openssl3.2 - 官方demo学习 - signature - rsa_pss_direct.c

openssl3.2 - 官方demo学习 - signature - rsa_pss_direct.c

概述

用RSA私钥签名
d2i_PrivateKey_ex()可以从内存载入私钥数据, 得到私钥EVP_PKEY*
从私钥产生ctx, 对ctx进行签名初始化, 设置ctx的padding填充模式
摘要算法选用SHA256, 对ctx设置摘要算法
尝试签名, 得到签名长度, 然后进行私钥签名, 得到私钥签名buffer.

用RSA公钥验签
d2i_PublicKey()可以从内存载入公钥数据, 得到公钥EVP_PKEY*
验签时使用的摘要算法要和签名时一样.
验签初始化, 对ctx进行验签初始化, 这是ctx的padding填充模式(要和签名时一样)
进行验签

笔记

/*!
\file rsa_pss_direct.c
\note

openssl3.2 - 官方demo学习 - signature - rsa_pss_direct.c

用RSA私钥签名
d2i_PrivateKey_ex()可以从内存载入私钥数据, 得到私钥EVP_PKEY*
从私钥产生ctx, 对ctx进行签名初始化, 设置ctx的padding填充模式
摘要算法选用SHA256, 对ctx设置摘要算法
尝试签名, 得到签名长度, 然后进行私钥签名, 得到私钥签名buffer.


用RSA公钥验签
d2i_PublicKey()可以从内存载入公钥数据, 得到公钥EVP_PKEY*
验签时使用的摘要算法要和签名时一样.
验签初始化, 对ctx进行验签初始化, 这是ctx的padding填充模式(要和签名时一样)
进行验签

*/

/*
 * Copyright 2022-2023 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "rsa_pss.h"

#include "my_openSSL_lib.h"

 /*
  * The digest to be signed. This should be the output of a hash function.
  * Here we sign an all-zeroes digest for demonstration purposes.
  */
static const unsigned char test_digest[32] = { 0 };

/* A property query used for selecting algorithm implementations. */
static const char* propq = NULL;

/*
 * This function demonstrates RSA signing of a SHA-256 digest using the PSS
 * padding scheme. You must already have hashed the data you want to sign.
 * For a higher-level demonstration which does the hashing for you, see
 * rsa_pss_hash.c.
 *
 * For more information, see RFC 8017 section 9.1. The digest passed in
 * (test_digest above) corresponds to the 'mHash' value.
 */
static int sign(OSSL_LIB_CTX* libctx, unsigned char** sig, size_t* sig_len)
{
	int ret = 0;
	EVP_PKEY* pkey = NULL;
	EVP_PKEY_CTX* ctx = NULL;
	EVP_MD* md = NULL;
	const unsigned char* ppriv_key = NULL;

	*sig = NULL;

	/* Load DER-encoded RSA private key. */
	ppriv_key = rsa_priv_key;
	pkey = d2i_PrivateKey_ex(EVP_PKEY_RSA, NULL, &ppriv_key,
		sizeof(rsa_priv_key), libctx, propq);
	if (pkey == NULL) {
		fprintf(stderr, "Failed to load private key\n");
		goto end;
	}

	/* Fetch hash algorithm we want to use. */
	md = EVP_MD_fetch(libctx, "SHA256", propq);
	if (md == NULL) {
		fprintf(stderr, "Failed to fetch hash algorithm\n");
		goto end;
	}

	/* Create signing context. */
	ctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey, propq);
	if (ctx == NULL) {
		fprintf(stderr, "Failed to create signing context\n");
		goto end;
	}

	/* Initialize context for signing and set options. */
	if (EVP_PKEY_sign_init(ctx) == 0) {
		fprintf(stderr, "Failed to initialize signing context\n");
		goto end;
	}

	if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PSS_PADDING) == 0) {
		fprintf(stderr, "Failed to configure padding\n");
		goto end;
	}

	if (EVP_PKEY_CTX_set_signature_md(ctx, md) == 0) {
		fprintf(stderr, "Failed to configure digest type\n");
		goto end;
	}

	/* Determine length of signature. */
	if (EVP_PKEY_sign(ctx, NULL, sig_len,
		test_digest, sizeof(test_digest)) == 0) {
		fprintf(stderr, "Failed to get signature length\n");
		goto end;
	}

	/* Allocate memory for signature. */
	*sig = OPENSSL_malloc(*sig_len);
	if (*sig == NULL) {
		fprintf(stderr, "Failed to allocate memory for signature\n");
		goto end;
	}

	/* Generate signature. */
	if (EVP_PKEY_sign(ctx, *sig, sig_len,
		test_digest, sizeof(test_digest)) != 1) {
		fprintf(stderr, "Failed to sign\n");
		goto end;
	}

	ret = 1;
end:
	EVP_PKEY_CTX_free(ctx);
	EVP_PKEY_free(pkey);
	EVP_MD_free(md);

	if (ret == 0)
		OPENSSL_free(*sig);

	return ret;
}

/*
 * This function demonstrates verification of an RSA signature over a SHA-256
 * digest using the PSS signature scheme.
 */
static int verify(OSSL_LIB_CTX* libctx, const unsigned char* sig, size_t sig_len)
{
	int ret = 0;
	const unsigned char* ppub_key = NULL;
	EVP_PKEY* pkey = NULL;
	EVP_PKEY_CTX* ctx = NULL;
	EVP_MD* md = NULL;

	/* Load DER-encoded RSA public key. */
	ppub_key = rsa_pub_key;
	pkey = d2i_PublicKey(EVP_PKEY_RSA, NULL, &ppub_key, sizeof(rsa_pub_key));
	if (pkey == NULL) {
		fprintf(stderr, "Failed to load public key\n");
		goto end;
	}

	/* Fetch hash algorithm we want to use. */
	md = EVP_MD_fetch(libctx, "SHA256", propq);
	if (md == NULL) {
		fprintf(stderr, "Failed to fetch hash algorithm\n");
		goto end;
	}

	/* Create verification context. */
	ctx = EVP_PKEY_CTX_new_from_pkey(libctx, pkey, propq);
	if (ctx == NULL) {
		fprintf(stderr, "Failed to create verification context\n");
		goto end;
	}

	/* Initialize context for verification and set options. */
	if (EVP_PKEY_verify_init(ctx) == 0) {
		fprintf(stderr, "Failed to initialize verification context\n");
		goto end;
	}

	if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PSS_PADDING) == 0) {
		fprintf(stderr, "Failed to configure padding\n");
		goto end;
	}

	if (EVP_PKEY_CTX_set_signature_md(ctx, md) == 0) {
		fprintf(stderr, "Failed to configure digest type\n");
		goto end;
	}

	/* Verify signature. */
	if (EVP_PKEY_verify(ctx, sig, sig_len,
		test_digest, sizeof(test_digest)) == 0) {
		fprintf(stderr, "Failed to verify signature; "
			"signature may be invalid\n");
		goto end;
	}

	ret = 1;
end:
	EVP_PKEY_CTX_free(ctx);
	EVP_PKEY_free(pkey);
	EVP_MD_free(md);
	return ret;
}

int main(int argc, char** argv)
{
	int ret = EXIT_FAILURE;
	OSSL_LIB_CTX* libctx = NULL;
	unsigned char* sig = NULL;
	size_t sig_len = 0;

	if (sign(libctx, &sig, &sig_len) == 0)
		goto end;

	if (verify(libctx, sig, sig_len) == 0)
		goto end;

	ret = EXIT_SUCCESS;
end:
	OPENSSL_free(sig);
	OSSL_LIB_CTX_free(libctx);
	return ret;
}

END