mbedtls/library/lms.c
Raef Coles f5632d3efc
Remove MBEDTLS_PRIVATE usage from LMS and LMOTS
Signed-off-by: Raef Coles <raef.coles@arm.com>
2022-10-13 14:28:27 +01:00

671 lines
21 KiB
C

/*
* The LMS stateful-hash public-key signature scheme
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* The following sources were referenced in the design of this implementation
* of the LMS algorithm:
*
* [1] IETF RFC8554
* D. McGrew, M. Curcio, S.Fluhrer
* https://datatracker.ietf.org/doc/html/rfc8554
*
* [2] NIST Special Publication 800-208
* David A. Cooper et. al.
* https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-208.pdf
*/
#include "common.h"
#ifdef MBEDTLS_LMS_C
#include <string.h>
#include "lmots.h"
#include "psa/crypto.h"
#include "mbedtls/lms.h"
#include "mbedtls/error.h"
#include "mbedtls/platform_util.h"
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#include <stdio.h>
#define mbedtls_printf printf
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#define MBEDTLS_LMS_SIG_Q_LEAF_ID_OFFSET (0)
#define MBEDTLS_LMS_SIG_OTS_SIG_OFFSET (MBEDTLS_LMS_SIG_Q_LEAF_ID_OFFSET + MBEDTLS_LMOTS_Q_LEAF_ID_LEN)
#define MBEDTLS_LMS_SIG_TYPE_OFFSET (MBEDTLS_LMS_SIG_OTS_SIG_OFFSET + MBEDTLS_LMOTS_SIG_LEN)
#define MBEDTLS_LMS_SIG_PATH_OFFSET (MBEDTLS_LMS_SIG_TYPE_OFFSET + MBEDTLS_LMS_TYPE_LEN)
#define MBEDTLS_LMS_PUBLIC_KEY_TYPE_OFFSET (0)
#define MBEDTLS_LMS_PUBLIC_KEY_OTSTYPE_OFFSET (MBEDTLS_LMS_PUBLIC_KEY_TYPE_OFFSET + MBEDTLS_LMS_TYPE_LEN)
#define MBEDTLS_LMS_PUBLIC_KEY_I_KEY_ID_OFFSET (MBEDTLS_LMS_PUBLIC_KEY_OTSTYPE_OFFSET + MBEDTLS_LMOTS_TYPE_LEN)
#define MBEDTLS_LMS_PUBLIC_KEY_ROOT_NODE_OFFSET (MBEDTLS_LMS_PUBLIC_KEY_I_KEY_ID_OFFSET + MBEDTLS_LMOTS_I_KEY_ID_LEN)
#define MERKLE_TREE_NODE_AM (1u << (MBEDTLS_LMS_H_TREE_HEIGHT + 1u))
#define MERKLE_TREE_LEAF_NODE_AM (1u << MBEDTLS_LMS_H_TREE_HEIGHT)
#define MERKLE_TREE_INTERNAL_NODE_AM (1u << MBEDTLS_LMS_H_TREE_HEIGHT)
#define D_CONST_LEN (2)
static const unsigned char D_LEAF_CONSTANT_BYTES[D_CONST_LEN] = {0x82, 0x82};
static const unsigned char D_INTERNAL_CONSTANT_BYTES[D_CONST_LEN] = {0x83, 0x83};
static int create_merkle_leaf_node( const unsigned char I_key_identifier[MBEDTLS_LMOTS_I_KEY_ID_LEN],
unsigned char pub_key[MBEDTLS_LMOTS_N_HASH_LEN],
unsigned int r_node_idx,
unsigned char out[MBEDTLS_LMS_M_NODE_BYTES] )
{
psa_hash_operation_t op;
psa_status_t status;
size_t output_hash_len;
unsigned char r_node_idx_bytes[4];
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
op = psa_hash_operation_init( );
status = psa_hash_setup( &op, PSA_ALG_SHA_256 );
ret = mbedtls_lms_error_from_psa( status );
if ( ret != 0 )
goto exit;
status = psa_hash_update( &op, I_key_identifier, MBEDTLS_LMOTS_I_KEY_ID_LEN );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
unsigned_int_to_network_bytes( r_node_idx, 4, r_node_idx_bytes );
status = psa_hash_update( &op, r_node_idx_bytes, 4 );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
status = psa_hash_update( &op, D_LEAF_CONSTANT_BYTES, D_CONST_LEN );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
status = psa_hash_update( &op, pub_key, MBEDTLS_LMOTS_N_HASH_LEN );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
status = psa_hash_finish( &op, out, MBEDTLS_LMS_M_NODE_BYTES, &output_hash_len);
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
exit:
psa_hash_abort( &op );
