2 * Copyright 2009-2024 The OpenSSL Project Authors. All Rights Reserved.
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
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"
22 int CMS_RecipientInfo_set0_password(CMS_RecipientInfo *ri,
23 unsigned char *pass, ossl_ssize_t passlen)
25 CMS_PasswordRecipientInfo *pwri;
26 if (ri->type != CMS_RECIPINFO_PASS) {
27 ERR_raise(ERR_LIB_CMS, CMS_R_NOT_PWRI);
33 if (pass && passlen < 0)
34 passlen = strlen((char *)pass);
35 pwri->passlen = passlen;
39 CMS_RecipientInfo *CMS_add0_recipient_password(CMS_ContentInfo *cms,
40 int iter, int wrap_nid,
44 const EVP_CIPHER *kekciph)
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];
54 const CMS_CTX *cms_ctx = ossl_cms_get0_cmsctx(cms);
56 ec = ossl_cms_get0_env_enc_content(cms);
59 ris = CMS_get0_RecipientInfos(cms);
64 wrap_nid = NID_id_alg_PWRI_KEK;
67 pbe_nid = NID_id_pbkdf2;
69 /* Get from enveloped data */
73 if (kekciph == NULL) {
74 ERR_raise(ERR_LIB_CMS, CMS_R_NO_CIPHER);
77 if (wrap_nid != NID_id_alg_PWRI_KEK) {
78 ERR_raise(ERR_LIB_CMS, CMS_R_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM);
82 /* Setup algorithm identifier for cipher */
83 encalg = X509_ALGOR_new();
85 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
88 ctx = EVP_CIPHER_CTX_new();
90 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
94 if (EVP_EncryptInit_ex(ctx, kekciph, NULL, NULL, NULL) <= 0) {
95 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
99 ivlen = EVP_CIPHER_CTX_get_iv_length(ctx);
101 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
106 if (RAND_bytes_ex(ossl_cms_ctx_get0_libctx(cms_ctx), iv, ivlen, 0) <= 0)
108 if (EVP_EncryptInit_ex(ctx, NULL, NULL, NULL, iv) <= 0) {
109 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
112 encalg->parameter = ASN1_TYPE_new();
113 if (!encalg->parameter) {
114 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
117 if (EVP_CIPHER_param_to_asn1(ctx, encalg->parameter) <= 0) {
118 ERR_raise(ERR_LIB_CMS, CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
123 encalg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_get_type(ctx));
125 EVP_CIPHER_CTX_free(ctx);
128 /* Initialize recipient info */
129 ri = M_ASN1_new_of(CMS_RecipientInfo);
131 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
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);
140 ri->type = CMS_RECIPINFO_PASS;
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);
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);
158 if (!ASN1_item_pack(encalg, ASN1_ITEM_rptr(X509_ALGOR),
159 &pwri->keyEncryptionAlgorithm->parameter->
161 ERR_raise(ERR_LIB_CMS, ERR_R_ASN1_LIB);
164 pwri->keyEncryptionAlgorithm->parameter->type = V_ASN1_SEQUENCE;
166 X509_ALGOR_free(encalg);
169 /* Setup PBE algorithm */
171 pwri->keyDerivationAlgorithm = PKCS5_pbkdf2_set(iter, NULL, 0, -1, -1);
173 if (pwri->keyDerivationAlgorithm == NULL)
176 CMS_RecipientInfo_set0_password(ri, pass, passlen);
179 if (!sk_CMS_RecipientInfo_push(ris, ri)) {
180 ERR_raise(ERR_LIB_CMS, ERR_R_CRYPTO_LIB);
187 EVP_CIPHER_CTX_free(ctx);
189 M_ASN1_free_of(ri, CMS_RecipientInfo);
190 X509_ALGOR_free(encalg);
196 * This is an implementation of the key wrapping mechanism in RFC3211, at
197 * some point this should go into EVP.
