func ReadAToken(debug utils.Debug, iv []byte, key []byte, ibuff utils.IEncoding) (tok AToken, err error) {
err = nil
debug.Printf("Reading A's token")
ciphertext, err := ibuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(ciphertext, "Token Ciphertext = ")
t, err := utils.Decrypt(AMP, iv, key[0:], ciphertext)
if err != nil {
return
}
debug.PrintBuffer(t, "Token Plaintext = ")
sbuff := utils.MakeByteIEncoding(t)
debug.Printf("Reading nonce N")
nonce, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(nonce, "Nonce N = ")
tok.Nonce = nonce[0:]
debug.Printf("Reading B")
b, err := sbuff.ReadString()
if err != nil {
return
}
debug.Printf("B = %v", b)
tok.B = b
debug.Printf("Reading session key")
skey, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(skey, "Session Key = ")
tok.Key = skey[0:]
debug.Printf("Reading ciphertext of B's token")
ct, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(ct, "Ciphertext of B's token = ")
tok.CipherText = ct[0:]
return
}
func ReadBToken(debug utils.Debug, iv []byte, key []byte, ibuff utils.IEncoding) (tok BToken, err error) {
err = nil
debug.Printf("Reading B's token")
ciphertext, err := ibuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(ciphertext, "Token Ciphertext = ")
t, err := utils.Decrypt(AMP, iv, key[0:], ciphertext)
if err != nil {
return
}
debug.PrintBuffer(t, "Token Plaintext = ")
sbuff := utils.MakeByteIEncoding(t)
debug.Printf("Reading session key")
skey, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(skey, "Session Key = ")
tok.Key = skey[0:]
debug.Printf("Reading A")
a, err := sbuff.ReadString()
if err != nil {
return
}
debug.Printf("A = %v", a)
tok.A = a
return
}
func contact_S(debug utils.Debug, ip string, port string) (token nssktokens.AToken, e error) {
e = nil
keyA, e := aeskey.KeyA()
if e != nil {
fmt.Printf("AES key error: %v\n", e)
return
}
debug.PrintBuffer(keyA, "A's Key = ")
ivA, e := aeskey.IvA()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
debug.PrintBuffer(ivA, "A's IV = ")
nonce := make([]byte, 16)
_, _ = rand.Read(nonce)
debug.PrintBuffer(nonce, "Nonce N = ")
// connect to the server
laddr := "" + ip + ":" + port
addr, e := net.ResolveTCPAddr("tcp", laddr)
if e != nil {
fmt.Printf("Cannot resolve address %s\n", laddr)
return
}
conn, e := net.DialTCP("tcp", nil, addr)
if e != nil {
fmt.Printf("Dialed failed on address %s\n", laddr)
return
}
defer func() {
conn.Close()
}()
fmt.Printf("Connected to remote address %s\n", conn.RemoteAddr())
fmt.Printf("Connected from local address %s\n", conn.LocalAddr())
obuff := utils.MakeTcpOEncoding(conn)
e = obuff.WriteString(a)
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
e = obuff.WriteString(b)
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
e = obuff.WriteBinary(nonce)
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
// Read S's Response
ibuff := utils.MakeTcpIEncoding(conn)
token, e = nssktokens.ReadAToken(debug, ivA, keyA, ibuff)
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
if !bytes.Equal(token.Nonce, nonce) {
fmt.Printf("Invalid nonce\n")
return
}
if token.B != b {
fmt.Printf("Invalid B in token\n")
return
}
return
}
func contact_B(debug utils.Debug, ip string, port string, token nssktokens.AToken, message string) (e error) {
e = nil
// connect to the server
laddr := "" + ip + ":" + port
addr, e := net.ResolveTCPAddr("tcp", laddr)
if e != nil {
fmt.Printf("Cannot resolve address %s\n", laddr)
return
}
conn, e := net.DialTCP("tcp", nil, addr)
if e != nil {
fmt.Printf("Dialed failed on address %s\n", laddr)
return
}
defer func() {
conn.Close()
}()
fmt.Printf("Connected to remote address %s\n", conn.RemoteAddr())
fmt.Printf("Connected from local address %s\n", conn.LocalAddr())
obuff := utils.MakeTcpOEncoding(conn)
e = obuff.WriteBinary(token.CipherText)
