mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-05 20:54:31 +00:00
4c17e5f691
fdt_add_bignum() is useful for algorithms other than just RSA. To allow its use for ECDSA, move it to a common file under lib/. The new file is suffixed with '-libcrypto' because it has a direct dependency on openssl. This is due to the use of the "BIGNUM *" type. Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright (c) 2020, Alexandru Gagniuc <mr.nuke.me@gmail.com>
|
|
* Copyright (c) 2013, Google Inc.
|
|
*/
|
|
|
|
#include <libfdt.h>
|
|
#include <u-boot/fdt-libcrypto.h>
|
|
|
|
int fdt_add_bignum(void *blob, int noffset, const char *prop_name,
|
|
BIGNUM *num, int num_bits)
|
|
{
|
|
int nwords = num_bits / 32;
|
|
int size;
|
|
uint32_t *buf, *ptr;
|
|
BIGNUM *tmp, *big2, *big32, *big2_32;
|
|
BN_CTX *ctx;
|
|
int ret;
|
|
|
|
tmp = BN_new();
|
|
big2 = BN_new();
|
|
big32 = BN_new();
|
|
big2_32 = BN_new();
|
|
|
|
/*
|
|
* Note: This code assumes that all of the above succeed, or all fail.
|
|
* In practice memory allocations generally do not fail (unless the
|
|
* process is killed), so it does not seem worth handling each of these
|
|
* as a separate case. Technicaly this could leak memory on failure,
|
|
* but a) it won't happen in practice, and b) it doesn't matter as we
|
|
* will immediately exit with a failure code.
|
|
*/
|
|
if (!tmp || !big2 || !big32 || !big2_32) {
|
|
fprintf(stderr, "Out of memory (bignum)\n");
|
|
return -ENOMEM;
|
|
}
|
|
ctx = BN_CTX_new();
|
|
if (!ctx) {
|
|
fprintf(stderr, "Out of memory (bignum context)\n");
|
|
return -ENOMEM;
|
|
}
|
|
BN_set_word(big2, 2L);
|
|
BN_set_word(big32, 32L);
|
|
BN_exp(big2_32, big2, big32, ctx); /* B = 2^32 */
|
|
|
|
size = nwords * sizeof(uint32_t);
|
|
buf = malloc(size);
|
|
if (!buf) {
|
|
fprintf(stderr, "Out of memory (%d bytes)\n", size);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Write out modulus as big endian array of integers */
|
|
for (ptr = buf + nwords - 1; ptr >= buf; ptr--) {
|
|
BN_mod(tmp, num, big2_32, ctx); /* n = N mod B */
|
|
*ptr = cpu_to_fdt32(BN_get_word(tmp));
|
|
BN_rshift(num, num, 32); /* N = N/B */
|
|
}
|
|
|
|
/*
|
|
* We try signing with successively increasing size values, so this
|
|
* might fail several times
|
|
*/
|
|
ret = fdt_setprop(blob, noffset, prop_name, buf, size);
|
|
free(buf);
|
|
BN_free(tmp);
|
|
BN_free(big2);
|
|
BN_free(big32);
|
|
BN_free(big2_32);
|
|
|
|
return ret ? -FDT_ERR_NOSPACE : 0;
|
|
}
|