2 * Copyright 2013-2016 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/aes.h>
17 #include "cms_local.h"
18 #include "crypto/asn1.h"
20 /* Key Agreement Recipient Info (KARI) routines */
22 int CMS_RecipientInfo_kari_get0_alg(CMS_RecipientInfo *ri,
24 ASN1_OCTET_STRING **pukm)
26 if (ri->type != CMS_RECIPINFO_AGREE) {
27 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ALG,
28 CMS_R_NOT_KEY_AGREEMENT);
32 *palg = ri->d.kari->keyEncryptionAlgorithm;
34 *pukm = ri->d.kari->ukm;
38 /* Retrieve recipient encrypted keys from a kari */
40 STACK_OF(CMS_RecipientEncryptedKey)
41 *CMS_RecipientInfo_kari_get0_reks(CMS_RecipientInfo *ri)
43 if (ri->type != CMS_RECIPINFO_AGREE) {
44 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_REKS,
45 CMS_R_NOT_KEY_AGREEMENT);
48 return ri->d.kari->recipientEncryptedKeys;
51 int CMS_RecipientInfo_kari_get0_orig_id(CMS_RecipientInfo *ri,
53 ASN1_BIT_STRING **pubkey,
54 ASN1_OCTET_STRING **keyid,
58 CMS_OriginatorIdentifierOrKey *oik;
59 if (ri->type != CMS_RECIPINFO_AGREE) {
60 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_GET0_ORIG_ID,
61 CMS_R_NOT_KEY_AGREEMENT);
64 oik = ri->d.kari->originator;
75 if (oik->type == CMS_OIK_ISSUER_SERIAL) {
77 *issuer = oik->d.issuerAndSerialNumber->issuer;
79 *sno = oik->d.issuerAndSerialNumber->serialNumber;
80 } else if (oik->type == CMS_OIK_KEYIDENTIFIER) {
82 *keyid = oik->d.subjectKeyIdentifier;
83 } else if (oik->type == CMS_OIK_PUBKEY) {
85 *pubalg = oik->d.originatorKey->algorithm;
87 *pubkey = oik->d.originatorKey->publicKey;
93 int CMS_RecipientInfo_kari_orig_id_cmp(CMS_RecipientInfo *ri, X509 *cert)
95 CMS_OriginatorIdentifierOrKey *oik;
96 if (ri->type != CMS_RECIPINFO_AGREE) {
97 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ORIG_ID_CMP,
98 CMS_R_NOT_KEY_AGREEMENT);
101 oik = ri->d.kari->originator;
102 if (oik->type == CMS_OIK_ISSUER_SERIAL)
103 return cms_ias_cert_cmp(oik->d.issuerAndSerialNumber, cert);
104 else if (oik->type == CMS_OIK_KEYIDENTIFIER)
105 return cms_keyid_cert_cmp(oik->d.subjectKeyIdentifier, cert);
109 int CMS_RecipientEncryptedKey_get0_id(CMS_RecipientEncryptedKey *rek,
110 ASN1_OCTET_STRING **keyid,
111 ASN1_GENERALIZEDTIME **tm,
112 CMS_OtherKeyAttribute **other,
113 X509_NAME **issuer, ASN1_INTEGER **sno)
115 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
116 if (rid->type == CMS_REK_ISSUER_SERIAL) {
118 *issuer = rid->d.issuerAndSerialNumber->issuer;
120 *sno = rid->d.issuerAndSerialNumber->serialNumber;
127 } else if (rid->type == CMS_REK_KEYIDENTIFIER) {
129 *keyid = rid->d.rKeyId->subjectKeyIdentifier;
131 *tm = rid->d.rKeyId->date;
133 *other = rid->d.rKeyId->other;
143 int CMS_RecipientEncryptedKey_cert_cmp(CMS_RecipientEncryptedKey *rek,
146 CMS_KeyAgreeRecipientIdentifier *rid = rek->rid;
147 if (rid->type == CMS_REK_ISSUER_SERIAL)
148 return cms_ias_cert_cmp(rid->d.issuerAndSerialNumber, cert);
149 else if (rid->type == CMS_REK_KEYIDENTIFIER)
150 return cms_keyid_cert_cmp(rid->d.rKeyId->subjectKeyIdentifier, cert);
155 int CMS_RecipientInfo_kari_set0_pkey_and_peer(CMS_RecipientInfo *ri, EVP_PKEY *pk, X509 *peer)
158 CMS_KeyAgreeRecipientInfo *kari = ri->d.kari;
160 EVP_PKEY_CTX_free(kari->pctx);
165 pctx = EVP_PKEY_CTX_new(pk, NULL);
166 if (pctx == NULL || EVP_PKEY_derive_init(pctx) <= 0)
170 EVP_PKEY *pub_pkey = X509_get0_pubkey(peer);
172 if (EVP_PKEY_derive_set_peer(pctx, pub_pkey) <= 0)
179 EVP_PKEY_CTX_free(pctx);
183 int CMS_RecipientInfo_kari_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pk)
185 return CMS_RecipientInfo_kari_set0_pkey_and_peer(ri, pk, NULL);
188 EVP_CIPHER_CTX *CMS_RecipientInfo_kari_get0_ctx(CMS_RecipientInfo *ri)
190 if (ri->type == CMS_RECIPINFO_AGREE)
191 return ri->d.kari->ctx;
196 * Derive KEK and decrypt/encrypt with it to produce either the original CEK
197 * or the encrypted CEK.
