Add olen parameter to ecp_ansi_write_group and ecp_ansi_write_point

Improve mbedtls_ecp_ansi_write_point
This commit is contained in:
Unknown 2018-02-06 03:26:11 -05:00
parent a2c406286a
commit dc3111e6d9
3 changed files with 35 additions and 24 deletions

View file

@ -515,13 +515,14 @@ int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, size_t *olen,
* \param grp ECP group used
* \param buf Buffer to write to
* \param size Buffer size
*
* \return Number of bytes written to \c buf,
* \param olen Number of bytes written to \c buf
* \return 0 on success
* or \c MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
* or \c MBEDTLS_ERR_OID_NOT_FOUND
*/
int mbedtls_ecp_ansi_write_group( const mbedtls_ecp_group *grp,
unsigned char *p, size_t size );
unsigned char *p, size_t size,
size_t *olen );
/**
* \brief Export a point in ANSI X9.62/RFC5480 ECPoint
@ -533,8 +534,9 @@ int mbedtls_ecp_ansi_write_group( const mbedtls_ecp_group *grp,
* \param format Point format, should be a MBEDTLS_ECP_PF_XXX macro
* \param p Buffer to write to
* \param size Buffer size
* \param olen Number of bytes written to \c buf
*
* \return Number of bytes written to \c buf,
* \return 0 on success
* or \c MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
* or \c MBEDTLS_ERR_ECP_BAD_INPUT_DATA
* or \c MBEDTLS_ERR_ASN1_BUF_TOO_SMALL
@ -542,7 +544,7 @@ int mbedtls_ecp_ansi_write_group( const mbedtls_ecp_group *grp,
int mbedtls_ecp_ansi_write_point( const mbedtls_ecp_keypair *ec,
int format,
unsigned char *p,
size_t size );
size_t size, size_t *olen );
#endif /* defined(MBEDTLS_ASN1_WRITE_C) && defined(MBEDTLS_OID_C) */
/**

View file

@ -2066,12 +2066,13 @@ cleanup:
#include "mbedtls/oid.h"
int mbedtls_ecp_ansi_write_group( const mbedtls_ecp_group *grp,
unsigned char *p,
size_t size )
size_t size, size_t *olen )
{
const char *oid;
unsigned char *q;
size_t oid_length;
int ret;
ret = mbedtls_oid_get_oid_by_ec_grp( grp->id, &oid, &oid_length );
if( ret != 0 )
return( ret );
@ -2079,36 +2080,38 @@ int mbedtls_ecp_ansi_write_group( const mbedtls_ecp_group *grp,
if( size < 2 + oid_length )
return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
q = p + 2 + oid_length;
return( mbedtls_asn1_write_oid( &q, p, oid, oid_length ) );
*olen = mbedtls_asn1_write_oid( &q, p, oid, oid_length );
return ( 0 );
}
int mbedtls_ecp_ansi_write_point( const mbedtls_ecp_keypair *ec,
int format,
unsigned char *p,
size_t size )
size_t size, size_t *olen )
{
unsigned char *q;
size_t length;
size_t tl_size = 3; /* room for the OCTET_STRING tag and length */
size_t tl_max_size = 3; /* room for the OCTET_STRING tag and length */
int ret;
if( size < tl_size )
if( size < tl_max_size )
return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
q = p + tl_size;
q = p + tl_max_size;
ret = mbedtls_ecp_point_write_binary( &ec->grp, &ec->Q,
format,
&length, q, size - 3 );
olen, q, size - tl_max_size );
if( ret < 0 )
return( ret );
ret = mbedtls_asn1_write_len( &q, p, length );
ret = mbedtls_asn1_write_len( &q, p, *olen );
if( ret < 0 )
return( ret );
ret = mbedtls_asn1_write_tag( &q, p, MBEDTLS_ASN1_OCTET_STRING );
if( ret < 0 )
return( ret );
length += tl_size - ( q - p );
*olen += tl_max_size - ( q - p );
if( q != p )
memmove( p, q, length );
return( length );
memmove( p, q, *olen );
return( 0 );
}
#endif /* defined(MBEDTLS_ASN1_WRITE_C) && defined(MBEDTLS_OID_C) */

View file

@ -420,17 +420,20 @@ void ecp_ansi_write_group( int id, char *hex )
unsigned char good[MBEDTLS_OID_EC_GRP_MAX_SIZE];
unsigned char tested[MBEDTLS_OID_EC_GRP_MAX_SIZE];
size_t good_len = unhexify( good, hex );
size_t received_len = 0;
int ret = 0;
mbedtls_ecp_group_init( &grp );
TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
/* Positive test */
ret = mbedtls_ecp_ansi_write_group( &grp, tested, sizeof( tested ) );
TEST_ASSERT( ret >= 0 && good_len == (unsigned) ret );
ret = mbedtls_ecp_ansi_write_group( &grp, tested, sizeof( tested ),
&received_len );
TEST_ASSERT( ret == 0 && good_len == (unsigned) received_len );
TEST_ASSERT( memcmp( good, tested, good_len ) == 0 );
/* Buffer too small */
TEST_ASSERT( mbedtls_ecp_ansi_write_group( &grp, tested, good_len - 1 ) ==
TEST_ASSERT( mbedtls_ecp_ansi_write_group( &grp, tested, good_len - 1,
&received_len ) ==
MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
exit:
@ -444,20 +447,23 @@ void ecp_ansi_write_point( char *key_file, int format, char *good_hex )
unsigned char good_buf[1000];
unsigned char tested_buf[1000];
size_t good_len = unhexify( good_buf, good_hex );
size_t received_len = 0;
mbedtls_pk_context pk;
int ret = 0;
int ret = -1;
mbedtls_pk_init( &pk );
TEST_ASSERT( mbedtls_pk_parse_public_keyfile( &pk, key_file ) == 0 );
/* Positive test */
ret = mbedtls_ecp_ansi_write_point( mbedtls_pk_ec( pk ), format,
tested_buf, sizeof( tested_buf ) );
TEST_ASSERT( ret >= 0 && good_len == (unsigned) ret );
tested_buf, sizeof( tested_buf ),
&received_len );
TEST_ASSERT( ret == 0 && good_len == (unsigned) received_len );
TEST_ASSERT( memcmp( good_buf, tested_buf, good_len ) == 0 );
/* Buffer too small */
TEST_ASSERT( mbedtls_ecp_ansi_write_point( mbedtls_pk_ec( pk ), format,
tested_buf, good_len - 1 ) ==
tested_buf, good_len - 1,
&received_len ) ==
MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
exit: