/*
* Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include "brssl.h"
#include "bearssl.h"
typedef struct {
int print_text;
int print_C;
const char *rawder;
const char *rawpem;
const char *pk8der;
const char *pk8pem;
} outspec;
static void
print_int_text(const char *name, const unsigned char *buf, size_t len)
{
size_t u;
printf("%s = ", name);
for (u = 0; u < len; u ++) {
printf("%02X", buf[u]);
}
printf("\n");
}
static void
print_int_C(const char *name, const unsigned char *buf, size_t len)
{
size_t u;
printf("\nstatic const unsigned char %s[] = {", name);
for (u = 0; u < len; u ++) {
if (u != 0) {
printf(",");
}
if (u % 12 == 0) {
printf("\n\t");
} else {
printf(" ");
}
printf("0x%02X", buf[u]);
}
printf("\n};\n");
}
static int
write_to_file(const char *name, const void *data, size_t len)
{
FILE *f;
f = fopen(name, "wb");
if (f == NULL) {
fprintf(stderr,
"ERROR: cannot open file '%s' for writing\n",
name);
return 0;
}
if (fwrite(data, 1, len, f) != len) {
fclose(f);
fprintf(stderr,
"ERROR: cannot write to file '%s'\n",
name);
return 0;
}
fclose(f);
return 1;
}
static int
write_to_pem_file(const char *name,
const void *data, size_t len, const char *banner)
{
void *pem;
size_t pemlen;
int r;
pemlen = br_pem_encode(NULL, NULL, len, banner, 0);
pem = xmalloc(pemlen + 1);
br_pem_encode(pem, data, len, banner, 0);
r = write_to_file(name, pem, pemlen);
xfree(pem);
return r;
}
static int
print_rsa(const br_rsa_private_key *sk, outspec *os)
{
int ret;
unsigned char *n, *d, *buf;
uint32_t e;
size_t nlen, dlen, len;
br_rsa_compute_modulus cm;
br_rsa_compute_pubexp ce;
br_rsa_compute_privexp cd;
br_rsa_public_key pk;
unsigned char ebuf[4];
n = NULL;
d = NULL;
buf = NULL;
ret = 1;
if (os->print_text) {
print_int_text("p ", sk->p, sk->plen);
print_int_text("q ", sk->q, sk->qlen);
print_int_text("dp", sk->dp, sk->dplen);
print_int_text("dq", sk->dq, sk->dqlen);
print_int_text("iq", sk->iq, sk->iqlen);
}
if (os->print_C) {
print_int_C("RSA_P", sk->p, sk->plen);
print_int_C("RSA_Q", sk->q, sk->qlen);
print_int_C("RSA_DP", sk->dp, sk->dplen);
print_int_C("RSA_DQ", sk->dq, sk->dqlen);
print_int_C("RSA_IQ", sk->iq, sk->iqlen);
printf("\nstatic const br_rsa_private_key RSA = {\n");
printf("\t%lu,\n", (unsigned long)sk->n_bitlen);
printf("\t(unsigned char *)RSA_P, sizeof RSA_P,\n");
printf("\t(unsigned char *)RSA_Q, sizeof RSA_Q,\n");
printf("\t(unsigned char *)RSA_DP, sizeof RSA_DP,\n");
printf("\t(unsigned char *)RSA_DQ, sizeof RSA_DQ,\n");
printf("\t(unsigned char *)RSA_IQ, sizeof RSA_IQ\n");
printf("};\n");
}
if (os->rawder == NULL && os->rawpem == NULL
&& os->pk8der == NULL && os->pk8pem == NULL)
{
return ret;
}
cm = br_rsa_compute_modulus_get_default();
ce = br_rsa_compute_pubexp_get_default();
cd = br_rsa_compute_privexp_get_default();
nlen = cm(NULL, sk);
if (nlen == 0) {
goto print_RSA_error;
}
n = xmalloc(nlen);
if (cm(n, sk) != nlen) {
goto print_RSA_error;
}
e = ce(sk);
if (e == 0) {
goto print_RSA_error;
}
dlen = cd(NULL, sk, e);
