github.com/kaituanwang/hyperledger@v2.0.1+incompatible/bccsp/pkcs11/pkcs11.go (about)

     1  /*
     2  Copyright IBM Corp. All Rights Reserved.
     3  
     4  SPDX-License-Identifier: Apache-2.0
     5  */
     6  
     7  package pkcs11
     8  
     9  import (
    10  	"crypto/ecdsa"
    11  	"crypto/elliptic"
    12  	"crypto/sha256"
    13  	"encoding/asn1"
    14  	"encoding/hex"
    15  	"fmt"
    16  	"math/big"
    17  	"sync"
    18  
    19  	"github.com/miekg/pkcs11"
    20  	"go.uber.org/zap/zapcore"
    21  )
    22  
    23  func loadLib(lib, pin, label string) (*pkcs11.Ctx, uint, *pkcs11.SessionHandle, error) {
    24  	var slot uint
    25  	logger.Debugf("Loading pkcs11 library [%s]\n", lib)
    26  	if lib == "" {
    27  		return nil, slot, nil, fmt.Errorf("No PKCS11 library default")
    28  	}
    29  
    30  	ctx := pkcs11.New(lib)
    31  	if ctx == nil {
    32  		return nil, slot, nil, fmt.Errorf("Instantiate failed [%s]", lib)
    33  	}
    34  
    35  	ctx.Initialize()
    36  	slots, err := ctx.GetSlotList(true)
    37  	if err != nil {
    38  		return nil, slot, nil, fmt.Errorf("Could not get Slot List [%s]", err)
    39  	}
    40  	found := false
    41  	for _, s := range slots {
    42  		info, errToken := ctx.GetTokenInfo(s)
    43  		if errToken != nil {
    44  			continue
    45  		}
    46  		logger.Debugf("Looking for %s, found label %s\n", label, info.Label)
    47  		if label == info.Label {
    48  			found = true
    49  			slot = s
    50  			break
    51  		}
    52  	}
    53  	if !found {
    54  		return nil, slot, nil, fmt.Errorf("Could not find token with label %s", label)
    55  	}
    56  
    57  	var session pkcs11.SessionHandle
    58  	for i := 0; i < 10; i++ {
    59  		session, err = ctx.OpenSession(slot, pkcs11.CKF_SERIAL_SESSION|pkcs11.CKF_RW_SESSION)
    60  		if err != nil {
    61  			logger.Warningf("OpenSession failed, retrying [%s]\n", err)
    62  		} else {
    63  			break
    64  		}
    65  	}
    66  	if err != nil {
    67  		logger.Fatalf("OpenSession [%s]\n", err)
    68  	}
    69  	logger.Debugf("Created new pkcs11 session %+v on slot %d\n", session, slot)
    70  
    71  	if pin == "" {
    72  		return nil, slot, nil, fmt.Errorf("No PIN set")
    73  	}
    74  	err = ctx.Login(session, pkcs11.CKU_USER, pin)
    75  	if err != nil {
    76  		if err != pkcs11.Error(pkcs11.CKR_USER_ALREADY_LOGGED_IN) {
    77  			return nil, slot, nil, fmt.Errorf("Login failed [%s]", err)
    78  		}
    79  	}
    80  
    81  	return ctx, slot, &session, nil
    82  }
    83  
    84  func (csp *impl) getSession() (session pkcs11.SessionHandle) {
    85  	select {
    86  	case session = <-csp.sessions:
    87  		logger.Debugf("Reusing existing pkcs11 session %+v on slot %d\n", session, csp.slot)
    88  
    89  	default:
    90  		// cache is empty (or completely in use), create a new session
    91  		var s pkcs11.SessionHandle
    92  		var err error
    93  		for i := 0; i < 10; i++ {
    94  			s, err = csp.ctx.OpenSession(csp.slot, pkcs11.CKF_SERIAL_SESSION|pkcs11.CKF_RW_SESSION)
    95  			if err != nil {
    96  				logger.Warningf("OpenSession failed, retrying [%s]\n", err)
    97  			} else {
    98  				break
    99  			}
   100  		}
   101  		if err != nil {
   102  			panic(fmt.Errorf("OpenSession failed [%s]", err))
   103  		}
   104  		logger.Debugf("Created new pkcs11 session %+v on slot %d\n", s, csp.slot)
