+// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2013, Google Inc.
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
+#ifndef USE_HOSTCC
#include <common.h>
#include <fdtdec.h>
-#include <rsa.h>
-#include <sha1.h>
-#include <sha256.h>
+#include <asm/types.h>
#include <asm/byteorder.h>
-#include <asm/errno.h>
+#include <linux/errno.h>
+#include <asm/types.h>
#include <asm/unaligned.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
-
-/**
- * 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 */
-}
+#include <dm.h>
+#else
+#include "fdt_host.h"
+#include "mkimage.h"
+#include <fdt_support.h>
+#endif
+#include <u-boot/rsa-mod-exp.h>
+#include <u-boot/rsa.h>
+
+/* Default public exponent for backward compatibility */
+#define RSA_DEFAULT_PUBEXP 65537
/**
- * montgomery_mul_add_step() - Perform montgomery multiply-add step
+ * rsa_verify_padding() - Verify RSA message padding is valid
*
- * Operation: montgomery result[] += a * b[] / n0inv % modulus
+ * Verify a RSA message's padding is consistent with PKCS1.5
+ * padding as described in the RSA PKCS#1 v2.1 standard.
*
- * @key: RSA key
- * @result: Place to put result, as little endian word array
- * @a: Multiplier
- * @b: Multiplicand, as little endian word array
+ * @msg: Padded message
+ * @pad_len: Number of expected padding bytes
+ * @algo: Checksum algo structure having information on DER encoding etc.
+ * @return 0 on success, != 0 on failure
*/
-static void montgomery_mul_add_step(const struct rsa_public_key *key,
- uint32_t result[], const uint32_t a, const uint32_t b[])
+static int rsa_verify_padding(const uint8_t *msg, const int pad_len,
+ struct checksum_algo *algo)
{
- 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);
+ int ff_len;
+ int ret;
- result[i - 1] = (uint32_t)acc_a;
+ /* first byte must be 0x00 */
+ ret = *msg++;
+ /* second byte must be 0x01 */
+ ret |= *msg++ ^ 0x01;
+ /* next ff_len bytes must be 0xff */
+ ff_len = pad_len - algo->der_len - 3;
+ ret |= *msg ^ 0xff;
+ ret |= memcmp(msg, msg+1, ff_len-1);
+ msg += ff_len;
+ /* next byte must be 0x00 */
+ ret |= *msg++;
+ /* next der_len bytes must match der_prefix */
+ ret |= memcmp(msg, algo->der_prefix, algo->der_len);
- if (acc_a >> 32)
- subtract_modulus(key, result);
+ return ret;
}
/**
- * montgomery_mul() - Perform montgomery mutitply
+ * rsa_verify_key() - Verify a signature against some data using RSA Key
*
- * Operation: montgomery result[] = a[] * b[] / n0inv % modulus
+ * Verify a RSA PKCS1.5 signature against an expected hash using
+ * the RSA Key properties in prop structure.
*
- * @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
+ * @prop: Specifies key
+ * @sig: Signature
+ * @sig_len: Number of bytes in signature
+ * @hash: Pointer to the expected hash
+ * @key_len: Number of bytes in rsa key
+ * @algo: Checksum algo structure having information on DER encoding etc.