if (dlen == 0) {
goto print_RSA_error;
}
d = xmalloc(dlen);
if (cd(d, sk, e) != dlen) {
goto print_RSA_error;
}
ebuf[0] = e >> 24;
ebuf[1] = e >> 16;
ebuf[2] = e >> 8;
ebuf[3] = e;
pk.n = n;
pk.nlen = nlen;
pk.e = ebuf;
pk.elen = sizeof ebuf;
if (os->rawder != NULL || os->rawpem != NULL) {
len = br_encode_rsa_raw_der(NULL, sk, &pk, d, dlen);
if (len == 0) {
goto print_RSA_error;
}
buf = xmalloc(len);
if (br_encode_rsa_raw_der(buf, sk, &pk, d, dlen) != len) {
goto print_RSA_error;
}
if (os->rawder != NULL) {
ret &= write_to_file(os->rawder, buf, len);
}
if (os->rawpem != NULL) {
ret &= write_to_pem_file(os->rawpem,
buf, len, "RSA PRIVATE KEY");
}
xfree(buf);
buf = NULL;
}
if (os->pk8der != NULL || os->pk8pem != NULL) {
len = br_encode_rsa_pkcs8_der(NULL, sk, &pk, d, dlen);
if (len == 0) {
goto print_RSA_error;
}
buf = xmalloc(len);
if (br_encode_rsa_pkcs8_der(buf, sk, &pk, d, dlen) != len) {
goto print_RSA_error;
}
if (os->pk8der != NULL) {
ret &= write_to_file(os->pk8der, buf, len);
}
if (os->pk8pem != NULL) {
ret &= write_to_pem_file(os->pk8pem,
buf, len, "PRIVATE KEY");
}
xfree(buf);
buf = NULL;
}
print_RSA_exit:
xfree(n);
xfree(d);
xfree(buf);
return ret;
print_RSA_error:
fprintf(stderr, "ERROR: cannot encode RSA key\n");
ret = 0;
goto print_RSA_exit;
}
static int
print_ec(const br_ec_private_key *sk, outspec *os)
{
br_ec_public_key pk;
unsigned kbuf[BR_EC_KBUF_PUB_MAX_SIZE];
unsigned char *buf;
size_t len;
int r;
if (os->print_text) {
print_int_text("x", sk->x, sk->xlen);
}
if (os->print_C) {
print_int_C("EC_X", sk->x, sk->xlen);
printf("\nstatic const br_ec_private_key EC = {\n");
printf("\t%d,\n", sk->curve);
printf("\t(unsigned char *)EC_X, sizeof EC_X\n");
printf("};\n");
}
if (os->rawder == NULL && os->rawpem == NULL
&& os->pk8der == NULL && os->pk8pem == NULL)
{
return 1;
}
if (br_ec_compute_pub(br_ec_get_default(), &pk, kbuf, sk) == 0) {
fprintf(stderr,
"ERROR: cannot re-encode (unsupported curve)\n");
return 0;
}
r = 1;
if (os->rawder != NULL || os->rawpem != NULL) {
len = br_encode_ec_raw_der(NULL, sk, &pk);
if (len == 0) {
fprintf(stderr, "ERROR: cannot re-encode"
" (unsupported curve)\n");
return 0;
}
buf = xmalloc(len);
if (br_encode_ec_raw_der(buf, sk, &pk) != len) {
fprintf(stderr, "ERROR: re-encode failure\n");
xfree(buf);
return 0;
}
if (os->rawder != NULL) {
r &= write_to_file(os->rawder, buf, len);
}
if (os->rawpem != NULL) {
r &= write_to_pem_file(os->rawpem,
buf, len, "EC PRIVATE KEY");
}
xfree(buf);
}
if (os->pk8der != NULL || os->pk8pem != NULL) {
len = br_encode_ec_pkcs8_der(NULL, sk, &pk);
if (len == 0) {
fprintf(stderr, "ERROR: cannot re-encode"
" (unsupported curve)\n");
return 0;
}
buf = xmalloc(len);
if (br_encode_ec_pkcs8_der(buf, sk, &pk) != len) {
fprintf(stderr, "ERROR: re-encode failure\n");
xfree(buf);
return 0;
}
if (os->pk8der != NULL) {
r &= write_to_file(os->pk8der, buf, len);
}
if (os->pk8pem != NULL) {
r &= write_to_pem_file(os->pk8pem,
buf, len, "PRIVATE KEY");
}
xfree(buf);