   105  		session = s
   106  	}
   107  	return session
   108  }
   109  
   110  func (csp *impl) returnSession(session pkcs11.SessionHandle) {
   111  	select {
   112  	case csp.sessions <- session:
   113  		// returned session back to session cache
   114  	default:
   115  		// have plenty of sessions in cache, dropping
   116  		csp.ctx.CloseSession(session)
   117  	}
   118  }
   119  
   120  // Look for an EC key by SKI, stored in CKA_ID
   121  func (csp *impl) getECKey(ski []byte) (pubKey *ecdsa.PublicKey, isPriv bool, err error) {
   122  	p11lib := csp.ctx
   123  	session := csp.getSession()
   124  	defer csp.returnSession(session)
   125  	isPriv = true
   126  	_, err = findKeyPairFromSKI(p11lib, session, ski, privateKeyType)
   127  	if err != nil {
   128  		isPriv = false
   129  		logger.Debugf("Private key not found [%s] for SKI [%s], looking for Public key", err, hex.EncodeToString(ski))
   130  	}
   131  
   132  	publicKey, err := findKeyPairFromSKI(p11lib, session, ski, publicKeyType)
   133  	if err != nil {
   134  		return nil, false, fmt.Errorf("Public key not found [%s] for SKI [%s]", err, hex.EncodeToString(ski))
   135  	}
   136  
   137  	ecpt, marshaledOid, err := ecPoint(p11lib, session, *publicKey)
   138  	if err != nil {
   139  		return nil, false, fmt.Errorf("Public key not found [%s] for SKI [%s]", err, hex.EncodeToString(ski))
   140  	}
   141  
   142  	curveOid := new(asn1.ObjectIdentifier)
   143  	_, err = asn1.Unmarshal(marshaledOid, curveOid)
   144  	if err != nil {
   145  		return nil, false, fmt.Errorf("Failed Unmarshaling Curve OID [%s]\n%s", err.Error(), hex.EncodeToString(marshaledOid))
   146  	}
   147  
   148  	curve := namedCurveFromOID(*curveOid)
   149  	if curve == nil {
   150  		return nil, false, fmt.Errorf("Cound not recognize Curve from OID")
   151  	}
   152  	x, y := elliptic.Unmarshal(curve, ecpt)
   153  	if x == nil {
   154  		return nil, false, fmt.Errorf("Failed Unmarshaling Public Key")
   155  	}
   156  
   157  	pubKey = &ecdsa.PublicKey{Curve: curve, X: x, Y: y}
   158  	return pubKey, isPriv, nil
   159  }
   160  
   161  // RFC 5480, 2.1.1.1. Named Curve
   162  //
   163  // secp224r1 OBJECT IDENTIFIER ::= {
   164  //   iso(1) identified-organization(3) certicom(132) curve(0) 33 }
   165  //
   166  // secp256r1 OBJECT IDENTIFIER ::= {
   167  //   iso(1) member-body(2) us(840) ansi-X9-62(10045) curves(3)
   168  //   prime(1) 7 }
   169  //
   170  // secp384r1 OBJECT IDENTIFIER ::= {
   171  //   iso(1) identified-organization(3) certicom(132) curve(0) 34 }
   172  //
   173  // secp521r1 OBJECT IDENTIFIER ::= {
   174  //   iso(1) identified-organization(3) certicom(132) curve(0) 35 }
   175  //
   176  var (
   177  	oidNamedCurveP224 = asn1.ObjectIdentifier{1, 3, 132, 0, 33}
   178  	oidNamedCurveP256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 3, 1, 7}
   179  	oidNamedCurveP384 = asn1.ObjectIdentifier{1, 3, 132, 0, 34}
   180  	oidNamedCurveP521 = asn1.ObjectIdentifier{1, 3, 132, 0, 35}
   181  )
   182  
   183  func namedCurveFromOID(oid asn1.ObjectIdentifier) elliptic.Curve {
   184  	switch {
   185  	case oid.Equal(oidNamedCurveP224):
   186  		return elliptic.P224()
   187  	case oid.Equal(oidNamedCurveP256):
   188  		return elliptic.P256()
   189  	case oid.Equal(oidNamedCurveP384):
   190  		return elliptic.P384()
