1/* 2 * QEMU Crypto akcipher algorithms 3 * 4 * Copyright (c) 2022 Bytedance 5 * Author: lei he <helei.sig11@bytedance.com> 6 * 7 * This library is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * This library is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 19 * 20 */ 21 22#include "der.h" 23#include "rsakey.h" 24 25static int extract_mpi(void *ctx, const uint8_t *value, 26 size_t vlen, Error **errp) 27{ 28 QCryptoAkCipherMPI *mpi = (QCryptoAkCipherMPI *)ctx; 29 if (vlen == 0) { 30 error_setg(errp, "Empty mpi field"); 31 return -1; 32 } 33 mpi->data = g_memdup2(value, vlen); 34 mpi->len = vlen; 35 return 0; 36} 37 38static int extract_version(void *ctx, const uint8_t *value, 39 size_t vlen, Error **errp) 40{ 41 uint8_t *version = (uint8_t *)ctx; 42 if (vlen != 1 || *value > 1) { 43 error_setg(errp, "Invalid rsakey version"); 44 return -1; 45 } 46 *version = *value; 47 return 0; 48} 49 50static int extract_seq_content(void *ctx, const uint8_t *value, 51 size_t vlen, Error **errp) 52{ 53 const uint8_t **content = (const uint8_t **)ctx; 54 if (vlen == 0) { 55 error_setg(errp, "Empty sequence"); 56 return -1; 57 } 58 *content = value; 59 return 0; 60} 61 62/** 63 * 64 * RsaPubKey ::= SEQUENCE { 65 * n INTEGER 66 * e INTEGER 67 * } 68 */ 69static QCryptoAkCipherRSAKey *qcrypto_builtin_rsa_public_key_parse( 70 const uint8_t *key, size_t keylen, Error **errp) 71{ 72 QCryptoAkCipherRSAKey *rsa = g_new0(QCryptoAkCipherRSAKey, 1); 73 const uint8_t *seq; 74 size_t seq_length; 75 int decode_ret; 76 77 decode_ret = qcrypto_der_decode_seq(&key, &keylen, 78 extract_seq_content, &seq, errp); 79 if (decode_ret < 0 || keylen != 0) { 80 goto error; 81 } 82 seq_length = decode_ret; 83 84 if (qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, 85 &rsa->n, errp) < 0 || 86 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, 87 &rsa->e, errp) < 0) { 88 goto error; 89 } 90 if (seq_length != 0) { 91 error_setg(errp, "Invalid RSA public key"); 92 goto error; 93 } 94 95 return rsa; 96 97error: 98 qcrypto_akcipher_rsakey_free(rsa); 99 return NULL; 100} 101 102/** 103 * RsaPrivKey ::= SEQUENCE { 104 * version INTEGER 105 * n INTEGER 106 * e INTEGER 107 * d INTEGER 108 * p INTEGER 109 * q INTEGER 110 * dp INTEGER 111 * dq INTEGER 112 * u INTEGER 113 * otherPrimeInfos OtherPrimeInfos OPTIONAL 114 * } 115 */ 116static QCryptoAkCipherRSAKey *qcrypto_builtin_rsa_private_key_parse( 117 const uint8_t *key, size_t keylen, Error **errp) 118{ 119 QCryptoAkCipherRSAKey *rsa = g_new0(QCryptoAkCipherRSAKey, 1); 120 uint8_t version; 121 const uint8_t *seq; 122 int decode_ret; 123 size_t seq_length; 124 125 decode_ret = qcrypto_der_decode_seq(&key, &keylen, extract_seq_content, 126 &seq, errp); 127 if (decode_ret < 0 || keylen != 0) { 128 goto error; 129 } 130 seq_length = decode_ret; 131 132 decode_ret = qcrypto_der_decode_int(&seq, &seq_length, extract_version, 133 &version, errp); 134 135 if (qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, 136 &rsa->n, errp) < 0 || 137 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, 138 &rsa->e, errp) < 0 || 139 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, 140 &rsa->d, errp) < 0 || 141 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, &rsa->p, 142 errp) < 0 || 143 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, &rsa->q, 144 errp) < 0 || 145 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, &rsa->dp, 146 errp) < 0 || 147 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, &rsa->dq, 148 errp) < 0 || 149 qcrypto_der_decode_int(&seq, &seq_length, extract_mpi, &rsa->u, 150 errp) < 0) { 151 goto error; 152 } 153 154 /** 155 * According to the standard, otherPrimeInfos must be present for version 1. 156 * There is no strict verification here, this is to be compatible with 157 * the unit test of the kernel. TODO: remove this until linux kernel's 158 * unit-test is fixed. 159 */ 160 if (version == 1 && seq_length != 0) { 161 if (qcrypto_der_decode_seq(&seq, &seq_length, NULL, NULL, errp) < 0) { 162 goto error; 163 } 164 if (seq_length != 0) { 165 goto error; 166 } 167 return rsa; 168 } 169 if (seq_length != 0) { 170 error_setg(errp, "Invalid RSA private key"); 171 goto error; 172 } 173 174 return rsa; 175 176error: 177 qcrypto_akcipher_rsakey_free(rsa); 178 return NULL; 179} 180 181QCryptoAkCipherRSAKey *qcrypto_akcipher_rsakey_parse( 182 QCryptoAkCipherKeyType type, const uint8_t *key, 183 size_t keylen, Error **errp) 184{ 185 switch (type) { 186 case QCRYPTO_AK_CIPHER_KEY_TYPE_PRIVATE: 187 return qcrypto_builtin_rsa_private_key_parse(key, keylen, errp); 188 189 case QCRYPTO_AK_CIPHER_KEY_TYPE_PUBLIC: 190 return qcrypto_builtin_rsa_public_key_parse(key, keylen, errp); 191 192 default: 193 error_setg(errp, "Unknown key type: %d", type); 194 return NULL; 195 } 196} 197