| 1 | /* |
| 2 | * libopenemv - a library to work with EMV family of smart cards |
| 3 | * Copyright (C) 2015 Dmitry Eremin-Solenikov |
| 4 | * |
| 5 | * This library is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU Lesser General Public |
| 7 | * License as published by the Free Software Foundation; either |
| 8 | * version 2.1 of the License, or (at your option) any later version. |
| 9 | * |
| 10 | * This library is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * Lesser General Public License for more details. |
| 14 | */ |
| 15 | |
| 16 | #ifdef HAVE_CONFIG_H |
| 17 | #include <config.h> |
| 18 | #endif |
| 19 | |
| 20 | #include "emv_pki_priv.h" |
| 21 | #include "crypto.h" |
| 22 | |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <stdarg.h> |
| 26 | |
| 27 | struct emv_pk *emv_pki_make_ca(const struct crypto_pk *cp, |
| 28 | const unsigned char *rid, unsigned char index, |
| 29 | unsigned int expire, enum crypto_algo_hash hash_algo) |
| 30 | { |
| 31 | size_t modlen, explen; |
| 32 | unsigned char *mod, *exp; |
| 33 | |
| 34 | if (!rid) |
| 35 | return NULL; |
| 36 | |
| 37 | mod = crypto_pk_get_parameter(cp, 0, &modlen); |
| 38 | exp = crypto_pk_get_parameter(cp, 1, &explen); |
| 39 | |
| 40 | if (!mod || !modlen || !exp || !explen) { |
| 41 | free(mod); |
| 42 | free(exp); |
| 43 | |
| 44 | return NULL; |
| 45 | } |
| 46 | |
| 47 | struct emv_pk *pk = emv_pk_new(modlen, explen); |
| 48 | memcpy(pk->rid, rid, 5); |
| 49 | pk->index = index; |
| 50 | pk->expire = expire; |
| 51 | pk->pk_algo = crypto_pk_get_algo(cp); |
| 52 | pk->hash_algo = hash_algo; |
| 53 | memcpy(pk->modulus, mod, modlen); |
| 54 | memcpy(pk->exp, exp, explen); |
| 55 | |
| 56 | free(mod); |
| 57 | free(exp); |
| 58 | |
| 59 | struct crypto_hash *ch = crypto_hash_open(pk->hash_algo); |
| 60 | if (!ch) { |
| 61 | emv_pk_free(pk); |
| 62 | return false; |
| 63 | } |
| 64 | |
| 65 | crypto_hash_write(ch, pk->rid, sizeof(pk->rid)); |
| 66 | crypto_hash_write(ch, &pk->index, 1); |
| 67 | crypto_hash_write(ch, pk->modulus, pk->mlen); |
| 68 | crypto_hash_write(ch, pk->exp, pk->elen); |
| 69 | |
| 70 | unsigned char *h = crypto_hash_read(ch); |
| 71 | if (!h) { |
| 72 | crypto_hash_close(ch); |
| 73 | emv_pk_free(pk); |
| 74 | |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | memcpy(pk->hash, h, crypto_hash_get_size(ch)); |
| 79 | crypto_hash_close(ch); |
| 80 | |
| 81 | return pk; |
| 82 | } |
| 83 | |
| 84 | static struct tlvdb *emv_pki_sign_message(const struct crypto_pk *cp, |
| 85 | tlv_tag_t cert_tag, tlv_tag_t rem_tag, |
| 86 | const unsigned char *msg, size_t msg_len, |
| 87 | ... /* A list of tlv pointers, end with NULL */ |
| 88 | ) |
| 89 | { |
| 90 | size_t tmp_len = (crypto_pk_get_nbits(cp) + 7) / 8; |
| 91 | unsigned char *tmp = malloc(tmp_len); |
| 92 | if (!tmp) |
