- started to implement diffie hellman class

2005-11-17 17:22:08 +00:00
parent c1e9c3f697
commit 4750f6c667
10 changed files with 388 additions and 16 deletions
@@ -0,0 +1,170 @@
+/**
+ * @file gmp_helper.c
+ * 
+ * @brief Class with helper functions for gmp operations
+ * 
+ */
+
+/*
+ * 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 "gmp_helper.h"
+
+#include "allocator.h"
+#include "randomizer.h"
+
+/**
+ * Private data of an gmp_helper_t object.
+ * 
+ */
+typedef struct private_gmp_helper_s private_gmp_helper_t;
+
+struct private_gmp_helper_s {
+	/**
+	 * public gmp_helper_t interface
+	 */
+	gmp_helper_t public;
+
+};
+
+
+/**
+ * Implements private_gmp_helper_t's chunk_to_mpz function.
+ * See #private_gmp_helper_t.chunk_to_mpz for description.
+ */
+static void chunk_to_mpz(private_gmp_helper_t *this, mpz_t *mpz_value, chunk_t data)
+{
+    size_t i;
+
+    mpz_init_set_ui(*(mpz_value), 0);
+
+    for (i = 0; i < data.len; i++)
+    {
+		mpz_mul_ui(*(mpz_value),*(mpz_value), 1 << 8);
+		mpz_add_ui(*(mpz_value),*(mpz_value), data.ptr[i]);
+    }
+}
+
+/**
+ * Implements private_gmp_helper_t's mpz_to_chunk function.
+ * See #private_gmp_helper_t.mpz_to_chunk for description.
+ */
+static status_t mpz_to_chunk (private_gmp_helper_t *this,mpz_t *mpz_value, chunk_t *data,size_t bytes)
+{
+    mpz_t temp1, temp2;
+    status_t status = SUCCESS;
+    int i;
+
+    data->len = bytes;
+    data->ptr = allocator_alloc(data->len);
+    
+    if (data->ptr == NULL)
+    {
+	    	return OUT_OF_RES;
+    }
+
+    /* free memory */
+    memset(data->ptr,0,data->len);
+
+    mpz_init(temp1);
+    mpz_init(temp2);
+
+    mpz_set(temp1, *mpz_value);
+
+    for (i = data->len-1; i >= 0; i--)
+    {
+		data->ptr[i] = mpz_mdivmod_ui(temp2, NULL, temp1, 1 << 8);
+		mpz_set(temp1, temp2);
+
+    }
+
+    if (mpz_sgn(temp1) != 0)
+    {
+		status = FAILED;
+    }
+    mpz_clear(temp1);
+    mpz_clear(temp2);
+    return status;
+}
+
+/**
+ * Implements gmp_helper_t's init_prime function.
+ * See #gmp_helper_t.init_prime for description.
+ */
+static status_t init_prime (private_gmp_helper_t *this, mpz_t *prime, int bytes)
+{
+    randomizer_t *randomizer;
+    chunk_t random_bytes;
+    status_t status;  
+    randomizer = randomizer_create();
+    
+    if (randomizer == NULL)
+    {
+    		return OUT_OF_RES;
+    } 
+    
+   	status = randomizer->allocate_random_bytes(randomizer,bytes, &random_bytes);
+   	/* not needed anymore */
+   	randomizer->destroy(randomizer);
+   	if (status != SUCCESS)
+   	{
+   		return status;
+   	}
+   	
+   	/* convert chunk to mpz value */
+   	this->public.chunk_to_mpz(&(this->public),prime, random_bytes);
+
+   	/* chunk is not used anymore */
+   	allocator_free(random_bytes.ptr);
+   	random_bytes.ptr = NULL;   
+
+	mpz_nextprime (*(prime),*(prime));
+
+	return SUCCESS;
+}
+
+
+
+/**
+ * Implements gmp_helper_t's destroy function.
+ * See #gmp_helper_t.destroy for description.
+ */
+static status_t destroy(private_gmp_helper_t *this)
+{
+	allocator_free(this);
+	return SUCCESS;
+}
+
+/*
+ * Described in header
+ */
+gmp_helper_t *gmp_helper_create()
+{
+	private_gmp_helper_t *this = allocator_alloc_thing(private_gmp_helper_t);
+	if ((this == NULL))
+	{
+		return NULL;
+	}
+	
+	/* public functions */
+	this->public.destroy = (status_t (*)(gmp_helper_t *)) destroy;
+	this->public.init_prime = (status_t (*) (gmp_helper_t *, mpz_t *, int)) init_prime;
+	
+	/* private functions */	
+	this->public.chunk_to_mpz = (void (*) (gmp_helper_t *,mpz_t *, chunk_t )) chunk_to_mpz;
+	this->public.mpz_to_chunk = (status_t (*) (gmp_helper_t *,mpz_t *, chunk_t *,size_t )) mpz_to_chunk;
+	
+	return &(this->public);
+}