1 /* 2 * Copyright (c) 2015-2025, Arm Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <stdint.h> 9 10 #include <common/debug.h> 11 #include <drivers/auth/crypto_mod.h> 12 #include <drivers/measured_boot/event_log/tcg.h> 13 14 /* Variable exported by the crypto library through REGISTER_CRYPTO_LIB() */ 15 16 /* 17 * The crypto module is responsible for verifying digital signatures and hashes. 18 * It relies on a crypto library to perform the cryptographic operations. 19 * 20 * The crypto module itself does not impose any specific format on signatures, 21 * signature algorithm, keys or hashes, but most cryptographic libraries will 22 * take the parameters as the following DER encoded ASN.1 structures: 23 * 24 * AlgorithmIdentifier ::= SEQUENCE { 25 * algorithm OBJECT IDENTIFIER, 26 * parameters ANY DEFINED BY algorithm OPTIONAL 27 * } 28 * 29 * DigestInfo ::= SEQUENCE { 30 * digestAlgorithm AlgorithmIdentifier, 31 * digest OCTET STRING 32 * } 33 * 34 * SubjectPublicKeyInfo ::= SEQUENCE { 35 * algorithm AlgorithmIdentifier, 36 * subjectPublicKey BIT STRING 37 * } 38 * 39 * SignatureAlgorithm ::= AlgorithmIdentifier 40 * 41 * SignatureValue ::= BIT STRING 42 */ 43 44 /* 45 * Perform some static checking and call the library initialization function 46 */ 47 void crypto_mod_init(void) 48 { 49 assert(crypto_lib_desc.name != NULL); 50 assert(crypto_lib_desc.init != NULL); 51 #if CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \ 52 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC 53 assert(crypto_lib_desc.verify_signature != NULL); 54 assert(crypto_lib_desc.verify_hash != NULL); 55 #endif /* CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \ 56 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */ 57 58 #if CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \ 59 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC 60 assert(crypto_lib_desc.calc_hash != NULL); 61 #endif /* CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \ 62 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */ 63 64 /* Initialize the cryptographic library */ 65 crypto_lib_desc.init(); 66 INFO("Using crypto library '%s'\n", crypto_lib_desc.name); 67 } 68 69 #if CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \ 70 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC 71 /* 72 * Function to verify a digital signature 73 * 74 * Parameters: 75 * 76 * data_ptr, data_len: signed data 77 * sig_ptr, sig_len: the digital signature 78 * sig_alg_ptr, sig_alg_len: the digital signature algorithm 79 * pk_ptr, pk_len: the public key 80 */ 81 int crypto_mod_verify_signature(void *data_ptr, unsigned int data_len, 82 void *sig_ptr, unsigned int sig_len, 83 void *sig_alg_ptr, unsigned int sig_alg_len, 84 void *pk_ptr, unsigned int pk_len) 85 { 86 assert(data_ptr != NULL); 87 assert(data_len != 0); 88 assert(sig_ptr != NULL); 89 assert(sig_len != 0); 90 assert(sig_alg_ptr != NULL); 91 assert(sig_alg_len != 0); 92 assert(pk_ptr != NULL); 93 assert(pk_len != 0); 94 95 return crypto_lib_desc.verify_signature(data_ptr, data_len, 96 sig_ptr, sig_len, 97 sig_alg_ptr, sig_alg_len, 98 pk_ptr, pk_len); 99 } 100 101 /* 102 * Verify a hash by comparison 103 * 104 * Parameters: 105 * 106 * data_ptr, data_len: data to be hashed 107 * digest_info_ptr, digest_info_len: hash to be compared 108 */ 109 int crypto_mod_verify_hash(void *data_ptr, unsigned int data_len, 110 void *digest_info_ptr, unsigned int digest_info_len) 111 { 112 