200 static int cms_kek_cipher(unsigned char **pout, size_t *poutlen,
201 const unsigned char *in, size_t inlen,
202 CMS_KeyAgreeRecipientInfo *kari, int enc)
204 /* Key encryption key */
205 unsigned char kek[EVP_MAX_KEY_LENGTH];
208 unsigned char *out = NULL;
210 keklen = EVP_CIPHER_CTX_key_length(kari->ctx);
211 if (keklen > EVP_MAX_KEY_LENGTH)
214 if (EVP_PKEY_derive(kari->pctx, kek, &keklen) <= 0)
216 /* Set KEK in context */
217 if (!EVP_CipherInit_ex(kari->ctx, NULL, NULL, kek, NULL, enc))
219 /* obtain output length of ciphered key */
220 if (!EVP_CipherUpdate(kari->ctx, NULL, &outlen, in, inlen))
222 out = OPENSSL_malloc(outlen);
225 if (!EVP_CipherUpdate(kari->ctx, out, &outlen, in, inlen))
228 *poutlen = (size_t)outlen;
232 OPENSSL_cleanse(kek, keklen);
235 EVP_CIPHER_CTX_reset(kari->ctx);
236 /* FIXME: WHY IS kari->pctx freed here? /RL */
237 EVP_PKEY_CTX_free(kari->pctx);
242 int CMS_RecipientInfo_kari_decrypt(CMS_ContentInfo *cms,
243 CMS_RecipientInfo *ri,
244 CMS_RecipientEncryptedKey *rek)
247 unsigned char *enckey = NULL, *cek = NULL;
250 CMS_EncryptedContentInfo *ec;
251 enckeylen = rek->encryptedKey->length;
252 enckey = rek->encryptedKey->data;
253 /* Setup all parameters to derive KEK */
254 if (!cms_env_asn1_ctrl(ri, 1))
256 /* Attempt to decrypt CEK */
257 if (!cms_kek_cipher(&cek, &ceklen, enckey, enckeylen, ri->d.kari, 0))
259 ec = cms->d.envelopedData->encryptedContentInfo;
260 OPENSSL_clear_free(ec->key, ec->keylen);
270 /* Create ephemeral key and initialise context based on it */
271 static int cms_kari_create_ephemeral_key(CMS_KeyAgreeRecipientInfo *kari,
274 EVP_PKEY_CTX *pctx = NULL;
275 EVP_PKEY *ekey = NULL;
278 pctx = EVP_PKEY_CTX_new(pk, NULL);
281 if (EVP_PKEY_keygen_init(pctx) <= 0)
283 if (EVP_PKEY_keygen(pctx, &ekey) <= 0)
285 EVP_PKEY_CTX_free(pctx);
286 pctx = EVP_PKEY_CTX_new(ekey, NULL);
289 if (EVP_PKEY_derive_init(pctx) <= 0)
295 EVP_PKEY_CTX_free(pctx);
300 /* Set originator private key and initialise context based on it */
301 static int cms_kari_set_originator_private_key(CMS_KeyAgreeRecipientInfo *kari, EVP_PKEY *originatorPrivKey )
303 EVP_PKEY_CTX *pctx = NULL;
306 pctx = EVP_PKEY_CTX_new(originatorPrivKey, NULL);
309 if (EVP_PKEY_derive_init(pctx) <= 0)
316 EVP_PKEY_CTX_free(pctx);
320 /* Initialise a kari based on passed certificate and key */
322 int cms_RecipientInfo_kari_init(CMS_RecipientInfo *ri, X509 *recip, EVP_PKEY *recipPubKey, X509 * originator, EVP_PKEY *originatorPrivKey, unsigned int flags)
324 CMS_KeyAgreeRecipientInfo *kari;
325 CMS_RecipientEncryptedKey *rek = NULL;
327 ri->d.kari = M_ASN1_new_of(CMS_KeyAgreeRecipientInfo);
330 ri->type = CMS_RECIPINFO_AGREE;
335 rek = M_ASN1_new_of(CMS_RecipientEncryptedKey);
339 if (!sk_CMS_RecipientEncryptedKey_push(kari->recipientEncryptedKeys, rek)) {
340 M_ASN1_free_of(rek, CMS_RecipientEncryptedKey);
344 if (flags & CMS_USE_KEYID) {
345 rek->rid->type = CMS_REK_KEYIDENTIFIER;
346 rek->rid->d.rKeyId = M_ASN1_new_of(CMS_RecipientKeyIdentifier);
347 if (rek->rid->d.rKeyId == NULL)
349 if (!cms_set1_keyid(&rek->rid->d.rKeyId->subjectKeyIdentifier, recip))
352 rek->rid->type = CMS_REK_ISSUER_SERIAL;
353 if (!cms_set1_ias(&rek->rid->d.issuerAndSerialNumber, recip))
357 if (originatorPrivKey == NULL && originator == NULL) {
358 /* Create ephemeral key */
