Thread

Re: encode/decode support for base64url

David E. Wheeler <david@justatheory.com> — 2025-07-10T20:55:15Z

On Jul 10, 2025, at 16:38, Florents Tselai <florents.tselai@gmail.com> wrote:

> Why isn’t this sufficient? 
> 
> static uint64
> pg_base64_encode_internal(const char *src, size_t len, char *dst, bool url)
> {
> const char *alphabet = url ? _base64url : _base64;

Ah, it is. I hadn’t got that far. I was tripped up to see this in your patch:

```patch
+static uint64
+pg_base64url_encode(const char *src, size_t len, char *dst)
+{
+	uint64 encoded_len;
+	if (len == 0)
+		return 0;
+
+	encoded_len = pg_base64_encode(src, len, dst);
+
+	/* Convert Base64 to Base64URL */
+	for (uint64 i = 0; i < encoded_len; i++) {
+		if (dst[i] == '+')
+			dst[i] = '-';
+		else if (dst[i] == '/')
+			dst[i] = '_';
+	}
+
+	/* Trim '=' padding */
+	while (encoded_len > 0 && dst[encoded_len - 1] == '=')
+		encoded_len--;
+
+	return encoded_len;
+}
```

I didn’t realize it was a set of patches for stuff you did and then later undid. Could you flatten the patch into just what’s changed at the end?

Best,

David