Implemented the TLS specific PRF in its TLSv1.0 and TLSv1.2 variants

3 files changed, 263 insertions, 0 deletions

diff --git a/src/charon/plugins/eap_tls/Makefile.am b/src/charon/plugins/eap_tls/Makefile.am
index 75e9cfbaa..d18dda2aa 100644
--- a/src/charon/plugins/eap_tls/Makefile.am
+++ b/src/charon/plugins/eap_tls/Makefile.am
@@ -11,6 +11,7 @@ libstrongswan_eap_tls_la_SOURCES = eap_tls_plugin.h eap_tls_plugin.c \
 	tls/tls_compression.h tls/tls_compression.c \
 	tls/tls_fragmentation.h tls/tls_fragmentation.c \
 	tls/tls_crypto.h tls/tls_crypto.c \
+	tls/tls_prf.h tls/tls_prf.c \
 	tls/tls_reader.h tls/tls_reader.c \
 	tls/tls_writer.h tls/tls_writer.c \
 	tls/tls_peer.h tls/tls_peer.c \
diff --git a/src/charon/plugins/eap_tls/tls/tls_prf.c b/src/charon/plugins/eap_tls/tls/tls_prf.c
new file mode 100644
index 000000000..f181d01d3
--- /dev/null
+++ b/src/charon/plugins/eap_tls/tls/tls_prf.c
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * 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 "tls_prf.h"
+
+typedef struct private_tls_prf12_t private_tls_prf12_t;
+
+/**
+ * Private data of an tls_prf_t object.
+ */
+struct private_tls_prf12_t {
+
+	/**
+	 * Public tls_prf_t interface.
+	 */
+	tls_prf_t public;
+
+	/**
+	 * Underlying primitive PRF
+	 */
+	prf_t *prf;
+};
+
+METHOD(tls_prf_t, set_key12, void,
+	private_tls_prf12_t *this, chunk_t key)
+{
+	this->prf->set_key(this->prf, key);
+}
+
+/**
+ * The P_hash function as in TLS 1.0/1.2
+ */
+static void p_hash(prf_t *prf, char *label, chunk_t seed, size_t block_size,
+				   size_t bytes, char *out)
+{
+	char buf[block_size], abuf[block_size];
+	chunk_t a;
+
+	/* seed = label + seed */
+	seed = chunk_cata("cc", chunk_create(label, strlen(label)), seed);
+	/* A(0) = seed */
+	a = seed;
+
+	while (TRUE)
+	{
+		/* A(i) = HMAC_hash(secret, A(i-1)) */
+		prf->get_bytes(prf, a, abuf);
+		a = chunk_from_thing(abuf);
+		/* HMAC_hash(secret, A(i) + seed) */
+		prf->get_bytes(prf, a, NULL);
+		prf->get_bytes(prf, seed, buf);
+
+		if (bytes <= block_size)
+		{
+			memcpy(out, buf, bytes);
+			break;
+		}
+		memcpy(out, buf, block_size);
+		out += block_size;
+		bytes -= block_size;
+	}
+}
+
+METHOD(tls_prf_t, get_bytes12, void,
+	private_tls_prf12_t *this, char *label, chunk_t seed,
+	size_t bytes, char *out)
+{
+	p_hash(this->prf, label, seed, this->prf->get_block_size(this->prf),
+		   bytes, out);
+}
+
+METHOD(tls_prf_t, destroy12, void,
+	private_tls_prf12_t *this)
+{
+	this->prf->destroy(this->prf);
+	free(this);
+}
+
+/**
+ * See header
+ */
+tls_prf_t *tls_prf_create_12(pseudo_random_function_t prf)
+{
+	private_tls_prf12_t *this;
+
+	INIT(this,
+		.public = {
+			.set_key = _set_key12,
+			.get_bytes = _get_bytes12,
+			.destroy = _destroy12,
+		},
+		.prf = lib->crypto->create_prf(lib->crypto, prf),
+	);
+	if (!this->prf)
+	{
+		free(this);
+		return NULL;
+	}
+	return &this->public;
+}
+
+
+typedef struct private_tls_prf10_t private_tls_prf10_t;
+
+/**
+ * Private data of an tls_prf_t object.
