[Question] How to open and decode a string line by line when it was before encrypted

[Piioo]

Environment

Provide at least:

• ruby 2.7.6p219
• symmetric-encryption (4.5.0)
• Rails 6

Expected Behavior

When I encrypt a string with SymmetricEncryption.encrypt then it should be decrypted by SymmetricEncryption::Reader.open line by line too.
https://encryption.rocketjob.io/ -> Large File Encryption

Actual Behavior

This code is not working, when I only pass the encrypted string into the open method

foo = SymmetricEncryption.encrypt('foo', random_iv: false, compress: false, type: :string)
foo = StringIO.new(foo)
SymmetricEncryption::Reader.open(foo) do |file|
  file.each_line do |line|
     puts '###############'
     puts line
  end
end

# OpenSSL::Cipher::CipherError: bad decrypt

But it works when I Base64.decode64 the string before. But does the line by line have any sense in large files, when we have first to decode64 it?

foo = SymmetricEncryption.encrypt('foo', random_iv: false, compress: false, type: :string)
foo = StringIO.new(Base64.decode64(foo))
SymmetricEncryption::Reader.open(foo) do |file|
  file.each_line do |line|
     puts '###############'
     puts line
  end
end

# ###############
# foo