mirror of
https://github.com/reactos/reactos.git
synced 2024-08-28 22:28:36 +00:00
2540 lines
76 KiB
C
2540 lines
76 KiB
C
/*
|
|
* The RSA public-key cryptosystem
|
|
*
|
|
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
|
|
* SPDX-License-Identifier: GPL-2.0
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* This file is part of mbed TLS (https://tls.mbed.org)
|
|
*/
|
|
|
|
/*
|
|
* The following sources were referenced in the design of this implementation
|
|
* of the RSA algorithm:
|
|
*
|
|
* [1] A method for obtaining digital signatures and public-key cryptosystems
|
|
* R Rivest, A Shamir, and L Adleman
|
|
* http://people.csail.mit.edu/rivest/pubs.html#RSA78
|
|
*
|
|
* [2] Handbook of Applied Cryptography - 1997, Chapter 8
|
|
* Menezes, van Oorschot and Vanstone
|
|
*
|
|
* [3] Malware Guard Extension: Using SGX to Conceal Cache Attacks
|
|
* Michael Schwarz, Samuel Weiser, Daniel Gruss, Clémentine Maurice and
|
|
* Stefan Mangard
|
|
* https://arxiv.org/abs/1702.08719v2
|
|
*
|
|
*/
|
|
|
|
#if !defined(MBEDTLS_CONFIG_FILE)
|
|
#include "mbedtls/config.h"
|
|
#else
|
|
#include MBEDTLS_CONFIG_FILE
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_RSA_C)
|
|
|
|
#include "mbedtls/rsa.h"
|
|
#include "mbedtls/rsa_internal.h"
|
|
#include "mbedtls/oid.h"
|
|
|
|
#include <string.h>
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
#include "mbedtls/md.h"
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__)
|
|
#include <stdlib.h>
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PLATFORM_C)
|
|
#include "mbedtls/platform.h"
|
|
#else
|
|
#include <stdio.h>
|
|
#define mbedtls_printf printf
|
|
#define mbedtls_calloc calloc
|
|
#define mbedtls_free free
|
|
#endif
|
|
|
|
#if !defined(MBEDTLS_RSA_ALT)
|
|
|
|
/* Implementation that should never be optimized out by the compiler */
|
|
static void mbedtls_zeroize( void *v, size_t n ) {
|
|
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
|
|
}
|
|
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
/* constant-time buffer comparison */
|
|
static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
|
|
{
|
|
size_t i;
|
|
const unsigned char *A = (const unsigned char *) a;
|
|
const unsigned char *B = (const unsigned char *) b;
|
|
unsigned char diff = 0;
|
|
|
|
for( i = 0; i < n; i++ )
|
|
diff |= A[i] ^ B[i];
|
|
|
|
return( diff );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V15 */
|
|
|
|
int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
|
|
const mbedtls_mpi *N,
|
|
const mbedtls_mpi *P, const mbedtls_mpi *Q,
|
|
const mbedtls_mpi *D, const mbedtls_mpi *E )
|
|
{
|
|
int ret;
|
|
|
|
if( ( N != NULL && ( ret = mbedtls_mpi_copy( &ctx->N, N ) ) != 0 ) ||
|
|
( P != NULL && ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ) ||
|
|
( Q != NULL && ( ret = mbedtls_mpi_copy( &ctx->Q, Q ) ) != 0 ) ||
|
|
( D != NULL && ( ret = mbedtls_mpi_copy( &ctx->D, D ) ) != 0 ) ||
|
|
( E != NULL && ( ret = mbedtls_mpi_copy( &ctx->E, E ) ) != 0 ) )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
}
|
|
|
|
if( N != NULL )
|
|
ctx->len = mbedtls_mpi_size( &ctx->N );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_rsa_import_raw( mbedtls_rsa_context *ctx,
|
|
unsigned char const *N, size_t N_len,
|
|
unsigned char const *P, size_t P_len,
|
|
unsigned char const *Q, size_t Q_len,
|
|
unsigned char const *D, size_t D_len,
|
|
unsigned char const *E, size_t E_len )
|
|
{
|
|
int ret = 0;
|
|
|
|
if( N != NULL )
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->N, N, N_len ) );
|
|
ctx->len = mbedtls_mpi_size( &ctx->N );
|
|
}
|
|
|
|
if( P != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->P, P, P_len ) );
|
|
|
|
if( Q != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->Q, Q, Q_len ) );
|
|
|
|
if( D != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->D, D, D_len ) );
|
|
|
|
if( E != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->E, E, E_len ) );
|
|
|
|
cleanup:
|
|
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Checks whether the context fields are set in such a way
|
|
* that the RSA primitives will be able to execute without error.
|
|
* It does *not* make guarantees for consistency of the parameters.
|
|
*/
|
|
static int rsa_check_context( mbedtls_rsa_context const *ctx, int is_priv,
|
|
int blinding_needed )
|
|
{
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
/* blinding_needed is only used for NO_CRT to decide whether
|
|
* P,Q need to be present or not. */
|
|
((void) blinding_needed);
|
|
#endif
|
|
|
|
if( ctx->len != mbedtls_mpi_size( &ctx->N ) ||
|
|
ctx->len > MBEDTLS_MPI_MAX_SIZE )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
|
|
/*
|
|
* 1. Modular exponentiation needs positive, odd moduli.
|
|
*/
|
|
|
|
/* Modular exponentiation wrt. N is always used for
|
|
* RSA public key operations. */
|
|
if( mbedtls_mpi_cmp_int( &ctx->N, 0 ) <= 0 ||
|
|
mbedtls_mpi_get_bit( &ctx->N, 0 ) == 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
/* Modular exponentiation for P and Q is only
|
|
* used for private key operations and if CRT
|
|
* is used. */
|
|
if( is_priv &&
|
|
( mbedtls_mpi_cmp_int( &ctx->P, 0 ) <= 0 ||
|
|
mbedtls_mpi_get_bit( &ctx->P, 0 ) == 0 ||
|
|
mbedtls_mpi_cmp_int( &ctx->Q, 0 ) <= 0 ||
|
|
mbedtls_mpi_get_bit( &ctx->Q, 0 ) == 0 ) )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
#endif /* !MBEDTLS_RSA_NO_CRT */
|
|
|
|
/*
|
|
* 2. Exponents must be positive
|
|
*/
|
|
|
|
/* Always need E for public key operations */
|
|
if( mbedtls_mpi_cmp_int( &ctx->E, 0 ) <= 0 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
#if defined(MBEDTLS_RSA_NO_CRT)
|
|
/* For private key operations, use D or DP & DQ
|
|
* as (unblinded) exponents. */
|
|
if( is_priv && mbedtls_mpi_cmp_int( &ctx->D, 0 ) <= 0 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
#else
|
|
if( is_priv &&
|
|
( mbedtls_mpi_cmp_int( &ctx->DP, 0 ) <= 0 ||
|
|
mbedtls_mpi_cmp_int( &ctx->DQ, 0 ) <= 0 ) )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
#endif /* MBEDTLS_RSA_NO_CRT */
|
|
|
|
/* Blinding shouldn't make exponents negative either,
|
|
* so check that P, Q >= 1 if that hasn't yet been
|
|
* done as part of 1. */
|
|
#if defined(MBEDTLS_RSA_NO_CRT)
|
|
if( is_priv && blinding_needed &&
|
|
( mbedtls_mpi_cmp_int( &ctx->P, 0 ) <= 0 ||
|
|
mbedtls_mpi_cmp_int( &ctx->Q, 0 ) <= 0 ) )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
#endif
|
|
|
|
/* It wouldn't lead to an error if it wasn't satisfied,
|
|
* but check for QP >= 1 nonetheless. */
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
if( is_priv &&
|
|
mbedtls_mpi_cmp_int( &ctx->QP, 0 ) <= 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
#endif
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
|
|
{
|
|
int ret = 0;
|
|
|
|
const int have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 );
|
|
const int have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 );
|
|
const int have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 );
|
|
const int have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
|
|
const int have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 );
|
|
|
|
/*
|
|
* Check whether provided parameters are enough
|
|
* to deduce all others. The following incomplete
|
|
* parameter sets for private keys are supported:
|
|
*
|
|
* (1) P, Q missing.
|
|
* (2) D and potentially N missing.
|
|
*
|
|
*/
|
|
|
|
const int n_missing = have_P && have_Q && have_D && have_E;
|
|
const int pq_missing = have_N && !have_P && !have_Q && have_D && have_E;
|
|
const int d_missing = have_P && have_Q && !have_D && have_E;
|
|
const int is_pub = have_N && !have_P && !have_Q && !have_D && have_E;
|
|
|
|
/* These three alternatives are mutually exclusive */
|
|
const int is_priv = n_missing || pq_missing || d_missing;
|
|
|
|
if( !is_priv && !is_pub )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
/*
|
|
* Step 1: Deduce N if P, Q are provided.
|
|
*/
|
|
|
|
if( !have_N && have_P && have_Q )
|
|
{
|
|
if( ( ret = mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P,
|
|
&ctx->Q ) ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
}
|
|
|
|
ctx->len = mbedtls_mpi_size( &ctx->N );
|
|
}
|
|
|
|
/*
|
|
* Step 2: Deduce and verify all remaining core parameters.
