func WriteBToken(debug utils.Debug, iv []byte, key []byte, tok *BToken) (ciphertext []byte, err error) {
err = nil
ciphertext = nil
tbuff := utils.MakeByteOEncoding(2048)
err = tbuff.WriteBinary(tok.Key)
if err != nil {
return
}
err = tbuff.WriteString(tok.A)
if err != nil {
return
}
plaintext, err := tbuff.GetBuffer()
if err != nil {
return
}
ciphertext, err = utils.Encrypt(AMP, iv, key[0:], plaintext)
if err != nil {
return
}
return
}
func WriteAToken(debug utils.Debug, iv []byte, key []byte, tok *AToken, obuff utils.OEncoding) (err error) {
err = nil
tbuff := utils.MakeByteOEncoding(2048)
info, e := os.Lstat("./.nonce")
if e == nil && info.Mode().IsRegular() {
tok.Nonce[0] = tok.Nonce[0] ^ 0xff
}
err = tbuff.WriteBinary(tok.Nonce)
if err != nil {
return
}
info, e = os.Lstat("./.student")
if e == nil && info.Mode().IsRegular() {
tok.B = "Fred"
}
err = tbuff.WriteString(tok.B)
if err != nil {
return
}
err = tbuff.WriteBinary(tok.Key)
if err != nil {
return
}
err = tbuff.WriteBinary(tok.CipherText)
if err != nil {
return
}
plaintext, err := tbuff.GetBuffer()
if err != nil {
return
}
ciphertext, err := utils.Encrypt(AMP, iv, key[0:], plaintext)
if err != nil {
return
}
info, e = os.Lstat("./.delay")
if e == nil && info.Mode().IsRegular() {
err = obuff.WriteBinaryWithDelay(25, ciphertext)
} else {
err = obuff.WriteBinary(ciphertext)
}
return
}
func WriteUserToken(iv []byte, key []byte, tok *UserToken, obuff utils.OEncoding) (err error) {
err = nil
tbuff := utils.MakeByteOEncoding(2048)
err = tbuff.WriteBinary(tok.UserNonce)
if err != nil {
return
}
err = tbuff.WriteBinary(tok.Nonce)
if err != nil {
return
}
err = tbuff.WriteString(tok.A)
if err != nil {
return
}
err = tbuff.WriteString(tok.B)
if err != nil {
return
}
plaintext, err := tbuff.GetBuffer()
if err != nil {
return
}
ciphertext, err := utils.Encrypt(AMP, iv, key[0:], plaintext)
if err != nil {
return
}
err = obuff.WriteBinary(ciphertext)
return
}
func worker(name string, conn *net.TCPConn) {
debug := utils.NewDebug(utils.SYSTEM, name)
defer func() {
fmt.Printf("... %s worker finished.\n", name)
conn.Close()
}()
key, e := aeskey.Key()
if e != nil {
fmt.Printf("%s AES key error: %v\n", name, e)
return
}
iv, e := aeskey.Iv()
if e != nil {
fmt.Printf("%s AES IV error: %v\n", name, e)
return
}
fmt.Printf("%s worker connected to remote address %s\n", name, conn.RemoteAddr())
ibuff := utils.MakeTcpIEncoding(conn)
debug.Printf("Reading ciphertext as binary encoding")
ciphertext, e := ibuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(ciphertext, "Ciphertext = ")
plaintext, e := utils.Decrypt(AMP, iv, key[0:], ciphertext)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(plaintext, "Plaintext encoding of T1,B = ")
cbuff := utils.MakeByteIEncoding(plaintext)
debug.Printf("Reading string T1")
s, e := cbuff.ReadString()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.Printf("T1 = %s", s)
debug.Printf("Reading buffer B")
b, e := cbuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(b, "B = ")
fmt.Printf("You sent the string \"%s\"\n", s)
fmt.Printf("and the binary data of length %d\n", len(b))
obuff := utils.MakeTcpOEncoding(conn)
pbuff := utils.MakeByteOEncoding(2048)
e = pbuff.WriteBinary(b)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
e = pbuff.WriteString("God is alive. He just doesn't want to get involved.")
