func main() {
{
// testing that crypto works back and forth
t := []byte("some secret stuff AAAA")
ct := make([]byte, len(t))
MTEncrypt(0, ct, t)
t2 := make([]byte, len(t))
MTEncrypt(0, t2, ct)
fmt.Println(bytes.Equal(t, t2))
}
{
// generate random bytes with AAA's appended
t := util.RandBytes(int(util.RandByte()))
knownText := "AAAAAAAAAAAAA"
t = append(t, []byte(knownText)...)
ct := make([]byte, len(t))
MTEncrypt(int(util.RandByte())*int(util.RandByte()), ct, t)
for i := 0; i < 0xFFFF; i++ {
z := make([]byte, len(ct))
MTEncrypt(i, z, ct)
if string(z[len(z)-len(knownText):]) == knownText {
fmt.Println("Found the key:", i)
break
}
}
}
{
// generate "random" "password reset token"
mt := util.NewMT19337(uint64(time.Now().Unix()))
token := mt.Next()
time.Sleep(1 * time.Second)
fmt.Println("Is MT19337 token: ", isMT19337Token(token))
}
}
func encryptOracle(src []byte) []byte {
key := util.RandAes128()
block, _ := aes.NewCipher(key)
out := make([]byte, len(src))
copy(out, src)
// random prepend and append
prefixSize := util.RandByte()%10 + 5
postfixSize := util.RandByte()%10 + 5
postfix := util.RandBytes(int(postfixSize))
out = append(util.RandBytes(int(prefixSize)), out...)
out = append(out, postfix...)
// padding
out = util.PadTo(out, 16)
// fmt.Println("before enc", out)
// random encryption mode
mode := util.RandByte()
if mode%2 == 0 {
// ecb
fmt.Println("ecb")
util.ECBEncrypt(block, out, out)
} else {
// cbc
fmt.Println("cbc")
iv := util.RandAes128()
util.CBCEncrypt(block, iv, out, out)
}
return out
}
func getMsg() (ct, iv []byte) {
ct, err := base64.StdEncoding.DecodeString(msgs[util.RandByte()%10])
if err != nil {
log.Fatal("Cannot decode", err)
}
iv = util.RandAes128()
block, _ := aes.NewCipher(key)
ct = util.PadTo(ct, block.BlockSize())
util.CBCEncrypt(block, iv, ct, ct)
return ct, iv
}
Think "STIMULUS" and "RESPONSE".
*/
import (
"bytes"
"crypto/aes"
"cryptopals/util"
"fmt"
)
type oracleFunc func(src []byte) []byte
var (
key = util.RandAes128()
prefixLen = int(util.RandByte())%32 + 1
prefix = util.RandBytes(prefixLen)
)
func encryptOracle(src []byte) []byte {
block, _ := aes.NewCipher(key)
out := make([]byte, len(src))
copy(out, src)
target := []byte("secret bytes. nobody is gonna read them.")
out = append(prefix, out...)
out = append(out, target...)
out = util.PadTo(out, 16)
// fmt.Println("before enc", out)
util.ECBEncrypt(block, out, out)