1 /*
2  *  Public key-based signature verification program
3  *
4  *  Copyright The Mbed TLS Contributors
5  *  SPDX-License-Identifier: Apache-2.0
6  *
7  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
8  *  not use this file except in compliance with the License.
9  *  You may obtain a copy of the License at
10  *
11  *  http://www.apache.org/licenses/LICENSE-2.0
12  *
13  *  Unless required by applicable law or agreed to in writing, software
14  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  *  See the License for the specific language governing permissions and
17  *  limitations under the License.
18  */
19 
20 #include "mbedtls/build_info.h"
21 
22 #if defined(MBEDTLS_PLATFORM_C)
23 #include "mbedtls/platform.h"
24 #else
25 #include <stdio.h>
26 #include <stdlib.h>
27 #define mbedtls_snprintf        snprintf
28 #define mbedtls_printf          printf
29 #define mbedtls_exit            exit
30 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
31 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
32 #endif /* MBEDTLS_PLATFORM_C */
33 
34 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_MD_C) || \
35     !defined(MBEDTLS_SHA256_C) || !defined(MBEDTLS_PK_PARSE_C) ||   \
36     !defined(MBEDTLS_FS_IO)
main(void)37 int main( void )
38 {
39     mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_MD_C and/or "
40            "MBEDTLS_SHA256_C and/or MBEDTLS_PK_PARSE_C and/or "
41            "MBEDTLS_FS_IO not defined.\n");
42     mbedtls_exit( 0 );
43 }
44 #else
45 
46 #include "mbedtls/error.h"
47 #include "mbedtls/md.h"
48 #include "mbedtls/pk.h"
49 
50 #include <stdio.h>
51 #include <string.h>
52 
53 
main(int argc,char * argv[])54 int main( int argc, char *argv[] )
55 {
56     FILE *f;
57     int ret = 1;
58     int exit_code = MBEDTLS_EXIT_FAILURE;
59     size_t i;
60     mbedtls_pk_context pk;
61     unsigned char hash[32];
62     unsigned char buf[MBEDTLS_PK_SIGNATURE_MAX_SIZE];
63     char filename[512];
64 
65     mbedtls_pk_init( &pk );
66 
67     if( argc != 3 )
68     {
69         mbedtls_printf( "usage: mbedtls_pk_verify <key_file> <filename>\n" );
70 
71 #if defined(_WIN32)
72         mbedtls_printf( "\n" );
73 #endif
74 
75         goto exit;
76     }
77 
78     mbedtls_printf( "\n  . Reading public key from '%s'", argv[1] );
79     fflush( stdout );
80 
81     if( ( ret = mbedtls_pk_parse_public_keyfile( &pk, argv[1] ) ) != 0 )
82     {
83         mbedtls_printf( " failed\n  ! mbedtls_pk_parse_public_keyfile returned -0x%04x\n", (unsigned int) -ret );
84         goto exit;
85     }
86 
87     /*
88      * Extract the signature from the file
89      */
90     mbedtls_snprintf( filename, sizeof(filename), "%s.sig", argv[2] );
91 
92     if( ( f = fopen( filename, "rb" ) ) == NULL )
93     {
94         mbedtls_printf( "\n  ! Could not open %s\n\n", filename );
95         goto exit;
96     }
97 
98     i = fread( buf, 1, sizeof(buf), f );
99 
100     fclose( f );
101 
102     /*
103      * Compute the SHA-256 hash of the input file and
104      * verify the signature
105      */
106     mbedtls_printf( "\n  . Verifying the SHA-256 signature" );
107     fflush( stdout );
108 
109     if( ( ret = mbedtls_md_file(
110                     mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
111                     argv[2], hash ) ) != 0 )
112     {
113         mbedtls_printf( " failed\n  ! Could not open or read %s\n\n", argv[2] );
114         goto exit;
115     }
116 
117     if( ( ret = mbedtls_pk_verify( &pk, MBEDTLS_MD_SHA256, hash, 0,
118                            buf, i ) ) != 0 )
119     {
120         mbedtls_printf( " failed\n  ! mbedtls_pk_verify returned -0x%04x\n", (unsigned int) -ret );
121         goto exit;
122     }
123 
124     mbedtls_printf( "\n  . OK (the signature is valid)\n\n" );
125 
126     exit_code = MBEDTLS_EXIT_SUCCESS;
127 
128 exit:
129     mbedtls_pk_free( &pk );
130 
131 #if defined(MBEDTLS_ERROR_C)
132     if( exit_code != MBEDTLS_EXIT_SUCCESS )
133     {
134         mbedtls_strerror( ret, (char *) buf, sizeof(buf) );
135         mbedtls_printf( "  !  Last error was: %s\n", buf );
136     }
137 #endif
138 
139 #if defined(_WIN32)
140     mbedtls_printf( "  + Press Enter to exit this program.\n" );
141     fflush( stdout ); getchar();
142 #endif
143 
144     mbedtls_exit( exit_code );
145 }
146 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_SHA256_C &&
147           MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO */
148