Extract PKCS#5 handling from pkcs8 plugin to separate helper class
[strongswan.git] / src / libstrongswan / plugins / pkcs8 / pkcs8_builder.c
index 26a3620..e93a836 100644 (file)
@@ -19,6 +19,7 @@
 #include <asn1/oid.h>
 #include <asn1/asn1.h>
 #include <asn1/asn1_parser.h>
+#include <crypto/pkcs5.h>
 #include <credentials/keys/private_key.h>
 
 /**
@@ -101,450 +102,39 @@ end:
 }
 
 /**
- * Verify padding of decrypted blob.
- * Length of blob is adjusted accordingly.
- */
-static bool verify_padding(chunk_t *blob)
-{
-       u_int8_t padding, count;
-
-       padding = count = blob->ptr[blob->len - 1];
-       if (padding > 8)
-       {
-               return FALSE;
-       }
-       for (; blob->len && count; --blob->len, --count)
-       {
-               if (blob->ptr[blob->len - 1] != padding)
-               {
-                       return FALSE;
-               }
-       }
-       return TRUE;
-}
-
-/**
- * Prototype for key derivation functions.
- */
-typedef bool (*kdf_t)(void *generator, chunk_t password, chunk_t salt,
-                                         u_int64_t iterations, chunk_t key);
-
-/**
  * Try to decrypt the given blob with multiple passwords using the given
- * key derivation function. keymat is where the kdf function writes the key
- * to, key and iv point to the actual keys and initialization vectors resp.
+ * pkcs5 object.
  */
-static private_key_t *decrypt_private_key(chunk_t blob,
-                                       encryption_algorithm_t encr, size_t key_len, kdf_t kdf,
-                                       void *generator, chunk_t salt, u_int64_t iterations,
-                                       chunk_t keymat, chunk_t key, chunk_t iv)
+static private_key_t *decrypt_private_key(pkcs5_t *pkcs5, chunk_t blob)
 {
        enumerator_t *enumerator;
        shared_key_t *shared;
-       crypter_t *crypter;
        private_key_t *private_key = NULL;
 
-       crypter = lib->crypto->create_crypter(lib->crypto, encr, key_len);
-       if (!crypter)
-       {
-               DBG1(DBG_ASN, "  %N encryption algorithm not available",
-                        encryption_algorithm_names, encr);
-               return NULL;
-       }
-       if (blob.len % crypter->get_block_size(crypter))
-       {
-               DBG1(DBG_ASN, "  data size is not a multiple of block size");
-               crypter->destroy(crypter);
-               return NULL;
-       }
-
        enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
                                                                                SHARED_PRIVATE_KEY_PASS, NULL, NULL);
        while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
        {
                chunk_t decrypted;
 
-               if (!kdf(generator, shared->get_key(shared), salt, iterations, keymat))
-               {
-                       continue;
-               }
-               if (!crypter->set_key(crypter, key) ||
-                       !crypter->decrypt(crypter, blob, iv, &decrypted))
+               if (!pkcs5->decrypt(pkcs5, shared->get_key(shared), blob, &decrypted))
                {
                        continue;
                }
-               if (verify_padding(&decrypted))
+               private_key = parse_private_key(decrypted);
+               if (private_key)
                {
-                       private_key = parse_private_key(decrypted);
-                       if (private_key)
-                       {
-                               chunk_clear(&decrypted);
-                               break;
-                       }
+                       chunk_clear(&decrypted);
+                       break;
                }
                chunk_free(&decrypted);
        }
        enumerator->destroy(enumerator);
-       crypter->destroy(crypter);
-
-       return private_key;
-}
-
-/**
- * Function F of PBKDF2
- */
-static bool pbkdf2_f(chunk_t block, prf_t *prf, chunk_t seed,
-                                        u_int64_t iterations)
-{
-       chunk_t u;
-       u_int64_t i;
-
-       u = chunk_alloca(prf->get_block_size(prf));
-       if (!prf->get_bytes(prf, seed, u.ptr))
-       {
-               return FALSE;
-       }
-       memcpy(block.ptr, u.ptr, block.len);
-
-       for (i = 1; i < iterations; i++)
-       {
-               if (!prf->get_bytes(prf, u, u.ptr))
-               {
-                       return FALSE;
-               }
-               memxor(block.ptr, u.ptr, block.len);
-       }
-       return TRUE;
-}
-
-/**
- * PBKDF2 key derivation function
- */
-static bool pbkdf2(prf_t *prf, chunk_t password, chunk_t salt,
-                                  u_int64_t iterations, chunk_t key)
-{
-       chunk_t keymat, block, seed;
-       size_t blocks;
-       u_int32_t i = 0, *ni;
-
-       if (!prf->set_key(prf, password))
-       {
-               return FALSE;
-       }
-
-       block.len = prf->get_block_size(prf);
-       blocks = (key.len - 1) / block.len + 1;
-       keymat = chunk_alloca(blocks * block.len);
-
-       seed = chunk_cata("cc", salt, chunk_from_thing(i));
-       ni = (u_int32_t*)(seed.ptr + salt.len);
-
-       for (; i < blocks; i++)
-       {
-               *ni = htonl(i + 1);
-               block.ptr = keymat.ptr + (i * block.len);
-               if (!pbkdf2_f(block, prf, seed, iterations))
-               {
-                       return FALSE;
-               }
-       }
 
