1 files changed, 27 insertions, 0 deletions
diff --git a/app/validators/rsa_key_validator.rb b/app/validators/rsa_key_validator.rb
new file mode 100644
index 00000000000..64595454a8c
--- /dev/null
+++ b/app/validators/rsa_key_validator.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+# RsaKeyValidator
+#
+# Custom validator for RSA private keys.
+#
+#   class Project < ActiveRecord::Base
+#     validates :signing_key, rsa_key: true
+#   end
+#
+class RsaKeyValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    unless valid_rsa_key?(value)
+      record.errors.add(attribute, "is not a valid RSA key")
+    end
+  end
+
+  private
+
+  def valid_rsa_key?(value)
+    return false unless value
+
+    OpenSSL::PKey::RSA.new(value)
+  rescue OpenSSL::PKey::RSAError
+    false
+  end
+end