Added pk_decrypt, pk_encrypt, pk_sign, pk_verify example applications
diff --git a/programs/pkey/pk_verify.c b/programs/pkey/pk_verify.c
new file mode 100644
index 0000000..68c0887
--- /dev/null
+++ b/programs/pkey/pk_verify.c
@@ -0,0 +1,145 @@
+/*
+ * Public key-based signature verification program
+ *
+ * Copyright (C) 2006-2013, Brainspark B.V.
+ *
+ * This file is part of PolarSSL (http://www.polarssl.org)
+ * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ * All rights reserved.
+ *
+ * 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.
+ */
+
+#ifndef _CRT_SECURE_NO_DEPRECATE
+#define _CRT_SECURE_NO_DEPRECATE 1
+#endif
+
+#include <string.h>
+#include <stdio.h>
+
+#include "polarssl/config.h"
+
+#include "polarssl/error.h"
+#include "polarssl/md.h"
+#include "polarssl/pk.h"
+#include "polarssl/sha1.h"
+
+#if defined _MSC_VER && !defined snprintf
+#define snprintf _snprintf
+#endif
+
+#if !defined(POLARSSL_BIGNUM_C) || \
+ !defined(POLARSSL_SHA1_C) || !defined(POLARSSL_PK_PARSE_C) || \
+ !defined(POLARSSL_FS_IO)
+int main( int argc, char *argv[] )
+{
+ ((void) argc);
+ ((void) argv);
+
+ printf("POLARSSL_BIGNUM_C and/or "
+ "POLARSSL_SHA1_C and/or POLARSSL_PK_PARSE_C and/or "
+ "POLARSSL_FS_IO not defined.\n");
+ return( 0 );
+}
+#else
+int main( int argc, char *argv[] )
+{
+ FILE *f;
+ int ret;
+ size_t i;
+ pk_context pk;
+ unsigned char hash[20];
+ unsigned char buf[POLARSSL_MPI_MAX_SIZE];
+ char filename[512];
+
+ ret = 1;
+ if( argc != 3 )
+ {
+ printf( "usage: pk_verify <key_file> <filename>\n" );
+
+#if defined(_WIN32)
+ printf( "\n" );
+#endif
+
+ goto exit;
+ }
+
+ printf( "\n . Reading public key from '%s'", argv[1] );
+ fflush( stdout );
+
+ pk_init( &pk );
+
+ if( ( ret = pk_parse_public_keyfile( &pk, argv[1] ) ) != 0 )
+ {
+ polarssl_strerror( ret, (char *) buf, sizeof(buf) );
+ printf( " failed\n ! pk_parse_public_keyfile returned -0x%04x - %s\n\n", -ret, buf );
+ goto exit;
+ }
+
+ /*
+ * Extract the signature from the text file
+ */
+ ret = 1;
+ snprintf( filename, sizeof(filename), "%s.sig", argv[2] );
+
+ if( ( f = fopen( filename, "rb" ) ) == NULL )
+ {
+ printf( "\n ! Could not open %s\n\n", filename );
+ goto exit;
+ }
+
+
+ i = fread( buf, 1, sizeof(buf), f );
+
+ fclose( f );
+
+ /*
+ * Compute the SHA-1 hash of the input file and compare
+ * it with the hash decrypted from the signature.
+ */
+ printf( "\n . Verifying the SHA-1 signature" );
+ fflush( stdout );
+
+ if( ( ret = sha1_file( argv[2], hash ) ) != 0 )
+ {
+ printf( " failed\n ! Could not open or read %s\n\n", argv[2] );
+ goto exit;
+ }
+
+ if( ( ret = pk_verify( &pk, POLARSSL_MD_SHA1, hash, 0,
+ buf, i ) ) != 0 )
+ {
+ polarssl_strerror( ret, (char *) buf, sizeof(buf) );
+ printf( " failed\n ! pk_verify returned -0x%04x - %s\n\n", -ret, buf );
+ goto exit;
+ }
+
+ printf( "\n . OK (the decrypted SHA-1 hash matches)\n\n" );
+
+ ret = 0;
+
+exit:
+ pk_free( &pk );
+
+#if defined(_WIN32)
+ printf( " + Press Enter to exit this program.\n" );
+ fflush( stdout ); getchar();
+#endif
+
+ return( ret );
+}
+#endif /* POLARSSL_BIGNUM_C && POLARSSL_SHA1_C &&
+ POLARSSL_PK_PARSE_C && POLARSSL_FS_IO */