Add ecdsa example program
diff --git a/programs/pkey/ecdsa.c b/programs/pkey/ecdsa.c
new file mode 100644
index 0000000..06f1123
--- /dev/null
+++ b/programs/pkey/ecdsa.c
@@ -0,0 +1,196 @@
+/*
+ * Example ECDSA program
+ *
+ * Copyright (C) 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.
+ */
+
+#include "polarssl/config.h"
+
+#include "polarssl/entropy.h"
+#include "polarssl/ctr_drbg.h"
+#include "polarssl/ecdsa.h"
+
+#include <string.h>
+#include <stdio.h>
+
+/*
+ * Uncomment to force use of a specific curve
+#define ECPARAMS POLARSSL_ECP_DP_SECP256R1
+ */
+
+#if !defined(ECPARAMS)
+#if defined(POLARSSL_ECP_DP_SECP192R1_ENABLED)
+#define ECPARAMS POLARSSL_ECP_DP_SECP192R1
+#elif defined(POLARSSL_ECP_DP_SECP224R1_ENABLED)
+#define ECPARAMS POLARSSL_ECP_DP_SECP224R1
+#elif defined(POLARSSL_ECP_DP_SECP256R1_ENABLED)
+#define ECPARAMS POLARSSL_ECP_DP_SECP256R1
+#elif defined(POLARSSL_ECP_DP_SECP384R1_ENABLED)
+#define ECPARAMS POLARSSL_ECP_DP_SECP384R1
+#elif defined(POLARSSL_ECP_DP_SECP521R1_ENABLED)
+#define ECPARAMS POLARSSL_ECP_DP_SECP521R1
+#endif
+#endif /* !defined(ECPARAMS) */
+
+#if !defined(POLARSSL_BIGNUM_C) || !defined(POLARSSL_ECDSA_C) || \
+ !defined(POLARSSL_ENTROPY_C) || !defined(POLARSSL_CTR_DRBG_C) || \
+ !defined(ECPARAMS)
+int main( int argc, char *argv[] )
+{
+ ((void) argc);
+ ((void) argv);
+
+ printf("POLARSSL_BIGNUM_C and/or POLARSSL_ECDSA_C and/or "
+ "POLARSSL_ENTROPY_C and/or POLARSSL_CTR_DRBG_C not defined,"
+ "and/or not EC domain parameter available\n" );
+ return( 0 );
+}
+#else
+int main( int argc, char *argv[] )
+{
+ int ret;
+ ecdsa_context ctx_sign, ctx_verify;
+ entropy_context entropy;
+ ctr_drbg_context ctr_drbg;
+ unsigned char hash[] = "This should be the hash of a message.";
+ unsigned char sig[512];
+ size_t sig_len;
+ const char *pers = "ecdsa";
+ ((void) argv);
+
+ ecdsa_init( &ctx_sign );
+ ecdsa_init( &ctx_verify );
+
+ memset(sig, 0, sizeof( sig ) );
+ ret = 1;
+
+ if( argc != 1 )
+ {
+ printf( "usage: ecdsa\n" );
+
+#if defined(_WIN32)
+ printf( "\n" );
+#endif
+
+ goto exit;
+ }
+
+ /*
+ * Generate a key pair for signing
+ */
+ printf( "\n . Seeding the random number generator..." );
+ fflush( stdout );
+
+ entropy_init( &entropy );
+ if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
+ (const unsigned char *) pers,
+ strlen( pers ) ) ) != 0 )
+ {
+ printf( " failed\n ! ctr_drbg_init returned %d\n", ret );
+ goto exit;
+ }
+
+ printf( " ok\n . Generating key pair..." );
+ fflush( stdout );
+
+ if( ( ret = ecdsa_genkey( &ctx_sign, ECPARAMS,
+ ctr_drbg_random, &ctr_drbg ) ) != 0 )
+ {
+ printf( " failed\n ! ecdsa_genkey returned %d\n", ret );
+ goto exit;
+ }
+
+ printf( " ok (key size: %d bits)\n", (int) ctx_sign.grp.pbits );
+
+ /*
+ * Sign some message hash
+ */
+ printf( " . Signing message..." );
+ fflush( stdout );
+
+ if( ( ret = ecdsa_write_signature( &ctx_sign,
+ hash, sizeof( hash ),
+ sig, &sig_len,
+ ctr_drbg_random, &ctr_drbg ) ) != 0 )
+ {
+ printf( " failed\n ! ecdsa_genkey returned %d\n", ret );
+ goto exit;
+ }
+ printf( " ok\n" );
+
+ /*
+ * Signature is serialized as defined by RFC 4492 p. 20,
+ * but one can also access 'r' and 's' directly from the context
+ */
+#ifdef POLARSSL_FS_IO
+ mpi_write_file( " r = ", &ctx_sign.r, 16, NULL );
+ mpi_write_file( " s = ", &ctx_sign.s, 16, NULL );
+#endif
+
+ /*
+ * Transfer public information to verifying context
+ */
+ printf( " . Preparing verification context..." );
+ fflush( stdout );
+
+ if( ( ret = ecp_use_known_dp( &ctx_verify.grp, ctx_sign.grp.id ) ) != 0 )
+ {
+ printf( " failed\n ! ecp_use_known_dp returned %d\n", ret );
+ goto exit;
+ }
+
+ if( ( ret = ecp_copy( &ctx_verify.Q, &ctx_sign.Q ) ) != 0 )
+ {
+ printf( " failed\n ! ecp_copy returned %d\n", ret );
+ goto exit;
+ }
+
+ ret = 0;
+
+ /*
+ * Verify signature
+ */
+ printf( " ok\n . Verifying signature..." );
+ fflush( stdout );
+
+ if( ( ret = ecdsa_read_signature( &ctx_verify,
+ hash, sizeof( hash ),
+ sig, sig_len ) ) != 0 )
+ {
+ printf( " failed\n ! ecdsa_read_signature returned %d\n", ret );
+ goto exit;
+ }
+
+ printf( " ok\n" );
+
+exit:
+
+#if defined(_WIN32)
+ printf( " + Press Enter to exit this program.\n" );
+ fflush( stdout ); getchar();
+#endif
+
+ return( ret );
+}
+#endif /* POLARSSL_BIGNUM_C && POLARSSL_ECDSA_C &&
+ POLARSSL_ENTROPY_C && POLARSSL_CTR_DRBG_C &&
+ ECPARAMS */