   191  	case oid.Equal(oidNamedCurveP521):
   192  		return elliptic.P521()
   193  	}
   194  	return nil
   195  }
   196  
   197  func (csp *impl) generateECKey(curve asn1.ObjectIdentifier, ephemeral bool) (ski []byte, pubKey *ecdsa.PublicKey, err error) {
   198  	p11lib := csp.ctx
   199  	session := csp.getSession()
   200  	defer csp.returnSession(session)
   201  
   202  	id := nextIDCtr()
   203  	publabel := fmt.Sprintf("BCPUB%s", id.Text(16))
   204  	prvlabel := fmt.Sprintf("BCPRV%s", id.Text(16))
   205  
   206  	marshaledOID, err := asn1.Marshal(curve)
   207  	if err != nil {
   208  		return nil, nil, fmt.Errorf("Could not marshal OID [%s]", err.Error())
   209  	}
   210  
   211  	pubkeyT := []*pkcs11.Attribute{
   212  		pkcs11.NewAttribute(pkcs11.CKA_KEY_TYPE, pkcs11.CKK_EC),
   213  		pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_PUBLIC_KEY),
   214  		pkcs11.NewAttribute(pkcs11.CKA_TOKEN, !ephemeral),
   215  		pkcs11.NewAttribute(pkcs11.CKA_VERIFY, true),
   216  		pkcs11.NewAttribute(pkcs11.CKA_EC_PARAMS, marshaledOID),
   217  
   218  		pkcs11.NewAttribute(pkcs11.CKA_ID, publabel),
   219  		pkcs11.NewAttribute(pkcs11.CKA_LABEL, publabel),
   220  	}
   221  
   222  	prvkeyT := []*pkcs11.Attribute{
   223  		pkcs11.NewAttribute(pkcs11.CKA_KEY_TYPE, pkcs11.CKK_EC),
   224  		pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_PRIVATE_KEY),
   225  		pkcs11.NewAttribute(pkcs11.CKA_TOKEN, !ephemeral),
   226  		pkcs11.NewAttribute(pkcs11.CKA_PRIVATE, true),
   227  		pkcs11.NewAttribute(pkcs11.CKA_SIGN, true),
   228  
   229  		pkcs11.NewAttribute(pkcs11.CKA_ID, prvlabel),
   230  		pkcs11.NewAttribute(pkcs11.CKA_LABEL, prvlabel),
   231  
   232  		pkcs11.NewAttribute(pkcs11.CKA_EXTRACTABLE, false),
   233  		pkcs11.NewAttribute(pkcs11.CKA_SENSITIVE, true),
   234  	}
   235  
   236  	pub, prv, err := p11lib.GenerateKeyPair(session,
   237  		[]*pkcs11.Mechanism{pkcs11.NewMechanism(pkcs11.CKM_EC_KEY_PAIR_GEN, nil)},
   238  		pubkeyT, prvkeyT)
   239  
   240  	if err != nil {
   241  		return nil, nil, fmt.Errorf("P11: keypair generate failed [%s]", err)
   242  	}
   243  
   244  	ecpt, _, err := ecPoint(p11lib, session, pub)
   245  	if err != nil {
   246  		return nil, nil, fmt.Errorf("Error querying EC-point: [%s]", err)
   247  	}
   248  	hash := sha256.Sum256(ecpt)
   249  	ski = hash[:]
   250  
   251  	// set CKA_ID of the both keys to SKI(public key) and CKA_LABEL to hex string of SKI
   252  	setskiT := []*pkcs11.Attribute{
   253  		pkcs11.NewAttribute(pkcs11.CKA_ID, ski),
   254  		pkcs11.NewAttribute(pkcs11.CKA_LABEL, hex.EncodeToString(ski)),
   255  	}
   256  
   257  	logger.Infof("Generated new P11 key, SKI %x\n", ski)
   258  	err = p11lib.SetAttributeValue(session, pub, setskiT)
   259  	if err != nil {
   260  		return nil, nil, fmt.Errorf("P11: set-ID-to-SKI[public] failed [%s]", err)
   261  	}
   262  
   263  	err = p11lib.SetAttributeValue(session, prv, setskiT)
   264  	if err != nil {
   265  		return nil, nil, fmt.Errorf("P11: set-ID-to-SKI[private] failed [%s]", err)
   266  	}
   267  
   268  	//Set CKA_Modifible to false for both public key and private keys
   269  	if csp.immutable {
   270  		setCKAModifiable := []*pkcs11.Attribute{
   271  			pkcs11.NewAttribute(pkcs11.CKA_MODIFIABLE, false),
   272  		}
   273  
   274  		_, pubCopyerror := p11lib.CopyObject(session, pub, setCKAModifiable)
   275  		if pubCopyerror != nil {
