crypto/internal/fips/aes: add CAST

For #69536

Change-Id: I6ecbe8b05f9f01afe2aa32c59fc56c9e1c6ea6b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/626437
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/crypto/internal/fips/aes/cast.go b/src/crypto/internal/fips/aes/cast.go
new file mode 100644 (file)
index 0000000..e1aea8a
--- /dev/null
+++ b/src/crypto/internal/fips/aes/cast.go
@@ -0,0 +1,46 @@
+// Copyright 2024 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 aes
+
+import (
+       "bytes"
+       "crypto/internal/fips"
+       "errors"
+)
+
+func init() {
+       fips.CAST("AES-CBC", func() error {
+               key := []byte{
+                       0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+                       0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
+               }
+               iv := [16]byte{
+                       0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
+                       0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
+               }
+               plaintext := []byte{
+                       0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
+                       0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
+               }
+               ciphertext := []byte{
+                       0xdf, 0x76, 0x26, 0x4b, 0xd3, 0xb2, 0xc4, 0x8d,
+                       0x40, 0xa2, 0x6e, 0x7a, 0xc4, 0xff, 0xbd, 0x35,
+               }
+               b, err := New(key)
+               if err != nil {
+                       return err
+               }
+               buf := make([]byte, 16)
+               NewCBCEncrypter(b, iv).CryptBlocks(buf, plaintext)
+               if !bytes.Equal(buf, ciphertext) {
+                       return errors.New("unexpected result")
+               }
+               NewCBCDecrypter(b, iv).CryptBlocks(buf, ciphertext)
+               if !bytes.Equal(buf, plaintext) {
+                       return errors.New("unexpected result")
+               }
+               return nil
+       })
+}

diff --git a/src/crypto/internal/fips/aes/gcm/cast.go b/src/crypto/internal/fips/aes/gcm/cast.go
new file mode 100644 (file)
index 0000000..3a2b6b7
--- /dev/null
+++ b/src/crypto/internal/fips/aes/gcm/cast.go
@@ -0,0 +1,42 @@
+// Copyright 2024 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 gcm
+
+import (
+       "crypto/internal/fips"
+       "crypto/internal/fips/aes"
+       "errors"
+)
+
+func init() {
+       // Counter KDF covers CMAC per IG 10.3.B, and CMAC covers GCM per IG 10.3.A
+       // Resolution 1.d(i). AES decryption is covered by the CBC CAST in package
+       // crypto/internal/fips/aes.
+       fips.CAST("CounterKDF", func() error {
+               key := []byte{
+                       0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+                       0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
+               }
+               context := [12]byte{
+                       0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
+                       0x29, 0x2a, 0x2b, 0x2c,
+               }
+               want := [32]byte{
+                       0xe6, 0x86, 0x96, 0x97, 0x08, 0xfc, 0x90, 0x30,
+                       0x36, 0x1c, 0x65, 0x94, 0xb2, 0x62, 0xa5, 0xf7,
+                       0xcb, 0x9d, 0x93, 0x94, 0xda, 0xf1, 0x94, 0x09,
+                       0x6a, 0x27, 0x5e, 0x85, 0x22, 0x5e, 0x7a, 0xee,
+               }
+               b, err := aes.New(key)
+               if err != nil {
+                       return err
+               }
+               got := NewCounterKDF(b).DeriveKey(0xFF, context)
+               if got != want {
+                       return errors.New("unexpected result")
+               }
+               return nil
+       })
+}

diff --git a/src/crypto/internal/fips/cast_external_test.go b/src/crypto/internal/fips/cast_external_test.go
index d31086d5e336adb8d5b5728ea485ec3eb673cbe5..2698f9a9d88a8601ed278bfcd5ef82a20aa53315 100644 (file)
--- a/src/crypto/internal/fips/cast_external_test.go
+++ b/src/crypto/internal/fips/cast_external_test.go
@@ -12,6 +12,8 @@ import (
        "testing"
 
        // Import packages that define CASTs to test them.
+       _ "crypto/internal/fips/aes"
+       _ "crypto/internal/fips/aes/gcm"
        _ "crypto/internal/fips/drbg"
        _ "crypto/internal/fips/hkdf"
        _ "crypto/internal/fips/hmac"