|
|
*/
|
|
|
|
if( pq_missing )
|
|
{
|
|
ret = mbedtls_rsa_deduce_primes( &ctx->N, &ctx->E, &ctx->D,
|
|
&ctx->P, &ctx->Q );
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
|
|
}
|
|
else if( d_missing )
|
|
{
|
|
if( ( ret = mbedtls_rsa_deduce_private_exponent( &ctx->P,
|
|
&ctx->Q,
|
|
&ctx->E,
|
|
&ctx->D ) ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Step 3: Deduce all additional parameters specific
|
|
* to our current RSA implementation.
|
|
*/
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
if( is_priv )
|
|
{
|
|
ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
|
|
&ctx->DP, &ctx->DQ, &ctx->QP );
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
}
|
|
#endif /* MBEDTLS_RSA_NO_CRT */
|
|
|
|
/*
|
|
* Step 3: Basic sanity checks
|
|
*/
|
|
|
|
return( rsa_check_context( ctx, is_priv, 1 ) );
|
|
}
|
|
|
|
int mbedtls_rsa_export_raw( const mbedtls_rsa_context *ctx,
|
|
unsigned char *N, size_t N_len,
|
|
unsigned char *P, size_t P_len,
|
|
unsigned char *Q, size_t Q_len,
|
|
unsigned char *D, size_t D_len,
|
|
unsigned char *E, size_t E_len )
|
|
{
|
|
int ret = 0;
|
|
|
|
/* Check if key is private or public */
|
|
const int is_priv =
|
|
mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0;
|
|
|
|
if( !is_priv )
|
|
{
|
|
/* If we're trying to export private parameters for a public key,
|
|
* something must be wrong. */
|
|
if( P != NULL || Q != NULL || D != NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
}
|
|
|
|
if( N != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->N, N, N_len ) );
|
|
|
|
if( P != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->P, P, P_len ) );
|
|
|
|
if( Q != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->Q, Q, Q_len ) );
|
|
|
|
if( D != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->D, D, D_len ) );
|
|
|
|
if( E != NULL )
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->E, E, E_len ) );
|
|
|
|
cleanup:
|
|
|
|
return( ret );
|
|
}
|
|
|
|
int mbedtls_rsa_export( const mbedtls_rsa_context *ctx,
|
|
mbedtls_mpi *N, mbedtls_mpi *P, mbedtls_mpi *Q,
|
|
mbedtls_mpi *D, mbedtls_mpi *E )
|
|
{
|
|
int ret;
|
|
|
|
/* Check if key is private or public */
|
|
int is_priv =
|
|
mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0;
|
|
|
|
if( !is_priv )
|
|
{
|
|
/* If we're trying to export private parameters for a public key,
|
|
* something must be wrong. */
|
|
if( P != NULL || Q != NULL || D != NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
}
|
|
|
|
/* Export all requested core parameters. */
|
|
|
|
if( ( N != NULL && ( ret = mbedtls_mpi_copy( N, &ctx->N ) ) != 0 ) ||
|
|
( P != NULL && ( ret = mbedtls_mpi_copy( P, &ctx->P ) ) != 0 ) ||
|
|
( Q != NULL && ( ret = mbedtls_mpi_copy( Q, &ctx->Q ) ) != 0 ) ||
|
|
( D != NULL && ( ret = mbedtls_mpi_copy( D, &ctx->D ) ) != 0 ) ||
|
|
( E != NULL && ( ret = mbedtls_mpi_copy( E, &ctx->E ) ) != 0 ) )
|
|
{
|
|
return( ret );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Export CRT parameters
|
|
* This must also be implemented if CRT is not used, for being able to
|
|
* write DER encoded RSA keys. The helper function mbedtls_rsa_deduce_crt
|
|
* can be used in this case.
|
|
*/
|
|
int mbedtls_rsa_export_crt( const mbedtls_rsa_context *ctx,
|
|
mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP )
|
|
{
|
|
int ret;
|
|
|
|
/* Check if key is private or public */
|
|
int is_priv =
|
|
mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 &&
|
|
mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0;
|
|
|
|
if( !is_priv )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
/* Export all requested blinding parameters. */
|
|
if( ( DP != NULL && ( ret = mbedtls_mpi_copy( DP, &ctx->DP ) ) != 0 ) ||
|
|
( DQ != NULL && ( ret = mbedtls_mpi_copy( DQ, &ctx->DQ ) ) != 0 ) ||
|
|
( QP != NULL && ( ret = mbedtls_mpi_copy( QP, &ctx->QP ) ) != 0 ) )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
}
|
|
#else
|
|
if( ( ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
|
|
DP, DQ, QP ) ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
|
|
}
|
|
#endif
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Initialize an RSA context
|
|
*/
|
|
void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
|
|
int padding,
|
|
int hash_id )
|
|
{
|
|
memset( ctx, 0, sizeof( mbedtls_rsa_context ) );
|
|
|
|
mbedtls_rsa_set_padding( ctx, padding, hash_id );
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
mbedtls_mutex_init( &ctx->mutex );
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Set padding for an existing RSA context
|
|
*/
|
|
void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding, int hash_id )
|
|
{
|
|
ctx->padding = padding;
|
|
ctx->hash_id = hash_id;
|
|
}
|
|
|
|
/*
|
|
* Get length in bytes of RSA modulus
|
|
*/
|
|
|
|
size_t mbedtls_rsa_get_len( const mbedtls_rsa_context *ctx )
|
|
{
|
|
return( ctx->len );
|
|
}
|
|
|
|
|
|
#if defined(MBEDTLS_GENPRIME)
|
|
|
|
/*
|
|
* Generate an RSA keypair
|
|
*/
|
|
int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
unsigned int nbits, int exponent )
|
|
{
|
|
int ret;
|
|
mbedtls_mpi H, G;
|
|
|
|
if( f_rng == NULL || nbits < 128 || exponent < 3 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
if( nbits % 2 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
mbedtls_mpi_init( &H );
|
|
mbedtls_mpi_init( &G );
|
|
|
|
/*
|
|
* find primes P and Q with Q < P so that:
|
|
* GCD( E, (P-1)*(Q-1) ) == 1
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->E, exponent ) );
|
|
|
|
do
|
|
{
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, nbits >> 1, 0,
|
|
f_rng, p_rng ) );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, nbits >> 1, 0,
|
|
f_rng, p_rng ) );
|
|
|
|
if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 )
|
|
continue;
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
|
|
if( mbedtls_mpi_bitlen( &ctx->N ) != nbits )
|
|
continue;
|
|
|
|
if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 )
|
|
mbedtls_mpi_swap( &ctx->P, &ctx->Q );
|
|
|
|
/* Temporarily replace P,Q by P-1, Q-1 */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->P, &ctx->P, 1 ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->Q, &ctx->Q, 1 ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &ctx->P, &ctx->Q ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) );
|
|
}
|
|
while( mbedtls_mpi_cmp_int( &G, 1 ) != 0 );
|
|
|
|
/* Restore P,Q */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->P, &ctx->P, 1 ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->Q, &ctx->Q, 1 ) );
|
|
|
|
ctx->len = mbedtls_mpi_size( &ctx->N );
|
|
|
|
/*
|
|
* D = E^-1 mod ((P-1)*(Q-1))
|
|
* DP = D mod (P - 1)
|
|
* DQ = D mod (Q - 1)
|
|
* QP = Q^-1 mod P
|
|
*/
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D, &ctx->E, &H ) );
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
|
|
&ctx->DP, &ctx->DQ, &ctx->QP ) );
|
|
#endif /* MBEDTLS_RSA_NO_CRT */
|
|
|
|
/* Double-check */
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_check_privkey( ctx ) );
|
|
|
|
cleanup:
|
|
|
|
mbedtls_mpi_free( &H );
|
|
mbedtls_mpi_free( &G );
|
|
|
|
if( ret != 0 )
|
|
{
|
|
mbedtls_rsa_free( ctx );
|
|
return( MBEDTLS_ERR_RSA_KEY_GEN_FAILED + ret );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#endif /* MBEDTLS_GENPRIME */
|
|
|
|
/*
|
|
* Check a public RSA key
|
|
*/
|
|
int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx )
|
|
{
|
|
if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) != 0 )
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
|
|
if( mbedtls_mpi_bitlen( &ctx->N ) < 128 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
}
|
|
|
|
if( mbedtls_mpi_get_bit( &ctx->E, 0 ) == 0 ||
|
|
mbedtls_mpi_bitlen( &ctx->E ) < 2 ||
|
|
mbedtls_mpi_cmp_mpi( &ctx->E, &ctx->N ) >= 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Check for the consistency of all fields in an RSA private key context
|
|
*/
|
|
int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx )
|
|
{
|
|
if( mbedtls_rsa_check_pubkey( ctx ) != 0 ||
|
|
rsa_check_context( ctx, 1 /* private */, 1 /* blinding */ ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
}
|
|
|
|
if( mbedtls_rsa_validate_params( &ctx->N, &ctx->P, &ctx->Q,
|
|
&ctx->D, &ctx->E, NULL, NULL ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
}
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
else if( mbedtls_rsa_validate_crt( &ctx->P, &ctx->Q, &ctx->D,
|
|
&ctx->DP, &ctx->DQ, &ctx->QP ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
}
|
|
#endif
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Check if contexts holding a public and private key match
|
|
*/
|
|
int mbedtls_rsa_check_pub_priv( const mbedtls_rsa_context *pub,
|
|
const mbedtls_rsa_context *prv )
|
|
{
|
|
if( mbedtls_rsa_check_pubkey( pub ) != 0 ||
|
|
mbedtls_rsa_check_privkey( prv ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
}
|
|
|
|
if( mbedtls_mpi_cmp_mpi( &pub->N, &prv->N ) != 0 ||
|
|
mbedtls_mpi_cmp_mpi( &pub->E, &prv->E ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Do an RSA public key operation
|
|
*/
|
|
int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
int ret;
|
|
size_t olen;
|
|
mbedtls_mpi T;
|
|
|
|
if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
mbedtls_mpi_init( &T );
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
|
|
return( ret );
|
|
#endif
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
|
|
|
|
if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
|
|
goto cleanup;
|
|
}
|
|
|
|
olen = ctx->len;
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->E, &ctx->N, &ctx->RN ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) );
|
|
|
|
cleanup:
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
|
|
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
|
|
#endif
|
|
|
|
mbedtls_mpi_free( &T );
|
|
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_RSA_PUBLIC_FAILED + ret );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Generate or update blinding values, see 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 rsa_prepare_blinding( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
|
|
{
|
|
int ret, count = 0;
|
|
|
|
if( ctx->Vf.p != NULL )
|
|
{
|
|
/* We already have blinding values, just update them by squaring */
|
|
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->N ) );
|
|
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->N ) );
|
|
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Unblinding value: Vf = random number, invertible mod N */
|
|
do {
|
|
if( count++ > 10 )
|
|
return( MBEDTLS_ERR_RSA_RNG_FAILED );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->Vf, ctx->len - 1, f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &ctx->Vi, &ctx->Vf, &ctx->N ) );
|
|
} while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 );
|
|
|
|
/* Blinding value: Vi = Vf^(-e) mod N */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vf, &ctx->N ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) );
|
|
|
|
|
|
cleanup:
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Exponent blinding supposed to prevent side-channel attacks using multiple
|
|
* traces of measurements to recover the RSA key. The more collisions are there,
|
|
* the more bits of the key can be recovered. See [3].
