1 /*
2 * Copyright (c) 2015-2023, Arm Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <assert.h>
8
9 #include <common/debug.h>
10 #include <drivers/auth/crypto_mod.h>
11
12 /* Variable exported by the crypto library through REGISTER_CRYPTO_LIB() */
13
14 /*
15 * The crypto module is responsible for verifying digital signatures and hashes.
16 * It relies on a crypto library to perform the cryptographic operations.
17 *
18 * The crypto module itself does not impose any specific format on signatures,
19 * signature algorithm, keys or hashes, but most cryptographic libraries will
20 * take the parameters as the following DER encoded ASN.1 structures:
21 *
22 * AlgorithmIdentifier ::= SEQUENCE {
23 * algorithm OBJECT IDENTIFIER,
24 * parameters ANY DEFINED BY algorithm OPTIONAL
25 * }
26 *
27 * DigestInfo ::= SEQUENCE {
28 * digestAlgorithm AlgorithmIdentifier,
29 * digest OCTET STRING
30 * }
31 *
32 * SubjectPublicKeyInfo ::= SEQUENCE {
33 * algorithm AlgorithmIdentifier,
34 * subjectPublicKey BIT STRING
35 * }
36 *
37 * SignatureAlgorithm ::= AlgorithmIdentifier
38 *
39 * SignatureValue ::= BIT STRING
40 */
41
42 /*
43 * Perform some static checking and call the library initialization function
44 */
crypto_mod_init(void)45 void crypto_mod_init(void)
46 {
47 assert(crypto_lib_desc.name != NULL);
48 assert(crypto_lib_desc.init != NULL);
49 #if CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \
50 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC
51 assert(crypto_lib_desc.verify_signature != NULL);
52 assert(crypto_lib_desc.verify_hash != NULL);
53 #endif /* CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \
54 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */
55
56 #if CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \
57 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC
58 assert(crypto_lib_desc.calc_hash != NULL);
59 #endif /* CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \
60 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */
61
62 /* Initialize the cryptographic library */
63 crypto_lib_desc.init();
64 INFO("Using crypto library '%s'\n", crypto_lib_desc.name);
65 }
66
67 #if CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \
68 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC
69 /*
70 * Function to verify a digital signature
71 *
72 * Parameters:
73 *
74 * data_ptr, data_len: signed data
75 * sig_ptr, sig_len: the digital signature
76 * sig_alg_ptr, sig_alg_len: the digital signature algorithm
77 * pk_ptr, pk_len: the public key
78 */
crypto_mod_verify_signature(void * data_ptr,unsigned int data_len,void * sig_ptr,unsigned int sig_len,void * sig_alg_ptr,unsigned int sig_alg_len,void * pk_ptr,unsigned int pk_len)79 int crypto_mod_verify_signature(void *data_ptr, unsigned int data_len,
80 void *sig_ptr, unsigned int sig_len,
81 void *sig_alg_ptr, unsigned int sig_alg_len,
82 void *pk_ptr, unsigned int pk_len)
83 {
84 assert(data_ptr != NULL);
85 assert(data_len != 0);
86 assert(sig_ptr != NULL);
87 assert(sig_len != 0);
88 assert(sig_alg_ptr != NULL);
89 assert(sig_alg_len != 0);
90 assert(pk_ptr != NULL);
91 assert(pk_len != 0);
92
93 return crypto_lib_desc.verify_signature(data_ptr, data_len,
94 sig_ptr, sig_len,
95 sig_alg_ptr, sig_alg_len,
96 pk_ptr, pk_len);
97 }
98
99 /*
100 * Verify a hash by comparison
101 *
102 * Parameters:
103 *
104 * data_ptr, data_len: data to be hashed
105 * digest_info_ptr, digest_info_len: hash to be compared
106 */
crypto_mod_verify_hash(void * data_ptr,unsigned int data_len,void * digest_info_ptr,unsigned int digest_info_len)107 int crypto_mod_verify_hash(void *data_ptr, unsigned int data_len,
108 void *digest_info_ptr, unsigned int digest_info_len)
109 {
110 assert(data_ptr != NULL);
111 assert(data_len != 0);
112 assert(digest_info_ptr != NULL);
113 assert(digest_info_len != 0);
114
115 return crypto_lib_desc.verify_hash(data_ptr, data_len,
116 digest_info_ptr, digest_info_len);
117 }
118 #endif /* CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \
119 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */
120
121 #if CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \
122 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC
123 /*
124 * Calculate a hash
125 *
126 * Parameters:
127 *
128 * alg: message digest algorithm
129 * data_ptr, data_len: data to be hashed
130 * output: resulting hash
131 */
crypto_mod_calc_hash(enum crypto_md_algo alg,void * data_ptr,unsigned int data_len,unsigned char output[CRYPTO_MD_MAX_SIZE])132 int crypto_mod_calc_hash(enum crypto_md_algo alg, void *data_ptr,
133 unsigned int data_len,
134 unsigned char output[CRYPTO_MD_MAX_SIZE])
135 {
136 assert(data_ptr != NULL);
137 assert(data_len != 0);
138 assert(output != NULL);
139
140 return crypto_lib_desc.calc_hash(alg, data_ptr, data_len, output);
141 }
142 #endif /* CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \
143 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */
144
crypto_mod_convert_pk(void * full_pk_ptr,unsigned int full_pk_len,void ** hashed_pk_ptr,unsigned int * hashed_pk_len)145 int crypto_mod_convert_pk(void *full_pk_ptr, unsigned int full_pk_len,
146 void **hashed_pk_ptr, unsigned int *hashed_pk_len)
147 {
148 if (crypto_lib_desc.convert_pk != NULL) {
149 return crypto_lib_desc.convert_pk(full_pk_ptr, full_pk_len,
150 hashed_pk_ptr, hashed_pk_len);
151 }
152
153 *hashed_pk_ptr = full_pk_ptr;
154 *hashed_pk_len = full_pk_len;
155
156 return 0;
157 }
158
159 /*
160 * Authenticated decryption of data
161 *
162 * Parameters:
163 *
164 * dec_algo: authenticated decryption algorithm
165 * data_ptr, len: data to be decrypted (inout param)
166 * key, key_len, key_flags: symmetric decryption key
167 * iv, iv_len: initialization vector
168 * tag, tag_len: authentication tag
169 */
crypto_mod_auth_decrypt(enum crypto_dec_algo dec_algo,void * data_ptr,size_t len,const void * key,unsigned int key_len,unsigned int key_flags,const void * iv,unsigned int iv_len,const void * tag,unsigned int tag_len)170 int crypto_mod_auth_decrypt(enum crypto_dec_algo dec_algo, void *data_ptr,
171 size_t len, const void *key, unsigned int key_len,
172 unsigned int key_flags, const void *iv,
173 unsigned int iv_len, const void *tag,
174 unsigned int tag_len)
175 {
176 assert(crypto_lib_desc.auth_decrypt != NULL);
177 assert(data_ptr != NULL);
178 assert(len != 0U);
179 assert(key != NULL);
180 assert(key_len != 0U);
181 assert(iv != NULL);
182 assert((iv_len != 0U) && (iv_len <= CRYPTO_MAX_IV_SIZE));
183 assert(tag != NULL);
184 assert((tag_len != 0U) && (tag_len <= CRYPTO_MAX_TAG_SIZE));
185
186 return crypto_lib_desc.auth_decrypt(dec_algo, data_ptr, len, key,
187 key_len, key_flags, iv, iv_len, tag,
188 tag_len);
189 }
190
