Documentation
¶
Overview ¶
Package ff3 implements the FF3 format-preserving encryption algorithm/scheme
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrStringNotInRadix is returned if input or intermediate strings cannot be parsed in the given radix ErrStringNotInRadix = errors.New("string is not within base/radix") // ErrTweakLengthInvalid is returned if the tweak length is not 8 bytes ErrTweakLengthInvalid = errors.New("tweak must be 8 bytes, or 64 bits") )
Functions ¶
This section is empty.
Types ¶
type Cipher ¶
type Cipher struct {
// contains filtered or unexported fields
}
A Cipher is an instance of the FF3 mode of format preserving encryption using a particular key, radix, and tweak
func NewCipher ¶
NewCipher initializes a new FF3 Cipher for encryption or decryption use based on the radix, key and tweak parameters.
func (Cipher) Decrypt ¶
Decrypt decrypts the string X over the current FF3 parameters and returns the plaintext of the same length and format
Example ¶
Note: panic(err) is just used for example purposes.
// Key and tweak should be byte arrays. Put your key and tweak here.
// To make it easier for demo purposes, decode from a hex string here.
key, err := hex.DecodeString("EF4359D8D580AA4F7F036D6F04FC6A94")
if err != nil {
panic(err)
}
tweak, err := hex.DecodeString("D8E7920AFA330A73")
if err != nil {
panic(err)
}
// Create a new FF3 cipher "object"
// 10 is the radix/base
FF3, err := NewCipher(10, key, tweak)
if err != nil {
panic(err)
}
ciphertext := "750918814058654607"
plaintext, err := FF3.Decrypt(ciphertext)
if err != nil {
panic(err)
}
fmt.Println(plaintext)
Output: 890121234567890000
func (Cipher) DecryptWithTweak ¶ added in v1.2.0
DecryptWithTweak is the same as Decrypt except it uses the tweak from the parameter rather than the current Cipher's tweak This allows you to re-use a single Cipher (for a given key) and simply override the tweak for each unique data input, which is a practical use-case of FPE for things like credit card numbers.
func (Cipher) Encrypt ¶
Encrypt encrypts the string X over the current FF3 parameters and returns the ciphertext of the same length and format
Example ¶
Note: panic(err) is just used for example purposes.
// Key and tweak should be byte arrays. Put your key and tweak here.
// To make it easier for demo purposes, decode from a hex string here.
key, err := hex.DecodeString("EF4359D8D580AA4F7F036D6F04FC6A94")
if err != nil {
panic(err)
}
tweak, err := hex.DecodeString("D8E7920AFA330A73")
if err != nil {
panic(err)
}
// Create a new FF3 cipher "object"
// 10 is the radix/base
FF3, err := NewCipher(10, key, tweak)
if err != nil {
panic(err)
}
original := "890121234567890000"
// Call the encryption function on an example test vector
ciphertext, err := FF3.Encrypt(original)
if err != nil {
panic(err)
}
fmt.Println(ciphertext)
Output: 750918814058654607
func (Cipher) EncryptWithTweak ¶ added in v1.2.0
EncryptWithTweak is the same as Encrypt except it uses the tweak from the parameter rather than the current Cipher's tweak This allows you to re-use a single Cipher (for a given key) and simply override the tweak for each unique data input, which is a practical use-case of FPE for things like credit card numbers.
Source Files