commit 18b06652cd
"tools: include u-boot version of sha256.h"
unconditionally forced the sha256.h from u-boot to be used
for tools instead of the host version. This is fragile though
as it will also include the host version. Therefore move it
to include/u-boot to join u-boot/md5.h etc which were renamed
for the same reason.
cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
340 lines
8.8 KiB
C
340 lines
8.8 KiB
C
/*
|
|
* Copyright (c) 2013, Google Inc.
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#ifndef USE_HOSTCC
|
|
#include <common.h>
|
|
#include <fdtdec.h>
|
|
#include <asm/types.h>
|
|
#include <asm/byteorder.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/types.h>
|
|
#include <asm/unaligned.h>
|
|
#else
|
|
#include "fdt_host.h"
|
|
#include "mkimage.h"
|
|
#include <fdt_support.h>
|
|
#endif
|
|
#include <u-boot/rsa.h>
|
|
#include <u-boot/sha1.h>
|
|
#include <u-boot/sha256.h>
|
|
|
|
#define UINT64_MULT32(v, multby) (((uint64_t)(v)) * ((uint32_t)(multby)))
|
|
|
|
#define get_unaligned_be32(a) fdt32_to_cpu(*(uint32_t *)a)
|
|
#define put_unaligned_be32(a, b) (*(uint32_t *)(b) = cpu_to_fdt32(a))
|
|
|
|
/**
|
|
* subtract_modulus() - subtract modulus from the given value
|
|
*
|
|
* @key: Key containing modulus to subtract
|
|
* @num: Number to subtract modulus from, as little endian word array
|
|
*/
|
|
static void subtract_modulus(const struct rsa_public_key *key, uint32_t num[])
|
|
{
|
|
int64_t acc = 0;
|
|
uint i;
|
|
|
|
for (i = 0; i < key->len; i++) {
|
|
acc += (uint64_t)num[i] - key->modulus[i];
|
|
num[i] = (uint32_t)acc;
|
|
acc >>= 32;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* greater_equal_modulus() - check if a value is >= modulus
|
|
*
|
|
* @key: Key containing modulus to check
|
|
* @num: Number to check against modulus, as little endian word array
|
|
* @return 0 if num < modulus, 1 if num >= modulus
|
|
*/
|
|
static int greater_equal_modulus(const struct rsa_public_key *key,
|
|
uint32_t num[])
|
|
{
|
|
uint32_t i;
|
|
|
|
for (i = key->len - 1; i >= 0; i--) {
|
|
if (num[i] < key->modulus[i])
|
|
return 0;
|
|
if (num[i] > key->modulus[i])
|
|
return 1;
|
|
}
|
|
|
|
return 1; /* equal */
|
|
}
|
|
|
|
/**
|
|
* montgomery_mul_add_step() - Perform montgomery multiply-add step
|
|
*
|
|
* Operation: montgomery result[] += a * b[] / n0inv % modulus
|
|
*
|
|
* @key: RSA key
|
|
* @result: Place to put result, as little endian word array
|
|
* @a: Multiplier
|
|
* @b: Multiplicand, as little endian word array
|
|
*/
|
|
static void montgomery_mul_add_step(const struct rsa_public_key *key,
|
|
uint32_t result[], const uint32_t a, const uint32_t b[])
|
|
{
|
|
uint64_t acc_a, acc_b;
|
|
uint32_t d0;
|
|
uint i;
|
|
|
|
acc_a = (uint64_t)a * b[0] + result[0];
|
|
d0 = (uint32_t)acc_a * key->n0inv;
|
|
acc_b = (uint64_t)d0 * key->modulus[0] + (uint32_t)acc_a;
|
|
for (i = 1; i < key->len; i++) {
|
|
acc_a = (acc_a >> 32) + (uint64_t)a * b[i] + result[i];
|
|
acc_b = (acc_b >> 32) + (uint64_t)d0 * key->modulus[i] +
|
|
(uint32_t)acc_a;
|
|
result[i - 1] = (uint32_t)acc_b;
|
|
}
|
|
|
|
acc_a = (acc_a >> 32) + (acc_b >> 32);
|
|
|
|
result[i - 1] = (uint32_t)acc_a;
|
|
|
|
if (acc_a >> 32)
|
|
subtract_modulus(key, result);
|
|
}
|
|
|
|
/**
|
|
* montgomery_mul() - Perform montgomery mutitply
|
|
*
|
|
* Operation: montgomery result[] = a[] * b[] / n0inv % modulus
|
|
*
|
|
* @key: RSA key
|
|
* @result: Place to put result, as little endian word array
