Extract PKCS#5 handling from pkcs8 plugin to separate helper class

5 files changed, 710 insertions, 458 deletions

diff --git a/src/libstrongswan/Android.mk b/src/libstrongswan/Android.mk
index a46b0d9a1..289697a46 100644
--- a/src/libstrongswan/Android.mk
+++ b/src/libstrongswan/Android.mk
@@ -8,7 +8,7 @@ asn1/asn1.c asn1/asn1_parser.c asn1/oid.c bio/bio_reader.c bio/bio_writer.c \
 collections/blocking_queue.c collections/enumerator.c collections/hashtable.c \
 collections/linked_list.c crypto/crypters/crypter.c crypto/hashers/hasher.c \
 crypto/proposal/proposal_keywords.c crypto/proposal/proposal_keywords_static.c \
-crypto/prfs/prf.c crypto/prfs/mac_prf.c \
+crypto/prfs/prf.c crypto/prfs/mac_prf.c crypto/pkcs5.c \
 crypto/rngs/rng.c crypto/prf_plus.c crypto/signers/signer.c \
 crypto/signers/mac_signer.c crypto/crypto_factory.c crypto/crypto_tester.c \
 crypto/diffie_hellman.c crypto/aead.c crypto/transform.c \
diff --git a/src/libstrongswan/Makefile.am b/src/libstrongswan/Makefile.am
index b5a4b9bab..5968a3b3f 100644
--- a/src/libstrongswan/Makefile.am
+++ b/src/libstrongswan/Makefile.am
@@ -6,7 +6,7 @@ asn1/asn1.c asn1/asn1_parser.c asn1/oid.c bio/bio_reader.c bio/bio_writer.c \
 collections/blocking_queue.c collections/enumerator.c collections/hashtable.c \
 collections/linked_list.c crypto/crypters/crypter.c crypto/hashers/hasher.c \
 crypto/proposal/proposal_keywords.c crypto/proposal/proposal_keywords_static.c \
-crypto/prfs/prf.c crypto/prfs/mac_prf.c \
+crypto/prfs/prf.c crypto/prfs/mac_prf.c crypto/pkcs5.c \
 crypto/rngs/rng.c crypto/prf_plus.c crypto/signers/signer.c \
 crypto/signers/mac_signer.c crypto/crypto_factory.c crypto/crypto_tester.c \
 crypto/diffie_hellman.c crypto/aead.c crypto/transform.c \
@@ -45,7 +45,7 @@ crypto/proposal/proposal_keywords.h crypto/proposal/proposal_keywords_static.h \
 crypto/prfs/prf.h crypto/prfs/mac_prf.h crypto/rngs/rng.h crypto/nonce_gen.h \
 crypto/prf_plus.h crypto/signers/signer.h crypto/signers/mac_signer.h \
 crypto/crypto_factory.h crypto/crypto_tester.h crypto/diffie_hellman.h \
-crypto/aead.h crypto/transform.h \
+crypto/aead.h crypto/transform.h crypto/pkcs5.h \
 credentials/credential_factory.h credentials/builder.h \
 credentials/cred_encoding.h credentials/keys/private_key.h \
 credentials/keys/public_key.h credentials/keys/shared_key.h \
diff --git a/src/libstrongswan/crypto/pkcs5.c b/src/libstrongswan/crypto/pkcs5.c
new file mode 100644
index 000000000..76a67fc4a
--- /dev/null
+++ b/src/libstrongswan/crypto/pkcs5.c
@@ -0,0 +1,630 @@
+/*
+ * Copyright (C) 2012-2013 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "pkcs5.h"
+
+#include <utils/debug.h>
+#include <asn1/oid.h>
+#include <asn1/asn1.h>
+#include <asn1/asn1_parser.h>
+
+typedef struct private_pkcs5_t private_pkcs5_t;
+
+/**
+ * Private data of a pkcs5_t object
+ */
+struct private_pkcs5_t {
+
+	/**
+	 * Implements pkcs5_t.
