1 | /* |
2 | * Copyright 2008-2018 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 "cms_local.h" |
18 | |
19 | /* CMS EncryptedData Utilities */ |
20 | |
21 | /* Return BIO based on EncryptedContentInfo and key */ |
22 | |
23 | BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec) |
24 | { |
25 | BIO *b; |
26 | EVP_CIPHER_CTX *ctx; |
27 | const EVP_CIPHER *ciph; |
28 | X509_ALGOR *calg = ec->contentEncryptionAlgorithm; |
29 | unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL; |
30 | unsigned char *tkey = NULL; |
31 | size_t tkeylen = 0; |
32 | |
33 | int ok = 0; |
34 | |
35 | int enc, keep_key = 0; |
36 | |
37 | enc = ec->cipher ? 1 : 0; |
38 | |
39 | b = BIO_new(BIO_f_cipher()); |
40 | if (b == NULL) { |
41 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE); |
42 | return NULL; |
43 | } |
44 | |
45 | BIO_get_cipher_ctx(b, &ctx); |
46 | |
47 | if (enc) { |
48 | ciph = ec->cipher; |
49 | /* |
50 | * If not keeping key set cipher to NULL so subsequent calls decrypt. |
51 | */ |
52 | if (ec->key) |
53 | ec->cipher = NULL; |
54 | } else { |
55 | ciph = EVP_get_cipherbyobj(calg->algorithm); |
56 | |
57 | if (!ciph) { |
58 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, CMS_R_UNKNOWN_CIPHER); |
59 | goto err; |
60 | } |
61 | } |
62 | |
63 | if (EVP_CipherInit_ex(ctx, ciph, NULL, NULL, NULL, enc) <= 0) { |
64 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, |
65 | CMS_R_CIPHER_INITIALISATION_ERROR); |
66 | goto err; |
67 | } |
68 | |
69 | if (enc) { |
70 | int ivlen; |
71 | calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_type(ctx)); |
72 | /* Generate a random IV if we need one */ |
73 | ivlen = EVP_CIPHER_CTX_iv_length(ctx); |
74 | if (ivlen > 0) { |
75 | if (RAND_bytes(iv, ivlen) <= 0) |
76 | goto err; |
77 | piv = iv; |
78 | } |
79 | } else if (EVP_CIPHER_asn1_to_param(ctx, calg->parameter) <= 0) { |
80 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, |
81 | CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR); |
82 | goto err; |
83 | } |
84 | tkeylen = EVP_CIPHER_CTX_key_length(ctx); |
85 | /* Generate random session key */ |
86 | if (!enc || !ec->key) { |
87 | tkey = OPENSSL_malloc(tkeylen); |
88 | if (tkey == NULL) { |
89 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE); |
90 | goto err; |
91 | } |
92 | if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0) |
93 | goto err; |
94 | } |
95 | |
96 | if (!ec->key) { |
97 | ec->key = tkey; |
98 | ec->keylen = tkeylen; |
99 | tkey = NULL; |
100 | if (enc) |
101 | keep_key = 1; |
102 | else |
103 | ERR_clear_error(); |
104 | |
105 | } |
106 | |
107 | if (ec->keylen != tkeylen) { |
108 | /* If necessary set key length */ |
109 | if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) { |
110 | /* |
111 | * Only reveal failure if debugging so we don't leak information |
112 | * which may be useful in MMA. |
113 | */ |
114 | if (enc || ec->debug) { |
115 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, |
116 | CMS_R_INVALID_KEY_LENGTH); |
117 | goto err; |
118 | } else { |
119 | /* Use random key */ |
120 | OPENSSL_clear_free(ec->key, ec->keylen); |
121 | ec->key = tkey; |
122 | ec->keylen = tkeylen; |
123 | tkey = NULL; |
124 | ERR_clear_error(); |
125 | } |
126 | } |
127 | } |
128 | |
129 | if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) { |
130 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, |
131 | CMS_R_CIPHER_INITIALISATION_ERROR); |
132 | goto err; |
133 | } |
134 | if (enc) { |
135 | calg->parameter = ASN1_TYPE_new(); |
136 | if (calg->parameter == NULL) { |
137 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE); |
138 | goto err; |
139 | } |
140 | if (EVP_CIPHER_param_to_asn1(ctx, calg->parameter) <= 0) { |
141 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, |
142 | CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR); |
143 | goto err; |
144 | } |
145 | /* If parameter type not set omit parameter */ |
146 | if (calg->parameter->type == V_ASN1_UNDEF) { |
147 | ASN1_TYPE_free(calg->parameter); |
148 | calg->parameter = NULL; |
149 | } |
150 | } |
151 | ok = 1; |
152 | |
153 | err: |
154 | if (!keep_key || !ok) { |
155 | OPENSSL_clear_free(ec->key, ec->keylen); |
156 | ec->key = NULL; |
157 | } |
158 | OPENSSL_clear_free(tkey, tkeylen); |
159 | if (ok) |
160 | return b; |
161 | BIO_free(b); |
162 | return NULL; |
163 | } |
164 | |
165 | int cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec, |
166 | const EVP_CIPHER *cipher, |
167 | const unsigned char *key, size_t keylen) |
168 | { |
169 | ec->cipher = cipher; |
170 | if (key) { |
171 | if ((ec->key = OPENSSL_malloc(keylen)) == NULL) { |
172 | CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT, ERR_R_MALLOC_FAILURE); |
173 | return 0; |
174 | } |
175 | memcpy(ec->key, key, keylen); |
176 | } |
177 | ec->keylen = keylen; |
178 | if (cipher) |
179 | ec->contentType = OBJ_nid2obj(NID_pkcs7_data); |
180 | return 1; |
181 | } |
182 | |
183 | int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph, |
184 | const unsigned char *key, size_t keylen) |
185 | { |
186 | CMS_EncryptedContentInfo *ec; |
187 | if (!key || !keylen) { |
188 | CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NO_KEY); |
189 | return 0; |
190 | } |
191 | if (ciph) { |
192 | cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData); |
193 | if (!cms->d.encryptedData) { |
194 | CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, ERR_R_MALLOC_FAILURE); |
195 | return 0; |
196 | } |
197 | cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted); |
198 | cms->d.encryptedData->version = 0; |
199 | } else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) { |
200 | CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NOT_ENCRYPTED_DATA); |
201 | return 0; |
202 | } |
203 | ec = cms->d.encryptedData->encryptedContentInfo; |
204 | return cms_EncryptedContent_init(ec, ciph, key, keylen); |
205 | } |
206 | |
207 | BIO *cms_EncryptedData_init_bio(const CMS_ContentInfo *cms) |
208 | { |
209 | CMS_EncryptedData *enc = cms->d.encryptedData; |
210 | if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs) |
211 | enc->version = 2; |
212 | return cms_EncryptedContent_init_bio(enc->encryptedContentInfo); |
213 | } |
214 | |