1664 lines
45 KiB
C
1664 lines
45 KiB
C
/*
|
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* The RSA public-key cryptosystem
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*
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* Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
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*
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* This file is part of mbed TLS (https://www.polarssl.org)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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/*
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* RSA was designed by Ron Rivest, Adi Shamir and Len Adleman.
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*
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* http://theory.lcs.mit.edu/~rivest/rsapaper.pdf
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* http://www.cacr.math.uwaterloo.ca/hac/about/chap8.pdf
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*/
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#if !defined(POLARSSL_CONFIG_FILE)
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#include "polarssl/config.h"
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#else
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#include POLARSSL_CONFIG_FILE
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#endif
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#if defined(POLARSSL_RSA_C)
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#include "polarssl/rsa.h"
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#include "polarssl/oid.h"
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#if defined(POLARSSL_PKCS1_V21)
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#include "polarssl/md.h"
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#endif
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#include <stdlib.h>
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#include <stdio.h>
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#if defined(POLARSSL_PLATFORM_C)
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#include "polarssl/platform.h"
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#else
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#define polarssl_printf printf
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#endif
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/*
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* Initialize an RSA context
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*/
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void rsa_init( rsa_context *ctx,
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int padding,
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int hash_id )
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{
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memset( ctx, 0, sizeof( rsa_context ) );
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rsa_set_padding( ctx, padding, hash_id );
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#if defined(POLARSSL_THREADING_C)
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polarssl_mutex_init( &ctx->mutex );
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#endif
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}
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/*
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* Set padding for an existing RSA context
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*/
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void rsa_set_padding( rsa_context *ctx, int padding, int hash_id )
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{
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ctx->padding = padding;
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ctx->hash_id = hash_id;
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}
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#if defined(POLARSSL_GENPRIME)
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/*
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* Generate an RSA keypair
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*/
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int rsa_gen_key( rsa_context *ctx,
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int (*f_rng)(void *, unsigned char *, size_t),
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void *p_rng,
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unsigned int nbits, int exponent )
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{
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int ret;
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mpi P1, Q1, H, G;
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if( f_rng == NULL || nbits < 128 || exponent < 3 )
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return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
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mpi_init( &P1 ); mpi_init( &Q1 ); mpi_init( &H ); mpi_init( &G );
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/*
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* find primes P and Q with Q < P so that:
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* GCD( E, (P-1)*(Q-1) ) == 1
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*/
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MPI_CHK( mpi_lset( &ctx->E, exponent ) );
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do
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{
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MPI_CHK( mpi_gen_prime( &ctx->P, ( nbits + 1 ) >> 1, 0,
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f_rng, p_rng ) );
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MPI_CHK( mpi_gen_prime( &ctx->Q, ( nbits + 1 ) >> 1, 0,
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f_rng, p_rng ) );
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if( mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 )
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mpi_swap( &ctx->P, &ctx->Q );
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if( mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 )
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continue;
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MPI_CHK( mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
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if( mpi_msb( &ctx->N ) != nbits )
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continue;
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MPI_CHK( mpi_sub_int( &P1, &ctx->P, 1 ) );
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MPI_CHK( mpi_sub_int( &Q1, &ctx->Q, 1 ) );
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MPI_CHK( mpi_mul_mpi( &H, &P1, &Q1 ) );
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MPI_CHK( mpi_gcd( &G, &ctx->E, &H ) );
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}
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while( mpi_cmp_int( &G, 1 ) != 0 );
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/*
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* D = E^-1 mod ((P-1)*(Q-1))
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* DP = D mod (P - 1)
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* DQ = D mod (Q - 1)
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* QP = Q^-1 mod P
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*/
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MPI_CHK( mpi_inv_mod( &ctx->D , &ctx->E, &H ) );
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MPI_CHK( mpi_mod_mpi( &ctx->DP, &ctx->D, &P1 ) );
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MPI_CHK( mpi_mod_mpi( &ctx->DQ, &ctx->D, &Q1 ) );
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MPI_CHK( mpi_inv_mod( &ctx->QP, &ctx->Q, &ctx->P ) );
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ctx->len = ( mpi_msb( &ctx->N ) + 7 ) >> 3;
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cleanup:
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mpi_free( &P1 ); mpi_free( &Q1 ); mpi_free( &H ); mpi_free( &G );
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if( ret != 0 )
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{
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rsa_free( ctx );
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return( POLARSSL_ERR_RSA_KEY_GEN_FAILED + ret );
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}
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return( 0 );
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}
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#endif /* POLARSSL_GENPRIME */
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/*
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* Check a public RSA key
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*/
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int rsa_check_pubkey( const rsa_context *ctx )
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{
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if( !ctx->N.p || !ctx->E.p )
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
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if( ( ctx->N.p[0] & 1 ) == 0 ||
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( ctx->E.p[0] & 1 ) == 0 )
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
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if( mpi_msb( &ctx->N ) < 128 ||
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mpi_msb( &ctx->N ) > POLARSSL_MPI_MAX_BITS )
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
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if( mpi_msb( &ctx->E ) < 2 ||
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mpi_cmp_mpi( &ctx->E, &ctx->N ) >= 0 )
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
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return( 0 );
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}
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/*
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* Check a private RSA key
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*/
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int rsa_check_privkey( const rsa_context *ctx )
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{
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int ret;
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mpi PQ, DE, P1, Q1, H, I, G, G2, L1, L2, DP, DQ, QP;
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if( ( ret = rsa_check_pubkey( ctx ) ) != 0 )
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return( ret );
