* SPDX-License-Identifier: GPL-2.0+
*/
+#ifndef USE_HOSTCC
#include <common.h>
#include <fdtdec.h>
-#include <rsa.h>
-#include <sha1.h>
+#include <asm/types.h>
#include <asm/byteorder.h>
#include <asm/errno.h>
+#include <asm/types.h>
#include <asm/unaligned.h>
-
-/**
- * struct rsa_public_key - holder for a public key
- *
- * An RSA public key consists of a modulus (typically called N), the inverse
- * and R^2, where R is 2^(# key bits).
- */
-struct rsa_public_key {
- uint len; /* Length of modulus[] in number of uint32_t */
- uint32_t n0inv; /* -1 / modulus[0] mod 2^32 */
- uint32_t *modulus; /* modulus as little endian array */
- uint32_t *rr; /* R^2 as little endian array */
-};
+#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 RSA2048_BYTES (2048 / 8)
-
-/* This is the minimum/maximum key size we support, in bits */
-#define RSA_MIN_KEY_BITS 2048
-#define RSA_MAX_KEY_BITS 2048
-
-/* This is the maximum signature length that we support, in bits */
-#define RSA_MAX_SIG_BITS 2048
-
-static const uint8_t padding_sha1_rsa2048[RSA2048_BYTES - SHA1_SUM_LEN] = {
- 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x21, 0x30,
- 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a,
- 0x05, 0x00, 0x04, 0x14
-};
+#define get_unaligned_be32(a) fdt32_to_cpu(*(uint32_t *)a)
+#define put_unaligned_be32(a, b) (*(uint32_t *)(b) = cpu_to_fdt32(a))
+
+/* Default public exponent for backward compatibility */
+#define RSA_DEFAULT_PUBEXP 65537
/**
* subtract_modulus() - subtract modulus from the given value
static int greater_equal_modulus(const struct rsa_public_key *key,
uint32_t num[])
{
- uint32_t i;
+ int i;
- for (i = key->len - 1; i >= 0; i--) {
+ for (i = (int)key->len - 1; i >= 0; i--) {
if (num[i] < key->modulus[i])
return 0;
if (num[i] > key->modulus[i])
montgomery_mul_add_step(key, result, a[i], b);
}
+/**
+ * num_pub_exponent_bits() - Number of bits in the public exponent
+ *
+ * @key: RSA key
+ * @num_bits: Storage for the number of public exponent bits
+ */
+static int num_public_exponent_bits(const struct rsa_public_key *key,
+ int *num_bits)
+{
+ uint64_t exponent;
+ int exponent_bits;
+ const uint max_bits = (sizeof(exponent) * 8);
+
+ exponent = key->exponent;
+ exponent_bits = 0;
+
+ if (!exponent) {
+ *num_bits = exponent_bits;
+ return 0;
+ }
+
+ for (exponent_bits = 1; exponent_bits < max_bits + 1; ++exponent_bits)
+ if (!(exponent >>= 1)) {
+ *num_bits = exponent_bits;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * is_public_exponent_bit_set() - Check if a bit in the public exponent is set
+ *
+ * @key: RSA key
+ * @pos: The bit position to check
+ */
+static int is_public_exponent_bit_set(const struct rsa_public_key *key,
+ int pos)
+{
+ return key->exponent & (1ULL << pos);
+}
+
/**
* pow_mod() - in-place public exponentiation
*
{
uint32_t *result, *ptr;
uint i;
+ int j, k;
/* Sanity check for stack size - key->len is in 32-bit words */
if (key->len > RSA_MAX_KEY_BITS / 32) {
}
uint32_t val[key->len], acc[key->len], tmp[key->len];
+ uint32_t a_scaled[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 */
+ if (0 != num_public_exponent_bits(key, &k))
+ return -EINVAL;
+
+ if (k < 2) {
+ debug("Public exponent is too short (%d bits, minimum 2)\n",
+ k);
+ return -EINVAL;
+ }
+
+ if (!is_public_exponent_bit_set(key, 0)) {
+ debug("LSB of RSA public exponent must be set.\n");
+ return -EINVAL;
+ }
+
+ /* the bit at e[k-1] is 1 by definition, so start with: C := M */
+ montgomery_mul(key, acc, val, key->rr); /* acc = a * RR / R mod n */
+ /* retain scaled version for intermediate use */
+ memcpy(a_scaled, acc, key->len * sizeof(a_scaled[0]));
+
+ for (j = k - 2; j > 0; --j) {
+ montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod n */
+
+ if (is_public_exponent_bit_set(key, j)) {
+ /* acc = tmp * val / R mod n */
+ montgomery_mul(key, acc, tmp, a_scaled);
+ } else {
+ /* e[j] == 0, copy tmp back to acc for next operation */
+ memcpy(acc, tmp, key->len * sizeof(acc[0]));
+ }
}
- montgomery_mul(key, result, acc, val); /* result = XX * a / R mod M */
+
+ /* the bit at e[0] is always 1 */
+ montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod n */
+ montgomery_mul(key, acc, tmp, val); /* acc = tmp * a / R mod M */
+ memcpy(result, acc, key->len * sizeof(result[0]));
/* Make sure result < mod; result is at most 1x mod too large. */
if (greater_equal_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)
+ 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)
+ if (!key || !sig || !hash || !algo)
return -EIO;
if (sig_len != (key->len * sizeof(uint32_t))) {
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,
if (ret)
return ret;
- /* Determine padding to use depending on the signature type. */
- padding = padding_sha1_rsa2048;
- pad_len = RSA2048_BYTES - SHA1_SUM_LEN;
+ padding = algo->rsa_padding;
+ pad_len = algo->pad_len - algo->checksum_len;
/* Check pkcs1.5 padding bytes. */
if (memcmp(buf, padding, pad_len)) {
const void *blob = info->fdt_blob;
struct rsa_public_key key;
const void *modulus, *rr;
+ const uint64_t *public_exponent;
+ int length;
int ret;
if (node < 0) {
}
key.len = fdtdec_get_int(blob, node, "rsa,num-bits", 0);
key.n0inv = fdtdec_get_int(blob, node, "rsa,n0-inverse", 0);
+ public_exponent = fdt_getprop(blob, node, "rsa,exponent", &length);
+ if (!public_exponent || length < sizeof(*public_exponent))
+ key.exponent = RSA_DEFAULT_PUBEXP;
+ else
+ key.exponent = fdt64_to_cpu(*public_exponent);
modulus = fdt_getprop(blob, node, "rsa,modulus", NULL);
rr = fdt_getprop(blob, node, "rsa,r-squared", NULL);
if (!key.len || !modulus || !rr) {
}
debug("key length %d\n", key.len);
- ret = rsa_verify_key(&key, sig, sig_len, hash);
+ 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;
uint8_t *sig, uint sig_len)
{
const void *blob = info->fdt_blob;
- uint8_t hash[SHA1_SUM_LEN];
+ /* Reserve memory for maximum checksum-length */
+ uint8_t hash[info->algo->checksum->pad_len];
int ndepth, noffset;
int sig_node, node;
char name[100];
- sha1_context ctx;
- int ret, i;
+ 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) {
return -ENOENT;
}
- sha1_starts(&ctx);
- for (i = 0; i < region_count; i++)
- sha1_update(&ctx, region[i].data, region[i].size);
- sha1_finish(&ctx, hash);
+ /* 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) {
projects / karo-tx-uboot.git / blobdiff