Fix PBKDF2 for crypto backens which does not support long HMAC keys.

(Or it rehases key in every iteration.)

- Kernel backens seems not to support >20480 HMAC key
- NSS is slow (without proper key reset)

Add some test vectors (commented out by default).

lib/crypto_backend/crypto_backend.h

@@ -2,7 +2,7 @@
  * crypto backend implementation
  *
  * Copyright (C) 2010-2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2010-2012, Milan Broz
+ * Copyright (C) 2010-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -72,7 +72,8 @@ 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);
+		 unsigned int dkLen, char *DK,
+		 unsigned int hash_block_size);
 #endif
 
 /* CRC32 */

lib/crypto_backend/crypto_cipher_kernel.c

@@ -2,7 +2,7 @@
  * Linux kernel userspace API crypto backend implementation (skcipher)
  *
  * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2012, Milan Broz
+ * Copyright (C) 2012-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

lib/crypto_backend/crypto_gcrypt.c

@@ -2,7 +2,7 @@
  * GCRYPT crypto backend implementation
  *
  * Copyright (C) 2010-2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2010-2012, Milan Broz
+ * Copyright (C) 2010-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -331,7 +331,7 @@ int crypt_pbkdf(const char *kdf, const char *hash,
 		return -EINVAL;
 
 	return pkcs5_pbkdf2(hash_name, password, password_length, salt, salt_length,
-			    iterations, key_length, key);
+			    iterations, key_length, key, 0);
 
 #else /* USE_INTERNAL_PBKDF2 */
 	int hash_id = gcry_md_map_name(hash_name);

lib/crypto_backend/crypto_kernel.c

@@ -2,7 +2,7 @@
  * Linux kernel userspace API crypto backend implementation
  *
  * Copyright (C) 2010-2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2010-2012, Milan Broz
+ * Copyright (C) 2010-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -44,15 +44,16 @@ struct hash_alg {
 	const char *name;
 	const char *kernel_name;
 	int length;
+	unsigned int block_length;
 };
 
 static struct hash_alg hash_algs[] = {
-	{ "sha1", "sha1", 20 },
+	{ "sha1",      "sha1",   20,  64 },
-	{ "sha256", "sha256", 32 },
+	{ "sha256",    "sha256", 32,  64 },
-	{ "sha512", "sha512", 64 },
+	{ "sha512",    "sha512", 64, 128 },
-	{ "ripemd160", "rmd160", 20 },
+	{ "ripemd160", "rmd160", 20,  64 },
-	{ "whirlpool", "wp512", 64 },
+	{ "whirlpool", "wp512",  64,  64 },
-	{ NULL, NULL, 0 }
+	{ NULL,        NULL,      0,   0 }
 };
 
 struct crypt_hash {
@@ -289,9 +290,11 @@ int crypt_pbkdf(const char *kdf, const char *hash,
 		char *key, size_t key_length,
 		unsigned int iterations)
 {
-	if (!kdf || strncmp(kdf, "pbkdf2", 6))
+	struct hash_alg *ha = _get_alg(hash);
+
+	if (!ha || !kdf || strncmp(kdf, "pbkdf2", 6))
 		return -EINVAL;
 
 	return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
-			    iterations, key_length, key);
+			    iterations, key_length, key, ha->block_length);
 }

lib/crypto_backend/crypto_nettle.c

@@ -2,7 +2,7 @@
  * Nettle crypto backend implementation
  *
  * Copyright (C) 2011-2012 Red Hat, Inc. All rights reserved.
- * Copyright (C) 2011-2012, Milan Broz
+ * Copyright (C) 2011-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -289,5 +289,5 @@ int crypt_pbkdf(const char *kdf, const char *hash,
 
 	/* FIXME: switch to internal implementation in Nettle 2.6 */
 	return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
-			    iterations, key_length, key);
+			    iterations, key_length, key, 0);
 }

lib/crypto_backend/crypto_nss.c

@@ -2,7 +2,7 @@
  * NSS crypto backend implementation
  *
  * Copyright (C) 2010-2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2010-2012, Milan Broz
+ * Copyright (C) 2010-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -35,14 +35,15 @@ struct hash_alg {
 	SECOidTag oid;
 	CK_MECHANISM_TYPE ck_type;
 	int length;
+	unsigned int block_length;
 };
 
