src/libstrongswan/plugins/openssl/openssl_rsa_private_key.c

   1 /*
   2  * Copyright (C) 2009 Martin Willi
   3  * Copyright (C) 2008 Tobias Brunner
   4  * Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 #include <openssl/opensslconf.h>
  18
  19 #ifndef OPENSSL_NO_RSA
  20
  21 #include "openssl_rsa_private_key.h"
  22 #include "openssl_rsa_public_key.h"
  23
  24 #include <utils/debug.h>
  25
  26 #include <openssl/evp.h>
  27 #include <openssl/rsa.h>
  28 #ifndef OPENSSL_NO_ENGINE
  29 #include <openssl/engine.h>
  30 #endif /* OPENSSL_NO_ENGINE */
  31
  32 /**
  33  *  Public exponent to use for key generation.
  34  */
  35 #define PUBLIC_EXPONENT 0x10001
  36
  37 typedef struct private_openssl_rsa_private_key_t private_openssl_rsa_private_key_t;
  38
  39 /**
  40  * Private data of a openssl_rsa_private_key_t object.
  41  */
  42 struct private_openssl_rsa_private_key_t {
  43         /**
  44          * Public interface for this signer.
  45          */
  46         openssl_rsa_private_key_t public;
  47
  48         /**
  49          * RSA object from OpenSSL
  50          */
  51         RSA *rsa;
  52
  53         /**
  54          * TRUE if the key is from an OpenSSL ENGINE and might not be readable
  55          */
  56         bool engine;
  57
  58         /**
  59          * reference count
  60          */
  61         refcount_t ref;
  62 };
  63
  64 /* implemented in rsa public key */
  65 bool openssl_rsa_fingerprint(RSA *rsa, cred_encoding_type_t type, chunk_t *fp);
  66
  67 /**
  68  * Build an EMPSA PKCS1 signature described in PKCS#1
  69  */
  70 static bool build_emsa_pkcs1_signature(private_openssl_rsa_private_key_t *this,
  71                                                                            int type, chunk_t data, chunk_t *sig)
  72 {
  73         bool success = FALSE;
  74
  75         *sig = chunk_alloc(RSA_size(this->rsa));
  76
  77         if (type == NID_undef)
  78         {
  79                 if (RSA_private_encrypt(data.len, data.ptr, sig->ptr, this->rsa,
  80                                                                 RSA_PKCS1_PADDING) == sig->len)
  81                 {
  82                         success = TRUE;
  83                 }
  84         }
  85         else
  86         {
  87                 EVP_MD_CTX *ctx;
  88                 EVP_PKEY *key;
  89                 const EVP_MD *hasher;
  90                 u_int len;
  91
  92                 hasher = EVP_get_digestbynid(type);
  93                 if (!hasher)
  94                 {
  95                         return FALSE;
  96                 }
  97
  98                 ctx = EVP_MD_CTX_create();
  99                 key = EVP_PKEY_new();
 100                 if (!ctx || !key)
 101                 {
 102                         goto error;
 103                 }
 104                 if (!EVP_PKEY_set1_RSA(key, this->rsa))
 105                 {
 106                         goto error;
 107                 }
 108                 if (!EVP_SignInit_ex(ctx, hasher, NULL))
 109                 {
 110                         goto error;
 111                 }
 112                 if (!EVP_SignUpdate(ctx, data.ptr, data.len))
 113                 {
 114                         goto error;
 115                 }
 116                 if (EVP_SignFinal(ctx, sig->ptr, &len, key))
 117                 {
 118                         success = TRUE;
 119                 }
 120
 121 error:
 122                 if (key)
 123                 {
 124                         EVP_PKEY_free(key);
 125                 }
 126                 if (ctx)
 127                 {
 128                         EVP_MD_CTX_destroy(ctx);
 129                 }
 130         }
 131         if (!success)
 132         {
 133                 free(sig->ptr);
 134         }
 135         return success;
 136 }
 137
 138
 139 METHOD(private_key_t, get_type, key_type_t,
 140         private_openssl_rsa_private_key_t *this)
 141 {
 142         return KEY_RSA;
 143 }
 144
 145 METHOD(private_key_t, sign, bool,
 146         private_openssl_rsa_private_key_t *this, signature_scheme_t scheme,
 147         chunk_t data, chunk_t *signature)
 148 {
 149         switch (scheme)
 150         {
 151                 case SIGN_RSA_EMSA_PKCS1_NULL:
 152                         return build_emsa_pkcs1_signature(this, NID_undef, data, signature);
 153                 case SIGN_RSA_EMSA_PKCS1_SHA1:
 154                         return build_emsa_pkcs1_signature(this, NID_sha1, data, signature);
 155                 case SIGN_RSA_EMSA_PKCS1_SHA224:
