713 lines
20 KiB
C
713 lines
20 KiB
C
/*
|
|
* Diffie-Hellman-Merkle key exchange
|
|
*
|
|
* 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 Diffie-Hellman-Merkle algorithm:
|
|
*
|
|
* [1] Handbook of Applied Cryptography - 1997, Chapter 12
|
|
* Menezes, van Oorschot and Vanstone
|
|
*
|
|
*/
|
|
|
|
#include "common.h"
|
|
|
|
#if defined(MBEDTLS_DHM_C)
|
|
|
|
#include "mbedtls/dhm.h"
|
|
#include "mbedtls/platform_util.h"
|
|
#include "mbedtls/error.h"
|
|
|
|
#include <string.h>
|
|
|
|
#if defined(MBEDTLS_PEM_PARSE_C)
|
|
#include "mbedtls/pem.h"
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_ASN1_PARSE_C)
|
|
#include "mbedtls/asn1.h"
|
|
#endif
|
|
|
|
#include "mbedtls/platform.h"
|
|
|
|
#if !defined(MBEDTLS_DHM_ALT)
|
|
|
|
/*
|
|
* helper to validate the mbedtls_mpi size and import it
|
|
*/
|
|
static int dhm_read_bignum( mbedtls_mpi *X,
|
|
unsigned char **p,
|
|
const unsigned char *end )
|
|
{
|
|
int ret, n;
|
|
|
|
if( end - *p < 2 )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
n = ( (*p)[0] << 8 ) | (*p)[1];
|
|
(*p) += 2;
|
|
|
|
if( (int)( end - *p ) < n )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
if( ( ret = mbedtls_mpi_read_binary( X, *p, n ) ) != 0 )
|
|
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_READ_PARAMS_FAILED, ret ) );
|
|
|
|
(*p) += n;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Verify sanity of parameter with regards to P
|
|
*
|
|
* Parameter should be: 2 <= public_param <= P - 2
|
|
*
|
|
* This means that we need to return an error if
|
|
* public_param < 2 or public_param > P-2
|
|
*
|
|
* For more information on the attack, see:
|
|
* http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf
|
|
* http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643
|
|
*/
|
|
static int dhm_check_range( const mbedtls_mpi *param, const mbedtls_mpi *P )
|
|
{
|
|
mbedtls_mpi U;
|
|
int ret = 0;
|
|
|
|
mbedtls_mpi_init( &U );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &U, P, 2 ) );
|
|
|
|
if( mbedtls_mpi_cmp_int( param, 2 ) < 0 ||
|
|
mbedtls_mpi_cmp_mpi( param, &U ) > 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
|
|
}
|
|
|
|
cleanup:
|
|
mbedtls_mpi_free( &U );
|
|
return( ret );
|
|
}
|
|
|
|
void mbedtls_dhm_init( mbedtls_dhm_context *ctx )
|
|
{
|
|
memset( ctx, 0, sizeof( mbedtls_dhm_context ) );
|
|
}
|
|
|
|
size_t mbedtls_dhm_get_bitlen( const mbedtls_dhm_context *ctx )
|
|
{
|
|
return( mbedtls_mpi_bitlen( &ctx->P ) );
|
|
}
|
|
|
|
size_t mbedtls_dhm_get_len( const mbedtls_dhm_context *ctx )
|
|
{
|
|
return( mbedtls_mpi_size( &ctx->P ) );
|
|
}
|
|
|
|
int mbedtls_dhm_get_value( const mbedtls_dhm_context *ctx,
|
|
mbedtls_dhm_parameter param,
|
|
mbedtls_mpi *dest )
|
|
{
|
|
const mbedtls_mpi *src = NULL;
|
|
switch( param )
|
|
{
|
|
case MBEDTLS_DHM_PARAM_P:
|
|
src = &ctx->P;
|
|
break;
|
|
case MBEDTLS_DHM_PARAM_G:
|
|
src = &ctx->G;
|
|
break;
|
|
case MBEDTLS_DHM_PARAM_X:
|
|
src = &ctx->X;
|
|
break;
|
|
case MBEDTLS_DHM_PARAM_GX:
|
|
src = &ctx->GX;
|
|
break;
|
|
case MBEDTLS_DHM_PARAM_GY:
|
|
src = &ctx->GY;
|
|
break;
|
|
case MBEDTLS_DHM_PARAM_K:
|
|
src = &ctx->K;
|
|
break;
|
|
default:
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
}
|
|
return( mbedtls_mpi_copy( dest, src ) );
|
|
}
|
|
|
|
/*
|
|
* Parse the ServerKeyExchange parameters
|
|
*/
|
|
int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx,
|
|
unsigned char **p,
|
|
const unsigned char *end )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
if( ( ret = dhm_read_bignum( &ctx->P, p, end ) ) != 0 ||
|
|
( ret = dhm_read_bignum( &ctx->G, p, end ) ) != 0 ||
|
|
( ret = dhm_read_bignum( &ctx->GY, p, end ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
|
|
return( ret );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Pick a random R in the range [2, M-2] for blinding or key generation.
