use pbkdf2 from OpenSSL if FIPS mode is enabled

This patch modifies the x/crypto/pbkdf2 function to use OpenSSL

if FIPS mode is enabled.

diff --git a/vendor/golang.org/x/crypto/internal/boring/boring.go b/vendor/golang.org/x/crypto/internal/boring/boring.go

new file mode 100644

index 0000000000..5a06918832

--- /dev/null

+++ b/vendor/golang.org/x/crypto/internal/boring/boring.go

@@ -0,0 +1,74 @@

+// Copyright 2017 The Go Authors. All rights reserved.

+// Copyright 2021 Red Hat.

+// Use of this source code is governed by a BSD-style

+// license that can be found in the LICENSE file.

+

+// +build linux

+// +build !android

+// +build !no_openssl

+// +build !cmd_go_bootstrap

+// +build !msan

+

+package boring

+

+// #include "openssl_pbkdf2.h"

+// #cgo LDFLAGS: -ldl

+import "C"

+import (

+	"bytes"

+	"crypto/sha1"

+	"crypto/sha256"

+	"hash"

+	"unsafe"

+)

+

+var (

+	emptySha1   = sha1.Sum([]byte{})

+	emptySha256 = sha256.Sum256([]byte{})

+)

+

+func hashToMD(h hash.Hash) *C.GO_EVP_MD {

+	emptyHash := h.Sum([]byte{})

+

+	switch {

+	case bytes.Equal(emptyHash, emptySha1[:]):

+		return C._goboringcrypto_EVP_sha1()

+	case bytes.Equal(emptyHash, emptySha256[:]):

+		return C._goboringcrypto_EVP_sha256()

+	}

+	return nil

+}

+

+// charptr returns the address of the underlying array in b,

+// being careful not to panic when b has zero length.

+func charptr(b []byte) *C.char {

+	if len(b) == 0 {

+		return nil

+	}

+	return (*C.char)(unsafe.Pointer(&b[0]))

+}

+

+// ucharptr returns the address of the underlying array in b,

+// being careful not to panic when b has zero length.

+func ucharptr(b []byte) *C.uchar {

+	if len(b) == 0 {

+		return nil

+	}

+	return (*C.uchar)(unsafe.Pointer(&b[0]))

+}

+

+func Pbkdf2Key(password, salt []byte, iter, keyLen int, h func() hash.Hash) []byte {

+	// println("[debug] using pbkdf2 from OpenSSL")

+	ch := h()

+	md := hashToMD(ch)

+	if md == nil {

+		return nil

+	}

+

+	out := make([]byte, keyLen)

+	ok := C._goboringcrypto_PKCS5_PBKDF2_HMAC(charptr(password), C.int(len(password)), ucharptr(salt), C.int(len(salt)), C.int(iter), md, C.int(keyLen), ucharptr(out))

+	if ok != 1 {

+		panic("boringcrypto: PKCS5_PBKDF2_HMAC failed")

+	}

+	return out

+}

diff --git a/vendor/golang.org/x/crypto/internal/boring/notboring.go b/vendor/golang.org/x/crypto/internal/boring/notboring.go

new file mode 100644

index 0000000000..e244fb5663

--- /dev/null

+++ b/vendor/golang.org/x/crypto/internal/boring/notboring.go

@@ -0,0 +1,16 @@

+// Copyright 2017 The Go Authors. All rights reserved.

+// Copyright 2021 Red Hat.

+// Use of this source code is governed by a BSD-style

+// license that can be found in the LICENSE file.

+

+// +build !linux !cgo android cmd_go_bootstrap msan no_openssl

+

+package boring

+

+import (

+	"hash"

+)

+

+func Pbkdf2Key(password, salt []byte, iter, keyLen int, h func() hash.Hash) []byte {

+	panic("boringcrypto: not available")

+}

diff --git a/vendor/golang.org/x/crypto/internal/boring/openssl_pbkdf2.h b/vendor/golang.org/x/crypto/internal/boring/openssl_pbkdf2.h

new file mode 100644

index 0000000000..6dfdf10424

--- /dev/null

+++ b/vendor/golang.org/x/crypto/internal/boring/openssl_pbkdf2.h

@@ -0,0 +1,5 @@

+#include "/usr/lib/golang/src/vendor/github.com/golang-fips/openssl-fips/openssl/goopenssl.h"

+

+DEFINEFUNC(int, PKCS5_PBKDF2_HMAC,

+    (const char *pass, int passlen, const unsigned char *salt, int saltlen, int iter, EVP_MD *digest, int keylen, unsigned char *out),

+    (pass, passlen, salt, saltlen, iter, digest, keylen, out))

diff --git a/vendor/golang.org/x/crypto/pbkdf2/pbkdf2.go b/vendor/golang.org/x/crypto/pbkdf2/pbkdf2.go

index 593f653008..799a611f94 100644

--- a/vendor/golang.org/x/crypto/pbkdf2/pbkdf2.go

+++ b/vendor/golang.org/x/crypto/pbkdf2/pbkdf2.go

@@ -19,8 +19,11 @@ pbkdf2.Key.

 package pbkdf2 // import "golang.org/x/crypto/pbkdf2"

 import (

+	"crypto/boring"

 	"crypto/hmac"

 	"hash"

+

+	xboring "golang.org/x/crypto/internal/boring"

 )

 // Key derives a key from the password, salt and iteration count, returning a

@@ -40,6 +43,10 @@ import (

 // Using a higher iteration count will increase the cost of an exhaustive

 // search but will also make derivation proportionally slower.

 func Key(password, salt []byte, iter, keyLen int, h func() hash.Hash) []byte {

+	if boring.Enabled() {

+		return xboring.Pbkdf2Key(password, salt, iter, keyLen, h)

+	}

+

 	prf := hmac.New(h, password)

 	hashLen := prf.Size()

 	numBlocks := (keyLen + hashLen - 1) / hashLen