Serve public keys through webapp

Add a utility script which uses the public key served over HTTP
to encrypt the secret.

Change-Id: If0e4e4f8509518c8440814e8088a343489b5c553
diff --git a/tests/fixtures/public.pem b/tests/fixtures/public.pem
new file mode 100644
index 0000000..33a78c4
--- /dev/null
+++ b/tests/fixtures/public.pem
@@ -0,0 +1,14 @@
+-----BEGIN PUBLIC KEY-----
+MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAsGqZLUUwV/EZJKddMS20
+6mH7qYmqYhWLo/TUlpDt2JuEaBqCYV8mF9LsjpoqM/Pp0U/r5aQLDUXbRLDn+K+N
+qbvTJajYxHJicP1CAWg1eKUNZjUaya5HP4Ow1hS7AeiF4TSRdiwtHT/gJO2NSsav
+yc30/meKt0WBgbYlrBB81HEQjYWnajf/4so5E8DdrC9tAqmmzde1qcTz7ULouIz5
+3hjp/U3yVMFbpawv194jzHvddmAX3aEUByx2t6lP7dhOAEIEmzmh15hRbacxQI5a
+YWv+ZR0z9PqdwwD+DBbb1AwiX5MJjtIoVCmkEZvcUFiDicyteNMCa5ulpj2SF0oH
+4MlialOP6MiJnmxklDYO07AM/qomcU55pCD8ctu1yD/UydecLk0Uj/9XxqmPQJFE
+cstdXJZQfr5ZNnChOEg6oQ9UImWjav8HQsA6mFW1oAKbDMrgEewooWriqGW5pYtR
+7JBfph6Mt5HGaeH4uqYpb1fveHG1ODa7HBnlNo3qMendBb2wzHGCgtUgWnGfp24T
+sUOUlndCXYhsYbOZbCTW5GwElK0Gri06KPpybY43AIaxcxqilVh5Eapmq7axBm4Z
+zbTOfv15L0FIemEGgpnklevQbZNLIrcE0cS/13qJUvFaYX4yjrtEnzZ3ntjXrpFd
+gLPBKn7Aqf6lWz6BPi07axECAwEAAQ==
+-----END PUBLIC KEY-----