added API for random number generators, served through credential factory

ported randomizer_t to a rng_t on top of /dev/(u)random (plugin random)

src/libstrongswan/plugins/gmp/gmp_diffie_hellman.c

@@ -22,7 +22,6 @@
 
 #include "gmp_diffie_hellman.h"
 
-#include <utils/randomizer.h>
 #include <debug.h>
 
 
@@ -521,9 +520,8 @@ static void destroy(private_gmp_diffie_hellman_t *this)
 gmp_diffie_hellman_t *gmp_diffie_hellman_create(diffie_hellman_group_t group)
 {
 	private_gmp_diffie_hellman_t *this = malloc_thing(private_gmp_diffie_hellman_t);
-	randomizer_t *randomizer;
+	rng_t *rng;
 	chunk_t random;
-	status_t status;
 
 	/* public functions */
 	this->public.dh.get_shared_secret = (status_t (*)(diffie_hellman_t *, chunk_t *)) get_shared_secret;
@@ -550,15 +548,15 @@ gmp_diffie_hellman_t *gmp_diffie_hellman_create(diffie_hellman_group_t group)
 		destroy(this);
 		return NULL;
 	}
-	randomizer = randomizer_create();
-	status = randomizer->allocate_pseudo_random_bytes(
-											randomizer, this->p_len, &random);
-	randomizer->destroy(randomizer);
-	if (status != SUCCESS)
+	rng = lib->crypto->create_rng(lib->crypto, RNG_STRONG);
+	if (!rng)
 	{
+		DBG1("no RNG found for quality %N", rng_quality_names, RNG_STRONG);
 		destroy(this);
 		return NULL;
 	}
+	rng->allocate_bytes(rng, this->p_len, &random);
+	rng->destroy(rng);
 	mpz_import(this->xa, random.len, 1, 1, 1, 0, random.ptr);
 	chunk_free(&random);
 	

src/libstrongswan/plugins/gmp/gmp_rsa_private_key.c

@@ -26,8 +26,6 @@
 
 #include <debug.h>
 #include <asn1/asn1.h>
-#include <utils/randomizer.h>
-#include <crypto/hashers/hasher.h>
 
 /**
  *  Public exponent to use for key generation.
@@ -151,23 +149,17 @@ bool gmp_rsa_public_key_build_id(mpz_t n, mpz_t e, identification_t **keyid,
 gmp_rsa_public_key_t *gmp_rsa_public_key_create_from_n_e(mpz_t n, mpz_t e);
 
 /**
- * Auxiliary function overwriting private key material with
- * pseudo-random bytes before releasing it
+ * Auxiliary function overwriting private key material with zero bytes
  */
 static void mpz_clear_randomized(mpz_t z)
 {
 	size_t len = mpz_size(z) * GMP_LIMB_BITS / BITS_PER_BYTE;
-	u_int8_t *random_bytes = alloca(len);
-
-	randomizer_t *randomizer = randomizer_create();
+	u_int8_t *random = alloca(len);
 	
-	randomizer->get_pseudo_random_bytes(randomizer, len, random_bytes);
-
-	/* overwrite mpz_t with pseudo-random bytes before clearing it */
-	mpz_import(z, len, 1, 1, 1, 0, random_bytes);
+	memset(random, 0, len);
+	/* overwrite mpz_t with zero bytes before clearing it */
+	mpz_import(z, len, 1, 1, 1, 0, random);
 	mpz_clear(z);
-
-	randomizer->destroy(randomizer);
 }
 
 /**
@@ -176,34 +168,31 @@ static void mpz_clear_randomized(mpz_t z)
 static status_t compute_prime(private_gmp_rsa_private_key_t *this,
 							  size_t prime_size, mpz_t *prime)
 {
-	randomizer_t *randomizer;
+	rng_t *rng;
 	chunk_t random_bytes;
-	status_t status;
 	
-	randomizer = randomizer_create();
+	rng = lib->crypto->create_rng(lib->crypto, RNG_REAL);
+	if (!rng)
+	{
+		DBG1("no RNG of quality %N found", rng_quality_names, RNG_REAL);
+		return FAILED;
+	}
+	
 	mpz_init(*prime);
-	
 	do
 	{
-		status = randomizer->allocate_random_bytes(randomizer, prime_size,
-												   &random_bytes);
-		if (status != SUCCESS)
-		{
-			randomizer->destroy(randomizer);
-			mpz_clear(*prime);
-			return FAILED;
-		}
+		rng->allocate_bytes(rng, prime_size, &random_bytes);
 		/* make sure most significant bit is set */
 		random_bytes.ptr[0] = random_bytes.ptr[0] | 0x80;
 		
 		mpz_import(*prime, random_bytes.len, 1, 1, 1, 0, random_bytes.ptr);
 		mpz_nextprime (*prime, *prime);
-		chunk_free_randomized(&random_bytes);
+		chunk_clear(&random_bytes);
 	}
 	/* check if it isn't too large */
 	while (((mpz_sizeinbase(*prime, 2) + 7) / 8) > prime_size);
 	
