1 /*
2 * Copyright 2009-2024 The OpenSSL Project Authors. All Rights Reserved.
3 *
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
8 */
9
10 #include "internal/cryptlib.h"
11 #include <openssl/asn1t.h>
12 #include <openssl/pem.h>
13 #include <openssl/x509v3.h>
14 #include <openssl/err.h>
15 #include <openssl/cms.h>
16 #include <openssl/rand.h>
17 #include <openssl/aes.h>
18 #include "internal/sizes.h"
19 #include "crypto/asn1.h"
20 #include "cms_local.h"
21
CMS_RecipientInfo_set0_password(CMS_RecipientInfo * ri,unsigned char * pass,ossl_ssize_t passlen)22 int CMS_RecipientInfo_set0_password(CMS_RecipientInfo *ri,
23 unsigned char *pass, ossl_ssize_t passlen)
24 {
25 CMS_PasswordRecipientInfo *pwri;
26 if (ri->type != CMS_RECIPINFO_PASS) {
27 ERR_raise(ERR_LIB_CMS, CMS_R_NOT_PWRI);
28 return 0;
29 }
30
31 pwri = ri->d.pwri;
32 pwri->pass = pass;
33 if (pass && passlen < 0)
34 passlen = strlen((char *)pass);
35 pwri->passlen = passlen;
36 return 1;
37 }
38
CMS_add0_recipient_password(CMS_ContentInfo * cms,int iter,int wrap_nid,int pbe_nid,unsigned char * pass,ossl_ssize_t passlen,const EVP_CIPHER * kekciph)39 CMS_RecipientInfo *CMS_add0_recipient_password(CMS_ContentInfo *cms,
40 int iter, int wrap_nid,
41 int pbe_nid,
42 unsigned char *pass,
43 ossl_ssize_t passlen,
44 const EVP_CIPHER *kekciph)
45 {
46 STACK_OF(CMS_RecipientInfo) *ris;
47 CMS_RecipientInfo *ri = NULL;
48 CMS_EncryptedContentInfo *ec;
49 CMS_PasswordRecipientInfo *pwri;
50 EVP_CIPHER_CTX *ctx = NULL;
51 X509_ALGOR *encalg = NULL;
52 unsigned char iv[EVP_MAX_IV_LENGTH];
53 int ivlen;
54 const CMS_CTX *cms_ctx = ossl_cms_get0_cmsctx(cms);
55
56 ec = ossl_cms_get0_env_enc_content(cms);
57 if (ec == NULL)
58 return NULL;
59 ris = CMS_get0_RecipientInfos(cms);
60 if (ris == NULL)
61 return NULL;
62
63 if (wrap_nid <= 0)
64 wrap_nid = NID_id_alg_PWRI_KEK;
65
66 if (pbe_nid <= 0)
67 pbe_nid = NID_id_pbkdf2;
68
69 /* Get from enveloped data */
70 if (kekciph == NULL)
71 kekciph = ec->cipher;
72
73 if (kekciph == NULL) {
74 ERR_raise(ERR_LIB_CMS, CMS_R_NO_CIPHER);
75 return NULL;
76 }
77 if (wrap_nid != NID_id_alg_PWRI_KEK) {
78 ERR_raise(ERR_LIB_CMS, CMS_R_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM);
79 return NULL;
80 }
81
82 /* Setup algorithm identifier for cipher */
83 encalg = X509_ALGOR_new();
84 if (encalg == NULL) {
85 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
86 goto err;
87 }
88 ctx = EVP_CIPHER_CTX_new();
89 if (ctx == NULL) {
90 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
91 goto err;
92 }
93
94 if (EVP_EncryptInit_ex(ctx, kekciph, NULL, NULL, NULL) <= 0) {
95 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
96 goto err;
97 }
98
99 ivlen = EVP_CIPHER_CTX_get_iv_length(ctx);
100 if (ivlen < 0) {
101 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
102 goto err;
103 }
104
105 if (ivlen > 0) {
106 if (RAND_bytes_ex(ossl_cms_ctx_get0_libctx(cms_ctx), iv, ivlen, 0) <= 0)
107 goto err;
108 if (EVP_EncryptInit_ex(ctx, NULL, NULL, NULL, iv) <= 0) {
109 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
110 goto err;
111 }
112 encalg->parameter = ASN1_TYPE_new();
113 if (!encalg->parameter) {
114 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
115 goto err;
116 }
117 if (EVP_CIPHER_param_to_asn1(ctx, encalg->parameter) <= 0) {