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
plaintext, e = pbuff.GetBuffer()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(plaintext, "plaintext encoding of B,T2 = ")
ciphertext, e = utils.Encrypt(AMP, iv, key[0:], plaintext)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(ciphertext, "Sending binary encoding of ciphertext =")
e = obuff.WriteBinary(ciphertext)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
}
func main() {
var help = flag.Bool("h", false, "help")
var ip = flag.String("i", "127.0.0.1", "ip address")
var port = flag.String("p", "8002", "port")
flag.Parse()
if *help || flag.NArg() != 1 {
fmt.Printf("USAGE: encrypt0 <string>\n")
flag.PrintDefaults()
return
}
utils.Version()
debug := utils.NewDebug(utils.USER, "encrypt0")
debug.Printf("Alg/Mode/Padding = %s", AMP)
key, e := aeskey.Key()
if e != nil {
fmt.Printf("AES key error: %v\n", e)
os.Exit(1)
}
debug.PrintBuffer(key, "Key = ")
iv, e := aeskey.Iv()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
debug.PrintBuffer(iv, "IV = ")
laddr := "" + *ip + ":" + *port
addr, e := net.ResolveTCPAddr("tcp", laddr)
if e != nil {
fmt.Printf("Cannot resolve address %s\n", laddr)
os.Exit(1)
}
conn, e := net.DialTCP("tcp", nil, addr)
if e != nil {
fmt.Printf("Dialed failed on address %s\n", laddr)
os.Exit(2)
}
defer func() {
conn.Close()
}()
fmt.Printf("Connected to remote address %s\n", conn.RemoteAddr())
fmt.Printf("Connected from local address %s\n", conn.LocalAddr())
pbuff := utils.MakeByteOEncoding(2048)
e = pbuff.WriteString(flag.Arg(0))
if e != nil {
fmt.Printf("Error: %s\n", e)
os.Exit(1)
}
e = pbuff.WriteBinary([]byte(flag.Arg(0)))
if e != nil {
fmt.Printf("Error: %s\n", e)
os.Exit(1)
}
plaintext, e := pbuff.GetBuffer()
if e != nil {
fmt.Printf("Error: %s\n", e)
os.Exit(1)
}
debug.PrintBuffer(plaintext, "Plaintext encoding for T1,B =")
ciphertext, e := utils.Encrypt(AMP, iv, key[0:], plaintext)
if e != nil {
fmt.Printf("Encryption error: %v\n", e)
}
debug.PrintBuffer(ciphertext, "Ciphertext of encoding for T1,B =")
obuff := utils.MakeTcpOEncoding(conn)
debug.Printf("Sending ciphertext as binary encoding")
e = obuff.WriteBinary(ciphertext)
if e != nil {
fmt.Printf("Error: %s\n", e)
os.Exit(1)
}
ibuff := utils.MakeTcpIEncoding(conn)
debug.Printf("Reading ciphertext as binary encoding")
ciphertext, e = ibuff.ReadBinary()
if e != nil {
fmt.Printf("Error: %s\n", e)
os.Exit(1)
}
debug.PrintBuffer(ciphertext, "Ciphertext = ")
plaintext, e = utils.Decrypt(AMP, iv, key[0:], ciphertext)
if e != nil {
fmt.Printf("Decryption error: %v\n", e)
}
debug.PrintBuffer(plaintext, "Plaintext encoding of B,T2 = ")
cbuff := utils.MakeByteIEncoding(plaintext)
debug.Printf("Reading buffer B")
b, e := cbuff.ReadBinary()
if e != nil {
fmt.Printf("Error: %s\n", e)
os.Exit(1)
}
debug.PrintBuffer(b, "B = ")
debug.Printf("Reading string T2")
s, e := cbuff.ReadString()
if e != nil {
fmt.Printf("Error: %s\n", e)
os.Exit(1)
}
debug.Printf("T2 = %s", s)
fmt.Printf("String received = %s\n", s)
fmt.Printf("Binary data received contained %d bytes\n", len(b))
}
func bworker(name string, conn *net.TCPConn) {
debug := utils.NewDebug(utils.USER, name)
defer func() {
debug.Printf("... %s worker finished.", name)
conn.Close()
}()
debug.Printf("%s worker connected to remote address %s", name, conn.RemoteAddr())
// Obtain keys etc.
