Go

Duplicate SQL Server ENCRYPTBYPASSPHRASE

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Demonstrates how to duplicate SQL Server's ENCRYPTBYPASSPHRASE. Go

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // For SQL Server 2008 - SQL Server 2016 we must use TripleDES with SHA1
    // For SQL Server 2017 and later, use AES256 / SHA256.

    password := "tEst1234"
    encryptedHex_v1 := "0x010000001E8E7DCDBD4061B951999E25D18445D2305474D2D71EEE98A241C755246F58AB"

    // Here's an encrypted string using AES256/SHA256
    encryptedHex_v2 := "0x02000000FFE880C0354780481E64EF25B6197A02E2A854A4BA9D8D9BDDFDAB27EB56537ABDA0B1D9C4D1050C91B313550DECF429"

    sbEncHex := chilkat.NewStringBuilder()
    sbEncHex.Append(encryptedHex_v1)

    // If present, we don't want the leading "0x"
    if sbEncHex.StartsWith("0x",false) == true {
        sbEncHex.RemoveCharsAt(0,2)
    }

    crypt := chilkat.NewCrypt2()
    crypt.SetEncodingMode("hex")

    // The encrypted hex string will begin with either 01000000 or 02000000
    // version 1 is produced by SQL Server 2008 to SQL Server 2016, and we must use TripleDES with SHA1
    // version 2 is for SQL Server 2017 and later, and uses AES256 / SHA256.
    v1 := sbEncHex.StartsWith("01",false)

    ivLen := 0
    var hashAlg string

    if v1 == true {
        crypt.SetCryptAlgorithm("3des")
        crypt.SetCipherMode("cbc")
        crypt.SetKeyLength(168)
        ivLen = 8
        hashAlg = "sha1"
    } else {
        crypt.SetCryptAlgorithm("aes")
        crypt.SetCipherMode("cbc")
        crypt.SetKeyLength(256)
        ivLen = 16
        hashAlg = "sha256"
    }

    // Remove the SQL Server version info (i.e. the "01000000")
    sbEncHex.RemoveCharsAt(0,8)

    // Get the IV part of the sbEncHex, and also remove it from the StringBuilder.
    ivHex := sbEncHex.GetRange(0,ivLen * 2,true)
    fmt.Println("IV = ", *ivHex)
    crypt.SetEncodedIV(*ivHex,"hex")

    sbPassword := chilkat.NewStringBuilder()
    sbPassword.Append(password)
    pwd_hash := sbPassword.GetHash(hashAlg,"hex","utf-16")
    sbKey := chilkat.NewStringBuilder()
    sbKey.Append(*pwd_hash)
    if v1 == true {
        // For v1, we only want the 1st 16 bytes of the 20 byte hash.
        // (remember, the hex encoding uses 2 chars per byte, so we remove the last 8 chars)
        sbKey.Shorten(8)
    }

    fmt.Println("crypt key: ", *sbKey.GetAsString())

    crypt.SetEncodedKey(*sbKey.GetAsString(),"hex")

    // Decrypt
    bd := chilkat.NewBinData()
    bd.AppendEncoded(*sbEncHex.GetAsString(),"hex")
    crypt.DecryptBd(bd)

    // The result is composed of a header of 8 bytes which we can discard.
    // The remainder is the decrypted text.

    // The header we are discarding is composed of:
    // Bytes 0-3: Magic number equal to 0DF0ADBA
    // Bytes 4-5: Number of integrity bytes, which is 0 unless an authenticator is used. We're assuming no authenticator is used.
    // Bytes 6-7: Number of plain-text bytes. We really don't need this because the CBC padding takes care of it.

    // Therefore, just return the data after the 1st 8 bytes.
    // Assuming the encrypted string was utf-8 text...
    bd.RemoveChunk(0,8)
    plainText := bd.GetString("utf-8")
    fmt.Println("decrypted plain text: ", *plainText)

    // The output:

    // IV = 1E8E7DCDBD4061B9
    // crypt key: 710B9C2E61ACCC9570D4112203BD9738
    // decrypted plain text: Hello world.

    // ------------------------------------------------------------------------------------------
    // To encrypt, do the reverse...

    // Let's do v1 with TripleDES with SHA1

    encryptor := chilkat.NewCrypt2()
    encryptor.SetEncodingMode("hex")

    encryptor.SetCryptAlgorithm("3des")
    encryptor.SetCipherMode("cbc")
    encryptor.SetKeyLength(168)

    // Generate a random 8-byte IV
    prng := chilkat.NewPrng()
    ivHex = prng.GenRandom(8,"hex")
    encryptor.SetEncodedIV(*ivHex,"hex")

    // The binary password is generated the same as above.
    // We'll use the same password (and same binary password)
    encryptor.SetEncodedKey(*sbKey.GetAsString(),"hex")

    plainTextLen := 8
    *plainText = "ABCD1234"

    // Encrypt the header + the plain-text.
    bdData := chilkat.NewBinData()
    bdData.AppendEncoded("0DF0ADBA","hex")
    bdData.AppendEncoded("0000","hex")
    bdData.AppendInt2(plainTextLen,true)
    fmt.Println("header: ", *bdData.GetEncoded("hex"))
    bdData.AppendString(*plainText,"utf-8")
    encryptor.EncryptBd(bdData)

    // Compose the result..
    sbEnc := chilkat.NewStringBuilder()
    sbEnc.Append("0x01000000")
    sbEnc.Append(*ivHex)
    sbEnc.Append(*bdData.GetEncoded("hex"))

    fmt.Println("result: ", *sbEnc.GetAsString())

    sbEncHex.DisposeStringBuilder()
    crypt.DisposeCrypt2()
    sbPassword.DisposeStringBuilder()
    sbKey.DisposeStringBuilder()
    bd.DisposeBinData()
    encryptor.DisposeCrypt2()
    prng.DisposePrng()
    bdData.DisposeBinData()
    sbEnc.DisposeStringBuilder()