abstract class Digest

Overview

Digest is the base type of hashing algorithms like Digest::MD5, Digest::SHA1, Digest::SHA256, or Digest::SHA512.

A Digest instance holds the state of an ongoing hash calculation. It can receive new data to include in the hash via #update, #<<, or #file. Once all data is included, use #final or #hexfinal to get the hash. This will mark the ongoing calculation as finished. A finished calculation can't receive new data.

A digest.dup.final call may be used to get an intermediate hash value.

Use #reset to reuse the Digest instance for a new calculation.

Direct Known Subclasses

Defined in:

digest/digest.cr

Instance Method Summary

Instance methods inherited from class Reference

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, initialize initialize, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil) same?, to_s(io : IO) : Nil to_s

Constructor methods inherited from class Reference

new new

Instance methods inherited from class Object

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, inspect(io : IO) : Nil
inspect : String inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil!(message)
not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Class methods inherited from class Object

from_json(string_or_io, root : String)
from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml

Instance Method Detail

def <<(data) : self #

Reads the io's data and updates the digest with it.


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abstract def digest_size : Int32 #

Returns the digest output size in bytes.


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def file(file_name : Path | String) : self #

Reads the file's content and updates the digest with it.


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def final(dst : Bytes) : Bytes #

Puts the final digest output into dst.

Faster than the Bytes allocating version. Use when hashing in loops.

#final or #hexfinal can only be called once and raises FinalizedError on subsequent calls.

NOTE .dup.final(dst) call may be used to get an intermediate hash value.


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def final : Bytes #

Returns the final digest output.

#final or #hexfinal can only be called once and raises FinalizedError on subsequent calls.

NOTE .dup.final call may be used to get an intermediate hash value.


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abstract def final_impl(dst : Bytes) : Nil #

Stores the output digest of #digest_size bytes in dst.


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def hexfinal(dst : Bytes) : Nil #

Writes a hexadecimal-encoded digest to dst.

Faster than the String allocating version. Use when hashing in loops.

#final or #hexfinal can only be called once and raises FinalizedError on subsequent calls.

NOTE .dup.final call may be used to get an intermediate hash value.


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def hexfinal(io : IO) : Nil #

Writes a hexadecimal-encoded digest to IO.

Faster than the String allocating version.

#final or #hexfinal can only be called once and raises FinalizedError on subsequent calls.

NOTE .dup.final call may be used to get an intermediate hash value.

This method is restricted to a maximum digest size of 64 bits. Implementations that allow a larger digest size should override this method to use a larger buffer.


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def hexfinal : String #

Returns a hexadecimal-encoded digest in a new String.

#final or #hexfinal can only be called once and raises FinalizedError on subsequent calls.

NOTE .dup.hexfinal call may be used to get an intermediate hash value.


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def reset : self #

Resets the state of this object. Use to get another hash value without creating a new object.


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abstract def reset_impl : Nil #

Resets the object to it's initial state.


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def update(data : Bytes) : self #

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def update(io : IO) : self #

Reads the io's data and updates the digest with it.


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def update(data) : self #

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abstract def update_impl(data : Bytes) : Nil #

Hashes data incrementally.


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