| 93 | return NULL; |
| 94 | |
| 95 | // XXX |
| 96 | struct crypto_hash *ch = crypto_hash_open(HASH_SHA_1); |
| 97 | if (!ch) { |
| 98 | free(tmp); |
| 99 | |
| 100 | return NULL; |
| 101 | } |
| 102 | |
| 103 | tmp[0] = 0x6a; |
| 104 | tmp[tmp_len - 1] = 0xbc; |
| 105 | |
| 106 | const unsigned char *rem; |
| 107 | size_t rem_len; |
| 108 | size_t hash_len = crypto_hash_get_size(ch); |
| 109 | size_t part_len = tmp_len - 2 - hash_len; |
| 110 | if (part_len < msg_len) { |
| 111 | memcpy(tmp + 1, msg, part_len); |
| 112 | rem = msg + part_len; |
| 113 | rem_len = msg_len - part_len; |
| 114 | } else { |
| 115 | memcpy(tmp + 1, msg, msg_len); |
| 116 | memset(tmp + 1 + msg_len, 0xbb, part_len - msg_len); |
| 117 | rem = NULL; |
| 118 | rem_len = 0; |
| 119 | } |
| 120 | crypto_hash_write(ch, tmp + 1, part_len); |
| 121 | crypto_hash_write(ch, rem, rem_len); |
| 122 | |
| 123 | va_list vl; |
| 124 | va_start(vl, msg_len); |
| 125 | while (true) { |
| 126 | const struct tlv *add_tlv = va_arg(vl, const struct tlv *); |
| 127 | if (!add_tlv) |
| 128 | break; |
| 129 | |
| 130 | crypto_hash_write(ch, add_tlv->value, add_tlv->len); |
| 131 | } |
| 132 | va_end(vl); |
| 133 | |
| 134 | unsigned char *h = crypto_hash_read(ch); |
| 135 | if (!h) { |
| 136 | crypto_hash_close(ch); |
| 137 | free(tmp); |
| 138 | |
| 139 | return NULL; |
| 140 | } |
| 141 | |
| 142 | memcpy(tmp + 1 + part_len, h, hash_len); |
| 143 | crypto_hash_close(ch); |
| 144 | |
| 145 | size_t cert_len; |
| 146 | unsigned char *cert = crypto_pk_decrypt(cp, tmp, tmp_len, &cert_len); |
| 147 | free(tmp); |
| 148 | |
| 149 | if (!cert) |
| 150 | return NULL; |
| 151 | |
| 152 | struct tlvdb *db = tlvdb_fixed(cert_tag, cert_len, cert); |
| 153 | free(cert); |
| 154 | if (!db) |
| 155 | return NULL; |
| 156 | |
| 157 | if (rem) { |
| 158 | struct tlvdb *rdb = tlvdb_fixed(rem_tag, rem_len, rem); |
| 159 | if (!rdb) { |
| 160 | tlvdb_free(db); |
| 161 | |
| 162 | return NULL; |
| 163 | } |
| 164 | tlvdb_add(db, rdb); |
| 165 | } |
| 166 | |
| 167 | return db; |
| 168 | } |
| 169 | |
| 170 | static struct tlvdb *emv_pki_sign_key(const struct crypto_pk *cp, |
| 171 | struct emv_pk *ipk, |
| 172 | unsigned char msgtype, |
| 173 | size_t pan_len, |
| 174 | tlv_tag_t cert_tag, |
| 175 | tlv_tag_t exp_tag, |
| 176 | tlv_tag_t rem_tag, |
| 177 | const struct tlv *add_tlv |
| 178 | ) |
| 179 | { |
| 180 | unsigned pos = 0; |
| 181 | unsigned char *msg = malloc(1 + pan_len + 2 + 3 + 1 + 1 + 1 + 1 + ipk->mlen); |
| 182 | |
| 183 | if (!msg) |
| 184 | return NULL; |
| 185 | |
| 186 | msg[pos++] = msgtype; |
| 187 | memcpy(msg + pos, ipk->pan, pan_len); pos += pan_len; |
| 188 | msg[pos++] = (ipk->expire >> 8) & 0xff; |
| 189 | msg[pos++] = (ipk->expire >> 16) & 0xff; |
| 190 | memcpy(msg + pos, ipk->serial, 3); pos += 3; |
