X-Git-Url: https://vcs.fsf.org/?a=blobdiff_plain;f=src%2Fsrc%2Fbase64.c;h=e63522ec4d5bc4a002bc8ca84fcd40a63339ddc4;hb=56cc2ec0010e6c917a8f1ba285c86e6dadb6f0d3;hp=ca6466bf22d4ed77f7c05ac15e5e3d3d87f136c1;hpb=3c51463e961cb96df8f624420f833c65505bb451;p=exim.git

diff --git a/src/src/base64.c b/src/src/base64.c
index ca6466bf2..e63522ec4 100644
--- a/src/src/base64.c
+++ b/src/src/base64.c
@@ -5,7 +5,7 @@
 /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004, 2015 */
 /* License: GPL */
 
-/* Copyright (c) University of Cambridge 1995 - 2015 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 
@@ -129,7 +129,7 @@ compact loop is messy and would probably run more slowly.
 Arguments:
   code        points to the coded string, zero-terminated
   ptr         where to put the pointer to the result, which is in
-              dynamic store, and zero-terminated
+              allocated store, and zero-terminated
 
 Returns:      the number of bytes in the result,
               or -1 if the input was malformed
@@ -150,12 +150,16 @@ static uschar dec64table[] = {
 };
 
 int
-b64decode(uschar *code, uschar **ptr)
+b64decode(const uschar *code, uschar **ptr)
 {
+
 int x, y;
-uschar *result = store_get(3*(Ustrlen(code)/4) + 1);
+uschar *result;
 
-*ptr = result;
+{
+  int l = Ustrlen(code);
+  *ptr = result = store_get(1 + l/4 * 3 + l%4);
+}
 
 /* Each cycle of the loop handles a quantum of 4 input bytes. For the last
 quantum this may decode to 1, 2, or 3 output bytes. */
@@ -163,35 +167,50 @@ quantum this may decode to 1, 2, or 3 output bytes. */
 while ((x = *code++) != 0)
   {
   if (isspace(x)) continue;
+  /* debug_printf("b64d: '%c'\n", x); */
 
   if (x > 127 || (x = dec64table[x]) == 255) return -1;
 
   while (isspace(y = *code++)) ;
-  if (y == 0 || (y = dec64table[y]) == 255)
+  /* debug_printf("b64d: '%c'\n", y); */
+  if (y > 127 || (y = dec64table[y]) == 255)
     return -1;
 
   *result++ = (x << 2) | (y >> 4);
+  /* debug_printf("b64d:      -> %02x\n", result[-1]); */
 
   while (isspace(x = *code++)) ;
-  if (x == '=')
+  /* debug_printf("b64d: '%c'\n", x); */
+  if (x == '=')		/* endmarker, but there should be another */
     {
     while (isspace(x = *code++)) ;
-    if (x != '=' || *code != 0) return -1;
+    /* debug_printf("b64d: '%c'\n", x); */
+    if (x != '=') return -1;
+    while (isspace(y = *code++)) ;
+    if (y != 0) return -1;
+    /* debug_printf("b64d: DONE\n"); */
+    break;
     }
   else
     {
     if (x > 127 || (x = dec64table[x]) == 255) return -1;
     *result++ = (y << 4) | (x >> 2);
+    /* debug_printf("b64d:      -> %02x\n", result[-1]); */
 
     while (isspace(y = *code++)) ;
+    /* debug_printf("b64d: '%c'\n", y); */
     if (y == '=')
       {
-      if (*code != 0) return -1;
+      while (isspace(y = *code++)) ;
+      if (y != 0) return -1;
+      /* debug_printf("b64d: DONE\n"); */
+      break;
       }
     else
       {
       if (y > 127 || (y = dec64table[y]) == 255) return -1;
       *result++ = (x << 6) | y;
+      /* debug_printf("b64d:      -> %02x\n", result[-1]); */
       }
     }
   }
@@ -201,23 +220,6 @@ return result - *ptr;
 }
 
 
-/*************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************
- *************************************************/
-
 /*************************************************
 *          Encode byte-string in base 64         *
 *************************************************/
@@ -247,7 +249,7 @@ uschar *p = code;
 
 while (len-- >0)
   {
-  register int x, y;
+  int x, y;
 
   x = *clear++;
   *p++ = enc64table[(x >> 2) & 63];