crypto

Documentation

Overview

Package crypto includes common cryptography helpers.

They typically make using the stdlib functions more ergonomic, and do not seek to invent new methods for encrypting or decrypting data.

Index

• Constants
• func CreateIntKey(keySize int) (string, error)
• func CreateKey(keySize int) ([]byte, error)
• func CreateKeyBase64String(keySize int) (string, error)
• func CreateKeyString(keySize int) (string, error)
• func Decrypt(key, cipherText []byte) ([]byte, error)
• func Encrypt(key, plainText []byte) ([]byte, error)
• func HMAC256(key, plainText []byte) []byte
• func HMAC512(key, plainText []byte) []byte
• func HashPassword(password string) (string, error)
• func MustCreateKey(keySize int) []byte
• func MustCreateKeyBase64String(keySize int) string
• func MustCreateKeyString(keySize int) string
• func ParseKey(key string) ([]byte, error)
• func PasswordMatchesHash(password string, hash string) bool
• type StreamDecrypter
  • func NewStreamDecrypter(encKey, macKey []byte, meta StreamMeta, cipherText io.Reader) (*StreamDecrypter, error)
  • func (s *StreamDecrypter) Authenticate() error
  • func (s *StreamDecrypter) Read(p []byte) (int, error)
• type StreamEncrypter
  • func NewStreamEncrypter(encKey, macKey []byte, plainText io.Reader) (*StreamEncrypter, error)
  • func (s *StreamEncrypter) Meta() StreamMeta
  • func (s *StreamEncrypter) Read(p []byte) (int, error)
• type StreamMeta

Constants

const (
	// DefaultKeySize is the size of keys to generate for client use.
	DefaultKeySize = 32
	// KeyVersionSize is the size of the key version prefix.
	KeyVersionSize = (4 + 2 + 2 + 1) // YYYY + MM + DD + :
	// IVSize is the size of the IV prefix.
	IVSize = aes.BlockSize
	// HashSize is the size of the hash prefix.
	HashSize = 32 // reasons.
)

Important constants.

Functions

func CreateIntKey

func CreateIntKey(keySize int) (string, error)

CreateIntKey creates an integer key of the specified length, return an error if it fails.

func CreateKey

func CreateKey(keySize int) ([]byte, error)

CreateKey creates a key of a given size by reading that much data off the crypto/rand reader.

func CreateKeyBase64String

func CreateKeyBase64String(keySize int) (string, error)

CreateKeyBase64String generates a new key and returns it as a base64 std encoding string.

func CreateKeyString

func CreateKeyString(keySize int) (string, error)

CreateKeyString generates a new key and returns it as a hex string.

func Decrypt

func Decrypt(key, cipherText []byte) ([]byte, error)

Decrypt decrypts data with the given key.

func Encrypt

func Encrypt(key, plainText []byte) ([]byte, error)

Encrypt encrypts data with the given key.

func HMAC256

func HMAC256(key, plainText []byte) []byte

HMAC256 sha256 hashes data with the given key.

func HMAC512

func HMAC512(key, plainText []byte) []byte

HMAC512 sha512 hashes data with the given key.

func HashPassword

func HashPassword(password string) (string, error)

HashPassword uses bcrypt to generate a salted hash for the provided password

func MustCreateKey

func MustCreateKey(keySize int) []byte

MustCreateKey creates a key, if an error is returned, it panics.

func MustCreateKeyBase64String

func MustCreateKeyBase64String(keySize int) string

MustCreateKeyBase64String generates a new key and returns it as a base64 std encoding string.

func MustCreateKeyString

func MustCreateKeyString(keySize int) string

MustCreateKeyString generates a new key and returns it as a hex string.

func ParseKey

func ParseKey(key string) ([]byte, error)

ParseKey parses a key from a string.

func PasswordMatchesHash

func PasswordMatchesHash(password string, hash string) bool

PasswordMatchesHash checks whether the provided password matches the provided hash

Types

type StreamDecrypter

type StreamDecrypter struct {
	Source io.Reader
	Block  cipher.Block
	Stream cipher.Stream
	Mac    hash.Hash
	Meta   StreamMeta
}

StreamDecrypter is a decrypter for a stream of data with authentication

func NewStreamDecrypter

func NewStreamDecrypter(encKey, macKey []byte, meta StreamMeta, cipherText io.Reader) (*StreamDecrypter, error)

NewStreamDecrypter creates a new stream decrypter

func (*StreamDecrypter) Authenticate

func (s *StreamDecrypter) Authenticate() error

Authenticate verifys that the hash of the stream is correct. This should only be called after processing is finished

func (*StreamDecrypter) Read

func (s *StreamDecrypter) Read(p []byte) (int, error)

Read reads bytes from the underlying reader and then decrypts them

type StreamEncrypter

type StreamEncrypter struct {
	Source io.Reader
	Block  cipher.Block
	Stream cipher.Stream
	Mac    hash.Hash
	IV     []byte
}

StreamEncrypter is an encrypter for a stream of data with authentication

func NewStreamEncrypter

func NewStreamEncrypter(encKey, macKey []byte, plainText io.Reader) (*StreamEncrypter, error)

NewStreamEncrypter creates a new stream encrypter

func (*StreamEncrypter) Meta

func (s *StreamEncrypter) Meta() StreamMeta

Meta returns the encrypted stream metadata for use in decrypting. This should only be called after the stream is finished

func (*StreamEncrypter) Read

func (s *StreamEncrypter) Read(p []byte) (int, error)

Read encrypts the bytes of the inner reader and places them into p

type StreamMeta

type StreamMeta struct {
	// IV is the initial value for the crypto function
	IV []byte
	// Hash is the sha256 hmac of the stream
	Hash []byte
}

StreamMeta is metadata about an encrypted stream