assert(data_ptr != NULL); 113 assert(data_len != 0); 114 assert(digest_info_ptr != NULL); 115 assert(digest_info_len != 0); 116 117 return crypto_lib_desc.verify_hash(data_ptr, data_len, 118 digest_info_ptr, digest_info_len); 119 } 120 #endif /* CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_ONLY || \ 121 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */ 122 123 #if CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \ 124 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC 125 /* 126 * Calculate a hash 127 * 128 * Parameters: 129 * 130 * alg: message digest algorithm 131 * data_ptr, data_len: data to be hashed 132 * output: resulting hash 133 */ 134 int crypto_mod_calc_hash(enum crypto_md_algo alg, void *data_ptr, 135 unsigned int data_len, 136 unsigned char output[CRYPTO_MD_MAX_SIZE]) 137 { 138 assert(data_ptr != NULL); 139 assert(data_len != 0); 140 assert(output != NULL); 141 142 return crypto_lib_desc.calc_hash(alg, data_ptr, data_len, output); 143 } 144 145 int crypto_mod_tcg_hash(uint32_t alg_id, void *data_ptr, unsigned int data_len, 146 uint8_t *digest) 147 { 148 enum crypto_md_algo crypto_alg_id; 149 150 assert(data_ptr != NULL); 151 assert(data_len != 0U); 152 assert(digest != NULL); 153 154 switch (alg_id) { 155 case TPM_ALG_SHA256: 156 crypto_alg_id = CRYPTO_MD_SHA256; 157 break; 158 case TPM_ALG_SHA384: 159 crypto_alg_id = CRYPTO_MD_SHA384; 160 break; 161 case TPM_ALG_SHA512: 162 crypto_alg_id = CRYPTO_MD_SHA512; 163 break; 164 default: 165 ERROR("Unsupported TCG algorithm ID %u.\n", alg_id); 166 return -1; 167 } 168 169 return crypto_mod_calc_hash(crypto_alg_id, data_ptr, data_len, digest); 170 } 171 #endif /* CRYPTO_SUPPORT == CRYPTO_HASH_CALC_ONLY || \ 172 CRYPTO_SUPPORT == CRYPTO_AUTH_VERIFY_AND_HASH_CALC */ 173 174 int crypto_mod_convert_pk(void *full_pk_ptr, unsigned int full_pk_len, 175 void **hashed_pk_ptr, unsigned int *hashed_pk_len) 176 { 177 if (crypto_lib_desc.convert_pk != NULL) { 178 return crypto_lib_desc.convert_pk(full_pk_ptr, full_pk_len, 179 hashed_pk_ptr, hashed_pk_len); 180 } 181 182 *hashed_pk_ptr = full_pk_ptr; 183 *hashed_pk_len = full_pk_len; 184 185 return 0; 186 } 187 188 /* 189 * Authenticated decryption of data 190 * 191 * Parameters: 192 * 193 * dec_algo: authenticated decryption algorithm 194 * data_ptr, len: data to be decrypted (inout param) 195 * key, key_len, key_flags: symmetric decryption key 196 * iv, iv_len: initialization vector 197 * tag, tag_len: authentication tag 198 */ 199 int crypto_mod_auth_decrypt(enum crypto_dec_algo dec_algo, void *data_ptr, 200 size_t len, const void *key, unsigned int key_len, 201 unsigned int key_flags, const void *iv, 202 unsigned int iv_len, const void *tag, 203 unsigned int tag_len) 204 { 205 assert(crypto_lib_desc.auth_decrypt != NULL); 206 assert(data_ptr != NULL); 207 assert(len != 0U); 208 assert(key != NULL); 209 assert(key_len != 0U); 210 assert(iv != NULL); 211 assert((iv_len != 0U) && (iv_len <= CRYPTO_MAX_IV_SIZE)); 212 assert(tag != NULL); 213 assert((tag_len != 0U) && (tag_len <= CRYPTO_MAX_TAG_SIZE)); 214 215 return crypto_lib_desc.auth_decrypt(dec_algo, data_ptr, len, key, 216 key_len, key_flags, iv, iv_len, tag, 217 tag_len); 218 } 219 220 /* Perform end of psa crypto usage calls to finish */ 221 void crypto_mod_finish(void) 222 { 223 if (crypto_lib_desc.finish != NULL) { 224 crypto_lib_desc.finish(); 225 INFO("Finished using crypto library '%s'\n", crypto_lib_desc.name); 226 } 227 } 228