 static struct hash_alg hash_algs[] = {
-	{ "sha1", SEC_OID_SHA1, CKM_SHA_1_HMAC, 20 },
+	{ "sha1",   SEC_OID_SHA1,   CKM_SHA_1_HMAC,  20,  64 },
-	{ "sha256", SEC_OID_SHA256, CKM_SHA256_HMAC, 32 },
+	{ "sha256", SEC_OID_SHA256, CKM_SHA256_HMAC, 32,  64 },
-	{ "sha384", SEC_OID_SHA384, CKM_SHA384_HMAC, 48 },
+	{ "sha384", SEC_OID_SHA384, CKM_SHA384_HMAC, 48, 128 },
-	{ "sha512", SEC_OID_SHA512, CKM_SHA512_HMAC, 64 },
+	{ "sha512", SEC_OID_SHA512, CKM_SHA512_HMAC, 64, 128 },
-//	{ "ripemd160", SEC_OID_RIPEMD160, CKM_RIPEMD160_HMAC, 20 },
+//	{ "ripemd160", SEC_OID_RIPEMD160, CKM_RIPEMD160_HMAC, 20, 64 },
 	{ NULL, 0, 0, 0 }
 };
 
@@ -308,9 +309,11 @@ int crypt_pbkdf(const char *kdf, const char *hash,
 		char *key, size_t key_length,
 		unsigned int iterations)
 {
-	if (!kdf || strncmp(kdf, "pbkdf2", 6))
+	struct hash_alg *ha = _get_alg(hash);
+
+	if (!ha || !kdf || strncmp(kdf, "pbkdf2", 6))
 		return -EINVAL;
 
 	return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
-			    iterations, key_length, key);
+			    iterations, key_length, key, ha->block_length);
 }

lib/crypto_backend/crypto_openssl.c

@@ -2,7 +2,7 @@
  * OPENSSL crypto backend implementation
  *
  * Copyright (C) 2010-2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2010-2012, Milan Broz
+ * Copyright (C) 2010-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

lib/crypto_backend/pbkdf2_generic.c

@@ -5,6 +5,7 @@
  *
  * cryptsetup related changes
  * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2012-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -26,6 +27,27 @@
 #include <alloca.h>
 #include "crypto_backend.h"
 
+static int pkcs5_pbkdf2_test_vectors(void);
+
+static int hash_buf(const char *src, size_t src_len,
+		    char *dst, size_t dst_len,
+		    const char *hash_name)
+{
+	struct crypt_hash *hd = NULL;
+	int r;
+
+	if (crypt_hash_init(&hd, hash_name))
+		return -EINVAL;
+
+	r = crypt_hash_write(hd, src, src_len);
+
+	if (!r)
+		r = crypt_hash_final(hd, dst, dst_len);
+
+	crypt_hash_destroy(hd);
+	return r;
+}
+
 /*
  * 5.2 PBKDF2
  *
@@ -52,17 +74,26 @@
  *  Output:         DK         derived key, a dkLen-octet string
  */
 
+/*
+ * if hash_block_size is not zero, the HMAC key is pre-hashed
+ * inside this function.
+ * This prevents situation when crypto backend doesn't support
+ * long HMAC keys or it tries hash long key in every iteration
+ * (because of crypt_final() cannot do simple key reset.
+ */
+
 #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)
+			char *DK, unsigned int hash_block_size)
 {
 	struct crypt_hmac *hmac;
 	char U[MAX_PRF_BLOCK_LEN];
 	char T[MAX_PRF_BLOCK_LEN];
+	char P_hash[MAX_PRF_BLOCK_LEN];
 	int i, k, rc = -EINVAL;
 	unsigned int u, hLen, l, r;
 	size_t tmplen = Slen + 4;
@@ -152,8 +183,18 @@ int pkcs5_pbkdf2(const char *hash,
 	 *
 	 */
 
+	/* If hash_block_size is provided, hash password in advance. */
+	if (hash_block_size > 0 && Plen > hash_block_size) {
+		if (hash_buf(P, Plen, P_hash, hLen, hash))
+			return -EINVAL;
+
+		if (crypt_hmac_init(&hmac, hash, P_hash, hLen))
+			return -EINVAL;
+		memset(P_hash, 0, sizeof(P_hash));
+	} else {
 		if (crypt_hmac_init(&hmac, hash, P, Plen))
 			return -EINVAL;
+	}
 
