crypto/internal/fips/hkdf: new package

Tests imported from x/crypto, but the actual implementation was simpler
to implement ex-novo with a #61477-like API.

Updates #61477
For #69536

Change-Id: I5a9e8a71d8abd5b2aa6b74e73bf7f631ed0115cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/621275
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>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/src/crypto/internal/fips/cast_external_test.go b/src/crypto/internal/fips/cast_external_test.go
index e836a852db086bfda06403c16523cf07d25614d3..60859a50d928f15d956a697f81b8bd7abc225869 100644 (file)
--- a/src/crypto/internal/fips/cast_external_test.go
+++ b/src/crypto/internal/fips/cast_external_test.go
@@ -13,6 +13,7 @@ import (
 
        // Import packages that define CASTs to test them.
        _ "crypto/internal/fips/drbg"
+       _ "crypto/internal/fips/hkdf"
        _ "crypto/internal/fips/hmac"
        _ "crypto/internal/fips/sha256"
        _ "crypto/internal/fips/sha3"

diff --git a/src/crypto/internal/fips/hkdf/cast.go b/src/crypto/internal/fips/hkdf/cast.go
new file mode 100644 (file)
index 0000000..67871a4
--- /dev/null
+++ b/src/crypto/internal/fips/hkdf/cast.go
@@ -0,0 +1,32 @@
+// 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 hkdf
+
+import (
+       "bytes"
+       "crypto/internal/fips"
+       "crypto/internal/fips/sha256"
+       "errors"
+)
+
+func init() {
+       fips.CAST("HKDF-SHA2-256", func() error {
+               input := []byte{
+                       0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+                       0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
+               }
+               want := []byte{
+                       0xb6, 0x53, 0x00, 0x5b, 0x51, 0x6d, 0x2b, 0xc9,
+                       0x4a, 0xe4, 0xf9, 0x51, 0x73, 0x1f, 0x71, 0x21,
+                       0xa6, 0xc1, 0xde, 0x42, 0x4f, 0x2c, 0x99, 0x60,
+                       0x64, 0xdb, 0x66, 0x3e, 0xec, 0xa6, 0x37, 0xff,
+               }
+               got := Key(sha256.New, input, input, input, len(want))
+               if !bytes.Equal(got, want) {
+                       return errors.New("unexpected result")
+               }
+               return nil
+       })
+}

diff --git a/src/crypto/internal/fips/hkdf/hkdf.go b/src/crypto/internal/fips/hkdf/hkdf.go
new file mode 100644 (file)
index 0000000..914c955
--- /dev/null
+++ b/src/crypto/internal/fips/hkdf/hkdf.go
@@ -0,0 +1,53 @@
+// 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 hkdf
+
+import (
+       "crypto/internal/fips"
+       "crypto/internal/fips/hmac"
+)
+
+func Extract[H fips.Hash](h func() H, secret, salt []byte) []byte {
+       if len(secret) < 112/8 {
+               fips.RecordNonApproved()
+       }
+       if salt == nil {
+               salt = make([]byte, h().Size())
+       }
+       extractor := hmac.New(h, salt)
+       extractor.Write(secret)
+       return extractor.Sum(nil)
+}
+
+func Expand[H fips.Hash](h func() H, pseudorandomKey, info []byte, keyLen int) []byte {
+       out := make([]byte, 0, keyLen)
+       expander := hmac.New(h, pseudorandomKey)
+       var counter uint8
+       var buf []byte
+
+       for len(out) < keyLen {
+               counter++
+               if counter == 0 {
+                       panic("hkdf: counter overflow")
+               }
+               if counter > 1 {
+                       expander.Reset()
+               }
+               expander.Write(buf)
+               expander.Write(info)
+               expander.Write([]byte{counter})
+               buf = expander.Sum(buf[:0])
+               remain := keyLen - len(out)
+               remain = min(remain, len(buf))
+               out = append(out, buf[:remain]...)
+       }
+
+       return out
+}
+
+func Key[H fips.Hash](h func() H, secret, salt, info []byte, keyLen int) []byte {
+       prk := Extract(h, secret, salt)
+       return Expand(h, prk, info, keyLen)
+}

