rsa: Split the rsa-verify to separate the modular exponentiation
Public exponentiation which is required in rsa verify functionality is tightly integrated with verification code in rsa_verify.c. The patch splits the file into twp separating the modular exponentiation. 1. rsa-verify.c - The file parses device tree keys node to fill a keyprop structure. The keyprop structure can then be converted to implementation specific format. (struct rsa_pub_key for sw implementation) - The parsed device tree node is then passed to a generic rsa_mod_exp function. 2. rsa-mod-exp.c Move the software specific functions related to modular exponentiation from rsa-verify.c to this file. Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com> CC: Simon Glass <sjg@chromium.org> Acked-by: Simon Glass <sjg@chromium.org>utp
Ruchika Gupta
Simon Glass
parent
49cad54788
commit
fc2f4246b4
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@ -0,0 +1,43 @@
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/*
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* Copyright (c) 2014, Ruchika Gupta.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#ifndef _RSA_MOD_EXP_H
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#define _RSA_MOD_EXP_H
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#include <errno.h>
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#include <image.h>
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/**
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* struct key_prop - holder for a public key properties
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*
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* The struct has pointers to modulus (Typically called N),
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* The inverse, R^2, exponent. These can be typecasted and
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* used as byte arrays or converted to the required format
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* as per requirement of RSA implementation.
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*/
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struct key_prop {
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const void *rr; /* R^2 can be treated as byte array */
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const void *modulus; /* modulus as byte array */
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const void *public_exponent; /* public exponent as byte array */
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uint32_t n0inv; /* -1 / modulus[0] mod 2^32 */
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int num_bits; /* Key length in bits */
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uint32_t exp_len; /* Exponent length in number of uint8_t */
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};
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/**
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* rsa_mod_exp_sw() - Perform RSA Modular Exponentiation in sw
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*
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* Operation: out[] = sig ^ exponent % modulus
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*
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* @sig: RSA PKCS1.5 signature
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* @sig_len: Length of signature in number of bytes
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* @node: Node with RSA key elements like modulus, exponent, R^2, n0inv
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* @out: Result in form of byte array
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*/
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int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len,
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struct key_prop *node, uint8_t *out);
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#endif
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@ -7,4 +7,4 @@
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# SPDX-License-Identifier: GPL-2.0+
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#
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obj-$(CONFIG_FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o
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obj-$(CONFIG_FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o rsa-mod-exp.o
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@ -0,0 +1,303 @@
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/*
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* Copyright (c) 2013, Google Inc.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#ifndef USE_HOSTCC
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#include <common.h>
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#include <fdtdec.h>
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#include <asm/types.h>
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#include <asm/byteorder.h>
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#include <asm/errno.h>
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#include <asm/types.h>
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#include <asm/unaligned.h>
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#else
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#include "fdt_host.h"
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#include "mkimage.h"
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#include <fdt_support.h>
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#endif
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#include <u-boot/rsa.h>
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#include <u-boot/rsa-mod-exp.h>
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#define UINT64_MULT32(v, multby) (((uint64_t)(v)) * ((uint32_t)(multby)))
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#define get_unaligned_be32(a) fdt32_to_cpu(*(uint32_t *)a)
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#define put_unaligned_be32(a, b) (*(uint32_t *)(b) = cpu_to_fdt32(a))
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/* Default public exponent for backward compatibility */
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#define RSA_DEFAULT_PUBEXP 65537
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/**
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* subtract_modulus() - subtract modulus from the given value
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*
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* @key: Key containing modulus to subtract
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* @num: Number to subtract modulus from, as little endian word array
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*/
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static void subtract_modulus(const struct rsa_public_key *key, uint32_t num[])
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{
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int64_t acc = 0;
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uint i;
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for (i = 0; i < key->len; i++) {
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acc += (uint64_t)num[i] - key->modulus[i];
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num[i] = (uint32_t)acc;
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acc >>= 32;
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}
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}
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/**
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* greater_equal_modulus() - check if a value is >= modulus
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*
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* @key: Key containing modulus to check
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* @num: Number to check against modulus, as little endian word array
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* @return 0 if num < modulus, 1 if num >= modulus
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*/
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static int greater_equal_modulus(const struct rsa_public_key *key,
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uint32_t num[])
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{
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int i;
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for (i = (int)key->len - 1; i >= 0; i--) {
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if (num[i] < key->modulus[i])
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return 0;
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if (num[i] > key->modulus[i])
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return 1;
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}
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return 1; /* equal */
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}
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/**
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* montgomery_mul_add_step() - Perform montgomery multiply-add step
