wolfssl-examples/certgen/certgen_example.c

287 lines
9.5 KiB
C

/* certgen_example.c
*
* Copyright (C) 2006-2021 wolfSSL Inc.
*
* This file is part of wolfSSL.
*
* wolfSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* wolfSSL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
*/
#include <stdio.h>
#include <wolfssl/options.h>
#include <wolfssl/wolfcrypt/settings.h>
#include <wolfssl/wolfcrypt/ecc.h>
#include <wolfssl/wolfcrypt/asn_public.h>
#include <wolfssl/wolfcrypt/asn.h>
#include <wolfssl/wolfcrypt/error-crypt.h>
#if defined(WOLFSSL_CERT_REQ) && defined(WOLFSSL_CERT_GEN) && \
defined(WOLFSSL_KEY_GEN) && defined(HAVE_ECC)
#define HEAP_HINT NULL
#define LARGE_TEMP_SZ 4096
static int do_certgen(int argc, char** argv)
{
int ret = 0;
Cert newCert;
FILE* file;
char certToUse[] = "./ca-ecc-cert.der";
char caKeyFile[] = "./ca-ecc-key.der";
char newCertOutput[] = "./newCert.der";
int derBufSz;
int caKeySz;
byte* derBuf = NULL;
byte* pemBuf = NULL;
byte* caKeyBuf = NULL;
/* for MakeCert and SignCert */
WC_RNG rng;
ecc_key caKey;
ecc_key newKey;
word32 idx = 0;
int initRng = 0, initCaKey = 0, initNewKey = 0;
#ifdef WOLFSSL_DER_TO_PEM
char pemOutput[] = "./newCert.pem";
int pemBufSz;
#endif
#ifdef WOLFSSL_ALT_NAMES
/* Add some alt names to our cert: */
const char myAltNames[] = {
/* SEQUENCE (1 element with 3 segments. Entire length is 41
* (0x29 in hex))
*/
0x30, 0x29,
/* This is a String 0x8, it denotes a DNSName 0x2 -> 0x82
* This strings' length is 9 (0x09)
*/
0x82, 0x09,
/* This strings value is "localhost" (in hex) */
0x6C, 0x6F, 0x63, 0x61, 0x6C, 0x68, 0x6F, 0x73, 0x74,
/* This is a String 0x8, it denotes a DNSName 0x2 -> 0x82
* This strings' length is 11 (0x0B)
*/
0x82, 0x0B,
/* This strings value is "example.com" (in hex) */
0x65, 0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x2e, 0x63, 0x6f, 0x6d,
/* This is a String 0x8, it denotes a DNSName 0x2 -> 0x82
* This strings' length is 9 (0x09)
*/
0x82, 0x09,
/* This strings value is "127.0.0.1" (in hex) */
0x31, 0x32, 0x37, 0x2e, 0x30, 0x2e, 0x30, 0x2e, 0x31,
/* This is a string 0x08, it denotes an IP Address 0x07 -> 0x87 */
/* This strings length is 4 (0x04) */
0x87, 0x04,
/* The IP address is 127 (0x7F), 0 (0x00), 0, (0x00), 1 (0x01) ->
* 127.0.0.1
*/
0x7F, 0x00, 0x00, 0x01
};
#endif
/*------------------------------------------------------------------------*/
/* open the CA der formatted certificate, we need to get it's subject line
* to use in the new cert we're creating as the "Issuer" line */
/*------------------------------------------------------------------------*/
printf("Loading CA certificate\n");
derBuf = (byte*)XMALLOC(LARGE_TEMP_SZ, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER);
if (derBuf == NULL) goto exit;
XMEMSET(derBuf, 0, LARGE_TEMP_SZ);
file = fopen(certToUse, "rb");
if (!file) {
printf("failed to open file: %s\n", certToUse);
goto exit;
}
derBufSz = fread(derBuf, 1, LARGE_TEMP_SZ, file);
fclose(file);
printf("Successfully read %d bytes from %s\n\n", derBufSz, certToUse);
/*------------------------------------------------------------------------*/
/* open caKey file and get the caKey, we need it to sign our new cert */
/*------------------------------------------------------------------------*/
printf("Loading the CA key\n");
caKeyBuf = (byte*)XMALLOC(LARGE_TEMP_SZ, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER);
if (caKeyBuf == NULL) goto exit;
XMEMSET(caKeyBuf, 0, LARGE_TEMP_SZ);
file = fopen(caKeyFile, "rb");
if (!file) {
printf("failed to open file: %s\n", caKeyFile);
goto exit;
}
caKeySz = fread(caKeyBuf, 1, LARGE_TEMP_SZ, file);
fclose(file);
if (caKeySz <= 0) {
printf("Failed to read caKey from file\n");
goto exit;
}
printf("Successfully read %d bytes from %s\n", caKeySz, caKeyFile);
wc_ecc_init(&caKey);
initCaKey = 1;
printf("Decoding the CA private key\n");
idx = 0;
ret = wc_EccPrivateKeyDecode(caKeyBuf, &idx, &caKey, (word32)caKeySz);
if (ret != 0) goto exit;
printf("Successfully loaded CA Key\n\n");
