blob: 45e439a434e3d22209f57852d267b57b01759354 [file] [log] [blame]
package crypto
import (
// RFC 3962
// Aes256CtsHmacSha96 implements Kerberos encryption type aes256-cts-hmac-sha1-96
type Aes256CtsHmacSha96 struct {
// GetETypeID returns the EType ID number.
func (e Aes256CtsHmacSha96) GetETypeID() int32 {
return etypeID.AES256_CTS_HMAC_SHA1_96
// GetHashID returns the checksum type ID number.
func (e Aes256CtsHmacSha96) GetHashID() int32 {
return chksumtype.HMAC_SHA1_96_AES256
// GetKeyByteSize returns the number of bytes for key of this etype.
func (e Aes256CtsHmacSha96) GetKeyByteSize() int {
return 256 / 8
// GetKeySeedBitLength returns the number of bits for the seed for key generation.
func (e Aes256CtsHmacSha96) GetKeySeedBitLength() int {
return e.GetKeyByteSize() * 8
// GetHashFunc returns the hash function for this etype.
func (e Aes256CtsHmacSha96) GetHashFunc() func() hash.Hash {
return sha1.New
// GetMessageBlockByteSize returns the block size for the etype's messages.
func (e Aes256CtsHmacSha96) GetMessageBlockByteSize() int {
return 1
// GetDefaultStringToKeyParams returns the default key derivation parameters in string form.
func (e Aes256CtsHmacSha96) GetDefaultStringToKeyParams() string {
return "00001000"
// GetConfounderByteSize returns the byte count for confounder to be used during cryptographic operations.
func (e Aes256CtsHmacSha96) GetConfounderByteSize() int {
return aes.BlockSize
// GetHMACBitLength returns the bit count size of the integrity hash.
func (e Aes256CtsHmacSha96) GetHMACBitLength() int {
return 96
// GetCypherBlockBitLength returns the bit count size of the cypher block.
func (e Aes256CtsHmacSha96) GetCypherBlockBitLength() int {
return aes.BlockSize * 8
// StringToKey returns a key derived from the string provided.
func (e Aes256CtsHmacSha96) StringToKey(secret string, salt string, s2kparams string) ([]byte, error) {
return rfc3962.StringToKey(secret, salt, s2kparams, e)
// RandomToKey returns a key from the bytes provided.
func (e Aes256CtsHmacSha96) RandomToKey(b []byte) []byte {
return rfc3961.RandomToKey(b)
// EncryptData encrypts the data provided.
func (e Aes256CtsHmacSha96) EncryptData(key, data []byte) ([]byte, []byte, error) {
return rfc3962.EncryptData(key, data, e)
// EncryptMessage encrypts the message provided and concatenates it with the integrity hash to create an encrypted message.
func (e Aes256CtsHmacSha96) EncryptMessage(key, message []byte, usage uint32) ([]byte, []byte, error) {
return rfc3962.EncryptMessage(key, message, usage, e)
// DecryptData decrypts the data provided.
func (e Aes256CtsHmacSha96) DecryptData(key, data []byte) ([]byte, error) {
return rfc3962.DecryptData(key, data, e)
// DecryptMessage decrypts the message provided and verifies the integrity of the message.
func (e Aes256CtsHmacSha96) DecryptMessage(key, ciphertext []byte, usage uint32) ([]byte, error) {
return rfc3962.DecryptMessage(key, ciphertext, usage, e)
// DeriveKey derives a key from the protocol key based on the usage value.
func (e Aes256CtsHmacSha96) DeriveKey(protocolKey, usage []byte) ([]byte, error) {
return rfc3961.DeriveKey(protocolKey, usage, e)
// DeriveRandom generates data needed for key generation.
func (e Aes256CtsHmacSha96) DeriveRandom(protocolKey, usage []byte) ([]byte, error) {
return rfc3961.DeriveRandom(protocolKey, usage, e)
// VerifyIntegrity checks the integrity of the plaintext message.
func (e Aes256CtsHmacSha96) VerifyIntegrity(protocolKey, ct, pt []byte, usage uint32) bool {
return rfc3961.VerifyIntegrity(protocolKey, ct, pt, usage, e)
// GetChecksumHash returns a keyed checksum hash of the bytes provided.
func (e Aes256CtsHmacSha96) GetChecksumHash(protocolKey, data []byte, usage uint32) ([]byte, error) {
return common.GetHash(data, protocolKey, common.GetUsageKc(usage), e)
// VerifyChecksum compares the checksum of the message bytes is the same as the checksum provided.
func (e Aes256CtsHmacSha96) VerifyChecksum(protocolKey, data, chksum []byte, usage uint32) bool {
c, err := e.GetChecksumHash(protocolKey, data, usage)
if err != nil {
return false
return hmac.Equal(chksum, c)