/*
* Certificate request generation
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#include "mbedtls/build_info.h"
#include "mbedtls/platform.h"
/* md.h is included this early since MD_CAN_XXX macros are defined there. */
#include "mbedtls/md.h"
#if !defined(MBEDTLS_X509_CSR_WRITE_C) || !defined(MBEDTLS_X509_CRT_PARSE_C) || \
!defined(MBEDTLS_PK_PARSE_C) || !defined(MBEDTLS_MD_CAN_SHA256) || \
!defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
!defined(MBEDTLS_PEM_WRITE_C) || !defined(MBEDTLS_FS_IO) || \
!defined(MBEDTLS_MD_C)
int main(void)
{
mbedtls_printf("MBEDTLS_X509_CSR_WRITE_C and/or MBEDTLS_FS_IO and/or "
"MBEDTLS_PK_PARSE_C and/or MBEDTLS_MD_CAN_SHA256 and/or "
"MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C "
"not defined.\n");
mbedtls_exit(0);
}
#else
#include "mbedtls/x509_csr.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/error.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define DFL_FILENAME "keyfile.key"
#define DFL_PASSWORD NULL
#define DFL_DEBUG_LEVEL 0
#define DFL_OUTPUT_FILENAME "cert.req"
#define DFL_SUBJECT_NAME "CN=Cert,O=mbed TLS,C=UK"
#define DFL_KEY_USAGE 0
#define DFL_FORCE_KEY_USAGE 0
#define DFL_NS_CERT_TYPE 0
#define DFL_FORCE_NS_CERT_TYPE 0
#define DFL_MD_ALG MBEDTLS_MD_SHA256
#define USAGE \
"\n usage: cert_req param=<>...\n" \
"\n acceptable parameters:\n" \
" filename=%%s default: keyfile.key\n" \
" password=%%s default: NULL\n" \
" debug_level=%%d default: 0 (disabled)\n" \
" output_file=%%s default: cert.req\n" \
" subject_name=%%s default: CN=Cert,O=mbed TLS,C=UK\n" \
" san=%%s default: (none)\n" \
" Semicolon-separated-list of values:\n" \
" DNS:value\n" \
" URI:value\n" \
" RFC822:value\n" \
" IP:value (Only IPv4 is supported)\n" \
" DN:list of comma separated key=value pairs\n" \
" key_usage=%%s default: (empty)\n" \
" Comma-separated-list of values:\n" \
" digital_signature\n" \
" non_repudiation\n" \
" key_encipherment\n" \
" data_encipherment\n" \
" key_agreement\n" \
" key_cert_sign\n" \
" crl_sign\n" \
" force_key_usage=0/1 default: off\n" \
" Add KeyUsage even if it is empty\n" \
" ns_cert_type=%%s default: (empty)\n" \
" Comma-separated-list of values:\n" \
" ssl_client\n" \
" ssl_server\n" \
" email\n" \
" object_signing\n" \
" ssl_ca\n" \
" email_ca\n" \
" object_signing_ca\n" \
" force_ns_cert_type=0/1 default: off\n" \
" Add NsCertType even if it is empty\n" \
" md=%%s default: SHA256\n" \
" possible values:\n" \
" MD5, RIPEMD160, SHA1,\n" \
" SHA224, SHA256, SHA384, SHA512\n" \
"\n"
/*
* global options
*/
struct options {
const char *filename; /* filename of the key file */
const char *password; /* password for the key file */
int debug_level; /* level of debugging */
const char *output_file; /* where to store the constructed key file */
const char *subject_name; /* subject name for certificate request */
mbedtls_x509_san_list *san_list; /* subjectAltName for certificate request */
unsigned char key_usage; /* key usage flags */
int force_key_usage; /* Force adding the KeyUsage extension */
unsigned char ns_cert_type; /* NS cert type */
int force_ns_cert_type; /* Force adding NsCertType extension */
mbedtls_md_type_t md_alg; /* Hash algorithm used for signature. */
} opt;
static int write_certificate_request(mbedtls_x509write_csr *req, const char *output_file,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng)
