| /* |
| * 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" |
| |
| #if defined(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" |
| |
| #include "mbedtls/platform.h" |
| |
| #define SIG_Q_LEAF_ID_OFFSET (0) |
| #define SIG_OTS_SIG_OFFSET (SIG_Q_LEAF_ID_OFFSET + \ |
| MBEDTLS_LMOTS_Q_LEAF_ID_LEN) |
| #define SIG_TYPE_OFFSET(otstype) (SIG_OTS_SIG_OFFSET + \ |
| MBEDTLS_LMOTS_SIG_LEN(otstype)) |
| #define SIG_PATH_OFFSET(otstype) (SIG_TYPE_OFFSET(otstype) + \ |
| MBEDTLS_LMS_TYPE_LEN) |
| |
| #define PUBLIC_KEY_TYPE_OFFSET (0) |
| #define PUBLIC_KEY_OTSTYPE_OFFSET (PUBLIC_KEY_TYPE_OFFSET + \ |
| MBEDTLS_LMS_TYPE_LEN) |
| #define PUBLIC_KEY_I_KEY_ID_OFFSET (PUBLIC_KEY_OTSTYPE_OFFSET + \ |
| MBEDTLS_LMOTS_TYPE_LEN) |
| #define PUBLIC_KEY_ROOT_NODE_OFFSET (PUBLIC_KEY_I_KEY_ID_OFFSET + \ |
| MBEDTLS_LMOTS_I_KEY_ID_LEN) |
| |
| |
| /* Currently only support H=10 */ |
| #define H_TREE_HEIGHT_MAX 10 |
| #define MERKLE_TREE_NODE_AM_MAX (1u << (H_TREE_HEIGHT_MAX + 1u)) |
| #define MERKLE_TREE_NODE_AM(type) (1u << (MBEDTLS_LMS_H_TREE_HEIGHT(type) + 1u)) |
| #define MERKLE_TREE_LEAF_NODE_AM(type) (1u << MBEDTLS_LMS_H_TREE_HEIGHT(type)) |
| #define MERKLE_TREE_INTERNAL_NODE_AM(type) (1u << MBEDTLS_LMS_H_TREE_HEIGHT(type)) |
| |
| #define D_CONST_LEN (2) |
| static const unsigned char D_LEAF_CONSTANT_BYTES[D_CONST_LEN] = {0x82, 0x82}; |
| static const unsigned char D_INTR_CONSTANT_BYTES[D_CONST_LEN] = {0x83, 0x83}; |
| |
| |
| /* Calculate the value of a leaf node of the Merkle tree (which is a hash of a |
| * public key and some other parameters like the leaf index). This function |
| * implements RFC8554 section 5.3, in the case where r >= 2^h. |
| * |
| * params The LMS parameter set, the underlying LMOTS |
| * parameter set, and I value which describe the key |
| * being used. |
| * |
| * pub_key The public key of the private whose index |
| * corresponds to the index of this leaf node. This |
| * is a hash output. |
| * |
| * r_node_idx The index of this node in the Merkle tree. Note |
| * that the root node of the Merkle tree is |
| * 1-indexed. |
| * |
| * out The output node value, which is a hash output. |
| */ |
| static int create_merkle_leaf_value( const mbedtls_lms_parameters_t *params, |
| unsigned char *pub_key, |
| unsigned int r_node_idx, |
| unsigned char *out ) |
| { |
| psa_hash_operation_t op; |
| psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; |
| size_t output_hash_len; |
| unsigned char r_node_idx_bytes[4]; |
| |
| op = psa_hash_operation_init( ); |
| status = psa_hash_setup( &op, PSA_ALG_SHA_256 ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_update( &op, params->I_key_identifier, |
| MBEDTLS_LMOTS_I_KEY_ID_LEN ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| mbedtls_lms_unsigned_int_to_network_bytes( r_node_idx, 4, r_node_idx_bytes ); |
| status = psa_hash_update( &op, r_node_idx_bytes, 4 ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_update( &op, D_LEAF_CONSTANT_BYTES, D_CONST_LEN ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_update( &op, pub_key, |