118 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
119 goto err;
120 }
121 }
122
123 encalg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_get_type(ctx));
124
125 EVP_CIPHER_CTX_free(ctx);
126 ctx = NULL;
127
128 /* Initialize recipient info */
129 ri = M_ASN1_new_of(CMS_RecipientInfo);
130 if (ri == NULL) {
131 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
132 goto err;
133 }
134
135 ri->d.pwri = M_ASN1_new_of(CMS_PasswordRecipientInfo);
136 if (ri->d.pwri == NULL) {
137 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
138 goto err;
139 }
140 ri->type = CMS_RECIPINFO_PASS;
141
142 pwri = ri->d.pwri;
143 pwri->cms_ctx = cms_ctx;
144 /* Since this is overwritten, free up empty structure already there */
145 X509_ALGOR_free(pwri->keyEncryptionAlgorithm);
146 pwri->keyEncryptionAlgorithm = X509_ALGOR_new();
147 if (pwri->keyEncryptionAlgorithm == NULL) {
148 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
149 goto err;
150 }
151 pwri->keyEncryptionAlgorithm->algorithm = OBJ_nid2obj(wrap_nid);
152 pwri->keyEncryptionAlgorithm->parameter = ASN1_TYPE_new();
153 if (pwri->keyEncryptionAlgorithm->parameter == NULL) {
154 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
155 goto err;
156 }
157
158 if (!ASN1_item_pack(encalg, ASN1_ITEM_rptr(X509_ALGOR),
159 &pwri->keyEncryptionAlgorithm->parameter->
160 value.sequence)) {
161 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
162 goto err;
163 }
164 pwri->keyEncryptionAlgorithm->parameter->type = V_ASN1_SEQUENCE;
165
166 X509_ALGOR_free(encalg);
167 encalg = NULL;
168
169 /* Setup PBE algorithm */
170
171 pwri->keyDerivationAlgorithm = PKCS5_pbkdf2_set(iter, NULL, 0, -1, -1);
172
173 if (pwri->keyDerivationAlgorithm == NULL)
174 goto err;
175
176 CMS_RecipientInfo_set0_password(ri, pass, passlen);
177 pwri->version = 0;
178
179 if (!sk_CMS_RecipientInfo_push(ris, ri)) {
180 ERR_raise(ERR_LIB_CMS, ERR_R_CRYPTO_LIB);
181 goto err;
182 }
183
184 return ri;
185
186 err:
187 EVP_CIPHER_CTX_free(ctx);
188 if (ri)
189 M_ASN1_free_of(ri, CMS_RecipientInfo);
190 X509_ALGOR_free(encalg);
191 return NULL;
192
193 }
194
195 /*
196 * This is an implementation of the key wrapping mechanism in RFC3211, at
197 * some point this should go into EVP.
198 */
199
kek_unwrap_key(unsigned char * out,size_t * outlen,const unsigned char * in,size_t inlen,EVP_CIPHER_CTX * ctx)200 static int kek_unwrap_key(unsigned char *out, size_t *outlen,
201 const unsigned char *in, size_t inlen,
202 EVP_CIPHER_CTX *ctx)
203 {
204 size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
205 unsigned char *tmp;
206 int outl, rv = 0;
207
208 if (blocklen == 0)
209 return 0;
210
211 if (inlen < 2 * blocklen) {
212 /* too small */
213 return 0;
214 }
215 if (inlen % blocklen) {
216 /* Invalid size */
217 return 0;
218 }
219 if ((tmp = OPENSSL_malloc(inlen)) == NULL)
220 return 0;
221 /* setup IV by decrypting last two blocks */
222 if (!EVP_DecryptUpdate(ctx, tmp + inlen - 2 * blocklen, &outl,
223 in + inlen - 2 * blocklen, blocklen * 2)
224 /*
225 * Do a decrypt of last decrypted block to set IV to correct value
226 * output it to start of buffer so we don't corrupt decrypted block
227 * this works because buffer is at least two block lengths long.