-       memcpy(key.ptr, keymat.ptr, key.len);
-
-       return TRUE;
-}
-
-/**
- * Decrypt an encrypted PKCS#8 encoded private key according to PBES2
- */
-static private_key_t *decrypt_private_key_pbes2(chunk_t blob,
-                                                       encryption_algorithm_t encr, size_t key_len,
-                                                       chunk_t iv, pseudo_random_function_t prf_func,
-                                                       chunk_t salt, u_int64_t iterations)
-{
-       private_key_t *private_key;
-       prf_t *prf;
-       chunk_t key;
-
-       prf = lib->crypto->create_prf(lib->crypto, prf_func);
-       if (!prf)
-       {
-               DBG1(DBG_ASN, "  %N prf algorithm not available",
-                        pseudo_random_function_names, prf_func);
-               return NULL;
-       }
-
-       key = chunk_alloca(key_len);
-
-       private_key = decrypt_private_key(blob, encr, key_len, (kdf_t)pbkdf2, prf,
-                                                                         salt, iterations, key, key, iv);
-
-       prf->destroy(prf);
-       return private_key;
-}
-
-/**
- * PBKDF1 key derivation function
- */
-static bool pbkdf1(hasher_t *hasher, chunk_t password, chunk_t salt,
-                                  u_int64_t iterations, chunk_t key)
-{
-       chunk_t hash;
-       u_int64_t i;
-
-       hash = chunk_alloca(hasher->get_hash_size(hasher));
-       if (!hasher->get_hash(hasher, password, NULL) ||
-               !hasher->get_hash(hasher, salt, hash.ptr))
-       {
-               return FALSE;
-       }
-
-       for (i = 1; i < iterations; i++)
-       {
-               if (!hasher->get_hash(hasher, hash, hash.ptr))
-               {
-                       return FALSE;
-               }
-       }
-
-       memcpy(key.ptr, hash.ptr, key.len);
-
-       return TRUE;
-}
-
-/**
- * Decrypt an encrypted PKCS#8 encoded private key according to PBES1
- */
-static private_key_t *decrypt_private_key_pbes1(chunk_t blob,
-                                                       encryption_algorithm_t encr, size_t key_len,
-                                                       hash_algorithm_t hash, chunk_t salt,
-                                                       u_int64_t iterations)
-{
-       private_key_t *private_key = NULL;
-       hasher_t *hasher = NULL;
-       chunk_t keymat, key, iv;
-
-       hasher = lib->crypto->create_hasher(lib->crypto, hash);
-       if (!hasher)
-       {
-               DBG1(DBG_ASN, "  %N hash algorithm not available",
-                        hash_algorithm_names, hash);
-               goto end;
-       }
-       if (hasher->get_hash_size(hasher) < key_len)
-       {
-               goto end;
-       }
-
-       keymat = chunk_alloca(key_len * 2);
-       key.len = key_len;
-       key.ptr = keymat.ptr;
-       iv.len = key_len;
-       iv.ptr = keymat.ptr + key_len;
-
-       private_key = decrypt_private_key(blob, encr, key_len, (kdf_t)pbkdf1,
-                                                                         hasher, salt, iterations, keymat,
-                                                                         key, iv);
-
-end:
-       DESTROY_IF(hasher);
        return private_key;
 }
 
