partial DSA support

1 files changed, 71 insertions, 0 deletions

diff --git a/g10/dsa.c b/g10/dsa.c
new file mode 100644
index 000000000..1c4f8945d
--- /dev/null
+++ b/g10/dsa.c
@@ -0,0 +1,71 @@
+/* dsa.c
+ *	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 "options.h"
+#include "packet.h"
+#include "errors.h"
+#include "iobuf.h"
+#include "keydb.h"
+#include "memory.h"
+#include "util.h"
+#include "main.h"
+
+
+void
+g10_dsa_sign( PKT_secret_cert *skc, PKT_signature *sig,
+	      MD_HANDLE md, int digest_algo )
+{
+    DSA_secret_key skey;
+    MPI frame;
+    byte *dp;
+
+    assert( sig->pubkey_algo == PUBKEY_ALGO_DSA );
+    if( !digest_algo )
+	digest_algo = md_get_algo(md);
+
+    dp = md_read( md, digest_algo );
+    keyid_from_skc( skc, sig->keyid );
+    sig->digest_algo = digest_algo;
+    sig->digest_start[0] = dp[0];
+    sig->digest_start[1] = dp[1];
+    sig->d.dsa.r = mpi_alloc( mpi_get_nlimbs(skc->d.dsa.p) );
+    sig->d.dsa.s = mpi_alloc( mpi_get_nlimbs(skc->d.dsa.p) );
+    frame = encode_md_value( md, mpi_get_nbits(skc->d.dsa.p));
+    skey.p = skc->d.elg.p;
+    skey.g = skc->d.elg.g;
+    skey.y = skc->d.elg.y;
+    skey.x = skc->d.elg.x;
+    dsa_sign( sig->d.dsa.r, sig->d.dsa.s, frame, &skey);
+    memset( &skey, 0, sizeof skey );
+    mpi_free(frame);
+    if( opt.verbose ) {
+	char *ustr = get_user_id_string( sig->keyid );
+	log_info("DSA signature from: %s\n", ustr );
+	m_free(ustr);
+    }
+}
+