-	randomizer->destroy(randomizer);
+	rng->destroy(rng);
 	return SUCCESS;
 }
 
@@ -705,7 +694,7 @@ static gmp_rsa_private_key_t *load(chunk_t blob)
 	{
 		if (!extract_object(privkey_objects, &objectID, &object, &level, &ctx))
 		{
-			chunk_free_randomized(&blob);
+			chunk_clear(&blob);
 			destroy(this);
 			return NULL;
 		}
@@ -714,7 +703,7 @@ static gmp_rsa_private_key_t *load(chunk_t blob)
 			case PRIV_KEY_VERSION:
 				if (object.len > 0 && *object.ptr != 0)
 				{
-					chunk_free_randomized(&blob);
+					chunk_clear(&blob);
 					destroy(this);
 					return NULL;
 				}
@@ -746,7 +735,7 @@ static gmp_rsa_private_key_t *load(chunk_t blob)
 		}
 		objectID++;
 	}
-	chunk_free_randomized(&blob);
+	chunk_clear(&blob);
 	
 	this->k = (mpz_sizeinbase(this->n, 2) + 7) / BITS_PER_BYTE;
 	if (!gmp_rsa_public_key_build_id(this->n, this->e,

src/libstrongswan/plugins/random/Makefile.am

@@ -0,0 +1,11 @@
+
+INCLUDES = -I$(top_srcdir)/src/libstrongswan
+
+AM_CFLAGS = -rdynamic
+
+plugin_LTLIBRARIES = libstrongswan-random.la
+
+libstrongswan_random_la_SOURCES = random_plugin.h random_plugin.c \
+  random_rng.c random_rng.h
+libstrongswan_random_la_LDFLAGS = -module
+

src/libstrongswan/plugins/random/random_plugin.c

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2008 Martin Willi
+ * 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.
+ *
+ * $Id$
+ */
+
+#include "random_plugin.h"
+
+#include <library.h>
+#include "random_rng.h"
+
+typedef struct private_random_plugin_t private_random_plugin_t;
+
+/**
+ * private data of random_plugin
+ */
+struct private_random_plugin_t {
+
+	/**
+	 * public functions
+	 */
+	random_plugin_t public;
+};
+
+/**
+ * Implementation of random_plugin_t.gmptroy
+ */
+static void destroy(private_random_plugin_t *this)
+{
+	lib->crypto->remove_rng(lib->crypto,
+							(rng_constructor_t)random_rng_create);
+	free(this);
+}
+
+/*
+ * see header file
+ */
+plugin_t *plugin_create()
+{
+	private_random_plugin_t *this = malloc_thing(private_random_plugin_t);
+	
+	this->public.plugin.destroy = (void(*)(plugin_t*))destroy;
+	
+	lib->crypto->add_rng(lib->crypto, RNG_STRONG, 
+						 (rng_constructor_t)random_rng_create);
+	lib->crypto->add_rng(lib->crypto, RNG_REAL, 
+						 (rng_constructor_t)random_rng_create);
+	
+	return &this->public.plugin;
+}
+

src/libstrongswan/plugins/random/random_plugin.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2008 Martin Willi
+ * 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 random_p random
+ * @ingroup plugins
+ * 
+ * @defgroup random_plugin random_plugin
+ * @{ @ingroup random_p
+ */
+
+#ifndef RANDOM_PLUGIN_H_
+#define RANDOM_PLUGIN_H_
+
+#include <plugins/plugin.h>
+
+typedef struct random_plugin_t random_plugin_t;
+
+/**
+ * Plugin implementing a RNG reading from /dev/[u]random.
+ */
+struct random_plugin_t {
+
+	/**
+	 * implements plugin interface
+	 */
+	plugin_t plugin;
+};
+
+/**
+ * Create a random_plugin instance.
+ */
+plugin_t *plugin_create();
+
+#endif /* RANDOM_PLUGIN_H_ @}*/

