Move PBKDF2 into crypto backend wrapper.

Implement new KDF bechmark check.
Use internal openssl kdf (and prepare gcrypt one).

lib/crypto_backend/Makefile.am

@@ -4,22 +4,26 @@ noinst_LTLIBRARIES = libcrypto_backend.la
 
 libcrypto_backend_la_CFLAGS = -Wall @CRYPTO_CFLAGS@
 
-libcrypto_backend_la_SOURCES = crypto_backend.h
+libcrypto_backend_la_SOURCES = crypto_backend.h pbkdf_check.c
 
 if CRYPTO_BACKEND_GCRYPT
 libcrypto_backend_la_SOURCES += crypto_gcrypt.c
+libcrypto_backend_la_SOURCES += pbkdf2_generic.c
 endif
 if CRYPTO_BACKEND_OPENSSL
 libcrypto_backend_la_SOURCES += crypto_openssl.c
 endif
 if CRYPTO_BACKEND_NSS
 libcrypto_backend_la_SOURCES += crypto_nss.c
+libcrypto_backend_la_SOURCES += pbkdf2_generic.c
 endif
 if CRYPTO_BACKEND_KERNEL
 libcrypto_backend_la_SOURCES += crypto_kernel.c
+libcrypto_backend_la_SOURCES += pbkdf2_generic.c
 endif
 if CRYPTO_BACKEND_NETTLE
 libcrypto_backend_la_SOURCES += crypto_nettle.c
+libcrypto_backend_la_SOURCES += pbkdf2_generic.c
 endif
 
 INCLUDES = -D_GNU_SOURCE -I$(top_srcdir)/lib

lib/crypto_backend/crypto_backend.h

@@ -20,6 +20,7 @@
 #define _CRYPTO_BACKEND_H
 
 #include <stdint.h>
+#include <string.h>
 #include "config.h"
 
 struct crypt_device;
@@ -52,4 +53,19 @@ int crypt_hmac_destroy(struct crypt_hmac *ctx);
 enum { CRYPT_RND_NORMAL = 0, CRYPT_RND_KEY = 1, CRYPT_RND_SALT = 2 };
 int crypt_backend_rng(char *buffer, size_t length, int quality, int fips);
 
+/* PBKDF*/
+int crypt_pbkdf_check(const char *kdf, const char *hash, uint64_t *iter_secs);
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		unsigned int iterations);
+
+/* internal PBKDF2 implementation */
+int pkcs5_pbkdf2(const char *hash,
+		 const char *P, size_t Plen,
+		 const char *S, size_t Slen,
+		 unsigned int c,
+		 unsigned int dkLen,char *DK);
+
 #endif /* _CRYPTO_BACKEND_H */

lib/crypto_backend/crypto_gcrypt.c

@@ -251,3 +251,44 @@ int crypt_backend_rng(char *buffer, size_t length, int quality, int fips)
 	}
 	return 0;
 }
+
+/* PBKDF */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		unsigned int iterations)
+{
+	if (!kdf || strncmp(kdf, "pbkdf2", 6))
+		return -EINVAL;
+
+	return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
+			    iterations, key_length, key);
+}
+
+#if 0
+/* Until bug in gcrypt related to empty password is fixed,  cannot use this */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		unsigned int iterations)
+{
+	int hash_id = gcry_md_map_name(hash);
+	int kdf_id;
+
+	if (!hash_id)
+		return -EINVAL;
+
+	if (kdf && !strncmp(kdf, "pbkdf2", 6))
+		kdf_id = GCRY_KDF_PBKDF2;
+	else
+		return -EINVAL;
+
+	if (gcry_kdf_derive(password, password_length, kdf_id, hash_id,
+	    salt, salt_length, iterations, key_length, key))
+		return -EINVAL;
+
+	return 0;
+}
+#endif

lib/crypto_backend/crypto_kernel.c

@@ -302,3 +302,17 @@ int crypt_backend_rng(char *buffer, size_t length, int quality, int fips)
 {
 	return -EINVAL;
 }
+
+/* PBKDF */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		unsigned int iterations)
+{
+	if (!kdf || strncmp(kdf, "pbkdf2", 6))
+		return -EINVAL;
+
+	return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
+			    iterations, key_length, key);
+}

