piv: support RSA PSS and add test for TLS 1.3 as a server and client

.github/workflows/test.yaml

@@ -11,7 +11,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: [1.18.x, 1.19.x]
+        go-version: [1.19.x, 1.20.x]
     name: Linux
     runs-on: ubuntu-latest
     steps:
@@ -22,16 +22,14 @@ jobs:
       id: go
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
-    - name: Install staticcheck
-      run: go install honnef.co/go/tools/cmd/[email protected]
     - name: Install libpcsc
       run: sudo apt-get install -y libpcsclite-dev pcscd pcsc-tools
     - name: Test
       run: "make test"
   build-windows:
     strategy:
       matrix:
-        go-version: [1.18.x, 1.19.x]
+        go-version: [1.19.x, 1.20.x]
     name: Windows
     runs-on: windows-latest
     steps:
@@ -42,8 +40,6 @@ jobs:
       id: go
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
-    - name: Install staticcheck
-      run: go install honnef.co/go/tools/cmd/[email protected]
     - name: Test
       run: "make build"
       env:

Makefile

@@ -1,11 +1,7 @@
 .PHONY: test
-test: lint
+test:
 	go test -v ./...
 
-.PHONY: lint
-lint:
-	staticcheck ./...
-
 .PHONY: build
-build: lint
+build:
 	go build ./...

piv/key.go

@@ -31,6 +31,8 @@ import (
 	"math/big"
 	"strconv"
 	"strings"
+
+	rsafork "github.com/go-piv/piv-go/third_party/rsa"
 )
 
 // errMismatchingAlgorithms is returned when a cryptographic operation
@@ -1072,7 +1074,7 @@ func (k *keyRSA) Public() crypto.PublicKey {
 
 func (k *keyRSA) Sign(rand io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
 	return k.auth.do(k.yk, k.pp, func(tx *scTx) ([]byte, error) {
-		return ykSignRSA(tx, k.slot, k.pub, digest, opts)
+		return ykSignRSA(tx, rand, k.slot, k.pub, digest, opts)
 	})
 }
 
@@ -1285,43 +1287,54 @@ func ykDecryptRSA(tx *scTx, slot Slot, pub *rsa.PublicKey, data []byte) ([]byte,
 // PKCS#1 v15 is largely informed by the standard library
 // https://github.com/golang/go/blob/go1.13.5/src/crypto/rsa/pkcs1v15.go
 
-func ykSignRSA(tx *scTx, slot Slot, pub *rsa.PublicKey, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
-	if _, ok := opts.(*rsa.PSSOptions); ok {
-		return nil, fmt.Errorf("rsassa-pss signatures not supported")
+func ykSignRSA(tx *scTx, rand io.Reader, slot Slot, pub *rsa.PublicKey, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
+	hash := opts.HashFunc()
+	if hash.Size() != len(digest) {
+		return nil, fmt.Errorf("input must be a hashed message")
 	}
 
 	alg, err := rsaAlg(pub)
 	if err != nil {
 		return nil, err
 	}
-	hash := opts.HashFunc()
-	if hash.Size() != len(digest) {
-		return nil, fmt.Errorf("input must be a hashed message")
-	}
-	prefix, ok := hashPrefixes[hash]
-	if !ok {
-		return nil, fmt.Errorf("unsupported hash algorithm: crypto.Hash(%d)", hash)
-	}
 
-	// https://tools.ietf.org/pdf/rfc2313.pdf#page=9
-	d := make([]byte, len(prefix)+len(digest))
-	copy(d[:len(prefix)], prefix)
-	copy(d[len(prefix):], digest)
+	var data []byte
+	if o, ok := opts.(*rsa.PSSOptions); ok {
+		salt, err := rsafork.NewSalt(rand, pub, hash, o)
+		if err != nil {
+			return nil, err
+		}
+		em, err := rsafork.EMSAPSSEncode(digest, pub, salt, hash.New())
+		if err != nil {
+			return nil, err
+		}
+		data = em
+	} else {
+		prefix, ok := hashPrefixes[hash]
+		if !ok {
+			return nil, fmt.Errorf("unsupported hash algorithm: crypto.Hash(%d)", hash)
+		}
+
+		// https://tools.ietf.org/pdf/rfc2313.pdf#page=9
+		d := make([]byte, len(prefix)+len(digest))
+		copy(d[:len(prefix)], prefix)
+		copy(d[len(prefix):], digest)
 