|
|
*/
|
|
static int dhm_random_below( mbedtls_mpi *R, const mbedtls_mpi *M,
|
|
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
|
|
{
|
|
int ret;
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_random( R, 3, M, f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( R, R, 1 ) );
|
|
|
|
cleanup:
|
|
return( ret );
|
|
}
|
|
|
|
static int dhm_make_common( mbedtls_dhm_context *ctx, int x_size,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng )
|
|
{
|
|
int ret = 0;
|
|
|
|
if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
if( x_size < 0 )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
if( (unsigned) x_size < mbedtls_mpi_size( &ctx->P ) )
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng ) );
|
|
}
|
|
else
|
|
{
|
|
/* Generate X as large as possible ( <= P - 2 ) */
|
|
ret = dhm_random_below( &ctx->X, &ctx->P, f_rng, p_rng );
|
|
if( ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE )
|
|
return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Calculate GX = G^X mod P
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
|
|
&ctx->P , &ctx->RP ) );
|
|
|
|
if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
|
|
return( ret );
|
|
|
|
cleanup:
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Setup and write the ServerKeyExchange parameters
|
|
*/
|
|
int mbedtls_dhm_make_params( mbedtls_dhm_context *ctx, int x_size,
|
|
unsigned char *output, size_t *olen,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng )
|
|
{
|
|
int ret;
|
|
size_t n1, n2, n3;
|
|
unsigned char *p;
|
|
|
|
ret = dhm_make_common( ctx, x_size, f_rng, p_rng );
|
|
if( ret != 0 )
|
|
goto cleanup;
|
|
|
|
/*
|
|
* Export P, G, GX. RFC 5246 §4.4 states that "leading zero octets are
|
|
* not required". We omit leading zeros for compactness.
|
|
*/
|
|
#define DHM_MPI_EXPORT( X, n ) \
|
|
do { \
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( ( X ), \
|
|
p + 2, \
|
|
( n ) ) ); \
|
|
*p++ = MBEDTLS_BYTE_1( n ); \
|
|
*p++ = MBEDTLS_BYTE_0( n ); \
|
|
p += ( n ); \
|
|
} while( 0 )
|
|
|
|
n1 = mbedtls_mpi_size( &ctx->P );
|
|
n2 = mbedtls_mpi_size( &ctx->G );
|
|
n3 = mbedtls_mpi_size( &ctx->GX );
|
|
|
|
p = output;
|
|
DHM_MPI_EXPORT( &ctx->P , n1 );
|
|
DHM_MPI_EXPORT( &ctx->G , n2 );
|
|
DHM_MPI_EXPORT( &ctx->GX, n3 );
|
|
|
|
*olen = p - output;
|
|
|
|
cleanup:
|
|
if( ret != 0 && ret > -128 )
|
|
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED, ret );
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Set prime modulus and generator
|
|
*/
|
|
int mbedtls_dhm_set_group( mbedtls_dhm_context *ctx,
|
|
const mbedtls_mpi *P,
|
|
const mbedtls_mpi *G )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
if( ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ||
|
|
( ret = mbedtls_mpi_copy( &ctx->G, G ) ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_SET_GROUP_FAILED, ret ) );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Import the peer's public value G^Y
|
|
*/
|
|
int mbedtls_dhm_read_public( mbedtls_dhm_context *ctx,
|
|
const unsigned char *input, size_t ilen )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
if( ilen < 1 || ilen > mbedtls_dhm_get_len( ctx ) )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
if( ( ret = mbedtls_mpi_read_binary( &ctx->GY, input, ilen ) ) != 0 )
|
|
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED, ret ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Create own private value X and export G^X
|
|
*/
|
|
int mbedtls_dhm_make_public( mbedtls_dhm_context *ctx, int x_size,
|
|
unsigned char *output, size_t olen,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng )
|
|
{
|
|
int ret;
|
|
|
|
if( olen < 1 || olen > mbedtls_dhm_get_len( ctx ) )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
ret = dhm_make_common( ctx, x_size, f_rng, p_rng );
|
|
if( ret == MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED )
|
|
return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED );
|
|
if( ret != 0 )
|
|
goto cleanup;
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->GX, output, olen ) );
|
|
|
|
cleanup:
|
|
if( ret != 0 && ret > -128 )
|
|
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED, ret );
|
|
return( ret );
|
|
}
|
|
|
|
|
|
/*
|
|
* Use the blinding method and optimisation suggested in section 10 of:
|
|
* KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
|
|
* DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
|
|
* Berlin Heidelberg, 1996. p. 104-113.
