mirror of
https://github.com/cunnie/sslip.io.git
synced 2025-10-05 15:46:50 +08:00
b1b95e8214
I have a test helper which produces a random 8-character string consisting of mixed-case alphabetic characters; however, there's a small chance (6/26^8 == 0.0008%) that it would produce a valid 8-character hexadecimal string, which could be mistakenly recognized as an IP address, which _might_ break a test. Out of an abundance of caution, I guard against producing an 8-byte string that might be accidentally recognized as 8-byte hexadecimal notation by making sure the first & last bytes are NOT hex characters.
43 lines
1.4 KiB
Go
43 lines
1.4 KiB
Go
package testhelper
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"math/rand"
|
|
"net"
|
|
)
|
|
|
|
// RandomIPv6Address is used for fuzz testing
|
|
func RandomIPv6Address() net.IP {
|
|
upperHalf := make([]byte, 8)
|
|
lowerHalf := make([]byte, 8)
|
|
binary.LittleEndian.PutUint64(upperHalf, rand.Uint64())
|
|
binary.LittleEndian.PutUint64(lowerHalf, rand.Uint64())
|
|
ipv6 := net.IP(append(upperHalf, lowerHalf...))
|
|
// IPv6 addrs have a lot of all-zero two-byte sections
|
|
// So we zero-out ~50% of the sections
|
|
for i := 0; i < 8; i++ {
|
|
if rand.Int()%2 == 0 {
|
|
for j := 0; j < 2; j++ {
|
|
ipv6[i*2+j] = 0
|
|
}
|
|
}
|
|
}
|
|
// avoid pathological case: an IPv4 address []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, ?, ?, ?, ?})
|
|
ipv6[10] &= 0xfe
|
|
return ipv6
|
|
}
|
|
|
|
// Random8ByteString() returns an 8-char mixed-case string consisting solely of the letters a-z.
|
|
// the first & last characters are non-hexadecimal to avoid confusion with hexadecimal notation
|
|
func Random8ByteString() string {
|
|
var randomString []byte
|
|
// 71 == ascii 'G', +32 (103) == ascii 'g'
|
|
randomString = append(randomString, byte(71+32*rand.Intn(2)+rand.Intn(20)))
|
|
for range 6 {
|
|
// 65 == ascii 'A', +32 (96) == ascii 'a', there are 26 letters in the alphabet. Mix upper case, too.
|
|
randomString = append(randomString, byte(65+32*rand.Intn(2)+rand.Intn(26)))
|
|
}
|
|
randomString = append(randomString, byte(71+32*rand.Intn(2)+rand.Intn(20)))
|
|
return string(randomString)
|
|
}
|