1 files changed, 84 insertions, 0 deletions
diff --git a/cipher/pubkey.c b/cipher/pubkey.c
new file mode 100644
index 000000000..3ffc1ca33
--- /dev/null
+++ b/cipher/pubkey.c
@@ -0,0 +1,84 @@
+/* pubkey.c  -	pubkey dispatcher
+ *	Copyright (C) 1998 Free Software Foundation, Inc.
+ *
+ * This file is part of GNUPG.
+ *
+ * GNUPG 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.
+ *
+ * GNUPG 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include "util.h"
+#include "errors.h"
+#include "mpi.h"
+#include "cipher.h"
+#include "dynload.h"
+
+
+/****************
+ * This is the interface for the public key decryption.
+ * ALGO gives the algorithm to use and this implicitly determines
+ * the size of the arrays.
+ * result is a pointer to a mpi variable which will receive a
+ * newly allocated mpi or NULL in case of an error.
+ */
+int
+pubkey_decrypt( int algo, MPI *result, int ndata, MPI *data,
+				       int nskey, MPI *skey )
+{
+    MPI plain = NULL;
+
+    *result = NULL; /* so the caller can do always do an mpi_free */
+    if( DBG_CIPHER ) {
+	int i;
+	log_debug("pubkey_decrypt: algo=%d\n", algo );
+	for(i=0; i < nskey; i++ )
+	    log_mpidump("  skey:", skey[i] );
+	for(i=0; i < ndata; i++ )
+	    log_mpidump("  data:", data[i] );
+    }
+    if( is_ELGAMAL(algo) ) {
+	ELG_secret_key sk;
+	assert( ndata == 2 && nskey == 4 );
+	sk.p = skey[0];
+	sk.g = skey[1];
+	sk.y = skey[2];
+	sk.x = skey[3];
+	plain = mpi_alloc_secure( mpi_get_nlimbs( sk.p ) );
+	elg_decrypt( plain, data[0], data[1], &sk );
+    }
+    else if( is_RSA(k->pubkey_algo) ) {
+	RSA_secret_key sk;
+	assert( ndata == 1 && nskey == 6 );
+	sk.e = skey[0];
+	sk.n = skey[1];
+	sk.p = skey[2];
+	sk.q = skey[3];
+	sk.d = skey[4];
+	sk.u = skey[5];
+	plain = mpi_alloc_secure( mpi_get_nlimbs(sk.n) );
+	rsa_secret( plain, data[0], &sk );
+    }
+    else
+	return G10ERR_PUBKEY_ALGO;
+    *result = plain;
+    return 0;
+}
+
+