|
|
*
|
|
* Collecting n collisions with m bit long blinding value requires 2^(m-m/n)
|
|
* observations on avarage.
|
|
*
|
|
* For example with 28 byte blinding to achieve 2 collisions the adversary has
|
|
* to make 2^112 observations on avarage.
|
|
*
|
|
* (With the currently (as of 2017 April) known best algorithms breaking 2048
|
|
* bit RSA requires approximately as much time as trying out 2^112 random keys.
|
|
* Thus in this sense with 28 byte blinding the security is not reduced by
|
|
* side-channel attacks like the one in [3])
|
|
*
|
|
* This countermeasure does not help if the key recovery is possible with a
|
|
* single trace.
|
|
*/
|
|
#define RSA_EXPONENT_BLINDING 28
|
|
|
|
/*
|
|
* Do an RSA private key operation
|
|
*/
|
|
int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
int ret;
|
|
size_t olen;
|
|
|
|
/* Temporary holding the result */
|
|
mbedtls_mpi T;
|
|
|
|
/* Temporaries holding P-1, Q-1 and the
|
|
* exponent blinding factor, respectively. */
|
|
mbedtls_mpi P1, Q1, R;
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
/* Temporaries holding the results mod p resp. mod q. */
|
|
mbedtls_mpi TP, TQ;
|
|
|
|
/* Temporaries holding the blinded exponents for
|
|
* the mod p resp. mod q computation (if used). */
|
|
mbedtls_mpi DP_blind, DQ_blind;
|
|
|
|
/* Pointers to actual exponents to be used - either the unblinded
|
|
* or the blinded ones, depending on the presence of a PRNG. */
|
|
mbedtls_mpi *DP = &ctx->DP;
|
|
mbedtls_mpi *DQ = &ctx->DQ;
|
|
#else
|
|
/* Temporary holding the blinded exponent (if used). */
|
|
mbedtls_mpi D_blind;
|
|
|
|
/* Pointer to actual exponent to be used - either the unblinded
|
|
* or the blinded one, depending on the presence of a PRNG. */
|
|
mbedtls_mpi *D = &ctx->D;
|
|
#endif /* MBEDTLS_RSA_NO_CRT */
|
|
|
|
/* Temporaries holding the initial input and the double
|
|
* checked result; should be the same in the end. */
|
|
mbedtls_mpi I, C;
|
|
|
|
if( rsa_check_context( ctx, 1 /* private key checks */,
|
|
f_rng != NULL /* blinding y/n */ ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
|
|
return( ret );
|
|
#endif
|
|
|
|
/* MPI Initialization */
|
|
mbedtls_mpi_init( &T );
|
|
|
|
mbedtls_mpi_init( &P1 );
|
|
mbedtls_mpi_init( &Q1 );
|
|
mbedtls_mpi_init( &R );
|
|
|
|
if( f_rng != NULL )
|
|
{
|
|
#if defined(MBEDTLS_RSA_NO_CRT)
|
|
mbedtls_mpi_init( &D_blind );
|
|
#else
|
|
mbedtls_mpi_init( &DP_blind );
|
|
mbedtls_mpi_init( &DQ_blind );
|
|
#endif
|
|
}
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
mbedtls_mpi_init( &TP ); mbedtls_mpi_init( &TQ );
|
|
#endif
|
|
|
|
mbedtls_mpi_init( &I );
|
|
mbedtls_mpi_init( &C );
|
|
|
|
/* End of MPI initialization */
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
|
|
if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
|
|
goto cleanup;
|
|
}
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &I, &T ) );
|
|
|
|
if( f_rng != NULL )
|
|
{
|
|
/*
|
|
* Blinding
|
|
* T = T * Vi mod N
|
|
*/
|
|
MBEDTLS_MPI_CHK( rsa_prepare_blinding( ctx, f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vi ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
|
|
|
|
/*
|
|
* Exponent blinding
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) );
|
|
|
|
#if defined(MBEDTLS_RSA_NO_CRT)
|
|
/*
|
|
* D_blind = ( P - 1 ) * ( Q - 1 ) * R + D
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING,
|
|
f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &D_blind, &P1, &Q1 ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &D_blind, &D_blind, &R ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &D_blind, &D_blind, &ctx->D ) );
|
|
|
|
D = &D_blind;
|
|
#else
|
|
/*
|
|
* DP_blind = ( P - 1 ) * R + DP
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING,
|
|
f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DP_blind, &P1, &R ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &DP_blind, &DP_blind,
|
|
&ctx->DP ) );
|
|
|
|
DP = &DP_blind;
|
|
|
|
/*
|
|
* DQ_blind = ( Q - 1 ) * R + DQ
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING,
|
|
f_rng, p_rng ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DQ_blind, &Q1, &R ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &DQ_blind, &DQ_blind,
|
|
&ctx->DQ ) );
|
|
|
|
DQ = &DQ_blind;
|
|
#endif /* MBEDTLS_RSA_NO_CRT */
|
|
}
|
|
|
|
#if defined(MBEDTLS_RSA_NO_CRT)
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, D, &ctx->N, &ctx->RN ) );
|
|
#else
|
|
/*
|
|
* Faster decryption using the CRT
|
|
*
|
|
* TP = input ^ dP mod P
|
|
* TQ = input ^ dQ mod Q
|
|
*/
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &TP, &T, DP, &ctx->P, &ctx->RP ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &TQ, &T, DQ, &ctx->Q, &ctx->RQ ) );
|
|
|
|
/*
|
|
* T = (TP - TQ) * (Q^-1 mod P) mod P
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T, &TP, &TQ ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &TP, &T, &ctx->QP ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &TP, &ctx->P ) );
|
|
|
|
/*
|
|
* T = TQ + T * Q
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &TP, &T, &ctx->Q ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &T, &TQ, &TP ) );
|
|
#endif /* MBEDTLS_RSA_NO_CRT */
|
|
|
|
if( f_rng != NULL )
|
|
{
|
|
/*
|
|
* Unblind
|
|
* T = T * Vf mod N
|
|
*/
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vf ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
|
|
}
|
|
|
|
/* Verify the result to prevent glitching attacks. */
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &C, &T, &ctx->E,
|
|
&ctx->N, &ctx->RN ) );
|
|
if( mbedtls_mpi_cmp_mpi( &C, &I ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
|
|
goto cleanup;
|
|
}
|
|
|
|
olen = ctx->len;
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) );
|
|
|
|
cleanup:
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
|
|
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
|
|
#endif
|
|
|
|
mbedtls_mpi_free( &P1 );
|
|
mbedtls_mpi_free( &Q1 );
|
|
mbedtls_mpi_free( &R );
|
|
|
|
if( f_rng != NULL )
|
|
{
|
|
#if defined(MBEDTLS_RSA_NO_CRT)
|
|
mbedtls_mpi_free( &D_blind );
|
|
#else
|
|
mbedtls_mpi_free( &DP_blind );
|
|
mbedtls_mpi_free( &DQ_blind );
|
|
#endif
|
|
}
|
|
|
|
mbedtls_mpi_free( &T );
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
mbedtls_mpi_free( &TP ); mbedtls_mpi_free( &TQ );
|
|
#endif
|
|
|
|
mbedtls_mpi_free( &C );
|
|
mbedtls_mpi_free( &I );
|
|
|
|
if( ret != 0 )
|
|
return( MBEDTLS_ERR_RSA_PRIVATE_FAILED + ret );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
/**
|
|
* Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer.
