1 files changed, 101 insertions, 0 deletions
diff --git a/lib/gnutls_ecc.c b/lib/gnutls_ecc.c
new file mode 100644
index 0000000000..c15600836c
--- /dev/null
+++ b/lib/gnutls_ecc.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2011 Free Software Foundation, Inc.
+ *
+ * Author: Nikos Mavrogiannopoulos
+ *
+ * This file is part of GnuTLS.
+ *
+ * The GnuTLS is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA
+ *
+ */
+
+/* Helper functions for ECC handling 
+ * based on public domain code by Tom St. Dennis.
+ */
+#include <gnutls_int.h>
+#include <gnutls_mpi.h>
+#include <gnutls_ecc.h>
+#include <gnutls_algorithms.h>
+#include <gnutls_errors.h>
+
+int _gnutls_ecc_ansi_x963_export(ecc_curve_t curve, bigint_t x, bigint_t y, gnutls_datum_t * out)
+{
+   int numlen = _gnutls_ecc_curve_get_size(curve);
+   int byte_size, ret;
+   size_t size;
+   
+   if (numlen == 0)
+     return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
+   
+   out->size = 1 + 2*numlen;
+   
+   out->data = gnutls_malloc(out->size);
+   if (out->data == NULL)
+     return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
+
+   memset(out->data, 0, out->size);
+
+   /* store byte 0x04 */
+   out->data[0] = 0x04;
+
+   /* pad and store x */
+   byte_size = (_gnutls_mpi_get_nbits(x)+7)/8;
+   size = out->size - (1+(numlen-byte_size));
+   ret = _gnutls_mpi_print(x, &out->data[1+(numlen-byte_size)], &size);
+   if (ret < 0)
+     return gnutls_assert_val(ret);
+   
+   byte_size = (_gnutls_mpi_get_nbits(y)+7)/8;
+   size = out->size - (1+(numlen+numlen-byte_size));
+   ret = _gnutls_mpi_print(y, &out->data[1+numlen+numlen-byte_size], &size);
+   if (ret < 0)
+     return gnutls_assert_val(ret);
+
+   /* pad and store y */
+   return 0;
+}
+
+
+int _gnutls_ecc_ansi_x963_import(ecc_curve_t curve, const opaque *in, unsigned long inlen, bigint_t* x, bigint_t* y)
+{
+   int ret;
+   int numlen = _gnutls_ecc_curve_get_size(curve);
+ 
+   /* must be odd */
+   if ((inlen & 1) == 0 || numlen == 0) 
+     {
+       return GNUTLS_E_INVALID_REQUEST;
+     }
+
+   /* check for 4, 6 or 7 */
+   if (in[0] != 4 && in[0] != 6 && in[0] != 7) {
+      return gnutls_assert_val(GNUTLS_E_PARSING_ERROR);
+   }
+
+   /* read data */
+   ret = _gnutls_mpi_scan(x, in+1, (inlen-1)>>1);
+   if (ret < 0)
+     return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
+
+   ret = _gnutls_mpi_scan(y, in+1+((inlen-1)>>1), (inlen-1)>>1);
+   if (ret < 0)
+     {
+       _gnutls_mpi_release(x);
+       return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
+     }
+
+   return 0;
+}