 /**
- * Parse an ASN1_INTEGER to a u_int64_t.
- */
-static u_int64_t parse_asn1_integer_uint64(chunk_t blob)
-{
-       u_int64_t val = 0;
-       int i;
-
-       for (i = 0; i < blob.len; i++)
-       {       /* if it is longer than 8 bytes, we just use the 8 LSBs */
-               val <<= 8;
-               val |= (u_int64_t)blob.ptr[i];
-       }
-       return val;
-}
-
-/**
- * ASN.1 definition of a PBKDF2-params structure
- * The salt is actually a CHOICE and could be an AlgorithmIdentifier from
- * PBKDF2-SaltSources (but as per RFC 2898 that's for future versions).
- */
-static const asn1Object_t pbkdf2ParamsObjects[] = {
-       { 0, "PBKDF2-params",   ASN1_SEQUENCE,          ASN1_NONE                       }, /* 0 */
-       { 1,   "salt",                  ASN1_OCTET_STRING,      ASN1_BODY                       }, /* 1 */
-       { 1,   "iterationCount",ASN1_INTEGER,           ASN1_BODY                       }, /* 2 */
-       { 1,   "keyLength",             ASN1_INTEGER,           ASN1_OPT|ASN1_BODY      }, /* 3 */
-       { 1,   "end opt",               ASN1_EOC,                       ASN1_END                        }, /* 4 */
-       { 1,   "prf",                   ASN1_EOC,                       ASN1_DEF|ASN1_RAW       }, /* 5 */
-       { 0, "exit",                    ASN1_EOC,                       ASN1_EXIT                       }
-};
-#define PBKDF2_SALT                                    1
-#define PBKDF2_ITERATION_COUNT         2
-#define PBKDF2_KEY_LENGTH                      3
-#define PBKDF2_PRF                                     5
-
-/**
- * Parse a PBKDF2-params structure
- */
-static void parse_pbkdf2_params(chunk_t blob, chunk_t *salt,
-                                                               u_int64_t *iterations, size_t *key_len,
-                                                               pseudo_random_function_t *prf)
-{
-       asn1_parser_t *parser;
-       chunk_t object;
-       int objectID;
-
-       parser = asn1_parser_create(pbkdf2ParamsObjects, blob);
-
-       *key_len = 0; /* key_len is optional */
-
-       while (parser->iterate(parser, &objectID, &object))
-       {
-               switch (objectID)
-               {
-                       case PBKDF2_SALT:
-                       {
-                               *salt = object;
-                               break;
-                       }
-                       case PBKDF2_ITERATION_COUNT:
-                       {
-                               *iterations = parse_asn1_integer_uint64(object);
-                               break;
-                       }
-                       case PBKDF2_KEY_LENGTH:
-                       {
-                               *key_len = (size_t)parse_asn1_integer_uint64(object);
-                               break;
-                       }
-                       case PBKDF2_PRF:
-                       {       /* defaults to id-hmacWithSHA1 */
-                               *prf = PRF_HMAC_SHA1;
-                               break;
-                       }
-               }
-       }
-
-       parser->destroy(parser);
-}
-
-/**
- * ASN.1 definition of a PBES2-params structure
- */
-static const asn1Object_t pbes2ParamsObjects[] = {
-       { 0, "PBES2-params",            ASN1_SEQUENCE,          ASN1_NONE       }, /* 0 */
-       { 1,   "keyDerivationFunc",     ASN1_EOC,                       ASN1_RAW        }, /* 1 */
-       { 1,   "encryptionScheme",      ASN1_EOC,                       ASN1_RAW        }, /* 2 */
-       { 0, "exit",                            ASN1_EOC,                       ASN1_EXIT       }
-};
-#define PBES2PARAMS_KEY_DERIVATION_FUNC                1
-#define PBES2PARAMS_ENCRYPTION_SCHEME          2
-
-/**
- * Parse a PBES2-params structure
- */
-static void parse_pbes2_params(chunk_t blob, chunk_t *salt,
-                                                          u_int64_t *iterations, size_t *key_len,
-                                                          pseudo_random_function_t *prf,
-                                                          encryption_algorithm_t *encr, chunk_t *iv)
-{
-       asn1_parser_t *parser;
-       chunk_t object, params;
-       int objectID;
-
-       parser = asn1_parser_create(pbes2ParamsObjects, blob);
-
-       while (parser->iterate(parser, &objectID, &object))
-       {
-               switch (objectID)
-               {
-                       case PBES2PARAMS_KEY_DERIVATION_FUNC:
-                       {
-                               int oid = asn1_parse_algorithmIdentifier(object,
-                                                                       parser->get_level(parser) + 1, &params);
-                               if (oid != OID_PBKDF2)
-                               {       /* unsupported key derivation function */
-                                       goto end;
-                               }
-                               parse_pbkdf2_params(params, salt, iterations, key_len, prf);
-                               break;
-                       }
-                       case PBES2PARAMS_ENCRYPTION_SCHEME:
-                       {
-                               int oid = asn1_parse_algorithmIdentifier(object,
-                                                                       parser->get_level(parser) + 1, &params);
-                               if (oid != OID_3DES_EDE_CBC)
-                               {       /* unsupported encryption scheme */
-                                       goto end;
-                               }
-                               if (*key_len <= 0)
-                               {       /* default key len for DES-EDE3-CBC-Pad */
-                                       *key_len = 24;
-                               }
-                               if (!asn1_parse_simple_object(&params, ASN1_OCTET_STRING,
-                                                                       parser->get_level(parser) + 1, "IV"))
-                               {
-                                       goto end;
-                               }
-                               *encr = ENCR_3DES;
-                               *iv = params;
-                               break;
-                       }
-               }
-       }
-
-end:
-       parser->destroy(parser);
-}
-
-/**
- * ASN.1 definition of a PBEParameter structure
- */
-static const asn1Object_t pbeParameterObjects[] = {
-       { 0, "PBEParameter",            ASN1_SEQUENCE,          ASN1_NONE       }, /* 0 */
-       { 1,   "salt",                          ASN1_OCTET_STRING,      ASN1_BODY       }, /* 1 */
-       { 1,   "iterationCount",        ASN1_INTEGER,           ASN1_BODY       }, /* 2 */
-       { 0, "exit",                            ASN1_EOC,                       ASN1_EXIT       }
-};
-#define PBEPARAM_SALT                                  1
-#define PBEPARAM_ITERATION_COUNT               2
-
-/**
- * Parse a PBEParameter structure
- */
-static void parse_pbe_parameters(chunk_t blob, chunk_t *salt,
-                                                                u_int64_t *iterations)
-{
-       asn1_parser_t *parser;
-       chunk_t object;
-       int objectID;
-
-       parser = asn1_parser_create(pbeParameterObjects, blob);
-
-       while (parser->iterate(parser, &objectID, &object))
-       {
-               switch (objectID)
-               {
-                       case PBEPARAM_SALT:
-                       {
-                               *salt = object;
-                               break;
-                       }
-                       case PBEPARAM_ITERATION_COUNT:
-                       {
-                               *iterations = parse_asn1_integer_uint64(object);
-                               break;
-                       }
-               }
-       }
-
-       parser->destroy(parser);
-}
-
-/**
  * ASN.1 definition of an encryptedPrivateKeyInfo structure
  */
 static const asn1Object_t encryptedPKIObjects[] = {
@@ -563,14 +153,10 @@ static const asn1Object_t encryptedPKIObjects[] = {
 static private_key_t *parse_encrypted_private_key(chunk_t blob)
 {
        asn1_parser_t *parser;
-       chunk_t object, params, salt = chunk_empty, iv = chunk_empty;
-       u_int64_t iterations = 0;
+       chunk_t object;
        int objectID;
-       encryption_algorithm_t encr = ENCR_UNDEFINED;
-       hash_algorithm_t hash = HASH_UNKNOWN;
-       pseudo_random_function_t prf = PRF_UNDEFINED;
        private_key_t *key = NULL;
-       size_t key_len = 8;
+       pkcs5_t *pkcs5 = NULL;
 
