ocaml http/1, http/2 and websocket client and server library
gdiazlo.tngl.sh
1let initialized = ref false
2
3let ensure_initialized () =
4 if not !initialized then begin
5 Mirage_crypto_rng_unix.use_default ();
6 initialized := true
7 end
8
9let generate n =
10 ensure_initialized ();
11 Mirage_crypto_rng.generate n
12
13let generate_bytes n = Bytes.of_string (Mirage_crypto_rng.generate n)
14
15let int bound =
16 if bound <= 0 then invalid_arg "Secure_random.int: bound must be positive";
17 let rec sample () =
18 let s = Mirage_crypto_rng.generate 8 in
19 let v =
20 (Char.code s.[0] lsl 56)
21 lor (Char.code s.[1] lsl 48)
22 lor (Char.code s.[2] lsl 40)
23 lor (Char.code s.[3] lsl 32)
24 lor (Char.code s.[4] lsl 24)
25 lor (Char.code s.[5] lsl 16)
26 lor (Char.code s.[6] lsl 8)
27 lor Char.code s.[7]
28 in
29 let v = v land max_int in
30 let limit = max_int - (max_int mod bound) in
31 if v < limit then v mod bound else sample ()
32 in
33 sample ()
34
35let token ?(bytes = 32) () =
36 let raw = generate bytes in
37 Base64.encode_string ~pad:false ~alphabet:Base64.uri_safe_alphabet raw
38
39let uuid () =
40 let bytes = generate_bytes 16 in
41 Bytes.set bytes 6
42 (Char.chr (Char.code (Bytes.get bytes 6) land 0x0f lor 0x40));
43 Bytes.set bytes 8
44 (Char.chr (Char.code (Bytes.get bytes 8) land 0x3f lor 0x80));
45 let hex = Bytes.create 36 in
46 let hex_chars = "0123456789abcdef" in
47 let pos = ref 0 in
48 for i = 0 to 15 do
49 if i = 4 || i = 6 || i = 8 || i = 10 then begin
50 Bytes.set hex !pos '-';
51 incr pos
52 end;
53 let b = Char.code (Bytes.get bytes i) in
54 Bytes.set hex !pos hex_chars.[b lsr 4];
55 incr pos;
56 Bytes.set hex !pos hex_chars.[b land 0x0f];
57 incr pos
58 done;
59 Bytes.to_string hex