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update DES and 3DES to use ECB instead of CBC by default
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qmuntal committed Sep 25, 2024
1 parent 42b239c commit 5918ccd
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Showing 5 changed files with 294 additions and 2 deletions.
4 changes: 2 additions & 2 deletions cng/des.go
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@ type desCipher struct {
}

func NewDESCipher(key []byte) (cipher.Block, error) {
kh, err := newCipherHandle(bcrypt.DES_ALGORITHM, "", key)
kh, err := newCipherHandle(bcrypt.DES_ALGORITHM, bcrypt.CHAIN_MODE_ECB, key)
if err != nil {
return nil, err
}
Expand All @@ -34,7 +34,7 @@ func NewDESCipher(key []byte) (cipher.Block, error) {
}

func NewTripleDESCipher(key []byte) (cipher.Block, error) {
kh, err := newCipherHandle(bcrypt.DES3_ALGORITHM, "", key)
kh, err := newCipherHandle(bcrypt.DES3_ALGORITHM, bcrypt.CHAIN_MODE_ECB, key)
if err != nil {
return nil, err
}
Expand Down
12 changes: 12 additions & 0 deletions cng/des_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ import (
"testing"

"github.com/microsoft/go-crypto-winnative/cng"
"github.com/microsoft/go-crypto-winnative/internal/cryptotest"
)

type CryptTest struct {
Expand Down Expand Up @@ -1669,6 +1670,17 @@ func TestTripleDESCBCDecryptSimple(t *testing.T) {
}
}

// Test DES against the general cipher.Block interface tester.
func TestDESBlock(t *testing.T) {
t.Run("DES", func(t *testing.T) {
cryptotest.TestBlock(t, 8, cng.NewDESCipher)
})

t.Run("TripleDES", func(t *testing.T) {
cryptotest.TestBlock(t, 24, cng.NewTripleDESCipher)
})
}

func BenchmarkEncrypt(b *testing.B) {
tt := encryptDESTests[0]
c, err := cng.NewDESCipher(tt.key)
Expand Down
6 changes: 6 additions & 0 deletions internal/cryptotest/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,6 @@
The `internal/cryptotest` package provides a set of tests for cryptographic primitives.

`internal/cryptotest` has been copied from the Go standard library's [crypo/internal/cryptotest](https://github.com/golang/go/tree/807e01db4840e25e4d98911b28a8fa54244b8dfa/src/crypto/internal/cryptotest)
package and trimmed down to only include the tests that are relevant for the `openssl` package.

[1]: https://github.com/golang/go/tree/807e01db4840e25e4d98911b28a8fa54244b8dfa/src/crypto/internal/cryptotest
256 changes: 256 additions & 0 deletions internal/cryptotest/block.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,256 @@
// 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 cryptotest

import (
"bytes"
"crypto/cipher"
"testing"
)

// This file is a copy of https://github.com/golang/go/blob/9e9b1f57c26a6d13fdaebef67136718b8042cdba/src/crypto/internal/cryptotest/block.go.

type MakeBlock func(key []byte) (cipher.Block, error)

// TestBlock performs a set of tests on cipher.Block implementations, checking
// the documented requirements of BlockSize, Encrypt, and Decrypt.
func TestBlock(t *testing.T, keySize int, mb MakeBlock) {
// Generate random key
key := make([]byte, keySize)
newRandReader(t).Read(key)
t.Logf("Cipher key: 0x%x", key)

block, err := mb(key)
if err != nil {
t.Fatal(err)
}

blockSize := block.BlockSize()

t.Run("Encryption", func(t *testing.T) {
testCipher(t, block.Encrypt, blockSize)
})

t.Run("Decryption", func(t *testing.T) {
testCipher(t, block.Decrypt, blockSize)
})

// Checks baseline Encrypt/Decrypt functionality. More thorough
// implementation-specific characterization/golden tests should be done
// for each block cipher implementation.
t.Run("Roundtrip", func(t *testing.T) {
rng := newRandReader(t)

