lib: base64 - Truly fix dest buffer assertion in base64_decode_more().

Previous fix was inadequate in the presence of padding at the end of input.

diff --git a/src/lib/base64.c b/src/lib/base64.c
index fb6cd635e62d265d8fd5c0aebbbff1232f7f4474..f0baf6578bab4cee64d55d1bd362f2a05636efba 100644 (file)
--- a/src/lib/base64.c
+++ b/src/lib/base64.c
@@ -561,6 +561,12 @@ int base64_decode_more(struct base64_decoder *dec,
                        continue;
                }
 
+               if (dst_avail == 0) {
+                       i_assert(src_pos_r != NULL);
+                       *src_pos_r = src_pos;
+                       return 1;
+               }
+
                switch (dec->sub_pos) {
                case 0:
                        dec->buf = dm;
@@ -590,13 +596,6 @@ int base64_decode_more(struct base64_decoder *dec,
                default:
                        i_unreached();
                }
-               if (dst_avail == 0) {
-                       if (src_pos_r != NULL)
-                               *src_pos_r = src_pos + 1;
-                       else
-                               i_assert(src_pos + 1 == src_size);
-                       return 1;
-               }
        }
 
        if (dec->seen_padding) {

diff --git a/src/lib/test-base64.c b/src/lib/test-base64.c
index 534d23139a49ee775128684802f02904943075a5..5b9b38224d6935e6197d6c1d49162610c41c0c56 100644 (file)
--- a/src/lib/test-base64.c
+++ b/src/lib/test-base64.c
@@ -834,18 +834,27 @@ test_base64_random_lowlevel_one_block(const struct base64_scheme *b64,
 {
        struct base64_encoder enc;
        struct base64_decoder dec;
+       void *space;
+       size_t enc_size;
+       buffer_t buf;
        int ret;
 
        buffer_set_used_size(buf1, 0);
        buffer_set_used_size(buf2, 0);
 
        base64_encode_init(&enc, b64, enc_flags, max_line_len);
-       base64_encode_more(&enc, in_buf, in_buf_size, NULL, buf1);
-       base64_encode_finish(&enc, buf1);
+       enc_size = base64_get_full_encoded_size(&enc, in_buf_size);
+       space = buffer_append_space_unsafe(buf1, enc_size);
+       buffer_create_from_data(&buf, space, enc_size);
+
+       base64_encode_more(&enc, in_buf, in_buf_size, NULL, &buf);
+       base64_encode_finish(&enc, &buf);
 
        base64_decode_init(&dec, b64, dec_flags);
-       ret = base64_decode_more(&dec, buf1->data, buf1->used,
-                                NULL, buf2);
+       space = buffer_append_space_unsafe(buf2, in_buf_size);
+       buffer_create_from_data(&buf, space, in_buf_size);
+
+       ret = base64_decode_more(&dec, buf1->data, buf1->used, NULL, &buf);
        if (ret >= 0)
                ret = base64_decode_finish(&dec);