318 lines
7.9 KiB
C
318 lines
7.9 KiB
C
/*-
|
|
* 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>
|
|
|
|
/*
|
|
* 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, 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;
|
|
}
|