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_rsa_private_key.h"
  18 #include "openssl_rsa_public_key.h"
  19
  20 #include <debug.h>
  21
  22 #include <openssl/evp.h>
  23 #include <openssl/rsa.h>
  24 #include <openssl/engine.h>
  25
  26 /**
  27  *  Public exponent to use for key generation.
  28  */
  29 #define PUBLIC_EXPONENT 0x10001
  30
  31 typedef struct private_openssl_rsa_private_key_t private_openssl_rsa_private_key_t;
  32
  33 /**
  34  * Private data of a openssl_rsa_private_key_t object.
  35  */
  36 struct private_openssl_rsa_private_key_t {
  37         /**
  38          * Public interface for this signer.
  39          */
  40         openssl_rsa_private_key_t public;
  41
  42         /**
  43          * RSA object from OpenSSL
  44          */
  45         RSA *rsa;
  46
  47         /**
  48          * TRUE if the key is from an OpenSSL ENGINE and might not be readable
  49          */
  50         bool engine;
  51
  52         /**
  53          * reference count
  54          */
  55         refcount_t ref;
  56 };
  57
  58 /* implemented in rsa public key */
  59 bool openssl_rsa_fingerprint(RSA *rsa, key_encoding_type_t type, chunk_t *fp);
  60
  61 /**
  62  * Build an EMPSA PKCS1 signature described in PKCS#1
  63  */
  64 static bool build_emsa_pkcs1_signature(private_openssl_rsa_private_key_t *this,
  65                                                                            int type, chunk_t data, chunk_t *sig)
  66 {
  67         bool success = FALSE;
  68
  69         *sig = chunk_alloc(RSA_size(this->rsa));
  70
  71         if (type == NID_undef)
  72         {
  73                 if (RSA_private_encrypt(data.len, data.ptr, sig->ptr, this->rsa,
  74                                                                 RSA_PKCS1_PADDING) == sig->len)
  75                 {
  76                         success = TRUE;
  77                 }
  78         }
  79         else
  80         {
  81                 EVP_MD_CTX *ctx;
  82                 EVP_PKEY *key;
  83                 const EVP_MD *hasher;
  84                 u_int len;
  85
  86                 hasher = EVP_get_digestbynid(type);
  87                 if (!hasher)
  88                 {
  89                         return FALSE;
  90                 }
  91
  92                 ctx = EVP_MD_CTX_create();
  93                 key = EVP_PKEY_new();
  94                 if (!ctx || !key)
  95                 {
  96                         goto error;
  97                 }
  98                 if (!EVP_PKEY_set1_RSA(key, this->rsa))
  99                 {
 100                         goto error;
 101                 }
 102                 if (!EVP_SignInit_ex(ctx, hasher, NULL))
 103                 {
 104                         goto error;
 105                 }
 106                 if (!EVP_SignUpdate(ctx, data.ptr, data.len))
 107                 {
 108                         goto error;
 109                 }
 110                 if (EVP_SignFinal(ctx, sig->ptr, &len, key))
 111                 {
 112                         success = TRUE;
 113                 }
 114
 115 error:
 116                 if (key)
 117                 {
 118                         EVP_PKEY_free(key);
 119                 }
 120                 if (ctx)
 121                 {
 122                         EVP_MD_CTX_destroy(ctx);
 123                 }
 124         }
 125         if (!success)
 126         {
 127                 free(sig->ptr);
 128         }
 129         return success;
 130 }
 131
 132 /**
 133  * Implementation of openssl_rsa_private_key.get_type.
 134  */
 135 static key_type_t get_type(private_openssl_rsa_private_key_t *this)
 136 {
 137         return KEY_RSA;
 138 }
 139
 140 /**
 141  * Implementation of openssl_rsa_private_key.sign.
 142  */
 143 static bool sign(private_openssl_rsa_private_key_t *this, signature_scheme_t scheme,
 144                                  chunk_t data, chunk_t *signature)
 145 {
 146         switch (scheme)
 147         {
 148                 case SIGN_RSA_EMSA_PKCS1_NULL:
 149                         return build_emsa_pkcs1_signature(this, NID_undef, data, signature);
 150                 case SIGN_RSA_EMSA_PKCS1_SHA1:
 151                         return build_emsa_pkcs1_signature(this, NID_sha1, data, signature);
 152                 case SIGN_RSA_EMSA_PKCS1_SHA224:
 153                         return build_emsa_pkcs1_signature(this, NID_sha224, data, signature);
 154                 case SIGN_RSA_EMSA_PKCS1_SHA256:
 155                         return build_emsa_pkcs1_signature(this, NID_sha256, data, signature);
 156                 case SIGN_RSA_EMSA_PKCS1_SHA384:
 157                         return build_emsa_pkcs1_signature(this, NID_sha384, data, signature);
 158                 case SIGN_RSA_EMSA_PKCS1_SHA512:
 159                         return build_emsa_pkcs1_signature(this, NID_sha512, data, signature);
 160                 case SIGN_RSA_EMSA_PKCS1_MD5:
 161                         return build_emsa_pkcs1_signature(this, NID_md5, data, signature);
 162                 default:
 163                         DBG1("signature scheme %N not supported in RSA",
 164                                  signature_scheme_names, scheme);
 165                         return FALSE;
 166         }
 167 }
 168
 169 /**
 170  * Implementation of openssl_rsa_private_key.decrypt.
