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diff --git a/library/dhm.c b/library/dhm.c
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+/*
+ * 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 */