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if( !ctx->P.p || !ctx->Q.p || !ctx->D.p )
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
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mpi_init( &PQ ); mpi_init( &DE ); mpi_init( &P1 ); mpi_init( &Q1 );
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mpi_init( &H ); mpi_init( &I ); mpi_init( &G ); mpi_init( &G2 );
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mpi_init( &L1 ); mpi_init( &L2 ); mpi_init( &DP ); mpi_init( &DQ );
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mpi_init( &QP );
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MPI_CHK( mpi_mul_mpi( &PQ, &ctx->P, &ctx->Q ) );
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MPI_CHK( mpi_mul_mpi( &DE, &ctx->D, &ctx->E ) );
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MPI_CHK( mpi_sub_int( &P1, &ctx->P, 1 ) );
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MPI_CHK( mpi_sub_int( &Q1, &ctx->Q, 1 ) );
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MPI_CHK( mpi_mul_mpi( &H, &P1, &Q1 ) );
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MPI_CHK( mpi_gcd( &G, &ctx->E, &H ) );
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MPI_CHK( mpi_gcd( &G2, &P1, &Q1 ) );
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MPI_CHK( mpi_div_mpi( &L1, &L2, &H, &G2 ) );
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MPI_CHK( mpi_mod_mpi( &I, &DE, &L1 ) );
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MPI_CHK( mpi_mod_mpi( &DP, &ctx->D, &P1 ) );
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MPI_CHK( mpi_mod_mpi( &DQ, &ctx->D, &Q1 ) );
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MPI_CHK( mpi_inv_mod( &QP, &ctx->Q, &ctx->P ) );
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/*
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* Check for a valid PKCS1v2 private key
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*/
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if( mpi_cmp_mpi( &PQ, &ctx->N ) != 0 ||
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mpi_cmp_mpi( &DP, &ctx->DP ) != 0 ||
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mpi_cmp_mpi( &DQ, &ctx->DQ ) != 0 ||
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mpi_cmp_mpi( &QP, &ctx->QP ) != 0 ||
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mpi_cmp_int( &L2, 0 ) != 0 ||
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mpi_cmp_int( &I, 1 ) != 0 ||
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mpi_cmp_int( &G, 1 ) != 0 )
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{
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ret = POLARSSL_ERR_RSA_KEY_CHECK_FAILED;
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}
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cleanup:
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mpi_free( &PQ ); mpi_free( &DE ); mpi_free( &P1 ); mpi_free( &Q1 );
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mpi_free( &H ); mpi_free( &I ); mpi_free( &G ); mpi_free( &G2 );
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mpi_free( &L1 ); mpi_free( &L2 ); mpi_free( &DP ); mpi_free( &DQ );
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mpi_free( &QP );
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if( ret == POLARSSL_ERR_RSA_KEY_CHECK_FAILED )
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return( ret );
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if( ret != 0 )
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED + ret );
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return( 0 );
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}
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/*
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* Check if contexts holding a public and private key match
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*/
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int rsa_check_pub_priv( const rsa_context *pub, const rsa_context *prv )
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{
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if( rsa_check_pubkey( pub ) != 0 ||
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rsa_check_privkey( prv ) != 0 )
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{
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
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}
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|
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if( mpi_cmp_mpi( &pub->N, &prv->N ) != 0 ||
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mpi_cmp_mpi( &pub->E, &prv->E ) != 0 )
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{
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return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
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}
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return( 0 );
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}
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/*
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* Do an RSA public key operation
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*/
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int rsa_public( rsa_context *ctx,
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const unsigned char *input,
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unsigned char *output )
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{
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int ret;
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size_t olen;
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mpi T;
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mpi_init( &T );
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MPI_CHK( mpi_read_binary( &T, input, ctx->len ) );
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if( mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
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{
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mpi_free( &T );
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return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
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}
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olen = ctx->len;
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MPI_CHK( mpi_exp_mod( &T, &T, &ctx->E, &ctx->N, &ctx->RN ) );
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MPI_CHK( mpi_write_binary( &T, output, olen ) );
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cleanup:
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mpi_free( &T );
|
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if( ret != 0 )
|
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return( POLARSSL_ERR_RSA_PUBLIC_FAILED + ret );
|
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|
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return( 0 );
|
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}
|
||
|
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/*
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* Generate or update blinding values, see section 10 of:
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* KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
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* DSS, and other systems. In : Advances in Cryptology—CRYPTO’96. Springer
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* Berlin Heidelberg, 1996. p. 104-113.
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*/
|
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static int rsa_prepare_blinding( rsa_context *ctx, mpi *Vi, mpi *Vf,
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int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
|
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{
|
||
int ret, count = 0;
|
||
|
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#if defined(POLARSSL_THREADING_C)
|
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polarssl_mutex_lock( &ctx->mutex );
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#endif
|
||
|
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if( ctx->Vf.p != NULL )
|
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{
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/* We already have blinding values, just update them by squaring */
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MPI_CHK( mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
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MPI_CHK( mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
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MPI_CHK( mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
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MPI_CHK( mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->N ) );
|
||
|
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goto done;
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}
|
||
|
||
/* Unblinding value: Vf = random number, invertible mod N */
|
||
do {
|
||
if( count++ > 10 )
|
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return( POLARSSL_ERR_RSA_RNG_FAILED );
|
||
|
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MPI_CHK( mpi_fill_random( &ctx->Vf, ctx->len - 1, f_rng, p_rng ) );
|
||
MPI_CHK( mpi_gcd( &ctx->Vi, &ctx->Vf, &ctx->N ) );
|
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} while( mpi_cmp_int( &ctx->Vi, 1 ) != 0 );
|
||
|
||
/* Blinding value: Vi = Vf^(-e) mod N */
|
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MPI_CHK( mpi_inv_mod( &ctx->Vi, &ctx->Vf, &ctx->N ) );
|
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MPI_CHK( mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) );
|
||
|
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done:
|
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if( Vi != &ctx->Vi )
|
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{
|
||
MPI_CHK( mpi_copy( Vi, &ctx->Vi ) );
|
||
MPI_CHK( mpi_copy( Vf, &ctx->Vf ) );
|
||
}
|
||
|
||
cleanup:
|
||
#if defined(POLARSSL_THREADING_C)
|
||
polarssl_mutex_unlock( &ctx->mutex );
|
||
#endif
|
||
|
||
return( ret );
|
||
}
|
||
|
||
/*
|
||
* Do an RSA private key operation
|
||
*/
|
||
int rsa_private( rsa_context *ctx,
|
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int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
const unsigned char *input,
|
||
unsigned char *output )
|
||
{
|
||
int ret;
|
||
size_t olen;
|
||
mpi T, T1, T2;
|
||
mpi *Vi, *Vf;
|
||
|
||
/*
|
||
* When using the Chinese Remainder Theorem, we use blinding values.