   276  			return nil, nil, fmt.Errorf("P11: Public Key copy failed with error [%s] . Please contact your HSM vendor", pubCopyerror)
   277  		}
   278  
   279  		pubKeyDestroyError := p11lib.DestroyObject(session, pub)
   280  		if pubKeyDestroyError != nil {
   281  			return nil, nil, fmt.Errorf("P11: Public Key destroy failed with error [%s]. Please contact your HSM vendor", pubCopyerror)
   282  		}
   283  
   284  		_, prvCopyerror := p11lib.CopyObject(session, prv, setCKAModifiable)
   285  		if prvCopyerror != nil {
   286  			return nil, nil, fmt.Errorf("P11: Private Key copy failed with error [%s]. Please contact your HSM vendor", prvCopyerror)
   287  		}
   288  		prvKeyDestroyError := p11lib.DestroyObject(session, prv)
   289  		if pubKeyDestroyError != nil {
   290  			return nil, nil, fmt.Errorf("P11: Private Key destroy failed with error [%s]. Please contact your HSM vendor", prvKeyDestroyError)
   291  		}
   292  	}
   293  
   294  	nistCurve := namedCurveFromOID(curve)
   295  	if curve == nil {
   296  		return nil, nil, fmt.Errorf("Cound not recognize Curve from OID")
   297  	}
   298  	x, y := elliptic.Unmarshal(nistCurve, ecpt)
   299  	if x == nil {
   300  		return nil, nil, fmt.Errorf("Failed Unmarshaling Public Key")
   301  	}
   302  
   303  	pubGoKey := &ecdsa.PublicKey{Curve: nistCurve, X: x, Y: y}
   304  
   305  	if logger.IsEnabledFor(zapcore.DebugLevel) {
   306  		listAttrs(p11lib, session, prv)
   307  		listAttrs(p11lib, session, pub)
   308  	}
   309  
   310  	return ski, pubGoKey, nil
   311  }
   312  
   313  func (csp *impl) signP11ECDSA(ski []byte, msg []byte) (R, S *big.Int, err error) {
   314  	p11lib := csp.ctx
   315  	session := csp.getSession()
   316  	defer csp.returnSession(session)
   317  
   318  	privateKey, err := findKeyPairFromSKI(p11lib, session, ski, privateKeyType)
   319  	if err != nil {
   320  		return nil, nil, fmt.Errorf("Private key not found [%s]", err)
   321  	}
   322  
   323  	err = p11lib.SignInit(session, []*pkcs11.Mechanism{pkcs11.NewMechanism(pkcs11.CKM_ECDSA, nil)}, *privateKey)
   324  	if err != nil {
   325  		return nil, nil, fmt.Errorf("Sign-initialize  failed [%s]", err)
   326  	}
   327  
   328  	var sig []byte
   329  
   330  	sig, err = p11lib.Sign(session, msg)
   331  	if err != nil {
   332  		return nil, nil, fmt.Errorf("P11: sign failed [%s]", err)
   333  	}
   334  
   335  	R = new(big.Int)
   336  	S = new(big.Int)
   337  	R.SetBytes(sig[0 : len(sig)/2])
   338  	S.SetBytes(sig[len(sig)/2:])
   339  
   340  	return R, S, nil
   341  }
   342  
   343  func (csp *impl) verifyP11ECDSA(ski []byte, msg []byte, R, S *big.Int, byteSize int) (bool, error) {
   344  	p11lib := csp.ctx
   345  	session := csp.getSession()
   346  	defer csp.returnSession(session)
   347  
   348  	logger.Debugf("Verify ECDSA\n")
   349  
   350  	publicKey, err := findKeyPairFromSKI(p11lib, session, ski, publicKeyType)
   351  	if err != nil {
   352  		return false, fmt.Errorf("Public key not found [%s]", err)
   353  	}
   354  
   355  	r := R.Bytes()
   356  	s := S.Bytes()
   357  
   358  	// Pad front of R and S with Zeroes if needed
   359  	sig := make([]byte, 2*byteSize)
   360  	copy(sig[byteSize-len(r):byteSize], r)
   361  	copy(sig[2*byteSize-len(s):], s)
   362  
   363  	err = p11lib.VerifyInit(session, []*pkcs11.Mechanism{pkcs11.NewMechanism(pkcs11.CKM_ECDSA, nil)},
