Adding upstream version 1:2.3.21+dfsg1.upstream/1%2.3.21+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/src/lib/istream-base64-decoder.c b/src/lib/istream-base64-decoder.c
new file mode 100644
index 0000000..6eaa842
--- /dev/null
+++ b/src/lib/istream-base64-decoder.c
@@ -0,0 +1,171 @@
+/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "buffer.h"
+#include "base64.h"
+#include "hex-binary.h"
+#include "istream-private.h"
+#include "istream-base64.h"
+
+struct base64_decoder_istream {
+	struct istream_private istream;
+
+	struct base64_decoder decoder;
+};
+
+static int i_stream_read_parent(struct istream_private *stream)
+{
+	size_t size;
+	ssize_t ret;
+
+	size = i_stream_get_data_size(stream->parent);
+	if (size >= 4)
+		return 1;
+
+	/* we have less than one base64 block.
+	   see if there is more data available. */
+	ret = i_stream_read_memarea(stream->parent);
+	if (ret <= 0) {
+		stream->istream.stream_errno = stream->parent->stream_errno;
+		return ret;
+	}
+	size = i_stream_get_data_size(stream->parent);
+	i_assert(size != 0);
+	return 1;
+}
+
+static int
+i_stream_base64_try_decode_block(struct base64_decoder_istream *bstream)
+{
+	struct istream_private *stream = &bstream->istream;
+	const unsigned char *data;
+	size_t size, avail, pos;
+	buffer_t buf;
+
+	data = i_stream_get_data(stream->parent, &size);
+	if (size == 0)
+		return 0;
+
+	if (!i_stream_try_alloc(stream, (size+3)/4*3, &avail))
+		return -2;
+
+	buffer_create_from_data(&buf, stream->w_buffer + stream->pos, avail);
+	if (base64_decode_more(&bstream->decoder, data, size, &pos, &buf) < 0) {
+		io_stream_set_error(&stream->iostream,
+			"Invalid base64 data: 0x%s",
+			binary_to_hex(data+pos, I_MIN(size-pos, 8)));
+		stream->istream.stream_errno = EINVAL;
+		return -1;
+	}
+
+	stream->pos += buf.used;
+	i_stream_skip(stream->parent, pos);
+	return pos > 0 ? 1 : 0;
+}
+
+static void
+i_stream_base64_finish_decode(struct base64_decoder_istream *bstream)
+{
+	struct istream_private *stream = &bstream->istream;
+
+	i_assert(i_stream_get_data_size(stream->parent) ==  0);
+
+	if (base64_decode_finish(&bstream->decoder) < 0) {
+		io_stream_set_error(&stream->iostream,
+			"Base64 data ends prematurely");
+		stream->istream.stream_errno = EPIPE;
+	}
+}
+
+static ssize_t i_stream_base64_decoder_read(struct istream_private *stream)
+{
+	struct base64_decoder_istream *bstream =
+		container_of(stream, struct base64_decoder_istream, istream);
+	size_t pre_count, post_count;
+	int ret;
+
+	if (base64_decode_is_finished(&bstream->decoder)) {
+		stream->istream.eof = TRUE;
+		return -1;
+	}
+
+	do {
+		ret = i_stream_read_parent(stream);
+		if (ret == 0)
+			return 0;
+		if (ret < 0 && ret != -2) {
+			if (stream->istream.stream_errno != 0)
+				return -1;
+			if (i_stream_get_data_size(stream->parent) == 0) {
+				i_stream_base64_finish_decode(bstream);
+				stream->istream.eof = TRUE;
+				return -1;
+			}
+		}
+
+		/* encode as many blocks as fits into destination buffer */
+		pre_count = stream->pos - stream->skip;
+		while ((ret = i_stream_base64_try_decode_block(bstream)) > 0) ;
+		post_count = stream->pos - stream->skip;
+	} while (ret == 0 && pre_count == post_count);
+
+	if (ret < 0 && pre_count == post_count)
+		return ret;
+
+	i_assert(post_count > pre_count);
+	return post_count - pre_count;
+}
+
+static void
+i_stream_base64_decoder_seek(struct istream_private *stream,
+			     uoff_t v_offset, bool mark)
+{
+	struct base64_decoder_istream *bstream =
+		container_of(stream, struct base64_decoder_istream, istream);
+
+	if (v_offset < stream->istream.v_offset) {
+		/* seeking backwards - go back to beginning and seek
+		   forward from there. */
+		stream->parent_expected_offset = stream->parent_start_offset;
+		stream->skip = stream->pos = 0;
+		stream->istream.v_offset = 0;
+		i_stream_seek(stream->parent, 0);
+
+		base64_decode_reset(&bstream->decoder);
+	}
+	i_stream_default_seek_nonseekable(stream, v_offset, mark);
+}
+
+static struct istream *
+i_stream_create_base64_decoder_common(const struct base64_scheme *b64,
+				      struct istream *input)
+{
+	struct base64_decoder_istream *bstream;
+
+	bstream = i_new(struct base64_decoder_istream, 1);
+	bstream->istream.max_buffer_size = input->real_stream->max_buffer_size;
+
+	bstream->istream.read = i_stream_base64_decoder_read;
+	bstream->istream.seek = i_stream_base64_decoder_seek;
+
+	bstream->istream.istream.readable_fd = FALSE;
+	bstream->istream.istream.blocking = input->blocking;
+	bstream->istream.istream.seekable = input->seekable;
+
+	base64_decode_init(&bstream->decoder, b64, 0);
+
+	return i_stream_create(&bstream->istream, input,
+			       i_stream_get_fd(input), 0);
+}
+
+struct istream *
+i_stream_create_base64_decoder(struct istream *input)
+{
+	return i_stream_create_base64_decoder_common(&base64_scheme, input);
+}
+
+struct istream *
+i_stream_create_base64url_decoder(struct istream *input)
+{
+	return i_stream_create_base64_decoder_common(&base64url_scheme, input);
+}