src/libstrongswan/plugins/random/random_rng.c

@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2005-2008 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * 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.
+ *
+ * $Id$
+ */
+
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <debug.h>
+
+#include "random_rng.h"
+
+#ifndef DEV_RANDOM
+# define DEV_RANDOM "/dev/random"
+#endif
+
+#ifndef DEV_URANDOM
+# define DEV_URANDOM "/dev/urandom"
+#endif
+
+typedef struct private_random_rng_t private_random_rng_t;
+
+/**
+ * Private data of an random_rng_t object.
+ */
+struct private_random_rng_t {
+
+	/**
+	 * Public random_rng_t interface.
+	 */
+	random_rng_t public;
+	
+	/**
+	 * random device, depends on quality
+	 */
+	int dev;
+	
+	/**
+	 * file we read random bytes from
+	 */
+	char *file;
+};
+
+/**
+ * Implementation of random_rng_t.get_bytes.
+ */
+static void get_bytes(private_random_rng_t *this, size_t bytes,
+					  u_int8_t *buffer)
+{
+	size_t done, got;
+	
+	done = 0;
+	
+	while (done < bytes)
+	{
+		got = read(this->dev, buffer + done, bytes - done);
+		if (got <= 0)
+		{
+			DBG1("reading from \"%s\" failed: %s, retrying...",
+				 this->file, strerror(errno));
+			close(this->dev);
+			sleep(1);
+			this->dev = open(this->file, 0);
+		}
+		done += got;
+	}
+}
+
+/**
+ * Implementation of random_rng_t.allocate_bytes.
+ */
+static void allocate_bytes(private_random_rng_t *this, size_t bytes,
+						   chunk_t *chunk)
+{
+	*chunk = chunk_alloc(bytes);
+	get_bytes(this, chunk->len, chunk->ptr);
+}
+
+/**
+ * Implementation of random_rng_t.destroy.
+ */
+static void destroy(private_random_rng_t *this)
+{
+	close(this->dev);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+random_rng_t *random_rng_create(rng_quality_t quality)
+{
+	private_random_rng_t *this = malloc_thing(private_random_rng_t);
+
+	/* public functions */
+	this->public.rng.get_bytes = (void (*) (rng_t *, size_t, u_int8_t*)) get_bytes;
+	this->public.rng.allocate_bytes = (void (*) (rng_t *, size_t, chunk_t*)) allocate_bytes;
+	this->public.rng.destroy = (void (*) (rng_t *))destroy;
+
+	if (quality == RNG_REAL)
+	{
+		this->file = DEV_RANDOM;
+	}
+	else
+	{
+		this->file = DEV_URANDOM;
+	}
+	
+	this->dev = open(this->file, 0);
+	if (this->dev < 0)
+	{
+		DBG1("opening \"%s\" failed: %s", this->file, strerror(errno));
+		free(this);
+		return NULL;
+	}
+	return &this->public;
+}
+

src/libstrongswan/plugins/random/random_rng.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2008 Martin Willi
+ * 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.
+ *
+ * $Id$
+ */
+ 
+/**
+ * @defgroup random_rng random_rng
+ * @{ @ingroup utils
+ */
+
+#ifndef RANDOM_RNG_H_
+#define RANDOM_RNG_H_
+
+typedef struct random_rng_t random_rng_t;
+
+#include <library.h>
+
+/**
+ * rng_t implementation on top of /dev/[u]random
+ */
+struct random_rng_t {
+	
+	/**
+	 * Implements rng_t.
+	 */
+	rng_t rng;
+};
+
+/**
+ * Creates an random_rng_t instance.
+ * 
+ * @param quality	required quality of randomness
+ * @return			created random_rng_t
+ */
+random_rng_t *random_rng_create(rng_quality_t quality);
+
+#endif /*RANDOM_RNG_H_ @} */

src/libstrongswan/plugins/x509/x509_ocsp_request.c

@@ -23,7 +23,6 @@
 #include <asn1/oid.h>
 #include <asn1/asn1.h>
 #include <utils/identification.h>
-#include <utils/randomizer.h>
 #include <utils/linked_list.h>
 #include <debug.h>
 #include <credentials/certificates/x509.h>
@@ -205,14 +204,18 @@ static chunk_t build_requestList(private_x509_ocsp_request_t *this)
  */
 static chunk_t build_nonce(private_x509_ocsp_request_t *this)
 {
-	randomizer_t *randomizer;
+	rng_t *rng;
 	
-	randomizer = randomizer_create();
-	randomizer->allocate_pseudo_random_bytes(randomizer, NONCE_LEN, &this->nonce);
-	randomizer->destroy(randomizer);
-	
-    return asn1_wrap(ASN1_SEQUENCE, "cm", ASN1_nonce_oid,
-				asn1_simple_object(ASN1_OCTET_STRING, this->nonce));
+	rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
+	if (rng)
+	{
+		rng->allocate_bytes(rng, NONCE_LEN, &this->nonce);
+		rng->destroy(rng);
+		return asn1_wrap(ASN1_SEQUENCE, "cm", ASN1_nonce_oid,
+					asn1_simple_object(ASN1_OCTET_STRING, this->nonce));
+	}
+	DBG1("creating OCSP request nonce failed, no RNG found");
+	return chunk_empty;
 }
 
 /**