NAME¶

Digest - MD5 message digest.

Module¶

Module Digest

Documentation¶

Module Digest
: sig end

MD5 message digest.

This module provides functions to compute 128-bit 'digests' of arbitrary-length strings or files. The algorithm used is MD5.

The MD5 hash function is not cryptographically secure. Hence, this module should not be used for security-sensitive applications. More recent, stronger cryptographic primitives should be used instead.

type t = string

The type of digests: 16-character strings.

val compare : t -> t -> int

The comparison function for 16-character digest, with the same specification as compare and the implementation shared with String.compare . Along with the type t , this function compare allows the module Digest to be passed as argument to the functors Set.Make and Map.Make .

Since 4.00.0

val equal : t -> t -> bool

The equal function for 16-character digest.

Since 4.03.0

val string : string -> t

Return the digest of the given string.

val bytes : bytes -> t

Return the digest of the given byte sequence.

Since 4.02.0

val substring : string -> int -> int -> t

Digest.substring s ofs len returns the digest of the substring of s starting at index ofs and containing len characters.

val subbytes : bytes -> int -> int -> t

Digest.subbytes s ofs len returns the digest of the subsequence of s starting at index ofs and containing len bytes.

Since 4.02.0

val channel : in_channel -> int -> t

If len is nonnegative, Digest.channel ic len reads len characters from channel ic and returns their digest, or raises End_of_file if end-of-file is reached before len characters are read. If len is negative, Digest.channel ic len reads all characters from ic until end-of-file is reached and return their digest.

val file : string -> t

Return the digest of the file whose name is given.

val output : out_channel -> t -> unit

Write a digest on the given output channel.

val input : in_channel -> t

Read a digest from the given input channel.

val to_hex : t -> string

Return the printable hexadecimal representation of the given digest.

Raises Invalid_argument if the argument is not exactly 16 bytes.

val from_hex : string -> t

Convert a hexadecimal representation back into the corresponding digest.

Since 4.00.0

Raises Invalid_argument if the argument is not exactly 32 hexadecimal characters.