crypto/openssh-4/scard-opensc.c

   1 /*
   2  * Copyright (c) 2002 Juha Yrjölä.  All rights reserved.
   3  * Copyright (c) 2001 Markus Friedl.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "includes.h"
  27 #if defined(SMARTCARD) && defined(USE_OPENSC)
  28
  29 #include <sys/types.h>
  30
  31 #include <openssl/evp.h>
  32 #include <openssl/x509.h>
  33
  34 #include <stdarg.h>
  35
  36 #include <opensc/opensc.h>
  37 #include <opensc/pkcs15.h>
  38
  39 #include "key.h"
  40 #include "log.h"
  41 #include "xmalloc.h"
  42 #include "misc.h"
  43 #include "scard.h"
  44
  45 #if OPENSSL_VERSION_NUMBER < 0x00907000L && defined(CRYPTO_LOCK_ENGINE)
  46 #define USE_ENGINE
  47 #define RSA_get_default_method RSA_get_default_openssl_method
  48 #else
  49 #endif
  50
  51 #ifdef USE_ENGINE
  52 #include <openssl/engine.h>
  53 #define sc_get_rsa sc_get_engine
  54 #else
  55 #define sc_get_rsa sc_get_rsa_method
  56 #endif
  57
  58 static int sc_reader_id;
  59 static sc_context_t *ctx = NULL;
  60 static sc_card_t *card = NULL;
  61 static sc_pkcs15_card_t *p15card = NULL;
  62
  63 static char *sc_pin = NULL;
  64
  65 struct sc_priv_data
  66 {
  67         struct sc_pkcs15_id cert_id;
  68         int ref_count;
  69 };
  70
  71 void
  72 sc_close(void)
  73 {
  74         if (p15card) {
  75                 sc_pkcs15_unbind(p15card);
  76                 p15card = NULL;
  77         }
  78         if (card) {
  79                 sc_disconnect_card(card, 0);
  80                 card = NULL;
  81         }
  82         if (ctx) {
  83                 sc_release_context(ctx);
  84                 ctx = NULL;
  85         }
  86 }
  87
  88 static int
  89 sc_init(void)
  90 {
  91         int r;
  92
  93         r = sc_establish_context(&ctx, "openssh");
  94         if (r)
  95                 goto err;
  96         if (sc_reader_id >= ctx->reader_count) {
  97                 r = SC_ERROR_NO_READERS_FOUND;
  98                 error("Illegal reader number %d (max %d)", sc_reader_id,
  99                     ctx->reader_count -1);
 100                 goto err;
 101         }
 102         r = sc_connect_card(ctx->reader[sc_reader_id], 0, &card);
 103         if (r)
 104                 goto err;
 105         r = sc_pkcs15_bind(card, &p15card);
 106         if (r)
 107                 goto err;
 108         return 0;
 109 err:
 110         sc_close();
 111         return r;
 112 }
 113
 114 /* private key operations */
 115
 116 static int
 117 sc_prkey_op_init(RSA *rsa, struct sc_pkcs15_object **key_obj_out,
 118         unsigned int usage)
 119 {
 120         int r;
 121         struct sc_priv_data *priv;
 122         struct sc_pkcs15_object *key_obj;
 123         struct sc_pkcs15_prkey_info *key;
 124         struct sc_pkcs15_object *pin_obj;
 125         struct sc_pkcs15_pin_info *pin;
 126
 127         priv = (struct sc_priv_data *) RSA_get_app_data(rsa);
 128         if (priv == NULL)
 129                 return -1;
 130         if (p15card == NULL) {
 131                 sc_close();
 132                 r = sc_init();
 133                 if (r) {
 134                         error("SmartCard init failed: %s", sc_strerror(r));
 135                         goto err;
 136                 }
 137         }
 138         r = sc_pkcs15_find_prkey_by_id_usage(p15card, &priv->cert_id,
 139                 usage, &key_obj);
 140         if (r) {
 141                 error("Unable to find private key from SmartCard: %s",
 142                       sc_strerror(r));
 143                 goto err;
 144         }
 145         key = key_obj->data;
 146         r = sc_pkcs15_find_pin_by_auth_id(p15card, &key_obj->auth_id,
 147                                           &pin_obj);
 148         if (r == SC_ERROR_OBJECT_NOT_FOUND) {
 149                 /* no pin required */
 150                 r = sc_lock(card);
 151                 if (r) {
 152                         error("Unable to lock smartcard: %s", sc_strerror(r));
 153                         goto err;
 154                 }
 155                 *key_obj_out = key_obj;
 156                 return 0;
 157         } else if (r) {
 158                 error("Unable to find PIN object from SmartCard: %s",
 159                       sc_strerror(r));
 160                 goto err;
 161         }
 162         pin = pin_obj->data;
