Add rspec and fix a bug in XOR in the process

lib/rex/text/xor.rb

@@ -18,8 +18,7 @@ module Rex
 
       value.each_byte do |byte|
         xor_byte = byte ^ xor_key
-        xor_byte = [xor_byte].pack('c').first
-        buf << xor_byte
+        buf << [xor_byte].pack('c')
       end
 
       buf

spec/rex/text/aes256_spec.rb

@@ -0,0 +1,55 @@
+require 'spec_helper'
+require 'securerandom'
+require 'openssl'
+
+
+describe Rex::Text do
+
+    let(:iv) {
+      SecureRandom.random_bytes(16)
+    }
+
+    let(:key) {
+      SecureRandom.random_bytes(32)
+    }
+
+    let(:value) {
+      'Hello World'
+    }
+
+  describe '#encrypt_aes256' do
+    it 'raises a CipherError exception due to a short IV' do
+      iv = SecureRandom.random_bytes(1)
+      expect { Rex::Text.encrypt_aes256(iv, key, value) }.to raise_error(OpenSSL::Cipher::CipherError)
+    end
+
+    it 'raises a CipherError exception due to a short key' do
+      key = SecureRandom.random_bytes(1)
+      expect { Rex::Text.encrypt_aes256(iv, key, value) }.to raise_error(OpenSSL::Cipher::CipherError)
+    end
+
+    it 'encrypts the string Hello World' do
+      encrypted_str = Rex::Text.encrypt_aes256(iv, key, value)
+      expect(encrypted_str).not_to eq(value)
+    end
+  end
+
+  describe '#decrypt_aes256' do
+    it 'raises a CipherError exception due to a short IV' do
+      iv = SecureRandom.random_bytes(1)
+      expect { Rex::Text.decrypt_aes256(iv, key, value) }.to raise_error(OpenSSL::Cipher::CipherError)
+    end
+
+    it 'raises a CipherError exception due to a short key' do
+      key = SecureRandom.random_bytes(1)
+      expect { Rex::Text.decrypt_aes256(iv, key, value) }.to raise_error(OpenSSL::Cipher::CipherError)
+    end
+
+    it 'decrypts the value to Hello World' do
+      encrypted_str = Rex::Text.encrypt_aes256(iv, key, value)
+      decrypted_str = Rex::Text.decrypt_aes256(iv, key, encrypted_str)
+      expect(decrypted_str).to eq(value)
+    end
+  end
+
+end

spec/rex/text/rc4_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+require 'securerandom'
+
+
+describe Rex::Text do
+
+  describe '#rc4' do
+
+    let(:key) {
+      SecureRandom.random_bytes(32)
+    }
+
+    let(:value) {
+      'Hello World'
+    }
+
+    it 'encrypts a string' do
+      expect(Rex::Text.rc4(key, value)).not_to eq(value)
+    end
+
+    it 'decrypts a string' do
+      encrypted_str = Rex::Text.rc4(key, value)
+      decrypted_str = Rex::Text.rc4(key, encrypted_str)
+      expect(decrypted_str).to eq(value)
+    end
+
+  end
+end

spec/rex/text/xor_spec.rb

@@ -0,0 +1,32 @@
+require 'spec_helper'
+
+
+describe Rex::Text do
+
+  describe '#xor' do
+
+    let(:hello_world_str) {
+      'hello world'
+    }
+
+    let(:xor_hello_world_str) {
+      "\x67\x6a\x63\x63\x60\x2f\x78\x60\x7d\x63\x6b"
+    }
+
+    it 'XORs with an integer type key' do
+      xor_key = 0x0f
+      expect(Rex::Text.xor(xor_key, hello_world_str)).to eq(xor_hello_world_str)
+    end
+
+    it 'XORs with a string type key' do
+      xor_key = "0x0f"
+      expect(Rex::Text.xor(xor_key, hello_world_str)).to eq(xor_hello_world_str)
+    end
+
+    it 'raises an ArgumentError due to an out of range key' do
+      bad_key = 0x1024
+      expect { Rex::Text.xor(bad_key, hello_world_str) }.to raise_error(ArgumentError)
+    end
+
+  end
+end