200 static int kek_unwrap_key(unsigned char *out, size_t *outlen,
201 const unsigned char *in, size_t inlen,
204 size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
211 if (inlen < 2 * blocklen) {
215 if (inlen % blocklen) {
219 if ((tmp = OPENSSL_malloc(inlen)) == NULL)
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)
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.
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)
234 /* Reset IV to original value */
235 || !EVP_DecryptInit_ex(ctx, NULL, NULL, NULL, NULL)
237 || !EVP_DecryptUpdate(ctx, tmp, &outl, tmp, inlen))
239 /* Check check bytes */
240 if (((tmp[1] ^ tmp[4]) & (tmp[2] ^ tmp[5]) & (tmp[3] ^ tmp[6])) != 0xff) {
241 /* Check byte failure */
244 if (inlen < (size_t)(tmp[0] - 4)) {
245 /* Invalid length value */
248 *outlen = (size_t)tmp[0];
249 memcpy(out, tmp + 4, *outlen);
252 OPENSSL_clear_free(tmp, inlen);
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)
261 size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
269 * First decide length of output buffer: need header and round up to
270 * multiple of block length.
272 olen = (inlen + 4 + blocklen - 1) / blocklen;
274 if (olen < 2 * blocklen) {
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 */
291 && RAND_bytes_ex(ossl_cms_ctx_get0_libctx(cms_ctx), out + 4 + inlen,
292 olen - 4 - inlen, 0) <= 0)
295 if (!EVP_EncryptUpdate(ctx, out, &dummy, out, olen)
296 || !EVP_EncryptUpdate(ctx, out, &dummy, out, olen))
305 /* Encrypt/Decrypt content key in PWRI recipient info */
307 int ossl_cms_RecipientInfo_pwri_crypt(const CMS_ContentInfo *cms,
308 CMS_RecipientInfo *ri, int en_de)
310 CMS_EncryptedContentInfo *ec;
311 CMS_PasswordRecipientInfo *pwri;
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;
319 const CMS_CTX *cms_ctx = ossl_cms_get0_cmsctx(cms);
321 ec = ossl_cms_get0_env_enc_content(cms);
325 if (pwri->pass == NULL) {
326 ERR_raise(ERR_LIB_CMS, CMS_R_NO_PASSWORD);
329 algtmp = pwri->keyEncryptionAlgorithm;
331 if (!algtmp || OBJ_obj2nid(algtmp->algorithm) != NID_id_alg_PWRI_KEK) {
332 ERR_raise(ERR_LIB_CMS, CMS_R_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM);
336 kekalg = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(X509_ALGOR),
339 if (kekalg == NULL) {
340 ERR_raise(ERR_LIB_CMS, CMS_R_INVALID_KEY_ENCRYPTION_PARAMETER);
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));
348 if (kekcipher == NULL) {
349 ERR_raise(ERR_LIB_CMS, CMS_R_UNKNOWN_CIPHER);
353 kekctx = EVP_CIPHER_CTX_new();
354 if (kekctx == NULL) {
355 ERR_raise(ERR_LIB_CMS, ERR_R_EVP_LIB);
358 /* Fixup cipher based on AlgorithmIdentifier to set IV etc */
359 if (!EVP_CipherInit_ex(kekctx, kekcipher, NULL, NULL, NULL, en_de))
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);
367 algtmp = pwri->keyDerivationAlgorithm;
369 /* Finish password based key derivation to setup key in "ctx" */
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);
378 /* Finally wrap/unwrap the key */
382 if (!kek_wrap_key(NULL, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
385 key = OPENSSL_malloc(keylen);
390 if (!kek_wrap_key(key, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
392 pwri->encryptedKey->data = key;
393 pwri->encryptedKey->length = keylen;
395 key = OPENSSL_malloc(pwri->encryptedKey->length);
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);
405 OPENSSL_clear_free(ec->key, ec->keylen);
414 EVP_CIPHER_free(kekcipher);
415 EVP_CIPHER_CTX_free(kekctx);
419 X509_ALGOR_free(kekalg);