if e != nil {
fmt.Printf("error: %v\n", e)
return
}
// Read B's Response
iv, e := aeskey.Iv()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
debug.PrintBuffer(iv, "Session IV = ")
ibuff := utils.MakeTcpIEncoding(conn)
debug.Printf("Reading B's response")
ciphertext, e := ibuff.ReadBinary()
if e != nil {
return
}
debug.PrintBuffer(ciphertext, "Ciphertext = ")
t, e := utils.Decrypt(nssktokens.AMP, iv, token.Key[0:], ciphertext)
if e != nil {
return
}
debug.PrintBuffer(t, "Plaintext = ")
sbuff := utils.MakeByteIEncoding(t)
debug.Printf("Reading nonce NB")
nonce, e := sbuff.ReadUint64()
if e != nil {
return
}
debug.Printf("Nonce NB = %v", nonce)
// Respond to B
tbuff := utils.MakeByteOEncoding(2048)
e = tbuff.WriteUint64(nonce - 1)
if e != nil {
return
}
plaintext, e := tbuff.GetBuffer()
if e != nil {
return
}
ciphertext, e = utils.Encrypt(nssktokens.AMP, iv, token.Key[0:], plaintext)
if e != nil {
return
}
e = obuff.WriteBinary(ciphertext)
if e != nil {
return
}
// Send ciphertext
pbuff := utils.MakeByteOEncoding(2048)
e = pbuff.WriteString(message)
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
plaintext, e = pbuff.GetBuffer()
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
ciphertext, e = utils.Encrypt(nssktokens.AMP, iv, token.Key[0:], plaintext)
if e != nil {
fmt.Printf("Encryption error: %v\n", e)
return
}
e = obuff.WriteBinary(ciphertext)
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
// Get cipphertext response
debug.Printf("Reading protocol message ciphertext")
ciphertext, e = ibuff.ReadBinary()
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
debug.PrintBuffer(ciphertext, "Ciphertext = ")
debug.Printf("Decrypting ciphertext")
t, e = utils.Decrypt(nssktokens.AMP, iv, token.Key[0:], ciphertext)
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
debug.PrintBuffer(t, "Plaintext = ")
sbuff = utils.MakeByteIEncoding(t)
debug.Printf("Reading message")
msg, e := sbuff.ReadString()
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
fmt.Printf("%s\n", msg)
return
}
func ReadUserToken(debug utils.Debug, user string, iv []byte, key []byte, ibuff utils.IEncoding) (tok UserToken, err error) {
err = nil
debug.Printf("Reading %s's token", user)
ciphertext, err := ibuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(ciphertext, "Token Ciphertext = ")
t, err := utils.Decrypt(AMP, iv, key[0:], ciphertext)
if err != nil {
return
}
debug.PrintBuffer(t, "Token Plaintext = ")
sbuff := utils.MakeByteIEncoding(t)
debug.Printf("Reading nonce N%s", user)
usernonce, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(usernonce, "Nonce = ")
tok.UserNonce = usernonce[0:]
debug.Printf("Reading nonce N")
nonce, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(nonce, "Nonce N = ")
tok.Nonce = nonce[0:]
debug.Printf("Reading A")
a, err := sbuff.ReadString()
if err != nil {
return
}
debug.Printf("A = %v", a)
tok.A = a
debug.Printf("Reading B")
b, err := sbuff.ReadString()
if err != nil {
return
}
debug.Printf("B = %v", b)
tok.B = b
return
}
func ReadKeyToken(debug utils.Debug, user string, iv []byte, key []byte, ibuff utils.IEncoding) (tok KeyToken, err error) {
err = nil
debug.Printf("Reading %s's key token", user)
ciphertext, err := ibuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(ciphertext, "Key Token Ciphertext = ")
t, err := utils.Decrypt(AMP, iv, key[0:], ciphertext)
if err != nil {
return
}
debug.PrintBuffer(t, "Key Token Plaintext = ")
sbuff := utils.MakeByteIEncoding(t)
debug.Printf("Reading nonce N%s", user)
usernonce, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(usernonce, "Nonce = ")
tok.UserNonce = usernonce[0:]
debug.Printf("Reading session key")
skey, err := sbuff.ReadBinary()
if err != nil {
return
}
debug.PrintBuffer(skey, "Session Key = ")
tok.Key = skey[0:]
return
}
