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 --- Changes in v5: Reverted change in rsa_mod_exp_sw function to add pointer to output length Addressed other comments by Simon
Changes in v4: Modified rsa_mod_exp_sw function to add pointer to output length
Changes in v3: Kconfig moved to separate patch. This patch just splits the file now
Changes in v2: Addressed few of Simon Glass's comments: - Kconfig option added for RSA - Comments added for new keyprop struct
include/u-boot/rsa-mod-exp.h | 43 ++++++ lib/rsa/Makefile | 2 +- lib/rsa/rsa-mod-exp.c | 303 +++++++++++++++++++++++++++++++++++++++ lib/rsa/rsa-verify.c | 329 ++++++++----------------------------------- tools/Makefile | 3 +- 5 files changed, 404 insertions(+), 276 deletions(-) create mode 100644 include/u-boot/rsa-mod-exp.h create mode 100644 lib/rsa/rsa-mod-exp.c
diff --git a/include/u-boot/rsa-mod-exp.h b/include/u-boot/rsa-mod-exp.h new file mode 100644 index 0000000..59cd9ea --- /dev/null +++ b/include/u-boot/rsa-mod-exp.h @@ -0,0 +1,43 @@ +/* + * Copyright (c) 2014, Ruchika Gupta. + * + * SPDX-License-Identifier: GPL-2.0+ +*/ + +#ifndef _RSA_MOD_EXP_H +#define _RSA_MOD_EXP_H + +#include <errno.h> +#include <image.h> + +/** + * struct key_prop - holder for a public key properties + * + * The struct has pointers to modulus (Typically called N), + * The inverse, R^2, exponent. These can be typecasted and + * used as byte arrays or converted to the required format + * as per requirement of RSA implementation. + */ +struct key_prop { + const void *rr; /* R^2 can be treated as byte array */ + const void *modulus; /* modulus as byte array */ + const void *public_exponent; /* public exponent as byte array */ + uint32_t n0inv; /* -1 / modulus[0] mod 2^32 */ + int num_bits; /* Key length in bits */ + uint32_t exp_len; /* Exponent length in number of uint8_t */ +}; + +/** + * rsa_mod_exp_sw() - Perform RSA Modular Exponentiation in sw + * + * Operation: out[] = sig ^ exponent % modulus + * + * @sig: RSA PKCS1.5 signature + * @sig_len: Length of signature in number of bytes + * @node: Node with RSA key elements like modulus, exponent, R^2, n0inv + * @out: Result in form of byte array + */ +int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len, + struct key_prop *node, uint8_t *out); + +#endif diff --git a/lib/rsa/Makefile b/lib/rsa/Makefile index a5a96cb6..cc25b3c 100644 --- a/lib/rsa/Makefile +++ b/lib/rsa/Makefile @@ -7,4 +7,4 @@ # SPDX-License-Identifier: GPL-2.0+ #
-obj-$(CONFIG_FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o +obj-$(CONFIG_FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o rsa-mod-exp.o diff --git a/lib/rsa/rsa-mod-exp.c b/lib/rsa/rsa-mod-exp.c new file mode 100644 index 0000000..4a6de2b --- /dev/null +++ b/lib/rsa/rsa-mod-exp.c @@ -0,0 +1,303 @@ +/* + * 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/rsa-mod-exp.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)) + +/* Default public exponent for backward compatibility */ +#define RSA_DEFAULT_PUBEXP 65537 + +/** + * 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[]) +{ + int i; + + for (i = (int)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); +} + +/** + * 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 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]); +} + +int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len, + struct key_prop *prop, uint8_t *out) +{ + struct rsa_public_key key; + int ret; + + if (!prop) { + debug("%s: Skipping invalid prop", __func__); + return -EBADF; + } + key.n0inv = prop->n0inv; + key.len = prop->num_bits; + + if (!prop->public_exponent) + key.exponent = RSA_DEFAULT_PUBEXP; + else + key.exponent = + fdt64_to_cpu(*((uint64_t *)(prop->public_exponent))); + + if (!key.len || !prop->modulus || !prop->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, (uint32_t *)prop->modulus, key.len); + rsa_convert_big_endian(key.rr, (uint32_t *)prop->rr, key.len); + if (!key.modulus || !key.rr) { + debug("%s: Out of memory", __func__); + return -ENOMEM; + } + + uint32_t buf[sig_len / sizeof(uint32_t)]; + + memcpy(buf, sig, sig_len); + + ret = pow_mod(&key, buf); + if (ret) + return ret; + + memcpy(out, buf, sig_len); + + return 0; +} diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c index 4ef19b6..f8bc086 100644 --- a/lib/rsa/rsa-verify.c +++ b/lib/rsa/rsa-verify.c @@ -17,230 +17,26 @@ #include "mkimage.h" #include <fdt_support.h> #endif +#include <u-boot/rsa-mod-exp.h> #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))
/* Default public exponent for backward compatibility */ #define RSA_DEFAULT_PUBEXP 65537
/** - * 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[]) -{ - int i; - - for (i = (int)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 + * rsa_verify_key() - Verify a signature against some data using RSA Key * - * @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); -} - -/** - * 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 + * Verify a RSA PKCS1.5 signature against an expected hash using + * the RSA Key properties in prop structure. * - * @key: RSA key - * @inout: Big-endian word array containing value and result + * @prop: Specifies key + * @sig: Signature + * @sig_len: Number of bytes in signature + * @hash: Pointer to the expected hash + * @algo: Checksum algo structure having information on RSA padding etc. + * @return 0 if verified, -ve on error */ -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)]; - - memcpy(buf, sig, sig_len); + uint8_t buf[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) { - 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->algo->checksum);
- return 0; + return ret; }
int rsa_verify(struct image_sign_info *info, diff --git a/tools/Makefile b/tools/Makefile index a4216a1..0b981da 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -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 \