// Check Decrypt inverts Encrypt
before, ciphertext, after := make([]byte, blockSize), make([]byte, blockSize), make([]byte, blockSize)

rng.Read(before)

block.Encrypt(ciphertext, before)
block.Decrypt(after, ciphertext)

if !bytes.Equal(after, before) {
t.Errorf("plaintext is different after an encrypt/decrypt cycle; got %x, want %x", after, before)
}

// Check Encrypt inverts Decrypt (assumes block ciphers are deterministic)
before, plaintext, after := make([]byte, blockSize), make([]byte, blockSize), make([]byte, blockSize)

rng.Read(before)

block.Decrypt(plaintext, before)
block.Encrypt(after, plaintext)

if !bytes.Equal(after, before) {
t.Errorf("ciphertext is different after a decrypt/encrypt cycle; got %x, want %x", after, before)
}
})

}

func testCipher(t *testing.T, cipher func(dst, src []byte), blockSize int) {
t.Run("AlterInput", func(t *testing.T) {
rng := newRandReader(t)

// Make long src that shouldn't be modified at all, within block
// size scope or beyond it
src, before := make([]byte, blockSize*2), make([]byte, blockSize*2)
rng.Read(src)
copy(before, src)

dst := make([]byte, blockSize)

cipher(dst, src)
if !bytes.Equal(src, before) {
t.Errorf("block cipher modified src; got %x, want %x", src, before)
}
})

t.Run("Aliasing", func(t *testing.T) {
rng := newRandReader(t)

buff, expectedOutput := make([]byte, blockSize), make([]byte, blockSize)

// Record what output is when src and dst are different
rng.Read(buff)
cipher(expectedOutput, buff)

// Check that the same output is generated when src=dst alias to the same
// memory
cipher(buff, buff)
if !bytes.Equal(buff, expectedOutput) {
t.Errorf("block cipher produced different output when dst = src; got %x, want %x", buff, expectedOutput)
}
})

t.Run("OutOfBoundsWrite", func(t *testing.T) {
rng := newRandReader(t)

src := make([]byte, blockSize)
rng.Read(src)

// Make a buffer with dst in the middle and data on either end
buff := make([]byte, blockSize*3)
endOfPrefix, startOfSuffix := blockSize, blockSize*2
rng.Read(buff[:endOfPrefix])
rng.Read(buff[startOfSuffix:])
dst := buff[endOfPrefix:startOfSuffix]

// Record the prefix and suffix data to make sure they aren't written to
initPrefix, initSuffix := make([]byte, blockSize), make([]byte, blockSize)
copy(initPrefix, buff[:endOfPrefix])
copy(initSuffix, buff[startOfSuffix:])

// Write to dst (the middle of the buffer) and make sure it doesn't write
// beyond the dst slice
cipher(dst, src)
if !bytes.Equal(buff[startOfSuffix:], initSuffix) {
t.Errorf("block cipher did out of bounds write after end of dst slice; got %x, want %x", buff[startOfSuffix:], initSuffix)
}
if !bytes.Equal(buff[:endOfPrefix], initPrefix) {
t.Errorf("block cipher did out of bounds write before beginning of dst slice; got %x, want %x", buff[:endOfPrefix], initPrefix)
}

// Check that dst isn't written to beyond BlockSize even if there is room
// in the slice
dst = buff[endOfPrefix:] // Extend dst to include suffix
cipher(dst, src)
if !bytes.Equal(buff[startOfSuffix:], initSuffix) {
t.Errorf("block cipher modified dst past BlockSize bytes; got %x, want %x", buff[startOfSuffix:], initSuffix)
}
})

// Check that output of cipher isn't affected by adjacent data beyond input
// slice scope
// For encryption, this assumes block ciphers encrypt deterministically
t.Run("OutOfBoundsRead", func(t *testing.T) {
rng := newRandReader(t)

src := make([]byte, blockSize)
rng.Read(src)
expectedDst := make([]byte, blockSize)
cipher(expectedDst, src)

