diff --git a/compress/cstream.c b/compress/cstream.c
index 776d34e..d104bdb 100644
--- a/compress/cstream.c
+++ b/compress/cstream.c
@@ -62,6 +62,12 @@ enum b_status b_cstream_close(struct b_cstream *stream)
 	return B_SUCCESS;
 }
 
+static enum b_status read_cursor(
+	struct b_cstream *stream, void *buf, size_t count, size_t *out_nr_read)
+{
+	return b_stream_read_bytes(stream->s_endpoint, buf, count, out_nr_read);
+}
+
 static enum b_status read_uncompressed(
 	struct b_cstream *stream, void *buf, size_t count, size_t *out_nr_read)
 {
@@ -185,6 +191,10 @@ enum b_status b_cstream_read(
 		return B_ERR_BAD_STATE;
 	}
 
+	if (stream->s_flags & CSTREAM_CURSOR_MOVED) {
+		return read_cursor(stream, buf, count, out_nr_read);
+	}
+
 	if (stream->s_compression_depth == 0) {
 		return read_uncompressed(stream, buf, count, out_nr_read);
 	}
@@ -239,6 +249,12 @@ enum b_status b_cstream_read(
 	return status;
 }
 
+static enum b_status write_cursor(
+	struct b_cstream *stream, const void *buf, size_t count, size_t *nr_written)
+{
+	return b_stream_write_bytes(stream->s_endpoint, buf, count, nr_written);
+}
+
 static enum b_status write_uncompressed(
 	struct b_cstream *stream, const void *buf, size_t count, size_t *nr_written)
 {
@@ -310,6 +326,10 @@ enum b_status b_cstream_write(
 		return B_ERR_BAD_STATE;
 	}
 
+	if (stream->s_flags & CSTREAM_CURSOR_MOVED) {
+		return write_cursor(stream, buf, count, out_nr_written);
+	}
+
 	if (stream->s_compression_depth == 0) {
 		return write_uncompressed(stream, buf, count, out_nr_written);
 	}
@@ -366,6 +386,10 @@ enum b_status b_cstream_write(
 enum b_status b_cstream_begin_compressed_section(
 	struct b_cstream *stream, size_t *tx_uncompressed_bytes)
 {
+	if (stream->s_flags & CSTREAM_CURSOR_MOVED) {
+		return B_ERR_BAD_STATE;
+	}
+
 	if (tx_uncompressed_bytes) {
 		*tx_uncompressed_bytes = stream->s_tx_uncompressed_bytes;
 	}
@@ -387,6 +411,10 @@ enum b_status b_cstream_end_compressed_section(
 	struct b_cstream *stream, size_t *tx_compressed_bytes,
 	size_t *tx_uncompressed_bytes)
 {
+	if (stream->s_flags & CSTREAM_CURSOR_MOVED) {
+		return B_ERR_BAD_STATE;
+	}
+
 	tx_compressed_bytes
 		&& (*tx_compressed_bytes = stream->s_tx_compressed_bytes);
 
@@ -442,3 +470,46 @@ enum b_status b_cstream_end_compressed_section(
 
 	return flush_output_buffer(stream);
 }
+
+enum b_status b_cstream_set_cursor_position(struct b_cstream *stream, size_t pos)
+{
+	if (stream->s_compression_depth > 0) {
+		return B_ERR_BAD_STATE;
+	}
+
+	if (stream->s_flags & CSTREAM_CURSOR_MOVED) {
+		return B_ERR_BAD_STATE;
+	}
+
+	stream->s_cursor = b_stream_cursor(stream->s_endpoint);
+
+	enum b_status status
+		= b_stream_seek(stream->s_endpoint, pos, B_STREAM_SEEK_START);
+	if (!B_OK(status)) {
+		stream->s_cursor = 0;
+		return status;
+	}
+
+	stream->s_flags |= CSTREAM_CURSOR_MOVED;
+
+	return B_SUCCESS;
+}
+
+enum b_status b_cstream_restore_cursor_position(struct b_cstream *stream)
+{
+	if (!(stream->s_flags & CSTREAM_CURSOR_MOVED)) {
+		return B_ERR_BAD_STATE;
+	}
+
+	enum b_status status = b_stream_seek(
+		stream->s_endpoint, stream->s_cursor, B_STREAM_SEEK_START);
+	stream->s_cursor = 0;
+
+	if (!B_OK(status)) {
+		return status;
+	}
+
+	stream->s_flags &= ~CSTREAM_CURSOR_MOVED;
+
+	return B_SUCCESS;
+}
diff --git a/compress/cstream.h b/compress/cstream.h
index a40127d..90cc46a 100644
--- a/compress/cstream.h
+++ b/compress/cstream.h
@@ -8,7 +8,12 @@
 struct b_stream;
 struct b_compressor;
 
+enum cstream_flags {
+	CSTREAM_CURSOR_MOVED = 0x01u,
+};
+
 struct b_cstream {
+	enum cstream_flags s_flags;
 	struct b_stream *s_endpoint;
 	struct b_compressor *s_compressor;
 	/* s_in is the input buffer, and s_out is the output buffer.
@@ -55,6 +60,10 @@ struct b_cstream {
 	 * b_cstream_read
 	 */
 	size_t s_tx_uncompressed_bytes;
+
+	/* when the endpoint cursor is moved, the previous cursor position is
+	 * saved here so it can be restored later */
+	size_t s_cursor;
 };
 
 #endif
diff --git a/compress/include/blue/compress/cstream.h b/compress/include/blue/compress/cstream.h
index cdffc80..270468c 100644
--- a/compress/include/blue/compress/cstream.h
+++ b/compress/include/blue/compress/cstream.h
@@ -22,4 +22,7 @@ BLUE_API b_status b_cstream_end_compressed_section(
 	b_cstream *stream, size_t *tx_compressed_bytes,
 	size_t *tx_uncompressed_bytes);
 
+BLUE_API b_status b_cstream_set_cursor_position(b_cstream *stream, size_t pos);
+BLUE_API b_status b_cstream_restore_cursor_position(b_cstream *stream);
+
 #endif