6b13f685e
김민수
BSP 최초 추가
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#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))
#define RSA_DEFAULT_PUBEXP 65537
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;
}
}
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;
}
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);
}
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);
}
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;
}
static int is_public_exponent_bit_set(const struct rsa_public_key *key,
int pos)
{
return key->exponent & (1ULL << pos);
}
static int pow_mod(const struct rsa_public_key *key, uint32_t *inout)
{
uint32_t *result, *ptr;
uint i;
int j, k;
if (key->len > RSA_MAX_KEY_BITS / 32) {
debug("RSA key words %u exceeds maximum %d
", 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;
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)
",
k);
return -EINVAL;
}
if (!is_public_exponent_bit_set(key, 0)) {
debug("LSB of RSA public exponent must be set.
");
return -EINVAL;
}
montgomery_mul(key, acc, val, key->rr);
memcpy(a_scaled, acc, key->len * sizeof(a_scaled[0]));
for (j = k - 2; j > 0; --j) {
montgomery_mul(key, tmp, acc, acc);
if (is_public_exponent_bit_set(key, j)) {
montgomery_mul(key, acc, tmp, a_scaled);
} else {
memcpy(acc, tmp, key->len * sizeof(acc[0]));
}
}
montgomery_mul(key, tmp, acc, acc);
montgomery_mul(key, acc, tmp, val);
memcpy(result, acc, key->len * sizeof(result[0]));
if (greater_equal_modulus(key, result))
subtract_modulus(key, result);
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;
}
if (key.len > RSA_MAX_KEY_BITS || key.len < RSA_MIN_KEY_BITS) {
debug("RSA key bits %u outside allowed range %d..%d
",
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;
}
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