1 /*
2 * Copyright 2009-2025 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_ex(iter, NULL, 0, -1, -1,
172 cms_ctx->libctx);
173
174 if (pwri->keyDerivationAlgorithm == NULL)
175 goto err;
176
177 CMS_RecipientInfo_set0_password(ri, pass, passlen);
178 pwri->version = 0;
179
180 if (!sk_CMS_RecipientInfo_push(ris, ri)) {
181 ERR_raise(ERR_LIB_CMS, ERR_R_CRYPTO_LIB);
182 goto err;
183 }
184
185 return ri;
186
187 err:
188 EVP_CIPHER_CTX_free(ctx);
189 if (ri)
190 M_ASN1_free_of(ri, CMS_RecipientInfo);
191 X509_ALGOR_free(encalg);
192 return NULL;
193
194 }
195
196 /*
197 * This is an implementation of the key wrapping mechanism in RFC3211, at
198 * some point this should go into EVP.
199 */
200
kek_unwrap_key(unsigned char * out,size_t * outlen,const unsigned char * in,size_t inlen,EVP_CIPHER_CTX * ctx)201 static int kek_unwrap_key(unsigned char *out, size_t *outlen,
202 const unsigned char *in, size_t inlen,
203 EVP_CIPHER_CTX *ctx)
204 {
205 size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
206 unsigned char *tmp;
207 int outl, rv = 0;
208
209 if (blocklen == 0)
210 return 0;
211
212 if (inlen < 2 * blocklen) {
213 /* too small */
214 return 0;
215 }
216 if (inlen % blocklen) {
217 /* Invalid size */
218 return 0;
219 }
220 if ((tmp = OPENSSL_malloc(inlen)) == NULL)
221 return 0;
222 /* setup IV by decrypting last two blocks */
223 if (!EVP_DecryptUpdate(ctx, tmp + inlen - 2 * blocklen, &outl,
224 in + inlen - 2 * blocklen, blocklen * 2)
225 /*
226 * Do a decrypt of last decrypted block to set IV to correct value
227 * output it to start of buffer so we don't corrupt decrypted block
228 * this works because buffer is at least two block lengths long.
229 */
230 || !EVP_DecryptUpdate(ctx, tmp, &outl,
231 tmp + inlen - blocklen, blocklen)
232 /* Can now decrypt first n - 1 blocks */
233 || !EVP_DecryptUpdate(ctx, tmp, &outl, in, inlen - blocklen)
234
235 /* Reset IV to original value */
236 || !EVP_DecryptInit_ex(ctx, NULL, NULL, NULL, NULL)
237 /* Decrypt again */
238 || !EVP_DecryptUpdate(ctx, tmp, &outl, tmp, inlen))
239 goto err;
240 /* Check check bytes */
241 if (((tmp[1] ^ tmp[4]) & (tmp[2] ^ tmp[5]) & (tmp[3] ^ tmp[6])) != 0xff) {
242 /* Check byte failure */
243 goto err;
244 }
245 if (inlen < (size_t)(tmp[0] - 4)) {
246 /* Invalid length value */
247 goto err;
248 }
249 *outlen = (size_t)tmp[0];
250 memcpy(out, tmp + 4, *outlen);
251 rv = 1;
252 err:
253 OPENSSL_clear_free(tmp, inlen);
254 return rv;
255
256 }
257
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)258 static int kek_wrap_key(unsigned char *out, size_t *outlen,
259 const unsigned char *in, size_t inlen,
260 EVP_CIPHER_CTX *ctx, const CMS_CTX *cms_ctx)
261 {
262 size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
263 size_t olen;
264 int dummy;
265
266 if (blocklen == 0)
267 return 0;
268
269 /*
270 * First decide length of output buffer: need header and round up to
271 * multiple of block length.