359 if (!cms_kari_create_ephemeral_key(kari, recipPubKey))
362 /* Use originator key */
363 CMS_OriginatorIdentifierOrKey *oik = ri->d.kari->originator;
365 if (originatorPrivKey == NULL && originator == NULL)
368 if (flags & CMS_USE_ORIGINATOR_KEYID) {
369 oik->type = CMS_OIK_KEYIDENTIFIER;
370 oik->d.subjectKeyIdentifier = ASN1_OCTET_STRING_new();
371 if (oik->d.subjectKeyIdentifier == NULL)
373 if (!cms_set1_keyid(&oik->d.subjectKeyIdentifier, originator))
376 oik->type = CMS_REK_ISSUER_SERIAL;
377 if (!cms_set1_ias(&oik->d.issuerAndSerialNumber, originator))
381 if (!cms_kari_set_originator_private_key(kari, originatorPrivKey))
385 EVP_PKEY_up_ref(recipPubKey);
386 rek->pkey = recipPubKey;
390 static int cms_wrap_init(CMS_KeyAgreeRecipientInfo *kari,
391 const EVP_CIPHER *cipher)
393 EVP_CIPHER_CTX *ctx = kari->ctx;
394 const EVP_CIPHER *kekcipher;
395 int keylen = EVP_CIPHER_key_length(cipher);
398 /* If a suitable wrap algorithm is already set nothing to do */
399 kekcipher = EVP_CIPHER_CTX_cipher(ctx);
400 if (kekcipher != NULL) {
401 if (EVP_CIPHER_CTX_mode(ctx) != EVP_CIPH_WRAP_MODE)
405 else if (cipher != NULL
406 && (EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_GET_WRAP_CIPHER)) {
407 ret = EVP_CIPHER_meth_get_ctrl(cipher)(NULL, EVP_CTRL_GET_WRAP_CIPHER,
412 if (kekcipher != NULL) {
413 if (EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
416 return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
421 * Pick a cipher based on content encryption cipher. If it is DES3 use
422 * DES3 wrap otherwise use AES wrap similar to key size.
424 #ifndef OPENSSL_NO_DES
425 if (EVP_CIPHER_type(cipher) == NID_des_ede3_cbc)
426 kekcipher = EVP_des_ede3_wrap();
430 kekcipher = EVP_aes_128_wrap();
431 else if (keylen <= 24)
432 kekcipher = EVP_aes_192_wrap();
434 kekcipher = EVP_aes_256_wrap();
435 return EVP_EncryptInit_ex(ctx, kekcipher, NULL, NULL, NULL);
438 /* Encrypt content key in key agreement recipient info */
440 int cms_RecipientInfo_kari_encrypt(const CMS_ContentInfo *cms,
441 CMS_RecipientInfo *ri)
443 CMS_KeyAgreeRecipientInfo *kari;
444 CMS_EncryptedContentInfo *ec;
445 CMS_RecipientEncryptedKey *rek;
446 STACK_OF(CMS_RecipientEncryptedKey) *reks;
449 if (ri->type != CMS_RECIPINFO_AGREE) {
450 CMSerr(CMS_F_CMS_RECIPIENTINFO_KARI_ENCRYPT, CMS_R_NOT_KEY_AGREEMENT);
454 reks = kari->recipientEncryptedKeys;
455 ec = cms->d.envelopedData->encryptedContentInfo;
456 /* Initialise wrap algorithm parameters */
457 if (!cms_wrap_init(kari, ec->cipher))
460 * If no originator key set up initialise for ephemeral key the public key
461 * ASN1 structure will set the actual public key value.
463 if (kari->originator->type == -1) {
464 CMS_OriginatorIdentifierOrKey *oik = kari->originator;
465 oik->type = CMS_OIK_PUBKEY;
466 oik->d.originatorKey = M_ASN1_new_of(CMS_OriginatorPublicKey);
467 if (!oik->d.originatorKey)
470 /* Initialise KDF algorithm */
471 if (!cms_env_asn1_ctrl(ri, 0))
473 /* For each rek, derive KEK, encrypt CEK */
474 for (i = 0; i < sk_CMS_RecipientEncryptedKey_num(reks); i++) {
475 unsigned char *enckey;
477 rek = sk_CMS_RecipientEncryptedKey_value(reks, i);
478 if (EVP_PKEY_derive_set_peer(kari->pctx, rek->pkey) <= 0)
480 if (!cms_kek_cipher(&enckey, &enckeylen, ec->key, ec->keylen,
483 ASN1_STRING_set0(rek->encryptedKey, enckey, enckeylen);