From: chris mikkelson <chris@mikk.net>
Date: Fri, 12 Mar 2010 22:18:01 +0000 (-0600)
Subject: Rewrite base64 processing loop, and handle errors.
X-Git-Url: https://git.mikk.net/?a=commitdiff_plain;h=6211099e6bd4b5799422fa2f1078d17704fb0a4b;p=liburl

Rewrite base64 processing loop, and handle errors.
---

diff --git a/base64.c b/base64.c
index 4252292..c428d6b 100644
--- a/base64.c
+++ b/base64.c
@@ -32,6 +32,7 @@ base64_init(void)
 struct b64_state {
 	unsigned u;
 	int v;
+	int error;
 };
 
 static struct b64_state *
@@ -54,22 +55,19 @@ b64_decode(struct b64_state *b64s, char *s, int len,
 	char *p;
 	unsigned u, v;
 	int l;
-	*outlen = 0;
 
-	l = 0;
+	*outlen = 0;
 	u = b64s->u;
 	v = b64s->v;
-	b64s->u = b64s->v = 0;
 
 	for (p = s; p < s + len;) {
-		if (*p == '\r' || *p == '\n') continue;
-		if (size < 3) return (int)(p - s);
+		if (*p == '\r' || *p == '\n') {
+			p++;
+			continue;
+		}
+		if (size < 3) goto done;
 		for (; v < 4; v++) {
-			if (p == s + len) {
-				b64s->u = u;
-				b64s->v = v;
-				return len;
-			}
+			if (p >= s + len) goto done;
 			l = i64[(unsigned int)*p++];
 			if (l < 0) return -1;
 			u <<= 6;
@@ -88,6 +86,8 @@ b64_decode(struct b64_state *b64s, char *s, int len,
 		}
 		v = 0;
 	}
+done:	b64s->v = v;
+	b64s->u = u;
 	return p - s;
 }
 
@@ -129,11 +129,12 @@ base64_process(msgproc *m, char *buf, size_t len)
 	struct b64_state *b64s = (struct b64_state *)msgproc_getpriv(m);
 	msgproc *next = msgproc_next(m);
 
+	if (b64s->error) return;
 	while (len > 0) {
 		ret = b64_decode(b64s, buf, len, tmp, sizeof(tmp), &tmplen);
 		if (ret < 1) {
-			/* TODO: handle errors in *b64s; skip all
-				text after error, or recover? */
+			b64s->error = 1;
+			break;
 		}
 		msgproc_process(next, tmp, tmplen);
 		buf += ret; len -= ret;