+ */
+struct private_tls_prf10_t {
+
+	/**
+	 * Public tls_prf_t interface.
+	 */
+	tls_prf_t public;
+
+	/**
+	 * Underlying MD5 PRF
+	 */
+	prf_t *md5;
+
+	/**
+	 * Underlying SHA1 PRF
+	 */
+	prf_t *sha1;
+};
+
+METHOD(tls_prf_t, set_key10, void,
+	private_tls_prf10_t *this, chunk_t key)
+{
+	size_t len = key.len / 2 + key.len % 2;
+
+	this->md5->set_key(this->md5, chunk_create(key.ptr, len));
+	this->sha1->set_key(this->sha1, chunk_create(key.ptr + key.len - len, len));
+}
+
+METHOD(tls_prf_t, get_bytes10, void,
+	private_tls_prf10_t *this, char *label, chunk_t seed,
+	size_t bytes, char *out)
+{
+	char buf[bytes];
+
+	p_hash(this->md5, label, seed, this->md5->get_block_size(this->md5),
+		   bytes, out);
+	p_hash(this->sha1, label, seed, this->sha1->get_block_size(this->sha1),
+		   bytes, buf);
+	memxor(out, buf, bytes);
+}
+
+METHOD(tls_prf_t, destroy10, void,
+	private_tls_prf10_t *this)
+{
+	DESTROY_IF(this->md5);
+	DESTROY_IF(this->sha1);
+	free(this);
+}
+
+/**
+ * See header
+ */
+tls_prf_t *tls_prf_create_10(pseudo_random_function_t prf)
+{
+	private_tls_prf10_t *this;
+
+	INIT(this,
+		.public = {
+			.set_key = _set_key10,
+			.get_bytes = _get_bytes10,
+			.destroy = _destroy10,
+		},
+		.md5 = lib->crypto->create_prf(lib->crypto, PRF_HMAC_MD5),
+		.sha1 = lib->crypto->create_prf(lib->crypto, PRF_HMAC_SHA1),
+	);
+	if (!this->md5 || !this->sha1)
+	{
+		destroy10(this);
+		return NULL;
+	}
+	return &this->public;
+}
diff --git a/src/charon/plugins/eap_tls/tls/tls_prf.h b/src/charon/plugins/eap_tls/tls/tls_prf.h
new file mode 100644
index 000000000..7326be98c
--- /dev/null
+++ b/src/charon/plugins/eap_tls/tls/tls_prf.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * 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 tls_prf tls_prf
+ * @{ @ingroup tls
+ */
+
+#ifndef TLS_PRF_H_
+#define TLS_PRF_H_
+
+typedef struct tls_prf_t tls_prf_t;
+
+#include <crypto/prfs/prf.h>
+
+/**
+ * The PRF function specified on TLS, based on HMAC.
+ */
+struct tls_prf_t {
+
+	/**
+	 * Set the key of the PRF function.
+	 *
+	 * @param key		key to set
+	 */
+	void (*set_key)(tls_prf_t *this, chunk_t key);
+
+	/**
+	 * Generate a series of bytes using a label and a seed.
+	 *
+	 * @param label		ASCII input label
+	 * @param seed		seed input value
+	 * @param bytes		number of bytes to get
+	 * @param out		buffer receiving bytes
+	 */
+	void (*get_bytes)(tls_prf_t *this, char *label, chunk_t seed,
+					  size_t bytes, char *out);
+
+	/**
+	 * Destroy a tls_prf_t.
+	 */
+	void (*destroy)(tls_prf_t *this);
+};
+
+/**
+ * Create a tls_prf instance with specific algorithm as in TLS 1.2.
+ *
+ * @param hash			underlying PRF function to use
+ * @return				TLS PRF algorithm
+ */
+tls_prf_t *tls_prf_create_12(pseudo_random_function_t prf);
+
+/**
+ * Create a tls_prf instance with XOred SHA1/MD5 as in TLS 1.0/1.1.
+ *
+ * @return				TLS PRF algorithm
+ */
+tls_prf_t *tls_prf_create_10();
+
+#endif /** TLS_PRF_H_ @}*/