DSA签名(摘要算法SHA256), DSA验签(摘要算法SHA256)
签名 : 用发送者的私钥进行签名.
验签 : 用发送者的公钥进行验签.
看下API调用顺序就行, 自己弄的时候, 跟着demo的流程弄就行.
对于openssl3.2, 越看越眼熟了.
/*!
\file EVP_DSA_Signature_demo.c
\note
openssl3.2 - 官方demo学习 - signature - EVP_DSA_Signature_demo.c
DSA签名(摘要算法SHA256), DSA验签(摘要算法SHA256)
签名 : 用发送者的私钥进行签名.
验签 : 用发送者的公钥进行验签.
看下API调用顺序就行, 自己弄的时候, 跟着demo的流程弄就行.
对于openssl3.2, 越看越眼熟了.
*/
/*-
* 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
*/
/*
* An example that uses the EVP_PKEY*, EVP_DigestSign* and EVP_DigestVerify*
* methods to calculate public/private DSA keypair and to sign and verify
* two static buffers.
*/
#include <string.h>
#include <stdio.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/decoder.h>
#include <openssl/dsa.h>
#include "my_openSSL_lib.h"
/*
* This demonstration will calculate and verify a signature of data using
* the soliloquy from Hamlet scene 1 act 3
*/
static const char *hamlet_1 =
"To be, or not to be, that is the question,\n"
"Whether tis nobler in the minde to suffer\n"
"The slings and arrowes of outragious fortune,\n"
"Or to take Armes again in a sea of troubles,\n"
;
static const char *hamlet_2 =
"And by opposing, end them, to die to sleep;\n"
"No more, and by a sleep, to say we end\n"
"The heart-ache, and the thousand natural shocks\n"
"That flesh is heir to? tis a consumation\n"
;
static const char ALG[] = "DSA";
static const char DIGEST[] = "SHA256";
static const int NUMBITS = 2048;
static const char * const PROPQUERY = NULL;
static int generate_dsa_params(OSSL_LIB_CTX *libctx,
EVP_PKEY **p_params)
{
int ret = 0;
EVP_PKEY_CTX *pkey_ctx = NULL;
EVP_PKEY *params = NULL;
pkey_ctx = EVP_PKEY_CTX_new_from_name(libctx, ALG, PROPQUERY);
if (pkey_ctx == NULL)
goto end;
if (EVP_PKEY_paramgen_init(pkey_ctx) <= 0)
goto end;
if (EVP_PKEY_CTX_set_dsa_paramgen_bits(pkey_ctx, NUMBITS) <= 0)
goto end;
if (EVP_PKEY_paramgen(pkey_ctx, ¶ms) <= 0)
goto end;
if (params == NULL)
goto end;
ret = 1;
end:
if(ret != 1) {
EVP_PKEY_free(params);
params = NULL;
}
EVP_PKEY_CTX_free(pkey_ctx);
*p_params = params;
fprintf(stdout, "Params:\n");
EVP_PKEY_print_params_fp(stdout, params, 4, NULL);
fprintf(stdout, "\n");
return ret;
}
static int generate_dsa_key(OSSL_LIB_CTX *libctx,
EVP_PKEY *params,
EVP_PKEY **p_pkey)
{
int ret = 0;
EVP_PKEY_CTX *ctx = NULL;
EVP_PKEY *pkey = NULL;
ctx = EVP_PKEY_CTX_new_from_pkey(libctx, params,
NULL);
if (ctx == NULL)
goto end;
if (EVP_PKEY_keygen_init(ctx) <= 0)
goto end;
if (EVP_PKEY_keygen(ctx, &pkey) <= 0)
goto end;
if (pkey == NULL)
goto end;
ret = 1;
end:
if(ret != 1) {
EVP_PKEY_free(pkey);
pkey = NULL;
}
EVP_PKEY_CTX_free(ctx);
*p_pkey = pkey;
fprintf(stdout, "Generating public/private key pair:\n");
EVP_PKEY_print_public_fp(stdout, pkey, 4, NULL);
fprintf(stdout, "\n");
EVP_PKEY_print_private_fp(stdout, pkey, 4, NULL);
fprintf(stdout, "\n");
EVP_PKEY_print_params_fp(stdout, pkey, 4, NULL);
fprintf(stdout, "\n");
return ret;
}
static int extract_public_key(const EVP_PKEY *pkey,
OSSL_PARAM **p_public_key)
{
int ret = 0;
OSSL_PARAM *public_key = NULL;
if (EVP_PKEY_todata(pkey, EVP_PKEY_PUBLIC_KEY, &public_key) != 1)
goto end;
ret = 1;
end:
if (ret != 1) {
OSSL_PARAM_free(public_key);
public_key = NULL;
}
*p_public_key = public_key;
return ret;
}
static int extract_keypair(const EVP_PKEY *pkey,
OSSL_PARAM **p_keypair)
{
int ret = 0;
OSSL_PARAM *keypair = NULL;
if (EVP_PKEY_todata(pkey, EVP_PKEY_KEYPAIR, &keypair) != 1)
goto end;
ret = 1;
end:
if (ret != 1) {
