try to catch malicious input in textcode fmt_* functions

CHANGES

@@ -7,6 +7,7 @@
   fmt_ip6 compresses at best spot, not at first spot (Nikola Vladov)
   use inttypes.h to declare ints in uint*.h
   escape more in fmt_ldapescape
+  try to catch malicious input in textcode fmt_* functions
 
 0.25:
   array_allocate no longer truncates the array

textcode/fmt_base64.c

@@ -5,8 +5,8 @@
 size_t fmt_base64(char* dest,const char* src,size_t len) {
   register const unsigned char* s=(const unsigned char*) src;
   unsigned short bits=0,temp=0;
-  unsigned long written=0,i;
+  size_t written=0,i;
-  if (!dest) return ((len+2)/3)*4;
+  if (!dest) return (len>((size_t)-1)/2)?(size_t)-1:((len+2)/3)*4;
   for (i=0; i<len; ++i) {
     temp<<=8; temp+=s[i]; bits+=8;
     while (bits>6) {

textcode/fmt_cescape.c

@@ -41,6 +41,8 @@ size_t fmt_cescape2(char* dest,const char* src,size_t len,const char* escapeme)
 	}
 	break;
     }
+    /* in case someone gives us malicious input */
+    if (written>((size_t)-1)/2) return (size_t)-1;
   }
   return written;
 }

textcode/fmt_hexdump.c

@@ -6,6 +6,7 @@
 size_t fmt_hexdump(char* dest,const char* src,size_t len) {
   register const unsigned char* s=(const unsigned char*) src;
   size_t written=0,i;
+  if (!dest) return (len>((size_t)-1)/2)?(size_t)-1:len*2;
   for (i=0; i<len; ++i) {
     dest[written]=fmt_tohex(s[i]>>4);
     dest[written+1]=fmt_tohex(s[i]&15);

textcode/fmt_html.c

@@ -19,6 +19,8 @@ size_t fmt_html(char* dest,const char* src,size_t len) {
 	break;
     default: if (dest) dest[written]=s[i]; ++written; break;
     }
+    /* in case someone gives us malicious input */
+    if (written>((size_t)-1)/2) return (size_t)-1;
   }
   return written;
 }

textcode/fmt_ldapescape.c

@@ -18,6 +18,8 @@ size_t fmt_ldapescape(char* dest,const char* src,size_t len) {
     } else {
       if (dest) dest[written]=s[i]; ++written;
     }
+    /* in case someone gives us malicious input */
+    if (written>((size_t)-1)/2) return (size_t)-1;
   }
   return written;
 }

textcode/fmt_quotedprintable.c

@@ -17,6 +17,8 @@ size_t fmt_quotedprintable2(char* dest,const char* src,size_t len,const char* es
     } else {
       if (dest) dest[written]=s[i]; ++written;
     }
+    /* in case someone gives us malicious input */
+    if (written>((size_t)-1)/2) return (size_t)-1;
   }
   return written;
 }

textcode/fmt_to_array.c

@@ -4,7 +4,8 @@
 void fmt_to_array(size_t (*func)(char*,const char*,size_t),
 		  array* a,const char* src,size_t len) {
   size_t needed=func(0,src,len);
-  if (array_allocate(a,1,array_bytes(a)+needed-1)) {
+  if (array_bytes(a)+needed>needed &&
+      array_allocate(a,1,array_bytes(a)+needed-1)) {
     char* x=((char*)array_start(a))+array_bytes(a)-needed;
     func(x,src,len);
   } else

textcode/fmt_tofrom_array.c

@@ -7,7 +7,8 @@ void fmt_tofrom_array(size_t (*func)(char*,const char*,size_t),
   char* x;
   if (array_failed(dest) || array_failed(src)) { array_fail(dest); return; }
   needed=func(0,array_start(src),array_bytes(src));
-  if (array_allocate(dest,1,array_bytes(dest)+needed-1)) {
+  if (array_bytes(dest)+needed>needed &&
+      array_allocate(dest,1,array_bytes(dest)+needed-1)) {
     x=((char*)array_start(dest))+array_bytes(dest)-needed;
     func(x,array_start(src),array_bytes(src));
   } else

textcode/fmt_urlencoded.c

@@ -25,6 +25,8 @@ size_t fmt_urlencoded2(char* dest,const char* src,size_t len,const char* escapem
     } else {
       if (dest) dest[written]=s[i]; ++written;
     }
+    /* in case someone gives us malicious input */
+    if (written>((size_t)-1)/2) return (size_t)-1;
   }
   return written;
 }

textcode/fmt_uuencoded.c

@@ -11,6 +11,7 @@ size_t fmt_uuencoded(char* dest,const char* src,size_t len) {
   register const unsigned char* s=(const unsigned char*) src;
   const char* orig=dest;
   size_t tmp;
+  if (!dest) return len>((size_t)-1)/2?(size_t)-1:(len+2)/3*4;
   while (len) {
     {
       register unsigned int diff;

textcode/fmt_yenc.c

@@ -33,6 +33,8 @@ dontescape:
 	if (dest) dest[written]='\n'; ++written; linelen=0;
       }
     }
+    /* in case someone gives us malicious input */
+    if (written>((size_t)-1)/2) return (size_t)-1;
   }
   if (linelen) {
     if (dest) dest[written]='\n'; ++written; linelen=0;