{
int ret;
FILE *f;
unsigned char output_buf[4096];
size_t len = 0;
memset(output_buf, 0, 4096);
if ((ret = mbedtls_x509write_csr_pem(req, output_buf, 4096, f_rng, p_rng)) < 0) {
return ret;
}
len = strlen((char *) output_buf);
if ((f = fopen(output_file, "w")) == NULL) {
return -1;
}
if (fwrite(output_buf, 1, len, f) != len) {
fclose(f);
return -1;
}
fclose(f);
return 0;
}
int main(int argc, char *argv[])
{
int ret = 1;
int exit_code = MBEDTLS_EXIT_FAILURE;
mbedtls_pk_context key;
char buf[1024];
int i;
char *p, *q, *r;
mbedtls_x509write_csr req;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
const char *pers = "csr example app";
mbedtls_x509_san_list *cur, *prev;
mbedtls_asn1_named_data *ext_san_dirname = NULL;
#if defined(MBEDTLS_X509_CRT_PARSE_C)
uint8_t ip[4] = { 0 };
#endif
/*
* Set to sane values
*/
mbedtls_x509write_csr_init(&req);
mbedtls_pk_init(&key);
mbedtls_ctr_drbg_init(&ctr_drbg);
memset(buf, 0, sizeof(buf));
mbedtls_entropy_init(&entropy);
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_status_t status = psa_crypto_init();
if (status != PSA_SUCCESS) {
mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
(int) status);
goto exit;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
if (argc < 2) {
usage:
mbedtls_printf(USAGE);
goto exit;
}
opt.filename = DFL_FILENAME;
opt.password = DFL_PASSWORD;
opt.debug_level = DFL_DEBUG_LEVEL;
opt.output_file = DFL_OUTPUT_FILENAME;
opt.subject_name = DFL_SUBJECT_NAME;
opt.key_usage = DFL_KEY_USAGE;
opt.force_key_usage = DFL_FORCE_KEY_USAGE;
opt.ns_cert_type = DFL_NS_CERT_TYPE;
opt.force_ns_cert_type = DFL_FORCE_NS_CERT_TYPE;
opt.md_alg = DFL_MD_ALG;
opt.san_list = NULL;
for (i = 1; i < argc; i++) {
p = argv[i];
if ((q = strchr(p, '=')) == NULL) {
goto usage;
}
*q++ = '\0';
if (strcmp(p, "filename") == 0) {
opt.filename = q;
} else if (strcmp(p, "password") == 0) {
opt.password = q;
} else if (strcmp(p, "output_file") == 0) {
opt.output_file = q;
} else if (strcmp(p, "debug_level") == 0) {
opt.debug_level = atoi(q);
if (opt.debug_level < 0 || opt.debug_level > 65535) {
goto usage;
}
} else if (strcmp(p, "subject_name") == 0) {
opt.subject_name = q;
} else if (strcmp(p, "san") == 0) {
char *subtype_value;
prev = NULL;
while (q != NULL) {
char *semicolon;
r = q;
/* Find the first non-escaped ; occurrence and remove escaped ones */
do {
if ((semicolon = strchr(r, ';')) != NULL) {
if (*(semicolon-1) != '\\') {
r = semicolon;
break;
}
/* Remove the escape character */
size_t size_left = strlen(semicolon);
memmove(semicolon-1, semicolon, size_left);
*(semicolon + size_left - 1) = '\0';
/* r will now point at the character after the semicolon */
r = semicolon;
}
} while (semicolon != NULL);
if (semicolon != NULL) {
*r++ = '\0';
} else {
r = NULL;
}
cur = mbedtls_calloc(1, sizeof(mbedtls_x509_san_list));
if (cur == NULL) {
mbedtls_printf("Not enough memory for subjectAltName list\n");
goto usage;
}
cur->next = NULL;
if ((subtype_value = strchr(q, ':')) != NULL) {
*subtype_value++ = '\0';
} else {
mbedtls_printf(
"Invalid argument for option SAN: Entry must be of the form TYPE:value\n");
goto usage;
}
if (strcmp(q, "RFC822") == 0) {
cur->node.type = MBEDTLS_X509_SAN_RFC822_NAME;
} else if (strcmp(q, "URI") == 0) {
cur->node.type = MBEDTLS_X509_SAN_UNIFORM_RESOURCE_IDENTIFIER;