 156                         return build_emsa_pkcs1_signature(this, NID_sha224, data, signature);
 157                 case SIGN_RSA_EMSA_PKCS1_SHA256:
 158                         return build_emsa_pkcs1_signature(this, NID_sha256, data, signature);
 159                 case SIGN_RSA_EMSA_PKCS1_SHA384:
 160                         return build_emsa_pkcs1_signature(this, NID_sha384, data, signature);
 161                 case SIGN_RSA_EMSA_PKCS1_SHA512:
 162                         return build_emsa_pkcs1_signature(this, NID_sha512, data, signature);
 163                 case SIGN_RSA_EMSA_PKCS1_MD5:
 164                         return build_emsa_pkcs1_signature(this, NID_md5, data, signature);
 165                 default:
 166                         DBG1(DBG_LIB, "signature scheme %N not supported in RSA",
 167                                  signature_scheme_names, scheme);
 168                         return FALSE;
 169         }
 170 }
 171
 172 METHOD(private_key_t, decrypt, bool,
 173         private_openssl_rsa_private_key_t *this, encryption_scheme_t scheme,
 174         chunk_t crypto, chunk_t *plain)
 175 {
 176         int padding, len;
 177         char *decrypted;
 178
 179         switch (scheme)
 180         {
 181                 case ENCRYPT_RSA_PKCS1:
 182                         padding = RSA_PKCS1_PADDING;
 183                         break;
 184                 case ENCRYPT_RSA_OAEP_SHA1:
 185                         padding = RSA_PKCS1_OAEP_PADDING;
 186                         break;
 187                 default:
 188                         DBG1(DBG_LIB, "encryption scheme %N not supported via openssl",
 189                                  encryption_scheme_names, scheme);
 190                         return FALSE;
 191         }
 192         decrypted = malloc(RSA_size(this->rsa));
 193         len = RSA_private_decrypt(crypto.len, crypto.ptr, decrypted,
 194                                                           this->rsa, padding);
 195         if (len < 0)
 196         {
 197                 DBG1(DBG_LIB, "RSA decryption failed");
 198                 free(decrypted);
 199                 return FALSE;
 200         }
 201         *plain = chunk_create(decrypted, len);
 202         return TRUE;
 203 }
 204
 205 METHOD(private_key_t, get_keysize, int,
 206         private_openssl_rsa_private_key_t *this)
 207 {
 208         return RSA_size(this->rsa) * 8;
 209 }
 210
 211 METHOD(private_key_t, get_public_key, public_key_t*,
 212         private_openssl_rsa_private_key_t *this)
 213 {
 214         chunk_t enc;
 215         public_key_t *key;
 216         u_char *p;
 217
 218         enc = chunk_alloc(i2d_RSAPublicKey(this->rsa, NULL));
 219         p = enc.ptr;
 220         i2d_RSAPublicKey(this->rsa, &p);
 221         key = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_RSA,
 222                                                          BUILD_BLOB_ASN1_DER, enc, BUILD_END);
 223         free(enc.ptr);
 224         return key;
 225 }
 226
 227 METHOD(private_key_t, get_fingerprint, bool,
 228         private_openssl_rsa_private_key_t *this, cred_encoding_type_t type,
 229         chunk_t *fingerprint)
 230 {
 231         return openssl_rsa_fingerprint(this->rsa, type, fingerprint);
 232 }
 233
 234 METHOD(private_key_t, get_encoding, bool,
 235         private_openssl_rsa_private_key_t *this, cred_encoding_type_t type,
 236         chunk_t *encoding)
 237 {
 238         u_char *p;
 239
 240         if (this->engine)
 241         {
 242                 return FALSE;
 243         }
 244         switch (type)
 245         {
 246                 case PRIVKEY_ASN1_DER:
 247                 case PRIVKEY_PEM:
 248                 {
 249                         bool success = TRUE;
 250
 251                         *encoding = chunk_alloc(i2d_RSAPrivateKey(this->rsa, NULL));
 252                         p = encoding->ptr;
 253                         i2d_RSAPrivateKey(this->rsa, &p);
 254
 255                         if (type == PRIVKEY_PEM)
 256                         {
 257                                 chunk_t asn1_encoding = *encoding;
 258
 259                                 success = lib->encoding->encode(lib->encoding, PRIVKEY_PEM,
 260                                                                 NULL, encoding, CRED_PART_RSA_PRIV_ASN1_DER,
 261                                                                 asn1_encoding, CRED_PART_END);
 262                                 chunk_clear(&asn1_encoding);
 263                         }
 264                         return success;
 265                 }