diff --git a/src/crypto/internal/fips/hkdf/hkdf_test.go b/src/crypto/internal/fips/hkdf/hkdf_test.go
new file mode 100644 (file)
index 0000000..f78d1e7
--- /dev/null
+++ b/src/crypto/internal/fips/hkdf/hkdf_test.go
@@ -0,0 +1,361 @@
+// Copyright 2014 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 hkdf_test
+
+import (
+       "bytes"
+       "crypto/internal/fips/hkdf"
+       "crypto/md5"
+       "crypto/sha1"
+       "crypto/sha256"
+       "crypto/sha512"
+       "hash"
+       "testing"
+)
+
+type hkdfTest struct {
+       hash   func() hash.Hash
+       master []byte
+       salt   []byte
+       prk    []byte
+       info   []byte
+       out    []byte
+}
+
+var hkdfTests = []hkdfTest{
+       // Tests from RFC 5869
+       {
+               sha256.New,
+               []byte{
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+               },
+               []byte{
+                       0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                       0x08, 0x09, 0x0a, 0x0b, 0x0c,
+               },
+               []byte{
+                       0x07, 0x77, 0x09, 0x36, 0x2c, 0x2e, 0x32, 0xdf,
+                       0x0d, 0xdc, 0x3f, 0x0d, 0xc4, 0x7b, 0xba, 0x63,
+                       0x90, 0xb6, 0xc7, 0x3b, 0xb5, 0x0f, 0x9c, 0x31,
+                       0x22, 0xec, 0x84, 0x4a, 0xd7, 0xc2, 0xb3, 0xe5,
+               },
+               []byte{
+                       0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+                       0xf8, 0xf9,
+               },
+               []byte{
+                       0x3c, 0xb2, 0x5f, 0x25, 0xfa, 0xac, 0xd5, 0x7a,
+                       0x90, 0x43, 0x4f, 0x64, 0xd0, 0x36, 0x2f, 0x2a,
+                       0x2d, 0x2d, 0x0a, 0x90, 0xcf, 0x1a, 0x5a, 0x4c,
+                       0x5d, 0xb0, 0x2d, 0x56, 0xec, 0xc4, 0xc5, 0xbf,
+                       0x34, 0x00, 0x72, 0x08, 0xd5, 0xb8, 0x87, 0x18,
+                       0x58, 0x65,
+               },
+       },
+       {
+               sha256.New,
+               []byte{
+                       0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                       0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+                       0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+                       0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+                       0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+                       0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+                       0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+                       0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+                       0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
+                       0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+               },
+               []byte{
+                       0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+                       0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
+                       0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+                       0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
+                       0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+                       0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+                       0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
+                       0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+                       0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+                       0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+               },
+               []byte{
+                       0x06, 0xa6, 0xb8, 0x8c, 0x58, 0x53, 0x36, 0x1a,
+                       0x06, 0x10, 0x4c, 0x9c, 0xeb, 0x35, 0xb4, 0x5c,
+                       0xef, 0x76, 0x00, 0x14, 0x90, 0x46, 0x71, 0x01,
+                       0x4a, 0x19, 0x3f, 0x40, 0xc1, 0x5f, 0xc2, 0x44,
+               },
+               []byte{
+                       0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
+                       0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
