merged the modularization branch (credentials) back to trunk
This commit is contained in:
Martin Willi
@@ -0,0 +1,574 @@
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/*
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* Copyright (C) 2005-2008 Martin Willi
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* Copyright (C) 2005 Jan Hutter
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* Hochschule fuer Technik Rapperswil
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*
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* This program is free software; you can redistribute it and/or modify it
|
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* 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
|
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* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
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*
|
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* $Id$
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*/
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#include <gmp.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <string.h>
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#include "gmp_rsa_public_key.h"
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#include <debug.h>
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#include <crypto/hashers/hasher.h>
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#include <asn1/asn1.h>
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#include <asn1/pem.h>
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/**
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* defined in gmp_rsa_private_key.c
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*/
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extern chunk_t gmp_mpz_to_asn1(const mpz_t value);
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/**
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* ASN.1 definition of a subjectPublicKeyInfo structure
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*/
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static const asn1Object_t pkinfoObjects[] = {
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{ 0, "subjectPublicKeyInfo",ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
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{ 1, "algorithm", ASN1_EOC, ASN1_RAW }, /* 1 */
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{ 1, "subjectPublicKey", ASN1_BIT_STRING, ASN1_NONE }, /* 2 */
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{ 2, "RSAPublicKey", ASN1_SEQUENCE, ASN1_RAW }, /* 3 */
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};
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#define PKINFO 0
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#define PKINFO_SUBJECT_PK_ALGORITHM 1
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#define PKINFO_SUBJECT_PK 2
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#define PKINFO_gmp_rsa_public_key 3
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#define PKINFO_ROOF 4
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/* ASN.1 definition of RSApublicKey */
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static const asn1Object_t pubkeyObjects[] = {
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{ 0, "RSAPublicKey", ASN1_SEQUENCE, ASN1_OBJ }, /* 0 */
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{ 1, "modulus", ASN1_INTEGER, ASN1_BODY }, /* 1 */
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{ 1, "publicExponent", ASN1_INTEGER, ASN1_BODY }, /* 2 */
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};
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#define PUB_KEY_gmp_rsa_public_key 0
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#define PUB_KEY_MODULUS 1
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#define PUB_KEY_EXPONENT 2
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#define PUB_KEY_ROOF 3
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/* ASN.1 definition of digestInfo */
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static const asn1Object_t digestInfoObjects[] = {
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{ 0, "digestInfo", ASN1_SEQUENCE, ASN1_OBJ }, /* 0 */
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{ 1, "digestAlgorithm", ASN1_EOC, ASN1_RAW }, /* 1 */
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{ 1, "digest", ASN1_OCTET_STRING, ASN1_BODY }, /* 2 */
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};
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#define DIGEST_INFO 0
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#define DIGEST_INFO_ALGORITHM 1
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#define DIGEST_INFO_DIGEST 2
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#define DIGEST_INFO_ROOF 3
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typedef struct private_gmp_rsa_public_key_t private_gmp_rsa_public_key_t;
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/**
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* Private data structure with signing context.
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*/
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struct private_gmp_rsa_public_key_t {
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/**
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* Public interface for this signer.
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*/
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gmp_rsa_public_key_t public;
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/**
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* Public modulus.
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*/
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mpz_t n;
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/**
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* Public exponent.
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*/
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mpz_t e;
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/**
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* Keysize in bytes.
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*/
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size_t k;
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/**
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* Keyid formed as a SHA-1 hash of a publicKeyInfo object
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*/
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identification_t *keyid_info;
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/**
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* Keyid formed as a SHA-1 hash of a publicKey object
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*/
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identification_t *keyid;
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/**
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* reference counter
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*/
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refcount_t ref;
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};
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/**
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* RSAEP algorithm specified in PKCS#1.
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*/
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static chunk_t rsaep(private_gmp_rsa_public_key_t *this, chunk_t data)
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{
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mpz_t m, c;
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chunk_t encrypted;
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mpz_init(c);
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mpz_init(m);
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mpz_import(m, data.len, 1, 1, 1, 0, data.ptr);
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mpz_powm(c, m, this->e, this->n);
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encrypted.len = this->k;
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encrypted.ptr = mpz_export(NULL, NULL, 1, encrypted.len, 1, 0, c);
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mpz_clear(c);
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mpz_clear(m);
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return encrypted;
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}
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/**
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* RSAVP1 algorithm specified in PKCS#1.
