153 lines
4.3 KiB
C
153 lines
4.3 KiB
C
/* rsa-pss.c
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*
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* Copyright (C) 2006-2018 wolfSSL Inc.
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*
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* This file is part of wolfSSL.
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*
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* wolfSSL is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* wolfSSL is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
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*/
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/*
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* An implementation of RSA PSS digital signature using wolfSSL
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*/
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#include <stdio.h>
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#include <string.h>
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#include <wolfssl/options.h>
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#include <wolfssl/wolfcrypt/settings.h>
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#include <wolfssl/ssl.h>
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#include <wolfssl/wolfcrypt/rsa.h>
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static const char* kRsaPubKey = "./rsa-public.key";
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#define MAX_DER_SIZE 2048
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#define RSA_KEY_SIZE 2048
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int main(int argc, char** argv)
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{
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RsaKey* pRsaKey = NULL;
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WC_RNG rng;
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const char* szMessage = "This is the string to be signed";
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unsigned char pSignature[RSA_KEY_SIZE/8];
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unsigned char pDecrypted[RSA_KEY_SIZE/8];
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int status = 0;
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int sz;
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word32 idx = 0;
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unsigned char derBuf[MAX_DER_SIZE];
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pRsaKey = malloc(sizeof(RsaKey));
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wolfSSL_Debugging_ON();
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wolfSSL_Init();
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wc_InitRsaKey(pRsaKey, NULL);
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wc_InitRng(&rng);
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wc_RsaSetRNG(pRsaKey, &rng);
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if (memcmp(argv[1], "-o", 2) == 0) {
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printf("generating RSA key to make a PSS signature\n");
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/* Generate an RSA key pair */
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if (wc_MakeRsaKey(pRsaKey, RSA_KEY_SIZE, 0x010001, &rng) != 0) {
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printf("failed to create rsa key\n");
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}
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if (pRsaKey)
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{
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FILE* f;
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f = fopen(kRsaPubKey, "wb");
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printf("writing public key to %s\n", kRsaPubKey);
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if (f == NULL) {
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printf("unable to write out private key\n");
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}
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else {
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sz = wc_RsaKeyToDer(pRsaKey, derBuf, sizeof(derBuf));
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if (sz <= 0) {
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printf("error with rsa load der %d\n", sz);
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}
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fwrite(derBuf, 1, sz, f);
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fclose(f);
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}
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}
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}
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else {
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printf("reading in RSA key to verify signature\n");
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sz = wolfSSL_PemPubKeyToDer(kRsaPubKey, derBuf, sizeof(derBuf));
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wc_RsaPublicKeyDecode(derBuf, &idx, pRsaKey, sz);
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}
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if (!pRsaKey)
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{
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printf("RSA_generate_key failed with error\n");
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goto prog_end;
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}
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if (memcmp(argv[1], "-o", 2) == 0) {
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FILE* f = fopen(argv[2], "wb");
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printf("Creating PSS signature and writing to %s\n", argv[2]);
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if (f == NULL) {
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printf("error opening output file %s\n", argv[2]);
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goto prog_end;
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}
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/* perform digital signature */
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status = wc_RsaPSS_Sign((byte*)szMessage, sizeof(szMessage),
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pSignature, sizeof(pSignature),
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WC_HASH_TYPE_SHA256, WC_MGF1SHA256, pRsaKey, &rng);
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if (status <= 0)
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{
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printf("RSA_private_encrypt failed with error %d\n", status);
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goto prog_end;
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}
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fwrite(pSignature, 1, status, f);
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fclose(f);
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}
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else {
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FILE* f;
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f = fopen(argv[2], "rb");
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if (f == NULL) {
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printf("unable to open %s\n", argv[2]);
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goto prog_end;
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}
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fread(pSignature, 1, sizeof(pSignature), f);
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fclose(f);
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/* now we will verify the signature
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Start by a RAW decrypt of the signature
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*/
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byte* pt = pDecrypted;
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status = wc_RsaPSS_VerifyInline(pSignature, sizeof(pSignature), &pt,
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WC_HASH_TYPE_SHA256, WC_MGF1SHA256, pRsaKey);
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if (status <= 0)
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{
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printf("RSA_public_decrypt failed with error %d\n", status);
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goto prog_end;
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}
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else
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{
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printf("RSA PSS verify success\n");
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}
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}
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prog_end:
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if (pRsaKey)
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free(pRsaKey);
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wolfSSL_Cleanup();
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return 0;
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}
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