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tpm2.go
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tpm2.go
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// Copyright (c) 2018, Google LLC All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package tpm2 supports direct communication with a TPM 2.0 device under Linux.
package tpm2
import (
"bytes"
"crypto"
"fmt"
"io"
"github.com/google/go-tpm/tpmutil"
)
// GetRandom gets random bytes from the TPM.
func GetRandom(rw io.ReadWriter, size uint16) ([]byte, error) {
resp, err := runCommand(rw, TagNoSessions, CmdGetRandom, size)
if err != nil {
return nil, err
}
var randBytes tpmutil.U16Bytes
if _, err := tpmutil.Unpack(resp, &randBytes); err != nil {
return nil, err
}
return randBytes, nil
}
// FlushContext removes an object or session under handle to be removed from
// the TPM. This must be called for any loaded handle to avoid out-of-memory
// errors in TPM.
func FlushContext(rw io.ReadWriter, handle tpmutil.Handle) error {
_, err := runCommand(rw, TagNoSessions, CmdFlushContext, handle)
return err
}
func encodeTPMLPCRSelection(sel ...PCRSelection) ([]byte, error) {
if len(sel) == 0 {
return tpmutil.Pack(uint32(0))
}
// PCR selection is a variable-size bitmask, where position of a set bit is
// the selected PCR index.
// Size of the bitmask in bytes is pre-pended. It should be at least
// sizeOfPCRSelect.
//
// For example, selecting PCRs 3 and 9 looks like:
// size(3) mask mask mask
// 00000011 00000000 00000001 00000100
var retBytes []byte
for _, s := range sel {
if len(s.PCRs) == 0 {
return tpmutil.Pack(uint32(0))
}
ts := tpmsPCRSelection{
Hash: s.Hash,
Size: sizeOfPCRSelect,
PCRs: make(tpmutil.RawBytes, sizeOfPCRSelect),
}
// s[i].PCRs parameter is indexes of PCRs, convert that to set bits.
for _, n := range s.PCRs {
if n >= 8*sizeOfPCRSelect {
return nil, fmt.Errorf("PCR index %d is out of range (exceeds maximum value %d)", n, 8*sizeOfPCRSelect-1)
}
byteNum := n / 8
bytePos := byte(1 << byte(n%8))
ts.PCRs[byteNum] |= bytePos
}
tmpBytes, err := tpmutil.Pack(ts)
if err != nil {
return nil, err
}
retBytes = append(retBytes, tmpBytes...)
}
tmpSize, err := tpmutil.Pack(uint32(len(sel)))
if err != nil {
return nil, err
}
retBytes = append(tmpSize, retBytes...)
return retBytes, nil
}
func decodeTPMLPCRSelection(buf *bytes.Buffer) ([]PCRSelection, error) {
var count uint32
var sel []PCRSelection
// This unpacks buffer which is of type TPMLPCRSelection
// and returns the count of TPMSPCRSelections.
if err := tpmutil.UnpackBuf(buf, &count); err != nil {
return sel, err
}
var ts tpmsPCRSelection
for i := 0; i < int(count); i++ {
var s PCRSelection
if err := tpmutil.UnpackBuf(buf, &ts.Hash, &ts.Size); err != nil {
return sel, err
}
ts.PCRs = make(tpmutil.RawBytes, ts.Size)
if _, err := buf.Read(ts.PCRs); err != nil {
return sel, err
}
s.Hash = ts.Hash
for j := 0; j < int(ts.Size); j++ {
for k := 0; k < 8; k++ {
set := ts.PCRs[j] & byte(1<<byte(k))
if set == 0 {
continue
}
s.PCRs = append(s.PCRs, 8*j+k)
}
}
sel = append(sel, s)
}
if len(sel) == 0 {
sel = append(sel, PCRSelection{
Hash: AlgUnknown,
})
}
return sel, nil
}
func decodeOneTPMLPCRSelection(buf *bytes.Buffer) (PCRSelection, error) {
sels, err := decodeTPMLPCRSelection(buf)
if err != nil {
return PCRSelection{}, err
}
if len(sels) != 1 {
return PCRSelection{}, fmt.Errorf("got %d TPMS_PCR_SELECTION items in TPML_PCR_SELECTION, expected 1", len(sels))
}
return sels[0], nil
}
func decodeReadPCRs(in []byte) (map[int][]byte, error) {
buf := bytes.NewBuffer(in)
var updateCounter uint32
if err := tpmutil.UnpackBuf(buf, &updateCounter); err != nil {
return nil, err
}
sel, err := decodeOneTPMLPCRSelection(buf)
if err != nil {
return nil, err
}
var digestCount uint32
if err = tpmutil.UnpackBuf(buf, &digestCount); err != nil {
return nil, fmt.Errorf("decoding TPML_DIGEST length: %v", err)
}
if int(digestCount) != len(sel.PCRs) {
return nil, fmt.Errorf("received %d PCRs but %d digests", len(sel.PCRs), digestCount)
}
vals := make(map[int][]byte)
for _, pcr := range sel.PCRs {
var val tpmutil.U16Bytes
if err = tpmutil.UnpackBuf(buf, &val); err != nil {
return nil, fmt.Errorf("decoding TPML_DIGEST item: %v", err)
}
vals[pcr] = val
}
return vals, nil
}
// ReadPCRs reads PCR values from the TPM.