   364  		*publicKey)
   365  	if err != nil {
   366  		return false, fmt.Errorf("PKCS11: Verify-initialize [%s]", err)
   367  	}
   368  	err = p11lib.Verify(session, msg, sig)
   369  	if err == pkcs11.Error(pkcs11.CKR_SIGNATURE_INVALID) {
   370  		return false, nil
   371  	}
   372  	if err != nil {
   373  		return false, fmt.Errorf("PKCS11: Verify failed [%s]", err)
   374  	}
   375  
   376  	return true, nil
   377  }
   378  
   379  type keyType int8
   380  
   381  const (
   382  	publicKeyType keyType = iota
   383  	privateKeyType
   384  )
   385  
   386  func findKeyPairFromSKI(mod *pkcs11.Ctx, session pkcs11.SessionHandle, ski []byte, keyType keyType) (*pkcs11.ObjectHandle, error) {
   387  	ktype := pkcs11.CKO_PUBLIC_KEY
   388  	if keyType == privateKeyType {
   389  		ktype = pkcs11.CKO_PRIVATE_KEY
   390  	}
   391  
   392  	template := []*pkcs11.Attribute{
   393  		pkcs11.NewAttribute(pkcs11.CKA_CLASS, ktype),
   394  		pkcs11.NewAttribute(pkcs11.CKA_ID, ski),
   395  	}
   396  	if err := mod.FindObjectsInit(session, template); err != nil {
   397  		return nil, err
   398  	}
   399  
   400  	// single session instance, assume one hit only
   401  	objs, _, err := mod.FindObjects(session, 1)
   402  	if err != nil {
   403  		return nil, err
   404  	}
   405  	if err = mod.FindObjectsFinal(session); err != nil {
   406  		return nil, err
   407  	}
   408  
   409  	if len(objs) == 0 {
   410  		return nil, fmt.Errorf("Key not found [%s]", hex.Dump(ski))
   411  	}
   412  
   413  	return &objs[0], nil
   414  }
   415  
   416  // Fairly straightforward EC-point query, other than opencryptoki
   417  // mis-reporting length, including the 04 Tag of the field following
   418  // the SPKI in EP11-returned MACed publickeys:
   419  //
   420  // attr type 385/x181, length 66 b  -- SHOULD be 1+64
   421  // EC point:
   422  // 00000000  04 ce 30 31 6d 5a fd d3  53 2d 54 9a 27 54 d8 7c
   423  // 00000010  d9 80 35 91 09 2d 6f 06  5a 8e e3 cb c0 01 b7 c9
   424  // 00000020  13 5d 70 d4 e5 62 f2 1b  10 93 f7 d5 77 41 ba 9d
   425  // 00000030  93 3e 18 3e 00 c6 0a 0e  d2 36 cc 7f be 50 16 ef
   426  // 00000040  06 04
   427  //
   428  // cf. correct field:
   429  //   0  89: SEQUENCE {
   430  //   2  19:   SEQUENCE {
   431  //   4   7:     OBJECT IDENTIFIER ecPublicKey (1 2 840 10045 2 1)
   432  //  13   8:     OBJECT IDENTIFIER prime256v1 (1 2 840 10045 3 1 7)
   433  //        :     }
   434  //  23  66:   BIT STRING
   435  //        :     04 CE 30 31 6D 5A FD D3 53 2D 54 9A 27 54 D8 7C
   436  //        :     D9 80 35 91 09 2D 6F 06 5A 8E E3 CB C0 01 B7 C9
   437  //        :     13 5D 70 D4 E5 62 F2 1B 10 93 F7 D5 77 41 BA 9D
   438  //        :     93 3E 18 3E 00 C6 0A 0E D2 36 CC 7F BE 50 16 EF
   439  //        :     06
   440  //        :   }
   441  //
   442  // as a short-term workaround, remove the trailing byte if:
   443  //   - receiving an even number of bytes == 2*prime-coordinate +2 bytes
   444  //   - starting byte is 04: uncompressed EC point
   445  //   - trailing byte is 04: assume it belongs to the next OCTET STRING
   446  //
   447  // [mis-parsing encountered with v3.5.1, 2016-10-22]
   448  //
   449  // SoftHSM reports extra two bytes before the uncompressed point
   450  // 0x04 || <Length*2+1>
   451  //                 VV< Actual start of point
   452  // 00000000  04 41 04 6c c8 57 32 13  02 12 6a 19 23 1d 5a 64  |.A.l.W2...j.#.Zd|