| MBEDTLS_LMOTS_N_HASH_LEN(params->otstype) ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_finish( &op, out, MBEDTLS_LMS_M_NODE_BYTES(params->type), |
| &output_hash_len ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| exit: |
| psa_hash_abort( &op ); |
| |
| return ( mbedtls_lms_error_from_psa( status ) ); |
| } |
| |
| /* Calculate the value of an internal node of the Merkle tree (which is a hash |
| * of a public key and some other parameters like the node index). This function |
| * implements RFC8554 section 5.3, in the case where r < 2^h. |
| * |
| * params The LMS parameter set, the underlying LMOTS |
| * parameter set, and I value which describe the key |
| * being used. |
| * |
| * left_node The value of the child of this node which is on |
| * the left-hand side. As with all nodes on the |
| * Merkle tree, this is a hash output. |
| * |
| * right_node The value of the child of this node which is on |
| * the right-hand side. As with all nodes on the |
| * Merkle tree, this is a hash output. |
| * |
| * r_node_idx The index of this node in the Merkle tree. Note |
| * that the root node of the Merkle tree is |
| * 1-indexed. |
| * |
| * out The output node value, which is a hash output. |
| */ |
| static int create_merkle_internal_value( const mbedtls_lms_parameters_t *params, |
| const unsigned char *left_node, |
| const unsigned char *right_node, |
| unsigned int r_node_idx, |
| unsigned char *out ) |
| { |
| psa_hash_operation_t op; |
| psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; |
| size_t output_hash_len; |
| unsigned char r_node_idx_bytes[4]; |
| |
| op = psa_hash_operation_init( ); |
| status = psa_hash_setup( &op, PSA_ALG_SHA_256 ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_update( &op, params->I_key_identifier, |
| MBEDTLS_LMOTS_I_KEY_ID_LEN ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| mbedtls_lms_unsigned_int_to_network_bytes( r_node_idx, 4, r_node_idx_bytes ); |
| status = psa_hash_update( &op, r_node_idx_bytes, 4 ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_update( &op, D_INTR_CONSTANT_BYTES, D_CONST_LEN ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_update( &op, left_node, |
| MBEDTLS_LMS_M_NODE_BYTES(params->type) ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_update( &op, right_node, |
| MBEDTLS_LMS_M_NODE_BYTES(params->type) ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| status = psa_hash_finish( &op, out, MBEDTLS_LMS_M_NODE_BYTES(params->type), |
| &output_hash_len ); |
| if( status != PSA_SUCCESS ) |
| goto exit; |
| |
| exit: |
| psa_hash_abort( &op ); |
| |
| return( mbedtls_lms_error_from_psa( status ) ); |
| } |
| |
| void mbedtls_lms_public_init( mbedtls_lms_public_t *ctx ) |
| { |
| memset( ctx, 0, sizeof( *ctx ) ) ; |
| } |
| |
| void mbedtls_lms_public_free( mbedtls_lms_public_t *ctx ) |
| { |
| mbedtls_platform_zeroize( ctx, sizeof( *ctx ) ); |
| } |
| |
| 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; |
| |
| type = mbedtls_lms_network_bytes_to_unsigned_int( MBEDTLS_LMS_TYPE_LEN, |
| key + PUBLIC_KEY_TYPE_OFFSET ); |
| if( type != MBEDTLS_LMS_SHA256_M32_H10 ) |
| { |
| return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA ); |