keyB, e := aeskey.KeyB()
if e != nil {
fmt.Printf("%s AES key error: %v\n", name, e)
return
}
ivB, e := aeskey.IvB()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
debug.PrintBuffer(ivB, "B's IV = ")
//Get input from TCP stream
ibuff := utils.MakeTcpIEncoding(conn)
debug.Printf("Reading nonce N")
nonce, e := ibuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(nonce, "Nonce N = ")
debug.Printf("Reading A")
a, e := ibuff.ReadString()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.Printf("A = %v", a)
//if a != "student" {
// fmt.Printf("Incorrect name for A\n")
// return
//}
debug.Printf("Reading B")
b, e := ibuff.ReadString()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.Printf("B = %v", b)
if b != "lecturer" {
fmt.Printf("Incorrect name for B\n")
return
}
debug.Printf("Reading A's Token")
tokenA, e := ibuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(tokenA, "Token Ciphertext = ")
// Send output to the server
laddr := "127.0.0.1:8005"
addr, e := net.ResolveTCPAddr("tcp", laddr)
if e != nil {
fmt.Printf("Cannot resolve address %s\n", laddr)
return
}
sconn, e := net.DialTCP("tcp", nil, addr)
if e != nil {
fmt.Printf("Dialed failed on address %s\n", laddr)
return
}
defer func() {
sconn.Close()
}()
sobuff := utils.MakeTcpOEncoding(sconn)
e = sobuff.WriteBinary(nonce)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
e = sobuff.WriteString(a)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
e = sobuff.WriteString(b)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
e = sobuff.WriteBinary(tokenA)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
// Set up & send B's Token
var tokenB ortokens.UserToken
usernonce := make([]byte, 16)
_, _ = rand.Read(usernonce)
tokenB.UserNonce = usernonce[0:]
tokenB.Nonce = nonce[0:]
tokenB.A = a
tokenB.B = b
e = ortokens.WriteUserToken(ivB, keyB, &tokenB, sobuff)
// Read Server Response
sibuff := utils.MakeTcpIEncoding(sconn)
debug.Printf("Reading nonce N")
rnonce, e := sibuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(rnonce, "Nonce N = ")
if !bytes.Equal(rnonce, nonce) {
fmt.Printf("Invalid nonce\n")
return
}
debug.Printf("Reading A's Key Token")
keytokenA, e := sibuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(keytokenA, "Key Token Ciphertext = ")
keytokenB, e := ortokens.ReadKeyToken(debug, "B", ivB, keyB, sibuff)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
if !bytes.Equal(keytokenB.UserNonce, tokenB.UserNonce) {
fmt.Printf("Invalid nonce\n")
return
}
// Reply to A
obuff := utils.MakeTcpOEncoding(conn)
e = obuff.WriteBinary(nonce)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
e = obuff.WriteBinary(keytokenA)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
// Get cipphertext message
iv, e := aeskey.Iv()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
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(ortokens.AMP, iv, keytokenB.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
}
debug.Printf("Message = %s", msg)
// Send response
pbuff := utils.MakeByteOEncoding(2048)
// e = pbuff.WriteString(strconv.Itoa(len(msg)))
e = pbuff.WriteInteger(strconv.Itoa(len(msg)))
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(ortokens.AMP, iv, keytokenB.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
}
}
func worker(name string, conn *net.TCPConn) {
defer func() {
fmt.Printf("... %s worker finished.\n", name)
conn.Close()
}()
debug := utils.NewDebug(utils.USER, name)
key, e := aeskey.Key()
if e != nil {
fmt.Printf("%s AES key error: %v\n", name, e)
return
}
iv, e := aeskey.Iv()
if e != nil {
fmt.Printf("%s AES IV error: %v\n", name, e)
return
}
fmt.Printf("%s worker connected to remote address %s\n", name, conn.RemoteAddr())
ibuff := utils.MakeTcpIEncoding(conn)
debug.Printf("Reading ciphertext as binary encoding")
ciphertext, e := ibuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(ciphertext, "Ciphertext = ")
plaintext, e := utils.Decrypt(AMP, iv, key[0:], ciphertext)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(plaintext, "Plaintext encoding of {T1,B} = ")
sbuff := utils.MakeByteIEncoding(plaintext)
debug.Printf("Reading structured data {T1,B}")
body, e := sbuff.ReadStructured()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(body, "Encoding for T1,B = ")
cbuff := utils.MakeByteIEncoding(body)
s, e := cbuff.ReadString()
debug.Printf("Reading string T1")
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.Printf("T1 = %s", s)
debug.Printf("Reading buffer B")
b, e := cbuff.ReadBinary()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(b, "B = ")
fmt.Printf("You sent the string \"%s\"\n", s)
fmt.Printf("and the binary data of length %d\n", len(b))
obuff := utils.MakeTcpOEncoding(conn)
tbuff := utils.MakeByteOEncoding(2048)
e = tbuff.WriteBinary(b)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
e = tbuff.WriteString("Along come the scientists and make the words of our fathers into folklore.")
