func IdForKey(pk rsa.PublicKey) Id {
// Write the Rsa64 representation of public key into Sha256
pk64 := []byte(rsa64.PubToBase64(&pk))
sha256 := sha256.New()
for {
n, err := sha256.Write(pk64)
if err != nil {
panic("sha256 malfunction")
}
if n == len(pk64) {
break
}
pk64 = pk64[n:]
}
// Compute and fold the Sha256 hash
h := sha256.Sum()
if len(h) != 32 {
panic("expecting 32 bytes")
}
for i := 1; i < 4; i++ {
for j := 0; j < 8; j++ {
h[j] ^= h[8*i+j]
}
}
id64, err := bytes.BytesToInt64(h[0:8])
if err != nil {
panic("logic")
}
return Id(id64)
}
func (id Id) Mask() Id {
sha := sha1.New()
b := bytes.Int64ToBytes(int64(uint64(id)))
sha.Write(b)
sum := sha.Sum()
i, err := bytes.BytesToInt64(sum[0 : 64/8])
if err != nil {
panic("id, mask")
}
return Id(uint64(i))
}