return( ret );
}
static int create_merkle_internal_node( const unsigned char I_key_identifier[MBEDTLS_LMOTS_I_KEY_ID_LEN],
const unsigned char left_node[MBEDTLS_LMS_M_NODE_BYTES],
const unsigned char right_node[MBEDTLS_LMS_M_NODE_BYTES],
unsigned int r_node_idx,
unsigned char out[MBEDTLS_LMS_M_NODE_BYTES] )
{
psa_hash_operation_t op;
psa_status_t status;
size_t output_hash_len;
unsigned char r_node_idx_bytes[4];
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
op = psa_hash_operation_init( );
status = psa_hash_setup( &op, PSA_ALG_SHA_256 );
ret = mbedtls_lms_error_from_psa( status );
if ( ret != 0 )
goto exit;
status = psa_hash_update( &op, I_key_identifier, MBEDTLS_LMOTS_I_KEY_ID_LEN );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
unsigned_int_to_network_bytes( r_node_idx, 4, r_node_idx_bytes );
status = psa_hash_update( &op, r_node_idx_bytes, 4 );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
status = psa_hash_update( &op, D_INTERNAL_CONSTANT_BYTES, D_CONST_LEN );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
status = psa_hash_update( &op, left_node, MBEDTLS_LMOTS_N_HASH_LEN );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
status = psa_hash_update( &op, right_node, MBEDTLS_LMOTS_N_HASH_LEN );
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
ret = psa_hash_finish( &op, out, MBEDTLS_LMS_M_NODE_BYTES, &output_hash_len);
ret = mbedtls_lms_error_from_psa( status );
if( ret )
goto exit;
exit:
psa_hash_abort( &op );
return ret;
}
static int calculate_merkle_tree( mbedtls_lms_private_t *ctx,
unsigned char tree[MERKLE_TREE_NODE_AM][MBEDTLS_LMS_M_NODE_BYTES] )
{
unsigned int priv_key_idx;
unsigned int r_node_idx;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
/* First create the leaf nodes, in ascending order */
for( priv_key_idx = 0; priv_key_idx < MERKLE_TREE_INTERNAL_NODE_AM;
priv_key_idx++ )
{
r_node_idx = MERKLE_TREE_INTERNAL_NODE_AM + priv_key_idx;
ret = create_merkle_leaf_node(
ctx->params.I_key_identifier,
ctx->ots_public_keys[priv_key_idx].public_key,
r_node_idx, tree[r_node_idx] );
if( ret )
{
return( ret );
}
}
/* Then the internal nodes, in reverse order so that we can guarantee the
* parent has been created */
for( r_node_idx = MERKLE_TREE_INTERNAL_NODE_AM - 1; r_node_idx > 0;
r_node_idx-- )
{
ret = create_merkle_internal_node(
ctx->params.I_key_identifier,
tree[(r_node_idx * 2)], tree[(r_node_idx * 2 + 1)], r_node_idx, tree[r_node_idx] );
if( ret )
{
return( ret );
}
}
return( 0 );
}
static int get_merkle_path( mbedtls_lms_private_t *ctx,
unsigned int leaf_node_id,
unsigned char path[MBEDTLS_LMS_H_TREE_HEIGHT][MBEDTLS_LMS_M_NODE_BYTES] )
{
unsigned char tree[MERKLE_TREE_NODE_AM][MBEDTLS_LMS_M_NODE_BYTES];
unsigned int curr_node_id = leaf_node_id;
unsigned int adjacent_node_id;
unsigned int height;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
ret = calculate_merkle_tree( ctx, tree);
if( ret )
{
return( ret );
}
for( height = 0; height < MBEDTLS_LMS_H_TREE_HEIGHT; height++ )
{
adjacent_node_id = curr_node_id ^ 1;
memcpy( &path[height], &tree[adjacent_node_id], MBEDTLS_LMOTS_N_HASH_LEN );
curr_node_id >>=1;
}
return( 0 );
}
void mbedtls_lms_init_public( mbedtls_lms_public_t *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_lms_public_t ) ) ;
}