| } |
| ctx->params.type = type; |
| |
| if( key_size != MBEDTLS_LMS_PUBLIC_KEY_LEN(ctx->params.type) ) |
| { |
| return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA ); |
| } |
| |
| otstype = mbedtls_lms_network_bytes_to_unsigned_int( MBEDTLS_LMOTS_TYPE_LEN, |
| key + 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 + PUBLIC_KEY_I_KEY_ID_OFFSET, |
| MBEDTLS_LMOTS_I_KEY_ID_LEN ); |
| memcpy( ctx->T_1_pub_key, key + PUBLIC_KEY_ROOT_NODE_OFFSET, |
| MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type) ); |
| |
| ctx->have_public_key = 1; |
| |
| return( 0 ); |
| } |
| |
| int mbedtls_lms_export_public_key( const mbedtls_lms_public_t *ctx, |
| unsigned char *key, |
| size_t key_size, size_t *key_len ) |
| { |
| if( key_size < MBEDTLS_LMS_PUBLIC_KEY_LEN(ctx->params.type) ) |
| { |
| return( MBEDTLS_ERR_LMS_BUFFER_TOO_SMALL ); |
| } |
| |
| if( ! ctx->have_public_key ) |
| { |
| return( MBEDTLS_ERR_LMS_BAD_INPUT_DATA ); |
| } |
| |
| mbedtls_lms_unsigned_int_to_network_bytes( |
| ctx->params.type, |
| MBEDTLS_LMS_TYPE_LEN, key + PUBLIC_KEY_TYPE_OFFSET ); |
| mbedtls_lms_unsigned_int_to_network_bytes( ctx->params.otstype, |
| MBEDTLS_LMOTS_TYPE_LEN, |
| key + PUBLIC_KEY_OTSTYPE_OFFSET ); |
| memcpy( key + PUBLIC_KEY_I_KEY_ID_OFFSET, |
| ctx->params.I_key_identifier, |
| MBEDTLS_LMOTS_I_KEY_ID_LEN ); |
| memcpy( key +PUBLIC_KEY_ROOT_NODE_OFFSET, |
| ctx->T_1_pub_key, |
| MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type) ); |
| |
| if( key_len != NULL ) |
| { |
| *key_len = MBEDTLS_LMS_PUBLIC_KEY_LEN(ctx->params.type); |
| } |
| |
| 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_MAX]; |
| unsigned char Tc_candidate_root_node[MBEDTLS_LMS_M_NODE_BYTES_MAX]; |
| 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( 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( sig_size != MBEDTLS_LMS_SIG_LEN(ctx->params.type, ctx->params.otstype) ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| if( sig_size < SIG_OTS_SIG_OFFSET + MBEDTLS_LMOTS_TYPE_LEN ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| if( mbedtls_lms_network_bytes_to_unsigned_int( MBEDTLS_LMOTS_TYPE_LEN, |
| sig + SIG_OTS_SIG_OFFSET + MBEDTLS_LMOTS_SIG_TYPE_OFFSET ) |
| != MBEDTLS_LMOTS_SHA256_N32_W8 ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| if( sig_size < SIG_TYPE_OFFSET(ctx->params.otstype) + MBEDTLS_LMS_TYPE_LEN ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| if( mbedtls_lms_network_bytes_to_unsigned_int( MBEDTLS_LMS_TYPE_LEN, |
| sig + SIG_TYPE_OFFSET(ctx->params.otstype)) |
| != MBEDTLS_LMS_SHA256_M32_H10 ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| |
| q_leaf_identifier = mbedtls_lms_network_bytes_to_unsigned_int( |
| MBEDTLS_LMOTS_Q_LEAF_ID_LEN, sig + SIG_Q_LEAF_ID_OFFSET ); |
| |
| if( q_leaf_identifier >= MERKLE_TREE_LEAF_NODE_AM(ctx->params.type) ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| memcpy( ots_params.I_key_identifier, |
| ctx->params.I_key_identifier, |
| MBEDTLS_LMOTS_I_KEY_ID_LEN ); |
| mbedtls_lms_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 + SIG_OTS_SIG_OFFSET, |
