/* * RSA/SHA-256 signature verification program * * 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) */ #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #if defined(MBEDTLS_PLATFORM_C) #include "mbedtls/platform.h" #else #include <stdio.h> #include <stdlib.h> #define mbedtls_printf printf #define mbedtls_snprintf snprintf #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE #endif /* MBEDTLS_PLATFORM_C */ #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_RSA_C) || \ !defined(MBEDTLS_SHA256_C) || !defined(MBEDTLS_MD_C) || \ !defined(MBEDTLS_FS_IO) int main( void ) { mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_RSA_C and/or " "MBEDTLS_MD_C and/or " "MBEDTLS_SHA256_C and/or MBEDTLS_FS_IO not defined.\n"); return( 0 ); } #else #include "mbedtls/rsa.h" #include "mbedtls/md.h" #include <stdio.h> #include <string.h> int main( int argc, char *argv[] ) { FILE *f; int ret = 1, c; int exit_code = MBEDTLS_EXIT_FAILURE; size_t i; mbedtls_rsa_context rsa; unsigned char hash[32]; unsigned char buf[MBEDTLS_MPI_MAX_SIZE]; char filename[512]; mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 ); if( argc != 2 ) { mbedtls_printf( "usage: rsa_verify <filename>\n" ); #if defined(_WIN32) mbedtls_printf( "\n" ); #endif goto exit; } mbedtls_printf( "\n . Reading public key from rsa_pub.txt" ); fflush( stdout ); if( ( f = fopen( "rsa_pub.txt", "rb" ) ) == NULL ) { mbedtls_printf( " failed\n ! Could not open rsa_pub.txt\n" \ " ! Please run rsa_genkey first\n\n" ); goto exit; } if( ( ret = mbedtls_mpi_read_file( &rsa.N, 16, f ) ) != 0 || ( ret = mbedtls_mpi_read_file( &rsa.E, 16, f ) ) != 0 ) { mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n", ret ); fclose( f ); goto exit; } rsa.len = ( mbedtls_mpi_bitlen( &rsa.N ) + 7 ) >> 3; fclose( f ); /* * Extract the RSA signature from the text file */ mbedtls_snprintf( filename, sizeof(filename), "%s.sig", argv[1] ); if( ( f = fopen( filename, "rb" ) ) == NULL ) { mbedtls_printf( "\n ! Could not open %s\n\n", filename ); goto exit; } i = 0; while( fscanf( f, "%02X", &c ) > 0 && i < (int) sizeof( buf ) ) buf[i++] = (unsigned char) c; fclose( f ); if( i != rsa.len ) { mbedtls_printf( "\n ! Invalid RSA signature format\n\n" ); goto exit; } /* * Compute the SHA-256 hash of the input file and * verify the signature */ mbedtls_printf( "\n . Verifying the RSA/SHA-256 signature" ); fflush( stdout ); if( ( ret = mbedtls_md_file( mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ), argv[1], hash ) ) != 0 ) { mbedtls_printf( " failed\n ! Could not open or read %s\n\n", argv[1] ); goto exit; } if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL, MBEDTLS_RSA_PUBLIC, MBEDTLS_MD_SHA256, 20, hash, buf ) ) != 0 ) { mbedtls_printf( " failed\n ! mbedtls_rsa_pkcs1_verify returned -0x%0x\n\n", -ret ); goto exit; } mbedtls_printf( "\n . OK (the signature is valid)\n\n" ); exit_code = MBEDTLS_EXIT_SUCCESS; exit: mbedtls_rsa_free( &rsa ); #if defined(_WIN32) mbedtls_printf( " + Press Enter to exit this program.\n" ); fflush( stdout ); getchar(); #endif return( exit_code ); } #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_RSA_C && MBEDTLS_SHA256_C && MBEDTLS_FS_IO */