void mbedtls_lms_free_public( mbedtls_lms_public_t *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_lms_public_t ) );
}
int mbedtls_lms_import_public_key( mbedtls_lms_public_t *ctx,
const unsigned char *key, size_t key_size )
{
mbedtls_lms_algorithm_type_t type;
mbedtls_lmots_algorithm_type_t otstype;
if( key_size < MBEDTLS_LMS_PUBLIC_KEY_LEN )
{
return( MBEDTLS_ERR_LMS_BUFFER_TOO_SMALL );
}
type = network_bytes_to_unsigned_int( MBEDTLS_LMS_TYPE_LEN, key + MBEDTLS_LMS_PUBLIC_KEY_TYPE_OFFSET );
if( type != MBEDTLS_LMS_SHA256_M32_H10 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
ctx->params.type = type;
otstype = network_bytes_to_unsigned_int( MBEDTLS_LMOTS_TYPE_LEN,
key + MBEDTLS_LMS_PUBLIC_KEY_OTSTYPE_OFFSET );
if( otstype != MBEDTLS_LMOTS_SHA256_N32_W8 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
ctx->params.otstype = otstype;
memcpy( ctx->params.I_key_identifier,
key + MBEDTLS_LMS_PUBLIC_KEY_I_KEY_ID_OFFSET,
MBEDTLS_LMOTS_I_KEY_ID_LEN );
memcpy( ctx->T_1_pub_key, key + MBEDTLS_LMS_PUBLIC_KEY_ROOT_NODE_OFFSET,
MBEDTLS_LMOTS_N_HASH_LEN );
ctx->have_public_key = 1;
return( 0 );
}
int mbedtls_lms_verify( const mbedtls_lms_public_t *ctx,
const unsigned char *msg, size_t msg_size,
const unsigned char *sig, size_t sig_size )
{
unsigned int q_leaf_identifier;
unsigned char Kc_candidate_ots_pub_key[MBEDTLS_LMOTS_N_HASH_LEN];
unsigned char Tc_candidate_root_node[MBEDTLS_LMS_M_NODE_BYTES];
unsigned int height;
unsigned int curr_node_id;
unsigned int parent_node_id;
const unsigned char* left_node;
const unsigned char* right_node;
mbedtls_lmots_parameters_t ots_params;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( ! ctx->have_public_key )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( sig_size != MBEDTLS_LMS_SIG_LEN )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( ctx->params.type
!= MBEDTLS_LMS_SHA256_M32_H10 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( ctx->params.otstype
!= MBEDTLS_LMOTS_SHA256_N32_W8 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( network_bytes_to_unsigned_int( MBEDTLS_LMS_TYPE_LEN,
sig + MBEDTLS_LMS_SIG_TYPE_OFFSET) != MBEDTLS_LMS_SHA256_M32_H10 )
{
return( MBEDTLS_ERR_LMS_VERIFY_FAILED );
}
if( network_bytes_to_unsigned_int( MBEDTLS_LMOTS_TYPE_LEN,
sig + MBEDTLS_LMS_SIG_OTS_SIG_OFFSET + MBEDTLS_LMOTS_SIG_TYPE_OFFSET)
!= MBEDTLS_LMOTS_SHA256_N32_W8 )
{
return( MBEDTLS_ERR_LMS_VERIFY_FAILED );
}
q_leaf_identifier = network_bytes_to_unsigned_int( MBEDTLS_LMOTS_Q_LEAF_ID_LEN,
sig + MBEDTLS_LMS_SIG_Q_LEAF_ID_OFFSET );
if( q_leaf_identifier >= MERKLE_TREE_LEAF_NODE_AM )
{
return( MBEDTLS_ERR_LMS_VERIFY_FAILED );
}
memcpy(ots_params.I_key_identifier,
ctx->params.I_key_identifier,
MBEDTLS_LMOTS_I_KEY_ID_LEN);
unsigned_int_to_network_bytes( q_leaf_identifier,
MBEDTLS_LMOTS_Q_LEAF_ID_LEN,
ots_params.q_leaf_identifier );
ots_params.type = ctx->params.otstype;
ret = mbedtls_lmots_calculate_public_key_candidate( &ots_params, msg, msg_size,
sig + MBEDTLS_LMS_SIG_OTS_SIG_OFFSET,
MBEDTLS_LMOTS_SIG_LEN,
Kc_candidate_ots_pub_key,
sizeof(Kc_candidate_ots_pub_key),
NULL );
if( ret )
{
return( ret );
}
create_merkle_leaf_node(
ctx->params.I_key_identifier,
Kc_candidate_ots_pub_key, MERKLE_TREE_INTERNAL_NODE_AM + q_leaf_identifier,
Tc_candidate_root_node );
curr_node_id = MERKLE_TREE_INTERNAL_NODE_AM + q_leaf_identifier;
for( height = 0; height < MBEDTLS_LMS_H_TREE_HEIGHT; height++ )
