Blame view
lib/digsig.c
5.51 KB
b886d83c5 treewide: Replace... |
1 |
// SPDX-License-Identifier: GPL-2.0-only |
051dbb918 crypto: digital s... |
2 3 4 5 6 7 8 9 |
/* * Copyright (C) 2011 Nokia Corporation * Copyright (C) 2011 Intel Corporation * * Author: * Dmitry Kasatkin <dmitry.kasatkin@nokia.com> * <dmitry.kasatkin@intel.com> * |
051dbb918 crypto: digital s... |
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 |
* File: sign.c * implements signature (RSA) verification * pkcs decoding is based on LibTomCrypt code */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/err.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/key.h> #include <linux/crypto.h> #include <crypto/hash.h> #include <crypto/sha.h> #include <keys/user-type.h> #include <linux/mpi.h> #include <linux/digsig.h> static struct crypto_shash *shash; |
26d438457 digsig: remove un... |
29 30 31 32 |
static const char *pkcs_1_v1_5_decode_emsa(const unsigned char *msg, unsigned long msglen, unsigned long modulus_bitlen, unsigned long *outlen) |
051dbb918 crypto: digital s... |
33 34 |
{ unsigned long modulus_len, ps_len, i; |
051dbb918 crypto: digital s... |
35 36 37 38 39 |
modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0); /* test message size */ if ((msglen > modulus_len) || (modulus_len < 11)) |
26d438457 digsig: remove un... |
40 |
return NULL; |
051dbb918 crypto: digital s... |
41 42 |
/* separate encoded message */ |
26d438457 digsig: remove un... |
43 44 |
if (msg[0] != 0x00 || msg[1] != 0x01) return NULL; |
051dbb918 crypto: digital s... |
45 46 47 48 49 50 |
for (i = 2; i < modulus_len - 1; i++) if (msg[i] != 0xFF) break; /* separator check */ |
b35e286a6 lib/digsig: pkcs_... |
51 |
if (msg[i] != 0) |
051dbb918 crypto: digital s... |
52 53 |
/* There was no octet with hexadecimal value 0x00 to separate ps from m. */ |
26d438457 digsig: remove un... |
54 |
return NULL; |
051dbb918 crypto: digital s... |
55 56 |
ps_len = i - 2; |
051dbb918 crypto: digital s... |
57 |
*outlen = (msglen - (2 + ps_len + 1)); |
051dbb918 crypto: digital s... |
58 |
|
26d438457 digsig: remove un... |
59 |
return msg + 2 + ps_len + 1; |
051dbb918 crypto: digital s... |
60 61 62 63 64 65 66 67 68 69 70 71 72 |
} /* * RSA Signature verification with public key */ static int digsig_verify_rsa(struct key *key, const char *sig, int siglen, const char *h, int hlen) { int err = -EINVAL; unsigned long len; unsigned long mlen, mblen; unsigned nret, l; |
b35e286a6 lib/digsig: pkcs_... |
73 |
int head, i; |
26d438457 digsig: remove un... |
74 75 |
unsigned char *out1 = NULL; const char *m; |
051dbb918 crypto: digital s... |
76 |
MPI in = NULL, res = NULL, pkey[2]; |
146aa8b14 KEYS: Merge the t... |
77 78 79 |
uint8_t *p, *datap; const uint8_t *endp; const struct user_key_payload *ukp; |
051dbb918 crypto: digital s... |
80 81 82 |
struct pubkey_hdr *pkh; down_read(&key->sem); |
0837e49ab KEYS: Differentia... |
83 |
ukp = user_key_payload_locked(key); |
f58a08152 lib/digsig: addit... |
84 |
|
192cabd6a lib/digsig: fix d... |
85 86 87 88 89 |
if (!ukp) { /* key was revoked before we acquired its semaphore */ err = -EKEYREVOKED; goto err1; } |
f58a08152 lib/digsig: addit... |
90 91 |
if (ukp->datalen < sizeof(*pkh)) goto err1; |
051dbb918 crypto: digital s... |
92 93 94 95 96 97 98 99 100 101 102 103 |
pkh = (struct pubkey_hdr *)ukp->data; if (pkh->version != 1) goto err1; if (pkh->algo != PUBKEY_ALGO_RSA) goto err1; if (pkh->nmpi != 2) goto err1; datap = pkh->mpi; |
f58a08152 lib/digsig: addit... |
104 |
endp = ukp->data + ukp->datalen; |
051dbb918 crypto: digital s... |
105 106 107 108 |
for (i = 0; i < pkh->nmpi; i++) { unsigned int remaining = endp - datap; pkey[i] = mpi_read_from_buffer(datap, &remaining); |
03cdfaad4 lib/mpi: mpi_read... |
109 110 |
if (IS_ERR(pkey[i])) { err = PTR_ERR(pkey[i]); |
86f8bedc9 lib/digsig: check... |
111 |
goto err; |
03cdfaad4 lib/mpi: mpi_read... |
112 |
} |
051dbb918 crypto: digital s... |
113 114 115 116 |
datap += remaining; } mblen = mpi_get_nbits(pkey[0]); |
26d438457 digsig: remove un... |
117 |
mlen = DIV_ROUND_UP(mblen, 8); |
051dbb918 crypto: digital s... |
118 |
|
c5ce7c697 lib/digsig: digsi... |
119 120 |
if (mlen == 0) { err = -EINVAL; |