lib/crypto_backend/crypto_nettle.c

@@ -274,3 +274,18 @@ int crypt_backend_rng(char *buffer, size_t length, int quality, int fips)
 {
 	return -EINVAL;
 }
+
+/* PBKDF */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		unsigned int iterations)
+{
+	if (!kdf || strncmp(kdf, "pbkdf2", 6))
+		return -EINVAL;
+
+	/* FIXME: switch to internal implementation in Nettle 2.6 */
+	return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
+			    iterations, key_length, key);
+}

lib/crypto_backend/crypto_nss.c

@@ -298,3 +298,17 @@ int crypt_backend_rng(char *buffer, size_t length, int quality, int fips)
 
 	return 0;
 }
+
+/* PBKDF */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		unsigned int iterations)
+{
+	if (!kdf || strncmp(kdf, "pbkdf2", 6))
+		return -EINVAL;
+
+	return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
+			    iterations, key_length, key);
+}

lib/crypto_backend/crypto_openssl.c

@@ -52,7 +52,7 @@ int crypt_backend_init(struct crypt_device *ctx)
 	if (crypto_backend_initialised)
 		return 0;
 
-	OpenSSL_add_all_digests();
+	OpenSSL_add_all_algorithms();
 
 	crypto_backend_initialised = 1;
 	return 0;
@@ -230,3 +230,27 @@ int crypt_backend_rng(char *buffer, size_t length, int quality, int fips)
 
 	return 0;
 }
+
+/* PBKDF */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		unsigned int iterations)
+{
+	const EVP_MD *hash_id;
+
+	if (!kdf || strncmp(kdf, "pbkdf2", 6))
+		return -EINVAL;
+
+	hash_id = EVP_get_digestbyname(hash);
+	if (!hash_id)
+		return -EINVAL;
+
+	if (!PKCS5_PBKDF2_HMAC(password, (int)password_length,
+	    (unsigned char *)salt, (int)salt_length,
+            (int)iterations, hash_id, (int)key_length, (unsigned char *)key))
+		return -EINVAL;
+
+	return 0;
+}