{
parent_node_id = curr_node_id / 2;
/* Left/right node ordering matters for the hash */
if( curr_node_id & 1 )
{
left_node = ( ( const unsigned char( * )[MBEDTLS_LMS_M_NODE_BYTES] )( sig + MBEDTLS_LMS_SIG_PATH_OFFSET ) )[height];
right_node = Tc_candidate_root_node;
}
else
{
left_node = Tc_candidate_root_node;
right_node = ( ( const unsigned char( * )[MBEDTLS_LMS_M_NODE_BYTES] )( sig + MBEDTLS_LMS_SIG_PATH_OFFSET ) )[height];
}
create_merkle_internal_node(
ctx->params.I_key_identifier,
left_node, right_node, parent_node_id, Tc_candidate_root_node);
curr_node_id /= 2;
}
if( memcmp( Tc_candidate_root_node, ctx->T_1_pub_key,
MBEDTLS_LMOTS_N_HASH_LEN) )
{
return( MBEDTLS_ERR_LMS_VERIFY_FAILED );
}
return( 0 );
}
void mbedtls_lms_init_private( mbedtls_lms_private_t *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_lms_public_t ) ) ;
}
void mbedtls_lms_free_private( mbedtls_lms_private_t *ctx )
{
unsigned int idx;
if( ctx->have_private_key )
{
for( idx = 0; idx < MERKLE_TREE_LEAF_NODE_AM; idx++ )
{
mbedtls_lmots_free_private( &ctx->ots_private_keys[idx] );
mbedtls_lmots_free_public( &ctx->ots_public_keys[idx] );
}
mbedtls_free( ctx->ots_private_keys );
mbedtls_free( ctx->ots_public_keys );
}
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_lms_public_t ) );
}
int mbedtls_lms_generate_private_key( mbedtls_lms_private_t *ctx,
mbedtls_lms_algorithm_type_t type,
mbedtls_lmots_algorithm_type_t otstype,
int (*f_rng)(void *, unsigned char *, size_t),
void* p_rng, unsigned char *seed,
size_t seed_size )
{
unsigned int idx = 0;
unsigned int free_idx = 0;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( type != MBEDTLS_LMS_SHA256_M32_H10 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( otstype != MBEDTLS_LMOTS_SHA256_N32_W8 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( ctx->have_private_key )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
ctx->params.type = type;
ctx->params.otstype = otstype;
f_rng( p_rng,
ctx->params.I_key_identifier,
MBEDTLS_LMOTS_I_KEY_ID_LEN );
ctx->ots_private_keys = mbedtls_calloc( MERKLE_TREE_LEAF_NODE_AM,
sizeof( mbedtls_lmots_private_t));
if( ctx->ots_private_keys == NULL )
{
ret = MBEDTLS_ERR_LMS_ALLOC_FAILED;
goto exit;
}
ctx->ots_public_keys = mbedtls_calloc( MERKLE_TREE_LEAF_NODE_AM,
sizeof( mbedtls_lmots_public_t));
if( ctx->ots_public_keys == NULL )
{
ret = MBEDTLS_ERR_LMS_ALLOC_FAILED;
goto exit;
}
for( idx = 0; idx < MERKLE_TREE_LEAF_NODE_AM; idx++ )
{
mbedtls_lmots_init_private( &ctx->ots_private_keys[idx] );
mbedtls_lmots_init_public( &ctx->ots_public_keys[idx] );
}
for( idx = 0; idx < MERKLE_TREE_LEAF_NODE_AM; idx++ )
{
ret = mbedtls_lmots_generate_private_key( &ctx->ots_private_keys[idx],
otstype,
ctx->params.I_key_identifier,
idx, seed, seed_size );
if( ret)
goto exit;
ret = mbedtls_lmots_calculate_public_key( &ctx->ots_public_keys[idx],
&ctx->ots_private_keys[idx] );
if( ret)
goto exit;
}
ctx->q_next_usable_key = 0;
ctx->have_private_key = 1;
exit:
if( ret )
{
for ( free_idx = 0; free_idx < idx; free_idx++ ) {
mbedtls_lmots_free_private( &ctx->ots_private_keys[free_idx] );
mbedtls_lmots_free_public( &ctx->ots_public_keys[free_idx] );
}
mbedtls_free( ctx->ots_private_keys );
mbedtls_free( ctx->ots_public_keys );
return( ret );
}
return( 0 );
}
int mbedtls_lms_calculate_public_key( mbedtls_lms_public_t *ctx,