// This is only a wrapper over TPM2_PCR_Read() call, thus can only return
// at most 8 PCRs digests.
func ReadPCRs(rw io.ReadWriter, sel PCRSelection) (map[int][]byte, error) {
Cmd, err := encodeTPMLPCRSelection(sel)
if err != nil {
return nil, err
}
resp, err := runCommand(rw, TagNoSessions, CmdPCRRead, tpmutil.RawBytes(Cmd))
if err != nil {
return nil, err
}
return decodeReadPCRs(resp)
}
func decodeReadClock(in []byte) (uint64, uint64, error) {
var curTime, curClock uint64
if _, err := tpmutil.Unpack(in, &curTime, &curClock); err != nil {
return 0, 0, err
}
return curTime, curClock, nil
}
// ReadClock returns current clock values from the TPM.
//
// First return value is time in milliseconds since TPM was initialized (since
// system startup).
//
// Second return value is time in milliseconds since TPM reset (since Storage
// Primary Seed is changed).
func ReadClock(rw io.ReadWriter) (uint64, uint64, error) {
resp, err := runCommand(rw, TagNoSessions, CmdReadClock)
if err != nil {
return 0, 0, err
}
return decodeReadClock(resp)
}
func decodeGetCapability(in []byte) ([]interface{}, bool, error) {
var moreData byte
var capReported Capability
buf := bytes.NewBuffer(in)
if err := tpmutil.UnpackBuf(buf, &moreData, &capReported); err != nil {
return nil, false, err
}
switch capReported {
case CapabilityHandles:
var numHandles uint32
if err := tpmutil.UnpackBuf(buf, &numHandles); err != nil {
return nil, false, fmt.Errorf("could not unpack handle count: %v", err)
}
var handles []interface{}
for i := 0; i < int(numHandles); i++ {
var handle tpmutil.Handle
if err := tpmutil.UnpackBuf(buf, &handle); err != nil {
return nil, false, fmt.Errorf("could not unpack handle: %v", err)
}
handles = append(handles, handle)
}
return handles, moreData > 0, nil
case CapabilityAlgs:
var numAlgs uint32
if err := tpmutil.UnpackBuf(buf, &numAlgs); err != nil {
return nil, false, fmt.Errorf("could not unpack algorithm count: %v", err)
}
var algs []interface{}
for i := 0; i < int(numAlgs); i++ {
var alg AlgorithmDescription
if err := tpmutil.UnpackBuf(buf, &alg); err != nil {
return nil, false, fmt.Errorf("could not unpack algorithm description: %v", err)
}
algs = append(algs, alg)
}
return algs, moreData > 0, nil
case CapabilityTPMProperties:
var numProps uint32
if err := tpmutil.UnpackBuf(buf, &numProps); err != nil {
return nil, false, fmt.Errorf("could not unpack fixed properties count: %v", err)
}
var props []interface{}
for i := 0; i < int(numProps); i++ {
var prop TaggedProperty
if err := tpmutil.UnpackBuf(buf, &prop); err != nil {
return nil, false, fmt.Errorf("could not unpack tagged property: %v", err)
}
props = append(props, prop)
}
return props, moreData > 0, nil
case CapabilityPCRs:
var pcrss []interface{}
pcrs, err := decodeTPMLPCRSelection(buf)
if err != nil {
return nil, false, fmt.Errorf("could not unpack pcr selection: %v", err)
}
for i := 0; i < len(pcrs); i++ {
pcrss = append(pcrss, pcrs[i])
}
return pcrss, moreData > 0, nil
default:
return nil, false, fmt.Errorf("unsupported capability %v", capReported)
}
}
// GetCapability returns various information about the TPM state.