+ * @return 0 if verified, -ve on error
*/
-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,
+static int rsa_verify_key(struct key_prop *prop, const uint8_t *sig,
const uint32_t sig_len, const uint8_t *hash,
- struct checksum_algo *algo)
+ const uint32_t key_len, struct checksum_algo *algo)
{
- const uint8_t *padding;
int pad_len;
int ret;
+#if !defined(USE_HOSTCC)
+ struct udevice *mod_exp_dev;
+#endif
- if (!key || !sig || !hash || !algo)
+ if (!prop || !sig || !hash || !algo)
return -EIO;
- if (sig_len != (key->len * sizeof(uint32_t))) {
+ if (sig_len != (prop->num_bits / 8)) {
debug("Signature is of incorrect length %d\n", sig_len);
return -EINVAL;
}
return -EINVAL;
}
- uint32_t buf[sig_len / sizeof(uint32_t)];
+ uint8_t buf[sig_len];
- memcpy(buf, sig, sig_len);
+#if !defined(USE_HOSTCC)
+ ret = uclass_get_device(UCLASS_MOD_EXP, 0, &mod_exp_dev);
+ if (ret) {
+ printf("RSA: Can't find Modular Exp implementation\n");
+ return -EINVAL;
+ }
- ret = pow_mod(key, buf);
- if (ret)
+ ret = rsa_mod_exp(mod_exp_dev, sig, sig_len, prop, buf);
+#else
+ ret = rsa_mod_exp_sw(sig, sig_len, prop, buf);
+#endif
+ if (ret) {
+ debug("Error in Modular exponentation\n");
return ret;
+ }
- padding = algo->rsa_padding;
- pad_len = RSA2048_BYTES - algo->checksum_len;
+ pad_len = key_len - algo->checksum_len;
/* Check pkcs1.5 padding bytes. */
- if (memcmp(buf, padding, pad_len)) {
+ ret = rsa_verify_padding(buf, pad_len, algo);
+ if (ret) {
debug("In RSAVerify(): Padding check failed!\n");
return -EINVAL;
}
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]);
-}
-
+/**
+ * rsa_verify_with_keynode() - Verify a signature against some data using
+ * information in node with prperties of RSA Key like modulus, exponent etc.
+ *
+ * Parse sign-node and fill a key_prop structure with properties of the
+ * key. Verify a RSA PKCS1.5 signature against an expected hash using
+ * the properties parsed
+ *
+ * @info: Specifies key and FIT information
+ * @hash: Pointer to the expected hash
+ * @sig: Signature
+ * @sig_len: Number of bytes in signature
+ * @node: Node having the RSA Key properties
+ * @return 0 if verified, -ve on error
+ */
static int rsa_verify_with_keynode(struct image_sign_info *info,
- const void *hash, uint8_t *sig, uint sig_len, int node)
+ 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;
+ struct key_prop prop;
+ int length;
+ int ret = 0;
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);
+ prop.num_bits = fdtdec_get_int(blob, node, "rsa,num-bits", 0);
+
+ prop.n0inv = fdtdec_get_int(blob, node, "rsa,n0-inverse", 0);
+
+ prop.public_exponent = fdt_getprop(blob, node, "rsa,exponent", &length);
+ if (!prop.public_exponent || length < sizeof(uint64_t))
+ prop.public_exponent = NULL;
+
+ prop.exp_len = sizeof(uint64_t);
+
+ prop.modulus = fdt_getprop(blob, node, "rsa,modulus", NULL);
+
+ prop.rr = fdt_getprop(blob, node, "rsa,r-squared", NULL);
+
+ if (!prop.num_bits || !prop.modulus) {
+ debug("%s: Missing RSA key info", __func__);
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;
- }
+ ret = rsa_verify_key(&prop, sig, sig_len, hash,
+ info->crypto->key_len, info->checksum);
- return 0;
+ return ret;
}
int rsa_verify(struct image_sign_info *info,
{
const void *blob = info->fdt_blob;
/* Reserve memory for maximum checksum-length */
- uint8_t hash[RSA2048_BYTES];
+ uint8_t hash[info->crypto->key_len];
int ndepth, noffset;
int sig_node, node;
char name[100];
* Verify that the checksum-length does not exceed the
* rsa-signature-length
*/
- if (info->algo->checksum->checksum_len > RSA2048_BYTES) {
- debug("%s: invlaid checksum-algorithm %s for RSA2048\n",
- __func__, info->algo->checksum->name);
+ if (info->checksum->checksum_len >
+ info->crypto->key_len) {
+ debug("%s: invlaid checksum-algorithm %s for %s\n",
+ __func__, info->checksum->name, info->crypto->name);
return -EINVAL;
}
}
/* Calculate checksum with checksum-algorithm */
- info->algo->checksum->calculate(region, region_count, hash);
+ ret = info->checksum->calculate(info->checksum->name,
+ region, region_count, hash);
+ if (ret < 0) {
+ debug("%s: Error in checksum calculation\n", __func__);
+ return -EINVAL;
+ }
/* See if we must use a particular key */
if (info->required_keynode != -1) {
projects / platform / kernel / u-boot.git / blobdiff