|
||
* Without threading, we just read them directly from the context,
|
||
* otherwise we make a local copy in order to reduce locking contention.
|
||
*/
|
||
#if defined(POLARSSL_THREADING_C)
|
||
mpi Vi_copy, Vf_copy;
|
||
|
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mpi_init( &Vi_copy ); mpi_init( &Vf_copy );
|
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Vi = &Vi_copy;
|
||
Vf = &Vf_copy;
|
||
#else
|
||
Vi = &ctx->Vi;
|
||
Vf = &ctx->Vf;
|
||
#endif
|
||
|
||
mpi_init( &T ); mpi_init( &T1 ); mpi_init( &T2 );
|
||
|
||
MPI_CHK( mpi_read_binary( &T, input, ctx->len ) );
|
||
if( mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
|
||
{
|
||
mpi_free( &T );
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
}
|
||
|
||
if( f_rng != NULL )
|
||
{
|
||
/*
|
||
* Blinding
|
||
* T = T * Vi mod N
|
||
*/
|
||
MPI_CHK( rsa_prepare_blinding( ctx, Vi, Vf, f_rng, p_rng ) );
|
||
MPI_CHK( mpi_mul_mpi( &T, &T, Vi ) );
|
||
MPI_CHK( mpi_mod_mpi( &T, &T, &ctx->N ) );
|
||
}
|
||
|
||
#if defined(POLARSSL_RSA_NO_CRT)
|
||
MPI_CHK( mpi_exp_mod( &T, &T, &ctx->D, &ctx->N, &ctx->RN ) );
|
||
#else
|
||
/*
|
||
* faster decryption using the CRT
|
||
*
|
||
* T1 = input ^ dP mod P
|
||
* T2 = input ^ dQ mod Q
|
||
*/
|
||
MPI_CHK( mpi_exp_mod( &T1, &T, &ctx->DP, &ctx->P, &ctx->RP ) );
|
||
MPI_CHK( mpi_exp_mod( &T2, &T, &ctx->DQ, &ctx->Q, &ctx->RQ ) );
|
||
|
||
/*
|
||
* T = (T1 - T2) * (Q^-1 mod P) mod P
|
||
*/
|
||
MPI_CHK( mpi_sub_mpi( &T, &T1, &T2 ) );
|
||
MPI_CHK( mpi_mul_mpi( &T1, &T, &ctx->QP ) );
|
||
MPI_CHK( mpi_mod_mpi( &T, &T1, &ctx->P ) );
|
||
|
||
/*
|
||
* T = T2 + T * Q
|
||
*/
|
||
MPI_CHK( mpi_mul_mpi( &T1, &T, &ctx->Q ) );
|
||
MPI_CHK( mpi_add_mpi( &T, &T2, &T1 ) );
|
||
#endif /* POLARSSL_RSA_NO_CRT */
|
||
|
||
if( f_rng != NULL )
|
||
{
|
||
/*
|
||
* Unblind
|
||
* T = T * Vf mod N
|
||
*/
|
||
MPI_CHK( mpi_mul_mpi( &T, &T, Vf ) );
|
||
MPI_CHK( mpi_mod_mpi( &T, &T, &ctx->N ) );
|
||
}
|
||
|
||
olen = ctx->len;
|
||
MPI_CHK( mpi_write_binary( &T, output, olen ) );
|
||
|
||
cleanup:
|
||
mpi_free( &T ); mpi_free( &T1 ); mpi_free( &T2 );
|
||
#if defined(POLARSSL_THREADING_C)
|
||
mpi_free( &Vi_copy ); mpi_free( &Vf_copy );
|
||
#endif
|
||
|
||
if( ret != 0 )
|
||
return( POLARSSL_ERR_RSA_PRIVATE_FAILED + ret );
|
||
|
||
return( 0 );
|
||
}
|
||
|
||
#if defined(POLARSSL_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 void mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src,
|
||
size_t slen, md_context_t *md_ctx )
|
||
{
|
||
unsigned char mask[POLARSSL_MD_MAX_SIZE];
|
||
unsigned char counter[4];
|
||
unsigned char *p;
|
||
unsigned int hlen;
|
||
size_t i, use_len;
|
||
|
||
memset( mask, 0, POLARSSL_MD_MAX_SIZE );
|
||
memset( counter, 0, 4 );
|
||
|
||
hlen = md_ctx->md_info->size;
|
||
|
||
// Generate and apply dbMask
|
||
//
|
||
p = dst;
|
||
|
||
while( dlen > 0 )
|
||
{
|
||
use_len = hlen;
|
||
if( dlen < hlen )
|
||
use_len = dlen;
|
||
|
||
md_starts( md_ctx );
|
||
md_update( md_ctx, src, slen );
|
||
md_update( md_ctx, counter, 4 );
|
||
md_finish( md_ctx, mask );
|
||
|
||
for( i = 0; i < use_len; ++i )
|
||
*p++ ^= mask[i];
|
||
|
||
counter[3]++;
|
||
|
||
dlen -= use_len;
|
||
}
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V21 */
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function
|
||
*/
|
||
int rsa_rsaes_oaep_encrypt( 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 md_info_t *md_info;
|
||
md_context_t md_ctx;
|
||
|
||
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
if( f_rng == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
md_info = md_info_from_type( ctx->hash_id );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
olen = ctx->len;
|
||
hlen = md_get_size( md_info );
|
||
|
||
if( olen < ilen + 2 * hlen + 2 )
|
||
return( POLARSSL_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( POLARSSL_ERR_RSA_RNG_FAILED + ret );
|
||
|
||
p += hlen;
|
||
|
||
// Construct DB
|
||
//
|
||
md( md_info, label, label_len, p );
|
||
p += hlen;
|
||
p += olen - 2 * hlen - 2 - ilen;
|
||
*p++ = 1;
|
||
memcpy( p, input, ilen );
|
||
|
||
md_init( &md_ctx );
|
||
md_init_ctx( &md_ctx, md_info );
|
||
|
||
// maskedDB: Apply dbMask to DB
|
||
//
|
||
mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen,
|
||
&md_ctx );
|
||
|
||
// maskedSeed: Apply seedMask to seed
|
||
//
|
||
mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1,
|
||
&md_ctx );
|
||
|
||
md_free( &md_ctx );
|
||
|
||
return( ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, output, output )
|
||
: rsa_private( ctx, f_rng, p_rng, output, output ) );
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V21 */
|
||
|
||
#if defined(POLARSSL_PKCS1_V15)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function
|
||
*/
|
||
