android-ecc.rb

#!/usr/bin/env ruby

require 'openssl'
require 'tempfile'

OpenSSL::PKey::EC.send :alias_method, :private?, :private_key?

key = OpenSSL::PKey::EC.new('secp256k1')
key.generate_key

File.write 'mykey.pem', key.to_pem

cert = OpenSSL::X509::Certificate.new
cert.version = 0x2
cert.issuer = OpenSSL::X509::Name.new([["commonName", "Satoshi Nakamoto"]])
cert.not_before = Time.new(2015, 11, 25, 12, 0, 0, "-07:00")
cert.not_after = Time.new(2033, 10, 22, 0, 0, 0, "-07:00")
cert.subject = cert.issuer
cert.public_key = key
cert.add_extension OpenSSL::X509::ExtensionFactory.new(cert, cert).create_ext("subjectKeyIdentifier", "hash")

cert.sign(key, OpenSSL::Digest::SHA256.new)

IO.popen("openssl pkcs12 -export -inkey 'mykey.pem' -out 'mykey.p12' -name 'mykey' -password 'pass:changeit'", 'w').write(cert.to_pem)

exec "keytool -srcstoretype 'PKCS12' -importkeystore -srckeystore 'mykey.p12' -destkeystore 'keystore.jks' -srcstorepass 'changeit' -deststorepass 'changeit'"

Nevermind :( https://code.google.com/p/android/issues/detail?id=189170