AWS KMS サービスを利用して、秘密にしたいデータをコードの中で扱えるようにする

aws_kms_client.rb

require 'aws-sdk'

# Please set your own key id
# Ref: https://console.aws.amazon.com/iam/home?region=ap-northeast-1#/encryptionKeys/ap-northeast-1
key_id = 'arn:aws:kms:ap-northeast-1:000000000000:key/00000000-0000-0000-0000-000000000000' # note: keep secret key_id, export to environment variable

kms = Aws::KMS::Client.new(
  region: 'ap-northeast-1'
)

response = kms.encrypt(
  key_id: key_id,
  plaintext: 'my_sensitive_text_data'
)

p ciphertext_blob = response.dig(:ciphertext_blob).to_s
# => "\x01\x01\x02\x00xS\xBB\xBE\xC5\x03G\xE9>fz{\xBEyW\x8E&\x01I\xFB\xBF\xBD\xB0Vfk(snip)...

response2 = kms.decrypt(
  ciphertext_blob: ciphertext_blob
)

p response2.dig(:plaintext)
# => 'my_sensitive_text_data'