1 files changed, 143 insertions, 0 deletions

diff --git a/other/openssh-reverse/compress.c b/other/openssh-reverse/compress.c
new file mode 100644
index 0000000..4ec2010
--- /dev/null
+++ b/other/openssh-reverse/compress.c
@@ -0,0 +1,143 @@
+/*
+ *
+ * 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("$OpenBSD: compress.c,v 1.8 2000/06/20 01:39:40 markus 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 = (unsigned char *) 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 = (unsigned char *)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;
+                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 = (unsigned char *) buffer_ptr(input_buffer);
+        incoming_stream.avail_in = buffer_len(input_buffer);
+
+        for (;;) {
+                /* Set up fixed-size output buffer. */
+                incoming_stream.next_out = (unsigned char *) buf;
+                incoming_stream.avail_out = sizeof(buf);
+
+                status = inflate(&incoming_stream, Z_PARTIAL_FLUSH);
+                switch (status) {
+                case Z_OK:
+                        buffer_append(output_buffer, buf,
+                            sizeof(buf) - incoming_stream.avail_out);
+                        break;
+                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;
+                default:
+                        fatal("buffer_uncompress: inflate returned %d", status);
+                        /* NOTREACHED */
+                }
+        }
+}