[hackers] [sbase] uudecode: fix flushing (again) through rewrite || Tai Chi Minh Ralph Eastwood

From: <git_AT_suckless.org>
Date: Tue, 24 Mar 2015 23:53:47 +0100 (CET)

commit b64b51dc9178f55d9ec5dec8ccf3008fb8e22af5
Author: Tai Chi Minh Ralph Eastwood <tcmreastwood_AT_gmail.com>
Date: Wed Feb 11 13:27:41 2015 +0000

    uudecode: fix flushing (again) through rewrite

diff --git a/uudecode.c b/uudecode.c
index 947a846..305b521 100644
--- a/uudecode.c
+++ b/uudecode.c
_AT_@ -162,34 +162,49 @@ uudecodeb64(FILE *fp, FILE *outfp)
         char bufb[60], *pb;
         char out[45], *po;
         size_t n;
- int b = 0, e, t = 0;
+ int b = 0, e, t = -1, l = 1;
         unsigned char b24[3] = {0, 0, 0};
 
         while ((n = fread(bufb, 1, sizeof(bufb), fp))) {
                 for (pb = bufb, po = out; pb < bufb + n; pb++) {
- if (*pb == '=') {
- if (b == 0 || t) {
- /* footer size is ==== is 4 */
- if (++t < 4)
+ if (*pb == '\n') {
+ l++;
+ continue;
+ } else if (*pb == '=') {
+ switch (b) {
+ case 0:
+ /* expected '=' remaining
+ * including footer */
+ if (--t) {
+ fwrite(out, 1,
+ (po - out),
+ outfp);
+ return;
+ }
+ continue;
+ case 1:
+ eprintf("%d: unexpected \"=\""
+ "appeared.", l);
+ case 3:
+ *po++ = b24[0];
+ *po++ = b24[1];
+ b = 0;
+ t = 6; /* expect 6 '=' */
+ continue;
+ case 2:
+ *po++ = b24[0];
+ b = 0;
+ t = 5; /* expect 5 '=' */
                                                 continue;
- else
- goto flush;
- } else if (b == 1) {
- eprintf("unexpected \"=\" appeared.");
- } else if (b == 2) {
- *po++ = b24[0];
- goto flush;
- } else if (b == 3) {
- *po++ = b24[0];
- *po++ = b24[1];
- goto flush;
                                 }
- }
- if ((e = b64dt[(int)*pb]) == -1) {
- eprintf("invalid byte \"%c\"", *pb);
- } else if (e == -2) /* whitespace */
+ } else if ((e = b64dt[(int)*pb]) == -1)
+ eprintf("%d: invalid byte \"%c\"", l, *pb);
+ else if (e == -2) /* whitespace */
                                 continue;
- switch (b) {
+ else if (t > 0) /* state is parsing pad/footer */
+ eprintf("%d: invalid byte \"%c\" after padding",
+ l, *pb);
+ switch (b) { /* decode next base64 chr based on state */
                                 case 0: b24[0] |= e << 2; break;
                                 case 1: b24[0] |= (e >> 4) & 0x3;
                                         b24[1] |= (e & 0xf) << 4; break;
_AT_@ -197,7 +212,7 @@ uudecodeb64(FILE *fp, FILE *outfp)
                                         b24[2] |= (e & 0x3) << 6; break;
                                 case 3: b24[2] |= e; break;
                         }
- if (++b == 4) {
+ if (++b == 4) { /* complete decoding an octet */
                                 *po++ = b24[0];
                                 *po++ = b24[1];
                                 *po++ = b24[2];
_AT_@ -205,11 +220,9 @@ uudecodeb64(FILE *fp, FILE *outfp)
                                 b = 0;
                         }
                 }
- goto flush;
+ fwrite(out, 1, (po - out), outfp);
         }
- eprintf("invalid uudecode footer \"====\" not found\n");
-flush:
- fwrite(out, 1, (po - out), outfp);
+ eprintf("%d: invalid uudecode footer \"====\" not found\n", l);
 }
 
 static void
Received on Tue Mar 24 2015 - 23:53:47 CET