Initial revision
diff --git a/compress.c b/compress.c
new file mode 100644
index 0000000..c3267f7
--- /dev/null
+++ b/compress.c
@@ -0,0 +1,160 @@
+/*
+
+compress.c
+
+Author: Tatu Ylonen <ylo@cs.hut.fi>
+
+Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ All rights reserved
+
+Created: Wed Oct 25 22:12:46 1995 ylo
+
+Interface to packet compression for ssh.
+
+*/
+
+#include "includes.h"
+RCSID("$Id: compress.c,v 1.1 1999/10/27 03:42:44 damien Exp $");
+
+#include "ssh.h"
+#include "buffer.h"
+#include "zlib.h"
+
+static z_stream incoming_stream;
+static z_stream outgoing_stream;
+
+/* Initializes compression; level is compression level from 1 to 9 (as in
+ gzip). */
+
+void buffer_compress_init(int level)
+{
+ debug("Enabling compression at level %d.", level);
+ if (level < 1 || level > 9)
+ fatal("Bad compression level %d.", level);
+ inflateInit(&incoming_stream);
+ deflateInit(&outgoing_stream, level);
+}
+
+/* Frees any data structures allocated for compression. */
+
+void buffer_compress_uninit()
+{
+ debug("compress outgoing: raw data %lu, compressed %lu, factor %.2f",
+ outgoing_stream.total_in, outgoing_stream.total_out,
+ outgoing_stream.total_in == 0 ? 0.0 :
+ (double)outgoing_stream.total_out / outgoing_stream.total_in);
+ debug("compress incoming: raw data %lu, compressed %lu, factor %.2f",
+ incoming_stream.total_out, incoming_stream.total_in,
+ incoming_stream.total_out == 0 ? 0.0 :
+ (double)incoming_stream.total_in / incoming_stream.total_out);
+ inflateEnd(&incoming_stream);
+ deflateEnd(&outgoing_stream);
+}
+
+/* Compresses the contents of input_buffer into output_buffer. All
+ packets compressed using this function will form a single
+ compressed data stream; however, data will be flushed at the end of
+ every call so that each output_buffer can be decompressed
+ independently (but in the appropriate order since they together
+ form a single compression stream) by the receiver. This appends
+ the compressed data to the output buffer. */
+
+void buffer_compress(Buffer *input_buffer, Buffer *output_buffer)
+{
+ char buf[4096];
+ int status;
+
+ /* This case is not handled below. */
+ if (buffer_len(input_buffer) == 0)
+ return;
+
+ /* Input is the contents of the input buffer. */
+ outgoing_stream.next_in = buffer_ptr(input_buffer);
+ outgoing_stream.avail_in = buffer_len(input_buffer);
+
+ /* Loop compressing until deflate() returns with avail_out != 0. */
+ do
+ {
+ /* Set up fixed-size output buffer. */
+ outgoing_stream.next_out = buf;
+ outgoing_stream.avail_out = sizeof(buf);
+
+ /* Compress as much data into the buffer as possible. */
+ status = deflate(&outgoing_stream, Z_PARTIAL_FLUSH);
+ switch (status)
+ {
+ case Z_OK:
+ /* Append compressed data to output_buffer. */
+ buffer_append(output_buffer, buf,
+ sizeof(buf) - outgoing_stream.avail_out);
+ break;
+ case Z_STREAM_END:
+ fatal("buffer_compress: deflate returned Z_STREAM_END");
+ /*NOTREACHED*/
+ case Z_STREAM_ERROR:
+ fatal("buffer_compress: deflate returned Z_STREAM_ERROR");
+ /*NOTREACHED*/
+ case Z_BUF_ERROR:
+ fatal("buffer_compress: deflate returned Z_BUF_ERROR");
+ /*NOTREACHED*/
+ default:
+ fatal("buffer_compress: deflate returned %d", status);
+ /*NOTREACHED*/
+ }
+ }
+ while (outgoing_stream.avail_out == 0);
+}
+
+/* Uncompresses the contents of input_buffer into output_buffer. All
+ packets uncompressed using this function will form a single
+ compressed data stream; however, data will be flushed at the end of
+ every call so that each output_buffer. This must be called for the
+ same size units that the buffer_compress was called, and in the
+ same order that buffers compressed with that. This appends the
+ uncompressed data to the output buffer. */
+
+void buffer_uncompress(Buffer *input_buffer, Buffer *output_buffer)
+{
+ char buf[4096];
+ int status;
+
+ incoming_stream.next_in = buffer_ptr(input_buffer);
+ incoming_stream.avail_in = buffer_len(input_buffer);
+
+ incoming_stream.next_out = buf;
+ incoming_stream.avail_out = sizeof(buf);
+
+ for (;;)
+ {
+ status = inflate(&incoming_stream, Z_PARTIAL_FLUSH);
+ switch (status)
+ {
+ case Z_OK:
+ buffer_append(output_buffer, buf,
+ sizeof(buf) - incoming_stream.avail_out);
+ incoming_stream.next_out = buf;
+ incoming_stream.avail_out = sizeof(buf);
+ break;
+ case Z_STREAM_END:
+ fatal("buffer_uncompress: inflate returned Z_STREAM_END");
+ /*NOTREACHED*/
+ case Z_DATA_ERROR:
+ fatal("buffer_uncompress: inflate returned Z_DATA_ERROR");
+ /*NOTREACHED*/
+ case Z_STREAM_ERROR:
+ fatal("buffer_uncompress: inflate returned Z_STREAM_ERROR");
+ /*NOTREACHED*/
+ case Z_BUF_ERROR:
+ /* Comments in zlib.h say that we should keep calling inflate()
+ until we get an error. This appears to be the error that we
+ get. */
+ return;
+ case Z_MEM_ERROR:
+ fatal("buffer_uncompress: inflate returned Z_MEM_ERROR");
+ /*NOTREACHED*/
+ default:
+ fatal("buffer_uncompress: inflate returned %d", status);
+ }
+ }
+}
+