| MBEDTLS_LMOTS_SIG_LEN(ctx->params.otstype), Kc_candidate_ots_pub_key, |
| sizeof( Kc_candidate_ots_pub_key ), NULL ); |
| if( ret != 0 ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| create_merkle_leaf_value( |
| &ctx->params, |
| Kc_candidate_ots_pub_key, |
| MERKLE_TREE_INTERNAL_NODE_AM(ctx->params.type) + q_leaf_identifier, |
| Tc_candidate_root_node ); |
| |
| curr_node_id = MERKLE_TREE_INTERNAL_NODE_AM(ctx->params.type) + |
| q_leaf_identifier; |
| |
| for( height = 0; height < MBEDTLS_LMS_H_TREE_HEIGHT(ctx->params.type); |
| height++ ) |
| { |
| parent_node_id = curr_node_id / 2; |
| |
| /* Left/right node ordering matters for the hash */ |
| if( curr_node_id & 1 ) |
| { |
| left_node = sig + SIG_PATH_OFFSET(ctx->params.otstype) + |
| height * MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type); |
| right_node = Tc_candidate_root_node; |
| } |
| else |
| { |
| left_node = Tc_candidate_root_node; |
| right_node = sig + SIG_PATH_OFFSET(ctx->params.otstype) + |
| height * MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type); |
| } |
| |
| create_merkle_internal_value( &ctx->params, 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_LMS_M_NODE_BYTES(ctx->params.type)) ) |
| { |
| return( MBEDTLS_ERR_LMS_VERIFY_FAILED ); |
| } |
| |
| return( 0 ); |
| } |
| |
| #if defined(MBEDTLS_LMS_PRIVATE) |
| |
| /* Calculate a full Merkle tree based on a private key. This function |
| * implements RFC8554 section 5.3, and is used to generate a public key (as the |
| * public key is the root node of the Merkle tree). |
| * |
| * ctx The LMS private context, containing a parameter |
| * set and private key material consisting of both |
| * public and private OTS. |
| * |
| * tree The output tree, which is 2^(H + 1) hash outputs. |
| * In the case of H=10 we have 2048 tree nodes (of |
| * which 1024 of them are leaf nodes). Note that |
| * because the Merkle tree root is 1-indexed, the 0 |
| * index tree node is never used. |
| */ |
| static int calculate_merkle_tree( const mbedtls_lms_private_t *ctx, |
| unsigned char *tree ) |
| { |
| 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(ctx->params.type); |
| priv_key_idx++ ) |
| { |
| r_node_idx = MERKLE_TREE_INTERNAL_NODE_AM(ctx->params.type) + priv_key_idx; |
| |
| ret = create_merkle_leaf_value( &ctx->params, |
| ctx->ots_public_keys[priv_key_idx].public_key, r_node_idx, |
| &tree[r_node_idx * MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type)] ); |
| if( ret != 0 ) |
| { |
| 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(ctx->params.type) - 1; |
| r_node_idx > 0; |
| r_node_idx-- ) |
| { |
| ret = create_merkle_internal_value( &ctx->params, |
| &tree[( r_node_idx * 2 ) * MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type)], |
| &tree[( r_node_idx * 2 + 1 ) * MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type)], |
| r_node_idx, |
| &tree[r_node_idx * MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type)] ); |
| if( ret != 0 ) |
| { |
| return( ret ); |
| } |
| } |
| |
| return( 0 ); |
| } |
| |
| /* Calculate a path from a leaf node of the Merkle tree to the root of the tree, |