int rsa_rsaes_pkcs1_v15_encrypt( 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 == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
if( f_rng == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
olen = ctx->len;
|
||
|
||
if( olen < ilen + 11 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
nb_pad = olen - 3 - ilen;
|
||
|
||
*p++ = 0;
|
||
if( mode == RSA_PUBLIC )
|
||
{
|
||
*p++ = 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( POLARSSL_ERR_RSA_RNG_FAILED + ret );
|
||
|
||
p++;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
*p++ = RSA_SIGN;
|
||
|
||
while( nb_pad-- > 0 )
|
||
*p++ = 0xFF;
|
||
}
|
||
|
||
*p++ = 0;
|
||
memcpy( p, input, ilen );
|
||
|
||
return( ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, output, output )
|
||
: rsa_private( ctx, f_rng, p_rng, output, output ) );
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V15 */
|
||
|
||
/*
|
||
* Add the message padding, then do an RSA operation
|
||
*/
|
||
int rsa_pkcs1_encrypt( 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(POLARSSL_PKCS1_V15)
|
||
case RSA_PKCS_V15:
|
||
return rsa_rsaes_pkcs1_v15_encrypt( ctx, f_rng, p_rng, mode, ilen,
|
||
input, output );
|
||
#endif
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
case RSA_PKCS_V21:
|
||
return rsa_rsaes_oaep_encrypt( ctx, f_rng, p_rng, mode, NULL, 0,
|
||
ilen, input, output );
|
||
#endif
|
||
|
||
default:
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
}
|
||
}
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function
|
||
*/
|
||
int rsa_rsaes_oaep_decrypt( 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[POLARSSL_MPI_MAX_SIZE];
|
||
unsigned char lhash[POLARSSL_MD_MAX_SIZE];
|
||
unsigned int hlen;
|
||
const md_info_t *md_info;
|
||
md_context_t md_ctx;
|
||
|
||
/*
|
||
* Parameters sanity checks
|
||
*/
|
||
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
ilen = ctx->len;
|
||
|
||
if( ilen < 16 || ilen > sizeof( buf ) )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
md_info = md_info_from_type( ctx->hash_id );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
/*
|
||
* RSA operation
|
||
*/
|
||
ret = ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, input, buf )
|
||
: rsa_private( ctx, f_rng, p_rng, input, buf );
|
||
|
||
if( ret != 0 )
|
||
return( ret );
|
||
|
||
/*
|
||
* Unmask data and generate lHash
|
||
*/
|
||
hlen = md_get_size( md_info );
|
||
|
||
md_init( &md_ctx );
|
||
md_init_ctx( &md_ctx, md_info );
|
||
|
||
/* Generate lHash */
|
||
md( md_info, label, label_len, lhash );
|
||
|
||
/* seed: Apply seedMask to maskedSeed */
|
||
mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1,
|
||
&md_ctx );
|
||
|
||
/* DB: Apply dbMask to maskedDB */
|
||
mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen,
|
||
&md_ctx );
|
||
|
||
md_free( &md_ctx );
|
||
|
||
/*
|
||
* 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 == 0 );
|
||
}
|
||
|
||
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 )
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
|
||
if( ilen - ( p - buf ) > output_max_len )
|
||
return( POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE );
|
||
|
||
*olen = ilen - (p - buf);
|
||
memcpy( output, p, *olen );
|
||
|
||
return( 0 );
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V21 */
|
||
|
||
#if defined(POLARSSL_PKCS1_V15)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
|
||
*/
|
||
int rsa_rsaes_pkcs1_v15_decrypt( 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, pad_count = 0, i;
|
||
unsigned char *p, bad, pad_done = 0;
|
||
unsigned char buf[POLARSSL_MPI_MAX_SIZE];
|
||
|
||
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
ilen = ctx->len;
|
||
|
||
if( ilen < 16 || ilen > sizeof( buf ) )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
ret = ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, input, buf )
|
||
: rsa_private( ctx, f_rng, p_rng, input, buf );
|
||
|
||
if( ret != 0 )
|
||
return( ret );
|
||
|
||
p = buf;
|
||
bad = 0;
|
||
|
||
/*
|
||
* Check and get padding len in "constant-time"
|
||
*/
|
||
bad |= *p++; /* First byte must be 0 */
|
||
|
||
/* This test does not depend on secret data */
|
||
if( mode == RSA_PRIVATE )
|
||
{
|
||
bad |= *p++ ^ RSA_CRYPT;
|
||
|
||
/* Get padding len, but always read till end of buffer
|
||
* (minus one, for the 00 byte) */
|
||
for( i = 0; i < ilen - 3; i++ )
|
||
{
|
||
pad_done |= ( p[i] == 0 );
|
||
pad_count += ( pad_done == 0 );
|
||
}
|
||
|
||
p += pad_count;
|
||
bad |= *p++; /* Must be zero */
|
||
}
|
||
else
|
||
{
|
||
bad |= *p++ ^ RSA_SIGN;
|
||
|
||
/* Get padding len, but always read till end of buffer
|
||
* (minus one, for the 00 byte) */
|
||
for( i = 0; i < ilen - 3; i++ )
|
||
{
|
||
pad_done |= ( p[i] != 0xFF );
|
||
pad_count += ( pad_done == 0 );
|
||
}
|
||
|
||