-	paddingLen := pub.Size() - 3 - len(d)
-	if paddingLen < 0 {
-		return nil, fmt.Errorf("message too large")
-	}
+		paddingLen := pub.Size() - 3 - len(d)
+		if paddingLen < 0 {
+			return nil, fmt.Errorf("message too large")
+		}
 
-	padding := make([]byte, paddingLen)
-	for i := range padding {
-		padding[i] = 0xff
-	}
+		padding := make([]byte, paddingLen)
+		for i := range padding {
+			padding[i] = 0xff
+		}
 
-	// https://tools.ietf.org/pdf/rfc2313.pdf#page=9
-	data := append([]byte{0x00, 0x01}, padding...)
-	data = append(data, 0x00)
-	data = append(data, d...)
+		// https://tools.ietf.org/pdf/rfc2313.pdf#page=9
+		data = append([]byte{0x00, 0x01}, padding...)
+		data = append(data, 0x00)
+		data = append(data, d...)
+	}
 
 	// https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-73-4.pdf#page=117
 	cmd := apdu{

piv/key_test.go

@@ -22,11 +22,14 @@ import (
 	"crypto/rand"
 	"crypto/rsa"
 	"crypto/sha256"
+	"crypto/tls"
 	"crypto/x509"
 	"crypto/x509/pkix"
 	"encoding/asn1"
 	"encoding/pem"
 	"errors"
+	"fmt"
+	"io"
 	"math/big"
 	"testing"
 	"time"
@@ -333,6 +336,179 @@ func TestYubiKeySignRSA(t *testing.T) {
 	}
 }
 