 171  */
 172 static bool decrypt(private_openssl_rsa_private_key_t *this,
 173                                         chunk_t crypto, chunk_t *plain)
 174 {
 175         DBG1("RSA private key decryption not implemented");
 176         return FALSE;
 177 }
 178
 179 /**
 180  * Implementation of openssl_rsa_private_key.get_keysize.
 181  */
 182 static size_t get_keysize(private_openssl_rsa_private_key_t *this)
 183 {
 184         return RSA_size(this->rsa);
 185 }
 186
 187 /**
 188  * Implementation of openssl_rsa_private_key.get_public_key.
 189  */
 190 static public_key_t* get_public_key(private_openssl_rsa_private_key_t *this)
 191 {
 192         chunk_t enc;
 193         public_key_t *key;
 194         u_char *p;
 195
 196         enc = chunk_alloc(i2d_RSAPublicKey(this->rsa, NULL));
 197         p = enc.ptr;
 198         i2d_RSAPublicKey(this->rsa, &p);
 199         key = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_RSA,
 200                                                          BUILD_BLOB_ASN1_DER, enc, BUILD_END);
 201         free(enc.ptr);
 202         return key;
 203 }
 204
 205 /**
 206  * Implementation of public_key_t.get_fingerprint.
 207  */
 208 static bool get_fingerprint(private_openssl_rsa_private_key_t *this,
 209                                                         key_encoding_type_t type, chunk_t *fingerprint)
 210 {
 211         return openssl_rsa_fingerprint(this->rsa, type, fingerprint);
 212 }
 213
 214 /*
 215  * Implementation of public_key_t.get_encoding.
 216  */
 217 static bool get_encoding(private_openssl_rsa_private_key_t *this,
 218                                                  key_encoding_type_t type, chunk_t *encoding)
 219 {
 220         u_char *p;
 221
 222         if (this->engine)
 223         {
 224                 return FALSE;
 225         }
 226         switch (type)
 227         {
 228                 case KEY_PRIV_ASN1_DER:
 229                 {
 230                         *encoding = chunk_alloc(i2d_RSAPrivateKey(this->rsa, NULL));
 231                         p = encoding->ptr;
 232                         i2d_RSAPrivateKey(this->rsa, &p);
 233                         return TRUE;
 234                 }
 235                 default:
 236                         return FALSE;
 237         }
 238 }
 239
 240 /**
 241  * Implementation of openssl_rsa_private_key.get_ref.
 242  */
 243 static private_openssl_rsa_private_key_t* get_ref(private_openssl_rsa_private_key_t *this)
 244 {
 245         ref_get(&this->ref);
 246         return this;
 247 }
 248
 249 /**
 250  * Implementation of openssl_rsa_private_key.destroy.
 251  */
 252 static void destroy(private_openssl_rsa_private_key_t *this)
 253 {
 254         if (ref_put(&this->ref))
 255         {
 256                 if (this->rsa)
 257                 {
 258                         lib->encoding->clear_cache(lib->encoding, this->rsa);
 259                         RSA_free(this->rsa);
 260                 }
 261                 free(this);
 262         }
 263 }
 264
 265 /**
 266  * Internal generic constructor
 267  */
 268 static private_openssl_rsa_private_key_t *create_empty(void)
 269 {
 270         private_openssl_rsa_private_key_t *this = malloc_thing(private_openssl_rsa_private_key_t);
 271
 272         this->public.interface.get_type = (key_type_t (*) (private_key_t*))get_type;
 273         this->public.interface.sign = (bool (*) (private_key_t*, signature_scheme_t, chunk_t, chunk_t*))sign;
 274         this->public.interface.decrypt = (bool (*) (private_key_t*, chunk_t, chunk_t*))decrypt;
 275         this->public.interface.get_keysize = (size_t (*) (private_key_t*))get_keysize;
 276         this->public.interface.get_public_key = (public_key_t* (*) (private_key_t*))get_public_key;
 277         this->public.interface.equals = private_key_equals;
 278         this->public.interface.belongs_to = private_key_belongs_to;
 279         this->public.interface.get_fingerprint = (bool(*)(private_key_t*, key_encoding_type_t type, chunk_t *fp))get_fingerprint;
 280         this->public.interface.get_encoding = (bool(*)(private_key_t*, key_encoding_type_t type, chunk_t *encoding))get_encoding;
 281         this->public.interface.get_ref = (private_key_t* (*) (private_key_t*))get_ref;
 282         this->public.interface.destroy = (void (*) (private_key_t*))destroy;
 283
 284         this->engine = FALSE;
 285         this->ref = 1;
 286
 287         return this;
 288 }
 289
 290 /**
 291  * See header.