| * and return the full path. This function implements RFC8554 section 5.4.1, as |
| * the Merkle path is the main component of an LMS signature. |
| * |
| * ctx The LMS private context, containing a parameter |
| * set and private key material consisting of both |
| * public and private OTS. |
| * |
| * leaf_node_id Which leaf node to calculate the path from. |
| * |
| * path The output path, which is H hash outputs. |
| */ |
| static int get_merkle_path( mbedtls_lms_private_t *ctx, |
| unsigned int leaf_node_id, |
| unsigned char *path ) |
| { |
| unsigned char tree[MERKLE_TREE_NODE_AM_MAX][MBEDTLS_LMS_M_NODE_BYTES_MAX]; |
| 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, ( unsigned char * )tree ); |
| if( ret != 0 ) |
| { |
| goto exit; |
| } |
| |
| for( height = 0; height < MBEDTLS_LMS_H_TREE_HEIGHT(ctx->params.type); |
| height++ ) |
| { |
| adjacent_node_id = curr_node_id ^ 1; |
| |
| memcpy( &path[height * MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type)], |
| &tree[adjacent_node_id], |
| MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type) ); |
| |
| curr_node_id >>=1; |
| } |
| |
| ret = 0; |
| |
| exit: |
| mbedtls_platform_zeroize( tree, sizeof( tree ) ); |
| |
| return( ret ); |
| } |
| |
| void mbedtls_lms_private_init( mbedtls_lms_private_t *ctx ) |
| { |
| memset( ctx, 0, sizeof( *ctx ) ) ; |
| } |
| |
| void mbedtls_lms_private_free( mbedtls_lms_private_t *ctx ) |
| { |
| unsigned int idx; |
| |
| if( ctx->have_private_key ) |
| { |
| if( ctx->ots_private_keys != NULL ) |
| { |
| for( idx = 0; idx < MERKLE_TREE_LEAF_NODE_AM(ctx->params.type); idx++ ) |
| { |
| mbedtls_lmots_private_free( &ctx->ots_private_keys[idx] ); |
| } |
| } |
| |
| if( ctx->ots_public_keys != NULL ) |
| { |
| for( idx = 0; idx < MERKLE_TREE_LEAF_NODE_AM(ctx->params.type); idx++ ) |
| { |
| mbedtls_lmots_public_free( &ctx->ots_public_keys[idx] ); |
| } |
| } |
| |
| mbedtls_free( ctx->ots_private_keys ); |
| mbedtls_free( ctx->ots_public_keys ); |
| } |
| |
| mbedtls_platform_zeroize( ctx, sizeof( *ctx ) ); |
| } |
| |
| |
| 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, const unsigned char *seed, |
| size_t seed_size ) |
| { |
| unsigned int 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; |
| ctx->have_private_key = 1; |
| |
| ret = f_rng( p_rng, |
| ctx->params.I_key_identifier, |
| MBEDTLS_LMOTS_I_KEY_ID_LEN ); |
| if( ret != 0 ) |
| { |
| goto exit; |
| } |
| |
| /* Requires a cast to size_t to avoid an implicit cast warning on certain |
| * platforms (particularly Windows) */ |
| ctx->ots_private_keys = mbedtls_calloc( ( size_t )MERKLE_TREE_LEAF_NODE_AM(ctx->params.type), |
| sizeof( *ctx->ots_private_keys ) ); |
| if( ctx->ots_private_keys == NULL ) |
| { |
| ret = MBEDTLS_ERR_LMS_ALLOC_FAILED; |
| goto exit; |
| } |
| |
| /* Requires a cast to size_t to avoid an implicit cast warning on certain |
| * platforms (particularly Windows) */ |
| ctx->ots_public_keys = mbedtls_calloc( ( size_t )MERKLE_TREE_LEAF_NODE_AM(ctx->params.type), |
| sizeof( *ctx->ots_public_keys ) ); |
| if( ctx->ots_public_keys == NULL ) |