}
return r;
}
static int
parse_rsa_spec(const char *kgen_spec, unsigned *size, uint32_t *pubexp)
{
const char *p;
char *end;
unsigned long ul;
p = kgen_spec;
if (*p != 'r' && *p != 'R') {
return 0;
}
p ++;
if (*p != 's' && *p != 'S') {
return 0;
}
p ++;
if (*p != 'a' && *p != 'A') {
return 0;
}
p ++;
if (*p == 0) {
*size = 2048;
*pubexp = 3;
return 1;
} else if (*p != ':') {
return 0;
}
p ++;
ul = strtoul(p, &end, 10);
if (ul < 512 || ul > 32768) {
return 0;
}
*size = ul;
p = end;
if (*p == 0) {
*pubexp = 3;
return 1;
} else if (*p != ':') {
return 0;
}
p ++;
ul = strtoul(p, &end, 10);
if ((ul & 1) == 0 || ul == 1 || ((ul >> 30) >> 2) != 0) {
return 0;
}
*pubexp = ul;
if (*end != 0) {
return 0;
}
return 1;
}
static int
keygen_rsa(unsigned size, uint32_t pubexp, outspec *os)
{
br_hmac_drbg_context rng;
br_prng_seeder seeder;
br_rsa_keygen kg;
br_rsa_private_key sk;
unsigned char *kbuf_priv;
uint32_t r;
seeder = br_prng_seeder_system(NULL);
if (seeder == 0) {
fprintf(stderr, "ERROR: no system source of randomness\n");
return 0;
}
br_hmac_drbg_init(&rng, &br_sha256_vtable, NULL, 0);
if (!seeder(&rng.vtable)) {
fprintf(stderr, "ERROR: system source of randomness failed\n");
return 0;
}
kbuf_priv = xmalloc(BR_RSA_KBUF_PRIV_SIZE(size));
kg = br_rsa_keygen_get_default();
r = kg(&rng.vtable, &sk, kbuf_priv, NULL, NULL, size, pubexp);
if (!r) {
fprintf(stderr, "ERROR: RSA key pair generation failed\n");
} else {
r = print_rsa(&sk, os);
}
xfree(kbuf_priv);
return r;
}
static int
parse_ec_spec(const char *kgen_spec, int *curve)
{
const char *p;
*curve = 0;
p = kgen_spec;
if (*p != 'e' && *p != 'E') {
return 0;
}
p ++;
if (*p != 'c' && *p != 'C') {
return 0;
}
p ++;
if (*p == 0) {
*curve = BR_EC_secp256r1;
return 1;
}
if (*p != ':') {
return 0;
}
*curve = get_curve_by_name(p);
return *curve > 0;
}
static int
keygen_ec(int curve, outspec *os)
{
br_hmac_drbg_context rng;
br_prng_seeder seeder;
const br_ec_impl *impl;
br_ec_private_key sk;
unsigned char kbuf_priv[BR_EC_KBUF_PRIV_MAX_SIZE];
size_t len;
seeder = br_prng_seeder_system(NULL);
if (seeder == 0) {
fprintf(stderr, "ERROR: no system source of randomness\n");
return 0;
}
br_hmac_drbg_init(&rng, &br_sha256_vtable, NULL, 0);
if (!seeder(&rng.vtable)) {
fprintf(stderr, "ERROR: system source of randomness failed\n");
return 0;
}
impl = br_ec_get_default();
len = br_ec_keygen(&rng.vtable, impl, &sk, kbuf_priv, curve);
if (len == 0) {
fprintf(stderr, "ERROR: curve is not supported\n");
return 0;
}
return print_ec(&sk, os);
}
static int
decode_key(const unsigned char *buf, size_t len, outspec *os)
{
br_skey_decoder_context dc;
int err, ret;
br_skey_decoder_init(&dc);
br_skey_decoder_push(&dc, buf, len);
err = br_skey_decoder_last_error(&dc);
if (err != 0) {
const char *errname, *errmsg;
fprintf(stderr, "ERROR (decoding): err=%d\n", err);
errname = find_error_name(err, &errmsg);
if (errname != NULL) {
fprintf(stderr, " %s: %s\n", errname, errmsg);
} else {
fprintf(stderr, " (unknown)\n");