 	for (i = 1; (unsigned int) i <= l; i++) {
 		memset(T, 0, hLen);
@@ -185,5 +226,203 @@ int pkcs5_pbkdf2(const char *hash,
 	rc = 0;
 out:
 	crypt_hmac_destroy(hmac);
+	memset(U, 0, sizeof(U));
+	memset(T, 0, sizeof(T));
+	memset(tmp, 0, tmplen);
+
 	return rc;
 }
+
+#if 0
+#include <stdio.h>
+
+struct test_vector {
+	const char *hash;
+	unsigned int hash_block_length;
+	unsigned int iterations;
+	const char *password;
+	unsigned int password_length;
+	const char *salt;
+	unsigned int salt_length;
+	const char *output;
+	unsigned int output_length;
+};
+
+struct test_vector test_vectors[] = {
+	/* RFC 3962 */
+	{
+		"sha1", 64, 1,
+		"password", 8,
+		"ATHENA.MIT.EDUraeburn", 21,
+		"\xcd\xed\xb5\x28\x1b\xb2\xf8\x01"
+		"\x56\x5a\x11\x22\xb2\x56\x35\x15"
+		"\x0a\xd1\xf7\xa0\x4b\xb9\xf3\xa3"
+		"\x33\xec\xc0\xe2\xe1\xf7\x08\x37", 32
+	}, {
+		"sha1", 64, 2,
+		"password", 8,
+		"ATHENA.MIT.EDUraeburn", 21,
+		"\x01\xdb\xee\x7f\x4a\x9e\x24\x3e"
+		"\x98\x8b\x62\xc7\x3c\xda\x93\x5d"
+		"\xa0\x53\x78\xb9\x32\x44\xec\x8f"
+		"\x48\xa9\x9e\x61\xad\x79\x9d\x86", 32
+	}, {
+		"sha1", 64, 1200,
+		"password", 8,
+		"ATHENA.MIT.EDUraeburn", 21,
+		"\x5c\x08\xeb\x61\xfd\xf7\x1e\x4e"
+		"\x4e\xc3\xcf\x6b\xa1\xf5\x51\x2b"
+		"\xa7\xe5\x2d\xdb\xc5\xe5\x14\x2f"
+		"\x70\x8a\x31\xe2\xe6\x2b\x1e\x13", 32
+	}, {
+		"sha1", 64, 5,
+		"password", 8,
+		"\0224VxxV4\022", 8, // "\x1234567878563412
+		"\xd1\xda\xa7\x86\x15\xf2\x87\xe6"
+		"\xa1\xc8\xb1\x20\xd7\x06\x2a\x49"
+		"\x3f\x98\xd2\x03\xe6\xbe\x49\xa6"
+		"\xad\xf4\xfa\x57\x4b\x6e\x64\xee", 32
+	}, {
+		"sha1", 64, 1200,
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 64,
+		"pass phrase equals block size", 29,
+		"\x13\x9c\x30\xc0\x96\x6b\xc3\x2b"
+		"\xa5\x5f\xdb\xf2\x12\x53\x0a\xc9"
+		"\xc5\xec\x59\xf1\xa4\x52\xf5\xcc"
+		"\x9a\xd9\x40\xfe\xa0\x59\x8e\xd1", 32
+	}, {
+		"sha1", 64, 1200,
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 65,
+		"pass phrase exceeds block size", 30,
+		"\x9c\xca\xd6\xd4\x68\x77\x0c\xd5"
+		"\x1b\x10\xe6\xa6\x87\x21\xbe\x61"
+		"\x1a\x8b\x4d\x28\x26\x01\xdb\x3b"
+		"\x36\xbe\x92\x46\x91\x5e\xc8\x2a", 32
+	}, {
+		"sha1", 64, 50,
+		"\360\235\204\236", 4, // g-clef ("\xf09d849e)
+		"EXAMPLE.COMpianist", 18,
+		"\x6b\x9c\xf2\x6d\x45\x45\x5a\x43"
+		"\xa5\xb8\xbb\x27\x6a\x40\x3b\x39"
+		"\xe7\xfe\x37\xa0\xc4\x1e\x02\xc2"
+		"\x81\xff\x30\x69\xe1\xe9\x4f\x52", 32
+	}, {
+	/* RFC-6070 */
+		"sha1", 64, 1,
+		"password", 8,
+		"salt", 4,
+		"\x0c\x60\xc8\x0f\x96\x1f\x0e\x71\xf3\xa9"
+		"\xb5\x24\xaf\x60\x12\x06\x2f\xe0\x37\xa6", 20
+	}, {
+		"sha1", 64, 2,
+		"password", 8,
+		"salt", 4,
+		"\xea\x6c\x01\x4d\xc7\x2d\x6f\x8c\xcd\x1e"
+		"\xd9\x2a\xce\x1d\x41\xf0\xd8\xde\x89\x57", 20
+	}, {
+		"sha1", 64, 4096,
+		"password", 8,
+		"salt", 4,
+		"\x4b\x00\x79\x01\xb7\x65\x48\x9a\xbe\xad"
+		"\x49\xd9\x26\xf7\x21\xd0\x65\xa4\x29\xc1", 20
+	}, {
+		"sha1", 64, 16777216,
