1 files changed, 122 insertions, 0 deletions
diff --git a/g10/encr-data.c b/g10/encr-data.c
new file mode 100644
index 000000000..5c047e90d
--- /dev/null
+++ b/g10/encr-data.c
@@ -0,0 +1,122 @@
+/* encr-data.c -  process an encrypted data packet
+ *	Copyright (c) 1997 by Werner Koch (dd9jn)
+ *
+ * This file is part of G10.
+ *
+ * G10 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.
+ *
+ * G10 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 <assert.h>
+#include "util.h"
+#include "memory.h"
+#include "packet.h"
+#include "mpi.h"
+#include "cipher.h"
+
+
+static int decode_filter( void *opaque, int control, IOBUF a,
+					byte *buf, size_t *ret_len);
+
+typedef struct {
+    BLOWFISH_context *bf_ctx;
+} decode_filter_ctx_t;
+
+
+
+/****************
+ * Decrypt the data, specified by ED with the key DEK.
+ */
+int
+decrypt_data( PKT_encr_data *ed, DEK *dek )
+{
+    decode_filter_ctx_t dfx;
+    byte *p;
+    int c, i;
+    byte temp[16];
+
+
+    if( dek->algo != CIPHER_ALGO_BLOWFISH )
+	return G10ERR_CIPHER_ALGO;
+    if( ed->len && ed->len < 10 )
+	log_bug("Nanu\n");   /* oops: found a bug */
+
+    dfx.bf_ctx = m_alloc_secure( sizeof *dfx.bf_ctx );
+    blowfish_setkey( dfx.bf_ctx, dek->key, dek->keylen	);
+    blowfish_setiv( dfx.bf_ctx, NULL );
+
+    if( ed->len ) {
+	iobuf_set_limit( ed->buf, ed->len );
+
+	for(i=0; i < 10 && ed->len; i++, ed->len-- )
+	    temp[i] = iobuf_get(ed->buf);
+    }
+    else {
+	for(i=0; i < 10; i++ )
+	    if( (c=iobuf_get(ed->buf)) == -1 )
+		break;
+	    else
+		temp[i] = c;
+    }
+    blowfish_decode_cfb( dfx.bf_ctx, temp, temp, 10);
+    p = temp;
+    if( p[6] != p[8] || p[7] != p[9] ) {
+	m_free(dfx.bf_ctx);
+	return G10ERR_BAD_KEY;
+    }
+    iobuf_push_filter( ed->buf, decode_filter, &dfx );
+    proc_packets(ed->buf);
+    iobuf_pop_filter( ed->buf, decode_filter, &dfx );
+    if( ed->len )
+	iobuf_set_limit( ed->buf, 0 ); /* disable the readlimit */
+    else
+	iobuf_clear_eof( ed->buf );
+    ed->buf = NULL;
+    m_free(dfx.bf_ctx);
+    return 0;
+}
+
+static int
+decode_filter( void *opaque, int control, IOBUF a, byte *buf, size_t *ret_len)
+{
+    decode_filter_ctx_t *fc = opaque;
+    size_t n, size = *ret_len;
+    int rc = 0;
+    int c;
+
+    if( control == IOBUFCTRL_UNDERFLOW ) {
+	assert(a);
+	for(n=0; n < size; n++ ) {
+	    if( (c = iobuf_get(a)) == -1 )
+		break;
+	    buf[n] = c;
+	}
+
+	if( n )
+	    blowfish_decode_cfb( fc->bf_ctx, buf, buf, n);
+	else
+	    rc = -1; /* eof */
+	*ret_len = n;
+    }
+    else if( control == IOBUFCTRL_DESC ) {
+	*(char**)buf = "decode_filter";
+    }
+    return rc;
+}
+
+