mirror of https://github.com/tidwall/tile38.git
59 lines
2.0 KiB
Go
59 lines
2.0 KiB
Go
package rfc3962
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"encoding/hex"
|
|
"errors"
|
|
|
|
"github.com/jcmturner/gofork/x/crypto/pbkdf2"
|
|
"gopkg.in/jcmturner/gokrb5.v7/crypto/etype"
|
|
)
|
|
|
|
const (
|
|
s2kParamsZero = 4294967296
|
|
)
|
|
|
|
// StringToKey returns a key derived from the string provided according to the definition in RFC 3961.
|
|
func StringToKey(secret, salt, s2kparams string, e etype.EType) ([]byte, error) {
|
|
i, err := S2KparamsToItertions(s2kparams)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return StringToKeyIter(secret, salt, i, e)
|
|
}
|
|
|
|
// StringToPBKDF2 generates an encryption key from a pass phrase and salt string using the PBKDF2 function from PKCS #5 v2.0
|
|
func StringToPBKDF2(secret, salt string, iterations int64, e etype.EType) []byte {
|
|
return pbkdf2.Key64([]byte(secret), []byte(salt), iterations, int64(e.GetKeyByteSize()), e.GetHashFunc())
|
|
}
|
|
|
|
// StringToKeyIter returns a key derived from the string provided according to the definition in RFC 3961.
|
|
func StringToKeyIter(secret, salt string, iterations int64, e etype.EType) ([]byte, error) {
|
|
tkey := e.RandomToKey(StringToPBKDF2(secret, salt, iterations, e))
|
|
return e.DeriveKey(tkey, []byte("kerberos"))
|
|
}
|
|
|
|
// S2KparamsToItertions converts the string representation of iterations to an integer
|
|
func S2KparamsToItertions(s2kparams string) (int64, error) {
|
|
//process s2kparams string
|
|
//The parameter string is four octets indicating an unsigned
|
|
//number in big-endian order. This is the number of iterations to be
|
|
//performed. If the value is 00 00 00 00, the number of iterations to
|
|
//be performed is 4,294,967,296 (2**32).
|
|
var i uint32
|
|
if len(s2kparams) != 8 {
|
|
return int64(s2kParamsZero), errors.New("invalid s2kparams length")
|
|
}
|
|
b, err := hex.DecodeString(s2kparams)
|
|
if err != nil {
|
|
return int64(s2kParamsZero), errors.New("invalid s2kparams, cannot decode string to bytes")
|
|
}
|
|
i = binary.BigEndian.Uint32(b)
|
|
//buf := bytes.NewBuffer(b)
|
|
//err = binary.Read(buf, binary.BigEndian, &i)
|
|
if err != nil {
|
|
return int64(s2kParamsZero), errors.New("invalid s2kparams, cannot convert to big endian int32")
|
|
}
|
|
return int64(i), nil
|
|
}
|