// Make a buffer with src in the middle and data on either end
buff := make([]byte, blockSize*3)
endOfPrefix, startOfSuffix := blockSize, blockSize*2

copy(buff[endOfPrefix:startOfSuffix], src)
rng.Read(buff[:endOfPrefix])
rng.Read(buff[startOfSuffix:])

testDst := make([]byte, blockSize)
cipher(testDst, buff[endOfPrefix:startOfSuffix])
if !bytes.Equal(testDst, expectedDst) {
t.Errorf("block cipher affected by data outside of src slice bounds; got %x, want %x", testDst, expectedDst)
}

// Check that src isn't read from beyond BlockSize even if the slice is
// longer and contains data in the suffix
cipher(testDst, buff[endOfPrefix:]) // Input long src
if !bytes.Equal(testDst, expectedDst) {
t.Errorf("block cipher affected by src data beyond BlockSize bytes; got %x, want %x", buff[startOfSuffix:], expectedDst)
}
})

t.Run("NonZeroDst", func(t *testing.T) {
rng := newRandReader(t)

// Record what the cipher writes into a destination of zeroes
src := make([]byte, blockSize)
rng.Read(src)
expectedDst := make([]byte, blockSize)

cipher(expectedDst, src)

// Make nonzero dst
dst := make([]byte, blockSize*2)
rng.Read(dst)

// Remember the random suffix which shouldn't be written to
expectedDst = append(expectedDst, dst[blockSize:]...)

cipher(dst, src)
if !bytes.Equal(dst, expectedDst) {
t.Errorf("block cipher behavior differs when given non-zero dst; got %x, want %x", dst, expectedDst)
}
})

t.Run("BufferOverlap", func(t *testing.T) {
rng := newRandReader(t)

buff := make([]byte, blockSize*2)
rng.Read((buff))

// Make src and dst slices point to same array with inexact overlap
src := buff[:blockSize]
dst := buff[1 : blockSize+1]
mustPanic(t, "invalid buffer overlap", func() { cipher(dst, src) })

// Only overlap on one byte
src = buff[:blockSize]
dst = buff[blockSize-1 : 2*blockSize-1]
mustPanic(t, "invalid buffer overlap", func() { cipher(dst, src) })

// src comes after dst with one byte overlap
src = buff[blockSize-1 : 2*blockSize-1]
dst = buff[:blockSize]
mustPanic(t, "invalid buffer overlap", func() { cipher(dst, src) })
})

// Test short input/output.
// Assembly used to not notice.
// See issue 7928.
t.Run("ShortBlock", func(t *testing.T) {
// Returns slice of n bytes of an n+1 length array. Lets us test that a
// slice is still considered too short even if the underlying array it
// points to is large enough
byteSlice := func(n int) []byte { return make([]byte, n+1)[0:n] }

// Off by one byte
mustPanic(t, "input not full block", func() { cipher(byteSlice(blockSize), byteSlice(blockSize-1)) })
mustPanic(t, "output not full block", func() { cipher(byteSlice(blockSize-1), byteSlice(blockSize)) })

// Small slices
mustPanic(t, "input not full block", func() { cipher(byteSlice(1), byteSlice(1)) })
mustPanic(t, "input not full block", func() { cipher(byteSlice(100), byteSlice(1)) })
mustPanic(t, "output not full block", func() { cipher(byteSlice(1), byteSlice(100)) })
})
}

func mustPanic(t *testing.T, msg string, f func()) {
t.Helper()

defer func() {
t.Helper()

err := recover()

if err == nil {
t.Errorf("function did not panic for %q", msg)
}
}()
f()
}
18 changes: 18 additions & 0 deletions internal/cryptotest/hash.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
// 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 cryptotest

import (
"io"
"math/rand"
"testing"
"time"
)

func newRandReader(t *testing.T) io.Reader {
seed := time.Now().UnixNano()
t.Logf("Deterministic RNG seed: 0x%x", seed)
return rand.New(rand.NewSource(seed))
}

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