|
|
* @a: Multiplier, as little endian word array
|
|
* @b: Multiplicand, as little endian word array
|
|
*/
|
|
static void montgomery_mul(const struct rsa_public_key *key,
|
|
uint32_t result[], uint32_t a[], const uint32_t b[])
|
|
{
|
|
uint i;
|
|
|
|
for (i = 0; i < key->len; ++i)
|
|
result[i] = 0;
|
|
for (i = 0; i < key->len; ++i)
|
|
montgomery_mul_add_step(key, result, a[i], b);
|
|
}
|
|
|
|
/**
|
|
* pow_mod() - in-place public exponentiation
|
|
*
|
|
* @key: RSA key
|
|
* @inout: Big-endian word array containing value and result
|
|
*/
|
|
static int pow_mod(const struct rsa_public_key *key, uint32_t *inout)
|
|
{
|
|
uint32_t *result, *ptr;
|
|
uint i;
|
|
|
|
/* Sanity check for stack size - key->len is in 32-bit words */
|
|
if (key->len > RSA_MAX_KEY_BITS / 32) {
|
|
debug("RSA key words %u exceeds maximum %d\n", key->len,
|
|
RSA_MAX_KEY_BITS / 32);
|
|
return -EINVAL;
|
|
}
|
|
|
|
uint32_t val[key->len], acc[key->len], tmp[key->len];
|
|
result = tmp; /* Re-use location. */
|
|
|
|
/* Convert from big endian byte array to little endian word array. */
|
|
for (i = 0, ptr = inout + key->len - 1; i < key->len; i++, ptr--)
|
|
val[i] = get_unaligned_be32(ptr);
|
|
|
|
montgomery_mul(key, acc, val, key->rr); /* axx = a * RR / R mod M */
|
|
for (i = 0; i < 16; i += 2) {
|
|
montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod M */
|
|
montgomery_mul(key, acc, tmp, tmp); /* acc = tmp^2 / R mod M */
|
|
}
|
|
montgomery_mul(key, result, acc, val); /* result = XX * a / R mod M */
|
|
|
|
/* Make sure result < mod; result is at most 1x mod too large. */
|
|
if (greater_equal_modulus(key, result))
|
|
subtract_modulus(key, result);
|
|
|
|
/* Convert to bigendian byte array */
|
|
for (i = key->len - 1, ptr = inout; (int)i >= 0; i--, ptr++)
|
|
put_unaligned_be32(result[i], ptr);
|
|
return 0;
|
|
}
|
|
|
|
static int rsa_verify_key(const struct rsa_public_key *key, const uint8_t *sig,
|
|
const uint32_t sig_len, const uint8_t *hash,
|
|
struct checksum_algo *algo)
|
|
{
|
|
const uint8_t *padding;
|
|
int pad_len;
|
|
int ret;
|
|
|
|
if (!key || !sig || !hash || !algo)
|
|
return -EIO;
|
|
|
|
if (sig_len != (key->len * sizeof(uint32_t))) {
|
|
debug("Signature is of incorrect length %d\n", sig_len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
debug("Checksum algorithm: %s", algo->name);
|
|
|
|
/* Sanity check for stack size */
|
|
if (sig_len > RSA_MAX_SIG_BITS / 8) {
|
|
debug("Signature length %u exceeds maximum %d\n", sig_len,
|
|
RSA_MAX_SIG_BITS / 8);
|
|
return -EINVAL;
|
|
}
|
|
|
|
uint32_t buf[sig_len / sizeof(uint32_t)];
|
|
|
|
memcpy(buf, sig, sig_len);
|
|
|
|
ret = pow_mod(key, buf);
|
|
if (ret)
|
|
return ret;
|
|
|
|
padding = algo->rsa_padding;
|
|
pad_len = algo->pad_len - algo->checksum_len;
|
|
|
|
/* Check pkcs1.5 padding bytes. */
|
|
if (memcmp(buf, padding, pad_len)) {
|
|
debug("In RSAVerify(): Padding check failed!\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Check hash. */
|
|
if (memcmp((uint8_t *)buf + pad_len, hash, sig_len - pad_len)) {
|
|
debug("In RSAVerify(): Hash check failed!\n");
|
|
return -EACCES;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void rsa_convert_big_endian(uint32_t *dst, const uint32_t *src, int len)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < len; i++)
|
|
dst[i] = fdt32_to_cpu(src[len - 1 - i]);
|
|
}
|
|
|
|
static int rsa_verify_with_keynode(struct image_sign_info *info,