|
|
*/
|
|
static int dhm_update_blinding( mbedtls_dhm_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
|
|
{
|
|
int ret;
|
|
mbedtls_mpi R;
|
|
|
|
mbedtls_mpi_init( &R );
|
|
|
|
/*
|
|
* Don't use any blinding the first time a particular X is used,
|
|
* but remember it to use blinding next time.
|
|
*/
|
|
if( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->pX ) != 0 )
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &ctx->pX, &ctx->X ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vi, 1 ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vf, 1 ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Ok, we need blinding. Can we re-use existing values?
|
|
* If yes, just update them by squaring them.
|
|
*/
|
|
if( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 )
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->P ) );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* We need to generate blinding values from scratch
|
|
*/
|
|
|
|
/* Vi = random( 2, P-2 ) */
|
|
MBEDTLS_MPI_CHK( dhm_random_below( &ctx->Vi, &ctx->P, f_rng, p_rng ) );
|
|
|
|
/* Vf = Vi^-X mod P
|
|
* First compute Vi^-1 = R * (R Vi)^-1, (avoiding leaks from inv_mod),
|
|
* then elevate to the Xth power. */
|
|
MBEDTLS_MPI_CHK( dhm_random_below( &R, &ctx->P, f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vi, &R ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vf, &ctx->Vf, &ctx->P ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &R ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP ) );
|
|
|
|
cleanup:
|
|
mbedtls_mpi_free( &R );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Derive and export the shared secret (G^Y)^X mod P
|
|
*/
|
|
int mbedtls_dhm_calc_secret( mbedtls_dhm_context *ctx,
|
|
unsigned char *output, size_t output_size, size_t *olen,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
mbedtls_mpi GYb;
|
|
|
|
if( f_rng == NULL )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
if( output_size < mbedtls_dhm_get_len( ctx ) )
|
|
return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
|
|
|
|
if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
|
|
return( ret );
|
|
|
|
mbedtls_mpi_init( &GYb );
|
|
|
|
/* Blind peer's value */
|
|
MBEDTLS_MPI_CHK( dhm_update_blinding( ctx, f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &GYb, &ctx->GY, &ctx->Vi ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &GYb, &GYb, &ctx->P ) );
|
|
|
|
/* Do modular exponentiation */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->K, &GYb, &ctx->X,
|
|
&ctx->P, &ctx->RP ) );
|
|
|
|
/* Unblind secret value */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->K, &ctx->K, &ctx->Vf ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->K, &ctx->K, &ctx->P ) );
|
|
|
|
/* Output the secret without any leading zero byte. This is mandatory
|
|
* for TLS per RFC 5246 §8.1.2. */
|
|
*olen = mbedtls_mpi_size( &ctx->K );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->K, output, *olen ) );
|
|
|
|
cleanup:
|
|
mbedtls_mpi_free( &GYb );
|
|
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_CALC_SECRET_FAILED, ret ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Free the components of a DHM key
|
|
*/
|
|
