diff options
Diffstat (limited to 'sid.ml')
| -rw-r--r-- | sid.ml | 55 |
1 files changed, 50 insertions, 5 deletions
@@ -7,9 +7,9 @@ type sid = } and sub_auths = U32.t array -let sub_auth_max = 15 - -let sizeof_sub_auth = 4 +let sizeof_ident_auth = 6 +let sizeof_sub_auth = 4 +let max_subauth_count = 15 let create_unsafe sa ia = { sid_ident_auth = ia @@ -71,7 +71,7 @@ module StringFmt = struct let read_decimal_u64 = read_decimal_string U64.of_string let read_decimal_u32 = read_decimal_string U32.of_string - + (* * The spec ([MS-DTYP]): * @@ -92,7 +92,7 @@ module StringFmt = struct let p = 4 in let p, ia = read_decimal_u64 s p in let sa = ref [] and p' = ref p in - while !p' < n && List.length !sa < sub_auth_max do + while !p' < n && List.length !sa < max_subauth_count do expect_char s '-' !p'; let np, d = read_decimal_u32 s (!p' + 1) in sa := d :: !sa; @@ -129,6 +129,8 @@ end (* [module StringFmt] *) module PacketRep = struct (* [MS-DTYP] 2.4.22 *) + (* XXX configurable endianness *) + let encode s = let nsa = Array.length s.sid_sub_auths in let l = 8 + nsa * sizeof_sub_auth in @@ -152,6 +154,49 @@ module PacketRep = struct (* [MS-DTYP] 2.4.22 *) s.sid_sub_auths; Bytes.unsafe_of_string (Buffer.contents b) + let wordlen = 4 (* sizeof int *) + let min_pktrep_len = 1 + 1 + sizeof_ident_auth + let max_pktrep_len = 1 + 1 + + sizeof_ident_auth + + max_subauth_count * sizeof_sub_auth + let pktrep_sa_off = min_pktrep_len + + let decode b = + let l = Bytes.length b in + if l < min_pktrep_len || max_pktrep_len < l then + Error (Printf.sprintf + "bad input size: expected %d–%d B, got %d B" + min_pktrep_len max_pktrep_len l) else + if l mod wordlen <> 0 then + Error (Printf.sprintf + "bad input size: not divisible by word length (%d)" + wordlen) else + let v = Bytes.get b 0 |> int_of_char in + if v <> 0x01 then + Error (Printf.sprintf + "input malformed: expected SID version=0x01, got 0x%0.2x" v) else + let nsa = Bytes.get b 1 |> int_of_char in + if max_subauth_count < nsa then + Error (Printf.sprintf + "input malformed: up to %d subAuthority elements permitted, \ + %d specified" + max_subauth_count nsa) else + let getbyte n ia = (* b[n] << (5 - (n - 2)) *) + U64.logor ia + (U64.shift_left (Bytes.get b n |> int_of_char |> U64.of_int) (5 - (n - 2))) + in + let ia = U64.zero + |> getbyte 2 |> getbyte 3 |> getbyte 4 + |> getbyte 5 |> getbyte 6 |> getbyte 7 in + let sas = Array.make nsa (U32.zero) in + for i = 0 to (nsa - 1) do + let off = pktrep_sa_off + i * sizeof_sub_auth in + sas.(i) <- U32.of_bytes_little_endian b off + done; + Ok { sid_ident_auth = ia + ; sid_sub_auths = sas + } + end (* [module PacketRep] *) module WellKnown = struct |