module SecurizeString::RSAMethods::InstanceMethods
Adds instance methods for OpenSSL::PKey::RSA support via inclusion of SecurizeString::RSAMethods
to a class.
Public Instance Methods
Interpret the contents of hte string asn a RSA private key, and extract the public key from it. If the contents are not a private key, then it will raise an exception.
# File lib/securize_string/rsa_methods.rb, line 112 def extract_public_key(format = :pem) pvt, pub = self.class.separate_keys(self, format) return pub end
Given an RSA private key, it decrypts the data string back into the original text.
# File lib/securize_string/rsa_methods.rb, line 64 def from_rsa(key) key = OpenSSL::PKey::RSA.new(key) plain_text = key.private? ? key.private_decrypt(self.to_s) : key.public_decrypt(self.to_s) return self.class.new(plain_text) end
Interpret the conents of the string as an RSA key, and determine if it is private.
# File lib/securize_string/rsa_methods.rb, line 104 def private_rsa_key? key = OpenSSL::PKey::RSA.new(self.to_s) return key.private? end
Interpret the conetents of the string as an RSA key, and determine if it is public.
Even though private keys contain all the information necessary to reconstitute a public key, this method returns false. This is in contrast to the behavior of OpenSSL::PKey::RSA, which return true for both public and private checks with a private key (since it reconstituted the public key and it is available for use).
# File lib/securize_string/rsa_methods.rb, line 98 def public_rsa_key? # There is an interesting bug I came across, where +public?+ can be true on a private key! return !private_rsa_key? end
Signs the given message using hte given private key.
By default, verifies using SHA256, but another digest method can be given using the list of DigestFinder
supported digests.
# File lib/securize_string/rsa_methods.rb, line 74 def sign(private_key, digest_method='SHA-256') digest_obj = DigestFinder.find(digest_method).new key = OpenSSL::PKey::RSA.new(private_key) return self.class.new( key.sign(digest_obj, self) ) end
Given an RSA public key, it RSA encrypts the data string.
Note that the key must be 11 bytes longer than the data string or it doesn’t work.
# File lib/securize_string/rsa_methods.rb, line 57 def to_rsa(key) key = OpenSSL::PKey::RSA.new(key) cipher_text = key.private? ? key.private_encrypt(self.to_s) : key.public_encrypt(self.to_s) return self.class.new(cipher_text) end
Verifies the given signature matches the messages digest, using the signer’s public key.
By default, verifies using SHA256, but another digest method can be given using the list of DigestFinder
supported digests.
# File lib/securize_string/rsa_methods.rb, line 85 def verify?(public_key, signature, digest_method='SHA-256') digest_obj = DigestFinder.find(digest_method).new key = OpenSSL::PKey::RSA.new(public_key) return key.verify(digest_obj, signature.to_s, self) end