OSSL_PARAM_free(keypair);
keypair = NULL;
}
*p_keypair = keypair;
return ret;
}
static int demo_sign(OSSL_LIB_CTX *libctx,
size_t *p_sig_len, unsigned char **p_sig_value,
OSSL_PARAM keypair[])
{
int ret = 0;
size_t sig_len = 0;
unsigned char *sig_value = NULL;
EVP_MD_CTX *ctx = NULL;
EVP_PKEY_CTX *pkey_ctx = NULL;
EVP_PKEY *pkey = NULL;
pkey_ctx = EVP_PKEY_CTX_new_from_name(libctx, ALG, PROPQUERY);
if (pkey_ctx == NULL)
goto end;
if (EVP_PKEY_fromdata_init(pkey_ctx) != 1)
goto end;
if (EVP_PKEY_fromdata(pkey_ctx, &pkey, EVP_PKEY_KEYPAIR, keypair) != 1)
goto end;
ctx = EVP_MD_CTX_create();
if (ctx == NULL)
goto end;
if (EVP_DigestSignInit_ex(ctx, NULL, DIGEST, libctx, NULL, pkey, NULL) != 1)
goto end;
if (EVP_DigestSignUpdate(ctx, hamlet_1, sizeof(hamlet_1)) != 1)
goto end;
if (EVP_DigestSignUpdate(ctx, hamlet_2, sizeof(hamlet_2)) != 1)
goto end;
/* Calculate the signature size */
if (EVP_DigestSignFinal(ctx, NULL, &sig_len) != 1)
goto end;
if (sig_len == 0)
goto end;
sig_value = OPENSSL_malloc(sig_len);
if (sig_value == NULL)
goto end;
/* Calculate the signature */
if (EVP_DigestSignFinal(ctx, sig_value, &sig_len) != 1)
goto end;
ret = 1;
end:
EVP_MD_CTX_free(ctx);
if (ret != 1) {
OPENSSL_free(sig_value);
sig_len = 0;
sig_value = NULL;
}
*p_sig_len = sig_len;
*p_sig_value = sig_value;
EVP_PKEY_free(pkey);
EVP_PKEY_CTX_free(pkey_ctx);
fprintf(stdout, "Generating signature:\n");
BIO_dump_indent_fp(stdout, sig_value, (int)sig_len, 2);
fprintf(stdout, "\n");
return ret;
}
static int demo_verify(OSSL_LIB_CTX *libctx,
size_t sig_len, unsigned char *sig_value,
OSSL_PARAM public_key[])
{
int ret = 0;
EVP_MD_CTX *ctx = NULL;
EVP_PKEY_CTX *pkey_ctx = NULL;
EVP_PKEY *pkey = NULL;
pkey_ctx = EVP_PKEY_CTX_new_from_name(libctx, ALG, PROPQUERY);
if (pkey_ctx == NULL)
goto end;
if (EVP_PKEY_fromdata_init(pkey_ctx) != 1)
goto end;
if (EVP_PKEY_fromdata(pkey_ctx, &pkey, EVP_PKEY_PUBLIC_KEY, public_key) != 1)
goto end;
ctx = EVP_MD_CTX_create();
if(ctx == NULL)
goto end;
if (EVP_DigestVerifyInit_ex(ctx, NULL, DIGEST, libctx, NULL, pkey, NULL) != 1)
goto end;
if (EVP_DigestVerifyUpdate(ctx, hamlet_1, sizeof(hamlet_1)) != 1)
goto end;
if (EVP_DigestVerifyUpdate(ctx, hamlet_2, sizeof(hamlet_2)) != 1)
goto end;
if (EVP_DigestVerifyFinal(ctx, sig_value, sig_len) != 1)
goto end;
ret = 1;
end:
EVP_PKEY_free(pkey);
EVP_PKEY_CTX_free(pkey_ctx);
EVP_MD_CTX_free(ctx);
return ret;
}
int main(void)
{
int ret = EXIT_FAILURE;
OSSL_LIB_CTX *libctx = NULL;
EVP_PKEY *params = NULL;
EVP_PKEY *pkey = NULL;
OSSL_PARAM *public_key = NULL;
OSSL_PARAM *keypair = NULL;
size_t sig_len = 0;
unsigned char *sig_value = NULL;
libctx = OSSL_LIB_CTX_new();
if (libctx == NULL)
goto end;
if (generate_dsa_params(libctx, ¶ms) != 1)
goto end;
if (generate_dsa_key(libctx, params, &pkey) != 1)
goto end;
if (extract_public_key(pkey, &public_key) != 1)
goto end;
if (extract_keypair(pkey, &keypair) != 1)
goto end;
/* The signer signs with his private key, and distributes his public key */
if (demo_sign(libctx, &sig_len, &sig_value, keypair) != 1)
goto end;
/* A verifier uses the signers public key to verify the signature */
if (demo_verify(libctx, sig_len, sig_value, public_key) != 1)
goto end;
ret = EXIT_SUCCESS;
end:
if (ret != EXIT_SUCCESS)
ERR_print_errors_fp(stderr);
OPENSSL_free(sig_value);
EVP_PKEY_free(params);
EVP_PKEY_free(pkey);
OSSL_PARAM_free(public_key);
OSSL_PARAM_free(keypair);
OSSL_LIB_CTX_free(libctx);
return ret;
}