1 files changed, 136 insertions, 0 deletions
diff --git a/lib/rubygems/security/signer.rb b/lib/rubygems/security/signer.rb
new file mode 100644
index 0000000000..29b03683b7
--- /dev/null
+++ b/lib/rubygems/security/signer.rb
@@ -0,0 +1,136 @@
+##
+# Basic OpenSSL-based package signing class.
+
+class Gem::Security::Signer
+
+  ##
+  # The chain of certificates for signing including the signing certificate
+
+  attr_accessor :cert_chain
+
+  ##
+  # The private key for the signing certificate
+
+  attr_accessor :key
+
+  ##
+  # The digest algorithm used to create the signature
+
+  attr_reader :digest_algorithm
+
+  ##
+  # The name of the digest algorithm, used to pull digests out of the hash by
+  # name.
+
+  attr_reader :digest_name # :nodoc:
+
+  ##
+  # Creates a new signer with an RSA +key+ or path to a key, and a certificate
+  # +chain+ containing X509 certificates, encoding certificates or paths to
+  # certificates.
+
+  def initialize key, cert_chain
+    @cert_chain = cert_chain
+    @key        = key
+
+    unless @key then
+      default_key  = File.join Gem.user_home, 'gem-private_key.pem'
+      @key = default_key if File.exist? default_key
+    end
+
+    unless @cert_chain then
+      default_cert = File.join Gem.user_home, 'gem-public_cert.pem'
+      @cert_chain = [default_cert] if File.exist? default_cert
+    end
+
+    @digest_algorithm = Gem::Security::DIGEST_ALGORITHM
+    @digest_name      = Gem::Security::DIGEST_NAME
+
+    @key = OpenSSL::PKey::RSA.new File.read @key if
+      @key and not OpenSSL::PKey::RSA === @key
+
+    if @cert_chain then
+      @cert_chain = @cert_chain.compact.map do |cert|
+        next cert if OpenSSL::X509::Certificate === cert
+
+        cert = File.read cert if File.exist? cert
+
+        OpenSSL::X509::Certificate.new cert
+      end
+
+      load_cert_chain
+    end
+  end
+
+  ##
+  # Loads any missing issuers in the cert chain from the trusted certificates.
+  #
+  # If the issuer does not exist it is ignored as it will be checked later.
+
+  def load_cert_chain # :nodoc:
+    return if @cert_chain.empty?
+
+    while @cert_chain.first.issuer.to_s != @cert_chain.first.subject.to_s do
+      issuer = Gem::Security.trust_dir.issuer_of @cert_chain.first
+
+      break unless issuer # cert chain is verified later
+
+      @cert_chain.unshift issuer
+    end
+  end
+
+  ##
+  # Sign data with given digest algorithm
+
+  def sign data
+    return unless @key
+
+    if @cert_chain.length == 1 and @cert_chain.last.not_after < Time.now then
+      re_sign_key
+    end
+
+    Gem::Security::SigningPolicy.verify @cert_chain, @key
+
+    @key.sign @digest_algorithm.new, data
+  end
+
+  ##
+  # Attempts to re-sign the private key if the signing certificate is expired.
+  #
+  # The key will be re-signed if:
+  # * The expired certificate is self-signed
+  # * The expired certificate is saved at ~/.gem/gem-public_cert.pem
+  # * There is no file matching the expiry date at
+  #   ~/.gem/gem-public_cert.pem.expired.%Y%m%d%H%M%S
+  #
+  # If the signing certificate can be re-signed the expired certificate will
+  # be saved as ~/.gem/gem-pubilc_cert.pem.expired.%Y%m%d%H%M%S where the
+  # expiry time (not after) is used for the timestamp.
+
+  def re_sign_key # :nodoc:
+    old_cert = @cert_chain.last
+
+    disk_cert_path = File.join Gem.user_home, 'gem-public_cert.pem'
+    disk_cert = File.read disk_cert_path rescue nil
+    disk_key  =
+      File.read File.join(Gem.user_home, 'gem-private_key.pem') rescue nil
+
+    if disk_key == @key.to_pem and disk_cert == old_cert.to_pem then
+      expiry = old_cert.not_after.strftime '%Y%m%d%H%M%S'
+      old_cert_file = "gem-public_cert.pem.expired.#{expiry}"
+      old_cert_path = File.join Gem.user_home, old_cert_file
+
+      unless File.exist? old_cert_path then
+        Gem::Security.write old_cert, old_cert_path
+
+        cert = Gem::Security.re_sign old_cert, @key
+
+        Gem::Security.write cert, disk_cert_path
+
+        @cert_chain = [cert]
+      end
+    end
+  end
+
+end
+