use cryptokit by default

add API: string_to_hexstring

Author: sangkilc

myocamlbuild.ml

@@ -76,6 +76,7 @@ let _ = dispatch begin function
          "pkg_batteries";
          "pkg_bitstring";
          "pkg_bitstring.syntax";
+         "pkg_cryptokit";
         ];
 
       tag_file "src/ocamlExploit.ml" ["syntax_camlp4o";

src/ocamlExploit.ml

@@ -111,50 +111,51 @@ let explode s =
   in
   exp (String.length s - 1) []
 
-let printhex little str =
-  let print_chunk chunk =
-    Printf.printf "%08lx" chunk
+let string_to_hexstring little str =
+  let accumulate acc chunk =
+    Printf.sprintf "%s%08lx" acc chunk
   in
-  let rec print_little_loop bs =
+  let rec little_loop acc bs =
     bitmatch bs with
       | {chunk : 32 : littleendian; rest  : -1 : bitstring }
-        when bitstring_length rest = 0 -> print_chunk chunk
+        when bitstring_length rest = 0 -> accumulate acc chunk
       | {chunk : 32 : littleendian;
          chunk2 : 24 : littleendian; rest : -1 : bitstring }
         when bitstring_length rest = 0 ->
-          (print_chunk chunk; Printf.printf "%06x\n" chunk2)
+          let acc = accumulate acc chunk in
+          Printf.sprintf "%s%06x\n" acc chunk2
       | {chunk : 32 : littleendian; rest  : -1 : bitstring } ->
-          (print_chunk chunk; print_little_loop rest)
+          let acc = accumulate acc chunk in
+          little_loop acc rest
       | {chunk : 8 : littleendian; rest : -1 : bitstring }
         when bitstring_length rest = 0 ->
-          Printf.printf "%02x\n" chunk
+          Printf.sprintf "%s%02x\n" acc chunk
       | {chunk : 16 : littleendian; rest : -1 : bitstring }
         when bitstring_length rest = 0 ->
-          Printf.printf "%04x\n" chunk
+          Printf.sprintf "%s%04x\n" acc chunk
   in
-  let rec print_big_loop bs =
+  let rec big_loop acc bs =
     bitmatch bs with
       | {chunk : 32 : bigendian; rest : -1 : bitstring }
-        when bitstring_length rest = 0 -> print_chunk chunk
+        when bitstring_length rest = 0 -> accumulate acc chunk
       | {chunk : 32 : bigendian;
          chunk2 : 24 : bigendian; rest : -1 : bitstring }
         when bitstring_length rest = 0 ->
-          (print_chunk chunk; Printf.printf "%06x\n" chunk2)
+          let acc = accumulate acc chunk in
+          Printf.sprintf "%s%06x\n" acc chunk2
       | {chunk : 32 : bigendian; rest : -1 : bitstring } ->
-          (print_chunk chunk; print_big_loop rest)
+          let acc = accumulate acc chunk in
+          big_loop acc rest
       | {chunk : 8 : bigendian; rest : -1 : bitstring }
         when bitstring_length rest = 0 ->
-          Printf.printf "%02x\n" chunk
+          Printf.sprintf "%s%02x\n" acc chunk
       | {chunk : 16 : bigendian; rest : -1 : bitstring }
         when bitstring_length rest = 0 ->
-          Printf.printf "%04x\n" chunk
+          Printf.sprintf "%s%04x\n" acc chunk
   in
   let bs = bitstring_of_string str in
-  begin
-    if little then print_little_loop bs
-    else print_big_loop bs
-  end;
-  flush stdout
+  if little then little_loop "" bs
+  else big_loop "" bs
 
 let hexdump str =
   bitstring_of_string str |> hexdump_bitstring stdout

src/ocamlExploit.mli

@@ -45,13 +45,13 @@ val int32_to_hexstring : int32 -> string
 (** get a string from a hexstring *)
 val hexstring_to_string : string -> string
 
+(** get a hexstring from the given string
+    little specifies whether the string is little endian or not *)
+val string_to_hexstring : bool -> string -> string
+
 (** simple print, but always flush *)
 val print : string -> unit
 
-(** print the given string in hexstring,
-    little specifies whether the string is little endian or not *)
-val printhex : bool -> string -> unit
-
 (** print the given string in a format similar to hexdump *)
 val hexdump : string -> unit