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*
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* Operation: montgomery result[] += a * b[] / n0inv % modulus
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*
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* @key: RSA key
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* @result: Place to put result, as little endian word array
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* @a: Multiplier
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* @b: Multiplicand, as little endian word array
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*/
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static void montgomery_mul_add_step(const struct rsa_public_key *key,
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uint32_t result[], const uint32_t a, const uint32_t b[])
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{
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uint64_t acc_a, acc_b;
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uint32_t d0;
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uint i;
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acc_a = (uint64_t)a * b[0] + result[0];
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d0 = (uint32_t)acc_a * key->n0inv;
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acc_b = (uint64_t)d0 * key->modulus[0] + (uint32_t)acc_a;
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for (i = 1; i < key->len; i++) {
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acc_a = (acc_a >> 32) + (uint64_t)a * b[i] + result[i];
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acc_b = (acc_b >> 32) + (uint64_t)d0 * key->modulus[i] +
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(uint32_t)acc_a;
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result[i - 1] = (uint32_t)acc_b;
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}
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acc_a = (acc_a >> 32) + (acc_b >> 32);
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result[i - 1] = (uint32_t)acc_a;
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if (acc_a >> 32)
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subtract_modulus(key, result);
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}
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/**
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* montgomery_mul() - Perform montgomery mutitply
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*
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* Operation: montgomery result[] = a[] * b[] / n0inv % modulus
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*
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* @key: RSA key
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* @result: Place to put result, as little endian word array
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* @a: Multiplier, as little endian word array
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* @b: Multiplicand, as little endian word array
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*/
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static void montgomery_mul(const struct rsa_public_key *key,
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uint32_t result[], uint32_t a[], const uint32_t b[])
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{
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uint i;
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for (i = 0; i < key->len; ++i)
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result[i] = 0;
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for (i = 0; i < key->len; ++i)
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montgomery_mul_add_step(key, result, a[i], b);
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}
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/**
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* num_pub_exponent_bits() - Number of bits in the public exponent
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*
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* @key: RSA key
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* @num_bits: Storage for the number of public exponent bits
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*/
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static int num_public_exponent_bits(const struct rsa_public_key *key,
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int *num_bits)
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{
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uint64_t exponent;
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int exponent_bits;
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const uint max_bits = (sizeof(exponent) * 8);
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exponent = key->exponent;
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exponent_bits = 0;
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if (!exponent) {
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*num_bits = exponent_bits;
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return 0;
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}
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for (exponent_bits = 1; exponent_bits < max_bits + 1; ++exponent_bits)
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if (!(exponent >>= 1)) {
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*num_bits = exponent_bits;
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return 0;
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}
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return -EINVAL;
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}
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/**
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* is_public_exponent_bit_set() - Check if a bit in the public exponent is set
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*
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* @key: RSA key
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* @pos: The bit position to check
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*/
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static int is_public_exponent_bit_set(const struct rsa_public_key *key,
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int pos)
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{
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return key->exponent & (1ULL << pos);
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}
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/**
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* pow_mod() - in-place public exponentiation
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*
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* @key: RSA key
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* @inout: Big-endian word array containing value and result
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*/
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static int pow_mod(const struct rsa_public_key *key, uint32_t *inout)
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{
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uint32_t *result, *ptr;
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uint i;
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int j, k;
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/* Sanity check for stack size - key->len is in 32-bit words */
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if (key->len > RSA_MAX_KEY_BITS / 32) {
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debug("RSA key words %u exceeds maximum %d\n", key->len,
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RSA_MAX_KEY_BITS / 32);
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return -EINVAL;
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}
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uint32_t val[key->len], acc[key->len], tmp[key->len];
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uint32_t a_scaled[key->len];
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result = tmp; /* Re-use location. */
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/* Convert from big endian byte array to little endian word array. */
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for (i = 0, ptr = inout + key->len - 1; i < key->len; i++, ptr--)
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val[i] = get_unaligned_be32(ptr);
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if (0 != num_public_exponent_bits(key, &k))
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return -EINVAL;
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if (k < 2) {
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debug("Public exponent is too short (%d bits, minimum 2)\n",
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k);
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return -EINVAL;
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}
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if (!is_public_exponent_bit_set(key, 0)) {