//
// Currently only CapabilityHandles (list active handles) and CapabilityAlgs
// (list supported algorithms) are supported. CapabilityHandles will return
// a []tpmutil.Handle for vals, CapabilityAlgs will return
// []AlgorithmDescription.
//
// moreData is true if the TPM indicated that more data is available. Follow
// the spec for the capability in question on how to query for more data.
func GetCapability(rw io.ReadWriter, capa Capability, count, property uint32) (vals []interface{}, moreData bool, err error) {
resp, err := runCommand(rw, TagNoSessions, CmdGetCapability, capa, property, count)
if err != nil {
return nil, false, err
}
return decodeGetCapability(resp)
}
// GetManufacturer returns the manufacturer ID
func GetManufacturer(rw io.ReadWriter) ([]byte, error) {
caps, _, err := GetCapability(rw, CapabilityTPMProperties, 1, uint32(Manufacturer))
if err != nil {
return nil, err
}
prop := caps[0].(TaggedProperty)
return tpmutil.Pack(prop.Value)
}
func encodeAuthArea(sections ...AuthCommand) ([]byte, error) {
var res tpmutil.RawBytes
for _, s := range sections {
buf, err := tpmutil.Pack(s)
if err != nil {
return nil, err
}
res = append(res, buf...)
}
size, err := tpmutil.Pack(uint32(len(res)))
if err != nil {
return nil, err
}
return concat(size, res)
}
func encodePCREvent(pcr tpmutil.Handle, eventData []byte) ([]byte, error) {
ha, err := tpmutil.Pack(pcr)
if err != nil {
return nil, err
}
auth, err := encodeAuthArea(AuthCommand{Session: HandlePasswordSession, Attributes: AttrContinueSession, Auth: EmptyAuth})
if err != nil {
return nil, err
}
event, err := tpmutil.Pack(tpmutil.U16Bytes(eventData))
if err != nil {
return nil, err
}
return concat(ha, auth, event)
}
// PCREvent writes an update to the specified PCR.
func PCREvent(rw io.ReadWriter, pcr tpmutil.Handle, eventData []byte) error {
Cmd, err := encodePCREvent(pcr, eventData)
if err != nil {
return err
}
_, err = runCommand(rw, TagSessions, CmdPCREvent, tpmutil.RawBytes(Cmd))
return err
}
func encodeSensitiveArea(s tpmsSensitiveCreate) ([]byte, error) {
// TPMS_SENSITIVE_CREATE
buf, err := tpmutil.Pack(s)
if err != nil {
return nil, err
}
// TPM2B_SENSITIVE_CREATE
return tpmutil.Pack(tpmutil.U16Bytes(buf))
}
// encodeCreate works for both TPM2_Create and TPM2_CreatePrimary.
func encodeCreate(owner tpmutil.Handle, sel PCRSelection, auth AuthCommand, ownerPassword string, sensitiveData []byte, pub Public) ([]byte, error) {
parent, err := tpmutil.Pack(owner)
if err != nil {
return nil, err
}
encodedAuth, err := encodeAuthArea(auth)
if err != nil {
return nil, err
}
inSensitive, err := encodeSensitiveArea(tpmsSensitiveCreate{
UserAuth: []byte(ownerPassword),
Data: sensitiveData,
})
if err != nil {
return nil, err
}
inPublic, err := pub.Encode()
if err != nil {
return nil, err
}
publicBlob, err := tpmutil.Pack(tpmutil.U16Bytes(inPublic))
if err != nil {
return nil, err
}
outsideInfo, err := tpmutil.Pack(tpmutil.U16Bytes(nil))
if err != nil {
return nil, err
}
creationPCR, err := encodeTPMLPCRSelection(sel)
if err != nil {
return nil, err
}
return concat(
parent,
encodedAuth,
inSensitive,
publicBlob,
outsideInfo,
creationPCR,
)
}
func decodeCreatePrimary(in []byte) (handle tpmutil.Handle, public, creationData, creationHash tpmutil.U16Bytes, ticket Ticket, creationName tpmutil.U16Bytes, err error) {
var paramSize uint32
buf := bytes.NewBuffer(in)
// Handle and auth data.