}
return 0;
}
ret = 1;
switch (br_skey_decoder_key_type(&dc)) {
const br_rsa_private_key *rk;
const br_ec_private_key *ek;
case BR_KEYTYPE_RSA:
rk = br_skey_decoder_get_rsa(&dc);
printf("RSA key (%lu bits)\n", (unsigned long)rk->n_bitlen);
ret = print_rsa(rk, os);
break;
case BR_KEYTYPE_EC:
ek = br_skey_decoder_get_ec(&dc);
printf("EC key (curve = %d: %s)\n",
ek->curve, ec_curve_name(ek->curve));
ret = print_ec(ek, os);
break;
default:
fprintf(stderr, "Unknown key type: %d\n",
br_skey_decoder_key_type(&dc));
ret = 0;
break;
}
return ret;
}
static void
usage_skey(void)
{
fprintf(stderr,
"usage: brssl skey [ options ] file...\n");
fprintf(stderr,
"options:\n");
fprintf(stderr,
" -q suppress verbose messages\n");
fprintf(stderr,
" -text print private key details (human-readable)\n");
fprintf(stderr,
" -C print private key details (C code)\n");
fprintf(stderr,
" -rawder file save private key in 'file' (raw format, DER)\n");
fprintf(stderr,
" -rawpem file save private key in 'file' (raw format, PEM)\n");
fprintf(stderr,
" -pk8der file save private key in 'file' (PKCS#8 format, DER)\n");
fprintf(stderr,
" -pk8pem file save private key in 'file' (PKCS#8 format, PEM)\n");
fprintf(stderr,
" -gen spec generate a new key using the provided key specification\n");
fprintf(stderr,
" -list list known elliptic curve names\n");
fprintf(stderr,
"Key specification begins with a key type, followed by optional parameters\n");
fprintf(stderr,
"that depend on the key type, separated by colon characters:\n");
fprintf(stderr,
" rsa[:size[:pubexep]] RSA key (defaults: size = 2048, pubexp = 3)\n");
fprintf(stderr,
" ec[:curvename] EC key (default curve: secp256r1)\n");
}
/* see brssl.h */
int
do_skey(int argc, char *argv[])
{
int retcode;
int verbose;
int i, num_files;
outspec os;
unsigned char *buf;
size_t len;
pem_object *pos;
const char *kgen_spec;
retcode = 0;
verbose = 1;
os.print_text = 0;
os.print_C = 0;
os.rawder = NULL;
os.rawpem = NULL;
os.pk8der = NULL;
os.pk8pem = NULL;
num_files = 0;
buf = NULL;
pos = NULL;
kgen_spec = NULL;
for (i = 0; i < argc; i ++) {
const char *arg;
arg = argv[i];
if (arg[0] != '-') {
num_files ++;
continue;
}
argv[i] = NULL;
if (eqstr(arg, "-v") || eqstr(arg, "-verbose")) {
verbose = 1;
} else if (eqstr(arg, "-q") || eqstr(arg, "-quiet")) {
verbose = 0;
} else if (eqstr(arg, "-text")) {
os.print_text = 1;
} else if (eqstr(arg, "-C")) {
os.print_C = 1;
} else if (eqstr(arg, "-rawder")) {
if (++ i >= argc) {
fprintf(stderr,
"ERROR: no argument for '-rawder'\n");
usage_skey();
goto skey_exit_error;
}
if (os.rawder != NULL) {
fprintf(stderr,
"ERROR: multiple '-rawder' options\n");
usage_skey();
goto skey_exit_error;
}
os.rawder = argv[i];
argv[i] = NULL;
} else if (eqstr(arg, "-rawpem")) {
if (++ i >= argc) {
fprintf(stderr,
"ERROR: no argument for '-rawpem'\n");
usage_skey();
goto skey_exit_error;
}
if (os.rawpem != NULL) {
fprintf(stderr,
"ERROR: multiple '-rawpem' options\n");
usage_skey();
goto skey_exit_error;