+                       0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
+                       0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
+                       0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
+                       0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
+                       0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
+                       0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
+                       0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+                       0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
+               },
+               []byte{
+                       0xb1, 0x1e, 0x39, 0x8d, 0xc8, 0x03, 0x27, 0xa1,
+                       0xc8, 0xe7, 0xf7, 0x8c, 0x59, 0x6a, 0x49, 0x34,
+                       0x4f, 0x01, 0x2e, 0xda, 0x2d, 0x4e, 0xfa, 0xd8,
+                       0xa0, 0x50, 0xcc, 0x4c, 0x19, 0xaf, 0xa9, 0x7c,
+                       0x59, 0x04, 0x5a, 0x99, 0xca, 0xc7, 0x82, 0x72,
+                       0x71, 0xcb, 0x41, 0xc6, 0x5e, 0x59, 0x0e, 0x09,
+                       0xda, 0x32, 0x75, 0x60, 0x0c, 0x2f, 0x09, 0xb8,
+                       0x36, 0x77, 0x93, 0xa9, 0xac, 0xa3, 0xdb, 0x71,
+                       0xcc, 0x30, 0xc5, 0x81, 0x79, 0xec, 0x3e, 0x87,
+                       0xc1, 0x4c, 0x01, 0xd5, 0xc1, 0xf3, 0x43, 0x4f,
+                       0x1d, 0x87,
+               },
+       },
+       {
+               sha256.New,
+               []byte{
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+               },
+               []byte{},
+               []byte{
+                       0x19, 0xef, 0x24, 0xa3, 0x2c, 0x71, 0x7b, 0x16,
+                       0x7f, 0x33, 0xa9, 0x1d, 0x6f, 0x64, 0x8b, 0xdf,
+                       0x96, 0x59, 0x67, 0x76, 0xaf, 0xdb, 0x63, 0x77,
+                       0xac, 0x43, 0x4c, 0x1c, 0x29, 0x3c, 0xcb, 0x04,
+               },
+               []byte{},
+               []byte{
+                       0x8d, 0xa4, 0xe7, 0x75, 0xa5, 0x63, 0xc1, 0x8f,
+                       0x71, 0x5f, 0x80, 0x2a, 0x06, 0x3c, 0x5a, 0x31,
+                       0xb8, 0xa1, 0x1f, 0x5c, 0x5e, 0xe1, 0x87, 0x9e,
+                       0xc3, 0x45, 0x4e, 0x5f, 0x3c, 0x73, 0x8d, 0x2d,
+                       0x9d, 0x20, 0x13, 0x95, 0xfa, 0xa4, 0xb6, 0x1a,
+                       0x96, 0xc8,
+               },
+       },
+       {
+               sha256.New,
+               []byte{
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+               },
+               nil,
+               []byte{
+                       0x19, 0xef, 0x24, 0xa3, 0x2c, 0x71, 0x7b, 0x16,
+                       0x7f, 0x33, 0xa9, 0x1d, 0x6f, 0x64, 0x8b, 0xdf,
+                       0x96, 0x59, 0x67, 0x76, 0xaf, 0xdb, 0x63, 0x77,
+                       0xac, 0x43, 0x4c, 0x1c, 0x29, 0x3c, 0xcb, 0x04,
+               },
+               nil,
+               []byte{
+                       0x8d, 0xa4, 0xe7, 0x75, 0xa5, 0x63, 0xc1, 0x8f,
+                       0x71, 0x5f, 0x80, 0x2a, 0x06, 0x3c, 0x5a, 0x31,
+                       0xb8, 0xa1, 0x1f, 0x5c, 0x5e, 0xe1, 0x87, 0x9e,
+                       0xc3, 0x45, 0x4e, 0x5f, 0x3c, 0x73, 0x8d, 0x2d,
+                       0x9d, 0x20, 0x13, 0x95, 0xfa, 0xa4, 0xb6, 0x1a,
+                       0x96, 0xc8,
+               },
+       },
+       {
+               sha1.New,
+               []byte{
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b,
+               },
+               []byte{
+                       0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                       0x08, 0x09, 0x0a, 0x0b, 0x0c,
+               },
+               []byte{
+                       0x9b, 0x6c, 0x18, 0xc4, 0x32, 0xa7, 0xbf, 0x8f,
+                       0x0e, 0x71, 0xc8, 0xeb, 0x88, 0xf4, 0xb3, 0x0b,
+                       0xaa, 0x2b, 0xa2, 0x43,
+               },
+               []byte{
+                       0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+                       0xf8, 0xf9,
+               },
+               []byte{
+                       0x08, 0x5a, 0x01, 0xea, 0x1b, 0x10, 0xf3, 0x69,
+                       0x33, 0x06, 0x8b, 0x56, 0xef, 0xa5, 0xad, 0x81,