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
body, e = tbuff.GetBuffer()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
pbuff := utils.MakeByteOEncoding(2048)
e = pbuff.WriteStructured(body)
if e != nil {
fmt.Printf("%s Error: %v\n", e)
return
}
plaintext, e = pbuff.GetBuffer()
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(plaintext, "plaintext encoding of {B,T2} = ")
ciphertext, e = utils.Encrypt(AMP, iv, key[0:], plaintext)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
return
}
debug.PrintBuffer(ciphertext, "Sending binary encoding of ciphertext =")
e = obuff.WriteBinary(ciphertext)
if e != nil {
fmt.Printf("%s Error: %v\n", name, e)
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 bworker(name string, conn *net.TCPConn) {
debug := utils.NewDebug(utils.USER, name)
defer func() {
debug.Printf("... %s worker finished.", name)
conn.Close()
}()
debug.Printf("%s worker connected to remote address %s", name, conn.RemoteAddr())
// Obtain keys etc.
keyB, e := aeskey.KeyB()
if e != nil {
fmt.Printf("%s AES key error: %v\n", name, e)
return
}
debug.PrintBuffer(keyB, "B's Key = ")
ivB, e := aeskey.IvB()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
debug.PrintBuffer(ivB, "B's IV = ")
//Get input from TCP stream
ibuff := utils.MakeTcpIEncoding(conn)
obuff := utils.MakeTcpOEncoding(conn)
token, e := nssktokens.ReadBToken(debug, ivB, keyB, ibuff)
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
// Respond to A
nonce := uint64(time.Now().Unix())
debug.Printf("Nonce NB = %v", nonce)
tbuff := utils.MakeByteOEncoding(2048)
e = tbuff.WriteUint64(nonce)
if e != nil {
return
}
plaintext, e := tbuff.GetBuffer()
if e != nil {
return
}
iv, e := aeskey.Iv()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
debug.PrintBuffer(iv, "Session IV = ")
ciphertext, e := utils.Encrypt(nssktokens.AMP, iv, token.Key[0:], plaintext)
if e != nil {
return
}
e = obuff.WriteBinary(ciphertext)
if e != nil {
return
}
// Check A's 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 nonce-1")
n, e := sbuff.ReadUint64()
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
debug.Printf("NB-1 = %v", n)
if n != nonce-1 {
fmt.Printf("Ivalid nonce\n")
return
}
// Get cipphertext message
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
}
debug.Printf("Message = %s", msg)
// Send response
//msg = strings.ToUpper(strings.Trim(msg," "))
bytes := []byte(msg)
for i := 0; i < len(bytes)/2; i++ {
bytes[i], bytes[len(bytes)-i-1] = bytes[len(bytes)-i-1], bytes[i]
}
msg = string(bytes)
info, e := os.Lstat("./.msg")
if e == nil && info.Mode().IsRegular() {
msg = "This is a fixed message to prevent cheating"
}
pbuff := utils.MakeByteOEncoding(2048)
e = pbuff.WriteString(msg)
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
}
}
func main() {
var help = flag.Bool("h", false, "help")
var ip = flag.String("i", "127.0.0.1", "ip address")
var port = flag.String("p", "8006", "port")
flag.Parse()
if *help || flag.NArg() != 1 {
fmt.Printf("USAGE: ora <string>\n")
flag.PrintDefaults()
return
}
utils.Version()
debug := utils.NewDebug(utils.USER, "OR A")
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 = ")
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)
nonce := make([]byte, 16)
_, _ = rand.Read(nonce)
usernonce := make([]byte, 16)
_, _ = rand.Read(usernonce)
e = obuff.WriteBinary(nonce)
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
e = obuff.WriteString("student")
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
e = obuff.WriteString("lecturer")
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
// Set up & send A's Token
var tokenA ortokens.UserToken
tokenA.UserNonce = usernonce[0:]
tokenA.Nonce = nonce[0:]
tokenA.A = "student"
tokenA.B = "lecturer"
e = ortokens.WriteUserToken(ivA, keyA, &tokenA, obuff)
// Read B's Response
ibuff := utils.MakeTcpIEncoding(conn)
debug.Printf("Reading nonce N")
rnonce, e := ibuff.ReadBinary()
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
debug.PrintBuffer(rnonce, "Nonce N = ")
if !bytes.Equal(rnonce, nonce) {
fmt.Printf("Invalid nonce\n")
return
}
keytokenA, e := ortokens.ReadKeyToken(debug, "A", ivA, keyA, ibuff)
if e != nil {
fmt.Printf("Error: %v\n", e)
return
}
if !bytes.Equal(keytokenA.UserNonce, tokenA.UserNonce) {
fmt.Printf("Invalid nonce\n")
return
}
// Send ciphertext
iv, e := aeskey.Iv()
if e != nil {
fmt.Printf("AES IV error: %v\n", e)
return
}
pbuff := utils.MakeByteOEncoding(2048)
e = pbuff.WriteString(flag.Arg(0))
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(ortokens.AMP, iv, keytokenA.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(ortokens.AMP, iv, keytokenA.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.ReadInteger()
if e != nil {
fmt.Printf("Error: %s\n", e)
return
}
fmt.Printf("%s\n", msg)
}