- AUTH_HMAC_MD5_96 and AUTH_HMAC_SHA1_96 implemented and tested...

Source/charon/transforms/signers/hmac_signer.c

@@ -0,0 +1,184 @@
+/**
+ * @file hmac_signer.c
+ * 
+ * @brief Implementation of hmac_signer_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, 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.
+ */
+
+#include "hmac_signer.h"
+
+#include <utils/allocator.h>
+#include <transforms/prfs/prf_hmac.h>
+
+/**
+ * This class represents a hmac signer with 12 byte (96 bit) output
+ */
+#define BLOCK_SIZE	12
+
+typedef struct private_hmac_signer_t private_hmac_signer_t;
+
+/**
+ * private data structure with signing context.
+ */
+struct private_hmac_signer_t {
+	/**
+	 * Public interface for this signer.
+	 */
+	hmac_signer_t public;
+	
+	/*
+	 * Assigned hmac function.
+	 */
+	prf_t *hmac_prf;
+};
+
+
+static status_t get_signature (private_hmac_signer_t *this, chunk_t data, u_int8_t *buffer)
+{
+	u_int8_t full_mac[this->hmac_prf->get_block_size(this->hmac_prf)];
+	status_t status;
+	
+	status = this->hmac_prf->get_bytes(this->hmac_prf,data,full_mac);
+	if (status != SUCCESS)
+	{
+		return status;
+	}
+
+	/* copy mac aka signature :-) */
+	memcpy(buffer,full_mac,BLOCK_SIZE);
+		
+	return SUCCESS;
+}
+
+static status_t allocate_signature (private_hmac_signer_t *this, chunk_t data, chunk_t *chunk)
+{
+	chunk_t signature;
+	status_t status;
+	u_int8_t full_mac[this->hmac_prf->get_block_size(this->hmac_prf)];
+	
+	status = this->hmac_prf->get_bytes(this->hmac_prf,data,full_mac);
+	if (status != SUCCESS)
+	{
+		return status;
+	}
+	
+	signature.ptr = allocator_alloc(BLOCK_SIZE);
+	if (signature.ptr == NULL)
+	{
+		return OUT_OF_RES;
+	}
+	signature.len = BLOCK_SIZE;
+	
+	/* copy mac aka signature :-) */
+	memcpy(signature.ptr,full_mac,BLOCK_SIZE);
+
+	*chunk = signature;
+		
+	return SUCCESS;
+
+}
+
+static status_t verify_signature (private_hmac_signer_t *this, chunk_t data, chunk_t signature, bool *valid)
+{
+	status_t status;
+	u_int8_t full_mac[this->hmac_prf->get_block_size(this->hmac_prf)];
+	
+	status = this->hmac_prf->get_bytes(this->hmac_prf,data,full_mac);
+	if (status != SUCCESS)
+	{
+		return status;
+	}
+	
+	if (signature.len != BLOCK_SIZE)
+	{
+		/* signature must have BLOCK_SIZE length */
+		return INVALID_ARG;
+	}
+	
+	/* compare mac aka signature :-) */
+	if (memcmp(signature.ptr,full_mac,BLOCK_SIZE) == 0)
+	{
+		*valid = TRUE;
+	}
+	else
+	{
+		*valid = FALSE;
+	}
+		
+	return SUCCESS;
+}
+	
+static size_t get_block_size (private_hmac_signer_t *this)
+{
+	return BLOCK_SIZE;
+}
+	
+static status_t set_key (private_hmac_signer_t *this, chunk_t key)
+{
+	return (this->hmac_prf->set_key(this->hmac_prf,key));
+}
+
+/**
+ * implementation of signer_t.destroy.
+ */
+static status_t destroy(private_hmac_signer_t *this)
+{
+	this->hmac_prf->destroy(this->hmac_prf);
+	allocator_free(this);
+	return SUCCESS;
+}
+
+
+/*
+ * Described in header
+ */
+hmac_signer_t *hmac_signer_create(hash_algorithm_t hash_algoritm)
+{
+	private_hmac_signer_t *this = allocator_alloc_thing(private_hmac_signer_t);
+	if (this == NULL)
+	{
+		return NULL;	
+	}
+	
+	this->hmac_prf = (prf_t *) prf_hmac_create(hash_algoritm);
+	
+	if (this->hmac_prf == NULL)
+	{
+		/* hmac prf could not be created !!! */
+		allocator_free(this);
+		return NULL;
+	}
+	
+	if (this->hmac_prf->get_block_size(this->hmac_prf) < BLOCK_SIZE)
+	{
+		/* hmac prf with given algorithm has to small block size */
+		allocator_free(this);
+		return NULL;
+		
+	}
+	
+	/* interface functions */
+	this->public.signer_interface.get_signature = (status_t (*) (signer_t*, chunk_t, u_int8_t*))get_signature;
+	this->public.signer_interface.allocate_signature = (status_t (*) (signer_t*, chunk_t, chunk_t*))allocate_signature;
+	this->public.signer_interface.verify_signature = (status_t (*) (signer_t*, chunk_t, chunk_t,bool *))verify_signature;
+	this->public.signer_interface.get_block_size = (size_t (*) (signer_t*))get_block_size;
+	this->public.signer_interface.set_key = (size_t (*) (signer_t*,chunk_t))set_key;
+	this->public.signer_interface.destroy = (status_t (*) (signer_t*))destroy;
+	
+	return &(this->public);
+}