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 qtls
import (
"crypto/tls"
"fmt"
"unsafe"
)
//go:linkname cipherSuitesTLS13 crypto/tls.cipherSuitesTLS13
var cipherSuitesTLS13 []unsafe.Pointer
//go:linkname defaultCipherSuitesTLS13 crypto/tls.defaultCipherSuitesTLS13
var defaultCipherSuitesTLS13 []uint16
//go:linkname defaultCipherSuitesTLS13NoAES crypto/tls.defaultCipherSuitesTLS13NoAES
var defaultCipherSuitesTLS13NoAES []uint16
var cipherSuitesModified bool
// SetCipherSuite modifies the cipherSuiteTLS13 slice of cipher suites inside qtls
// such that it only contains the cipher suite with the chosen id.
// The reset function returned resets them back to the original value.
func SetCipherSuite(id uint16) (reset func()) {
if cipherSuitesModified {
panic("cipher suites modified multiple times without resetting")
}
cipherSuitesModified = true
origCipherSuitesTLS13 := append([]unsafe.Pointer{}, cipherSuitesTLS13...)
origDefaultCipherSuitesTLS13 := append([]uint16{}, defaultCipherSuitesTLS13...)
origDefaultCipherSuitesTLS13NoAES := append([]uint16{}, defaultCipherSuitesTLS13NoAES...)
// The order is given by the order of the slice elements in cipherSuitesTLS13 in qtls.
switch id {
case tls.TLS_AES_128_GCM_SHA256:
cipherSuitesTLS13 = cipherSuitesTLS13[:1]
case tls.TLS_CHACHA20_POLY1305_SHA256:
cipherSuitesTLS13 = cipherSuitesTLS13[1:2]
case tls.TLS_AES_256_GCM_SHA384:
cipherSuitesTLS13 = cipherSuitesTLS13[2:]
default:
panic(fmt.Sprintf("unexpected cipher suite: %d", id))
}
defaultCipherSuitesTLS13 = []uint16{id}
defaultCipherSuitesTLS13NoAES = []uint16{id}
return func() {
cipherSuitesTLS13 = origCipherSuitesTLS13
defaultCipherSuitesTLS13 = origDefaultCipherSuitesTLS13
defaultCipherSuitesTLS13NoAES = origDefaultCipherSuitesTLS13NoAES
cipherSuitesModified = false
}
}
|
