X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/177f020f122827214159c46dcfe7ded1e3c8d1c3..c576ad2674c37a1c63f004c71049998f38854c64:/sbr/base64.c

diff --git a/sbr/base64.c b/sbr/base64.c
index 00b9c2fe..cbd225de 100644
--- a/sbr/base64.c
+++ b/sbr/base64.c
@@ -13,6 +13,17 @@
 static const char nib2b64[0x40+1] =
 	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
+/*
+ * Copy data from one file to another, converting to base64-encoding.
+ *
+ * Arguments include:
+ *
+ * in		- Input filehandle (unencoded data)
+ * out		- Output filename (base64-encoded data)
+ * crlf		- If set, output encoded CRLF for every LF on input.
+ *
+ * Returns OK on success, NOTOK otherwise.
+ */
 int
 writeBase64aux (FILE *in, FILE *out, int crlf)
 {
@@ -123,17 +134,16 @@ writeBase64 (const unsigned char *in, size_t length, unsigned char *out)
 	for (cc = 0; length > 0 && cc < 3; ++cc, --length)
           /* empty */ ;
 
-	if (cc == 0) {
+	if (cc == 0)
 	    break;
-	} else {
-	    bits = (in[0] & 0xff) << 16;
-	    if (cc > 1) {
-		bits |= (in[1] & 0xff) << 8;
-		if (cc > 2) {
-		    bits |= in[2] & 0xff;
-		}
-	    }
-	}
+
+        bits = (in[0] & 0xff) << 16;
+        if (cc > 1) {
+            bits |= (in[1] & 0xff) << 8;
+            if (cc > 2) {
+                bits |= in[2] & 0xff;
+            }
+        }
 
 	for (bp = out + 4; bp > out; bits >>= 6)
 	    *--bp = nib2b64[bits & 0x3f];
@@ -176,17 +186,16 @@ writeBase64raw (const unsigned char *in, size_t length, unsigned char *out)
 	for (cc = 0; length > 0 && cc < 3; ++cc, --length)
           /* empty */ ;
 
-	if (cc == 0) {
+	if (cc == 0)
 	    break;
-	} else {
-	    bits = (in[0] & 0xff) << 16;
-	    if (cc > 1) {
-		bits |= (in[1] & 0xff) << 8;
-		if (cc > 2) {
-		    bits |= in[2] & 0xff;
-		}
-	    }
-	}
+
+        bits = (in[0] & 0xff) << 16;
+        if (cc > 1) {
+            bits |= (in[1] & 0xff) << 8;
+            if (cc > 2) {
+                bits |= in[2] & 0xff;
+            }
+        }
 
 	for (bp = out + 4; bp > out; bits >>= 6)
 	    *--bp = nib2b64[bits & 0x3f];
@@ -229,7 +238,13 @@ static const unsigned char b642nib[0x80] = {
 
 /*
  * Decode a base64 string.  The result, decoded, must be freed by the caller.
- * See description of arguments with declaration in h/prototypes.h.
+ *
+ * encoded      - the string to be decoded
+ * decoded      - the decoded bytes
+ * len          - number of decoded bytes
+ * skip-crs     - non-zero for text content, and for which CR's should be
+ *                skipped
+ * digest       - for an MD5 digest, it can be null
  */
 int
 decodeBase64 (const char *encoded, unsigned char **decoded, size_t *len,
@@ -259,7 +274,8 @@ decodeBase64 (const char *encoded, unsigned char **decoded, size_t *len,
                 }
                 if (skip  ||  (((unsigned char) *cp) & 0x80)  ||
                     (value = b642nib[((unsigned char) *cp) & 0x7f]) > 0x3f) {
-                    inform("invalid BASE64 encoding in %s", cp);
+                    inform("invalid base64 byte %#x: %.42s",
+                        *(unsigned char *)cp, cp);
                     charstring_free (decoded_c);
                     *decoded = NULL;
 
@@ -300,22 +316,17 @@ test_end:
                 break;
 
             case '=':
-                if (++skip > 3) {
-                    self_delimiting = 1;
-                    break;
-                } else {
+                if (++skip <= 3)
                     goto test_end;
-                }
+                self_delimiting = 1;
+                break;
         }
     }
 
     if (! self_delimiting  &&  bitno != 18) {
-        int i;
-
         /* Show some context for the error. */
-        for (i = 0; i < 20  &&  cp > encoded; ++i, --cp) {}
-        inform("premature ending (bitno %d) near %s", bitno,
-                cp ? cp : encoded);
+        cp -= min(cp - encoded, 20);
+        inform("premature ending (bitno %d) near %s", bitno, cp);
         charstring_free (decoded_c);
         *decoded = NULL;