void mbedtls_dhm_free( mbedtls_dhm_context *ctx )
|
|
{
|
|
if( ctx == NULL )
|
|
return;
|
|
|
|
mbedtls_mpi_free( &ctx->pX );
|
|
mbedtls_mpi_free( &ctx->Vf );
|
|
mbedtls_mpi_free( &ctx->Vi );
|
|
mbedtls_mpi_free( &ctx->RP );
|
|
mbedtls_mpi_free( &ctx->K );
|
|
mbedtls_mpi_free( &ctx->GY );
|
|
mbedtls_mpi_free( &ctx->GX );
|
|
mbedtls_mpi_free( &ctx->X );
|
|
mbedtls_mpi_free( &ctx->G );
|
|
mbedtls_mpi_free( &ctx->P );
|
|
|
|
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_dhm_context ) );
|
|
}
|
|
|
|
#if defined(MBEDTLS_ASN1_PARSE_C)
|
|
/*
|
|
* Parse DHM parameters
|
|
*/
|
|
int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
|
|
size_t dhminlen )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t len;
|
|
unsigned char *p, *end;
|
|
#if defined(MBEDTLS_PEM_PARSE_C)
|
|
mbedtls_pem_context pem;
|
|
#endif /* MBEDTLS_PEM_PARSE_C */
|
|
|
|
#if defined(MBEDTLS_PEM_PARSE_C)
|
|
mbedtls_pem_init( &pem );
|
|
|
|
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
|
|
if( dhminlen == 0 || dhmin[dhminlen - 1] != '\0' )
|
|
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
|
|
else
|
|
ret = mbedtls_pem_read_buffer( &pem,
|
|
"-----BEGIN DH PARAMETERS-----",
|
|
"-----END DH PARAMETERS-----",
|
|
dhmin, NULL, 0, &dhminlen );
|
|
|
|
if( ret == 0 )
|
|
{
|
|
/*
|
|
* Was PEM encoded
|
|
*/
|
|
dhminlen = pem.buflen;
|
|
}
|
|
else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
|
|
goto exit;
|
|
|
|
p = ( ret == 0 ) ? pem.buf : (unsigned char *) dhmin;
|
|
#else
|
|
p = (unsigned char *) dhmin;
|
|
#endif /* MBEDTLS_PEM_PARSE_C */
|
|
end = p + dhminlen;
|
|
|
|
/*
|
|
* DHParams ::= SEQUENCE {
|
|
* prime INTEGER, -- P
|
|
* generator INTEGER, -- g
|
|
* privateValueLength INTEGER OPTIONAL
|
|
* }
|
|
*/
|
|
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
|
|
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_INVALID_FORMAT, ret );
|
|
goto exit;
|
|
}
|
|
|
|
end = p + len;
|
|
|
|
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->P ) ) != 0 ||
|
|
( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->G ) ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_INVALID_FORMAT, ret );
|
|
goto exit;
|
|
}
|
|
|
|
if( p != end )
|
|
{
|
|
/* This might be the optional privateValueLength.
|
|
* If so, we can cleanly discard it */
|
|
mbedtls_mpi rec;
|
|
mbedtls_mpi_init( &rec );
|
|
ret = mbedtls_asn1_get_mpi( &p, end, &rec );
|
|
mbedtls_mpi_free( &rec );
|
|
if ( ret != 0 )
|
|
{
|
|
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_INVALID_FORMAT, ret );
|
|
goto exit;
|
|
}
|
|
if ( p != end )
|
|
{
|
|
ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_DHM_INVALID_FORMAT,
|
|
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
exit:
|
|
#if defined(MBEDTLS_PEM_PARSE_C)
|
|
mbedtls_pem_free( &pem );
|
|
#endif
|
|
if( ret != 0 )
|
|
mbedtls_dhm_free( dhm );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
#if defined(MBEDTLS_FS_IO)
|
|
/*
|
|
* Load all data from a file into a given buffer.
|
|
*
|
|
* The file is expected to contain either PEM or DER encoded data.
|
|
* A terminating null byte is always appended. It is included in the announced
|
|
* length only if the data looks like it is PEM encoded.
