- implemented RSA, only signing and verifying esma_pkcs1 padded

- removed gmp-helper: chunk_to_mpz is now done with gmp functions, prime generation in prime-pool - added prime-pool (needs priority fix) - proof of concept RSA authentication - mpz uses LEAK_DETECTIVE - configuration-manager supports rsa keys
2005-12-04 01:30:35 +00:00
parent a374d1ee66
commit 8ff8c33d1d
29 changed files with 2311 additions and 289 deletions
@@ -0,0 +1,364 @@
+/**
+ * @file rsa_public_key.c
+ * 
+ * @brief Implementation of rsa_public_key_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 <gmp.h>
+
+#include "rsa_public_key.h"
+
+#include <daemon.h>
+#include <utils/allocator.h>
+#include <transforms/hashers/hasher.h>
+
+/* since we don't have an ASN1 parser/generator,
+ * we use these predefined values for
+ * hash algorithm oids. These also contain
+ * the length of the following hash.
+ * These values are also used in rsa_private_key.c
+ */
+
+u_int8_t md2_oid[18] = {
+	0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,
+	0x48,0x86,0xf7,0x0d,0x02,0x02,0x05,0x00,
+	0x04,0x10
+};
+
+u_int8_t md5_oid[] = {
+	0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,
+	0x48,0x86,0xf7,0x0d,0x02,0x05,0x05,0x00,
+	0x04,0x10
+};
+
+u_int8_t sha1_oid[] = {
+	0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x0e,
+	0x03,0x02,0x1a,0x05,0x00,0x04,0x14
+};
+
+u_int8_t sha256_oid[] = {
+	0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,
+	0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,
+	0x00,0x04,0x20
+};
+
+u_int8_t sha384_oid[] = {
+	0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,
+	0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,
+	0x00,0x04,0x30
+};
+
+u_int8_t sha512_oid[] = {
+	0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,
+	0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,
+	0x00,0x04,0x40
+};
+
+
+typedef struct private_rsa_public_key_t private_rsa_public_key_t;
+
+/**
+ * private data structure with signing context.
+ */
+struct private_rsa_public_key_t {
+	/**
+	 * Public interface for this signer.
+	 */
+	rsa_public_key_t public;
+	
+	/**
+	 * is the key already set ?
+	 */
+	bool is_key_set;
+	
+	/**
+	 * public modulus
+	 */
+	mpz_t n;
+	/**
+	 * public exponent
+	 */
+	mpz_t e;
+	
+	/**
+	 * keysize in bytes
+	 */
+	size_t k;
+	
+	/**
+	 * @brief Implements the RSAEP algorithm specified in PKCS#1.
+	 */
+	chunk_t (*rsaep) (private_rsa_public_key_t *this, chunk_t data);
+		
+	/**
+	 * @brief Implements the RSASVP1 algorithm specified in PKCS#1.
+	 */
+	chunk_t (*rsavp1) (private_rsa_public_key_t *this, chunk_t data);
+};
+
+/**
+ * Implements private_rsa_public_key_t.rsadp
+ * Implements private_rsa_public_key_t.rsavp1
+ */
+static chunk_t rsaep(private_rsa_public_key_t *this, chunk_t data)
+{
+	mpz_t m, c;
+	chunk_t encrypted;
+	
+	mpz_init(c);
+	mpz_init(m);
+	
+	mpz_import(m, data.len, 1, 1, 1, 0, data.ptr);
+	
+	mpz_powm(c, m, this->e, this->n);
+
+    encrypted.len = this->k;
+    encrypted.ptr = mpz_export(NULL, NULL, 1, encrypted.len, 1, 0, c);
+	
+	mpz_clear(c);
+	mpz_clear(m);	
+	
+	return encrypted;
+}
+
+/**
+ * implementation of rsa_public_key.verify_emsa_signature.
+ */
+static status_t verify_emsa_pkcs1_signature(private_rsa_public_key_t *this, chunk_t data, chunk_t signature)
+{
+	hasher_t *hasher = NULL;
+	chunk_t hash;
+	chunk_t em;
+	u_int8_t *pos;
+	
+	if (signature.len > this->k)
+	{
+		return INVALID_ARG;	
+	}
+	
+	/* unpack signature */
+	em = this->rsavp1(this, signature);
+	
+	/* result should look like this:
+	 * EM = 0x00 || 0x01 || PS || 0x00 || T. 
