GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libcrypto/rsa/rsa_pss.c Lines: 0 109 0.0 %
Date: 2017-11-07 Branches: 0 90 0.0 %

Line Branch Exec Source
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/* $OpenBSD: rsa_pss.c,v 1.12 2017/01/29 17:49:23 beck Exp $ */
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/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
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 * project 2005.
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 */
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/* ====================================================================
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 * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 *
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in
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 *    the documentation and/or other materials provided with the
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 *    distribution.
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 *
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 * 3. All advertising materials mentioning features or use of this
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 *    software must display the following acknowledgment:
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 *    "This product includes software developed by the OpenSSL Project
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 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
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 *
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 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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 *    endorse or promote products derived from this software without
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 *    prior written permission. For written permission, please contact
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 *    licensing@OpenSSL.org.
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 *
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 * 5. Products derived from this software may not be called "OpenSSL"
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 *    nor may "OpenSSL" appear in their names without prior written
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 *    permission of the OpenSSL Project.
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 *
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 * 6. Redistributions of any form whatsoever must retain the following
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 *    acknowledgment:
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 *    "This product includes software developed by the OpenSSL Project
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 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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 * OF THE POSSIBILITY OF SUCH DAMAGE.
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 * ====================================================================
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 *
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 * This product includes cryptographic software written by Eric Young
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 * (eay@cryptsoft.com).  This product includes software written by Tim
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 * Hudson (tjh@cryptsoft.com).
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 *
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <openssl/bn.h>
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#include <openssl/err.h>
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#include <openssl/evp.h>
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#include <openssl/rsa.h>
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#include <openssl/sha.h>
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static const unsigned char zeroes[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
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int
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RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash, const EVP_MD *Hash,
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    const unsigned char *EM, int sLen)
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{
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	return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen);
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}
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int
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RSA_verify_PKCS1_PSS_mgf1(RSA *rsa, const unsigned char *mHash,
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    const EVP_MD *Hash, const EVP_MD *mgf1Hash, const unsigned char *EM,
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    int sLen)
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{
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	int i;
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	int ret = 0;
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	int hLen, maskedDBLen, MSBits, emLen;
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	const unsigned char *H;
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	unsigned char *DB = NULL;
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	EVP_MD_CTX ctx;
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	unsigned char H_[EVP_MAX_MD_SIZE];
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	EVP_MD_CTX_init(&ctx);
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	if (mgf1Hash == NULL)
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		mgf1Hash = Hash;
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	hLen = EVP_MD_size(Hash);
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	if (hLen < 0)
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		goto err;
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	/*
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	 * Negative sLen has special meanings:
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	 *	-1	sLen == hLen
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	 *	-2	salt length is autorecovered from signature
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	 *	-N	reserved
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	 */
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	if (sLen == -1)
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		sLen = hLen;
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	else if (sLen == -2)
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		sLen = -2;
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	else if (sLen < -2) {
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		RSAerror(RSA_R_SLEN_CHECK_FAILED);
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		goto err;
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	}
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	MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
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	emLen = RSA_size(rsa);
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	if (EM[0] & (0xFF << MSBits)) {
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		RSAerror(RSA_R_FIRST_OCTET_INVALID);
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		goto err;
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	}
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	if (MSBits == 0) {
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		EM++;
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		emLen--;
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	}
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	if (emLen < (hLen + sLen + 2)) {
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		/* sLen can be small negative */
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		RSAerror(RSA_R_DATA_TOO_LARGE);
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		goto err;
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	}
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	if (EM[emLen - 1] != 0xbc) {
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		RSAerror(RSA_R_LAST_OCTET_INVALID);
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		goto err;
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	}
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	maskedDBLen = emLen - hLen - 1;
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	H = EM + maskedDBLen;
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	DB = malloc(maskedDBLen);
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	if (!DB) {
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		RSAerror(ERR_R_MALLOC_FAILURE);
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		goto err;
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	}
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	if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, mgf1Hash) < 0)
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		goto err;
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	for (i = 0; i < maskedDBLen; i++)
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		DB[i] ^= EM[i];
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	if (MSBits)
