/*
* mgmt-misc.c
* -----------
* Miscellaneous CLI functions.
*
* Copyright (c) 2016, NORDUnet A/S All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the NORDUnet nor the names of its contributors may
* be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* Rename both CMSIS HAL_OK and libhal HAL_OK to disambiguate */
#define HAL_OK CMSIS_HAL_OK
#include "stm-init.h"
#include "stm-uart.h"
#include "sdram-malloc.h"
#include "mgmt-cli.h"
#include "mgmt-misc.h"
#undef HAL_OK
#define HAL_OK LIBHAL_OK
#include "hal.h"
#include "hal_internal.h"
#include "cryptech_signing_key.h"
#undef HAL_OK
#include <string.h>
#define pad(n, sz) (((n) + (sz-1)) & ~(sz-1))
static hal_error_t verify_signature(const uint8_t * const data,
const size_t data_len,
const uint8_t * const signature,
const size_t signature_len)
{
hal_error_t err;
const hal_core_t *core = NULL;
const hal_hash_descriptor_t * const descriptor = hal_hash_sha256;
hal_hash_state_t *state = NULL;
uint8_t statebuf[descriptor->hash_state_length];
uint8_t digest[signature_len];
#if 1
/* HACK - find the second sha256 core, to avoid interfering with rpc.
* If there isn't a second one, this will set core to NULL, and
* hal_hash_initialize will find the first one.
*/
core = hal_core_find(descriptor->core_name, core);
core = hal_core_find(descriptor->core_name, core);
#endif
if ((err = hal_hash_initialize(core, descriptor, &state, statebuf, sizeof(statebuf))) != LIBHAL_OK ||
(err = hal_hash_update(state, data, data_len)) != LIBHAL_OK ||
(err = hal_hash_finalize(state, digest, sizeof(digest))) != LIBHAL_OK)
return err;
const uint8_t name[] = "Cryptech signing key";
const size_t name_len = sizeof(name);
uint8_t der[65]; /* ?? */
int ks_hint;
if ((err = hal_ks_fetch(HAL_KEY_TYPE_EC_PUBLIC, name, name_len, NULL, NULL, der, NULL, sizeof(der), &ks_hint)) != LIBHAL_OK)
/* get the built-in signing key */
memcpy(der, cryptech_signing_key, sizeof(der));
uint8_t keybuf[hal_ecdsa_key_t_size];
hal_ecdsa_key_t *key = NULL;
if ((err = hal_ecdsa_public_key_from_der(&key, keybuf, sizeof(keybuf), der, sizeof(der))) != LIBHAL_OK ||
(err = hal_ecdsa_verify(NULL, key, digest, sizeof(digest), signature, signature_len)) != LIBHAL_OK)
return err;
return LIBHAL_OK;
}
int cli_receive_data(struct cli_def *cli, uint8_t **filebuf, size_t *file_len, size_t chunksize)
{
uint32_t filesize = 0, counter = 0;
uint8_t *writeptr;
size_t n = chunksize;
if (! control_mgmt_uart_dma_rx(DMA_RX_STOP)) {
cli_print(cli, "Failed stopping DMA");
return CLI_OK;
}
cli_print(cli, "OK, write size (4 bytes), data in %li byte chunks", (uint32_t) n);
if (uart_receive_bytes(STM_UART_MGMT, (void *) &filesize, 4, 1000) != CMSIS_HAL_OK) {
cli_print(cli, "Receive timed out");
return CLI_ERROR;
}
*file_len = (size_t)(pad(filesize, chunksize));
if ((*filebuf = sdram_malloc(*file_len)) == NULL) {
cli_print(cli, "File buffer allocation failed");
return CLI_ERROR;
}
/* By initializing buf to the same value that erased flash has (0xff), we don't
* have to try and be smart when writing the last page of data to a flash memory.
*/
memset(*filebuf, 0xff, *file_len);
writeptr = *filebuf;
cli_print(cli, "Send %li bytes of data", filesize);
while (filesize) {
if (filesize < n) n = filesize;
if (uart_receive_bytes(STM_UART_MGMT, (void *) writeptr, n, 1000) != CMSIS_HAL_OK) {
cli_print(cli, "Receive timed out");
goto errout;
}
writeptr += n;
filesize -= n;
counter++;
uart_send_bytes(STM_UART_MGMT, (void *) &counter, 4);
}
uint32_t sigsize;
cli_print(cli, "Send signature size (4 bytes)");
if (uart_receive_bytes(STM_UART_MGMT, (void *) &sigsize, 4, 1000) != CMSIS_HAL_OK) {
cli_print(cli, "Receive timed out");
goto errout;
}
if (sigsize < 70 || sigsize > 72) {
cli_print(cli, "Unexpected signature size %d, expected 70-72", (int)sigsize);
goto errout;
}
uint8_t sigbuf[72];
cli_print(cli, "Send %li bytes of data", sigsize);
if (uart_receive_bytes(STM_UART_MGMT, (void *) sigbuf, sigsize, 1000) != CMSIS_HAL_OK) {
cli_print(cli, "Receive timed out");
goto errout;
}
/* Signature is in DER format: sequence of 2 integers. Decode into
* what ecdsa expects: an octet string consisting of concatenated
* values for r and s, each of which occupies half of the octet string.
*/
/* XXX should use the asn1 decoder, but just going to hack this for now */
int i = 0;
#define ASN1_SEQUENCE 0x30
#define ASN1_INTEGER 0x02
if (sigbuf[i++] != ASN1_SEQUENCE) {
cli_print(cli, "Error parsing signature");
goto errout;
}
i++;
if (sigbuf[i++] != ASN1_INTEGER) {
cli_print(cli, "Error parsing signature");
goto errout;
}
if (sigbuf[i++] == 0x21) i++;
memmove(&sigbuf[0], &sigbuf[i], 32);
i += 32;
if (sigbuf[i++] != ASN1_INTEGER) {
cli_print(cli, "Error parsing signature");
goto errout;
}
if (sigbuf[i++] == 0x21) i++;
memmove(&sigbuf[32], &sigbuf[i], 32);
if (verify_signature(*filebuf, *file_len, sigbuf, 64) != LIBHAL_OK) {
cli_print(cli, "Signature verification FAILED");
goto errout;
}
cli_print(cli, "Signature verification SUCCEEDED");
return CLI_OK;
errout:
sdram_free(*filebuf);
*filebuf = NULL;
*file_len = 0;
return CLI_ERROR;
}
static int cmd_reboot(struct cli_def *cli, const char *command, char *argv[], int argc)
{
cli_print(cli, "\n\n\nRebooting\n\n\n");
HAL_NVIC_SystemReset();
/*NOTREACHED*/
return CLI_OK;
}
void configure_cli_misc(struct cli_def *cli)
{
/* reboot */
cli_command_root_node(reboot, "Reboot the STM32");
}
