PGNp9Lm1

1class SecretData < ActiveRecord::Base
2  mysecret = "mylittlesecret"
3
4  attr_encrypted :data1, :key=>mysecret, :algorithm => "aes-256-cbc"
5  attr_encrypted :data2, :key=>mysecret, :algorithm => "aes-256-cbc"
6
7  ...
8end
9	
10cyE3jDkKc99GVB8TiUlBxQ==
11sqcbOnBTl6yy3wwjkl0qhA==
12	
13echo cyE3jDkKc99GVB8TiUlBxQ== | openssl aes-256-cbc -a -d   (and type "mylittlesecret" as the password)
14	
15Key key = generateKey();
16Cipher c = Cipher.getInstance(ALGO);
17c.init(Cipher.DECRYPT_MODE, key);
18byte[] decordedValue = new BASE64Decoder().decodeBuffer(encryptedData);
19byte[] decValue = c.doFinal(decordedValue);
20String decryptedValue = new String(decValue);
21	
22irb(main):069:0> Encryptor.decrypt(Base64.decode64("cyE3jDkKc99GVB8TiUlBxQ=="), ,key=>'mylittlesecret')
23=> "data1-value"
24	
25public static byte[][] EVP_BytesToKey(int key_len, int iv_len, MessageDigest md,
26            byte[] salt, byte[] data, int count) {
27        byte[][] both = new byte[2][];
28        byte[] key = new byte[key_len];
29        int key_ix = 0;
30        byte[] iv = new byte[iv_len];
31        int iv_ix = 0;
32        both[0] = key;
33        both[1] = iv;
34        byte[] md_buf = null;
35        int nkey = key_len;
36        int niv = iv_len;
37        int i = 0;
38        if (data == null) {
39            return both;
40        }
41        int addmd = 0;
42        for (;;) {
43            md.reset();
44            if (addmd++ > 0) {
45                md.update(md_buf);
46            }
47            md.update(data);
48            if (null != salt) {
49                md.update(salt, 0, 8);
50            }
51            md_buf = md.digest();
52            for (i = 1; i < count; i++) {
53                md.reset();
54                md.update(md_buf);
55                md_buf = md.digest();
56            }
57            i = 0;
58            if (nkey > 0) {
59                for (;;) {
60                    if (nkey == 0)
61                        break;
62                    if (i == md_buf.length)
63                        break;
64                    key[key_ix++] = md_buf[i];
65                    nkey--;
66                    i++;
67                }
68            }
69            if (niv > 0 && i != md_buf.length) {
70                for (;;) {
71                    if (niv == 0)
72                        break;
73                    if (i == md_buf.length)
74                        break;
75                    iv[iv_ix++] = md_buf[i];
76                    niv--;
77                    i++;
78                }
79            }
80            if (nkey == 0 && niv == 0) {
81                break;
82            }
83        }
84        for (i = 0; i < md_buf.length; i++) {
85            md_buf[i] = 0;
86        }
87        return both;
88    }
89	
90def self.encrypt(options)
91
92   plaintext = options[:value]
93   return true if plaintext.blank?
94
95   cipher = OpenSSL::Cipher::Cipher.new(@@cipher_type)
96   cipher.encrypt
97
98   iv = cipher.random_iv
99   salt = (0 ... @@salt_length).map{65.+(rand(25)).chr}.join   # random salt
100   key = OpenSSL::PKCS5.pbkdf2_hmac_sha1(@@password, salt, @@pkbdf_num_iters, cipher.key_len)
101
102   cipher.key = key
103   cipher.iv = iv
104
105   enc_data = cipher.update(plaintext)
106   enc_data << cipher.final
107
108   final_data = salt << iv << enc_data
109   Base64.strict_encode64(final_data)
110end
111
112def self.decrypt(options)
113
114   ciphertext = options[:value]
115   return true if ciphertext.blank?
116
117
118   cipher = OpenSSL::Cipher::Cipher.new(@@cipher_type)
119   cipher.decrypt
120
121   cipher_data = Base64.decode64(ciphertext)
122
123   salt = cipher_data[0 .. @@salt_length-1]
124   iv = cipher_data[@@salt_length .. @@salt_length+cipher.iv_len]
125   enc_data = cipher_data[@@salt_length+cipher.iv_len .. -1]  # the rest
126
127   key = OpenSSL::PKCS5.pbkdf2_hmac_sha1(@@password, salt, @@pkbdf_num_iters, cipher.key_len)
128
129   cipher.key = key
130   cipher.iv = iv
131
132   plaintext = cipher.update(enc_data)
133   plaintext << cipher.final
134
135   plaintext
136  end
137	
138public String decrypt(String ciphertext) throws Exception {
139    byte[] crypt = Base64.decodeBase64(ciphertext);
140
141    // parse the encrypted data and get salt and IV
142    byte[] salt = Arrays.copyOfRange(crypt, 0, saltLength);
143    byte[] iv = Arrays.copyOfRange(crypt, saltLength, saltLength + ivLength);
144    byte[] encryptedData = Arrays.copyOfRange(crypt, saltLength + ivLength, crypt.length);
145
146    // generate key from salt and password  
147    SecretKeyFactory f = SecretKeyFactory.getInstance(secretKeyName);
148    KeySpec ks = new PBEKeySpec(password.toCharArray(), salt, pbkdfNumIters, keyLength);
149    SecretKey s = f.generateSecret(ks);
150    Key keySpec = new SecretKeySpec(s.getEncoded(),"AES");
151
152    // initialize the cipher object with the key and IV
153    Cipher cipher = Cipher.getInstance(cipherAlgo);
154    IvParameterSpec ivSpec = new IvParameterSpec(iv);
155    cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
156
157    // decrypt
158    byte[] decBytes = cipher.doFinal(encryptedData);
159
160    return new String(decBytes);
161}