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*/
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static chunk_t rsavp1(private_gmp_rsa_public_key_t *this, chunk_t data)
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{
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return rsaep(this, data);
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}
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/**
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* Verification of an EMPSA PKCS1 signature described in PKCS#1
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*/
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static bool verify_emsa_pkcs1_signature(private_gmp_rsa_public_key_t *this,
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hash_algorithm_t algorithm,
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chunk_t data, chunk_t signature)
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{
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chunk_t em_ori, em;
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bool res = FALSE;
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/* remove any preceding 0-bytes from signature */
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while (signature.len && *(signature.ptr) == 0x00)
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{
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signature.len -= 1;
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signature.ptr++;
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}
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if (signature.len > this->k)
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{
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return INVALID_ARG;
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}
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/* unpack signature */
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em_ori = em = rsavp1(this, signature);
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/* result should look like this:
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* EM = 0x00 || 0x01 || PS || 0x00 || T.
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* PS = 0xFF padding, with length to fill em
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* T = oid || hash
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*/
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/* check magic bytes */
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if (*(em.ptr) != 0x00 || *(em.ptr+1) != 0x01)
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{
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goto end;
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}
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em.ptr += 2;
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em.len -= 2;
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/* find magic 0x00 */
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while (em.len > 0)
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{
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if (*em.ptr == 0x00)
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{
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/* found magic byte, stop */
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em.ptr++;
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em.len--;
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break;
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}
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else if (*em.ptr != 0xFF)
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{
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/* bad padding, decryption failed ?!*/
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goto end;
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}
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em.ptr++;
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em.len--;
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}
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if (em.len == 0)
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{
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/* no digestInfo found */
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goto end;
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}
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/* parse ASN.1-based digestInfo */
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{
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asn1_ctx_t ctx;
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chunk_t object;
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u_int level;
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int objectID = 0;
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hash_algorithm_t hash_algorithm = HASH_UNKNOWN;
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asn1_init(&ctx, em, 0, FALSE, FALSE);
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while (objectID < DIGEST_INFO_ROOF)
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{
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if (!extract_object(digestInfoObjects, &objectID, &object, &level, &ctx))
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{
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goto end;
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}
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switch (objectID)
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{
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case DIGEST_INFO:
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{
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if (em.len > object.len)
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{
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DBG1("digestInfo field in signature is followed by %u surplus bytes",
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em.len - object.len);
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goto end;
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}
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break;
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}
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case DIGEST_INFO_ALGORITHM:
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{
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int hash_oid = parse_algorithmIdentifier(object, level+1, NULL);
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hash_algorithm = hasher_algorithm_from_oid(hash_oid);
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if (hash_algorithm == HASH_UNKNOWN ||
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(algorithm != HASH_UNKNOWN && hash_algorithm != algorithm))
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{
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DBG1("wrong hash algorithm used in signature");
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goto end;
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}
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break;
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}
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case DIGEST_INFO_DIGEST:
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{
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chunk_t hash;
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hasher_t *hasher;
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hasher = lib->crypto->create_hasher(lib->crypto, hash_algorithm);
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if (hasher == NULL)
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{
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DBG1("hash algorithm %N not supported",
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hash_algorithm_names, hash_algorithm);
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goto end;
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}
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if (object.len != hasher->get_hash_size(hasher))
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{
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DBG1("hash size in signature is %u bytes instead of %u "
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"bytes", object.len, hasher->get_hash_size(hasher));
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hasher->destroy(hasher);
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goto end;
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}
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/* build our own hash and compare */
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hasher->allocate_hash(hasher, data, &hash);
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hasher->destroy(hasher);
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res = memeq(object.ptr, hash.ptr, hash.len);
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free(hash.ptr);
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break;
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}
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default:
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break;
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}
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objectID++;
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}
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}
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end:
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free(em_ori.ptr);
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return res;
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}
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/**
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* Implementation of public_key_t.get_type.
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*/
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static key_type_t get_type(private_gmp_rsa_public_key_t *this)
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{
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return KEY_RSA;
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}
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|
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/**
|
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* Implementation of public_key_t.verify.
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||||
*/
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static bool verify(private_gmp_rsa_public_key_t *this, signature_scheme_t scheme,
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chunk_t data, chunk_t signature)
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{
|
||||
switch (scheme)
|
||||
{
|
||||
case SIGN_DEFAULT: /* default is EMSA-PKCS1 using included OID */
|
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return verify_emsa_pkcs1_signature(this, HASH_UNKNOWN, data, signature);
|
||||
case SIGN_RSA_EMSA_PKCS1_MD5:
|
||||
return verify_emsa_pkcs1_signature(this, HASH_MD5, data, signature);
|
||||
case SIGN_RSA_EMSA_PKCS1_SHA1:
|
||||
return verify_emsa_pkcs1_signature(this, HASH_SHA1, data, signature);
|
||||
case SIGN_RSA_EMSA_PKCS1_SHA256:
|
||||
return verify_emsa_pkcs1_signature(this, HASH_SHA256, data, signature);
|
||||
case SIGN_RSA_EMSA_PKCS1_SHA384:
|
||||
return verify_emsa_pkcs1_signature(this, HASH_SHA384, data, signature);
|
||||
case SIGN_RSA_EMSA_PKCS1_SHA512:
|
||||
return verify_emsa_pkcs1_signature(this, HASH_SHA512, data, signature);
|
||||
default:
|
||||
DBG1("signature scheme %N not supported in RSA",
|
||||
signature_scheme_names, scheme);
|
||||
return FALSE;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Implementation of public_key_t.get_keysize.