|
|
*/
|
|
static int load_file( const char *path, unsigned char **buf, size_t *n )
|
|
{
|
|
FILE *f;
|
|
long size;
|
|
|
|
if( ( f = fopen( path, "rb" ) ) == NULL )
|
|
return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
|
|
/* The data loaded here is public, so don't bother disabling buffering. */
|
|
|
|
fseek( f, 0, SEEK_END );
|
|
if( ( size = ftell( f ) ) == -1 )
|
|
{
|
|
fclose( f );
|
|
return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
|
|
}
|
|
fseek( f, 0, SEEK_SET );
|
|
|
|
*n = (size_t) size;
|
|
|
|
if( *n + 1 == 0 ||
|
|
( *buf = mbedtls_calloc( 1, *n + 1 ) ) == NULL )
|
|
{
|
|
fclose( f );
|
|
return( MBEDTLS_ERR_DHM_ALLOC_FAILED );
|
|
}
|
|
|
|
if( fread( *buf, 1, *n, f ) != *n )
|
|
{
|
|
fclose( f );
|
|
|
|
mbedtls_platform_zeroize( *buf, *n + 1 );
|
|
mbedtls_free( *buf );
|
|
|
|
return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
|
|
}
|
|
|
|
fclose( f );
|
|
|
|
(*buf)[*n] = '\0';
|
|
|
|
if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL )
|
|
++*n;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Load and parse DHM parameters
|
|
*/
|
|
int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t n;
|
|
unsigned char *buf;
|
|
|
|
if( ( ret = load_file( path, &buf, &n ) ) != 0 )
|
|
return( ret );
|
|
|
|
ret = mbedtls_dhm_parse_dhm( dhm, buf, n );
|
|
|
|
mbedtls_platform_zeroize( buf, n );
|
|
mbedtls_free( buf );
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_FS_IO */
|
|
#endif /* MBEDTLS_ASN1_PARSE_C */
|
|
#endif /* MBEDTLS_DHM_ALT */
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
|
|
#if defined(MBEDTLS_PEM_PARSE_C)
|
|
static const char mbedtls_test_dhm_params[] =
|
|
"-----BEGIN DH PARAMETERS-----\r\n"
|
|
"MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n"
|
|
"1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n"
|
|
"9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n"
|
|
"-----END DH PARAMETERS-----\r\n";
|
|
#else /* MBEDTLS_PEM_PARSE_C */
|
|
static const char mbedtls_test_dhm_params[] = {
|
|
0x30, 0x81, 0x87, 0x02, 0x81, 0x81, 0x00, 0x9e, 0x35, 0xf4, 0x30, 0x44,
|
|
0x3a, 0x09, 0x90, 0x4f, 0x3a, 0x39, 0xa9, 0x79, 0x79, 0x7d, 0x07, 0x0d,
|
|
0xf5, 0x33, 0x78, 0xe7, 0x9c, 0x24, 0x38, 0xbe, 0xf4, 0xe7, 0x61, 0xf3,
|
|
0xc7, 0x14, 0x55, 0x33, 0x28, 0x58, 0x9b, 0x04, 0x1c, 0x80, 0x9b, 0xe1,
|
|
0xd6, 0xc6, 0xb5, 0xf1, 0xfc, 0x9f, 0x47, 0xd3, 0xa2, 0x54, 0x43, 0x18,
|
|
0x82, 0x53, 0xa9, 0x92, 0xa5, 0x68, 0x18, 0xb3, 0x7b, 0xa9, 0xde, 0x5a,
|
|
0x40, 0xd3, 0x62, 0xe5, 0x6e, 0xff, 0x0b, 0xe5, 0x41, 0x74, 0x74, 0xc1,
|
|
0x25, 0xc1, 0x99, 0x27, 0x2c, 0x8f, 0xe4, 0x1d, 0xea, 0x73, 0x3d, 0xf6,
|
|
0xf6, 0x62, 0xc9, 0x2a, 0xe7, 0x65, 0x56, 0xe7, 0x55, 0xd1, 0x0c, 0x64,
|
|
0xe6, 0xa5, 0x09, 0x68, 0xf6, 0x7f, 0xc6, 0xea, 0x73, 0xd0, 0xdc, 0xa8,
|
|
0x56, 0x9b, 0xe2, 0xba, 0x20, 0x4e, 0x23, 0x58, 0x0d, 0x8b, 0xca, 0x2f,
|
|
0x49, 0x75, 0xb3, 0x02, 0x01, 0x02 };
|
|
#endif /* MBEDTLS_PEM_PARSE_C */
|
|
|
|
static const size_t mbedtls_test_dhm_params_len = sizeof( mbedtls_test_dhm_params );
|
|
|
|
/*
|
|
* Checkup routine
|
|
*/
|
|
int mbedtls_dhm_self_test( int verbose )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
mbedtls_dhm_context dhm;
|
|
|
|
mbedtls_dhm_init( &dhm );
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( " DHM parameter load: " );
|
|
|
|
if( ( ret = mbedtls_dhm_parse_dhm( &dhm,
|
|
(const unsigned char *) mbedtls_test_dhm_params,
|
|
mbedtls_test_dhm_params_len ) ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto exit;
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n\n" );
|
|
|
|
exit:
|
|
mbedtls_dhm_free( &dhm );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#endif /* MBEDTLS_DHM_C */
|