|
|
*
|
|
* \param dst buffer to mask
|
|
* \param dlen length of destination buffer
|
|
* \param src source of the mask generation
|
|
* \param slen length of the source buffer
|
|
* \param md_ctx message digest context to use
|
|
*/
|
|
static int mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src,
|
|
size_t slen, mbedtls_md_context_t *md_ctx )
|
|
{
|
|
unsigned char mask[MBEDTLS_MD_MAX_SIZE];
|
|
unsigned char counter[4];
|
|
unsigned char *p;
|
|
unsigned int hlen;
|
|
size_t i, use_len;
|
|
int ret = 0;
|
|
|
|
memset( mask, 0, MBEDTLS_MD_MAX_SIZE );
|
|
memset( counter, 0, 4 );
|
|
|
|
hlen = mbedtls_md_get_size( md_ctx->md_info );
|
|
|
|
/* Generate and apply dbMask */
|
|
p = dst;
|
|
|
|
while( dlen > 0 )
|
|
{
|
|
use_len = hlen;
|
|
if( dlen < hlen )
|
|
use_len = dlen;
|
|
|
|
if( ( ret = mbedtls_md_starts( md_ctx ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = mbedtls_md_update( md_ctx, src, slen ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = mbedtls_md_update( md_ctx, counter, 4 ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = mbedtls_md_finish( md_ctx, mask ) ) != 0 )
|
|
goto exit;
|
|
|
|
for( i = 0; i < use_len; ++i )
|
|
*p++ ^= mask[i];
|
|
|
|
counter[3]++;
|
|
|
|
dlen -= use_len;
|
|
}
|
|
|
|
exit:
|
|
mbedtls_zeroize( mask, sizeof( mask ) );
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V21 */
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function
|
|
*/
|
|
int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
const unsigned char *label, size_t label_len,
|
|
size_t ilen,
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
size_t olen;
|
|
int ret;
|
|
unsigned char *p = output;
|
|
unsigned int hlen;
|
|
const mbedtls_md_info_t *md_info;
|
|
mbedtls_md_context_t md_ctx;
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
if( f_rng == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
|
|
if( md_info == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
olen = ctx->len;
|
|
hlen = mbedtls_md_get_size( md_info );
|
|
|
|
/* first comparison checks for overflow */
|
|
if( ilen + 2 * hlen + 2 < ilen || olen < ilen + 2 * hlen + 2 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
memset( output, 0, olen );
|
|
|
|
*p++ = 0;
|
|
|
|
/* Generate a random octet string seed */
|
|
if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 )
|
|
return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
|
|
|
|
p += hlen;
|
|
|
|
/* Construct DB */
|
|
if( ( ret = mbedtls_md( md_info, label, label_len, p ) ) != 0 )
|
|
return( ret );
|
|
p += hlen;
|
|
p += olen - 2 * hlen - 2 - ilen;
|
|
*p++ = 1;
|
|
memcpy( p, input, ilen );
|
|
|
|
mbedtls_md_init( &md_ctx );
|
|
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
|
|
goto exit;
|
|
|
|
/* maskedDB: Apply dbMask to DB */
|
|
if( ( ret = mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen,
|
|
&md_ctx ) ) != 0 )
|
|
goto exit;
|
|
|
|
/* maskedSeed: Apply seedMask to seed */
|
|
if( ( ret = mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1,
|
|
&md_ctx ) ) != 0 )
|
|
goto exit;
|
|
|
|
exit:
|
|
mbedtls_md_free( &md_ctx );
|
|
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
return( ( mode == MBEDTLS_RSA_PUBLIC )
|
|
? mbedtls_rsa_public( ctx, output, output )
|
|
: mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V21 */
|
|
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function
|
|
*/
|
|
int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode, size_t ilen,
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
size_t nb_pad, olen;
|
|
int ret;
|
|
unsigned char *p = output;
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
// We don't check p_rng because it won't be dereferenced here
|
|
if( f_rng == NULL || input == NULL || output == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
olen = ctx->len;
|
|
|
|
/* first comparison checks for overflow */
|
|
if( ilen + 11 < ilen || olen < ilen + 11 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
nb_pad = olen - 3 - ilen;
|
|
|
|
*p++ = 0;
|
|
if( mode == MBEDTLS_RSA_PUBLIC )
|
|
{
|
|
*p++ = MBEDTLS_RSA_CRYPT;
|
|
|
|
while( nb_pad-- > 0 )
|
|
{
|
|
int rng_dl = 100;
|
|
|
|
do {
|
|
ret = f_rng( p_rng, p, 1 );
|
|
} while( *p == 0 && --rng_dl && ret == 0 );
|
|
|
|
/* Check if RNG failed to generate data */
|
|
if( rng_dl == 0 || ret != 0 )
|
|
return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
|
|
|
|
p++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
*p++ = MBEDTLS_RSA_SIGN;
|
|
|
|
while( nb_pad-- > 0 )
|
|
*p++ = 0xFF;
|
|
}
|
|
|
|
*p++ = 0;
|
|
memcpy( p, input, ilen );
|
|
|
|
return( ( mode == MBEDTLS_RSA_PUBLIC )
|
|
? mbedtls_rsa_public( ctx, output, output )
|
|
: mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V15 */
|
|
|
|
/*
|
|
* Add the message padding, then do an RSA operation
|
|
*/
|
|
int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode, size_t ilen,
|
|
const unsigned char *input,
|
|
unsigned char *output )
|
|
{
|
|
switch( ctx->padding )
|
|
{
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
case MBEDTLS_RSA_PKCS_V15:
|
|
return mbedtls_rsa_rsaes_pkcs1_v15_encrypt( ctx, f_rng, p_rng, mode, ilen,
|
|
input, output );
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
case MBEDTLS_RSA_PKCS_V21:
|
|
return mbedtls_rsa_rsaes_oaep_encrypt( ctx, f_rng, p_rng, mode, NULL, 0,
|
|
ilen, input, output );
|
|
#endif
|
|
|
|
default:
|
|
return( MBEDTLS_ERR_RSA_INVALID_PADDING );
|
|
}
|
|
}
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function
|
|
*/
|
|
int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
const unsigned char *label, size_t label_len,
|
|
size_t *olen,
|
|
const unsigned char *input,
|
|
unsigned char *output,
|
|
size_t output_max_len )
|
|
{
|
|
int ret;
|
|
size_t ilen, i, pad_len;
|
|
unsigned char *p, bad, pad_done;
|
|
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
|
|
unsigned char lhash[MBEDTLS_MD_MAX_SIZE];
|
|
unsigned int hlen;
|
|
const mbedtls_md_info_t *md_info;
|
|
mbedtls_md_context_t md_ctx;
|
|
|
|
/*
|
|
* Parameters sanity checks
|
|
*/
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
ilen = ctx->len;
|
|
|
|
if( ilen < 16 || ilen > sizeof( buf ) )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
|
|
if( md_info == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
hlen = mbedtls_md_get_size( md_info );
|
|
|
|
// checking for integer underflow
|
|
if( 2 * hlen + 2 > ilen )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
/*
|
|
* RSA operation
|
|
*/
|
|
ret = ( mode == MBEDTLS_RSA_PUBLIC )
|
|
? mbedtls_rsa_public( ctx, input, buf )
|
|
: mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf );
|
|
|
|
if( ret != 0 )
|
|
goto cleanup;
|
|
|
|
/*
|
|
* Unmask data and generate lHash
|
|
*/
|
|
mbedtls_md_init( &md_ctx );
|
|
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
|
|
{
|
|
mbedtls_md_free( &md_ctx );
|
|
goto cleanup;
|
|
}
|
|
|
|
/* seed: Apply seedMask to maskedSeed */
|
|
if( ( ret = mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1,
|
|
&md_ctx ) ) != 0 ||
|
|
/* DB: Apply dbMask to maskedDB */
|
|
( ret = mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen,
|
|
&md_ctx ) ) != 0 )
|
|
{
|
|
mbedtls_md_free( &md_ctx );
|
|
goto cleanup;
|
|
}
|
|
|
|
mbedtls_md_free( &md_ctx );
|
|
|
|
/* Generate lHash */
|
|
if( ( ret = mbedtls_md( md_info, label, label_len, lhash ) ) != 0 )
|
|
goto cleanup;
|
|
|
|
/*
|
|
* Check contents, in "constant-time"
|
|
*/
|
|
p = buf;
|
|
bad = 0;
|
|
|
|
bad |= *p++; /* First byte must be 0 */
|
|
|
|
p += hlen; /* Skip seed */
|
|
|
|
/* Check lHash */
|
|
for( i = 0; i < hlen; i++ )
|
|
bad |= lhash[i] ^ *p++;
|
|
|
|
/* Get zero-padding len, but always read till end of buffer
|
|
* (minus one, for the 01 byte) */
|
|
pad_len = 0;
|
|
pad_done = 0;
|
|
for( i = 0; i < ilen - 2 * hlen - 2; i++ )
|
|
{
|
|
pad_done |= p[i];
|
|
pad_len += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
|
|
}
|
|
|
|
p += pad_len;
|
|
bad |= *p++ ^ 0x01;
|
|
|
|
/*
|
|
* The only information "leaked" is whether the padding was correct or not
|
|
* (eg, no data is copied if it was not correct). This meets the
|
|
* recommendations in PKCS#1 v2.2: an opponent cannot distinguish between
|
|
* the different error conditions.
|
|
*/
|
|
if( bad != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( ilen - ( p - buf ) > output_max_len )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE;
|
|
goto cleanup;
|
|
}
|
|
|
|
*olen = ilen - (p - buf);
|
|
memcpy( output, p, *olen );
|
|
ret = 0;
|
|
|
|
cleanup:
|
|
mbedtls_zeroize( buf, sizeof( buf ) );
|
|
mbedtls_zeroize( lhash, sizeof( lhash ) );
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V21 */
|
|
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
/** Turn zero-or-nonzero into zero-or-all-bits-one, without branches.