 266                 default:
 267                         return FALSE;
 268         }
 269 }
 270
 271 METHOD(private_key_t, get_ref, private_key_t*,
 272         private_openssl_rsa_private_key_t *this)
 273 {
 274         ref_get(&this->ref);
 275         return &this->public.key;
 276 }
 277
 278 METHOD(private_key_t, destroy, void,
 279         private_openssl_rsa_private_key_t *this)
 280 {
 281         if (ref_put(&this->ref))
 282         {
 283                 if (this->rsa)
 284                 {
 285                         lib->encoding->clear_cache(lib->encoding, this->rsa);
 286                         RSA_free(this->rsa);
 287                 }
 288                 free(this);
 289         }
 290 }
 291
 292 /**
 293  * Internal generic constructor
 294  */
 295 static private_openssl_rsa_private_key_t *create_empty()
 296 {
 297         private_openssl_rsa_private_key_t *this;
 298
 299         INIT(this,
 300                 .public = {
 301                         .key = {
 302                                 .get_type = _get_type,
 303                                 .sign = _sign,
 304                                 .decrypt = _decrypt,
 305                                 .get_keysize = _get_keysize,
 306                                 .get_public_key = _get_public_key,
 307                                 .equals = private_key_equals,
 308                                 .belongs_to = private_key_belongs_to,
 309                                 .get_fingerprint = _get_fingerprint,
 310                                 .has_fingerprint = private_key_has_fingerprint,
 311                                 .get_encoding = _get_encoding,
 312                                 .get_ref = _get_ref,
 313                                 .destroy = _destroy,
 314                         },
 315                 },
 316                 .ref = 1,
 317         );
 318
 319         return this;
 320 }
 321
 322 /**
 323  * See header.
 324  */
 325 openssl_rsa_private_key_t *openssl_rsa_private_key_gen(key_type_t type,
 326                                                                                                            va_list args)
 327 {
 328         private_openssl_rsa_private_key_t *this;
 329         u_int key_size = 0;
 330         RSA *rsa = NULL;
 331         BIGNUM *e = NULL;
 332
 333         while (TRUE)
 334         {
 335                 switch (va_arg(args, builder_part_t))
 336                 {
 337                         case BUILD_KEY_SIZE:
 338                                 key_size = va_arg(args, u_int);
 339                                 continue;
 340                         case BUILD_END:
 341                                 break;
 342                         default:
 343                                 return NULL;
 344                 }
 345                 break;
 346         }
 347         if (!key_size)
 348         {
 349                 return NULL;
 350         }
 351         e = BN_new();
 352         if (!e || !BN_set_word(e, PUBLIC_EXPONENT))
 353         {
 354                 goto error;
 355         }
 356         rsa = RSA_new();
 357         if (!rsa || !RSA_generate_key_ex(rsa, key_size, e, NULL))
 358         {
 359                 goto error;
 360         }
 361         this = create_empty();
 362         this->rsa = rsa;
 363         BN_free(e);
 364         return &this->public;
 365
 366 error:
 367         if (e)
 368         {
 369                 BN_free(e);
 370         }
 371         if (rsa)
 372         {
 373                 RSA_free(rsa);
 374         }
 375         return NULL;
 376 }
 377
 378 /**
 379  * See header
 380  */
 381 openssl_rsa_private_key_t *openssl_rsa_private_key_load(key_type_t type,
 382                                                                                                                 va_list args)
 383 {
 384         private_openssl_rsa_private_key_t *this;
 385         chunk_t blob, n, e, d, p, q, exp1, exp2, coeff;
 386
 387         blob = n = e = d = p = q = exp1 = exp2 = coeff = chunk_empty;
 388         while (TRUE)
 389         {
 390                 switch (va_arg(args, builder_part_t))
 391                 {
 392                         case BUILD_BLOB_ASN1_DER:
 393                                 blob = va_arg(args, chunk_t);
 394                                 continue;
 395                         case BUILD_RSA_MODULUS:
 396                                 n = va_arg(args, chunk_t);
 397                                 continue;
 398                         case BUILD_RSA_PUB_EXP:
 399                                 e = va_arg(args, chunk_t);