        parser = asn1_parser_create(encryptedPKIObjects, blob);
 
@@ -580,49 +166,24 @@ static private_key_t *parse_encrypted_private_key(chunk_t blob)
                {
                        case EPKINFO_ENCRYPTION_ALGORITHM:
                        {
-                               int oid = asn1_parse_algorithmIdentifier(object,
-                                                                       parser->get_level(parser) + 1, &params);
-
-                               switch (oid)
+                               pkcs5 = pkcs5_from_algorithmIdentifier(object,
+                                                                                               parser->get_level(parser) + 1);
+                               if (!pkcs5)
                                {
-                                       case OID_PBE_MD5_DES_CBC:
-                                               encr = ENCR_DES;
-                                               hash = HASH_MD5;
-                                               parse_pbe_parameters(params, &salt, &iterations);
-                                               break;
-                                       case OID_PBE_SHA1_DES_CBC:
-                                               encr = ENCR_DES;
-                                               hash = HASH_SHA1;
-                                               parse_pbe_parameters(params, &salt, &iterations);
-                                               break;
-                                       case OID_PBES2:
-                                               parse_pbes2_params(params, &salt, &iterations,
-                                                                                  &key_len, &prf, &encr, &iv);
-                                               break;
-                                       default:
-                                               /* encryption scheme not supported */
-                                               goto end;
+                                       goto end;
                                }
                                break;
                        }
                        case EPKINFO_ENCRYPTED_DATA:
                        {
-                               if (prf != PRF_UNDEFINED)
-                               {
-                                       key = decrypt_private_key_pbes2(object, encr, key_len, iv,
-                                                                                                       prf, salt, iterations);
-                               }
-                               else
-                               {
-                                       key = decrypt_private_key_pbes1(object, encr, key_len, hash,
-                                                                                                       salt, iterations);
-                               }
+                               key = decrypt_private_key(pkcs5, object);
                                break;
                        }
                }
        }
 
 end:
+       DESTROY_IF(pkcs5);
        parser->destroy(parser);
        return key;
 }