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
43
44
45
46
47
48
49
50
51
52
|
// Package rocacheck checks if a key was generated by broken Infineon code and
// is vulnerable to factorization via the Return of Coppersmith's Attack (ROCA)
// / CVE-2017-15361.
package rocacheck
import (
"crypto/rsa"
"math/big"
)
type test struct {
Prime *big.Int
Fingerprints map[int64]struct{}
}
var tests = make([]test, 17)
func init() {
bigOne := big.NewInt(1)
n := &big.Int{}
// relations table from https://github.com/crocs-muni/roca/pull/40
for i, r := range [][2]int64{
{2, 11}, {6, 13}, {8, 17}, {9, 19}, {3, 37}, {26, 53}, {20, 61},
{35, 71}, {24, 73}, {13, 79}, {6, 97}, {51, 103}, {53, 107},
{54, 109}, {42, 127}, {50, 151}, {78, 157},
} {
fps := make(map[int64]struct{})
bp := big.NewInt(r[1])
br := big.NewInt(r[0])
for j := int64(0); j < r[1]; j++ {
if n.Exp(big.NewInt(j), br, bp).Cmp(bigOne) == 0 {
fps[j] = struct{}{}
}
}
tests[i] = test{
Prime: big.NewInt(r[1]),
Fingerprints: fps,
}
}
}
// IsWeak returns true if a RSA public key is vulnerable to Return of
// Coppersmith's Attack (ROCA).
func IsWeak(k *rsa.PublicKey) bool {
tmp := &big.Int{}
for _, t := range tests {
if _, ok := t.Fingerprints[tmp.Mod(k.N, t.Prime).Int64()]; !ok {
return false
}
}
return true
}
|