| { |
| ret = MBEDTLS_ERR_LMS_ALLOC_FAILED; |
| goto exit; |
| } |
| |
| for( idx = 0; idx < MERKLE_TREE_LEAF_NODE_AM(ctx->params.type); idx++ ) |
| { |
| mbedtls_lmots_private_init( &ctx->ots_private_keys[idx] ); |
| mbedtls_lmots_public_init( &ctx->ots_public_keys[idx] ); |
| } |
| |
| |
| for( idx = 0; idx < MERKLE_TREE_LEAF_NODE_AM(ctx->params.type); idx++ ) |
| { |
| ret = mbedtls_lmots_generate_private_key( &ctx->ots_private_keys[idx], |
| otstype, |
| ctx->params.I_key_identifier, |
| idx, seed, seed_size ); |
| if( ret != 0 ) |
| goto exit; |
| |
| ret = mbedtls_lmots_calculate_public_key( &ctx->ots_public_keys[idx], |
| &ctx->ots_private_keys[idx] ); |
| if( ret != 0 ) |
| goto exit; |
| } |
| |
| ctx->q_next_usable_key = 0; |
| |
| exit: |
| if( ret != 0 ) |
| { |
| mbedtls_lms_private_free(ctx); |
| } |
| |
| return( ret ); |
| } |
| |
| int mbedtls_lms_calculate_public_key( mbedtls_lms_public_t *ctx, |
| const mbedtls_lms_private_t *priv_ctx ) |
| { |
| unsigned char tree[MERKLE_TREE_NODE_AM_MAX][MBEDTLS_LMS_M_NODE_BYTES_MAX]; |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| if( ! priv_ctx->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, ( unsigned char * )tree ); |
| if( ret != 0 ) |
| { |
| goto exit; |
| } |
| |
| /* Root node is always at position 1, due to 1-based indexing */ |
| memcpy( ctx->T_1_pub_key, &tree[1], |
| MBEDTLS_LMS_M_NODE_BYTES(ctx->params.type) ); |
| |
| ctx->have_public_key = 1; |
| |
| ret = 0; |
| |
| exit: |
| mbedtls_platform_zeroize( tree, sizeof( tree ) ); |
| |
| return( ret ); |
| } |
| |
| |
| int mbedtls_lms_sign( mbedtls_lms_private_t *ctx, |
| int (*f_rng)(void *, unsigned char *, size_t), |
| void* p_rng, const 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(ctx->params.type, ctx->params.otstype) ) |
| { |
| 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(ctx->params.type) ) |
| { |
| 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; |
| |
| if ( MBEDTLS_LMS_SIG_LEN(ctx->params.type, ctx->params.otstype) |
| < SIG_OTS_SIG_OFFSET ) |
| { |
| return ( MBEDTLS_ERR_LMS_BAD_INPUT_DATA ); |
| } |
| |
| ret = mbedtls_lmots_sign( &ctx->ots_private_keys[q_leaf_identifier], |
| f_rng, p_rng, msg, msg_size, |
| sig + SIG_OTS_SIG_OFFSET, |
| MBEDTLS_LMS_SIG_LEN(ctx->params.type, ctx->params.otstype) - SIG_OTS_SIG_OFFSET, |
| NULL ); |
| if( ret != 0 ) |
| { |
| return( ret ); |
| } |
| |
| mbedtls_lms_unsigned_int_to_network_bytes( ctx->params.type, |
| MBEDTLS_LMS_TYPE_LEN, |
| sig + SIG_TYPE_OFFSET(ctx->params.otstype) ); |
| mbedtls_lms_unsigned_int_to_network_bytes( q_leaf_identifier, |
| MBEDTLS_LMOTS_Q_LEAF_ID_LEN, |
| sig + SIG_Q_LEAF_ID_OFFSET ); |
| |
| ret = get_merkle_path( ctx, |
| MERKLE_TREE_INTERNAL_NODE_AM(ctx->params.type) + q_leaf_identifier, |
| sig + SIG_PATH_OFFSET(ctx->params.otstype) ); |
| if( ret != 0 ) |
| { |
| return( ret ); |
| } |
| |
| if( sig_len != NULL ) |
| { |
| *sig_len = MBEDTLS_LMS_SIG_LEN(ctx->params.type, ctx->params.otstype); |
| } |
| |
| |
| return( 0 ); |
| } |
| |
| #endif /* defined(MBEDTLS_LMS_PRIVATE) */ |
| #endif /* defined(MBEDTLS_LMS_C) */ |