Implement BootConfig.

This commit is contained in:
Michael Scire 2018-02-27 20:28:34 -08:00
parent d0b74d7751
commit c5b0639b8a
6 changed files with 159 additions and 76 deletions

View file

@ -340,6 +340,63 @@ void se_get_exp_mod_output(void *buf, size_t size) {
}
}
bool se_rsa2048_pss_verify(const void *signature, size_t signature_size, const void *modulus, size_t modulus_size, const void *data, size_t data_size) {
uint8_t message[RSA_2048_BYTES];
uint8_t h_buf[0x24];
/* Hardcode RSA with keyslot 0. */
const uint8_t public_exponent[4] = {0x00, 0x01, 0x00, 0x01};
set_rsa_keyslot(0, modulus, modulus_size, public_exponent, sizeof(public_exponent));
se_synchronous_exp_mod(0, message, sizeof(message), signature, signature_size);
/* Validate sanity byte. */
if (message[RSA_2048_BYTES - 1] != 0xBC) {
return false;
}
/* Copy Salt into MGF1 Hash Buffer. */
memset(h_buf, 0, sizeof(h_buf));
memcpy(h_buf, message + RSA_2048_BYTES - 0x20 - 0x1, 0x20);
/* Decrypt maskedDB (via inline MGF1). */
uint8_t seed = 0;
uint8_t mgf1_buf[0x20];
for (unsigned int ofs = 0; ofs < RSA_2048_BYTES - 0x20 - 1; ofs += 0x20) {
h_buf[sizeof(h_buf) - 1] = seed++;
flush_dcache_range(h_buf, h_buf + sizeof(h_buf));
se_calculate_sha256(mgf1_buf, h_buf, sizeof(h_buf));
for (unsigned int i = ofs; i < ofs + 0x20 && i < RSA_2048_BYTES - 0x20 - 1; i++) {
message[i] ^= mgf1_buf[i - ofs];
}
}
/* Constant lmask for rsa-2048-pss. */
message[0] &= 0x7F;
/* Validate DB is of the form 0000...0001. */
for (unsigned int i = 0; i < RSA_2048_BYTES - 0x20 - 0x20 - 1 - 1; i++) {
if (message[i] != 0) {
return false;
}
}
if (message[RSA_2048_BYTES - 0x20 - 0x20 - 1 - 1] != 1) {
return false;
}
/* Check hash correctness. */
uint8_t validate_buf[8 + 0x20 + 0x20];
uint8_t validate_hash[0x20];
memset(validate_buf, 0, sizeof(validate_buf));
flush_dcache_range((uint8_t *)data, (uint8_t *)data + data_size);
se_calculate_sha256(&validate_buf[8], data, data_size);
memcpy(&validate_buf[0x28], &message[RSA_2048_BYTES - 0x20 - 0x20 - 1], 0x20);
flush_dcache_range(validate_buf, validate_buf + sizeof(validate_buf));
se_calculate_sha256(validate_hash, validate_buf, sizeof(validate_buf));
return memcmp(h_buf, validate_hash, 0x20) == 0;
}
void trigger_se_rsa_op(void *buf, size_t size) {
se_ll_t in_ll;
ll_init(&in_ll, (void *)buf, size);