|
|
*
|
|
* \param value The value to analyze.
|
|
* \return Zero if \p value is zero, otherwise all-bits-one.
|
|
*/
|
|
static unsigned all_or_nothing_int( unsigned value )
|
|
{
|
|
/* MSVC has a warning about unary minus on unsigned, but this is
|
|
* well-defined and precisely what we want to do here */
|
|
#if defined(_MSC_VER)
|
|
#pragma warning( push )
|
|
#pragma warning( disable : 4146 )
|
|
#endif
|
|
return( - ( ( value | - value ) >> ( sizeof( value ) * 8 - 1 ) ) );
|
|
#if defined(_MSC_VER)
|
|
#pragma warning( pop )
|
|
#endif
|
|
}
|
|
|
|
/** Check whether a size is out of bounds, without branches.
|
|
*
|
|
* This is equivalent to `size > max`, but is likely to be compiled to
|
|
* to code using bitwise operation rather than a branch.
|
|
*
|
|
* \param size Size to check.
|
|
* \param max Maximum desired value for \p size.
|
|
* \return \c 0 if `size <= max`.
|
|
* \return \c 1 if `size > max`.
|
|
*/
|
|
static unsigned size_greater_than( size_t size, size_t max )
|
|
{
|
|
/* Return the sign bit (1 for negative) of (max - size). */
|
|
return( ( max - size ) >> ( sizeof( size_t ) * 8 - 1 ) );
|
|
}
|
|
|
|
/** Choose between two integer values, without branches.
|
|
*
|
|
* This is equivalent to `cond ? if1 : if0`, but is likely to be compiled
|
|
* to code using bitwise operation rather than a branch.
|
|
*
|
|
* \param cond Condition to test.
|
|
* \param if1 Value to use if \p cond is nonzero.
|
|
* \param if0 Value to use if \p cond is zero.
|
|
* \return \c if1 if \p cond is nonzero, otherwise \c if0.
|
|
*/
|
|
static unsigned if_int( unsigned cond, unsigned if1, unsigned if0 )
|
|
{
|
|
unsigned mask = all_or_nothing_int( cond );
|
|
return( ( mask & if1 ) | (~mask & if0 ) );
|
|
}
|
|
|
|
/** Shift some data towards the left inside a buffer without leaking
|
|
* the length of the data through side channels.
|
|
*
|
|
* `mem_move_to_left(start, total, offset)` is functionally equivalent to
|
|
* ```
|
|
* memmove(start, start + offset, total - offset);
|
|
* memset(start + offset, 0, total - offset);
|
|
* ```
|
|
* but it strives to use a memory access pattern (and thus total timing)
|
|
* that does not depend on \p offset. This timing independence comes at
|
|
* the expense of performance.
|
|
*
|
|
* \param start Pointer to the start of the buffer.
|
|
* \param total Total size of the buffer.
|
|
* \param offset Offset from which to copy \p total - \p offset bytes.
|
|
*/
|
|
static void mem_move_to_left( void *start,
|
|
size_t total,
|
|
size_t offset )
|
|
{
|
|
volatile unsigned char *buf = start;
|
|
size_t i, n;
|
|
if( total == 0 )
|
|
return;
|
|
for( i = 0; i < total; i++ )
|
|
{
|
|
unsigned no_op = size_greater_than( total - offset, i );
|
|
/* The first `total - offset` passes are a no-op. The last
|
|
* `offset` passes shift the data one byte to the left and
|
|
* zero out the last byte. */
|
|
for( n = 0; n < total - 1; n++ )
|
|
{
|
|
unsigned char current = buf[n];
|
|
unsigned char next = buf[n+1];
|
|
buf[n] = if_int( no_op, current, next );
|
|
}
|
|
buf[total-1] = if_int( no_op, buf[total-1], 0 );
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
|
|
*/
|
|
int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode, size_t *olen,
|
|
const unsigned char *input,
|
|
unsigned char *output,
|
|
size_t output_max_len )
|
|
{
|
|
int ret;
|
|
size_t ilen = ctx->len;
|
|
size_t i;
|
|
size_t plaintext_max_size = ( output_max_len > ilen - 11 ?
|
|
ilen - 11 :
|
|
output_max_len );
|
|
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
|
|
/* The following variables take sensitive values: their value must
|
|
* not leak into the observable behavior of the function other than
|
|
* the designated outputs (output, olen, return value). Otherwise
|
|
* this would open the execution of the function to
|
|
* side-channel-based variants of the Bleichenbacher padding oracle
|
|
* attack. Potential side channels include overall timing, memory
|
|
* access patterns (especially visible to an adversary who has access
|
|
* to a shared memory cache), and branches (especially visible to
|
|
* an adversary who has access to a shared code cache or to a shared
|
|
* branch predictor). */
|
|
size_t pad_count = 0;
|
|
unsigned bad = 0;
|
|
unsigned char pad_done = 0;
|
|
size_t plaintext_size = 0;
|
|
unsigned output_too_large;
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
if( ilen < 16 || ilen > sizeof( buf ) )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
ret = ( mode == MBEDTLS_RSA_PUBLIC )
|
|
? mbedtls_rsa_public( ctx, input, buf )
|
|
: mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf );
|
|
|
|
if( ret != 0 )
|
|
goto cleanup;
|
|
|
|
/* Check and get padding length in constant time and constant
|
|
* memory trace. The first byte must be 0. */
|
|
bad |= buf[0];
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE )
|
|
{
|
|
/* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00
|
|
* where PS must be at least 8 nonzero bytes. */
|
|
bad |= buf[1] ^ MBEDTLS_RSA_CRYPT;
|
|
|
|
/* Read the whole buffer. Set pad_done to nonzero if we find
|
|
* the 0x00 byte and remember the padding length in pad_count. */
|
|
for( i = 2; i < ilen; i++ )
|
|
{
|
|
pad_done |= ((buf[i] | (unsigned char)-buf[i]) >> 7) ^ 1;
|
|
pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Decode EMSA-PKCS1-v1_5 padding: 0x00 || 0x01 || PS || 0x00
|
|
* where PS must be at least 8 bytes with the value 0xFF. */
|
|
bad |= buf[1] ^ MBEDTLS_RSA_SIGN;
|
|
|
|
/* Read the whole buffer. Set pad_done to nonzero if we find
|
|
* the 0x00 byte and remember the padding length in pad_count.
|
|
* If there's a non-0xff byte in the padding, the padding is bad. */
|
|
for( i = 2; i < ilen; i++ )
|
|
{
|
|
pad_done |= if_int( buf[i], 0, 1 );
|
|
pad_count += if_int( pad_done, 0, 1 );
|
|
bad |= if_int( pad_done, 0, buf[i] ^ 0xFF );
|
|
}
|
|
}
|
|
|
|
/* If pad_done is still zero, there's no data, only unfinished padding. */
|
|
bad |= if_int( pad_done, 0, 1 );
|
|
|
|
/* There must be at least 8 bytes of padding. */
|
|
bad |= size_greater_than( 8, pad_count );
|
|
|
|
/* If the padding is valid, set plaintext_size to the number of
|
|
* remaining bytes after stripping the padding. If the padding
|
|
* is invalid, avoid leaking this fact through the size of the
|
|
* output: use the maximum message size that fits in the output
|
|
* buffer. Do it without branches to avoid leaking the padding
|
|
* validity through timing. RSA keys are small enough that all the
|
|
* size_t values involved fit in unsigned int. */
|
|
plaintext_size = if_int( bad,
|
|
(unsigned) plaintext_max_size,
|
|
(unsigned) ( ilen - pad_count - 3 ) );
|
|
|
|
/* Set output_too_large to 0 if the plaintext fits in the output
|
|
* buffer and to 1 otherwise. */
|
|
output_too_large = size_greater_than( plaintext_size,
|
|
plaintext_max_size );
|
|
|
|
/* Set ret without branches to avoid timing attacks. Return:
|
|
* - INVALID_PADDING if the padding is bad (bad != 0).
|
|
* - OUTPUT_TOO_LARGE if the padding is good but the decrypted
|
|
* plaintext does not fit in the output buffer.
|
|
* - 0 if the padding is correct. */
|
|
ret = - (int) if_int( bad, - MBEDTLS_ERR_RSA_INVALID_PADDING,
|
|
if_int( output_too_large, - MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE,
|
|
0 ) );
|
|
|
|
/* If the padding is bad or the plaintext is too large, zero the
|
|
* data that we're about to copy to the output buffer.
|
|
* We need to copy the same amount of data
|
|
* from the same buffer whether the padding is good or not to
|
|
* avoid leaking the padding validity through overall timing or
|
|
* through memory or cache access patterns. */
|
|
bad = all_or_nothing_int( bad | output_too_large );
|
|
for( i = 11; i < ilen; i++ )
|
|
buf[i] &= ~bad;
|
|
|
|
/* If the plaintext is too large, truncate it to the buffer size.