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debug("LSB of RSA public exponent must be set.\n");
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return -EINVAL;
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}
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/* the bit at e[k-1] is 1 by definition, so start with: C := M */
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montgomery_mul(key, acc, val, key->rr); /* acc = a * RR / R mod n */
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/* retain scaled version for intermediate use */
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memcpy(a_scaled, acc, key->len * sizeof(a_scaled[0]));
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for (j = k - 2; j > 0; --j) {
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montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod n */
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if (is_public_exponent_bit_set(key, j)) {
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/* acc = tmp * val / R mod n */
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montgomery_mul(key, acc, tmp, a_scaled);
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} else {
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/* e[j] == 0, copy tmp back to acc for next operation */
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memcpy(acc, tmp, key->len * sizeof(acc[0]));
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}
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}
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/* the bit at e[0] is always 1 */
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montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod n */
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montgomery_mul(key, acc, tmp, val); /* acc = tmp * a / R mod M */
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memcpy(result, acc, key->len * sizeof(result[0]));
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/* Make sure result < mod; result is at most 1x mod too large. */
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if (greater_equal_modulus(key, result))
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subtract_modulus(key, result);
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/* Convert to bigendian byte array */
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for (i = key->len - 1, ptr = inout; (int)i >= 0; i--, ptr++)
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put_unaligned_be32(result[i], ptr);
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return 0;
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}
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static void rsa_convert_big_endian(uint32_t *dst, const uint32_t *src, int len)
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{
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int i;
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for (i = 0; i < len; i++)
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dst[i] = fdt32_to_cpu(src[len - 1 - i]);
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}
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int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len,
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struct key_prop *prop, uint8_t *out)
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{
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struct rsa_public_key key;
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int ret;
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if (!prop) {
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debug("%s: Skipping invalid prop", __func__);
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return -EBADF;
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}
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key.n0inv = prop->n0inv;
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key.len = prop->num_bits;
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if (!prop->public_exponent)
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key.exponent = RSA_DEFAULT_PUBEXP;
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else
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key.exponent =
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fdt64_to_cpu(*((uint64_t *)(prop->public_exponent)));
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if (!key.len || !prop->modulus || !prop->rr) {
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debug("%s: Missing RSA key info", __func__);
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return -EFAULT;
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}
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/* Sanity check for stack size */
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if (key.len > RSA_MAX_KEY_BITS || key.len < RSA_MIN_KEY_BITS) {
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debug("RSA key bits %u outside allowed range %d..%d\n",
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key.len, RSA_MIN_KEY_BITS, RSA_MAX_KEY_BITS);
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return -EFAULT;
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}
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key.len /= sizeof(uint32_t) * 8;
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uint32_t key1[key.len], key2[key.len];
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key.modulus = key1;
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key.rr = key2;
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rsa_convert_big_endian(key.modulus, (uint32_t *)prop->modulus, key.len);
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rsa_convert_big_endian(key.rr, (uint32_t *)prop->rr, key.len);
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if (!key.modulus || !key.rr) {
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debug("%s: Out of memory", __func__);
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return -ENOMEM;
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}
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uint32_t buf[sig_len / sizeof(uint32_t)];
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memcpy(buf, sig, sig_len);
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ret = pow_mod(&key, buf);
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if (ret)
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return ret;
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memcpy(out, buf, sig_len);
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return 0;
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}
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@ -17,230 +17,26 @@
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#include "mkimage.h"
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#include <fdt_support.h>
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#endif
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#include <u-boot/rsa-mod-exp.h>
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#include <u-boot/rsa.h>
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#include <u-boot/sha1.h>
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#include <u-boot/sha256.h>
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#define UINT64_MULT32(v, multby) (((uint64_t)(v)) * ((uint32_t)(multby)))
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#define get_unaligned_be32(a) fdt32_to_cpu(*(uint32_t *)a)
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#define put_unaligned_be32(a, b) (*(uint32_t *)(b) = cpu_to_fdt32(a))
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/* Default public exponent for backward compatibility */
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#define RSA_DEFAULT_PUBEXP 65537
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/**
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* subtract_modulus() - subtract modulus from the given value
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* rsa_verify_key() - Verify a signature against some data using RSA Key
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*
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* @key: Key containing modulus to subtract
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* @num: Number to subtract modulus from, as little endian word array
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* Verify a RSA PKCS1.5 signature against an expected hash using
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* the RSA Key properties in prop structure.
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*
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* @prop: Specifies key
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* @sig: Signature
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* @sig_len: Number of bytes in signature
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* @hash: Pointer to the expected hash
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* @algo: Checksum algo structure having information on RSA padding etc.