+		"password", 8,
+		"salt", 4,
+		"\xee\xfe\x3d\x61\xcd\x4d\xa4\xe4\xe9\x94"
+		"\x5b\x3d\x6b\xa2\x15\x8c\x26\x34\xe9\x84", 20
+	}, {
+		"sha1", 64, 4096,
+		"passwordPASSWORDpassword", 24,
+		"saltSALTsaltSALTsaltSALTsaltSALTsalt", 36,
+		"\x3d\x2e\xec\x4f\xe4\x1c\x84\x9b\x80\xc8"
+		"\xd8\x36\x62\xc0\xe4\x4a\x8b\x29\x1a\x96"
+		"\x4c\xf2\xf0\x70\x38", 25
+	}, {
+		"sha1", 64, 4096,
+		"pass\0word", 9,
+		"sa\0lt", 5,
+		"\x56\xfa\x6a\xa7\x55\x48\x09\x9d\xcc\x37"
+		"\xd7\xf0\x34\x25\xe0\xc3", 16
+	}, {
+	/* empty password test */
+		"sha1", 64, 2,
+		"", 0,
+		"salt", 4,
+		"\x13\x3a\x4c\xe8\x37\xb4\xd2\x52\x1e\xe2"
+		"\xbf\x03\xe1\x1c\x71\xca\x79\x4e\x07\x97", 20
+	}, {
+	/* Password exceeds block size test */
+		"sha256", 64, 1200,
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 65,
+		"pass phrase exceeds block size", 30,
+		"\x22\x34\x4b\xc4\xb6\xe3\x26\x75"
+		"\xa8\x09\x0f\x3e\xa8\x0b\xe0\x1d"
+		"\x5f\x95\x12\x6a\x2c\xdd\xc3\xfa"
+		"\xcc\x4a\x5e\x6d\xca\x04\xec\x58", 32
+	}, {
+		"sha512", 128, 1200,
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 129,
+		"pass phrase exceeds block size", 30,
+		"\x0f\xb2\xed\x2c\x0e\x6e\xfb\x7d"
+		"\x7d\x8e\xdd\x58\x01\xb4\x59\x72"
+		"\x99\x92\x16\x30\x5e\xa4\x36\x8d"
+		"\x76\x14\x80\xf3\xe3\x7a\x22\xb9", 32
+	}, {
+		"whirlpool", 64, 1200,
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+		"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", 65,
+		"pass phrase exceeds block size", 30,
+		"\x9c\x1c\x74\xf5\x88\x26\xe7\x6a"
+		"\x53\x58\xf4\x0c\x39\xe7\x80\x89"
+		"\x07\xc0\x31\x19\x9a\x50\xa2\x48"
+		"\xf1\xd9\xfe\x78\x64\xe5\x84\x50", 32
+	}
+};
+
+static void printhex(const char *s, const char *buf, size_t len)
+{
+	size_t i;
+
+	printf("%s: ", s);
+	for (i = 0; i < len; i++)
+		printf("\\x%02x", (unsigned char)buf[i]);
+	printf("\n");
+	fflush(stdout);
+}
+
+static int pkcs5_pbkdf2_test_vectors(void)
+{
+	char result[64];
+	unsigned int i, j;
+	struct test_vector *vec;
+
+	for (i = 0; i < (sizeof(test_vectors) / sizeof(*test_vectors)); i++) {
+		vec = &test_vectors[i];
+		for (j = 1; j <= vec->output_length; j++) {
+			if (pkcs5_pbkdf2(vec->hash,
+			    vec->password, vec->password_length,
+			    vec->salt, vec->salt_length,
+			    vec->iterations,
+			    j, result, vec->hash_block_length)) {
+				printf("pbkdf2 failed, vector %d\n", i);
+				return -EINVAL;
+			}
+			if (memcmp(result, vec->output, j) != 0) {
+				printf("vector %u\n", i);
+				printhex(" got", result, j);
+				printhex("want", vec->output, j);
+				return -EINVAL;
+			}
+			memset(result, 0, sizeof(result));
+		}
+	}
+	return 0;
+}
+#endif

lib/crypto_backend/pbkdf_check.c

@@ -1,7 +1,7 @@
 /*
  * PBKDF performance check
  * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2012, Milan Broz
+ * Copyright (C) 2012-2014, Milan Broz
  *
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public