diff options
Diffstat (limited to 'activesupport/lib/active_support/key_generator.rb')
| -rw-r--r-- | activesupport/lib/active_support/key_generator.rb | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/key_generator.rb b/activesupport/lib/active_support/key_generator.rb new file mode 100644 index 0000000000..04d170f801 --- /dev/null +++ b/activesupport/lib/active_support/key_generator.rb @@ -0,0 +1,23 @@ +require 'openssl' + +module ActiveSupport + # KeyGenerator is a simple wrapper around OpenSSL's implementation of PBKDF2 + # It can be used to derive a number of keys for various purposes from a given secret. + # This lets rails applications have a single secure secret, but avoid reusing that + # key in multiple incompatible contexts. + class KeyGenerator + def initialize(secret, options = {}) + @secret = secret + # The default iterations are higher than required for our key derivation uses + # on the off chance someone uses this for password storage + @iterations = options[:iterations] || 2**16 + end + + # Returns a derived key suitable for use. The default key_size is chosen + # to be compatible with the default settings of ActiveSupport::MessageVerifier. + # i.e. OpenSSL::Digest::SHA1#block_length + def generate_key(salt, key_size=64) + OpenSSL::PKCS5.pbkdf2_hmac_sha1(@secret, salt, @iterations, key_size) + end + end +end |