|
|
* Copy anyway to avoid revealing the length through timing, because
|
|
* revealing the length is as bad as revealing the padding validity
|
|
* for a Bleichenbacher attack. */
|
|
plaintext_size = if_int( output_too_large,
|
|
(unsigned) plaintext_max_size,
|
|
(unsigned) plaintext_size );
|
|
|
|
/* Move the plaintext to the leftmost position where it can start in
|
|
* the working buffer, i.e. make it start plaintext_max_size from
|
|
* the end of the buffer. Do this with a memory access trace that
|
|
* does not depend on the plaintext size. After this move, the
|
|
* starting location of the plaintext is no longer sensitive
|
|
* information. */
|
|
mem_move_to_left( buf + ilen - plaintext_max_size,
|
|
plaintext_max_size,
|
|
plaintext_max_size - plaintext_size );
|
|
|
|
/* Finally copy the decrypted plaintext plus trailing zeros
|
|
* into the output buffer. */
|
|
memcpy( output, buf + ilen - plaintext_max_size, plaintext_max_size );
|
|
|
|
/* Report the amount of data we copied to the output buffer. In case
|
|
* of errors (bad padding or output too large), the value of *olen
|
|
* when this function returns is not specified. Making it equivalent
|
|
* to the good case limits the risks of leaking the padding validity. */
|
|
*olen = plaintext_size;
|
|
|
|
cleanup:
|
|
mbedtls_zeroize( buf, sizeof( buf ) );
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V15 */
|
|
|
|
/*
|
|
* Do an RSA operation, then remove the message padding
|
|
*/
|
|
int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode, size_t *olen,
|
|
const unsigned char *input,
|
|
unsigned char *output,
|
|
size_t output_max_len)
|
|
{
|
|
switch( ctx->padding )
|
|
{
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
case MBEDTLS_RSA_PKCS_V15:
|
|
return mbedtls_rsa_rsaes_pkcs1_v15_decrypt( ctx, f_rng, p_rng, mode, olen,
|
|
input, output, output_max_len );
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
case MBEDTLS_RSA_PKCS_V21:
|
|
return mbedtls_rsa_rsaes_oaep_decrypt( ctx, f_rng, p_rng, mode, NULL, 0,
|
|
olen, input, output,
|
|
output_max_len );
|
|
#endif
|
|
|
|
default:
|
|
return( MBEDTLS_ERR_RSA_INVALID_PADDING );
|
|
}
|
|
}
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
|
|
*/
|
|
int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
unsigned char *sig )
|
|
{
|
|
size_t olen;
|
|
unsigned char *p = sig;
|
|
unsigned char salt[MBEDTLS_MD_MAX_SIZE];
|
|
unsigned int slen, hlen, offset = 0;
|
|
int ret;
|
|
size_t msb;
|
|
const mbedtls_md_info_t *md_info;
|
|
mbedtls_md_context_t md_ctx;
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
if( f_rng == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
olen = ctx->len;
|
|
|
|
if( md_alg != MBEDTLS_MD_NONE )
|
|
{
|
|
/* Gather length of hash to sign */
|
|
md_info = mbedtls_md_info_from_type( md_alg );
|
|
if( md_info == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
hashlen = mbedtls_md_get_size( md_info );
|
|
}
|
|
|
|
md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
|
|
if( md_info == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
hlen = mbedtls_md_get_size( md_info );
|
|
slen = hlen;
|
|
|
|
if( olen < hlen + slen + 2 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
memset( sig, 0, olen );
|
|
|
|
/* Generate salt of length slen */
|
|
if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
|
|
return( MBEDTLS_ERR_RSA_RNG_FAILED + ret );
|
|
|
|
/* Note: EMSA-PSS encoding is over the length of N - 1 bits */
|
|
msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
|
|
p += olen - hlen * 2 - 2;
|
|
*p++ = 0x01;
|
|
memcpy( p, salt, slen );
|
|
p += slen;
|
|
|
|
mbedtls_md_init( &md_ctx );
|
|
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
|
|
goto exit;
|
|
|
|
/* Generate H = Hash( M' ) */
|
|
if( ( ret = mbedtls_md_starts( &md_ctx ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = mbedtls_md_update( &md_ctx, p, 8 ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = mbedtls_md_update( &md_ctx, hash, hashlen ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = mbedtls_md_update( &md_ctx, salt, slen ) ) != 0 )
|
|
goto exit;
|
|
if( ( ret = mbedtls_md_finish( &md_ctx, p ) ) != 0 )
|
|
goto exit;
|
|
|
|
/* Compensate for boundary condition when applying mask */
|
|
if( msb % 8 == 0 )
|
|
offset = 1;
|
|
|
|
/* maskedDB: Apply dbMask to DB */
|
|
if( ( ret = mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen,
|
|
&md_ctx ) ) != 0 )
|
|
goto exit;
|
|
|
|
msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
|
|
sig[0] &= 0xFF >> ( olen * 8 - msb );
|
|
|
|
p += hlen;
|
|
*p++ = 0xBC;
|
|
|
|
mbedtls_zeroize( salt, sizeof( salt ) );
|
|
|
|
exit:
|
|
mbedtls_md_free( &md_ctx );
|
|
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
return( ( mode == MBEDTLS_RSA_PUBLIC )
|
|
? mbedtls_rsa_public( ctx, sig, sig )
|
|
: mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig ) );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V21 */
|
|
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function
|
|
*/
|
|
|
|
/* Construct a PKCS v1.5 encoding of a hashed message
|
|
*
|
|
* This is used both for signature generation and verification.
|
|
*
|
|
* Parameters:
|
|
* - md_alg: Identifies the hash algorithm used to generate the given hash;
|
|
* MBEDTLS_MD_NONE if raw data is signed.
|
|
* - hashlen: Length of hash in case hashlen is MBEDTLS_MD_NONE.
|
|
* - hash: Buffer containing the hashed message or the raw data.
|
|
* - dst_len: Length of the encoded message.
|
|
* - dst: Buffer to hold the encoded message.
|
|
*
|
|
* Assumptions:
|
|
* - hash has size hashlen if md_alg == MBEDTLS_MD_NONE.
|
|
* - hash has size corresponding to md_alg if md_alg != MBEDTLS_MD_NONE.
|
|
* - dst points to a buffer of size at least dst_len.
|
|
*
|
|
*/
|
|
static int rsa_rsassa_pkcs1_v15_encode( mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
size_t dst_len,
|
|
unsigned char *dst )
|
|
{
|
|
size_t oid_size = 0;
|
|
size_t nb_pad = dst_len;
|
|
unsigned char *p = dst;
|
|
const char *oid = NULL;
|
|
|
|
/* Are we signing hashed or raw data? */
|
|
if( md_alg != MBEDTLS_MD_NONE )
|
|
{
|
|
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg );
|
|
if( md_info == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
if( mbedtls_oid_get_oid_by_md( md_alg, &oid, &oid_size ) != 0 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
hashlen = mbedtls_md_get_size( md_info );
|
|
|
|
/* Double-check that 8 + hashlen + oid_size can be used as a
|
|
* 1-byte ASN.1 length encoding and that there's no overflow. */
|
|
if( 8 + hashlen + oid_size >= 0x80 ||
|
|
10 + hashlen < hashlen ||
|
|
10 + hashlen + oid_size < 10 + hashlen )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
/*
|
|
* Static bounds check:
|
|
* - Need 10 bytes for five tag-length pairs.
|
|
* (Insist on 1-byte length encodings to protect against variants of
|
|
* Bleichenbacher's forgery attack against lax PKCS#1v1.5 verification)
|
|
* - Need hashlen bytes for hash
|
|
* - Need oid_size bytes for hash alg OID.
|
|
*/
|
|
if( nb_pad < 10 + hashlen + oid_size )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
nb_pad -= 10 + hashlen + oid_size;
|
|
}
|
|
else
|
|
{
|
|
if( nb_pad < hashlen )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
nb_pad -= hashlen;
|
|
}
|
|
|
|
/* Need space for signature header and padding delimiter (3 bytes),
|
|
* and 8 bytes for the minimal padding */
|
|
if( nb_pad < 3 + 8 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
nb_pad -= 3;
|
|
|
|
/* Now nb_pad is the amount of memory to be filled
|
|
* with padding, and at least 8 bytes long. */
|
|
|
|
/* Write signature header and padding */
|
|
*p++ = 0;
|
|
*p++ = MBEDTLS_RSA_SIGN;
|
|
memset( p, 0xFF, nb_pad );
|
|
p += nb_pad;
|
|
*p++ = 0;
|
|
|
|
/* Are we signing raw data? */
|
|
if( md_alg == MBEDTLS_MD_NONE )
|
|
{
|
|
memcpy( p, hash, hashlen );
|
|
return( 0 );
|
|
}
|
|
|
|
/* Signing hashed data, add corresponding ASN.1 structure
|
|
*
|
|
* DigestInfo ::= SEQUENCE {
|
|
* digestAlgorithm DigestAlgorithmIdentifier,
|
|
* digest Digest }
|
|
* DigestAlgorithmIdentifier ::= AlgorithmIdentifier
|
|
* Digest ::= OCTET STRING
|
|
*
|
|
* Schematic:
|
|
* TAG-SEQ + LEN [ TAG-SEQ + LEN [ TAG-OID + LEN [ OID ]
|
|
* TAG-NULL + LEN [ NULL ] ]
|
|
* TAG-OCTET + LEN [ HASH ] ]
|
|
*/
|
|
*p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
|
|
*p++ = (unsigned char)( 0x08 + oid_size + hashlen );
|
|
*p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
|
|
*p++ = (unsigned char)( 0x04 + oid_size );
|
|
*p++ = MBEDTLS_ASN1_OID;
|
|
*p++ = (unsigned char) oid_size;
|
|
memcpy( p, oid, oid_size );
|
|
p += oid_size;
|
|
*p++ = MBEDTLS_ASN1_NULL;
|
|
*p++ = 0x00;
|
|
*p++ = MBEDTLS_ASN1_OCTET_STRING;
|
|
*p++ = (unsigned char) hashlen;
|
|
memcpy( p, hash, hashlen );
|
|
p += hashlen;
|
|
|
|
/* Just a sanity-check, should be automatic
|
|
* after the initial bounds check. */
|
|
if( p != dst + dst_len )
|
|
{
|
|
mbedtls_zeroize( dst, dst_len );
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Do an RSA operation to sign the message digest
|
|
*/
|
|
int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
unsigned char *sig )
|
|
{
|
|
int ret;
|
|
unsigned char *sig_try = NULL, *verif = NULL;
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
/*
|
|
* Prepare PKCS1-v1.5 encoding (padding and hash identifier)
|
|
*/
|
|
|
|
if( ( ret = rsa_rsassa_pkcs1_v15_encode( md_alg, hashlen, hash,
|
|
ctx->len, sig ) ) != 0 )
|
|
return( ret );
|
|
|
|
/*
|
|
* Call respective RSA primitive
|
|
*/
|
|
|
|
if( mode == MBEDTLS_RSA_PUBLIC )
|
|
{
|
|
/* Skip verification on a public key operation */
|
|
return( mbedtls_rsa_public( ctx, sig, sig ) );
|
|
}
|
|
|
|
/* Private key operation
|
|
*
|
|
* In order to prevent Lenstra's attack, make the signature in a
|
|
* temporary buffer and check it before returning it.
