blob: be777fc3cfe9650930cbd75fba3870b0833cd729 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
package cryptfs
import (
"bytes"
"crypto/rand"
"encoding/binary"
"encoding/hex"
"fmt"
)
// Get "n" random bytes from /dev/urandom or panic
func RandBytes(n int) []byte {
b := make([]byte, n)
_, err := rand.Read(b)
if err != nil {
panic("Failed to read random bytes: " + err.Error())
}
return b
}
// Return a secure random uint64
func RandUint64() uint64 {
b := RandBytes(8)
return binary.BigEndian.Uint64(b)
}
type nonceGenerator struct {
lastNonce []byte
nonceLen int // bytes
}
// Get a random 96 bit nonce
func (n *nonceGenerator) Get() []byte {
nonce := RandBytes(n.nonceLen)
Debug.Printf("nonceGenerator.Get(): %s\n", hex.EncodeToString(nonce))
if bytes.Equal(nonce, n.lastNonce) {
m := fmt.Sprintf("Got the same nonce twice: %s. This should never happen!", hex.EncodeToString(nonce))
panic(m)
}
n.lastNonce = nonce
return nonce
}
|