+	 */
+	pkcs5_t public;
+
+	/**
+	 * Salt used during encryption
+	 */
+	chunk_t salt;
+
+	/**
+	 * Iterations for key derivation
+	 */
+	u_int64_t iterations;
+
+	/**
+	 * Encryption algorithm
+	 */
+	encryption_algorithm_t encr;
+
+	/**
+	 * Encryption key length
+	 */
+	size_t keylen;
+
+	/**
+	 * Crypter
+	 */
+	crypter_t *crypter;
+
+
+	/**
+	 * The encryption scheme
+	 */
+	enum {
+		PKCS5_SCHEME_PBES1,
+		PKCS5_SCHEME_PBES2,
+	} scheme;
+
+	/**
+	 * Data used for individual schemes
+	 */
+	union {
+		struct {
+			/**
+			 * Hash algorithm
+			 */
+			hash_algorithm_t hash;
+
+			/**
+			 * Hasher
+			 */
+			hasher_t *hasher;
+
+		} pbes1;
+		struct {
+			/**
+			 * PRF algorithm
+			 */
+			pseudo_random_function_t prf_alg;
+
+			/**
+			 * PRF
+			 */
+			prf_t * prf;
+
+			/**
+			 * IV
+			 */
+			chunk_t iv;
+
+		} pbes2;
+	} data;
+};
+
+/**
+ * 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)(private_pkcs5_t *this, chunk_t password, chunk_t key);
+
+/**
+ * Try to decrypt the given data with the given password 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.
+ */
+static bool decrypt_generic(private_pkcs5_t *this, chunk_t password,
+							chunk_t data, chunk_t *decrypted, kdf_t kdf,
+							chunk_t keymat, chunk_t key, chunk_t iv)
+{
+	if (!kdf(this, password, keymat))
+	{
+		return FALSE;
+	}
+	if (!this->crypter->set_key(this->crypter, key) ||
+		!this->crypter->decrypt(this->crypter, data, iv, decrypted))
+	{
+		memwipe(keymat.ptr, keymat.len);
+		return FALSE;
+	}
+	memwipe(keymat.ptr, keymat.len);
+	if (verify_padding(decrypted))
+	{
+		return TRUE;
+	}
+	chunk_free(decrypted);
+	return FALSE;
+}
+
+/**
+ * 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 for PBES2, key must be allocated
+ */
+static bool pbkdf2(private_pkcs5_t *this, chunk_t password, chunk_t key)
+{
+	prf_t *prf;
+	chunk_t keymat, block, seed;
+	size_t blocks;
+	u_int32_t i = 0;
+
+	prf = this->data.pbes2.prf;
+
+	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", this->salt, chunk_from_thing(i));
+
+	for (; i < blocks; i++)
+	{
+		htoun32(seed.ptr + this->salt.len, i + 1);
+		block.ptr = keymat.ptr + (i * block.len);
+		if (!pbkdf2_f(block, prf, seed, this->iterations))
+		{
+			return FALSE;
+		}
+	}
+	memcpy(key.ptr, keymat.ptr, key.len);
+	return TRUE;
+}
+
+/**
+ * PBKDF1 key derivation function for PBES1, key must be allocated
+ */
+static bool pbkdf1(private_pkcs5_t *this, chunk_t password, chunk_t key)
+{
+	hasher_t *hasher;
+	chunk_t hash;
+	u_int64_t i;
+
+	hasher = this->data.pbes1.hasher;
+
+	hash = chunk_alloca(hasher->get_hash_size(hasher));
+	if (!hasher->get_hash(hasher, password, NULL) ||
+		!hasher->get_hash(hasher, this->salt, hash.ptr))
+	{
+		return FALSE;
+	}
+
+	for (i = 1; i < this->iterations; i++)
+	{
+		if (!hasher->get_hash(hasher, hash, hash.ptr))
+		{
+			return FALSE;
+		}
+	}
+	memcpy(key.ptr, hash.ptr, key.len);
+	return TRUE;
+}
+
+static bool ensure_crypto_primitives(private_pkcs5_t *this, chunk_t data)
+{
+	if (!this->crypter)
+	{
+		this->crypter = lib->crypto->create_crypter(lib->crypto, this->encr,
+													this->keylen);
+		if (!this->crypter)
+		{
+			DBG1(DBG_ASN, "  %N encryption algorithm not available",
+				 encryption_algorithm_names, this->encr);
+			return FALSE;
+		}
+	}
+	if (data.len % this->crypter->get_block_size(this->crypter))
+	{
+		DBG1(DBG_ASN, "  data size is not a multiple of block size");
+		return FALSE;
+	}
+	switch (this->scheme)
+	{
+		case PKCS5_SCHEME_PBES1:
+		{
+			if (!this->data.pbes1.hasher)
+			{
+				hasher_t *hasher;
+
+				hasher = lib->crypto->create_hasher(lib->crypto,
+													this->data.pbes1.hash);
+				if (!hasher)
+				{
+					DBG1(DBG_ASN, "  %N hash algorithm not available",
+						 hash_algorithm_names, this->data.pbes1.hash);
+					return  FALSE;
+				}