p += pad_count;
|
||
bad |= *p++; /* Must be zero */
|
||
}
|
||
|
||
if( bad )
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
|
||
if( ilen - ( p - buf ) > output_max_len )
|
||
return( POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE );
|
||
|
||
*olen = ilen - (p - buf);
|
||
memcpy( output, p, *olen );
|
||
|
||
return( 0 );
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V15 */
|
||
|
||
/*
|
||
* Do an RSA operation, then remove the message padding
|
||
*/
|
||
int rsa_pkcs1_decrypt( 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(POLARSSL_PKCS1_V15)
|
||
case RSA_PKCS_V15:
|
||
return rsa_rsaes_pkcs1_v15_decrypt( ctx, f_rng, p_rng, mode, olen,
|
||
input, output, output_max_len );
|
||
#endif
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
case RSA_PKCS_V21:
|
||
return rsa_rsaes_oaep_decrypt( ctx, f_rng, p_rng, mode, NULL, 0,
|
||
olen, input, output,
|
||
output_max_len );
|
||
#endif
|
||
|
||
default:
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
}
|
||
}
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
|
||
*/
|
||
int rsa_rsassa_pss_sign( rsa_context *ctx,
|
||
int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
int mode,
|
||
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[POLARSSL_MD_MAX_SIZE];
|
||
unsigned int slen, hlen, offset = 0;
|
||
int ret;
|
||
size_t msb;
|
||
const md_info_t *md_info;
|
||
md_context_t md_ctx;
|
||
|
||
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
if( f_rng == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
olen = ctx->len;
|
||
|
||
if( md_alg != POLARSSL_MD_NONE )
|
||
{
|
||
// Gather length of hash to sign
|
||
//
|
||
md_info = md_info_from_type( md_alg );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
hashlen = md_get_size( md_info );
|
||
}
|
||
|
||
md_info = md_info_from_type( ctx->hash_id );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
hlen = md_get_size( md_info );
|
||
slen = hlen;
|
||
|
||
if( olen < hlen + slen + 2 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
memset( sig, 0, olen );
|
||
|
||
// Generate salt of length slen
|
||
//
|
||
if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
|
||
return( POLARSSL_ERR_RSA_RNG_FAILED + ret );
|
||
|
||
// Note: EMSA-PSS encoding is over the length of N - 1 bits
|
||
//
|
||
msb = mpi_msb( &ctx->N ) - 1;
|
||
p += olen - hlen * 2 - 2;
|
||
*p++ = 0x01;
|
||
memcpy( p, salt, slen );
|
||
p += slen;
|
||
|
||
md_init( &md_ctx );
|
||
md_init_ctx( &md_ctx, md_info );
|
||
|
||
// Generate H = Hash( M' )
|
||
//
|
||
md_starts( &md_ctx );
|
||
md_update( &md_ctx, p, 8 );
|
||
md_update( &md_ctx, hash, hashlen );
|
||
md_update( &md_ctx, salt, slen );
|
||
md_finish( &md_ctx, p );
|
||
|
||
// Compensate for boundary condition when applying mask
|
||
//
|
||
if( msb % 8 == 0 )
|
||
offset = 1;
|
||
|
||
// maskedDB: Apply dbMask to DB
|
||
//
|
||
mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen, &md_ctx );
|
||
|
||
md_free( &md_ctx );
|
||
|
||
msb = mpi_msb( &ctx->N ) - 1;
|
||
sig[0] &= 0xFF >> ( olen * 8 - msb );
|
||
|
||
p += hlen;
|
||
*p++ = 0xBC;
|
||
|
||
return( ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, sig, sig )
|
||
: rsa_private( ctx, f_rng, p_rng, sig, sig ) );
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V21 */
|
||
|
||
#if defined(POLARSSL_PKCS1_V15)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function
|
||
*/
|
||
/*
|
||
* Do an RSA operation to sign the message digest
|
||
*/
|
||
int rsa_rsassa_pkcs1_v15_sign( rsa_context *ctx,
|
||
int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
int mode,
|
||
md_type_t md_alg,
|
||
unsigned int hashlen,
|
||
const unsigned char *hash,
|
||
unsigned char *sig )
|
||
{
|
||
size_t nb_pad, olen, oid_size = 0;
|
||
unsigned char *p = sig;
|
||
const char *oid = NULL;
|
||
|
||
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
olen = ctx->len;
|
||
nb_pad = olen - 3;
|
||
|
||
if( md_alg != POLARSSL_MD_NONE )
|
||
{
|
||
const md_info_t *md_info = md_info_from_type( md_alg );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
if( oid_get_oid_by_md( md_alg, &oid, &oid_size ) != 0 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
nb_pad -= 10 + oid_size;
|
||
|
||
hashlen = md_get_size( md_info );
|
||
}
|
||
|
||
nb_pad -= hashlen;
|
||
|
||
if( ( nb_pad < 8 ) || ( nb_pad > olen ) )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
*p++ = 0;
|
||
*p++ = RSA_SIGN;
|
||
memset( p, 0xFF, nb_pad );
|
||
p += nb_pad;
|
||
*p++ = 0;
|
||
|
||
if( md_alg == POLARSSL_MD_NONE )
|
||
{
|
||
memcpy( p, hash, hashlen );
|
||
}
|
||
else
|
||
{
|
||
/*
|
||
* DigestInfo ::= SEQUENCE {
|
||
* digestAlgorithm DigestAlgorithmIdentifier,
|
||
* digest Digest }
|
||
*
|
||
* DigestAlgorithmIdentifier ::= AlgorithmIdentifier
|
||
*
|
||