 163         r = sc_lock(card);
 164         if (r) {
 165                 error("Unable to lock smartcard: %s", sc_strerror(r));
 166                 goto err;
 167         }
 168         if (sc_pin != NULL) {
 169                 r = sc_pkcs15_verify_pin(p15card, pin, sc_pin,
 170                                          strlen(sc_pin));
 171                 if (r) {
 172                         sc_unlock(card);
 173                         error("PIN code verification failed: %s",
 174                               sc_strerror(r));
 175                         goto err;
 176                 }
 177         }
 178         *key_obj_out = key_obj;
 179         return 0;
 180 err:
 181         sc_close();
 182         return -1;
 183 }
 184
 185 #define SC_USAGE_DECRYPT        SC_PKCS15_PRKEY_USAGE_DECRYPT | \
 186                                 SC_PKCS15_PRKEY_USAGE_UNWRAP
 187
 188 static int
 189 sc_private_decrypt(int flen, u_char *from, u_char *to, RSA *rsa,
 190     int padding)
 191 {
 192         struct sc_pkcs15_object *key_obj;
 193         int r;
 194
 195         if (padding != RSA_PKCS1_PADDING)
 196                 return -1;
 197         r = sc_prkey_op_init(rsa, &key_obj, SC_USAGE_DECRYPT);
 198         if (r)
 199                 return -1;
 200         r = sc_pkcs15_decipher(p15card, key_obj, SC_ALGORITHM_RSA_PAD_PKCS1,
 201             from, flen, to, flen);
 202         sc_unlock(card);
 203         if (r < 0) {
 204                 error("sc_pkcs15_decipher() failed: %s", sc_strerror(r));
 205                 goto err;
 206         }
 207         return r;
 208 err:
 209         sc_close();
 210         return -1;
 211 }
 212
 213 #define SC_USAGE_SIGN           SC_PKCS15_PRKEY_USAGE_SIGN | \
 214                                 SC_PKCS15_PRKEY_USAGE_SIGNRECOVER
 215
 216 static int
 217 sc_sign(int type, u_char *m, unsigned int m_len,
 218         unsigned char *sigret, unsigned int *siglen, RSA *rsa)
 219 {
 220         struct sc_pkcs15_object *key_obj;
 221         int r;
 222         unsigned long flags = 0;
 223
 224         /* XXX: sc_prkey_op_init will search for a pkcs15 private
 225          * key object with the sign or signrecover usage flag set.
 226          * If the signing key has only the non-repudiation flag set
 227          * the key will be rejected as using a non-repudiation key
 228          * for authentication is not recommended. Note: This does not
 229          * prevent the use of a non-repudiation key for authentication
 230          * if the sign or signrecover flag is set as well.
 231          */
 232         r = sc_prkey_op_init(rsa, &key_obj, SC_USAGE_SIGN);
 233         if (r)
 234                 return -1;
 235         /* FIXME: length of sigret correct? */
 236         /* FIXME: check 'type' and modify flags accordingly */
 237         flags = SC_ALGORITHM_RSA_PAD_PKCS1 | SC_ALGORITHM_RSA_HASH_SHA1;
 238         r = sc_pkcs15_compute_signature(p15card, key_obj, flags,
 239                                         m, m_len, sigret, RSA_size(rsa));
 240         sc_unlock(card);
 241         if (r < 0) {
 242                 error("sc_pkcs15_compute_signature() failed: %s",
 243                       sc_strerror(r));
 244                 goto err;
 245         }
 246         *siglen = r;
 247         return 1;
 248 err:
 249         sc_close();
 250         return 0;
 251 }
 252
 253 static int
 254 sc_private_encrypt(int flen, u_char *from, u_char *to, RSA *rsa,
 255     int padding)
 256 {
 257         error("Private key encryption not supported");
 258         return -1;
 259 }
 260
 261 /* called on free */
 262
 263 static int (*orig_finish)(RSA *rsa) = NULL;
 264
 265 static int
 266 sc_finish(RSA *rsa)
 267 {
 268         struct sc_priv_data *priv;
 269
 270         priv = RSA_get_app_data(rsa);
 271         priv->ref_count--;
 272         if (priv->ref_count == 0) {
 273                 free(priv);
 274                 sc_close();
 275         }
 276         if (orig_finish)
 277                 orig_finish(rsa);
 278         return 1;
 279 }
 280
 281 /* engine for overloading private key operations */
 282
 283 static RSA_METHOD *
 284 sc_get_rsa_method(void)
 285 {
 286         static RSA_METHOD smart_rsa;
 287         const RSA_METHOD *def = RSA_get_default_method();
 288
 289         /* use the OpenSSL version */