+				if (hasher->get_hash_size(hasher) < this->keylen)
+				{
+					hasher->destroy(hasher);
+					return FALSE;
+				}
+				this->data.pbes1.hasher = hasher;
+			}
+		}
+		case PKCS5_SCHEME_PBES2:
+		{
+			if (!this->data.pbes2.prf)
+			{
+				prf_t *prf;
+
+				prf = lib->crypto->create_prf(lib->crypto,
+											  this->data.pbes2.prf_alg);
+				if (!prf)
+				{
+					DBG1(DBG_ASN, "  %N prf algorithm not available",
+						 pseudo_random_function_names,
+						 this->data.pbes2.prf_alg);
+					return FALSE;
+				}
+				this->data.pbes2.prf = prf;
+			}
+		}
+	}
+	return TRUE;
+}
+
+METHOD(pkcs5_t, decrypt, bool,
+	private_pkcs5_t *this, chunk_t password, chunk_t data, chunk_t *decrypted)
+{
+	chunk_t keymat, key, iv;
+	kdf_t kdf;
+
+	if (!ensure_crypto_primitives(this, data) || !decrypted)
+	{
+		return FALSE;
+	}
+	switch (this->scheme)
+	{
+		case PKCS5_SCHEME_PBES1:
+			kdf = pbkdf1;
+			keymat = chunk_alloca(this->keylen * 2);
+			key = chunk_create(keymat.ptr, this->keylen);
+			iv = chunk_create(keymat.ptr + this->keylen, this->keylen);
+			break;
+		case PKCS5_SCHEME_PBES2:
+			kdf = pbkdf2;
+			keymat = chunk_alloca(this->keylen);
+			key = keymat;
+			iv = this->data.pbes2.iv;
+			break;
+		default:
+			return FALSE;
+	}
+	return decrypt_generic(this, password, data, decrypted, kdf,
+						   keymat, key, iv);
+}
+
+/**
+ * Converts an ASN.1 INTEGER object to an u_int64_t. If the INTEGER is longer
+ * than 8 bytes only the 8 LSBs are returned.
+ *
+ * @param blob		body of an ASN.1 coded integer object
+ * @return			converted integer
+ */
+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 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 bool parse_pbes1_params(private_pkcs5_t *this, chunk_t blob, int level0)
+{
+	asn1_parser_t *parser;
+	chunk_t object;
+	int objectID;
+	bool success;
+
+	parser = asn1_parser_create(pbeParameterObjects, blob);
+	parser->set_top_level(parser, level0);
+
+	while (parser->iterate(parser, &objectID, &object))
+	{
+		switch (objectID)
+		{
+			case PBEPARAM_SALT:
+			{
+				this->salt = chunk_clone(object);
+				break;
+			}
+			case PBEPARAM_ITERATION_COUNT:
+			{
+				this->iterations = parse_asn1_integer_uint64(object);
+				break;
+			}
+		}
+	}
+	success = parser->success(parser);
+	parser->destroy(parser);
+	return success;
+}
+
+/**
+ * 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_KEYLENGTH			3
+#define PBKDF2_PRF					5
+
+/**
+ * Parse a PBKDF2-params structure
+ */
+static bool parse_pbkdf2_params(private_pkcs5_t *this, chunk_t blob, int level0)
+{
+	asn1_parser_t *parser;
+	chunk_t object;
+	int objectID;
+	bool success;
+
+	parser = asn1_parser_create(pbkdf2ParamsObjects, blob);
+	parser->set_top_level(parser, level0);
+
+ 	/* keylen is optional */
+	this->keylen = 0;
+
+	while (parser->iterate(parser, &objectID, &object))
+	{
+		switch (objectID)
+		{
+			case PBKDF2_SALT:
+			{
+				this->salt = chunk_clone(object);
+				break;
+			}
+			case PBKDF2_ITERATION_COUNT:
+			{
+				this->iterations = parse_asn1_integer_uint64(object);
+				break;
+			}
+			case PBKDF2_KEYLENGTH:
+			{
+				this->keylen = (size_t)parse_asn1_integer_uint64(object);
+				break;
+			}
+			case PBKDF2_PRF:
+			{	/* defaults to id-hmacWithSHA1, no other is currently defined */
+				this->data.pbes2.prf_alg = PRF_HMAC_SHA1;
+				break;
+			}
+		}
+	}
+	success = parser->success(parser);
+	parser->destroy(parser);
+	return success;
+}
+
+/**
+ * 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 bool parse_pbes2_params(private_pkcs5_t *this, chunk_t blob, int level0)
+{
+	asn1_parser_t *parser;
+	chunk_t object, params;
+	int objectID;
+	bool success = FALSE;
+
+	parser = asn1_parser_create(pbes2ParamsObjects, blob);
+	parser->set_top_level(parser, level0);
+
+	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;