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* @return 0 if verified, -ve on error
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*/
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static void subtract_modulus(const struct rsa_public_key *key, uint32_t num[])
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{
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int64_t acc = 0;
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uint i;
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for (i = 0; i < key->len; i++) {
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acc += (uint64_t)num[i] - key->modulus[i];
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num[i] = (uint32_t)acc;
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acc >>= 32;
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}
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}
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/**
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* greater_equal_modulus() - check if a value is >= modulus
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*
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* @key: Key containing modulus to check
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* @num: Number to check against modulus, as little endian word array
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* @return 0 if num < modulus, 1 if num >= modulus
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*/
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static int greater_equal_modulus(const struct rsa_public_key *key,
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uint32_t num[])
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{
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int i;
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for (i = (int)key->len - 1; i >= 0; i--) {
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if (num[i] < key->modulus[i])
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return 0;
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if (num[i] > key->modulus[i])
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return 1;
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}
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return 1; /* equal */
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}
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/**
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* montgomery_mul_add_step() - Perform montgomery multiply-add step
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*
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* Operation: montgomery result[] += a * b[] / n0inv % modulus
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*
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* @key: RSA key
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* @result: Place to put result, as little endian word array
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* @a: Multiplier
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* @b: Multiplicand, as little endian word array
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*/
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static void montgomery_mul_add_step(const struct rsa_public_key *key,
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uint32_t result[], const uint32_t a, const uint32_t b[])
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{
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uint64_t acc_a, acc_b;
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uint32_t d0;
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uint i;
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acc_a = (uint64_t)a * b[0] + result[0];
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d0 = (uint32_t)acc_a * key->n0inv;
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acc_b = (uint64_t)d0 * key->modulus[0] + (uint32_t)acc_a;
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for (i = 1; i < key->len; i++) {
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acc_a = (acc_a >> 32) + (uint64_t)a * b[i] + result[i];
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acc_b = (acc_b >> 32) + (uint64_t)d0 * key->modulus[i] +
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(uint32_t)acc_a;
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result[i - 1] = (uint32_t)acc_b;
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}
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|
||||
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);
|
||||
}
|
||||
|
||||
/**
|
||||
* 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
|
||||
*
|
||||
* @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;
|
||||
int j, k;
|
||||
|
||||
/* 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];
|
||||
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);
|
||||
|
||||
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]));
|
||||
}
|
||||
}
|
||||
|
||||
/* 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))
|
||||
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)
|
||||
{
|
||||
|
|
@ -248,10 +44,10 @@ static int rsa_verify_key(const struct rsa_public_key *key, const uint8_t *sig,
|
|||
int pad_len;
|
||||
int ret;
|
||||
|
||||
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;
|
||||
}
|
||||
|
|
@ -265,13 +61,13 @@ static int rsa_verify_key(const struct rsa_public_key *key, const uint8_t *sig,
|
|||
return -EINVAL;
|
||||
}
|
||||
|
||||
uint32_t buf[sig_len / sizeof(uint32_t)];
|
||||
uint8_t buf[sig_len];
|
||||
|
||||
memcpy(buf, sig, sig_len);
|
||||
|
||||
ret = pow_mod(key, buf);
|
||||
if (ret)
|
||||
ret = rsa_mod_exp_sw(sig, sig_len, prop, buf);
|
||||
if (ret) {
|
||||
debug("Error in Modular exponentation\n");
|
||||
return ret;
|
||||
}
|
||||
|
||||
padding = algo->rsa_padding;
|
||||
pad_len = algo->pad_len - algo->checksum_len;
|
||||
|
|
@ -291,72 +87,57 @@ static int rsa_verify_key(const struct rsa_public_key *key, const uint8_t *sig,
|
|||
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;
|
||||
const uint64_t *public_exponent;
|
||||
struct key_prop prop;
|
||||
int length;
|
||||
int ret;
|
||||
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);
|
||||
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) {
|
||||
|
||||
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;
|
||||
}
|
||||
|
||||
/* 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];
|
||||
ret = rsa_verify_key(&prop, sig, sig_len, hash, info->algo->checksum);
|
||||
|
||||
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;
|
||||
return ret;
|
||||
}
|
||||
|
||||
int rsa_verify(struct image_sign_info *info,
|
||||
|
|
|
|||
|
|
@ -60,7 +60,8 @@ FIT_SIG_OBJS-$(CONFIG_FIT_SIGNATURE) := common/image-sig.o
|
|||
LIBFDT_OBJS := $(addprefix lib/libfdt/, \
|
||||
fdt.o fdt_ro.o fdt_rw.o fdt_strerror.o fdt_wip.o)
|
||||
RSA_OBJS-$(CONFIG_FIT_SIGNATURE) := $(addprefix lib/rsa/, \
|
||||
rsa-sign.o rsa-verify.o rsa-checksum.o)
|
||||
rsa-sign.o rsa-verify.o rsa-checksum.o \
|
||||
rsa-mod-exp.o)
|
||||
|
||||
# common objs for dumpimage and mkimage
|
||||
dumpimage-mkimage-objs := aisimage.o \
|
||||
|
|
|
|||
Loading…
Reference in New Issue