The type of digests: 16-byte strings.

The comparison function for 16-byte digests, with the same specification as Stdlib.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

The equal function for 16-byte digests.

• since 4.03

Return the digest of the given string.

Return the digest of the given byte sequence.

• since 4.02

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

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

• since 4.02

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.

Return the digest of the file whose name is given.

Write a digest on the given output channel.

Read a digest from the given input channel.

Return the printable hexadecimal representation of the given digest.

• raises Invalid_argument

  if the argument is not exactly 16 bytes.

Convert a hexadecimal representation back into the corresponding digest.

• raises Invalid_argument

  if the argument is not exactly 32 hexadecimal characters.

• since 5.2

Same function as Digest.of_hex.

• since 4.00

The signature for a hash function that produces digests of length hash_length from character strings, byte arrays, and files.

BLAKE128 is the BLAKE2b hash function producing 128-bit (16-byte) digests. It is cryptographically secure. However, the small size of the digests enables brute-force attacks in 2{^64} attempts.

BLAKE256 is the BLAKE2b hash function producing 256-bit (32-byte) digests. It is cryptographically secure, and the digests are large enough to thwart brute-force attacks.

BLAKE512 is the BLAKE2b hash function producing 512-bit (64-byte) digests. It is cryptographically secure, and the digests are large enough to thwart brute-force attacks.

MD5 is the MD5 hash function. It produces 128-bit (16-byte) digests and is not cryptographically secure at all. It should be used only for compatibility with earlier designs that mandate the use of MD5.