   453  // 00000010  33 0c eb 75 4d e8 99 22  92 35 96 b2 39 58 14 1e  |3..uM..".5..9X..|
   454  // 00000020  19 de ef 32 46 50 68 02  24 62 36 db ed b1 84 7b  |...2FPh.$b6....{|
   455  // 00000030  93 d8 40 c3 d5 a6 b7 38  16 d2 35 0a 53 11 f9 51  |..@....8..5.S..Q|
   456  // 00000040  fc a7 16                                          |...|
   457  func ecPoint(p11lib *pkcs11.Ctx, session pkcs11.SessionHandle, key pkcs11.ObjectHandle) (ecpt, oid []byte, err error) {
   458  	template := []*pkcs11.Attribute{
   459  		pkcs11.NewAttribute(pkcs11.CKA_EC_POINT, nil),
   460  		pkcs11.NewAttribute(pkcs11.CKA_EC_PARAMS, nil),
   461  	}
   462  
   463  	attr, err := p11lib.GetAttributeValue(session, key, template)
   464  	if err != nil {
   465  		return nil, nil, fmt.Errorf("PKCS11: get(EC point) [%s]", err)
   466  	}
   467  
   468  	for _, a := range attr {
   469  		if a.Type == pkcs11.CKA_EC_POINT {
   470  			logger.Debugf("EC point: attr type %d/0x%x, len %d\n%s\n", a.Type, a.Type, len(a.Value), hex.Dump(a.Value))
   471  
   472  			// workarounds, see above
   473  			if ((len(a.Value) % 2) == 0) &&
   474  				(byte(0x04) == a.Value[0]) &&
   475  				(byte(0x04) == a.Value[len(a.Value)-1]) {
   476  				logger.Debugf("Detected opencryptoki bug, trimming trailing 0x04")
   477  				ecpt = a.Value[0 : len(a.Value)-1] // Trim trailing 0x04
   478  			} else if byte(0x04) == a.Value[0] && byte(0x04) == a.Value[2] {
   479  				logger.Debugf("Detected SoftHSM bug, trimming leading 0x04 0xXX")
   480  				ecpt = a.Value[2:len(a.Value)]
   481  			} else {
   482  				ecpt = a.Value
   483  			}
   484  		} else if a.Type == pkcs11.CKA_EC_PARAMS {
   485  			logger.Debugf("EC point: attr type %d/0x%x, len %d\n%s\n", a.Type, a.Type, len(a.Value), hex.Dump(a.Value))
   486  
   487  			oid = a.Value
   488  		}
   489  	}
   490  	if oid == nil || ecpt == nil {
   491  		return nil, nil, fmt.Errorf("CKA_EC_POINT not found, perhaps not an EC Key?")
   492  	}
   493  
   494  	return ecpt, oid, nil
   495  }
   496  
   497  func listAttrs(p11lib *pkcs11.Ctx, session pkcs11.SessionHandle, obj pkcs11.ObjectHandle) {
   498  	var cktype, ckclass uint
   499  	var ckaid, cklabel []byte
   500  
   501  	if p11lib == nil {
   502  		return
   503  	}
   504  
   505  	template := []*pkcs11.Attribute{
   506  		pkcs11.NewAttribute(pkcs11.CKA_CLASS, ckclass),
   507  		pkcs11.NewAttribute(pkcs11.CKA_KEY_TYPE, cktype),
   508  		pkcs11.NewAttribute(pkcs11.CKA_ID, ckaid),
   509  		pkcs11.NewAttribute(pkcs11.CKA_LABEL, cklabel),
   510  	}
   511  
   512  	// certain errors are tolerated, if value is missing
   513  	attr, err := p11lib.GetAttributeValue(session, obj, template)
   514  	if err != nil {
   515  		logger.Debugf("P11: get(attrlist) [%s]\n", err)
   516  	}
   517  
   518  	for _, a := range attr {
   519  		// Would be friendlier if the bindings provided a way convert Attribute hex to string
   520  		logger.Debugf("ListAttr: type %d/0x%x, length %d\n%s", a.Type, a.Type, len(a.Value), hex.Dump(a.Value))
   521  	}
   522  }
   523  
   524  var (
   525  	bigone  = new(big.Int).SetInt64(1)
   526  	idCtr   = new(big.Int)
   527  	idMutex sync.Mutex
   528  )
   529  
   530  func nextIDCtr() *big.Int {
   531  	idMutex.Lock()
   532  	idCtr = new(big.Int).Add(idCtr, bigone)
   533  	idMutex.Unlock()
   534  	return idCtr
   535  }