/*------------------------------------------------------------------------*/
/* Generate new private key to go with our new cert */
/*------------------------------------------------------------------------*/
ret = wc_InitRng(&rng);
if (ret != 0) goto exit;
initRng = 1;
printf("Generating a new ECC key\n");
ret = wc_ecc_init(&newKey);
if (ret != 0) goto exit;
initNewKey = 1;
ret = wc_ecc_make_key(&rng, 32, &newKey);
if (ret != 0) goto exit;
printf("Successfully created new ECC key\n\n");
/*------------------------------------------------------------------------*/
/* Create a new certificate using SUBJECT information from ca cert
* for ISSUER information in generated cert */
/*------------------------------------------------------------------------*/
printf("Setting new cert issuer to subject of signer\n");
wc_InitCert(&newCert);
strncpy(newCert.subject.country, "US", CTC_NAME_SIZE);
strncpy(newCert.subject.state, "MT", CTC_NAME_SIZE);
strncpy(newCert.subject.locality, "Bozeman", CTC_NAME_SIZE);
strncpy(newCert.subject.org, "yourOrgNameHere", CTC_NAME_SIZE);
strncpy(newCert.subject.unit, "yourUnitNameHere", CTC_NAME_SIZE);
strncpy(newCert.subject.commonName, "www.yourDomain.com", CTC_NAME_SIZE);
strncpy(newCert.subject.email, "yourEmail@yourDomain.com", CTC_NAME_SIZE);
#ifdef WOLFSSL_ALT_NAMES
XMEMCPY(newCert.altNames, myAltNames, sizeof(myAltNames));
newCert.altNamesSz = (int) sizeof(myAltNames);
#endif
newCert.isCA = 0;
newCert.sigType = CTC_SHA256wECDSA;
ret = wc_SetIssuerBuffer(&newCert, derBuf, derBufSz);
if (ret != 0) goto exit;
ret = wc_MakeCert(&newCert, derBuf, LARGE_TEMP_SZ, NULL, &newKey, &rng);
if (ret < 0) goto exit;
printf("Make Cert returned %d\n", ret);
ret = wc_SignCert(newCert.bodySz, newCert.sigType, derBuf, LARGE_TEMP_SZ,
NULL, &caKey, &rng);
if (ret < 0) goto exit;
printf("Signed Cert returned %d\n", ret);
derBufSz = ret;
printf("Successfully created new certificate\n\n");
/*------------------------------------------------------------------------*/
/* write the new cert to file in der format */
/*------------------------------------------------------------------------*/
printf("Writing newly generated DER certificate to file \"%s\"\n",
newCertOutput);
file = fopen(newCertOutput, "wb");
if (!file) {
printf("failed to open file: %s\n", newCertOutput);
goto exit;
}
ret = (int)fwrite(derBuf, 1, derBufSz, file);
fclose(file);
printf("Successfully output %d bytes\n", ret);
#ifdef WOLFSSL_DER_TO_PEM
/*------------------------------------------------------------------------*/
/* convert the der to a pem and write it to a file */
/*------------------------------------------------------------------------*/
printf("Convert the DER cert to PEM formatted cert\n");
pemBuf = (byte*)XMALLOC(LARGE_TEMP_SZ, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER);
if (pemBuf == NULL) goto exit;
XMEMSET(pemBuf, 0, LARGE_TEMP_SZ);
pemBufSz = wc_DerToPem(derBuf, derBufSz, pemBuf, LARGE_TEMP_SZ, CERT_TYPE);
if (pemBufSz < 0) goto exit;
printf("Resulting PEM buffer is %d bytes\n", pemBufSz);
file = fopen(pemOutput, "wb");
if (!file) {
printf("failed to open file: %s\n", pemOutput);
goto exit;
}
fwrite(pemBuf, 1, pemBufSz, file);
fclose(file);
printf("Successfully converted the DER to PEM to \"%s\"\n\n",
pemOutput);
#endif
ret = 0; /* success */
exit:
XFREE(derBuf, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(pemBuf, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER);
XFREE(caKeyBuf, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER);
if (initCaKey)
wc_ecc_free(&caKey);
if (initNewKey)
wc_ecc_free(&newKey);
if (initRng) {
wc_FreeRng(&rng);
}
if (ret == 0)
printf("Tests passed\n");
else
printf("Failure code was %d\n", ret);
return ret;
}
#endif
int main(int argc, char** argv)
{
#if !defined(WOLFSSL_CERT_REQ) || !defined(WOLFSSL_CERT_GEN) || \
!defined(WOLFSSL_KEY_GEN) || !defined(HAVE_ECC)
printf("Please compile wolfSSL with --enable-certreq --enable-certgen "
"--enable-keygen --enable-ecc\n");
return 0;
#else
return do_certgen(argc, argv);
#endif
}