 400                                 continue;
 401                         case BUILD_RSA_PRIV_EXP:
 402                                 d = va_arg(args, chunk_t);
 403                                 continue;
 404                         case BUILD_RSA_PRIME1:
 405                                 p = va_arg(args, chunk_t);
 406                                 continue;
 407                         case BUILD_RSA_PRIME2:
 408                                 q = va_arg(args, chunk_t);
 409                                 continue;
 410                         case BUILD_RSA_EXP1:
 411                                 exp1 = va_arg(args, chunk_t);
 412                                 continue;
 413                         case BUILD_RSA_EXP2:
 414                                 exp2 = va_arg(args, chunk_t);
 415                                 continue;
 416                         case BUILD_RSA_COEFF:
 417                                 coeff = va_arg(args, chunk_t);
 418                                 continue;
 419                         case BUILD_END:
 420                                 break;
 421                         default:
 422                                 return NULL;
 423                 }
 424                 break;
 425         }
 426
 427         this = create_empty();
 428         if (blob.ptr)
 429         {
 430                 this->rsa = d2i_RSAPrivateKey(NULL, (const u_char**)&blob.ptr, blob.len);
 431                 if (this->rsa && RSA_check_key(this->rsa))
 432                 {
 433                         return &this->public;
 434                 }
 435         }
 436         else if (n.ptr && e.ptr && d.ptr && p.ptr && q.ptr && coeff.ptr)
 437         {
 438                 this->rsa = RSA_new();
 439                 this->rsa->n = BN_bin2bn((const u_char*)n.ptr, n.len, NULL);
 440                 this->rsa->e = BN_bin2bn((const u_char*)e.ptr, e.len, NULL);
 441                 this->rsa->d = BN_bin2bn((const u_char*)d.ptr, d.len, NULL);
 442                 this->rsa->p = BN_bin2bn((const u_char*)p.ptr, p.len, NULL);
 443                 this->rsa->q = BN_bin2bn((const u_char*)q.ptr, q.len, NULL);
 444                 if (exp1.ptr)
 445                 {
 446                         this->rsa->dmp1 = BN_bin2bn((const u_char*)exp1.ptr, exp1.len, NULL);
 447                 }
 448                 if (exp2.ptr)
 449                 {
 450                         this->rsa->dmq1 = BN_bin2bn((const u_char*)exp2.ptr, exp2.len, NULL);
 451                 }
 452                 this->rsa->iqmp = BN_bin2bn((const u_char*)coeff.ptr, coeff.len, NULL);
 453                 if (RSA_check_key(this->rsa))
 454                 {
 455                         return &this->public;
 456                 }
 457         }
 458         destroy(this);
 459         return NULL;
 460 }
 461
 462 #ifndef OPENSSL_NO_ENGINE
 463 /**
 464  * Login to engine with a PIN specified for a keyid
 465  */
 466 static bool login(ENGINE *engine, chunk_t keyid)
 467 {
 468         enumerator_t *enumerator;
 469         shared_key_t *shared;
 470         identification_t *id;
 471         chunk_t key;
 472         char pin[64];
 473         bool found = FALSE, success = FALSE;
 474
 475         id = identification_create_from_encoding(ID_KEY_ID, keyid);
 476         enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
 477                                                                                                                 SHARED_PIN, id, NULL);
 478         while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
 479         {
 480                 found = TRUE;
 481                 key = shared->get_key(shared);
 482                 if (snprintf(pin, sizeof(pin),
 483                                          "%.*s", (int)key.len, key.ptr) >= sizeof(pin))
 484                 {
 485                         continue;
 486                 }
 487                 if (ENGINE_ctrl_cmd_string(engine, "PIN", pin, 0))
 488                 {
 489                         success = TRUE;
 490                         break;
 491                 }
 492                 else
 493                 {
 494                         DBG1(DBG_CFG, "setting PIN on engine failed");
 495                 }
 496         }
 497         enumerator->destroy(enumerator);
 498         id->destroy(id);
 499         if (!found)
 500         {
 501                 DBG1(DBG_CFG, "no PIN found for %#B", &keyid);
 502         }
 503         return success;
 504 }
 505 #endif /* OPENSSL_NO_ENGINE */
 506
 507 /**
 508  * See header.
