--- /dev/null
+/* Copyright (c) 2012 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "buffer.h"
+#include "base64.h"
+#include "istream-private.h"
+#include "istream-base64.h"
+
+struct base64_decoder_istream {
+ struct istream_private istream;
+};
+
+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(stream->parent);
+ if (ret <= 0) {
+ stream->istream.stream_errno = stream->parent->stream_errno;
+ stream->istream.eof = stream->parent->eof;
+ 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, buffer_avail, pos;
+ buffer_t buf;
+
+ data = i_stream_get_data(stream->parent, &size);
+ if (size == 0)
+ return 0;
+
+ i_stream_try_alloc(stream, (size+3)/4*3, &avail);
+ buffer_avail = stream->buffer_size - stream->pos;
+
+ if ((size + 3) / 4 * 3 > buffer_avail) {
+ /* can't fit everything to destination buffer.
+ write as much as we can. */
+ size = (buffer_avail / 3) * 4;
+ if (size == 0)
+ return -2;
+ }
+
+ buffer_create_data(&buf, stream->w_buffer + stream->pos, buffer_avail);
+ if (base64_decode(data, size, &pos, &buf) < 0) {
+ stream->istream.stream_errno = EINVAL;
+ return -1;
+ }
+
+ stream->pos += buf.used;
+ i_stream_skip(stream->parent, pos);
+ return pos > 0 ? 1 : 0;
+}
+
+static ssize_t i_stream_base64_decoder_read(struct istream_private *stream)
+{
+ struct base64_decoder_istream *bstream =
+ (struct base64_decoder_istream *)stream;
+ size_t pre_count, post_count;
+ int ret;
+
+ do {
+ ret = i_stream_read_parent(stream);
+ if (ret <= 0) {
+ if (ret < 0 && stream->istream.stream_errno == 0 &&
+ i_stream_get_data_size(stream->parent) > 0) {
+ /* base64 input with a partial block */
+ stream->istream.stream_errno = EINVAL;
+ }
+ return ret;
+ }
+
+ /* 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);
+
+ if (ret < 0)
+ 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)
+{
+ 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);
+ }
+ i_stream_default_seek_nonseekable(stream, v_offset, mark);
+}
+
+struct istream *
+i_stream_create_base64_decoder(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;
+ return i_stream_create(&bstream->istream, input,
+ i_stream_get_fd(input));
+}
--- /dev/null
+/* Copyright (c) 2010-2012 Dovecot authors, see the included COPYING file */
+
+#include "test-lib.h"
+#include "str.h"
+#include "istream-private.h"
+#include "istream-base64.h"
+
+struct {
+ const char *input;
+ const char *output;
+} tests[] = {
+ { "aGVsbG8gd29ybGQ=", "hello world" },
+ { "\naGVs\nbG8g\nd29y\nbGQ=\n", "hello world" },
+ { " aGVs \r\n bG8g \r\n d29y \t \r\n bGQ= \r\n\r\n", "hello world" },
+};
+
+static void
+decode_test(const char *base64_input, const char *output, bool broken_input)
+{
+ unsigned int base64_input_len = strlen(base64_input);
+ struct istream *input_data, *input;
+ const unsigned char *data;
+ size_t i, size;
+ int ret = 0;
+
+ input_data = test_istream_create_data(base64_input, base64_input_len);
+ test_istream_set_allow_eof(input_data, FALSE);
+ input = i_stream_create_base64_decoder(input_data);
+
+ for (i = 1; i <= base64_input_len; i++) {
+ test_istream_set_size(input_data, i);
+ while ((ret = i_stream_read(input)) > 0) ;
+ if (ret == -1 && broken_input)
+ break;
+ test_assert(ret == 0);
+ }
+ if (ret == 0) {
+ test_istream_set_allow_eof(input_data, TRUE);
+ while ((ret = i_stream_read(input)) > 0) ;
+ }
+ test_assert(ret == -1);
+ test_assert((input->stream_errno == 0 && !broken_input) ||
+ (input->stream_errno == EINVAL && broken_input));
+
+ data = i_stream_get_data(input, &size);
+ test_assert(size == strlen(output) && memcmp(data, output, size) == 0);
+ i_stream_unref(&input);
+ i_stream_unref(&input_data);
+}
+
+void test_istream_base64_decoder(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < N_ELEMENTS(tests); i++) {
+ test_begin(t_strdup_printf("istream base64 decoder %u", i+1));
+ decode_test(tests[i].input, tests[i].output, FALSE);
+ test_end();
+ }
+ test_begin("istream base64 decoder error");
+ decode_test("foo", "", TRUE);
+ decode_test("Zm9vC", "foo", TRUE);
+ decode_test("Zm9v!", "foo", TRUE);
+ decode_test("Zm9!v", "", TRUE);
+ decode_test("Zm9 v", "", TRUE);
+ decode_test("Zm 9v", "", TRUE);
+ decode_test("Z m9v", "", TRUE);
+ test_end();
+}
projects / thirdparty / dovecot / core.git / commitdiff