} else if (strcmp(q, "DNS") == 0) {
cur->node.type = MBEDTLS_X509_SAN_DNS_NAME;
} else if (strcmp(q, "IP") == 0) {
size_t ip_addr_len = 0;
cur->node.type = MBEDTLS_X509_SAN_IP_ADDRESS;
ip_addr_len = mbedtls_x509_crt_parse_cn_inet_pton(subtype_value, ip);
if (ip_addr_len == 0) {
mbedtls_printf("mbedtls_x509_crt_parse_cn_inet_pton failed to parse %s\n",
subtype_value);
goto exit;
}
cur->node.san.unstructured_name.p = (unsigned char *) ip;
cur->node.san.unstructured_name.len = sizeof(ip);
} else if (strcmp(q, "DN") == 0) {
cur->node.type = MBEDTLS_X509_SAN_DIRECTORY_NAME;
if ((ret = mbedtls_x509_string_to_names(&ext_san_dirname,
subtype_value)) != 0) {
mbedtls_strerror(ret, buf, sizeof(buf));
mbedtls_printf(
" failed\n ! mbedtls_x509_string_to_names "
"returned -0x%04x - %s\n\n",
(unsigned int) -ret, buf);
goto exit;
}
cur->node.san.directory_name = *ext_san_dirname;
} else {
mbedtls_free(cur);
goto usage;
}
if (cur->node.type == MBEDTLS_X509_SAN_RFC822_NAME ||
cur->node.type == MBEDTLS_X509_SAN_UNIFORM_RESOURCE_IDENTIFIER ||
cur->node.type == MBEDTLS_X509_SAN_DNS_NAME) {
q = subtype_value;
cur->node.san.unstructured_name.p = (unsigned char *) q;
cur->node.san.unstructured_name.len = strlen(q);
}
if (prev == NULL) {
opt.san_list = cur;
} else {
prev->next = cur;
}
prev = cur;
q = r;
}
} else if (strcmp(p, "md") == 0) {
const mbedtls_md_info_t *md_info =
mbedtls_md_info_from_string(q);
if (md_info == NULL) {
mbedtls_printf("Invalid argument for option %s\n", p);
goto usage;
}
opt.md_alg = mbedtls_md_get_type(md_info);
} else if (strcmp(p, "key_usage") == 0) {
while (q != NULL) {
if ((r = strchr(q, ',')) != NULL) {
*r++ = '\0';
}
if (strcmp(q, "digital_signature") == 0) {
opt.key_usage |= MBEDTLS_X509_KU_DIGITAL_SIGNATURE;
} else if (strcmp(q, "non_repudiation") == 0) {
opt.key_usage |= MBEDTLS_X509_KU_NON_REPUDIATION;
} else if (strcmp(q, "key_encipherment") == 0) {
opt.key_usage |= MBEDTLS_X509_KU_KEY_ENCIPHERMENT;
} else if (strcmp(q, "data_encipherment") == 0) {
opt.key_usage |= MBEDTLS_X509_KU_DATA_ENCIPHERMENT;
} else if (strcmp(q, "key_agreement") == 0) {
opt.key_usage |= MBEDTLS_X509_KU_KEY_AGREEMENT;
} else if (strcmp(q, "key_cert_sign") == 0) {
opt.key_usage |= MBEDTLS_X509_KU_KEY_CERT_SIGN;
} else if (strcmp(q, "crl_sign") == 0) {
opt.key_usage |= MBEDTLS_X509_KU_CRL_SIGN;
} else {
goto usage;
}
q = r;
}
} else if (strcmp(p, "force_key_usage") == 0) {
switch (atoi(q)) {
case 0: opt.force_key_usage = 0; break;
case 1: opt.force_key_usage = 1; break;
default: goto usage;
}
} else if (strcmp(p, "ns_cert_type") == 0) {
while (q != NULL) {
if ((r = strchr(q, ',')) != NULL) {
*r++ = '\0';
}
if (strcmp(q, "ssl_client") == 0) {
opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT;
} else if (strcmp(q, "ssl_server") == 0) {
opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER;
} else if (strcmp(q, "email") == 0) {
opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_EMAIL;
} else if (strcmp(q, "object_signing") == 0) {
opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING;
} else if (strcmp(q, "ssl_ca") == 0) {
opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_CA;
} else if (strcmp(q, "email_ca") == 0) {
opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA;
} else if (strcmp(q, "object_signing_ca") == 0) {
opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA;
} else {
goto usage;
}
q = r;
}
} else if (strcmp(p, "force_ns_cert_type") == 0) {
switch (atoi(q)) {
case 0: opt.force_ns_cert_type = 0; break;
case 1: opt.force_ns_cert_type = 1; break;
default: goto usage;
}
} else {
goto usage;
}
}
/* Set the MD algorithm to use for the signature in the CSR */
mbedtls_x509write_csr_set_md_alg(&req, opt.md_alg);
/* Set the Key Usage Extension flags in the CSR */
if (opt.key_usage || opt.force_key_usage == 1) {
ret = mbedtls_x509write_csr_set_key_usage(&req, opt.key_usage);
if (ret != 0) {
mbedtls_printf(" failed\n ! mbedtls_x509write_csr_set_key_usage returned %d", ret);
goto exit;
}
}
/* Set the Cert Type flags in the CSR */
if (opt.ns_cert_type || opt.force_ns_cert_type == 1) {
ret = mbedtls_x509write_csr_set_ns_cert_type(&req, opt.ns_cert_type);
if (ret != 0) {
mbedtls_printf(" failed\n ! mbedtls_x509write_csr_set_ns_cert_type returned %d", ret);
goto exit;
}
}
/* Set the SubjectAltName in the CSR */
if (opt.san_list != NULL) {
ret = mbedtls_x509write_csr_set_subject_alternative_name(&req, opt.san_list);
if (ret != 0) {
mbedtls_printf(
" failed\n ! mbedtls_x509write_csr_set_subject_alternative_name returned %d",
ret);
goto exit;
}
}
/*
* 0. Seed the PRNG
*/
mbedtls_printf(" . Seeding the random number generator...");
fflush(stdout);
if ((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy,
(const unsigned char *) pers,
strlen(pers))) != 0) {
mbedtls_printf(" failed\n ! mbedtls_ctr_drbg_seed returned %d", ret);
goto exit;
}
mbedtls_printf(" ok\n");
/*
* 1.0. Check the subject name for validity
*/
mbedtls_printf(" . Checking subject name...");
fflush(stdout);
if ((ret = mbedtls_x509write_csr_set_subject_name(&req, opt.subject_name)) != 0) {
mbedtls_printf(" failed\n ! mbedtls_x509write_csr_set_subject_name returned %d", ret);
goto exit;
}
mbedtls_printf(" ok\n");
/*
* 1.1. Load the key
*/
mbedtls_printf(" . Loading the private key ...");
fflush(stdout);
ret = mbedtls_pk_parse_keyfile(&key, opt.filename, opt.password,
mbedtls_ctr_drbg_random, &ctr_drbg);
if (ret != 0) {
mbedtls_printf(" failed\n ! mbedtls_pk_parse_keyfile returned %d", ret);
goto exit;
}
mbedtls_x509write_csr_set_key(&req, &key);
mbedtls_printf(" ok\n");
/*
* 1.2. Writing the request
*/
mbedtls_printf(" . Writing the certificate request ...");
fflush(stdout);
if ((ret = write_certificate_request(&req, opt.output_file,
mbedtls_ctr_drbg_random, &ctr_drbg)) != 0) {
mbedtls_printf(" failed\n ! write_certificate_request %d", ret);
goto exit;
}
mbedtls_printf(" ok\n");
exit_code = MBEDTLS_EXIT_SUCCESS;
exit:
if (exit_code != MBEDTLS_EXIT_SUCCESS) {
#ifdef MBEDTLS_ERROR_C
mbedtls_strerror(ret, buf, sizeof(buf));
mbedtls_printf(" - %s\n", buf);
#else
mbedtls_printf("\n");
#endif
}
mbedtls_x509write_csr_free(&req);
mbedtls_asn1_free_named_data_list(&ext_san_dirname);
mbedtls_pk_free(&key);
mbedtls_ctr_drbg_free(&ctr_drbg);
mbedtls_entropy_free(&entropy);
#if defined(MBEDTLS_USE_PSA_CRYPTO)
mbedtls_psa_crypto_free();
#endif /* MBEDTLS_USE_PSA_CRYPTO */
cur = opt.san_list;
while (cur != NULL) {
prev = cur;
cur = cur->next;
mbedtls_free(prev);
}
mbedtls_exit(exit_code);
}
#endif /* MBEDTLS_X509_CSR_WRITE_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&
MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_PEM_WRITE_C */