static int get_rsa_pub_key(const char *path, struct rsa_public_key *key)
{
BIGNUM *modulus, *r_squared;
uint32_t n0_inv;
int ret;
int bits;
RSA *rsa;
ret = rsa_get_pub_key(path, &rsa);
if (ret)
return ret;
ret = rsa_get_params(rsa, &n0_inv, &modulus, &r_squared);
if (ret)
return ret;
bits = BN_num_bits(modulus);
get_key_bignum(modulus, bits, key->modulus);
get_key_bignum(r_squared, bits, key->rr);
key->len = htonl(bits);
key->n0inv = htonl(n0_inv);
BN_free(modulus);
BN_free(r_squared);
return 0;
}
int rsa_add_verify_data(struct image_sign_info *info, void *keydest)
{
BIGNUM *modulus, *r_squared;
uint64_t exponent;
uint32_t n0_inv;
int parent, node;
char name[100];
int ret;
int bits;
RSA *rsa;
debug("%s: Getting verification data\n", __func__);
ret = rsa_get_pub_key(info->keydir, info->keyname, &rsa);
if (ret)
return ret;
ret = rsa_get_params(rsa, &exponent, &n0_inv, &modulus, &r_squared);
if (ret)
return ret;
bits = BN_num_bits(modulus);
parent = fdt_subnode_offset(keydest, 0, FIT_SIG_NODENAME);
if (parent == -FDT_ERR_NOTFOUND) {
parent = fdt_add_subnode(keydest, 0, FIT_SIG_NODENAME);
if (parent < 0) {
ret = parent;
if (ret != -FDT_ERR_NOSPACE) {
fprintf(stderr, "Couldn't create signature node: %s\n",
fdt_strerror(parent));
}
}
}
if (ret)
goto done;
/* Either create or overwrite the named key node */
snprintf(name, sizeof(name), "key-%s", info->keyname);
node = fdt_subnode_offset(keydest, parent, name);
if (node == -FDT_ERR_NOTFOUND) {
node = fdt_add_subnode(keydest, parent, name);
if (node < 0) {
ret = node;
if (ret != -FDT_ERR_NOSPACE) {
fprintf(stderr, "Could not create key subnode: %s\n",
fdt_strerror(node));
}
}
} else if (node < 0) {
fprintf(stderr, "Cannot select keys parent: %s\n",
fdt_strerror(node));
ret = node;
}
if (!ret) {
ret = fdt_setprop_string(keydest, node, "key-name-hint",
info->keyname);
}
if (!ret)
ret = fdt_setprop_u32(keydest, node, "rsa,num-bits", bits);
if (!ret)
ret = fdt_setprop_u32(keydest, node, "rsa,n0-inverse", n0_inv);
if (!ret) {
ret = fdt_setprop_u64(keydest, node, "rsa,exponent", exponent);
}
if (!ret) {
ret = fdt_add_bignum(keydest, node, "rsa,modulus", modulus,
bits);
}
if (!ret) {
ret = fdt_add_bignum(keydest, node, "rsa,r-squared", r_squared,
bits);
}
if (!ret) {
ret = fdt_setprop_string(keydest, node, FIT_ALGO_PROP,
info->name);
}
if (!ret && info->require_keys) {
ret = fdt_setprop_string(keydest, node, "required",
info->require_keys);
}
done:
BN_free(modulus);
BN_free(r_squared);
if (ret)
return ret == -FDT_ERR_NOSPACE ? -ENOSPC : -EIO;
return 0;
}