diff options
Diffstat (limited to 'thirdparty/mbedtls/library/ecdh.c')
| -rw-r--r-- | thirdparty/mbedtls/library/ecdh.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/ecdh.c b/thirdparty/mbedtls/library/ecdh.c new file mode 100644 index 0000000000..61380b6936 --- /dev/null +++ b/thirdparty/mbedtls/library/ecdh.c @@ -0,0 +1,268 @@ +/* + * Elliptic curve Diffie-Hellman + * + * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved + * 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. + * + * This file is part of mbed TLS (https://tls.mbed.org) + */ + +/* + * References: + * + * SEC1 http://www.secg.org/index.php?action=secg,docs_secg + * RFC 4492 + */ + +#if !defined(MBEDTLS_CONFIG_FILE) +#include "mbedtls/config.h" +#else +#include MBEDTLS_CONFIG_FILE +#endif + +#if defined(MBEDTLS_ECDH_C) + +#include "mbedtls/ecdh.h" + +#include <string.h> + +#if !defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT) +/* + * Generate public key: simple wrapper around mbedtls_ecp_gen_keypair + */ +int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) +{ + return mbedtls_ecp_gen_keypair( grp, d, Q, f_rng, p_rng ); +} +#endif /* MBEDTLS_ECDH_GEN_PUBLIC_ALT */ + +#if !defined(MBEDTLS_ECDH_COMPUTE_SHARED_ALT) +/* + * Compute shared secret (SEC1 3.3.1) + */ +int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z, + const mbedtls_ecp_point *Q, const mbedtls_mpi *d, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) +{ + int ret; + mbedtls_ecp_point P; + + mbedtls_ecp_point_init( &P ); + + /* + * Make sure Q is a valid pubkey before using it + */ + MBEDTLS_MPI_CHK( mbedtls_ecp_check_pubkey( grp, Q ) ); + + MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, &P, d, Q, f_rng, p_rng ) ); + + if( mbedtls_ecp_is_zero( &P ) ) + { + ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + goto cleanup; + } + + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( z, &P.X ) ); + +cleanup: + mbedtls_ecp_point_free( &P ); + + return( ret ); +} +#endif /* MBEDTLS_ECDH_COMPUTE_SHARED_ALT */ + +/* + * Initialize context + */ +void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx ) +{ + memset( ctx, 0, sizeof( mbedtls_ecdh_context ) ); +} + +/* + * Free context + */ +void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx ) +{ + if( ctx == NULL ) + return; + + mbedtls_ecp_group_free( &ctx->grp ); + mbedtls_ecp_point_free( &ctx->Q ); + mbedtls_ecp_point_free( &ctx->Qp ); + mbedtls_ecp_point_free( &ctx->Vi ); + mbedtls_ecp_point_free( &ctx->Vf ); + mbedtls_mpi_free( &ctx->d ); + mbedtls_mpi_free( &ctx->z ); + mbedtls_mpi_free( &ctx->_d ); +} + +/* + * Setup and write the ServerKeyExhange parameters (RFC 4492) + * struct { + * ECParameters curve_params; + * ECPoint public; + * } ServerECDHParams; + */ +int mbedtls_ecdh_make_params( mbedtls_ecdh_context *ctx, size_t *olen, + unsigned char *buf, size_t blen, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) +{ + int ret; + size_t grp_len, pt_len; + + if( ctx == NULL || ctx->grp.pbits == 0 ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + + if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) ) + != 0 ) + return( ret ); + + if( ( ret = mbedtls_ecp_tls_write_group( &ctx->grp, &grp_len, buf, blen ) ) + != 0 ) + return( ret ); + + buf += grp_len; + blen -= grp_len; + + if( ( ret = mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format, + &pt_len, buf, blen ) ) != 0 ) + return( ret ); + + *olen = grp_len + pt_len; + return( 0 ); +} + +/* + * Read the ServerKeyExhange parameters (RFC 4492) + * struct { + * ECParameters curve_params; + * ECPoint public; + * } ServerECDHParams; + */ +int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx, + const unsigned char **buf, const unsigned char *end ) +{ + int ret; + + if( ( ret = mbedtls_ecp_tls_read_group( &ctx->grp, buf, end - *buf ) ) != 0 ) + return( ret ); + + if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf, end - *buf ) ) + != 0 ) + return( ret ); + + return( 0 ); +} + +/* + * Get parameters from a keypair + */ +int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypair *key, + mbedtls_ecdh_side side ) +{ + int ret; + + if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 ) + return( ret ); + + /* If it's not our key, just import the public part as Qp */ + if( side == MBEDTLS_ECDH_THEIRS ) + return( mbedtls_ecp_copy( &ctx->Qp, &key->Q ) ); + + /* Our key: import public (as Q) and private parts */ + if( side != MBEDTLS_ECDH_OURS ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + + if( ( ret = mbedtls_ecp_copy( &ctx->Q, &key->Q ) ) != 0 || + ( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 ) + return( ret ); + + return( 0 ); +} + +/* + * Setup and export the client public value + */ +int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen, + unsigned char *buf, size_t blen, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) +{ + int ret; + + if( ctx == NULL || ctx->grp.pbits == 0 ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + + if( ( ret = mbedtls_ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) ) + != 0 ) + return( ret ); + + return mbedtls_ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format, + olen, buf, blen ); +} + +/* + * Parse and import the client's public value + */ +int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx, + const unsigned char *buf, size_t blen ) +{ + int ret; + const unsigned char *p = buf; + + if( ctx == NULL ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + + if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, &p, blen ) ) != 0 ) + return( ret ); + + if( (size_t)( p - buf ) != blen ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + + return( 0 ); +} + +/* + * Derive and export the shared secret + */ +int mbedtls_ecdh_calc_secret( mbedtls_ecdh_context *ctx, size_t *olen, + unsigned char *buf, size_t blen, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) +{ + int ret; + + if( ctx == NULL ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + + if( ( ret = mbedtls_ecdh_compute_shared( &ctx->grp, &ctx->z, &ctx->Qp, &ctx->d, + f_rng, p_rng ) ) != 0 ) + { + return( ret ); + } + + if( mbedtls_mpi_size( &ctx->z ) > blen ) + return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); + + *olen = ctx->grp.pbits / 8 + ( ( ctx->grp.pbits % 8 ) != 0 ); + return mbedtls_mpi_write_binary( &ctx->z, buf, *olen ); +} + +#endif /* MBEDTLS_ECDH_C */ |