* Digest ::= OCTET STRING
|
||
*/
|
||
*p++ = ASN1_SEQUENCE | ASN1_CONSTRUCTED;
|
||
*p++ = (unsigned char) ( 0x08 + oid_size + hashlen );
|
||
*p++ = ASN1_SEQUENCE | ASN1_CONSTRUCTED;
|
||
*p++ = (unsigned char) ( 0x04 + oid_size );
|
||
*p++ = ASN1_OID;
|
||
*p++ = oid_size & 0xFF;
|
||
memcpy( p, oid, oid_size );
|
||
p += oid_size;
|
||
*p++ = ASN1_NULL;
|
||
*p++ = 0x00;
|
||
*p++ = ASN1_OCTET_STRING;
|
||
*p++ = hashlen;
|
||
memcpy( p, hash, hashlen );
|
||
}
|
||
|
||
return( ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, sig, sig )
|
||
: rsa_private( ctx, f_rng, p_rng, sig, sig ) );
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V15 */
|
||
|
||
/*
|
||
* Do an RSA operation to sign the message digest
|
||
*/
|
||
int rsa_pkcs1_sign( rsa_context *ctx,
|
||
int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
int mode,
|
||
md_type_t md_alg,
|
||
unsigned int hashlen,
|
||
const unsigned char *hash,
|
||
unsigned char *sig )
|
||
{
|
||
switch( ctx->padding )
|
||
{
|
||
#if defined(POLARSSL_PKCS1_V15)
|
||
case RSA_PKCS_V15:
|
||
return rsa_rsassa_pkcs1_v15_sign( ctx, f_rng, p_rng, mode, md_alg,
|
||
hashlen, hash, sig );
|
||
#endif
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
case RSA_PKCS_V21:
|
||
return rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg,
|
||
hashlen, hash, sig );
|
||
#endif
|
||
|
||
default:
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
}
|
||
}
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function
|
||
*/
|
||
int rsa_rsassa_pss_verify_ext( rsa_context *ctx,
|
||
int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
int mode,
|
||
md_type_t md_alg,
|
||
unsigned int hashlen,
|
||
const unsigned char *hash,
|
||
md_type_t mgf1_hash_id,
|
||
int expected_salt_len,
|
||
const unsigned char *sig )
|
||
{
|
||
int ret;
|
||
size_t siglen;
|
||
unsigned char *p;
|
||
unsigned char buf[POLARSSL_MPI_MAX_SIZE];
|
||
unsigned char result[POLARSSL_MD_MAX_SIZE];
|
||
unsigned char zeros[8];
|
||
unsigned int hlen;
|
||
size_t slen, msb;
|
||
const md_info_t *md_info;
|
||
md_context_t md_ctx;
|
||
|
||
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V21 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
siglen = ctx->len;
|
||
|
||
if( siglen < 16 || siglen > sizeof( buf ) )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
ret = ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, sig, buf )
|
||
: rsa_private( ctx, f_rng, p_rng, sig, buf );
|
||
|
||
if( ret != 0 )
|
||
return( ret );
|
||
|
||
p = buf;
|
||
|
||
if( buf[siglen - 1] != 0xBC )
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
|
||
if( md_alg != POLARSSL_MD_NONE )
|
||
{
|
||
// Gather length of hash to sign
|
||
//
|
||
md_info = md_info_from_type( md_alg );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
hashlen = md_get_size( md_info );
|
||
}
|
||
|
||
md_info = md_info_from_type( mgf1_hash_id );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
hlen = md_get_size( md_info );
|
||
slen = siglen - hlen - 1; /* Currently length of salt + padding */
|
||
|
||
memset( zeros, 0, 8 );
|
||
|
||
// Note: EMSA-PSS verification is over the length of N - 1 bits
|
||
//
|
||
msb = mpi_msb( &ctx->N ) - 1;
|
||
|
||
// Compensate for boundary condition when applying mask
|
||
//
|
||
if( msb % 8 == 0 )
|
||
{
|
||
p++;
|
||
siglen -= 1;
|
||
}
|
||
if( buf[0] >> ( 8 - siglen * 8 + msb ) )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
md_init( &md_ctx );
|
||
md_init_ctx( &md_ctx, md_info );
|
||
|
||
mgf_mask( p, siglen - hlen - 1, p + siglen - hlen - 1, hlen, &md_ctx );
|
||
|
||
buf[0] &= 0xFF >> ( siglen * 8 - msb );
|
||
|
||
while( p < buf + siglen && *p == 0 )
|
||
p++;
|
||
|
||
if( p == buf + siglen ||
|
||
*p++ != 0x01 )
|
||
{
|
||
md_free( &md_ctx );
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
}
|
||
|
||
/* Actual salt len */
|
||
slen -= p - buf;
|
||
|
||
if( expected_salt_len != RSA_SALT_LEN_ANY &&
|
||
slen != (size_t) expected_salt_len )
|
||
{
|
||
md_free( &md_ctx );
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
}
|
||
|
||
// Generate H = Hash( M' )
|
||
//
|
||
md_starts( &md_ctx );
|
||
md_update( &md_ctx, zeros, 8 );
|
||
md_update( &md_ctx, hash, hashlen );
|
||
md_update( &md_ctx, p, slen );
|
||
md_finish( &md_ctx, result );
|
||
|
||
md_free( &md_ctx );
|
||
|
||
if( memcmp( p + slen, result, hlen ) == 0 )
|
||
return( 0 );
|
||
else
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
}
|
||
|
||
/*
|
||
* Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function
|
||
*/
|
||
int rsa_rsassa_pss_verify( rsa_context *ctx,
|
||
int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
int mode,
|
||
md_type_t md_alg,
|
||
unsigned int hashlen,
|
||
const unsigned char *hash,
|
||
const unsigned char *sig )
|
||
{
|
||