+                       0xa4, 0xf1, 0x4b, 0x82, 0x2f, 0x5b, 0x09, 0x15,
+                       0x68, 0xa9, 0xcd, 0xd4, 0xf1, 0x55, 0xfd, 0xa2,
+                       0xc2, 0x2e, 0x42, 0x24, 0x78, 0xd3, 0x05, 0xf3,
+                       0xf8, 0x96,
+               },
+       },
+       {
+               sha1.New,
+               []byte{
+                       0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                       0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+                       0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+                       0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+                       0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+                       0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+                       0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+                       0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+                       0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
+                       0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+               },
+               []byte{
+                       0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+                       0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
+                       0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+                       0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
+                       0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+                       0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+                       0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
+                       0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+                       0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+                       0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+               },
+               []byte{
+                       0x8a, 0xda, 0xe0, 0x9a, 0x2a, 0x30, 0x70, 0x59,
+                       0x47, 0x8d, 0x30, 0x9b, 0x26, 0xc4, 0x11, 0x5a,
+                       0x22, 0x4c, 0xfa, 0xf6,
+               },
+               []byte{
+                       0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
+                       0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
+                       0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
+                       0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
+                       0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
+                       0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
+                       0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
+                       0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
+                       0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+                       0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
+               },
+               []byte{
+                       0x0b, 0xd7, 0x70, 0xa7, 0x4d, 0x11, 0x60, 0xf7,
+                       0xc9, 0xf1, 0x2c, 0xd5, 0x91, 0x2a, 0x06, 0xeb,
+                       0xff, 0x6a, 0xdc, 0xae, 0x89, 0x9d, 0x92, 0x19,
+                       0x1f, 0xe4, 0x30, 0x56, 0x73, 0xba, 0x2f, 0xfe,
+                       0x8f, 0xa3, 0xf1, 0xa4, 0xe5, 0xad, 0x79, 0xf3,
+                       0xf3, 0x34, 0xb3, 0xb2, 0x02, 0xb2, 0x17, 0x3c,
+                       0x48, 0x6e, 0xa3, 0x7c, 0xe3, 0xd3, 0x97, 0xed,
+                       0x03, 0x4c, 0x7f, 0x9d, 0xfe, 0xb1, 0x5c, 0x5e,
+                       0x92, 0x73, 0x36, 0xd0, 0x44, 0x1f, 0x4c, 0x43,
+                       0x00, 0xe2, 0xcf, 0xf0, 0xd0, 0x90, 0x0b, 0x52,
+                       0xd3, 0xb4,
+               },
+       },
+       {
+               sha1.New,
+               []byte{
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+               },
+               []byte{},
+               []byte{
+                       0xda, 0x8c, 0x8a, 0x73, 0xc7, 0xfa, 0x77, 0x28,
+                       0x8e, 0xc6, 0xf5, 0xe7, 0xc2, 0x97, 0x78, 0x6a,
+                       0xa0, 0xd3, 0x2d, 0x01,
