Add basic implementation of ImportAsymmetricKey

app/interactors/import_asymmetric_key.rb

@@ -6,5 +6,93 @@ class ImportAsymmetricKey
   RSA_BITS_RE = /^RSA Public-Key: \((\d+) bit\)$/.freeze
   ECURVE_CURVE_RE = /^ASN1 OID: ((-|\w)+)$/.freeze
 
-  def call; end
+  before :unset_asymmetric_key
+  before :sanitize_public_key_der
+  before :sanitize_public_key_pem
+  before :set_public_key_openssl_pkey
+  before :validate_public_key_der
+  before :validate_public_key_pem
+
+  def call
+    if context.public_key_openssl_pkey.private?
+      context.fail!
+    end
+
+    find_asymmetric_key
+
+    return unless context.asymmetric_key.nil?
+
+    case context.public_key_openssl_pkey
+    when OpenSSL::PKey::RSA then create_rsa_key
+    when OpenSSL::PKey::EC  then create_ecurve_key
+    else context.fail!
+    end
+  end
+
+  def find_asymmetric_key
+    context.asymmetric_key = AsymmetricKey.find_by(
+      public_key_der: context.public_key_openssl_pkey.to_der,
+    )
+  end
+
+  def create_rsa_key
+    context.asymmetric_key = RSAKey.create!(
+      public_key_pem: context.public_key_openssl_pkey.to_pem,
+      public_key_der: context.public_key_openssl_pkey.to_der,
+      sha1: Digest::SHA1.hexdigest(context.public_key_openssl_pkey.to_der),
+      sha256: Digest::SHA256.hexdigest(context.public_key_openssl_pkey.to_der),
+      bits: context.public_key_openssl_pkey.to_text.lines
+                   .grep(RSA_BITS_RE).first.match(RSA_BITS_RE)[1].to_i,
+    )
+  end
+
+  def create_ecurve_key
+    context.asymmetric_key = EcurveKey.create!(
+      public_key_pem: context.public_key_openssl_pkey.to_pem,
+      public_key_der: context.public_key_openssl_pkey.to_der,
+      sha1: Digest::SHA1.hexdigest(context.public_key_openssl_pkey.to_der),
+      sha256: Digest::SHA256.hexdigest(context.public_key_openssl_pkey.to_der),
+      curve: context.public_key_openssl_pkey.to_text.lines
+                    .grep(ECURVE_CURVE_RE).first.match(ECURVE_CURVE_RE)[1],
+    )
+  end
+
+private
+
+  def unset_asymmetric_key
+    context.asymmetric_key = nil
+  end
+
+  def sanitize_public_key_der
+    context.public_key_der = String(context.public_key_der).presence&.dup.freeze
+  end
+
+  def sanitize_public_key_pem
+    context.public_key_pem = String(context.public_key_pem).lines.map do |line|
+      "#{line.strip}\n"
+    end.join.presence.freeze
+  end
+
+  def set_public_key_openssl_pkey
+    context.public_key_openssl_pkey ||= OpenSSL::PKey.read(
+      context.public_key_der || context.public_key_pem || '',
+      '',
+    )
+  rescue OpenSSL::PKey::PKeyError
+    context.fail!
+  end
+
+  def validate_public_key_der
+    return if context.public_key_der.blank?
+    return if context.public_key_der == context.public_key_openssl_pkey.to_der
+
+    raise 'Invalid DER'
+  end
+
+  def validate_public_key_pem
+    return if context.public_key_pem.blank?
+    return if context.public_key_pem == context.public_key_openssl_pkey.to_pem
+
+    raise 'Invalid PEM'
+  end
 end