md_type_t mgf1_hash_id = ( ctx->hash_id != POLARSSL_MD_NONE )
|
||
? (md_type_t) ctx->hash_id
|
||
: md_alg;
|
||
|
||
return( rsa_rsassa_pss_verify_ext( ctx, f_rng, p_rng, mode,
|
||
md_alg, hashlen, hash,
|
||
mgf1_hash_id, RSA_SALT_LEN_ANY,
|
||
sig ) );
|
||
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V21 */
|
||
|
||
#if defined(POLARSSL_PKCS1_V15)
|
||
/*
|
||
* Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function
|
||
*/
|
||
int rsa_rsassa_pkcs1_v15_verify( rsa_context *ctx,
|
||
int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
int mode,
|
||
md_type_t md_alg,
|
||
unsigned int hashlen,
|
||
const unsigned char *hash,
|
||
const unsigned char *sig )
|
||
{
|
||
int ret;
|
||
size_t len, siglen, asn1_len;
|
||
unsigned char *p, *end;
|
||
unsigned char buf[POLARSSL_MPI_MAX_SIZE];
|
||
md_type_t msg_md_alg;
|
||
const md_info_t *md_info;
|
||
asn1_buf oid;
|
||
|
||
if( mode == RSA_PRIVATE && ctx->padding != RSA_PKCS_V15 )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
siglen = ctx->len;
|
||
|
||
if( siglen < 16 || siglen > sizeof( buf ) )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
|
||
ret = ( mode == RSA_PUBLIC )
|
||
? rsa_public( ctx, sig, buf )
|
||
: rsa_private( ctx, f_rng, p_rng, sig, buf );
|
||
|
||
if( ret != 0 )
|
||
return( ret );
|
||
|
||
p = buf;
|
||
|
||
if( *p++ != 0 || *p++ != RSA_SIGN )
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
|
||
while( *p != 0 )
|
||
{
|
||
if( p >= buf + siglen - 1 || *p != 0xFF )
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
p++;
|
||
}
|
||
p++;
|
||
|
||
len = siglen - ( p - buf );
|
||
|
||
if( len == hashlen && md_alg == POLARSSL_MD_NONE )
|
||
{
|
||
if( memcmp( p, hash, hashlen ) == 0 )
|
||
return( 0 );
|
||
else
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
}
|
||
|
||
md_info = md_info_from_type( md_alg );
|
||
if( md_info == NULL )
|
||
return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
|
||
hashlen = md_get_size( md_info );
|
||
|
||
end = p + len;
|
||
|
||
// Parse the ASN.1 structure inside the PKCS#1 v1.5 structure
|
||
//
|
||
if( ( ret = asn1_get_tag( &p, end, &asn1_len,
|
||
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( asn1_len + 2 != len )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( ( ret = asn1_get_tag( &p, end, &asn1_len,
|
||
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( asn1_len + 6 + hashlen != len )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( ( ret = asn1_get_tag( &p, end, &oid.len, ASN1_OID ) ) != 0 )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
oid.p = p;
|
||
p += oid.len;
|
||
|
||
if( oid_get_md_alg( &oid, &msg_md_alg ) != 0 )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( md_alg != msg_md_alg )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
/*
|
||
* assume the algorithm parameters must be NULL
|
||
*/
|
||
if( ( ret = asn1_get_tag( &p, end, &asn1_len, ASN1_NULL ) ) != 0 )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( ( ret = asn1_get_tag( &p, end, &asn1_len, ASN1_OCTET_STRING ) ) != 0 )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( asn1_len != hashlen )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
if( memcmp( p, hash, hashlen ) != 0 )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
p += hashlen;
|
||
|
||
if( p != end )
|
||
return( POLARSSL_ERR_RSA_VERIFY_FAILED );
|
||
|
||
return( 0 );
|
||
}
|
||
#endif /* POLARSSL_PKCS1_V15 */
|
||
|
||
/*
|
||
* Do an RSA operation and check the message digest
|
||
*/
|
||
int rsa_pkcs1_verify( rsa_context *ctx,
|
||
int (*f_rng)(void *, unsigned char *, size_t),
|
||
void *p_rng,
|
||
int mode,
|
||
md_type_t md_alg,
|
||
unsigned int hashlen,
|
||
const unsigned char *hash,
|
||
const unsigned char *sig )
|
||
{
|
||
switch( ctx->padding )
|
||
{
|
||
#if defined(POLARSSL_PKCS1_V15)
|
||
case RSA_PKCS_V15:
|
||
return rsa_rsassa_pkcs1_v15_verify( ctx, f_rng, p_rng, mode, md_alg,
|
||
hashlen, hash, sig );
|
||
#endif
|
||
|
||
#if defined(POLARSSL_PKCS1_V21)
|
||
case RSA_PKCS_V21:
|
||
return rsa_rsassa_pss_verify( ctx, f_rng, p_rng, mode, md_alg,
|
||
hashlen, hash, sig );
|
||
#endif
|
||
|
||
default:
|
||
return( POLARSSL_ERR_RSA_INVALID_PADDING );
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Copy the components of an RSA key
|
||
*/
|
||
int rsa_copy( rsa_context *dst, const rsa_context *src )
|
||
{
|
||
int ret;
|
||
|
||
dst->ver = src->ver;
|
||
dst->len = src->len;
|
||
|
||
MPI_CHK( mpi_copy( &dst->N, &src->N ) );
|
||
MPI_CHK( mpi_copy( &dst->E, &src->E ) );
|
||
|
||
MPI_CHK( mpi_copy( &dst->D, &src->D ) );
|
||
MPI_CHK( mpi_copy( &dst->P, &src->P ) );
|
||
MPI_CHK( mpi_copy( &dst->Q, &src->Q ) );
|
||
MPI_CHK( mpi_copy( &dst->DP, &src->DP ) );
|
||
MPI_CHK( mpi_copy( &dst->DQ, &src->DQ ) );
|
||
MPI_CHK( mpi_copy( &dst->QP, &src->QP ) );
