X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=base64.c;h=a8c7f1c156182f6dfde33a93f0d059bf8ed4ff7e;hb=d88fabcc5f6991c32c9d995b3ef271b87d1491f8;hp=1dc533dd003d1b89d12d49bbd151626785d1beaa;hpb=3d58a7d4e185fdd98cad23b8896cddfab0de594c;p=~andy%2Ffetchmail

diff --git a/base64.c b/base64.c
index 1dc533dd..a8c7f1c1 100644
--- a/base64.c
+++ b/base64.c
@@ -52,8 +52,9 @@ void to64frombits(unsigned char *out, const unsigned char *in, int inlen)
     *out = '\0';
 }
 
-int from64tobits(char *out, const char *in)
+int from64tobits(char *out, const char *in, int maxlen)
 /* base 64 to raw bytes in quasi-big-endian order, returning count of bytes */
+/* maxlen limits output buffer size, set to zero to ignore */
 {
     int len = 0;
     register unsigned char digit1, digit2, digit3, digit4;
@@ -77,16 +78,22 @@ int from64tobits(char *out, const char *in)
 	if (digit4 != '=' && DECODE64(digit4) == BAD)
 	    return(-1);
 	in += 4;
-	*out++ = (DECODE64(digit1) << 2) | (DECODE64(digit2) >> 4);
 	++len;
+	if (maxlen && len > maxlen)
+	    return(-1);
+	*out++ = (DECODE64(digit1) << 2) | (DECODE64(digit2) >> 4);
 	if (digit3 != '=')
 	{
-	    *out++ = ((DECODE64(digit2) << 4) & 0xf0) | (DECODE64(digit3) >> 2);
 	    ++len;
+	    if (maxlen && len > maxlen)
+	        return(-1);
+	    *out++ = ((DECODE64(digit2) << 4) & 0xf0) | (DECODE64(digit3) >> 2);
 	    if (digit4 != '=')
 	    {
+	        ++len;
+		if (maxlen && len > maxlen)
+		    return(-1);
 		*out++ = ((DECODE64(digit3) << 6) & 0xc0) | DECODE64(digit4);
-		++len;
 	    }
 	}
     } while