openssl3.2 - 官方demo学习 - signature - rsa

文章目录

openssl3.2 - 官方demo学习 - signature - rsa_pss_direct.c概述笔记END

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

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