Support PBKDF2 using SHA512

[jefftrudeau]

No description provided.

[dblessing]

@carlosantoniodasilva Is this something you're open to accepting? Happy to help move it forward if it's agreeable.

[dblessing]

I tested these changes in our own project and provided feedback on what we experienced. Thanks for your contribution @jefftrudeau. I hope the maintainers will accept this.

[dblessing]

Suggested change

	hash = OpenSSL::Digest::SHA512.new
	hash = OpenSSL::Digest.new('SHA512').new

[dblessing]

If comparing unmatching values of differing length, this fails with mismatch length error. This should use Devise.secure_compare instead, which should also do a fixed length comparison, but also does an initial byte size/length check.

Suggested change

	ActiveSupport::SecurityUtils.fixed_length_secure_compare(encrypted_password, value_to_test)
	Devise.secure_compare(encrypted_password, value_to_test)

[dblessing]

Suggested change

	).unpack('H*')[0]
	).unpack1('H*')

[dblessing]

If a password is entirely numeric this function will fail trying due to implicit conversion of integer to string.

Suggested change

	password,
	password.to_s,

[jefftrudeau]

@dblessing @carlosantoniodasilva I rebased our branch against main and created a new PR: #25