Rewrite base64 processing loop, and handle errors.

diff --git a/base64.c b/base64.c
index 425229249a07964c5b29ee65026d6eb6b5889d51..c428d6bd7824c470822803ed1f0ebeb89c332476 100644 (file)
--- 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;