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Crystal

Digest

abstract class `Digest`
inherits `Reference` ¶

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 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

Crystal::Digest::MD5 OpenSSL::Digest

Methods¶

`#<<(data) : self` ¶

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

abstract `#digest_size : Int32` ¶

Returns the digest output size in bytes.

`#file(file_name : Path | String) : self` ¶

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

`#final(dst : Bytes) : Bytes` ¶

`#final : Bytes` ¶

Returns the final digest output.

This method can only be called once and raises FinalizedError on subsequent calls.

Note

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

abstract `#final_impl(dst : Bytes) : Nil` ¶

Stores the output digest of #digest_size bytes in dst.

`#reset : self` ¶

abstract `#reset_impl : Nil` ¶

Resets the object to it's initial state.

`#update(data : Bytes) : self` ¶

`#update(io : IO) : self` ¶

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

`#update(data) : self` ¶

abstract `#update_impl(data : Bytes) : Nil` ¶

Hashes data incrementally.