+func TestYubiKeySignRSAPSS(t *testing.T) {
+	tests := []struct {
+		name string
+		alg  Algorithm
+		long bool
+	}{
+		{"rsa1024", AlgorithmRSA1024, false},
+		{"rsa2048", AlgorithmRSA2048, true},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if test.long && testing.Short() {
+				t.Skip("skipping test in short mode")
+			}
+			yk, close := newTestYubiKey(t)
+			defer close()
+			slot := SlotAuthentication
+			key := Key{
+				Algorithm:   test.alg,
+				TouchPolicy: TouchPolicyNever,
+				PINPolicy:   PINPolicyNever,
+			}
+			pubKey, err := yk.GenerateKey(DefaultManagementKey, slot, key)
+			if err != nil {
+				t.Fatalf("generating key: %v", err)
+			}
+			pub, ok := pubKey.(*rsa.PublicKey)
+			if !ok {
+				t.Fatalf("public key is not an rsa key")
+			}
+			data := sha256.Sum256([]byte("hello"))
+			priv, err := yk.PrivateKey(slot, pub, KeyAuth{})
+			if err != nil {
+				t.Fatalf("getting private key: %v", err)
+			}
+			s, ok := priv.(crypto.Signer)
+			if !ok {
+				t.Fatalf("private key didn't implement crypto.Signer")
+			}
+
+			opt := &rsa.PSSOptions{Hash: crypto.SHA256}
+			out, err := s.Sign(rand.Reader, data[:], opt)
+			if err != nil {
+				t.Fatalf("signing failed: %v", err)
+			}
+			if err := rsa.VerifyPSS(pub, crypto.SHA256, data[:], out, opt); err != nil {
+				t.Errorf("failed to verify signature: %v", err)
+			}
+		})
+	}
+}
+
+func TestTLS13(t *testing.T) {
+	yk, close := newTestYubiKey(t)
+	defer close()
+	slot := SlotAuthentication
+	key := Key{
+		Algorithm:   AlgorithmRSA1024,
+		TouchPolicy: TouchPolicyNever,
+		PINPolicy:   PINPolicyNever,
+	}
+	pub, err := yk.GenerateKey(DefaultManagementKey, slot, key)
+	if err != nil {
+		t.Fatalf("generating key: %v", err)
+	}
+	priv, err := yk.PrivateKey(slot, pub, KeyAuth{})
+	if err != nil {
+		t.Fatalf("getting private key: %v", err)
+	}
+
+	tmpl := &x509.Certificate{
+		Subject:      pkix.Name{CommonName: "test"},
+		SerialNumber: big.NewInt(100),
+		NotBefore:    time.Now(),
+		NotAfter:     time.Now().Add(time.Hour),
+		DNSNames:     []string{"example.com"},
+		KeyUsage:     x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+		ExtKeyUsage: []x509.ExtKeyUsage{
+			x509.ExtKeyUsageClientAuth,
+			x509.ExtKeyUsageServerAuth,
+		},
+	}
+
+	rawCert, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, pub, priv)
+	if err != nil {
+		t.Fatalf("creating certificate: %v", err)
+	}
+	x509Cert, err := x509.ParseCertificate(rawCert)
+	if err != nil {
+		t.Fatalf("parsing cert: %v", err)
+	}
+	cert := tls.Certificate{
+		Certificate: [][]byte{rawCert},
+		PrivateKey:  priv,
+		SupportedSignatureAlgorithms: []tls.SignatureScheme{
+			tls.PSSWithSHA256,
+		},
+	}
+	pool := x509.NewCertPool()
+	pool.AddCert(x509Cert)
+
+	cliConf := &tls.Config{
+		Certificates: []tls.Certificate{cert},
+		RootCAs:      pool,
+		ServerName:   "example.com",
+		MinVersion:   tls.VersionTLS13,
+		MaxVersion:   tls.VersionTLS13,
+	}
+	srvConf := &tls.Config{
+		Certificates: []tls.Certificate{cert},
+		ClientCAs:    pool,
+		ClientAuth:   tls.RequireAndVerifyClientCert,
+		MinVersion:   tls.VersionTLS13,
+		MaxVersion:   tls.VersionTLS13,
+	}
+
+	srv, err := tls.Listen("tcp", "0.0.0.0:0", srvConf)
+	if err != nil {
+		t.Fatalf("creating tls listener: %v", err)
+	}
+	defer srv.Close()
+
+	errCh := make(chan error, 2)
+
+	want := []byte("hello, world")
+
+	go func() {
+		conn, err := srv.Accept()
+		if err != nil {
+			errCh <- fmt.Errorf("accepting conn: %v", err)
+			return
+		}
+		defer conn.Close()
+
+		got := make([]byte, len(want))
+		if _, err := io.ReadFull(conn, got); err != nil {
+			errCh <- fmt.Errorf("read data: %v", err)
+			return
+		}
+		if !bytes.Equal(want, got) {
+			errCh <- fmt.Errorf("unexpected value read: %s", got)
+			return
+		}
+		errCh <- nil
+	}()
+
+	go func() {
+		conn, err := tls.Dial("tcp", srv.Addr().String(), cliConf)
+		if err != nil {
+			errCh <- fmt.Errorf("dial: %v", err)
+			return
+		}
+		defer conn.Close()
+
+		if v := conn.ConnectionState().Version; v != tls.VersionTLS13 {
+			errCh <- fmt.Errorf("client got verison 0x%x, want=0x%x", v, tls.VersionTLS13)
+			return
+		}
+
+		if _, err := conn.Write(want); err != nil {
+			errCh <- fmt.Errorf("write: %v", err)
+			return
+		}
+		errCh <- nil
+	}()
+
+	for i := 0; i < 2; i++ {
+		if err := <-errCh; err != nil {
+			t.Fatalf("%v", err)
+		}
+	}
+}
+
 func TestYubiKeyDecryptRSA(t *testing.T) {
 	tests := []struct {
 		name string

third_party/rsa/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

third_party/rsa/README

@@ -0,0 +1,2 @@
+This directory contains a fork of internal crypto/rsa logic to allow computation
+of PSS padding.