cuberite/polarssl
1
0
Fork 0
mirror of https://github.com/cuberite/polarssl.git synced 2025-11-03 20:22:59 -05:00
Code Issues Packages Projects Releases Wiki Activity

ECDH: Add mbedtls_ecdh_setup()

Browse Source 
In the future we want to support alternative ECDH implementations. We
can't make assumptions about the structure of the context they might
use, and therefore shouldn't access the members of
`mbedtls_ecdh_context`.

Currently the lifecycle of the context can't be done without direct
manipulation. This commit adds `mbedtls_ecdh_setup()` to complete
covering the context lifecycle with functions.
This commit is contained in:
Janos Follath 2018-10-30 11:53:25 +00:00
parent 89ac8c9266
commit f61e486179
2 changed files with 49 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
include/mbedtls/ecdh.h
View File

@ -134,6 +134,24 @@ int mbedtls_ecdh_compute_shared( mbedtls_ecp_group *grp, mbedtls_mpi *z,
*/ */
void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx ); void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx );
/**
* \brief This function sets up the ECDH context with the information
* given.
*
* This function should be called after mbedtls_ecdh_init() but
* before mbedtls_ecdh_make_params(). There is no need to call
* this function before mbedtls_ecdh_read_params().
*
* This is the first function used by a TLS server for ECDHE
* ciphersuites.
*
* \param ctx The ECDH context to set up.
* \param grp_id The group id of the group to set up the context for.
*
* \return \c 0 on success.
*/
int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id );
/** /**
* \brief This function frees a context. * \brief This function frees a context.
* *
@ -145,8 +163,8 @@ void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx );
* \brief This function generates a public key and a TLS * \brief This function generates a public key and a TLS
* ServerKeyExchange payload. * ServerKeyExchange payload.
* *
* This is the first function used by a TLS server for ECDHE * This is the second function used by a TLS server for ECDHE
* ciphersuites. * ciphersuites. (It is called after mbedtls_ecdh_setup().)
* *
* \note This function assumes that the ECP group (grp) of the * \note This function assumes that the ECP group (grp) of the
* \p ctx context has already been properly set, * \p ctx context has already been properly set,
@ -242,8 +260,9 @@ int mbedtls_ecdh_make_public( mbedtls_ecdh_context *ctx, size_t *olen,
* \brief This function parses and processes a TLS ClientKeyExchange * \brief This function parses and processes a TLS ClientKeyExchange
* payload. * payload.
* *
* This is the second function used by a TLS server for ECDH(E) * This is the third function used by a TLS server for ECDH(E)
* ciphersuites. * ciphersuites. (It is called after mbedtls_ecdh_setup() and
* mbedtls_ecdh_make_params().)
* *
* \see ecp.h * \see ecp.h
* *

30
library/ecdh.c
View File

@ -145,6 +145,23 @@ void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
#endif #endif
} }
/*
* Setup context
*/
int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )
{
int ret;
ret = mbedtls_ecp_group_load( &ctx->grp, grp_id );
if( ret != 0 )
{
mbedtls_ecdh_free( ctx );
return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
}
return( 0 );
}
/* /*
* Free context * Free context
*/ */
@ -240,12 +257,17 @@ int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
const unsigned char **buf, const unsigned char *end ) const unsigned char **buf, const unsigned char *end )
{ {
int ret; int ret;
mbedtls_ecp_group_id grp_id;
if( ( ret = mbedtls_ecp_tls_read_group( &ctx->grp, buf, end - *buf ) ) != 0 ) if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, end - *buf ) )
!= 0 )
return( ret ); return( ret );
if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf, end - *buf ) ) if( ( ret = mbedtls_ecdh_setup( ctx, grp_id ) ) != 0 )
!= 0 ) return( ret );
if( ( ret = mbedtls_ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf,
end - *buf ) ) != 0 )
return( ret ); return( ret );
return( 0 ); return( 0 );
@ -259,7 +281,7 @@ int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypai
{ {
int ret; int ret;
if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 ) if( ( ret = mbedtls_ecdh_setup( ctx, key->grp.id ) ) != 0 )
return( ret ); return( ret );
/* If it's not our key, just import the public part as Qp */ /* If it's not our key, just import the public part as Qp */