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		DB[0] &= 0xFF >> (8 - MSBits);
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	for (i = 0; DB[i] == 0 && i < (maskedDBLen - 1); i++)
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		;
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	if (DB[i++] != 0x1) {
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		RSAerror(RSA_R_SLEN_RECOVERY_FAILED);
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		goto err;
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	}
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	if (sLen >= 0 && (maskedDBLen - i) != sLen) {
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		RSAerror(RSA_R_SLEN_CHECK_FAILED);
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		goto err;
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	}
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	if (!EVP_DigestInit_ex(&ctx, Hash, NULL) ||
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	    !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) ||
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	    !EVP_DigestUpdate(&ctx, mHash, hLen))
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		goto err;
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	if (maskedDBLen - i) {
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		if (!EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i))
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			goto err;
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	}
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	if (!EVP_DigestFinal_ex(&ctx, H_, NULL))
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		goto err;
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	if (memcmp(H_, H, hLen)) {
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		RSAerror(RSA_R_BAD_SIGNATURE);
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		ret = 0;
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	} else
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		ret = 1;
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err:
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	free(DB);
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	EVP_MD_CTX_cleanup(&ctx);
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	return ret;
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}
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int
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RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
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    const unsigned char *mHash, const EVP_MD *Hash, int sLen)
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{
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	return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen);
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}
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int
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RSA_padding_add_PKCS1_PSS_mgf1(RSA *rsa, unsigned char *EM,
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    const unsigned char *mHash, const EVP_MD *Hash, const EVP_MD *mgf1Hash,
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    int sLen)
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{
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	int i;
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	int ret = 0;
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	int hLen, maskedDBLen, MSBits, emLen;
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	unsigned char *H, *salt = NULL, *p;
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	EVP_MD_CTX ctx;
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	EVP_MD_CTX_init(&ctx);
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	if (mgf1Hash == NULL)
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		mgf1Hash = Hash;
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	hLen = EVP_MD_size(Hash);
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	if (hLen < 0)
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		goto err;
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	/*
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	 * Negative sLen has special meanings:
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	 *	-1	sLen == hLen
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	 *	-2	salt length is maximized
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	 *	-N	reserved
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	 */
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	if (sLen == -1)
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		sLen = hLen;
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	else if (sLen == -2)
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		sLen = -2;
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	else if (sLen < -2) {
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		RSAerror(RSA_R_SLEN_CHECK_FAILED);
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		goto err;
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	}
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	MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
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	emLen = RSA_size(rsa);
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	if (MSBits == 0) {
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		*EM++ = 0;
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		emLen--;
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	}
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	if (sLen == -2)
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		sLen = emLen - hLen - 2;
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	else if (emLen < (hLen + sLen + 2)) {
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		RSAerror(RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
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		goto err;
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	}
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	if (sLen > 0) {
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		salt = malloc(sLen);
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		if (!salt) {
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			RSAerror(ERR_R_MALLOC_FAILURE);
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			goto err;
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		}
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		arc4random_buf(salt, sLen);
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	}
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	maskedDBLen = emLen - hLen - 1;
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	H = EM + maskedDBLen;
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	if (!EVP_DigestInit_ex(&ctx, Hash, NULL) ||
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	    !EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes) ||
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	    !EVP_DigestUpdate(&ctx, mHash, hLen))
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		goto err;
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	if (sLen && !EVP_DigestUpdate(&ctx, salt, sLen))
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		goto err;
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	if (!EVP_DigestFinal_ex(&ctx, H, NULL))
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		goto err;
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	/* Generate dbMask in place then perform XOR on it */
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	if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, mgf1Hash))
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		goto err;
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	p = EM;
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	/*
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	 * Initial PS XORs with all zeroes which is a NOP so just update
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	 * pointer. Note from a test above this value is guaranteed to
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	 * be non-negative.
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	 */
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	p += emLen - sLen - hLen - 2;
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	*p++ ^= 0x1;
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	if (sLen > 0) {
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		for (i = 0; i < sLen; i++)
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			*p++ ^= salt[i];
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	}
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	if (MSBits)
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		EM[0] &= 0xFF >> (8 - MSBits);
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	/* H is already in place so just set final 0xbc */
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	EM[emLen - 1] = 0xbc;
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	ret = 1;
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err:
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	free(salt);
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	EVP_MD_CTX_cleanup(&ctx);
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	return ret;
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}