272 */
273 olen = (inlen + 4 + blocklen - 1) / blocklen;
274 olen *= blocklen;
275 if (olen < 2 * blocklen) {
276 /* Key too small */
277 return 0;
278 }
279 if (inlen > 0xFF) {
280 /* Key too large */
281 return 0;
282 }
283 if (out) {
284 /* Set header */
285 out[0] = (unsigned char)inlen;
286 out[1] = in[0] ^ 0xFF;
287 out[2] = in[1] ^ 0xFF;
288 out[3] = in[2] ^ 0xFF;
289 memcpy(out + 4, in, inlen);
290 /* Add random padding to end */
291 if (olen > inlen + 4
292 && RAND_bytes_ex(ossl_cms_ctx_get0_libctx(cms_ctx), out + 4 + inlen,
293 olen - 4 - inlen, 0) <= 0)
294 return 0;
295 /* Encrypt twice */
296 if (!EVP_EncryptUpdate(ctx, out, &dummy, out, olen)
297 || !EVP_EncryptUpdate(ctx, out, &dummy, out, olen))
298 return 0;
299 }
300
301 *outlen = olen;
302
303 return 1;
304 }
305
306 /* Encrypt/Decrypt content key in PWRI recipient info */
307
ossl_cms_RecipientInfo_pwri_crypt(const CMS_ContentInfo * cms,CMS_RecipientInfo * ri,int en_de)308 int ossl_cms_RecipientInfo_pwri_crypt(const CMS_ContentInfo *cms,
309 CMS_RecipientInfo *ri, int en_de)
310 {
311 CMS_EncryptedContentInfo *ec;
312 CMS_PasswordRecipientInfo *pwri;
313 int r = 0;
314 X509_ALGOR *algtmp, *kekalg = NULL;
315 EVP_CIPHER_CTX *kekctx = NULL;
316 char name[OSSL_MAX_NAME_SIZE];
317 EVP_CIPHER *kekcipher;
318 unsigned char *key = NULL;
319 size_t keylen;
320 const CMS_CTX *cms_ctx = ossl_cms_get0_cmsctx(cms);
321
322 ec = ossl_cms_get0_env_enc_content(cms);
323
324 pwri = ri->d.pwri;
325
326 if (pwri->pass == NULL) {
327 ERR_raise(ERR_LIB_CMS, CMS_R_NO_PASSWORD);
328 return 0;
329 }
330 algtmp = pwri->keyEncryptionAlgorithm;
331
332 if (!algtmp || OBJ_obj2nid(algtmp->algorithm) != NID_id_alg_PWRI_KEK) {
333 ERR_raise(ERR_LIB_CMS, CMS_R_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM);
334 return 0;
335 }
336
337 kekalg = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(X509_ALGOR),
338 algtmp->parameter);
339
340 if (kekalg == NULL) {
341 ERR_raise(ERR_LIB_CMS, CMS_R_INVALID_KEY_ENCRYPTION_PARAMETER);
342 return 0;
343 }
344
345 OBJ_obj2txt(name, sizeof(name), kekalg->algorithm, 0);
346 kekcipher = EVP_CIPHER_fetch(ossl_cms_ctx_get0_libctx(cms_ctx), name,
347 ossl_cms_ctx_get0_propq(cms_ctx));
348
349 if (kekcipher == NULL) {
350 ERR_raise(ERR_LIB_CMS, CMS_R_UNKNOWN_CIPHER);
351 goto err;
352 }
353
354 kekctx = EVP_CIPHER_CTX_new();
355 if (kekctx == NULL) {
356 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
357 goto err;
358 }
359 /* Fixup cipher based on AlgorithmIdentifier to set IV etc */
360 if (!EVP_CipherInit_ex(kekctx, kekcipher, NULL, NULL, NULL, en_de))
361 goto err;
362 EVP_CIPHER_CTX_set_padding(kekctx, 0);
363 if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0) {
364 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
365 goto err;
366 }
367
368 algtmp = pwri->keyDerivationAlgorithm;
369
370 /* Finish password based key derivation to setup key in "ctx" */
371
372 if (EVP_PBE_CipherInit_ex(algtmp->algorithm,
373 (char *)pwri->pass, pwri->passlen,
374 algtmp->parameter, kekctx, en_de,
375 cms_ctx->libctx, cms_ctx->propq) < 0) {
376 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
377 goto err;
378 }
379
380 /* Finally wrap/unwrap the key */
381
382 if (en_de) {
383
384 if (!kek_wrap_key(NULL, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
385 goto err;
386
387 key = OPENSSL_malloc(keylen);
388
389 if (key == NULL)
390 goto err;
391
392 if (!kek_wrap_key(key, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
393 goto err;
394 pwri->encryptedKey->data = key;
395 pwri->encryptedKey->length = keylen;
396 } else {
397 key = OPENSSL_malloc(pwri->encryptedKey->length);
398 if (key == NULL)
399 goto err;
400 if (!kek_unwrap_key(key, &keylen,
401 pwri->encryptedKey->data,
402 pwri->encryptedKey->length, kekctx)) {
403 ERR_raise(ERR_LIB_CMS, CMS_R_UNWRAP_FAILURE);
404 goto err;
405 }
406
407 OPENSSL_clear_free(ec->key, ec->keylen);
408 ec->key = key;
409 ec->keylen = keylen;
410
411 }
412
413 r = 1;
414
415 err:
416 EVP_CIPHER_free(kekcipher);
417 EVP_CIPHER_CTX_free(kekctx);
418
419 if (!r)
420 OPENSSL_free(key);
421 X509_ALGOR_free(kekalg);
422
423 return r;
424
425 }
426