|
|
*/
|
|
|
|
sig_try = mbedtls_calloc( 1, ctx->len );
|
|
if( sig_try == NULL )
|
|
return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
|
|
|
|
verif = mbedtls_calloc( 1, ctx->len );
|
|
if( verif == NULL )
|
|
{
|
|
mbedtls_free( sig_try );
|
|
return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
|
|
}
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig_try ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_public( ctx, sig_try, verif ) );
|
|
|
|
if( mbedtls_safer_memcmp( verif, sig, ctx->len ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
|
|
goto cleanup;
|
|
}
|
|
|
|
memcpy( sig, sig_try, ctx->len );
|
|
|
|
cleanup:
|
|
mbedtls_free( sig_try );
|
|
mbedtls_free( verif );
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V15 */
|
|
|
|
/*
|
|
* Do an RSA operation to sign the message digest
|
|
*/
|
|
int mbedtls_rsa_pkcs1_sign( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
unsigned char *sig )
|
|
{
|
|
switch( ctx->padding )
|
|
{
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
case MBEDTLS_RSA_PKCS_V15:
|
|
return mbedtls_rsa_rsassa_pkcs1_v15_sign( ctx, f_rng, p_rng, mode, md_alg,
|
|
hashlen, hash, sig );
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
case MBEDTLS_RSA_PKCS_V21:
|
|
return mbedtls_rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg,
|
|
hashlen, hash, sig );
|
|
#endif
|
|
|
|
default:
|
|
return( MBEDTLS_ERR_RSA_INVALID_PADDING );
|
|
}
|
|
}
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function
|
|
*/
|
|
int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
mbedtls_md_type_t mgf1_hash_id,
|
|
int expected_salt_len,
|
|
const unsigned char *sig )
|
|
{
|
|
int ret;
|
|
size_t siglen;
|
|
unsigned char *p;
|
|
unsigned char *hash_start;
|
|
unsigned char result[MBEDTLS_MD_MAX_SIZE];
|
|
unsigned char zeros[8];
|
|
unsigned int hlen;
|
|
size_t observed_salt_len, msb;
|
|
const mbedtls_md_info_t *md_info;
|
|
mbedtls_md_context_t md_ctx;
|
|
unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
siglen = ctx->len;
|
|
|
|
if( siglen < 16 || siglen > sizeof( buf ) )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
ret = ( mode == MBEDTLS_RSA_PUBLIC )
|
|
? mbedtls_rsa_public( ctx, sig, buf )
|
|
: mbedtls_rsa_private( ctx, f_rng, p_rng, sig, buf );
|
|
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
p = buf;
|
|
|
|
if( buf[siglen - 1] != 0xBC )
|
|
return( MBEDTLS_ERR_RSA_INVALID_PADDING );
|
|
|
|
if( md_alg != MBEDTLS_MD_NONE )
|
|
{
|
|
/* Gather length of hash to sign */
|
|
md_info = mbedtls_md_info_from_type( md_alg );
|
|
if( md_info == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
hashlen = mbedtls_md_get_size( md_info );
|
|
}
|
|
|
|
md_info = mbedtls_md_info_from_type( mgf1_hash_id );
|
|
if( md_info == NULL )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
hlen = mbedtls_md_get_size( md_info );
|
|
|
|
memset( zeros, 0, 8 );
|
|
|
|
/*
|
|
* Note: EMSA-PSS verification is over the length of N - 1 bits
|
|
*/
|
|
msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
|
|
|
|
if( buf[0] >> ( 8 - siglen * 8 + msb ) )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
/* Compensate for boundary condition when applying mask */
|
|
if( msb % 8 == 0 )
|
|
{
|
|
p++;
|
|
siglen -= 1;
|
|
}
|
|
|
|
if( siglen < hlen + 2 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
hash_start = p + siglen - hlen - 1;
|
|
|
|
mbedtls_md_init( &md_ctx );
|
|
if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
|
|
goto exit;
|
|
|
|
ret = mgf_mask( p, siglen - hlen - 1, hash_start, hlen, &md_ctx );
|
|
if( ret != 0 )
|
|
goto exit;
|
|
|
|
buf[0] &= 0xFF >> ( siglen * 8 - msb );
|
|
|
|
while( p < hash_start - 1 && *p == 0 )
|
|
p++;
|
|
|
|
if( *p++ != 0x01 )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
|
|
goto exit;
|
|
}
|
|
|
|
observed_salt_len = hash_start - p;
|
|
|
|
if( expected_salt_len != MBEDTLS_RSA_SALT_LEN_ANY &&
|
|
observed_salt_len != (size_t) expected_salt_len )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
|
|
goto exit;
|
|
}
|
|
|
|
/*
|
|
* Generate H = Hash( M' )
|
|
*/
|
|
ret = mbedtls_md_starts( &md_ctx );
|
|
if ( ret != 0 )
|
|
goto exit;
|
|
ret = mbedtls_md_update( &md_ctx, zeros, 8 );
|
|
if ( ret != 0 )
|
|
goto exit;
|
|
ret = mbedtls_md_update( &md_ctx, hash, hashlen );
|
|
if ( ret != 0 )
|
|
goto exit;
|
|
ret = mbedtls_md_update( &md_ctx, p, observed_salt_len );
|
|
if ( ret != 0 )
|
|
goto exit;
|
|
ret = mbedtls_md_finish( &md_ctx, result );
|
|
if ( ret != 0 )
|
|
goto exit;
|
|
|
|
if( memcmp( hash_start, result, hlen ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
|
|
goto exit;
|
|
}
|
|
|
|
exit:
|
|
mbedtls_md_free( &md_ctx );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function
|
|
*/
|
|
int mbedtls_rsa_rsassa_pss_verify( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
const unsigned char *sig )
|
|
{
|
|
mbedtls_md_type_t mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE )
|
|
? (mbedtls_md_type_t) ctx->hash_id
|
|
: md_alg;
|
|
|
|
return( mbedtls_rsa_rsassa_pss_verify_ext( ctx, f_rng, p_rng, mode,
|
|
md_alg, hashlen, hash,
|
|
mgf1_hash_id, MBEDTLS_RSA_SALT_LEN_ANY,
|
|
sig ) );
|
|
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V21 */
|
|
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
/*
|
|
* Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function
|
|
*/
|
|
int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
const unsigned char *sig )
|
|
{
|
|
int ret = 0;
|
|
const size_t sig_len = ctx->len;
|
|
unsigned char *encoded = NULL, *encoded_expected = NULL;
|
|
|
|
if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
|
|
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
|
|
|
|
/*
|
|
* Prepare expected PKCS1 v1.5 encoding of hash.
|
|
*/
|
|
|
|
if( ( encoded = mbedtls_calloc( 1, sig_len ) ) == NULL ||
|
|
( encoded_expected = mbedtls_calloc( 1, sig_len ) ) == NULL )
|
|
{
|
|
ret = MBEDTLS_ERR_MPI_ALLOC_FAILED;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( ( ret = rsa_rsassa_pkcs1_v15_encode( md_alg, hashlen, hash, sig_len,
|
|
encoded_expected ) ) != 0 )
|
|
goto cleanup;
|
|
|
|
/*
|
|
* Apply RSA primitive to get what should be PKCS1 encoded hash.