228 */
229 || !EVP_DecryptUpdate(ctx, tmp, &outl,
230 tmp + inlen - blocklen, blocklen)
231 /* Can now decrypt first n - 1 blocks */
232 || !EVP_DecryptUpdate(ctx, tmp, &outl, in, inlen - blocklen)
233
234 /* Reset IV to original value */
235 || !EVP_DecryptInit_ex(ctx, NULL, NULL, NULL, NULL)
236 /* Decrypt again */
237 || !EVP_DecryptUpdate(ctx, tmp, &outl, tmp, inlen))
238 goto err;
239 /* Check check bytes */
240 if (((tmp[1] ^ tmp[4]) & (tmp[2] ^ tmp[5]) & (tmp[3] ^ tmp[6])) != 0xff) {
241 /* Check byte failure */
242 goto err;
243 }
244 if (inlen < (size_t)(tmp[0] - 4)) {
245 /* Invalid length value */
246 goto err;
247 }
248 *outlen = (size_t)tmp[0];
249 memcpy(out, tmp + 4, *outlen);
250 rv = 1;
251 err:
252 OPENSSL_clear_free(tmp, inlen);
253 return rv;
254
255 }
256
kek_wrap_key(unsigned char * out,size_t * outlen,const unsigned char * in,size_t inlen,EVP_CIPHER_CTX * ctx,const CMS_CTX * cms_ctx)257 static int kek_wrap_key(unsigned char *out, size_t *outlen,
258 const unsigned char *in, size_t inlen,
259 EVP_CIPHER_CTX *ctx, const CMS_CTX *cms_ctx)
260 {
261 size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
262 size_t olen;
263 int dummy;
264
265 if (blocklen == 0)
266 return 0;
267
268 /*
269 * First decide length of output buffer: need header and round up to
270 * multiple of block length.
271 */
272 olen = (inlen + 4 + blocklen - 1) / blocklen;
273 olen *= blocklen;
274 if (olen < 2 * blocklen) {
275 /* Key too small */
276 return 0;
277 }
278 if (inlen > 0xFF) {
279 /* Key too large */
280 return 0;
281 }
282 if (out) {
283 /* Set header */
284 out[0] = (unsigned char)inlen;
285 out[1] = in[0] ^ 0xFF;
286 out[2] = in[1] ^ 0xFF;
287 out[3] = in[2] ^ 0xFF;
288 memcpy(out + 4, in, inlen);
289 /* Add random padding to end */
290 if (olen > inlen + 4
291 && RAND_bytes_ex(ossl_cms_ctx_get0_libctx(cms_ctx), out + 4 + inlen,
292 olen - 4 - inlen, 0) <= 0)
293 return 0;
294 /* Encrypt twice */
295 if (!EVP_EncryptUpdate(ctx, out, &dummy, out, olen)
296 || !EVP_EncryptUpdate(ctx, out, &dummy, out, olen))
297 return 0;
298 }
299
300 *outlen = olen;
301
302 return 1;
303 }
304
305 /* Encrypt/Decrypt content key in PWRI recipient info */
306
ossl_cms_RecipientInfo_pwri_crypt(const CMS_ContentInfo * cms,CMS_RecipientInfo * ri,int en_de)307 int ossl_cms_RecipientInfo_pwri_crypt(const CMS_ContentInfo *cms,
308 CMS_RecipientInfo *ri, int en_de)
309 {
310 CMS_EncryptedContentInfo *ec;
311 CMS_PasswordRecipientInfo *pwri;
312 int r = 0;
313 X509_ALGOR *algtmp, *kekalg = NULL;
314 EVP_CIPHER_CTX *kekctx = NULL;
315 char name[OSSL_MAX_NAME_SIZE];
316 EVP_CIPHER *kekcipher;
317 unsigned char *key = NULL;
318 size_t keylen;
319 const CMS_CTX *cms_ctx = ossl_cms_get0_cmsctx(cms);