+               },
+               []byte{},
+               []byte{
+                       0x0a, 0xc1, 0xaf, 0x70, 0x02, 0xb3, 0xd7, 0x61,
+                       0xd1, 0xe5, 0x52, 0x98, 0xda, 0x9d, 0x05, 0x06,
+                       0xb9, 0xae, 0x52, 0x05, 0x72, 0x20, 0xa3, 0x06,
+                       0xe0, 0x7b, 0x6b, 0x87, 0xe8, 0xdf, 0x21, 0xd0,
+                       0xea, 0x00, 0x03, 0x3d, 0xe0, 0x39, 0x84, 0xd3,
+                       0x49, 0x18,
+               },
+       },
+       {
+               sha1.New,
+               []byte{
+                       0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+                       0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+                       0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+               },
+               nil,
+               []byte{
+                       0x2a, 0xdc, 0xca, 0xda, 0x18, 0x77, 0x9e, 0x7c,
+                       0x20, 0x77, 0xad, 0x2e, 0xb1, 0x9d, 0x3f, 0x3e,
+                       0x73, 0x13, 0x85, 0xdd,
+               },
+               nil,
+               []byte{
+                       0x2c, 0x91, 0x11, 0x72, 0x04, 0xd7, 0x45, 0xf3,
+                       0x50, 0x0d, 0x63, 0x6a, 0x62, 0xf6, 0x4f, 0x0a,
+                       0xb3, 0xba, 0xe5, 0x48, 0xaa, 0x53, 0xd4, 0x23,
+                       0xb0, 0xd1, 0xf2, 0x7e, 0xbb, 0xa6, 0xf5, 0xe5,
+                       0x67, 0x3a, 0x08, 0x1d, 0x70, 0xcc, 0xe7, 0xac,
+                       0xfc, 0x48,
+               },
+       },
+}
+
+func TestHKDF(t *testing.T) {
+       for i, tt := range hkdfTests {
+               prk := hkdf.Extract(tt.hash, tt.master, tt.salt)
+               if !bytes.Equal(prk, tt.prk) {
+                       t.Errorf("test %d: incorrect PRK: have %v, need %v.", i, prk, tt.prk)
+               }
+
+               out := hkdf.Key(tt.hash, tt.master, tt.salt, tt.info, len(tt.out))
+               if !bytes.Equal(out, tt.out) {
+                       t.Errorf("test %d: incorrect output: have %v, need %v.", i, out, tt.out)
+               }
+
+               out = hkdf.Expand(tt.hash, prk, tt.info, len(tt.out))
+               if !bytes.Equal(out, tt.out) {
+                       t.Errorf("test %d: incorrect output from Expand: have %v, need %v.", i, out, tt.out)
+               }
+       }
+}
+
+func TestHKDFLimit(t *testing.T) {
+       hash := sha1.New
+       master := []byte{0x00, 0x01, 0x02, 0x03}
+       info := []byte{}
+
+       // The maximum output bytes should be extractable
+       limit := hash().Size() * 255
+       hkdf.Key(hash, master, nil, info, limit)
+
+       // Reading one more should panic
+       defer func() {
+               if err := recover(); err == nil {
+                       t.Error("expected panic")
+               }
+       }()
+       hkdf.Key(hash, master, nil, info, limit+1)
+}
+
+func Benchmark16ByteMD5Single(b *testing.B) {
+       benchmarkHKDFSingle(md5.New, 16, b)
+}
+
+func Benchmark20ByteSHA1Single(b *testing.B) {
+       benchmarkHKDFSingle(sha1.New, 20, b)
+}
+
+func Benchmark32ByteSHA256Single(b *testing.B) {
+       benchmarkHKDFSingle(sha256.New, 32, b)
+}
+
+func Benchmark64ByteSHA512Single(b *testing.B) {
+       benchmarkHKDFSingle(sha512.New, 64, b)
+}
+
+func benchmarkHKDFSingle(hasher func() hash.Hash, block int, b *testing.B) {
+       master := []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07}
+       salt := []byte{0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17}
+       info := []byte{0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27}
+
+       b.SetBytes(int64(block))
+       b.ResetTimer()
+
+       for i := 0; i < b.N; i++ {
+               hkdf.Key(hasher, master, salt, info, block)
+       }
+}

diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index bb48c7aa8533ece8ff54ac34bfb78d0213672e14..541bc1916f7a07dce4d1cde216b56a92f2077260 100644 (file)
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -461,6 +461,7 @@ var depsRules = `
        < crypto/internal/fips/sha3
        < crypto/internal/fips/hmac
        < crypto/internal/fips/check
+       < crypto/internal/fips/hkdf
        < FIPS;
 
        FIPS < crypto/internal/fips/check/checktest;