| 191 | msg[pos++] = ipk->hash_algo; |
| 192 | msg[pos++] = ipk->pk_algo; |
| 193 | msg[pos++] = ipk->mlen; |
| 194 | msg[pos++] = ipk->elen; |
| 195 | memcpy(msg + pos, ipk->modulus, ipk->mlen); |
| 196 | pos += ipk->mlen; |
| 197 | |
| 198 | struct tlvdb *exp_db = tlvdb_fixed(exp_tag, ipk->elen, ipk->exp); |
| 199 | if (!exp_db) { |
| 200 | free(msg); |
| 201 | |
| 202 | return NULL; |
| 203 | } |
| 204 | |
| 205 | struct tlvdb *db = emv_pki_sign_message(cp, |
| 206 | cert_tag, rem_tag, |
| 207 | msg, pos, |
| 208 | tlvdb_get(exp_db, exp_tag, NULL), |
| 209 | add_tlv, |
| 210 | NULL); |
| 211 | free(msg); |
| 212 | if (!db) |
| 213 | return NULL; |
| 214 | |
| 215 | tlvdb_add(db, exp_db); |
| 216 | |
| 217 | return db; |
| 218 | } |
| 219 | |
| 220 | struct tlvdb *emv_pki_sign_issuer_cert(const struct crypto_pk *cp, struct emv_pk *issuer_pk) |
| 221 | { |
| 222 | return emv_pki_sign_key(cp, issuer_pk, 2, 4, 0x90, 0x9f32, 0x92, NULL); |
| 223 | } |
| 224 | |
| 225 | struct tlvdb *emv_pki_sign_icc_cert(const struct crypto_pk *cp, struct emv_pk *icc_pk, const struct tlv *sda_tlv) |
| 226 | { |
| 227 | return emv_pki_sign_key(cp, icc_pk, 4, 10, 0x9f46, 0x9f47, 0x9f48, sda_tlv); |
| 228 | } |
| 229 | |
| 230 | struct tlvdb *emv_pki_sign_icc_pe_cert(const struct crypto_pk *cp, struct emv_pk *icc_pe_pk) |
| 231 | { |
| 232 | return emv_pki_sign_key(cp, icc_pe_pk, 4, 10, 0x9f2d, 0x9f2e, 0x9f2f, NULL); |
| 233 | } |
| 234 | |
| 235 | struct tlvdb *emv_pki_sign_dac(const struct crypto_pk *cp, const struct tlv *dac_tlv, const struct tlv *sda_tlv) |
| 236 | { |
| 237 | unsigned pos = 0; |
| 238 | unsigned char *msg = malloc(1+1+dac_tlv->len); |
| 239 | |
| 240 | if (!msg) |
| 241 | return NULL; |
| 242 | |
| 243 | msg[pos++] = 3; |
| 244 | msg[pos++] = HASH_SHA_1; |
| 245 | memcpy(msg+pos, dac_tlv->value, dac_tlv->len); |
| 246 | pos += dac_tlv->len; |
| 247 | |
| 248 | struct tlvdb *db = emv_pki_sign_message(cp, |
| 249 | 0x93, 0, |
| 250 | msg, pos, |
| 251 | sda_tlv, |
| 252 | NULL); |
| 253 | |
| 254 | free(msg); |
| 255 | |
| 256 | return db; |
| 257 | } |
| 258 | |
| 259 | struct tlvdb *emv_pki_sign_idn(const struct crypto_pk *cp, const struct tlv *idn_tlv, const struct tlv *dyn_tlv) |
| 260 | { |
| 261 | unsigned pos = 0; |
| 262 | unsigned char *msg = malloc(1+1+1+1+idn_tlv->len); |
| 263 | |
| 264 | if (!msg) |
| 265 | return NULL; |
| 266 | |
| 267 | msg[pos++] = 5; |
| 268 | msg[pos++] = HASH_SHA_1; |
| 269 | msg[pos++] = idn_tlv->len + 1; |
| 270 | msg[pos++] = idn_tlv->len; |
| 271 | memcpy(msg+pos, idn_tlv->value, idn_tlv->len); |
| 272 | pos += idn_tlv->len; |
| 273 | |
| 274 | struct tlvdb *db = emv_pki_sign_message(cp, |
| 275 | 0x9f4b, 0, |
| 276 | msg, pos, |
| 277 | dyn_tlv, |
| 278 | NULL); |
| 279 | |
| 280 | free(msg); |
| 281 | |
| 282 | return db; |
| 283 | } |