320
321 ec = ossl_cms_get0_env_enc_content(cms);
322
323 pwri = ri->d.pwri;
324
325 if (pwri->pass == NULL) {
326 ERR_raise(ERR_LIB_CMS, CMS_R_NO_PASSWORD);
327 return 0;
328 }
329 algtmp = pwri->keyEncryptionAlgorithm;
330
331 if (!algtmp || OBJ_obj2nid(algtmp->algorithm) != NID_id_alg_PWRI_KEK) {
332 ERR_raise(ERR_LIB_CMS, CMS_R_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM);
333 return 0;
334 }
335
336 kekalg = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(X509_ALGOR),
337 algtmp->parameter);
338
339 if (kekalg == NULL) {
340 ERR_raise(ERR_LIB_CMS, CMS_R_INVALID_KEY_ENCRYPTION_PARAMETER);
341 return 0;
342 }
343
344 OBJ_obj2txt(name, sizeof(name), kekalg->algorithm, 0);
345 kekcipher = EVP_CIPHER_fetch(ossl_cms_ctx_get0_libctx(cms_ctx), name,
346 ossl_cms_ctx_get0_propq(cms_ctx));
347
348 if (kekcipher == NULL) {
349 ERR_raise(ERR_LIB_CMS, CMS_R_UNKNOWN_CIPHER);
350 goto err;
351 }
352
353 kekctx = EVP_CIPHER_CTX_new();
354 if (kekctx == NULL) {
355 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
356 goto err;
357 }
358 /* Fixup cipher based on AlgorithmIdentifier to set IV etc */
359 if (!EVP_CipherInit_ex(kekctx, kekcipher, NULL, NULL, NULL, en_de))
360 goto err;
361 EVP_CIPHER_CTX_set_padding(kekctx, 0);
362 if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0) {
363 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
364 goto err;
365 }
366
367 algtmp = pwri->keyDerivationAlgorithm;
368
369 /* Finish password based key derivation to setup key in "ctx" */
370
371 if (EVP_PBE_CipherInit(algtmp->algorithm,
372 (char *)pwri->pass, pwri->passlen,
373 algtmp->parameter, kekctx, en_de) < 0) {
374 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
375 goto err;
376 }
377
378 /* Finally wrap/unwrap the key */
379
380 if (en_de) {
381
382 if (!kek_wrap_key(NULL, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
383 goto err;
384
385 key = OPENSSL_malloc(keylen);
386
387 if (key == NULL)
388 goto err;
389
390 if (!kek_wrap_key(key, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
391 goto err;
392 pwri->encryptedKey->data = key;
393 pwri->encryptedKey->length = keylen;
394 } else {
395 key = OPENSSL_malloc(pwri->encryptedKey->length);
396 if (key == NULL)
397 goto err;
398 if (!kek_unwrap_key(key, &keylen,
399 pwri->encryptedKey->data,
400 pwri->encryptedKey->length, kekctx)) {
401 ERR_raise(ERR_LIB_CMS, CMS_R_UNWRAP_FAILURE);
402 goto err;
403 }
404
405 OPENSSL_clear_free(ec->key, ec->keylen);
406 ec->key = key;
407 ec->keylen = keylen;
408
409 }
410
411 r = 1;
412
413 err:
414 EVP_CIPHER_free(kekcipher);
415 EVP_CIPHER_CTX_free(kekctx);
416
417 if (!r)
418 OPENSSL_free(key);
419 X509_ALGOR_free(kekalg);
420
421 return r;
422
423 }
424