 509  */
 510 openssl_rsa_private_key_t *openssl_rsa_private_key_connect(key_type_t type,
 511                                                                                                                    va_list args)
 512 {
 513 #ifndef OPENSSL_NO_ENGINE
 514         private_openssl_rsa_private_key_t *this;
 515         char *engine_id = NULL;
 516         char keyname[64];
 517         chunk_t keyid = chunk_empty;;
 518         EVP_PKEY *key;
 519         ENGINE *engine;
 520         int slot = -1;
 521
 522         while (TRUE)
 523         {
 524                 switch (va_arg(args, builder_part_t))
 525                 {
 526                         case BUILD_PKCS11_KEYID:
 527                                 keyid = va_arg(args, chunk_t);
 528                                 continue;
 529                         case BUILD_PKCS11_SLOT:
 530                                 slot = va_arg(args, int);
 531                                 continue;
 532                         case BUILD_PKCS11_MODULE:
 533                                 engine_id = va_arg(args, char*);
 534                                 continue;
 535                         case BUILD_END:
 536                                 break;
 537                         default:
 538                                 return NULL;
 539                 }
 540                 break;
 541         }
 542         if (!keyid.len || keyid.len > 40)
 543         {
 544                 return NULL;
 545         }
 546
 547         memset(keyname, 0, sizeof(keyname));
 548         if (slot != -1)
 549         {
 550                 snprintf(keyname, sizeof(keyname), "%d:", slot);
 551         }
 552         if (sizeof(keyname) - strlen(keyname) <= keyid.len * 4 / 3 + 1)
 553         {
 554                 return NULL;
 555         }
 556         chunk_to_hex(keyid, keyname + strlen(keyname), FALSE);
 557
 558         if (!engine_id)
 559         {
 560                 engine_id = lib->settings->get_str(lib->settings,
 561                                                 "libstrongswan.plugins.openssl.engine_id", "pkcs11");
 562         }
 563         engine = ENGINE_by_id(engine_id);
 564         if (!engine)
 565         {
 566                 DBG2(DBG_LIB, "engine '%s' is not available", engine_id);
 567                 return NULL;
 568         }
 569         if (!ENGINE_init(engine))
 570         {
 571                 DBG1(DBG_LIB, "failed to initialize engine '%s'", engine_id);
 572                 ENGINE_free(engine);
 573                 return NULL;
 574         }
 575         if (!login(engine, keyid))
 576         {
 577                 DBG1(DBG_LIB, "login to engine '%s' failed", engine_id);
 578                 ENGINE_free(engine);
 579                 return NULL;
 580         }
 581         key = ENGINE_load_private_key(engine, keyname, NULL, NULL);
 582         if (!key)
 583         {
 584                 DBG1(DBG_LIB, "failed to load private key with ID '%s' from "
 585                          "engine '%s'", keyname, engine_id);
 586                 ENGINE_free(engine);
 587                 return NULL;
 588         }
 589         ENGINE_free(engine);
 590
 591         this = create_empty();
 592         this->rsa = EVP_PKEY_get1_RSA(key);
 593         this->engine = TRUE;
 594         if (!this->rsa)
 595         {
 596                 destroy(this);
 597                 return NULL;
 598         }
 599
 600         return &this->public;
 601 #else /* OPENSSL_NO_ENGINE */
 602         return NULL;
 603 #endif /* OPENSSL_NO_ENGINE */
 604 }
 605
 606 #endif /* OPENSSL_NO_RSA */