 290         memcpy(&smart_rsa, def, sizeof(smart_rsa));
 291
 292         smart_rsa.name          = "opensc";
 293
 294         /* overload */
 295         smart_rsa.rsa_priv_enc  = sc_private_encrypt;
 296         smart_rsa.rsa_priv_dec  = sc_private_decrypt;
 297         smart_rsa.rsa_sign      = sc_sign;
 298
 299         /* save original */
 300         orig_finish             = def->finish;
 301         smart_rsa.finish        = sc_finish;
 302
 303         return &smart_rsa;
 304 }
 305
 306 #ifdef USE_ENGINE
 307 static ENGINE *
 308 sc_get_engine(void)
 309 {
 310         static ENGINE *smart_engine = NULL;
 311
 312         if ((smart_engine = ENGINE_new()) == NULL)
 313                 fatal("ENGINE_new failed");
 314
 315         ENGINE_set_id(smart_engine, "opensc");
 316         ENGINE_set_name(smart_engine, "OpenSC");
 317
 318         ENGINE_set_RSA(smart_engine, sc_get_rsa_method());
 319         ENGINE_set_DSA(smart_engine, DSA_get_default_openssl_method());
 320         ENGINE_set_DH(smart_engine, DH_get_default_openssl_method());
 321         ENGINE_set_RAND(smart_engine, RAND_SSLeay());
 322         ENGINE_set_BN_mod_exp(smart_engine, BN_mod_exp);
 323
 324         return smart_engine;
 325 }
 326 #endif
 327
 328 static void
 329 convert_rsa_to_rsa1(Key * in, Key * out)
 330 {
 331         struct sc_priv_data *priv;
 332
 333         out->rsa->flags = in->rsa->flags;
 334         out->flags = in->flags;
 335         RSA_set_method(out->rsa, RSA_get_method(in->rsa));
 336         BN_copy(out->rsa->n, in->rsa->n);
 337         BN_copy(out->rsa->e, in->rsa->e);
 338         priv = RSA_get_app_data(in->rsa);
 339         priv->ref_count++;
 340         RSA_set_app_data(out->rsa, priv);
 341         return;
 342 }
 343
 344 static int
 345 sc_read_pubkey(Key * k, const struct sc_pkcs15_object *cert_obj)
 346 {
 347         int r;
 348         sc_pkcs15_cert_t *cert = NULL;
 349         struct sc_priv_data *priv = NULL;
 350         sc_pkcs15_cert_info_t *cinfo = cert_obj->data;
 351
 352         X509 *x509 = NULL;
 353         EVP_PKEY *pubkey = NULL;
 354         u8 *p;
 355         char *tmp;
 356
 357         debug("sc_read_pubkey() with cert id %02X", cinfo->id.value[0]);
 358         r = sc_pkcs15_read_certificate(p15card, cinfo, &cert);
 359         if (r) {
 360                 logit("Certificate read failed: %s", sc_strerror(r));
 361                 goto err;
 362         }
 363         x509 = X509_new();
 364         if (x509 == NULL) {
 365                 r = -1;
 366                 goto err;
 367         }
 368         p = cert->data;
 369         if (!d2i_X509(&x509, &p, cert->data_len)) {
 370                 logit("Unable to parse X.509 certificate");
 371                 r = -1;
 372                 goto err;
 373         }
 374         sc_pkcs15_free_certificate(cert);
 375         cert = NULL;
 376         pubkey = X509_get_pubkey(x509);
 377         X509_free(x509);
 378         x509 = NULL;
 379         if (pubkey->type != EVP_PKEY_RSA) {
 380                 logit("Public key is of unknown type");
 381                 r = -1;
 382                 goto err;
 383         }
 384         k->rsa = EVP_PKEY_get1_RSA(pubkey);
 385         EVP_PKEY_free(pubkey);
 386
 387         k->rsa->flags |= RSA_FLAG_SIGN_VER;
 388         RSA_set_method(k->rsa, sc_get_rsa_method());
 389         priv = xmalloc(sizeof(struct sc_priv_data));
 390         priv->cert_id = cinfo->id;
 391         priv->ref_count = 1;
 392         RSA_set_app_data(k->rsa, priv);
 393
 394         k->flags = KEY_FLAG_EXT;
 395         tmp = key_fingerprint(k, SSH_FP_MD5, SSH_FP_HEX);
 396         debug("fingerprint %d %s", key_size(k), tmp);
 397         xfree(tmp);
 398
 399         return 0;
 400 err:
 401         if (cert)
 402                 sc_pkcs15_free_certificate(cert);
 403         if (pubkey)
 404                 EVP_PKEY_free(pubkey);
 405         if (x509)
 406                 X509_free(x509);
 407         return r;
 408 }
 409
 410 Key **
 411 sc_get_keys(const char *id, const char *pin)
 412 {
 413         Key *k, **keys;
 414         int i, r, real_count = 0, key_count;
 415         sc_pkcs15_id_t cert_id;
 416         sc_pkcs15_object_t *certs[32];
 417         char *buf = xstrdup(id), *p;
 418
 419         debug("sc_get_keys called: id = %s", id);
 420
