fix base64_decode() for BASE64URLNOPAD

src/base64.c

@@ -189,14 +189,14 @@ base64_decode(const enum encoding dec, char *restrict const buf,
 	      const size_t maxlen, const char *restrict const p, va_list ap)
 {
 	struct b64_alphabet *alpha = &b64_alphabet[dec];
-	const char *s;
 	char *dest = buf;
 	unsigned u = 0, term = 0;
 	int n = 0;
 
 	AN(buf);
 
-	for (s = p; s != vrt_magic_string_end; s = va_arg(ap, const char *)) {
+	for (const char *s = p; s != vrt_magic_string_end;
+	     s = va_arg(ap, const char *)) {
 		if (s == NULL)
 			continue;
 		if (*s && term) {
@@ -229,11 +229,14 @@ base64_decode(const enum encoding dec, char *restrict const buf,
 			}
 		}
 	}
-	if (n)
+	if (n) {
+		if (!alpha->padding)
+			u <<= 6 * (4 - n);
 		if (decode(&dest, buf, maxlen, u, n-term) < 0) {
 			errno = ENOMEM;
 			return -1;
 		}
+	}
 
 	return dest - buf;
 }

src/tests/base64.vtc

@@ -68,6 +68,25 @@ varnish v1 -vcl+backend {
 			       + "H" + resp.http.mid2 + "kLw"
 			       + resp.http.pad));
 
+	    set resp.http.decnopad = convert.encode(IDENTITY,
+				     convert.decode(BASE64URLNOPAD,
+						    "L0hlbGxvIHdvcmxkLw"));
+
+	    set resp.http.decnopad2pieces
+	      = convert.encode(IDENTITY, convert.decode(BASE64URLNOPAD,
+			       resp.http.l + "0hlbGxvIHdvcmxkLw"));
+
+	    set resp.http.decnopad6pieces
+	      = convert.encode(IDENTITY, convert.decode(BASE64URLNOPAD,
+			       resp.http.l + "0hlb" + resp.http.mid1
+			       + "H" + resp.http.mid2 + "kLw"));
+
+	    set resp.http.decnopadlong
+	      = convert.encode(IDENTITY,
+		convert.decode(BASE64URLNOPAD,
+	        "VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSBsYXp5IGRvZw"
+			      ));
+
 	}
 } -start
 
@@ -86,6 +105,10 @@ client c1 {
 	expect resp.http.dec2pieces == "/Hello world/"
 	expect resp.http.dec3pieces == "/Hello world/"
 	expect resp.http.dec7pieces == "/Hello world/"
+	expect resp.http.decnopad == "/Hello world/"
+	expect resp.http.decnopad2pieces == "/Hello world/"
+	expect resp.http.decnopad6pieces == "/Hello world/"
+	expect resp.http.decnopadlong == "The quick brown fox jumps over the lazy dog"
 }
 
 client c1 -run