Imported Upstream version 4.6.4

1 files changed, 632 insertions, 0 deletions

diff --git a/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c b/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
new file mode 100644
index 000000000..346240ae1
--- /dev/null
+++ b/src/libstrongswan/plugins/pkcs8/pkcs8_builder.c
@@ -0,0 +1,632 @@
+/*
+ * Copyright (C) 2012 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 "pkcs8_builder.h"
+
+#include <debug.h>
+#include <asn1/oid.h>
+#include <asn1/asn1.h>
+#include <asn1/asn1_parser.h>
+#include <credentials/keys/private_key.h>
+
+/**
+ * ASN.1 definition of a privateKeyInfo structure
+ */
+static const asn1Object_t pkinfoObjects[] = {
+	{ 0, "privateKeyInfo",			ASN1_SEQUENCE,		ASN1_NONE	}, /* 0 */
+	{ 1,   "version",				ASN1_INTEGER,		ASN1_BODY	}, /* 1 */
+	{ 1,   "privateKeyAlgorithm",	ASN1_EOC,			ASN1_RAW	}, /* 2 */
+	{ 1,   "privateKey",			ASN1_OCTET_STRING,	ASN1_BODY	}, /* 3 */
+	{ 1,   "attributes",			ASN1_CONTEXT_C_0,	ASN1_OPT	}, /* 4 */
+	{ 1,   "end opt",				ASN1_EOC,			ASN1_END	}, /* 5 */
+	{ 0, "exit",					ASN1_EOC,			ASN1_EXIT	}
+};
+#define PKINFO_PRIVATE_KEY_ALGORITHM	2
+#define PKINFO_PRIVATE_KEY				3
+
+/**
+ * Load a generic private key from an ASN.1 encoded blob
+ */
+static private_key_t *parse_private_key(chunk_t blob)
+{
+	asn1_parser_t *parser;
+	chunk_t object, params = chunk_empty;
+	int objectID;
+	private_key_t *key = NULL;
+	key_type_t type = KEY_ANY;
+
+	parser = asn1_parser_create(pkinfoObjects, blob);
+	parser->set_flags(parser, FALSE, TRUE);
+
+	while (parser->iterate(parser, &objectID, &object))
+	{
+		switch (objectID)
+		{
+			case PKINFO_PRIVATE_KEY_ALGORITHM:
+			{
+				int oid = asn1_parse_algorithmIdentifier(object,
+									parser->get_level(parser) + 1, &params);
+
+				switch (oid)
+				{
+					case OID_RSA_ENCRYPTION:
+						type = KEY_RSA;
+						break;
+					case OID_EC_PUBLICKEY:
+						type = KEY_ECDSA;
+						break;
+					default:
+						/* key type not supported */
+						goto end;
+				}
+				break;
+			}
+			case PKINFO_PRIVATE_KEY:
+			{
+				DBG2(DBG_ASN, "-- > --");
+				if (params.ptr)
+				{
+					key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
+											 type, BUILD_BLOB_ALGID_PARAMS,
+											 params, BUILD_BLOB_ASN1_DER,
+											 object, BUILD_END);
+				}
+				else
+				{
+					key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
+											 type, BUILD_BLOB_ASN1_DER, object,
+											 BUILD_END);
+				}
+				DBG2(DBG_ASN, "-- < --");
+				break;
+			}
+		}
+	}
+
+end:
+	parser->destroy(parser);
+	return key;
+}
+
+/**
+ * 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 void (*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.
+ */
+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)
+{
+	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;
+
+		kdf(generator, shared->get_key(shared), salt, iterations, keymat);
+
+		crypter->set_key(crypter, key);
+		crypter->decrypt(crypter, blob, iv, &decrypted);
+		if (verify_padding(&decrypted))
+		{
+			private_key = parse_private_key(decrypted);
+			if (private_key)
+			{
+				chunk_clear(&decrypted);
+				break;
+			}
+		}
+		chunk_free(&decrypted);
+	}
+	enumerator->destroy(enumerator);
+	crypter->destroy(crypter);
+
+	return private_key;
+}
+
+/**
+ * Function F of PBKDF2
+ */
+static void 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));
+	prf->get_bytes(prf, seed, u.ptr);
+	memcpy(block.ptr, u.ptr, block.len);
+
+	for (i = 1; i < iterations; i++)
+	{
+		prf->get_bytes(prf, u, u.ptr);
+		memxor(block.ptr, u.ptr, block.len);
+	}
+}
+
+/**
+ * PBKDF2 key derivation function
+ */
+static void 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;
+
+	prf->set_key(prf, password);
+
+	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);
+		pbkdf2_f(block, prf, seed, iterations);
+	}
+
+	memcpy(key.ptr, keymat.ptr, key.len);
+}
+
+/**
+ * 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 void 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));
+	hasher->get_hash(hasher, password, NULL);
+	hasher->get_hash(hasher, salt, hash.ptr);
+
+	for (i = 1; i < iterations; i++)
+	{
+		hasher->get_hash(hasher, hash, hash.ptr);
+	}
+
+	memcpy(key.ptr, hash.ptr, key.len);
+}
+
+/**
+ * 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[] = {
+	{ 0, "encryptedPrivateKeyInfo",	ASN1_SEQUENCE,		ASN1_NONE	}, /* 0 */
+	{ 1,   "encryptionAlgorithm",	ASN1_EOC,			ASN1_RAW	}, /* 1 */
+	{ 1,   "encryptedData",			ASN1_OCTET_STRING,	ASN1_BODY	}, /* 2 */
+	{ 0, "exit",					ASN1_EOC,			ASN1_EXIT	}
+};
+#define EPKINFO_ENCRYPTION_ALGORITHM	1
+#define EPKINFO_ENCRYPTED_DATA			2
+
+/**
+ * Load an encrypted private key from an ASN.1 encoded blob
+ * Schemes per PKCS#5 (RFC 2898)
+ */
+static private_key_t *parse_encrypted_private_key(chunk_t blob)
+{
+	asn1_parser_t *parser;
+	chunk_t object, params, salt, iv;
+	u_int64_t iterations = 0;
+	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;
+
+	parser = asn1_parser_create(encryptedPKIObjects, blob);
+
+	while (parser->iterate(parser, &objectID, &object))
+	{
+		switch (objectID)
+		{
+			case EPKINFO_ENCRYPTION_ALGORITHM:
+			{
+				int oid = asn1_parse_algorithmIdentifier(object,
+									parser->get_level(parser) + 1, &params);
+
+				switch (oid)
+				{
+					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;
+				}
+				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);
+				}
+				break;
+			}
+		}
+	}
+
+end:
+	parser->destroy(parser);
+	return key;
+}
+
+/**
+ * See header.
+ */
+private_key_t *pkcs8_private_key_load(key_type_t type, va_list args)
+{
+	chunk_t blob = chunk_empty;
+	private_key_t *key;
+
+	while (TRUE)
+	{
+		switch (va_arg(args, builder_part_t))
+		{
+			case BUILD_BLOB_ASN1_DER:
+				blob = va_arg(args, chunk_t);
+				continue;
+			case BUILD_END:
+				break;
+			default:
+				return NULL;
+		}
+		break;
+	}
+	/* we don't know whether it is encrypted or not, try both ways */
+	key = parse_encrypted_private_key(blob);
+	if (!key)
+	{
+		key = parse_private_key(blob);
+	}
+	return key;
+}
+