Files
crypto/pkcs12/crypto_test.go
mohammadmseet-hue d37c95e27d pkcs12: limit PBKDF iteration count to prevent CPU exhaustion
The PKCS#12 PBKDF iteration count is read directly from
the input file with no upper bound. A crafted 83-byte .p12
file can set iterations to 2^31-1 (2147483647), causing
Decode() to block a CPU core permanently.

This change adds a maximum iteration limit of 1000000 in
both verifyMac and pbDecrypterFor. Any file that specifies
more iterations than this cap is rejected with an error.

For reference, OpenSSL caps PBKDF2 at 10000000 iterations,
and scrypt is bounded by its memory-hardness parameters.
The 1000000 limit is generous for legitimate PKCS#12 files
while still preventing denial of service.

Fixes golang/go#78524

Change-Id: I1d12d6f5d90e347ca0dc113678abc51b0cff8d85
GitHub-Last-Rev: a0370d492dd4735cc7c1bb082b359ad79863fdae
GitHub-Pull-Request: golang/crypto#343
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/759900
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2026-06-04 06:58:05 -07:00

166 lines
4.1 KiB
Go

// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package pkcs12
import (
"bytes"
"crypto/x509/pkix"
"encoding/asn1"
"testing"
)
var sha1WithTripleDES = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 12, 1, 3})
func TestPbDecrypterForIterationLimit(t *testing.T) {
pass, _ := bmpString("Sesame open")
tests := []struct {
name string
iterations int
wantErr bool
}{
{"at limit", maxIterations, false},
{"over limit", maxIterations + 1, true},
{"negative", -1, true},
{"max int", 1<<31 - 1, true},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
params, _ := asn1.Marshal(pbeParams{
Salt: []byte{1, 2, 3, 4, 5, 6, 7, 8},
Iterations: tt.iterations,
})
alg := pkix.AlgorithmIdentifier{
Algorithm: sha1WithTripleDES,
Parameters: asn1.RawValue{
FullBytes: params,
},
}
_, _, err := pbDecrypterFor(alg, pass)
if tt.wantErr {
if _, ok := err.(NotImplementedError); !ok {
t.Errorf("iterations=%d: got %v, want NotImplementedError", tt.iterations, err)
}
} else {
if err != nil {
t.Errorf("iterations=%d: unexpected error: %v", tt.iterations, err)
}
}
})
}
}
func TestPbDecrypterFor(t *testing.T) {
params, _ := asn1.Marshal(pbeParams{
Salt: []byte{1, 2, 3, 4, 5, 6, 7, 8},
Iterations: 2048,
})
alg := pkix.AlgorithmIdentifier{
Algorithm: asn1.ObjectIdentifier([]int{1, 2, 3}),
Parameters: asn1.RawValue{
FullBytes: params,
},
}
pass, _ := bmpString("Sesame open")
_, _, err := pbDecrypterFor(alg, pass)
if _, ok := err.(NotImplementedError); !ok {
t.Errorf("expected not implemented error, got: %T %s", err, err)
}
alg.Algorithm = sha1WithTripleDES
cbc, blockSize, err := pbDecrypterFor(alg, pass)
if err != nil {
t.Errorf("unexpected error from pbDecrypterFor %v", err)
}
if blockSize != 8 {
t.Errorf("unexpected block size %d, wanted 8", blockSize)
}
plaintext := []byte{1, 2, 3, 4, 5, 6, 7, 8}
expectedCiphertext := []byte{185, 73, 135, 249, 137, 1, 122, 247}
ciphertext := make([]byte, len(plaintext))
cbc.CryptBlocks(ciphertext, plaintext)
if bytes.Compare(ciphertext, expectedCiphertext) != 0 {
t.Errorf("bad ciphertext, got %x but wanted %x", ciphertext, expectedCiphertext)
}
}
var pbDecryptTests = []struct {
in []byte
expected []byte
expectedError error
}{
{
[]byte("\x33\x73\xf3\x9f\xda\x49\xae\xfc\xa0\x9a\xdf\x5a\x58\xa0\xea\x46"), // 7 padding bytes
[]byte("A secret!"),
nil,
},
{
[]byte("\x33\x73\xf3\x9f\xda\x49\xae\xfc\x96\x24\x2f\x71\x7e\x32\x3f\xe7"), // 8 padding bytes
[]byte("A secret"),
nil,
},
{
[]byte("\x35\x0c\xc0\x8d\xab\xa9\x5d\x30\x7f\x9a\xec\x6a\xd8\x9b\x9c\xd9"), // 9 padding bytes, incorrect
nil,
ErrDecryption,
},
{
[]byte("\xb2\xf9\x6e\x06\x60\xae\x20\xcf\x08\xa0\x7b\xd9\x6b\x20\xef\x41"), // incorrect padding bytes: [ ... 0x04 0x02 ]
nil,
ErrDecryption,
},
}
func TestPbDecrypt(t *testing.T) {
for i, test := range pbDecryptTests {
decryptable := testDecryptable{
data: test.in,
algorithm: pkix.AlgorithmIdentifier{
Algorithm: sha1WithTripleDES,
Parameters: pbeParams{
Salt: []byte("\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8"),
Iterations: 4096,
}.RawASN1(),
},
}
password, _ := bmpString("sesame")
plaintext, err := pbDecrypt(decryptable, password)
if err != test.expectedError {
t.Errorf("#%d: got error %q, but wanted %q", i, err, test.expectedError)
continue
}
if !bytes.Equal(plaintext, test.expected) {
t.Errorf("#%d: got %x, but wanted %x", i, plaintext, test.expected)
}
}
}
type testDecryptable struct {
data []byte
algorithm pkix.AlgorithmIdentifier
}
func (d testDecryptable) Algorithm() pkix.AlgorithmIdentifier { return d.algorithm }
func (d testDecryptable) Data() []byte { return d.data }
func (params pbeParams) RawASN1() (raw asn1.RawValue) {
asn1Bytes, err := asn1.Marshal(params)
if err != nil {
panic(err)
}
_, err = asn1.Unmarshal(asn1Bytes, &raw)
if err != nil {
panic(err)
}
return
}