+	 * PS = 0xFF padding, with length to fill em
+	 * T = oid || hash
+	 */	
+	
+	/* check magic bytes */
+	if ((*(em.ptr) != 0x00) ||
+		(*(em.ptr+1) != 0x01))
+	{
+		allocator_free(em.ptr);
+		return FAILED;
+	}
+	
+	/* find magic 0x00 */
+	pos = em.ptr + 2;
+	while (pos <= em.ptr + em.len)
+	{
+		if (*pos == 0x00)
+		{
+			/* found magic byte, stop */
+			pos++;
+			break;
+		}
+		else if (*pos != 0xFF)
+		{
+			/* bad padding, decryption failed ?!*/
+			allocator_free(em.ptr);
+			return FAILED;	
+		}
+		pos++;
+	}
+
+	if (pos + 20 > em.ptr + em.len)
+	{
+		/* not enought room for oid compare */
+		allocator_free(em.ptr);
+		return FAILED;	
+	}
+	
+	if (memcmp(md2_oid, pos, sizeof(md2_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_MD2);
+		pos += sizeof(md2_oid);
+	}
+	else if (memcmp(md5_oid, pos, sizeof(md5_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_MD5);
+		pos += sizeof(md5_oid);
+	}
+	else if (memcmp(sha1_oid, pos, sizeof(sha1_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA1);
+		pos += sizeof(sha1_oid);
+	}
+	else if (memcmp(sha256_oid, pos, sizeof(sha256_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA256);
+		pos += sizeof(sha256_oid);
+	}
+	else if (memcmp(sha384_oid, pos, sizeof(sha384_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA384);
+		pos += sizeof(sha384_oid);
+	}
+	else if (memcmp(sha512_oid, pos, sizeof(sha512_oid)) == 0)
+	{
+		hasher = hasher_create(HASH_SHA512);
+		pos += sizeof(sha512_oid);
+	}
+	
+	if (hasher == NULL)
+	{
+		/* not supported hash algorithm */
+		allocator_free(em.ptr);
+		return NOT_SUPPORTED;	
+	}
+	
+	if (pos + hasher->get_block_size(hasher) != em.ptr + em.len)
+	{
+		/* bad length */
+		allocator_free(em.ptr);
+		hasher->destroy(hasher);
+		return FAILED;	
+	}
+	
+	/* build own hash for a compare */
+	hasher->allocate_hash(hasher, data, &hash);
+	hasher->destroy(hasher);
+	
+	if (memcmp(hash.ptr, pos, hash.len) != 0)
+	{
+		/* hash does not equal */
+		allocator_free(hash.ptr);
+		allocator_free(em.ptr);
+		return FAILED;	
+			
+	}
+	
+	/* seems good */
+	allocator_free(hash.ptr);
+	allocator_free(em.ptr);
+	return SUCCESS;	
+}
+	
+/**
+ * implementation of rsa_public_key.set_key.
+ */
+static status_t set_key(private_rsa_public_key_t *this, chunk_t key)
+{
+	chunk_t n, e;
+	
+	n.len = key.len/2;
+	n.ptr = key.ptr;
+	e.len = n.len;
+	e.ptr = key.ptr + n.len;
+	
+	mpz_import(this->n, n.len, 1, 1, 1, 0, n.ptr);
+	mpz_import(this->e, n.len, 1, 1, 1, 0, e.ptr);
+	
+	this->k = n.len;
+	
+	this->is_key_set = TRUE;
+	
+	return SUCCESS;
+}	
+
+	
+/**
+ * implementation of rsa_public_key.get_key.
+ */
+static status_t get_key(private_rsa_public_key_t *this, chunk_t *key)
+{
+	if (!this->is_key_set)
+	{
+		return INVALID_STATE;	
+	}
+	
+	chunk_t n, e;
+
+	n.len = this->k;
+	n.ptr = mpz_export(NULL, NULL, 1, n.len, 1, 0, this->n);
+	e.len = this->k;
+	e.ptr = mpz_export(NULL, NULL, 1, e.len, 1, 0, this->e);
+	
+	key->len = this->k * 2;
+	key->ptr = allocator_alloc(key->len);
+	memcpy(key->ptr, n.ptr, n.len);
+	memcpy(key->ptr + n.len, e.ptr, e.len);
+	allocator_free(n.ptr);
+	allocator_free(e.ptr);
+	
+	return SUCCESS;
+}
+	
+/**
+ * implementation of rsa_public_key.load_key.
+ */
+static status_t load_key(private_rsa_public_key_t *this, char *file)
+{
+	return NOT_SUPPORTED;
+}
+
+/**
+ * implementation of rsa_public_key.save_key.
+ */
+static status_t save_key(private_rsa_public_key_t *this, char *file)
+{
+	return NOT_SUPPORTED;
+}
+
+/**
+ * implementation of rsa_public_key.destroy.
+ */
+static void destroy(private_rsa_public_key_t *this)
+{
+	if (this->is_key_set)
+	{
+		mpz_clear(this->n);
+		mpz_clear(this->e);
+	}
+	allocator_free(this);
+}
+
+/*
+ * Described in header
+ */
+rsa_public_key_t *rsa_public_key_create()
+{
+	private_rsa_public_key_t *this = allocator_alloc_thing(private_rsa_public_key_t);
+	
+	/* public functions */
+	this->public.verify_emsa_pkcs1_signature = (status_t (*) (rsa_public_key_t*,chunk_t,chunk_t))verify_emsa_pkcs1_signature;
+	this->public.set_key = (status_t (*) (rsa_public_key_t*,chunk_t))set_key;
+	this->public.get_key = (status_t (*) (rsa_public_key_t*,chunk_t*))get_key;
+	this->public.load_key = (status_t (*) (rsa_public_key_t*,char*))load_key;
+	this->public.save_key = (status_t (*) (rsa_public_key_t*,char*))save_key;
+	this->public.destroy = (void (*) (rsa_public_key_t*))destroy;
+	
+	/* private functions */
+	this->rsaep = rsaep;
+	this->rsavp1 = rsaep; /* same algorithm */
+	
+	this->is_key_set = FALSE;
+	
+	return &(this->public);
+}