}
os.rawpem = argv[i];
argv[i] = NULL;
} else if (eqstr(arg, "-pk8der")) {
if (++ i >= argc) {
fprintf(stderr,
"ERROR: no argument for '-pk8der'\n");
usage_skey();
goto skey_exit_error;
}
if (os.pk8der != NULL) {
fprintf(stderr,
"ERROR: multiple '-pk8der' options\n");
usage_skey();
goto skey_exit_error;
}
os.pk8der = argv[i];
argv[i] = NULL;
} else if (eqstr(arg, "-pk8pem")) {
if (++ i >= argc) {
fprintf(stderr,
"ERROR: no argument for '-pk8pem'\n");
usage_skey();
goto skey_exit_error;
}
if (os.pk8pem != NULL) {
fprintf(stderr,
"ERROR: multiple '-pk8pem' options\n");
usage_skey();
goto skey_exit_error;
}
os.pk8pem = argv[i];
argv[i] = NULL;
} else if (eqstr(arg, "-gen")) {
if (++ i >= argc) {
fprintf(stderr,
"ERROR: no argument for '-gen'\n");
usage_skey();
goto skey_exit_error;
}
if (kgen_spec != NULL) {
fprintf(stderr,
"ERROR: multiple '-gen' options\n");
usage_skey();
goto skey_exit_error;
}
kgen_spec = argv[i];
argv[i] = NULL;
} else if (eqstr(arg, "-list")) {
list_curves();
goto skey_exit;
} else {
fprintf(stderr, "ERROR: unknown option: '%s'\n", arg);
usage_skey();
goto skey_exit_error;
}
}
if (kgen_spec != NULL) {
unsigned rsa_size;
uint32_t rsa_pubexp;
int curve;
if (num_files != 0) {
fprintf(stderr,
"ERROR: key files provided while generating\n");
usage_skey();
goto skey_exit_error;
}
if (parse_rsa_spec(kgen_spec, &rsa_size, &rsa_pubexp)) {
if (!keygen_rsa(rsa_size, rsa_pubexp, &os)) {
goto skey_exit_error;
}
} else if (parse_ec_spec(kgen_spec, &curve)) {
if (!keygen_ec(curve, &os)) {
goto skey_exit_error;
}
} else {
fprintf(stderr,
"ERROR: unknown key specification: '%s'\n",
kgen_spec);
usage_skey();
goto skey_exit_error;
}
} else if (num_files == 0) {
fprintf(stderr, "ERROR: no private key provided\n");
usage_skey();
goto skey_exit_error;
}
for (i = 0; i < argc; i ++) {
const char *fname;
fname = argv[i];
if (fname == NULL) {
continue;
}
buf = read_file(fname, &len);
if (buf == NULL) {
goto skey_exit_error;
}
if (looks_like_DER(buf, len)) {
if (verbose) {
fprintf(stderr, "File '%s': ASN.1/DER object\n",
fname);
}
if (!decode_key(buf, len, &os)) {
goto skey_exit_error;
}
} else {
size_t u, num;
if (verbose) {
fprintf(stderr, "File '%s': decoding as PEM\n",
fname);
}
pos = decode_pem(buf, len, &num);
if (pos == NULL) {
goto skey_exit_error;
}
for (u = 0; pos[u].name; u ++) {
const char *name;
name = pos[u].name;
if (eqstr(name, "RSA PRIVATE KEY")
|| eqstr(name, "EC PRIVATE KEY")
|| eqstr(name, "PRIVATE KEY"))
{
if (!decode_key(pos[u].data,
pos[u].data_len, &os))
{
goto skey_exit_error;
}
} else {
if (verbose) {
fprintf(stderr,
"(skipping '%s')\n",
name);
}
}
}
for (u = 0; pos[u].name; u ++) {
free_pem_object_contents(&pos[u]);
}
xfree(pos);
pos = NULL;
}
xfree(buf);
buf = NULL;
}
/*
* Release allocated structures.
*/
skey_exit:
xfree(buf);
if (pos != NULL) {
size_t u;
for (u = 0; pos[u].name; u ++) {
free_pem_object_contents(&pos[u]);
}
xfree(pos);
}
return retcode;
skey_exit_error:
retcode = -1;
goto skey_exit;
}