|
||||
*/
|
||||
static bool encrypt(private_gmp_rsa_public_key_t *this, chunk_t crypto, chunk_t *plain)
|
||||
{
|
||||
DBG1("RSA public key encryption not implemented");
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
/**
|
||||
* Implementation of public_key_t.get_keysize.
|
||||
*/
|
||||
static size_t get_keysize(private_gmp_rsa_public_key_t *this)
|
||||
{
|
||||
return this->k;
|
||||
}
|
||||
|
||||
/**
|
||||
* Implementation of public_key_t.get_id.
|
||||
*/
|
||||
static identification_t *get_id(private_gmp_rsa_public_key_t *this,
|
||||
id_type_t type)
|
||||
{
|
||||
switch (type)
|
||||
{
|
||||
case ID_PUBKEY_INFO_SHA1:
|
||||
return this->keyid_info;
|
||||
case ID_PUBKEY_SHA1:
|
||||
return this->keyid;
|
||||
default:
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Implementation of public_key_t.get_encoding.
|
||||
*/
|
||||
static chunk_t get_encoding(private_gmp_rsa_public_key_t *this)
|
||||
{
|
||||
return asn1_wrap(ASN1_SEQUENCE, "mm",
|
||||
gmp_mpz_to_asn1(this->n),
|
||||
gmp_mpz_to_asn1(this->e));
|
||||
}
|
||||
|
||||
/**
|
||||
* Implementation of public_key_t.get_ref.
|
||||
*/
|
||||
static private_gmp_rsa_public_key_t* get_ref(private_gmp_rsa_public_key_t *this)
|
||||
{
|
||||
ref_get(&this->ref);
|
||||
return this;
|
||||
}
|
||||
|
||||
/**
|
||||
* Implementation of gmp_rsa_public_key.destroy.
|
||||
*/
|
||||
static void destroy(private_gmp_rsa_public_key_t *this)
|
||||
{
|
||||
if (ref_put(&this->ref))
|
||||
{
|
||||
mpz_clear(this->n);
|
||||
mpz_clear(this->e);
|
||||
DESTROY_IF(this->keyid);
|
||||
DESTROY_IF(this->keyid_info);
|
||||
free(this);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Generic private constructor
|
||||
*/
|
||||
static private_gmp_rsa_public_key_t *gmp_rsa_public_key_create_empty()
|
||||
{
|
||||
private_gmp_rsa_public_key_t *this = malloc_thing(private_gmp_rsa_public_key_t);
|
||||
|
||||
this->public.interface.get_type = (key_type_t (*)(public_key_t *this))get_type;
|
||||
this->public.interface.verify = (bool (*)(public_key_t *this, signature_scheme_t scheme, chunk_t data, chunk_t signature))verify;
|
||||
this->public.interface.encrypt = (bool (*)(public_key_t *this, chunk_t crypto, chunk_t *plain))encrypt;
|
||||
this->public.interface.get_keysize = (size_t (*) (public_key_t *this))get_keysize;
|
||||
this->public.interface.get_id = (identification_t* (*) (public_key_t *this,id_type_t))get_id;
|
||||
this->public.interface.get_encoding = (chunk_t(*)(public_key_t*))get_encoding;
|
||||
this->public.interface.get_ref = (public_key_t* (*)(public_key_t *this))get_ref;
|
||||
this->public.interface.destroy = (void (*)(public_key_t *this))destroy;
|
||||
|
||||
this->keyid = NULL;
|
||||
this->keyid_info = NULL;
|
||||
this->ref = 1;
|
||||
|
||||
return this;
|
||||
}
|
||||
|
||||
/**
|
||||
* Build the RSA key identifier from n and e using SHA1 hashed publicKey(Info).
|
||||
* Also used in rsa_private_key.c.
