Module Core_kernel.Md5

This module implements the MD5 message-digest algorithm as described IETF RFC 1321. t is the result type and val digest_string : string -> t is the implementation of the algorithm itself.

This is currently a thin wrapper over the Digest module in INRIA's standard library.

module Stable : sig ... end
module As_binary_string : sig ... end

Both bin_io and sexp serializations produce a binary 16-character string.

type t = Stable.V1.t

Intended to represent a 16-byte string that is the output of MD5 algorithm.

Note that any 16-byte string can be converted to this type, so a value of type t is not an evidence of someone having found an input corresponding to this output.

include sig ... end
val bin_read_t : t Bin_prot.Read.reader
val __bin_read_t__ : (int ‑> t) Bin_prot.Read.reader
val bin_reader_t : t Bin_prot.Type_class.reader
val bin_size_t : t Bin_prot.Size.sizer
val bin_write_t : t Bin_prot.Write.writer
val bin_writer_t : t Bin_prot.Type_class.writer
val bin_shape_t : Bin_prot.Shape.t
val t_of_sexp : Base.Sexp.t ‑> t
val sexp_of_t : t ‑> Base.Sexp.t
val hash_fold_t : Base.Hash.state ‑> t ‑> Base.Hash.state
val hash : t ‑> Base.Hash.hash_value
include Interfaces.Comparable with type t := t
include Core_kernel__.Comparable_intf.S_common
include Base.Comparable.S
include Base__.Comparable_intf.Polymorphic_compare
include Base.Comparisons.Infix
type t
val (>=) : t ‑> t ‑> bool
val (<=) : t ‑> t ‑> bool
val (=) : t ‑> t ‑> bool
val (>) : t ‑> t ‑> bool
val (<) : t ‑> t ‑> bool
val (<>) : t ‑> t ‑> bool
val equal : t ‑> t ‑> bool
val compare : t ‑> t ‑> int

compare t1 t2 returns 0 if t1 is equal to t2, a negative integer if t1 is less than t2, and a positive integer if t1 is greater than t2.

val min : t ‑> t ‑> t
val max : t ‑> t ‑> t
val ascending : t ‑> t ‑> int

ascending is identical to compare. descending x y = ascending y x. These are intended to be mnemonic when used like List.sort ~compare:ascending and List.sort ~cmp:descending, since they cause the list to be sorted in ascending or descending order, respectively.

val descending : t ‑> t ‑> int
val between : t ‑> low:t ‑> high:t ‑> bool

between t ~low ~high means low <= t <= high

val clamp_exn : t ‑> min:t ‑> max:t ‑> t

clamp_exn t ~min ~max returns t', the closest value to t such that between t' ~low:min ~high:max is true.

Raises if not (min <= max).

val clamp : t ‑> min:t ‑> max:t ‑> t Base.Or_error.t
include Base.Comparator.S with type t := t
type t
type comparator_witness
include Base__.Comparable_intf.Validate with type t := t
type t
val validate_lbound : min:t Base.Maybe_bound.t ‑> t Base.Validate.check
val validate_ubound : max:t Base.Maybe_bound.t ‑> t Base.Validate.check
val validate_bound : min:t Base.Maybe_bound.t ‑> max:t Base.Maybe_bound.t ‑> t Base.Validate.check
module Map : Map.S with type Key.t = t with type Key.comparator_witness = comparator_witness
module Set : Set.S with type Elt.t = t with type Elt.comparator_witness = comparator_witness
include Interfaces.Binable with type t := t
type t
include Core_kernel__.Binable0.S_only_functions with type t := t
type t
val bin_size_t : t Bin_prot.Size.sizer
val bin_write_t : t Bin_prot.Write.writer
val bin_read_t : t Bin_prot.Read.reader
val __bin_read_t__ : (int ‑> t) Bin_prot.Read.reader

This function only needs implementation if t exposed to be a polymorphic variant. Despite what the type reads, this does *not* produce a function after reading; instead it takes the constructor tag (int) before reading and reads the rest of the variant t afterwards.

val bin_shape_t : Bin_prot.Shape.t
val bin_writer_t : t Bin_prot.Type_class.writer
val bin_reader_t : t Bin_prot.Type_class.reader
include Interfaces.Hashable with type t := t
include Hashable.Common
type t
include sig ... end
val compare : t ‑> t ‑> Core_kernel__.Import.int
val hash_fold_t : Base.Hash.state ‑> t ‑> Base.Hash.state
val hash : t ‑> Base.Hash.hash_value
val hashable : t Hashtbl.Hashable.t
module Table : Hashtbl.S with type key = t
module Hash_set : Hash_set.S with type elt = t
module Hash_queue : Hash_queue.S with type Key.t = t
val digest_num_bytes : int

digest_num_bytes = 16 is the size of the digest in bytes.

val to_binary : t ‑> string

Binary representations are 16 bytes long, and not human readable.

val of_binary_exn : string ‑> t
val to_hex : t ‑> string

to_hex prints each byte of t as a big-endian sequence of 2 hex digits (e.g. byte 31 is written as "1f") and then concatenates them. For example, 

      Md5.to_hex (Md5.digest_string "a") =
      Md5.to_hex (
        Md5.of_binary_exn
          "\x0c\xc1\x75\xb9\xc0\xf1\xb6\xa8\x31\xc3\x99\xe2\x69\x77\x26\x61") =
      "0cc175b9c0f1b6a831c399e269772661"
val of_hex_exn : string ‑> t

The inverse of to_hex. This function ignores case. It will raise an exception if the string is not a 32-byte-long string of hex digits.

val digest_string : string ‑> t
val digest_bytes : bytes ‑> t
val digest_subbytes : bytes ‑> pos:int ‑> len:int ‑> t

digest_subbytes m ~pos ~len computes Md5 digest of the substring of m of length len starting at pos.

val digest_file_blocking_without_releasing_runtime_lock : string ‑> t

digest_file_blocking_without_releasing_runtime_lock filename reads the contents of file filename and computes its digest.

WARNING: This function does digest computation with OCaml global lock held, so it can be slow and make the other threads starve. Use Core.Md5.digest_file_blocking instead.

val digest_channel_blocking_without_releasing_runtime_lock : Pervasives.in_channel ‑> len:int ‑> t

Reads len bytes from the given channel and computes md5 digest of that.

WARNING: This function does digest computation with OCaml global lock held, so it can be slow and make the other threads starve. Use Core.Md5.digest_fd_blocking instead.

val input_blocking : Pervasives.in_channel ‑> t

Reads an Md5 digest from the given channel (in a format written by output_blocking)

val output_blocking : t ‑> Pervasives.out_channel ‑> unit

Writes the Md5 digest to the given channel.

val string : string ‑> t
val bytes : bytes ‑> t
val subbytes : bytes ‑> int ‑> int ‑> t
val from_hex : string ‑> t
val file : string ‑> t
val channel : Pervasives.in_channel ‑> int ‑> t
val output : Pervasives.out_channel ‑> t ‑> unit
val input : Pervasives.in_channel ‑> t
val digest_bin_prot : 'a Bin_prot.Type_class.writer ‑> 'a ‑> t

digest_bin_prot w x digests the serialization of x by w. It is a cheap way (in dev time) to compute the digest of an ocaml value, for a fixed and deterministic serialization function. It is currently implemented inefficiently and allocates large strings.