 292  */
 293 openssl_rsa_private_key_t *openssl_rsa_private_key_gen(key_type_t type,
 294                                                                                                            va_list args)
 295 {
 296         private_openssl_rsa_private_key_t *this;
 297         u_int key_size = 0;
 298
 299         while (TRUE)
 300         {
 301                 switch (va_arg(args, builder_part_t))
 302                 {
 303                         case BUILD_KEY_SIZE:
 304                                 key_size = va_arg(args, u_int);
 305                                 continue;
 306                         case BUILD_END:
 307                                 break;
 308                         default:
 309                                 return NULL;
 310                 }
 311                 break;
 312         }
 313         if (!key_size)
 314         {
 315                 return NULL;
 316         }
 317         this = create_empty();
 318         this->rsa = RSA_generate_key(key_size, PUBLIC_EXPONENT, NULL, NULL);
 319
 320         return &this->public;
 321 }
 322
 323 /**
 324  * See header
 325  */
 326 openssl_rsa_private_key_t *openssl_rsa_private_key_load(key_type_t type,
 327                                                                                                                 va_list args)
 328 {
 329         private_openssl_rsa_private_key_t *this;
 330         chunk_t blob = chunk_empty;
 331
 332         while (TRUE)
 333         {
 334                 switch (va_arg(args, builder_part_t))
 335                 {
 336                         case BUILD_BLOB_ASN1_DER:
 337                                 blob = va_arg(args, chunk_t);
 338                                 continue;
 339                         case BUILD_END:
 340                                 break;
 341                         default:
 342                                 return NULL;
 343                 }
 344                 break;
 345         }
 346
 347         this = create_empty();
 348         this->rsa = d2i_RSAPrivateKey(NULL, (const u_char**)&blob.ptr, blob.len);
 349         if (!this->rsa)
 350         {
 351                 destroy(this);
 352                 return NULL;
 353         }
 354         if (!RSA_check_key(this->rsa))
 355         {
 356                 destroy(this);
 357                 return NULL;
 358         }
 359         return &this->public;
 360 }
 361
 362 /**
 363  * See header.
 364  */
 365 openssl_rsa_private_key_t *openssl_rsa_private_key_connect(key_type_t type,
 366                                                                                                                    va_list args)
 367 {
 368         private_openssl_rsa_private_key_t *this;
 369         char *keyid = NULL, *pin = NULL;
 370         EVP_PKEY *key;
 371         char *engine_id;
 372         ENGINE *engine;
 373
 374         while (TRUE)
 375         {
 376                 switch (va_arg(args, builder_part_t))
 377                 {
 378                         case BUILD_SMARTCARD_KEYID:
 379                                 keyid = va_arg(args, char*);
 380                                 continue;
 381                         case BUILD_SMARTCARD_PIN:
 382                                 pin = va_arg(args, char*);
 383                                 continue;
 384                         case BUILD_END:
 385                                 break;
 386                         default:
 387                                 return NULL;
 388                 }
 389                 break;
 390         }
 391         if (!keyid || !pin)
 392         {
 393                 return NULL;
 394         }
 395
 396         engine_id = lib->settings->get_str(lib->settings,
 397                                                                 "library.plugins.openssl.engine_id", "pkcs11");
 398         engine = ENGINE_by_id(engine_id);
 399         if (!engine)
 400         {
 401                 DBG1("engine '%s' is not available", engine_id);
 402                 return NULL;
 403         }
 404         if (!ENGINE_init(engine))
 405         {
 406                 DBG1("failed to initialize engine '%s'", engine_id);
 407                 ENGINE_free(engine);
 408                 return NULL;
 409         }
 410         if (!ENGINE_ctrl_cmd_string(engine, "PIN", pin, 0))
 411         {
 412                 DBG1("failed to set PIN on engine '%s'", engine_id);
 413                 ENGINE_free(engine);
 414                 return NULL;
 415         }
 416
 417         key = ENGINE_load_private_key(engine, keyid, NULL, NULL);
 418         if (!key)
 419         {
 420                 DBG1("failed to load private key with ID '%s' from engine '%s'",
 421                          keyid, engine_id);
 422                 ENGINE_free(engine);
 423                 return NULL;
 424         }
 425         ENGINE_free(engine);
 426
 427         this = create_empty();
 428         this->rsa = EVP_PKEY_get1_RSA(key);
 429         this->engine = TRUE;
 430
 431         return &this->public;
 432 }
 433