|
||
|
||
MPI_CHK( mpi_copy( &dst->RN, &src->RN ) );
|
||
MPI_CHK( mpi_copy( &dst->RP, &src->RP ) );
|
||
MPI_CHK( mpi_copy( &dst->RQ, &src->RQ ) );
|
||
|
||
MPI_CHK( mpi_copy( &dst->Vi, &src->Vi ) );
|
||
MPI_CHK( mpi_copy( &dst->Vf, &src->Vf ) );
|
||
|
||
dst->padding = src->padding;
|
||
dst->hash_id = src->hash_id;
|
||
|
||
cleanup:
|
||
if( ret != 0 )
|
||
rsa_free( dst );
|
||
|
||
return( ret );
|
||
}
|
||
|
||
/*
|
||
* Free the components of an RSA key
|
||
*/
|
||
void rsa_free( rsa_context *ctx )
|
||
{
|
||
mpi_free( &ctx->Vi ); mpi_free( &ctx->Vf );
|
||
mpi_free( &ctx->RQ ); mpi_free( &ctx->RP ); mpi_free( &ctx->RN );
|
||
mpi_free( &ctx->QP ); mpi_free( &ctx->DQ ); mpi_free( &ctx->DP );
|
||
mpi_free( &ctx->Q ); mpi_free( &ctx->P ); mpi_free( &ctx->D );
|
||
mpi_free( &ctx->E ); mpi_free( &ctx->N );
|
||
|
||
#if defined(POLARSSL_THREADING_C)
|
||
polarssl_mutex_free( &ctx->mutex );
|
||
#endif
|
||
}
|
||
|
||
#if defined(POLARSSL_SELF_TEST)
|
||
|
||
#include "polarssl/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 RSA_DP "C1ACF567564274FB07A0BBAD5D26E298" \
|
||
"3C94D22288ACD763FD8E5600ED4A702D" \
|
||
"F84198A5F06C2E72236AE490C93F07F8" \
|
||
"3CC559CD27BC2D1CA488811730BB5725"
|
||
|
||
#define RSA_DQ "4959CBF6F8FEF750AEE6977C155579C7" \
|
||
"D8AAEA56749EA28623272E4F7D0592AF" \
|
||
"7C1F1313CAC9471B5C523BFE592F517B" \
|
||
"407A1BD76C164B93DA2D32A383E58357"
|
||
|
||
#define RSA_QP "9AE7FBC99546432DF71896FC239EADAE" \
|
||
"F38D18D2B2F0E2DD275AA977E2BF4411" \
|
||
"F5A3B2A5D33605AEBBCCBA7FEB9F2D2F" \
|
||
"A74206CEC169D74BF5A8C50D6F48EA08"
|
||
|
||
#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(POLARSSL_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 /* POLARSSL_PKCS1_V15 */
|
||
|
||
/*
|
||
* Checkup routine
|
||
*/
|
||
int rsa_self_test( int verbose )
|
||
{
|
||
int ret = 0;
|
||
#if defined(POLARSSL_PKCS1_V15)
|
||
size_t len;
|
||
rsa_context rsa;
|
||
unsigned char rsa_plaintext[PT_LEN];
|
||
unsigned char rsa_decrypted[PT_LEN];
|
||
unsigned char rsa_ciphertext[KEY_LEN];
|
||
#if defined(POLARSSL_SHA1_C)
|
||
unsigned char sha1sum[20];
|
||
#endif
|
||
|
||
rsa_init( &rsa, RSA_PKCS_V15, 0 );
|
||
|
||
rsa.len = KEY_LEN;
|
||
MPI_CHK( mpi_read_string( &rsa.N , 16, RSA_N ) );
|
||
MPI_CHK( mpi_read_string( &rsa.E , 16, RSA_E ) );
|
||
MPI_CHK( mpi_read_string( &rsa.D , 16, RSA_D ) );
|
||
MPI_CHK( mpi_read_string( &rsa.P , 16, RSA_P ) );
|
||
MPI_CHK( mpi_read_string( &rsa.Q , 16, RSA_Q ) );
|
||
MPI_CHK( mpi_read_string( &rsa.DP, 16, RSA_DP ) );
|
||
MPI_CHK( mpi_read_string( &rsa.DQ, 16, RSA_DQ ) );
|
||
MPI_CHK( mpi_read_string( &rsa.QP, 16, RSA_QP ) );
|
||
|
||
if( verbose != 0 )
|
||
polarssl_printf( " RSA key validation: " );
|
||
|
||
if( rsa_check_pubkey( &rsa ) != 0 ||
|
||
rsa_check_privkey( &rsa ) != 0 )
|
||
{
|
||
if( verbose != 0 )
|
||
polarssl_printf( "failed\n" );
|
||
|
||
return( 1 );
|
||
}
|
||
|
||
if( verbose != 0 )
|
||
polarssl_printf( "passed\n PKCS#1 encryption : " );
|
||
|
||
memcpy( rsa_plaintext, RSA_PT, PT_LEN );
|
||
|
||
if( rsa_pkcs1_encrypt( &rsa, myrand, NULL, RSA_PUBLIC, PT_LEN,
|
||
rsa_plaintext, rsa_ciphertext ) != 0 )
|
||
{
|
||
if( verbose != 0 )
|
||
polarssl_printf( "failed\n" );
|
||
|
||
return( 1 );
|
||
}
|
||
|
||
if( verbose != 0 )
|
||
polarssl_printf( "passed\n PKCS#1 decryption : " );
|
||
|
||
if( rsa_pkcs1_decrypt( &rsa, myrand, NULL, RSA_PRIVATE, &len,
|
||
rsa_ciphertext, rsa_decrypted,
|
||
sizeof(rsa_decrypted) ) != 0 )
|
||
{
|
||
if( verbose != 0 )
|
||
polarssl_printf( "failed\n" );
|
||
|
||
return( 1 );
|
||
}
|
||
|
||
if( memcmp( rsa_decrypted, rsa_plaintext, len ) != 0 )
|
||
{
|
||
if( verbose != 0 )
|
||
polarssl_printf( "failed\n" );
|
||
|
||
return( 1 );
|
||
}
|
||
|
||
#if defined(POLARSSL_SHA1_C)
|
||
if( verbose != 0 )
|
||
polarssl_printf( "passed\n PKCS#1 data sign : " );
|
||
|
||
sha1( rsa_plaintext, PT_LEN, sha1sum );
|
||
|
||
if( rsa_pkcs1_sign( &rsa, myrand, NULL, RSA_PRIVATE, POLARSSL_MD_SHA1, 0,
|
||
sha1sum, rsa_ciphertext ) != 0 )
|
||
{
|
||
if( verbose != 0 )
|
||
polarssl_printf( "failed\n" );
|
||
|
||
return( 1 );
|
||
}
|
||
|
||
if( verbose != 0 )
|
||
polarssl_printf( "passed\n PKCS#1 sig. verify: " );
|
||
|
||
if( rsa_pkcs1_verify( &rsa, NULL, NULL, RSA_PUBLIC, POLARSSL_MD_SHA1, 0,
|
||
sha1sum, rsa_ciphertext ) != 0 )
|
||
{
|
||
if( verbose != 0 )
|
||
polarssl_printf( "failed\n" );
|
||
|
||
return( 1 );
|
||
}
|
||
|
||
if( verbose != 0 )
|
||
polarssl_printf( "passed\n\n" );
|
||
#endif /* POLARSSL_SHA1_C */
|
||
|
||
cleanup:
|
||
rsa_free( &rsa );
|
||
#else /* POLARSSL_PKCS1_V15 */
|
||
((void) verbose);
|
||
#endif /* POLARSSL_PKCS1_V15 */
|
||
return( ret );
|
||
}
|
||
|
||
#endif /* POLARSSL_SELF_TEST */
|
||
|
||
#endif /* POLARSSL_RSA_C */
|