Corrected a bug in the wrap-around carry (found bug by comparing test results

with another implementation).

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@7141 dc483132-0cff-0310-8789-dd5450dbe970

diff --git a/src/lib/crypto/des/u_nfold.c b/src/lib/crypto/des/u_nfold.c
index 4311b91850a037fac1e4b3929caf69f87025b953..63eb0e29a715ffddbaff099c42bcbb5c48a53f7d 100644 (file)
--- a/src/lib/crypto/des/u_nfold.c
+++ b/src/lib/crypto/des/u_nfold.c
@@ -66,40 +66,32 @@ mit_des_n_fold(inbuf, inlen, outbuf, outlen)
 #endif
 
     do {
-       int i, j;
+       int j;
        register unsigned int k;
 
-       if ((bytes % inlen) == 0) {
-           /* Rotate input */
-           k = ((bytes/inlen) * ROTATE_VALUE) % (inlen*8);
-           
-           for (j = (k+7)/8; j < inlen + (k+7)/8; j++)
-               tempbuf[j % inlen] =
-                   ((inbuf[((8*j-k)/8)%inlen] << ((8-(k&7))&7)) +
-                    ((k&7) ? (inbuf[((8*j-k)/8 +1)%inlen] >> (k&7)) : 0))
-                   & 0xff;
-       }
-
+       /* Rotate input */
+       k = ((bytes/inlen) * ROTATE_VALUE) % (inlen*8);
+       for (j = (k+7)/8; j < inlen + (k+7)/8; j++)
+           tempbuf[j % inlen] =
+               ((inbuf[((8*j-k)/8)%inlen] << ((8-(k&7))&7)) +
+                ((k&7) ? (inbuf[((8*j-k)/8 +1)%inlen] >> (k&7)) : 0))
+               & 0xff;
 
-       i = min(outlen - (bytes % outlen), inlen - (bytes % inlen));
-
-       j = i;
-       k = 0;
-       while (j--) {
-           k += outbuf[(bytes+j) % outlen] + tempbuf[(bytes+j) % inlen];
+       for (k=0, j=inlen; j--; ) {
+           k += outbuf[(bytes+j) % outlen] + tempbuf[j];
            outbuf[(bytes+j) % outlen] = k & 0xff;
            k >>= 8;
        }
-
-       j = outlen-1;
+       j = bytes % outlen;
        while (k) {
+           if (j-- == 0)
+               j += outlen;
            k += outbuf[j];
-           outbuf[j--] = k & 0xff;
+           outbuf[j] = k & 0xff;
            k >>= 8;
        }
-       
-       bytes += i;
-    } while (((bytes % inlen) != 0) || ((bytes % outlen) != 0));
+       bytes += inlen;
+    } while (bytes % outlen);
     
     return 0;
 }