|
||||
*/
|
||||
bool gmp_rsa_public_key_build_id(mpz_t n, mpz_t e, identification_t **keyid,
|
||||
identification_t **keyid_info)
|
||||
{
|
||||
chunk_t publicKeyInfo, publicKey, hash;
|
||||
hasher_t *hasher;
|
||||
|
||||
hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
|
||||
if (hasher == NULL)
|
||||
{
|
||||
DBG1("SHA1 hash algorithm not supported, unable to use RSA");
|
||||
return FALSE;
|
||||
}
|
||||
publicKey = asn1_wrap(ASN1_SEQUENCE, "mm",
|
||||
gmp_mpz_to_asn1(n),
|
||||
gmp_mpz_to_asn1(e));
|
||||
hasher->allocate_hash(hasher, publicKey, &hash);
|
||||
*keyid = identification_create_from_encoding(ID_PUBKEY_SHA1, hash);
|
||||
chunk_free(&hash);
|
||||
|
||||
publicKeyInfo = asn1_wrap(ASN1_SEQUENCE, "cm",
|
||||
asn1_algorithmIdentifier(OID_RSA_ENCRYPTION),
|
||||
asn1_bitstring("m", publicKey));
|
||||
hasher->allocate_hash(hasher, publicKeyInfo, &hash);
|
||||
*keyid_info = identification_create_from_encoding(ID_PUBKEY_INFO_SHA1, hash);
|
||||
chunk_free(&hash);
|
||||
|
||||
hasher->destroy(hasher);
|
||||
chunk_free(&publicKeyInfo);
|
||||
|
||||
return TRUE;
|
||||
}
|
||||
|
||||
/**
|
||||
* Load a public key from an ASN1 encoded blob
|
||||
*/
|
||||
static gmp_rsa_public_key_t *load(chunk_t blob)
|
||||
{
|
||||
asn1_ctx_t ctx;
|
||||
chunk_t object;
|
||||
u_int level;
|
||||
int objectID = 0;
|
||||
private_gmp_rsa_public_key_t *this = gmp_rsa_public_key_create_empty();
|
||||
|
||||
mpz_init(this->n);
|
||||
mpz_init(this->e);
|
||||
|
||||
asn1_init(&ctx, blob, 0, FALSE, FALSE);
|
||||
|
||||
while (objectID < PUB_KEY_ROOF)
|
||||
{
|
||||
if (!extract_object(pubkeyObjects, &objectID, &object, &level, &ctx))
|
||||
{
|
||||
free(blob.ptr);
|
||||
destroy(this);
|
||||
return NULL;
|
||||
}
|
||||
switch (objectID)
|
||||
{
|
||||
case PUB_KEY_MODULUS:
|
||||
mpz_import(this->n, object.len, 1, 1, 1, 0, object.ptr);
|
||||
break;
|
||||
case PUB_KEY_EXPONENT:
|
||||
mpz_import(this->e, object.len, 1, 1, 1, 0, object.ptr);
|
||||
break;
|
||||
}
|
||||
objectID++;
|
||||
}
|
||||
free(blob.ptr);
|
||||
this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8;
|
||||
if (!gmp_rsa_public_key_build_id(this->n, this->e,
|
||||
&this->keyid, &this->keyid_info))
|
||||
{
|
||||
destroy(this);
|
||||
return NULL;
|
||||
}
|
||||
return &this->public;
|
||||
}
|
||||
|
||||
|
||||
typedef struct private_builder_t private_builder_t;
|
||||
/**
|
||||
* Builder implementation for key loading
|
||||
*/
|
||||
struct private_builder_t {
|
||||
/** implements the builder interface */
|
||||
builder_t public;
|
||||
/** loaded public key */
|
||||
gmp_rsa_public_key_t *key;
|
||||
};
|
||||
|
||||
/**
|
||||
* Implementation of builder_t.build
|
||||
*/
|
||||
static gmp_rsa_public_key_t *build(private_builder_t *this)
|
||||
{
|
||||
gmp_rsa_public_key_t *key = this->key;
|
||||
|
||||
free(this);
|
||||
return key;
|
||||
}
|
||||
|
||||
/**
|
||||
* Implementation of builder_t.add
|
||||
*/
|
||||
static void add(private_builder_t *this, builder_part_t part, ...)
|
||||
{
|
||||
va_list args;
|
||||
|
||||
if (this->key)
|
||||
{
|
||||
DBG1("ignoring surplus build part %N", builder_part_names, part);
|
||||
return;
|
||||
}
|
||||
|
||||
switch (part)
|
||||
{
|
||||
case BUILD_BLOB_ASN1_DER:
|
||||
{
|
||||
va_start(args, part);
|
||||
this->key = load(va_arg(args, chunk_t));
|
||||
va_end(args);
|
||||
break;
|
||||
}
|
||||
default:
|
||||
DBG1("ignoring unsupported build part %N", builder_part_names, part);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Builder construction function
|
||||
*/
|
||||
builder_t *gmp_rsa_public_key_builder(key_type_t type)
|
||||
{
|
||||
private_builder_t *this;
|
||||
|
||||
if (type != KEY_RSA)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
this = malloc_thing(private_builder_t);
|
||||
|
||||
this->key = NULL;
|
||||
this->public.add = (void(*)(builder_t *this, builder_part_t part, ...))add;
|
||||
this->public.build = (void*(*)(builder_t *this))build;
|
||||
|
||||
return &this->public;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user