+				}
+				if (!parse_pbkdf2_params(this, params,
+										 parser->get_level(parser) + 1))
+				{
+					goto end;
+				}
+				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 (this->keylen <= 0)
+				{	/* default key length for DES-EDE3-CBC-Pad */
+					this->keylen = 24;
+				}
+				if (!asn1_parse_simple_object(&params, ASN1_OCTET_STRING,
+									parser->get_level(parser) + 1, "IV"))
+				{
+					goto end;
+				}
+				this->encr = ENCR_3DES;
+				this->data.pbes2.iv = chunk_clone(params);
+				break;
+			}
+		}
+	}
+	success = parser->success(parser);
+end:
+	parser->destroy(parser);
+	return success;
+}
+
+METHOD(pkcs5_t, destroy, void,
+	private_pkcs5_t *this)
+{
+	DESTROY_IF(this->crypter);
+	chunk_free(&this->salt);
+	switch (this->scheme)
+	{
+		case PKCS5_SCHEME_PBES1:
+			DESTROY_IF(this->data.pbes1.hasher);
+			break;
+		case PKCS5_SCHEME_PBES2:
+			DESTROY_IF(this->data.pbes2.prf);
+			chunk_free(&this->data.pbes2.iv);
+			break;
+	}
+	free(this);
+}
+
+/*
+ * Described in header
+ */
+pkcs5_t *pkcs5_from_algorithmIdentifier(chunk_t blob, int level0)
+{
+	private_pkcs5_t *this;
+	chunk_t params;
+	int oid;
+
+	INIT(this,
+		.public = {
+			.decrypt = _decrypt,
+			.destroy = _destroy,
+		},
+		.scheme = PKCS5_SCHEME_PBES1,
+		.keylen = 8,
+	);
+
+	oid = asn1_parse_algorithmIdentifier(blob, level0, &params);
+
+	switch (oid)
+	{
+		case OID_PBE_MD5_DES_CBC:
+			this->encr = ENCR_DES;
+			this->data.pbes1.hash = HASH_MD5;
+			break;
+		case OID_PBE_SHA1_DES_CBC:
+			this->encr = ENCR_DES;
+			this->data.pbes1.hash = HASH_SHA1;
+			break;
+		case OID_PBES2:
+			this->scheme = PKCS5_SCHEME_PBES2;
+			break;
+		default:
+			/* encryption scheme not supported */
+			goto failure;
+	}
+
+	switch (this->scheme)
+	{
+		case PKCS5_SCHEME_PBES1:
+			if (!parse_pbes1_params(this, params, level0))
+			{
+				goto failure;
+			}
+			break;
+		case PKCS5_SCHEME_PBES2:
+			if (!parse_pbes2_params(this, params, level0))
+			{
+				goto failure;
+			}
+			break;
+	}
+	return &this->public;
+
+failure:
+	destroy(this);
+	return NULL;
+}
diff --git a/src/libstrongswan/crypto/pkcs5.h b/src/libstrongswan/crypto/pkcs5.h
new file mode 100644
index 000000000..b16d3736e
--- /dev/null
+++ b/src/libstrongswan/crypto/pkcs5.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2013 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup pkcs5 pkcs5
+ * @{ @ingroup crypto
+ */
+
+#ifndef PKCS5_H_
+#define PKCS5_H_
+
+typedef struct pkcs5_t pkcs5_t;
+
+#include <utils/chunk.h>
+
+/**
+ * PKCS#5 helper class
+ */
+struct pkcs5_t {
+
+	/**
+	 * Decrypt the given data using the given password and the scheme derived
+	 * from the initial AlgorithmIdentifier object.
+	 *
+	 * @param password	password used for decryption
+	 * @param data		data to decrypt
+	 * @param decrypted	decrypted data gets allocated
+	 * @return			TRUE on success, FALSE otherwise
+	 */
+	bool (*decrypt)(pkcs5_t *this, chunk_t password, chunk_t data,
+					chunk_t *decrypted) __attribute__((warn_unused_result));
+
+	/**
+	 * Destroy the object and any associated cryptographic primitive.
+	 */
+	void (*destroy)(pkcs5_t *this);
+};
+
+/**
+ * Create a PKCS#5 helper object from an ASN.1 encoded AlgorithmIdentifier
+ * object.
+ *
+ * @param blob			ASN.1 encoded AlgorithmIdentifier
+ * @param level0		ASN.1 parser level
+ * @return				pkcs5_t object, NULL on failure
+ */
+pkcs5_t *pkcs5_from_algorithmIdentifier(chunk_t blob, int level0);
+
+#endif /** PKCS5_H_ @}*/
diff --git a/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c b/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
index 26a3620d7..e93a8361c 100644
--- a/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
+++ b/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
@@ -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;
 }