lws_b64_decode_string error "base64 must end at end of input"

[Vmcsnekke]

lws_b64_decode_string always fails, see:

[2025/02/17 17:29:31:9128] E: _lws_b64_decode_string: base64 must end at end of input

I looked into it and fixed it (see below a patch). Is there a guide on howto send this upstream?

The external lws_b64_decode_string and internal _lws_b64_decode_string
do not require an input string length, and this is when strlen is used
to get the length and compare it against the
"length-of-the-input-actually-decoded".
The comparison forgets no input string length might be given and so
_lws_b64_decode_string might fail with "base64 must end at end of input".

This can be easily fixed by using strlen right away to pass the
input string length to _lws_b64_decode_string.
---
 lib/misc/base64-decode.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/lib/misc/base64-decode.c b/lib/misc/base64-decode.c
index 8f0a735d..332325cc 100644
--- a/lib/misc/base64-decode.c
+++ b/lib/misc/base64-decode.c
@@ -203,8 +203,7 @@ lws_b64_decode_stateful(struct lws_b64state *s, const char *in, size_t *in_len,
  * returns length of decoded string in out, or -1 if out was too small
  * according to out_size
  *
- * Only reads up to in_len chars, otherwise if in_len is -1 on entry reads until
- * the first NUL in the input.
+ * Only reads up to in_len chars.
  */
 
 static size_t
@@ -213,9 +212,6 @@ _lws_b64_decode_string(const char *in, int in_len, char *out, size_t out_size)
        struct lws_b64state state;
        size_t il = (size_t)in_len, ol = out_size;
 
-       if (in_len == -1)
-               il = strlen(in);
-
        lws_b64_decode_state_init(&state);
        if (lws_b64_decode_stateful(&state, in, &il, (uint8_t *)out, &ol, 1) < 0)
                /* pass on the failure */
@@ -229,10 +225,15 @@ _lws_b64_decode_string(const char *in, int in_len, char *out, size_t out_size)
        return ol;
 }
 
+
+/*
+ * reads until the first NUL in the input.
+ */
+
 int
 lws_b64_decode_string(const char *in, char *out, int out_size)
 {
-       return (int)_lws_b64_decode_string(in, -1, out, (unsigned int)out_size);
+       return (int)_lws_b64_decode_string(in, (int)strlen(in), out, (unsigned int)out_size);
 }
 
 int
-- 
2.47.1