 421         if (sc_pin != NULL)
 422                 xfree(sc_pin);
 423         sc_pin = (pin == NULL) ? NULL : xstrdup(pin);
 424
 425         cert_id.len = 0;
 426         if ((p = strchr(buf, ':')) != NULL) {
 427                 *p = 0;
 428                 p++;
 429                 sc_pkcs15_hex_string_to_id(p, &cert_id);
 430         }
 431         r = sscanf(buf, "%d", &sc_reader_id);
 432         xfree(buf);
 433         if (r != 1)
 434                 goto err;
 435         if (p15card == NULL) {
 436                 sc_close();
 437                 r = sc_init();
 438                 if (r) {
 439                         error("Smartcard init failed: %s", sc_strerror(r));
 440                         goto err;
 441                 }
 442         }
 443         if (cert_id.len) {
 444                 r = sc_pkcs15_find_cert_by_id(p15card, &cert_id, &certs[0]);
 445                 if (r < 0)
 446                         goto err;
 447                 key_count = 1;
 448         } else {
 449                 r = sc_pkcs15_get_objects(p15card, SC_PKCS15_TYPE_CERT_X509,
 450                                           certs, 32);
 451                 if (r == 0) {
 452                         logit("No certificates found on smartcard");
 453                         r = -1;
 454                         goto err;
 455                 } else if (r < 0) {
 456                         error("Certificate enumeration failed: %s",
 457                               sc_strerror(r));
 458                         goto err;
 459                 }
 460                 key_count = r;
 461         }
 462         if (key_count > 1024)
 463                 fatal("Too many keys (%u), expected <= 1024", key_count);
 464         keys = xcalloc(key_count * 2 + 1, sizeof(Key *));
 465         for (i = 0; i < key_count; i++) {
 466                 sc_pkcs15_object_t *tmp_obj = NULL;
 467                 cert_id = ((sc_pkcs15_cert_info_t *)(certs[i]->data))->id;
 468                 if (sc_pkcs15_find_prkey_by_id(p15card, &cert_id, &tmp_obj))
 469                         /* skip the public key (certificate) if no
 470                          * corresponding private key is present */
 471                         continue;
 472                 k = key_new(KEY_RSA);
 473                 if (k == NULL)
 474                         break;
 475                 r = sc_read_pubkey(k, certs[i]);
 476                 if (r) {
 477                         error("sc_read_pubkey failed: %s", sc_strerror(r));
 478                         key_free(k);
 479                         continue;
 480                 }
 481                 keys[real_count] = k;
 482                 real_count++;
 483                 k = key_new(KEY_RSA1);
 484                 if (k == NULL)
 485                         break;
 486                 convert_rsa_to_rsa1(keys[real_count-1], k);
 487                 keys[real_count] = k;
 488                 real_count++;
 489         }
 490         keys[real_count] = NULL;
 491
 492         return keys;
 493 err:
 494         sc_close();
 495         return NULL;
 496 }
 497
 498 int
 499 sc_put_key(Key *prv, const char *id)
 500 {
 501         error("key uploading not yet supported");
 502         return -1;
 503 }
 504
 505 char *
 506 sc_get_key_label(Key *key)
 507 {
 508         int r;
 509         const struct sc_priv_data *priv;
 510         struct sc_pkcs15_object *key_obj;
 511
 512         priv = (const struct sc_priv_data *) RSA_get_app_data(key->rsa);
 513         if (priv == NULL || p15card == NULL) {
 514                 logit("SmartCard key not loaded");
 515                 /* internal error => return default label */
 516                 return xstrdup("smartcard key");
 517         }
 518         r = sc_pkcs15_find_prkey_by_id(p15card, &priv->cert_id, &key_obj);
 519         if (r) {
 520                 logit("Unable to find private key from SmartCard: %s",
 521                       sc_strerror(r));
 522                 return xstrdup("smartcard key");
 523         }
 524         if (key_obj == NULL || key_obj->label == NULL)
 525                 /* the optional PKCS#15 label does not exists
 526                  * => return the default label */
 527                 return xstrdup("smartcard key");
 528         return xstrdup(key_obj->label);
 529 }
 530
 531 #endif /* SMARTCARD */