f58a08152 lib/digsig: addit... |
121 |
goto err; |
c5ce7c697 lib/digsig: digsi... |
122 123 124 |
} err = -ENOMEM; |
051dbb918 crypto: digital s... |
125 126 127 128 |
out1 = kzalloc(mlen, GFP_KERNEL); if (!out1) goto err; |
051dbb918 crypto: digital s... |
129 130 |
nret = siglen; in = mpi_read_from_buffer(sig, &nret); |
03cdfaad4 lib/mpi: mpi_read... |
131 132 |
if (IS_ERR(in)) { err = PTR_ERR(in); |
051dbb918 crypto: digital s... |
133 |
goto err; |
03cdfaad4 lib/mpi: mpi_read... |
134 |
} |
051dbb918 crypto: digital s... |
135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 |
res = mpi_alloc(mpi_get_nlimbs(in) * 2); if (!res) goto err; err = mpi_powm(res, in, pkey[1], pkey[0]); if (err) goto err; if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) { err = -EINVAL; goto err; } p = mpi_get_buffer(res, &l, NULL); if (!p) { err = -EINVAL; goto err; } len = mlen; head = len - l; memset(out1, 0, head); memcpy(out1 + head, p, l); |
7810cc1e7 digsig: Fix memor... |
159 |
kfree(p); |
26d438457 digsig: remove un... |
160 |
m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len); |
051dbb918 crypto: digital s... |
161 |
|
26d438457 digsig: remove un... |
162 |
if (!m || len != hlen || memcmp(m, h, hlen)) |
bc01637a8 digsig: add hash ... |
163 |
err = -EINVAL; |
051dbb918 crypto: digital s... |
164 165 166 167 168 |
err: mpi_free(in); mpi_free(res); kfree(out1); |
86f8bedc9 lib/digsig: check... |
169 170 |
while (--i >= 0) mpi_free(pkey[i]); |
051dbb918 crypto: digital s... |
171 172 173 174 175 176 177 178 179 180 |
err1: up_read(&key->sem); return err; } /** * digsig_verify() - digital signature verification with public key * @keyring: keyring to search key in * @sig: digital signature |
54b14f40c lib/digsig.c: ker... |
181 |
* @siglen: length of the signature |
051dbb918 crypto: digital s... |
182 183 |
* @data: data * @datalen: length of the data |
54b14f40c lib/digsig.c: ker... |
184 185 |
* * Returns 0 on success, -EINVAL otherwise |
051dbb918 crypto: digital s... |
186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 |
* * Verifies data integrity against digital signature. * Currently only RSA is supported. * Normally hash of the content is used as a data for this function. * */ int digsig_verify(struct key *keyring, const char *sig, int siglen, const char *data, int datalen) { int err = -ENOMEM; struct signature_hdr *sh = (struct signature_hdr *)sig; struct shash_desc *desc = NULL; unsigned char hash[SHA1_DIGEST_SIZE]; struct key *key; char name[20]; if (siglen < sizeof(*sh) + 2) return -EINVAL; if (sh->algo != PUBKEY_ALGO_RSA) return -ENOTSUPP; sprintf(name, "%llX", __be64_to_cpup((uint64_t *)sh->keyid)); if (keyring) { /* search in specific keyring */ key_ref_t kref; kref = keyring_search(make_key_ref(keyring, 1UL), |
dcf49dbc8 keys: Add a 'recu... |
214 |
&key_type_user, name, true); |
051dbb918 crypto: digital s... |
215 |
if (IS_ERR(kref)) |
ff6092a8a lib/digsig.c: use... |
216 |
key = ERR_CAST(kref); |
051dbb918 crypto: digital s... |
217 218 219 |
else key = key_ref_to_ptr(kref); } else { |
028db3e29 Revert "Merge tag... |
220 |
key = request_key(&key_type_user, name, NULL); |
051dbb918 crypto: digital s... |
221 222 223 224 225 226 227 228 229 230 231 232 233 |
} if (IS_ERR(key)) { pr_err("key not found, id: %s ", name); return PTR_ERR(key); } desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(shash), GFP_KERNEL); if (!desc) goto err; desc->tfm = shash; |
051dbb918 crypto: digital s... |
234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 |
crypto_shash_init(desc); crypto_shash_update(desc, data, datalen); crypto_shash_update(desc, sig, sizeof(*sh)); crypto_shash_final(desc, hash); kfree(desc); /* pass signature mpis address */ err = digsig_verify_rsa(key, sig + sizeof(*sh), siglen - sizeof(*sh), hash, sizeof(hash)); err: key_put(key); return err ? -EINVAL : 0; } EXPORT_SYMBOL_GPL(digsig_verify); static int __init digsig_init(void) { shash = crypto_alloc_shash("sha1", 0, 0); if (IS_ERR(shash)) { pr_err("shash allocation failed "); return PTR_ERR(shash); } return 0; } static void __exit digsig_cleanup(void) { crypto_free_shash(shash); } module_init(digsig_init); module_exit(digsig_cleanup); MODULE_LICENSE("GPL"); |