lib/crypto_backend/pbkdf2_generic.c

@@ -0,0 +1,189 @@
+/*
+ * Implementation of Password-Based Cryptography as per PKCS#5
+ * Copyright (C) 2002,2003 Simon Josefsson
+ * Copyright (C) 2004 Free Software Foundation
+ *
+ * cryptsetup related changes
+ * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
+ *
+ * This file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This file 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <errno.h>
+#include <alloca.h>
+#include "crypto_backend.h"
+
+/*
+ * 5.2 PBKDF2
+ *
+ *  PBKDF2 applies a pseudorandom function (see Appendix B.1 for an
+ *  example) to derive keys. The length of the derived key is essentially
+ *  unbounded. (However, the maximum effective search space for the
+ *  derived key may be limited by the structure of the underlying
+ *  pseudorandom function. See Appendix B.1 for further discussion.)
+ *  PBKDF2 is recommended for new applications.
+ *
+ *  PBKDF2 (P, S, c, dkLen)
+ *
+ *  Options:        PRF        underlying pseudorandom function (hLen
+ *                             denotes the length in octets of the
+ *                             pseudorandom function output)
+ *
+ *  Input:          P          password, an octet string (ASCII or UTF-8)
+ *                  S          salt, an octet string
+ *                  c          iteration count, a positive integer
+ *                  dkLen      intended length in octets of the derived
+ *                             key, a positive integer, at most
+ *                             (2^32 - 1) * hLen
+ *
+ *  Output:         DK         derived key, a dkLen-octet string
+ */
+
+#define MAX_PRF_BLOCK_LEN 80
+
+int pkcs5_pbkdf2(const char *hash,
+			const char *P, size_t Plen,
+			const char *S, size_t Slen,
+			unsigned int c, unsigned int dkLen,
+			char *DK)
+{
+	struct crypt_hmac *hmac;
+	char U[MAX_PRF_BLOCK_LEN];
+	char T[MAX_PRF_BLOCK_LEN];
+	int i, k, rc = -EINVAL;
+	unsigned int u, hLen, l, r;
+	size_t tmplen = Slen + 4;
+	char *tmp;
+
+	tmp = alloca(tmplen);
+	if (tmp == NULL)
+		return -ENOMEM;
+
+	hLen = crypt_hmac_size(hash);
+	if (hLen == 0 || hLen > MAX_PRF_BLOCK_LEN)
+		return -EINVAL;
+
+	if (c == 0)
+		return -EINVAL;
+
+	if (dkLen == 0)
+		return -EINVAL;
+
+	/*
+	 *
+	 *  Steps:
+	 *
+	 *     1. If dkLen > (2^32 - 1) * hLen, output "derived key too long" and
+	 *        stop.
+	 */
+
+	if (dkLen > 4294967295U)
+		return -EINVAL;
+
+	/*
+	 *     2. Let l be the number of hLen-octet blocks in the derived key,
+	 *        rounding up, and let r be the number of octets in the last
+	 *        block:
+	 *
+	 *                  l = CEIL (dkLen / hLen) ,
+	 *                  r = dkLen - (l - 1) * hLen .
+	 *
+	 *        Here, CEIL (x) is the "ceiling" function, i.e. the smallest
+	 *        integer greater than, or equal to, x.
+	 */
+
+	l = dkLen / hLen;
+	if (dkLen % hLen)
+		l++;
+	r = dkLen - (l - 1) * hLen;
+
+	/*
+	 *     3. For each block of the derived key apply the function F defined
+	 *        below to the password P, the salt S, the iteration count c, and
+	 *        the block index to compute the block:
+	 *
+	 *                  T_1 = F (P, S, c, 1) ,
+	 *                  T_2 = F (P, S, c, 2) ,
+	 *                  ...
+	 *                  T_l = F (P, S, c, l) ,
+	 *
+	 *        where the function F is defined as the exclusive-or sum of the
+	 *        first c iterates of the underlying pseudorandom function PRF
+	 *        applied to the password P and the concatenation of the salt S
+	 *        and the block index i:
+	 *
+	 *                  F (P, S, c, i) = U_1 \xor U_2 \xor ... \xor U_c
+	 *
+	 *        where
+	 *
+	 *                  U_1 = PRF (P, S || INT (i)) ,
+	 *                  U_2 = PRF (P, U_1) ,
+	 *                  ...
+	 *                  U_c = PRF (P, U_{c-1}) .
+	 *
+	 *        Here, INT (i) is a four-octet encoding of the integer i, most
+	 *        significant octet first.
+	 *
+	 *     4. Concatenate the blocks and extract the first dkLen octets to
+	 *        produce a derived key DK:
+	 *
+	 *                  DK = T_1 || T_2 ||  ...  || T_l<0..r-1>
+	 *
+	 *     5. Output the derived key DK.
+	 *
+	 *  Note. The construction of the function F follows a "belt-and-
+	 *  suspenders" approach. The iterates U_i are computed recursively to
+	 *  remove a degree of parallelism from an opponent; they are exclusive-
+	 *  ored together to reduce concerns about the recursion degenerating
+	 *  into a small set of values.
+	 *
+	 */
+
+	if (crypt_hmac_init(&hmac, hash, P, Plen))
+		return -EINVAL;
+
+	for (i = 1; (unsigned int) i <= l; i++) {
+		memset(T, 0, hLen);
+
+		for (u = 1; u <= c ; u++) {
+			if (u == 1) {
+				memcpy(tmp, S, Slen);
+				tmp[Slen + 0] = (i & 0xff000000) >> 24;
+				tmp[Slen + 1] = (i & 0x00ff0000) >> 16;
+				tmp[Slen + 2] = (i & 0x0000ff00) >> 8;
+				tmp[Slen + 3] = (i & 0x000000ff) >> 0;
+
+				if (crypt_hmac_write(hmac, tmp, tmplen))
+					goto out;
+			} else {
+				if (crypt_hmac_write(hmac, U, hLen))
+					goto out;
+			}
+
+			if (crypt_hmac_final(hmac, U, hLen))
+				goto out;
+
+			for (k = 0; (unsigned int) k < hLen; k++)
+				T[k] ^= U[k];
+		}
+
+		memcpy(DK + (i - 1) * hLen, T, (unsigned int) i == l ? r : hLen);
+	}
+	rc = 0;
+out:
+	crypt_hmac_destroy(hmac);
+	return rc;
+}