(&c, md, NULL)) |
219 | goto err; | 222 | goto err; |
220 | memcpy(mask + outlen, md, len - outlen); | 223 | memcpy(mask + outlen, md, len - outlen); |
221 | outlen = len; | 224 | outlen = len; |
222 | } | ||
223 | } | 225 | } |
226 | } | ||
224 | rv = 0; | 227 | rv = 0; |
225 | err: | 228 | err: |
226 | EVP_MD_CTX_cleanup(&c); | 229 | EVP_MD_CTX_cleanup(&c); |
227 | return rv; | 230 | return rv; |
228 | } | 231 | } |
229 | 232 | ||
230 | static int MGF1(unsigned char *mask, long len, const unsigned char *seed, | 233 | static int |
231 | long seedlen) | 234 | MGF1(unsigned char *mask, long len, const unsigned char *seed, long seedlen) |
232 | { | 235 | { |
233 | return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1()); | 236 | return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1()); |
234 | } | 237 | } |
235 | #endif | 238 | #endif |