|
|
*/
|
|
|
|
ret = ( mode == MBEDTLS_RSA_PUBLIC )
|
|
? mbedtls_rsa_public( ctx, sig, encoded )
|
|
: mbedtls_rsa_private( ctx, f_rng, p_rng, sig, encoded );
|
|
if( ret != 0 )
|
|
goto cleanup;
|
|
|
|
/*
|
|
* Compare
|
|
*/
|
|
|
|
if( ( ret = mbedtls_safer_memcmp( encoded, encoded_expected,
|
|
sig_len ) ) != 0 )
|
|
{
|
|
ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
|
|
goto cleanup;
|
|
}
|
|
|
|
cleanup:
|
|
|
|
if( encoded != NULL )
|
|
{
|
|
mbedtls_zeroize( encoded, sig_len );
|
|
mbedtls_free( encoded );
|
|
}
|
|
|
|
if( encoded_expected != NULL )
|
|
{
|
|
mbedtls_zeroize( encoded_expected, sig_len );
|
|
mbedtls_free( encoded_expected );
|
|
}
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V15 */
|
|
|
|
/*
|
|
* Do an RSA operation and check the message digest
|
|
*/
|
|
int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng,
|
|
int mode,
|
|
mbedtls_md_type_t md_alg,
|
|
unsigned int hashlen,
|
|
const unsigned char *hash,
|
|
const unsigned char *sig )
|
|
{
|
|
switch( ctx->padding )
|
|
{
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
case MBEDTLS_RSA_PKCS_V15:
|
|
return mbedtls_rsa_rsassa_pkcs1_v15_verify( ctx, f_rng, p_rng, mode, md_alg,
|
|
hashlen, hash, sig );
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PKCS1_V21)
|
|
case MBEDTLS_RSA_PKCS_V21:
|
|
return mbedtls_rsa_rsassa_pss_verify( ctx, f_rng, p_rng, mode, md_alg,
|
|
hashlen, hash, sig );
|
|
#endif
|
|
|
|
default:
|
|
return( MBEDTLS_ERR_RSA_INVALID_PADDING );
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy the components of an RSA key
|
|
*/
|
|
int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src )
|
|
{
|
|
int ret;
|
|
|
|
dst->ver = src->ver;
|
|
dst->len = src->len;
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->N, &src->N ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->E, &src->E ) );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->D, &src->D ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->P, &src->P ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Q, &src->Q ) );
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DP, &src->DP ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DQ, &src->DQ ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->QP, &src->QP ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RP, &src->RP ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RQ, &src->RQ ) );
|
|
#endif
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RN, &src->RN ) );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vi, &src->Vi ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vf, &src->Vf ) );
|
|
|
|
dst->padding = src->padding;
|
|
dst->hash_id = src->hash_id;
|
|
|
|
cleanup:
|
|
if( ret != 0 )
|
|
mbedtls_rsa_free( dst );
|
|
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Free the components of an RSA key
|
|
*/
|
|
void mbedtls_rsa_free( mbedtls_rsa_context *ctx )
|
|
{
|
|
mbedtls_mpi_free( &ctx->Vi ); mbedtls_mpi_free( &ctx->Vf );
|
|
mbedtls_mpi_free( &ctx->RN ); mbedtls_mpi_free( &ctx->D );
|
|
mbedtls_mpi_free( &ctx->Q ); mbedtls_mpi_free( &ctx->P );
|
|
mbedtls_mpi_free( &ctx->E ); mbedtls_mpi_free( &ctx->N );
|
|
|
|
#if !defined(MBEDTLS_RSA_NO_CRT)
|
|
mbedtls_mpi_free( &ctx->RQ ); mbedtls_mpi_free( &ctx->RP );
|
|
mbedtls_mpi_free( &ctx->QP ); mbedtls_mpi_free( &ctx->DQ );
|
|
mbedtls_mpi_free( &ctx->DP );
|
|
#endif /* MBEDTLS_RSA_NO_CRT */
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
mbedtls_mutex_free( &ctx->mutex );
|
|
#endif
|
|
}
|
|
|
|
#endif /* !MBEDTLS_RSA_ALT */
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
|
|
#include "mbedtls/sha1.h"
|
|
|
|
/*
|
|
* Example RSA-1024 keypair, for test purposes
|
|
*/
|
|
#define KEY_LEN 128
|
|
|
|
#define RSA_N "9292758453063D803DD603D5E777D788" \
|
|
"8ED1D5BF35786190FA2F23EBC0848AEA" \
|
|
"DDA92CA6C3D80B32C4D109BE0F36D6AE" \
|
|
"7130B9CED7ACDF54CFC7555AC14EEBAB" \
|
|
"93A89813FBF3C4F8066D2D800F7C38A8" \
|
|
"1AE31942917403FF4946B0A83D3D3E05" \
|
|
"EE57C6F5F5606FB5D4BC6CD34EE0801A" \
|
|
"5E94BB77B07507233A0BC7BAC8F90F79"
|
|
|
|
#define RSA_E "10001"
|
|
|
|
#define RSA_D "24BF6185468786FDD303083D25E64EFC" \
|
|
"66CA472BC44D253102F8B4A9D3BFA750" \
|
|
"91386C0077937FE33FA3252D28855837" \
|
|
"AE1B484A8A9A45F7EE8C0C634F99E8CD" \
|
|
"DF79C5CE07EE72C7F123142198164234" \
|
|
"CABB724CF78B8173B9F880FC86322407" \
|
|
"AF1FEDFDDE2BEB674CA15F3E81A1521E" \
|
|
"071513A1E85B5DFA031F21ECAE91A34D"
|
|
|
|
#define RSA_P "C36D0EB7FCD285223CFB5AABA5BDA3D8" \
|
|
"2C01CAD19EA484A87EA4377637E75500" \
|
|
"FCB2005C5C7DD6EC4AC023CDA285D796" \
|
|
"C3D9E75E1EFC42488BB4F1D13AC30A57"
|
|
|
|
#define RSA_Q "C000DF51A7C77AE8D7C7370C1FF55B69" \
|
|
"E211C2B9E5DB1ED0BF61D0D9899620F4" \
|
|
"910E4168387E3C30AA1E00C339A79508" \
|
|
"8452DD96A9A5EA5D9DCA68DA636032AF"
|
|
|
|
#define PT_LEN 24
|
|
#define RSA_PT "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \
|
|
"\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD"
|
|
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
static int myrand( void *rng_state, unsigned char *output, size_t len )
|
|
{
|
|
#if !defined(__OpenBSD__)
|
|
size_t i;
|
|
|
|
if( rng_state != NULL )
|
|
rng_state = NULL;
|
|
|
|
for( i = 0; i < len; ++i )
|
|
output[i] = rand();
|
|
#else
|
|
if( rng_state != NULL )
|
|
rng_state = NULL;
|
|
|
|
arc4random_buf( output, len );
|
|
#endif /* !OpenBSD */
|
|
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_PKCS1_V15 */
|
|
|
|
/*
|
|
* Checkup routine
|
|
*/
|
|
int mbedtls_rsa_self_test( int verbose )
|
|
{
|
|
int ret = 0;
|
|
#if defined(MBEDTLS_PKCS1_V15)
|
|
size_t len;
|
|
mbedtls_rsa_context rsa;
|
|
unsigned char rsa_plaintext[PT_LEN];
|
|
unsigned char rsa_decrypted[PT_LEN];
|
|
unsigned char rsa_ciphertext[KEY_LEN];
|
|
#if defined(MBEDTLS_SHA1_C)
|
|
unsigned char sha1sum[20];
|
|
#endif
|
|
|
|
mbedtls_mpi K;
|
|
|
|
mbedtls_mpi_init( &K );
|
|
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_N ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, &K, NULL, NULL, NULL, NULL ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_P ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, &K, NULL, NULL, NULL ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_Q ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, &K, NULL, NULL ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_D ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, NULL, &K, NULL ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_E ) );
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, NULL, NULL, &K ) );
|
|
|
|
MBEDTLS_MPI_CHK( mbedtls_rsa_complete( &rsa ) );
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( " RSA key validation: " );
|
|
|
|
if( mbedtls_rsa_check_pubkey( &rsa ) != 0 ||
|
|
mbedtls_rsa_check_privkey( &rsa ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n PKCS#1 encryption : " );
|
|
|
|
memcpy( rsa_plaintext, RSA_PT, PT_LEN );
|
|
|
|
if( mbedtls_rsa_pkcs1_encrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PUBLIC,
|
|
PT_LEN, rsa_plaintext,
|
|
rsa_ciphertext ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n PKCS#1 decryption : " );
|
|
|
|
if( mbedtls_rsa_pkcs1_decrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PRIVATE,
|
|
&len, rsa_ciphertext, rsa_decrypted,
|
|
sizeof(rsa_decrypted) ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( memcmp( rsa_decrypted, rsa_plaintext, len ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n" );
|
|
|
|
#if defined(MBEDTLS_SHA1_C)
|
|
if( verbose != 0 )
|
|
mbedtls_printf( " PKCS#1 data sign : " );
|
|
|
|
if( mbedtls_sha1_ret( rsa_plaintext, PT_LEN, sha1sum ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
return( 1 );
|
|
}
|
|
|
|
if( mbedtls_rsa_pkcs1_sign( &rsa, myrand, NULL,
|
|
MBEDTLS_RSA_PRIVATE, MBEDTLS_MD_SHA1, 0,
|
|
sha1sum, rsa_ciphertext ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n PKCS#1 sig. verify: " );
|
|
|
|
if( mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL,
|
|
MBEDTLS_RSA_PUBLIC, MBEDTLS_MD_SHA1, 0,
|
|
sha1sum, rsa_ciphertext ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n" );
|
|
#endif /* MBEDTLS_SHA1_C */
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "\n" );
|
|
|
|
cleanup:
|
|
mbedtls_mpi_free( &K );
|
|
mbedtls_rsa_free( &rsa );
|
|
#else /* MBEDTLS_PKCS1_V15 */
|
|
((void) verbose);
|
|
#endif /* MBEDTLS_PKCS1_V15 */
|
|
return( ret );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#endif /* MBEDTLS_RSA_C */
|