mbedtls_lms_private_t *priv_ctx )
{
unsigned char tree[MERKLE_TREE_NODE_AM][MBEDTLS_LMS_M_NODE_BYTES];
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( ! priv_ctx->MBEDTLS_PRIVATE( have_private_key ) )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( priv_ctx->params.type
!= MBEDTLS_LMS_SHA256_M32_H10 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( priv_ctx->params.otstype
!= MBEDTLS_LMOTS_SHA256_N32_W8 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
memcpy( &ctx->params, &priv_ctx->params,
sizeof(mbedtls_lmots_parameters_t) );
ret = calculate_merkle_tree( priv_ctx, tree);
if( ret )
{
return( ret );
}
/* Root node is always at position 1, due to 1-based indexing */
memcpy( ctx->T_1_pub_key, &tree[1], MBEDTLS_LMOTS_N_HASH_LEN );
ctx->have_public_key = 1;
return( 0 );
}
int mbedtls_lms_export_public_key( mbedtls_lms_public_t *ctx, unsigned char *key,
size_t key_size, size_t *key_len )
{
if( key_size < MBEDTLS_LMS_PUBLIC_KEY_LEN ) {
return( MBEDTLS_ERR_LMS_BUFFER_TOO_SMALL );
}
if( ! ctx->have_public_key )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
unsigned_int_to_network_bytes(
ctx->params.type,
MBEDTLS_LMS_TYPE_LEN, key + MBEDTLS_LMS_PUBLIC_KEY_TYPE_OFFSET );
unsigned_int_to_network_bytes(
ctx->params.otstype,
MBEDTLS_LMOTS_TYPE_LEN, key + MBEDTLS_LMS_PUBLIC_KEY_OTSTYPE_OFFSET );
memcpy( key + MBEDTLS_LMS_PUBLIC_KEY_I_KEY_ID_OFFSET,
ctx->params.I_key_identifier,
MBEDTLS_LMOTS_I_KEY_ID_LEN );
memcpy( key + MBEDTLS_LMS_PUBLIC_KEY_ROOT_NODE_OFFSET,
ctx->T_1_pub_key,
MBEDTLS_LMOTS_N_HASH_LEN );
if( key_len != NULL ) {
*key_len = MBEDTLS_LMS_PUBLIC_KEY_LEN;
}
return( 0 );
}
int mbedtls_lms_sign( mbedtls_lms_private_t *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void* p_rng, unsigned char *msg, unsigned int msg_size,
unsigned char *sig, size_t sig_size, size_t *sig_len)
{
uint32_t q_leaf_identifier;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( ! ctx->have_private_key )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( sig_size < MBEDTLS_LMS_SIG_LEN )
{
return( MBEDTLS_ERR_LMS_BUFFER_TOO_SMALL );
}
if( ctx->params.type != MBEDTLS_LMS_SHA256_M32_H10 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( ctx->params.otstype
!= MBEDTLS_LMOTS_SHA256_N32_W8 )
{
return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA );
}
if( ctx->q_next_usable_key >= MERKLE_TREE_LEAF_NODE_AM )
{
return( MBEDTLS_ERR_LMS_OUT_OF_PRIVATE_KEYS );
}
q_leaf_identifier = ctx->q_next_usable_key;
/* This new value must _always_ be written back to the disk before the
* signature is returned.
*/
ctx->q_next_usable_key += 1;
ret = mbedtls_lmots_sign( &ctx->ots_private_keys[q_leaf_identifier],
f_rng, p_rng, msg, msg_size,
sig + MBEDTLS_LMS_SIG_OTS_SIG_OFFSET,
MBEDTLS_LMS_SIG_LEN, NULL );
if( ret )
{
return( ret );
}
unsigned_int_to_network_bytes( ctx->params.type,
MBEDTLS_LMS_TYPE_LEN, sig + MBEDTLS_LMS_SIG_TYPE_OFFSET );
unsigned_int_to_network_bytes( q_leaf_identifier, MBEDTLS_LMOTS_Q_LEAF_ID_LEN,
sig + MBEDTLS_LMS_SIG_Q_LEAF_ID_OFFSET);
ret = get_merkle_path( ctx, MERKLE_TREE_INTERNAL_NODE_AM + q_leaf_identifier,
( unsigned char( * )[MBEDTLS_LMS_M_NODE_BYTES] )( sig + MBEDTLS_LMS_SIG_PATH_OFFSET ) );
if( ret )
{
return( ret );
}
if( sig_len != NULL ) {
*sig_len = MBEDTLS_LMS_SIG_LEN;
}
return( 0 );
}
#endif /* MBEDTLS_LMS_C */