|
|
const void *hash, uint8_t *sig, uint sig_len, int node)
|
|
{
|
|
const void *blob = info->fdt_blob;
|
|
struct rsa_public_key key;
|
|
const void *modulus, *rr;
|
|
int ret;
|
|
|
|
if (node < 0) {
|
|
debug("%s: Skipping invalid node", __func__);
|
|
return -EBADF;
|
|
}
|
|
if (!fdt_getprop(blob, node, "rsa,n0-inverse", NULL)) {
|
|
debug("%s: Missing rsa,n0-inverse", __func__);
|
|
return -EFAULT;
|
|
}
|
|
key.len = fdtdec_get_int(blob, node, "rsa,num-bits", 0);
|
|
key.n0inv = fdtdec_get_int(blob, node, "rsa,n0-inverse", 0);
|
|
modulus = fdt_getprop(blob, node, "rsa,modulus", NULL);
|
|
rr = fdt_getprop(blob, node, "rsa,r-squared", NULL);
|
|
if (!key.len || !modulus || !rr) {
|
|
debug("%s: Missing RSA key info", __func__);
|
|
return -EFAULT;
|
|
}
|
|
|
|
/* Sanity check for stack size */
|
|
if (key.len > RSA_MAX_KEY_BITS || key.len < RSA_MIN_KEY_BITS) {
|
|
debug("RSA key bits %u outside allowed range %d..%d\n",
|
|
key.len, RSA_MIN_KEY_BITS, RSA_MAX_KEY_BITS);
|
|
return -EFAULT;
|
|
}
|
|
key.len /= sizeof(uint32_t) * 8;
|
|
uint32_t key1[key.len], key2[key.len];
|
|
|
|
key.modulus = key1;
|
|
key.rr = key2;
|
|
rsa_convert_big_endian(key.modulus, modulus, key.len);
|
|
rsa_convert_big_endian(key.rr, rr, key.len);
|
|
if (!key.modulus || !key.rr) {
|
|
debug("%s: Out of memory", __func__);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
debug("key length %d\n", key.len);
|
|
ret = rsa_verify_key(&key, sig, sig_len, hash, info->algo->checksum);
|
|
if (ret) {
|
|
printf("%s: RSA failed to verify: %d\n", __func__, ret);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int rsa_verify(struct image_sign_info *info,
|
|
const struct image_region region[], int region_count,
|
|
uint8_t *sig, uint sig_len)
|
|
{
|
|
const void *blob = info->fdt_blob;
|
|
/* Reserve memory for maximum checksum-length */
|
|
uint8_t hash[info->algo->checksum->pad_len];
|
|
int ndepth, noffset;
|
|
int sig_node, node;
|
|
char name[100];
|
|
int ret;
|
|
|
|
/*
|
|
* Verify that the checksum-length does not exceed the
|
|
* rsa-signature-length
|
|
*/
|
|
if (info->algo->checksum->checksum_len >
|
|
info->algo->checksum->pad_len) {
|
|
debug("%s: invlaid checksum-algorithm %s for %s\n",
|
|
__func__, info->algo->checksum->name, info->algo->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME);
|
|
if (sig_node < 0) {
|
|
debug("%s: No signature node found\n", __func__);
|
|
return -ENOENT;
|
|
}
|
|
|
|
/* Calculate checksum with checksum-algorithm */
|
|
info->algo->checksum->calculate(region, region_count, hash);
|
|
|
|
/* See if we must use a particular key */
|
|
if (info->required_keynode != -1) {
|
|
ret = rsa_verify_with_keynode(info, hash, sig, sig_len,
|
|
info->required_keynode);
|
|
if (!ret)
|
|
return ret;
|
|
}
|
|
|
|
/* Look for a key that matches our hint */
|
|
snprintf(name, sizeof(name), "key-%s", info->keyname);
|
|
node = fdt_subnode_offset(blob, sig_node, name);
|
|
ret = rsa_verify_with_keynode(info, hash, sig, sig_len, node);
|
|
if (!ret)
|
|
return ret;
|
|
|
|
/* No luck, so try each of the keys in turn */
|
|
for (ndepth = 0, noffset = fdt_next_node(info->fit, sig_node, &ndepth);
|
|
(noffset >= 0) && (ndepth > 0);
|
|
noffset = fdt_next_node(info->fit, noffset, &ndepth)) {
|
|
if (ndepth == 1 && noffset != node) {
|
|
ret = rsa_verify_with_keynode(info, hash, sig, sig_len,
|
|
noffset);
|
|
if (!ret)
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|