if err := tpmutil.UnpackBuf(buf, &handle, ¶mSize); err != nil {
return 0, nil, nil, nil, Ticket{}, nil, fmt.Errorf("decoding handle, paramSize: %v", err)
}
if err := tpmutil.UnpackBuf(buf, &public, &creationData, &creationHash, &ticket, &creationName); err != nil {
return 0, nil, nil, nil, Ticket{}, nil, fmt.Errorf("decoding public, creationData, creationHash, ticket, creationName: %v", err)
}
if _, err := DecodeCreationData(creationData); err != nil {
return 0, nil, nil, nil, Ticket{}, nil, fmt.Errorf("parsing CreationData: %v", err)
}
return handle, public, creationData, creationHash, ticket, creationName, err
}
// CreatePrimary initializes the primary key in a given hierarchy.
// The second return value is the public part of the generated key.
func CreatePrimary(rw io.ReadWriter, owner tpmutil.Handle, sel PCRSelection, parentPassword, ownerPassword string, p Public) (tpmutil.Handle, crypto.PublicKey, error) {
hnd, public, _, _, _, _, err := CreatePrimaryEx(rw, owner, sel, parentPassword, ownerPassword, p)
if err != nil {
return 0, nil, err
}
pub, err := DecodePublic(public)
if err != nil {
return 0, nil, fmt.Errorf("parsing public: %v", err)
}
pubKey, err := pub.Key()
if err != nil {
return 0, nil, fmt.Errorf("extracting cryto.PublicKey from Public part of primary key: %v", err)
}
return hnd, pubKey, err
}
// CreatePrimaryEx initializes the primary key in a given hierarchy.
// This function differs from CreatePrimary in that all response elements
// are returned, and they are returned in relatively raw form.
func CreatePrimaryEx(rw io.ReadWriter, owner tpmutil.Handle, sel PCRSelection, parentPassword, ownerPassword string, pub Public) (keyHandle tpmutil.Handle, public, creationData, creationHash []byte, ticket Ticket, creationName []byte, err error) {
auth := AuthCommand{Session: HandlePasswordSession, Attributes: AttrContinueSession, Auth: []byte(parentPassword)}
Cmd, err := encodeCreate(owner, sel, auth, ownerPassword, nil /*inSensitive*/, pub)
if err != nil {
return 0, nil, nil, nil, Ticket{}, nil, err
}
resp, err := runCommand(rw, TagSessions, CmdCreatePrimary, tpmutil.RawBytes(Cmd))
if err != nil {
return 0, nil, nil, nil, Ticket{}, nil, err
}
return decodeCreatePrimary(resp)
}
// CreatePrimaryRawTemplate is CreatePrimary, but with the public template
// (TPMT_PUBLIC) provided pre-encoded. This is commonly used with key templates
// stored in NV RAM.
func CreatePrimaryRawTemplate(rw io.ReadWriter, owner tpmutil.Handle, sel PCRSelection, parentPassword, ownerPassword string, public []byte) (tpmutil.Handle, crypto.PublicKey, error) {
pub, err := DecodePublic(public)
if err != nil {
return 0, nil, fmt.Errorf("parsing input template: %v", err)
}
return CreatePrimary(rw, owner, sel, parentPassword, ownerPassword, pub)
}
func decodeReadPublic(in []byte) (Public, []byte, []byte, error) {
var resp struct {
Public tpmutil.U16Bytes
Name tpmutil.U16Bytes
QualifiedName tpmutil.U16Bytes
}
if _, err := tpmutil.Unpack(in, &resp); err != nil {
return Public{}, nil, nil, err
}
pub, err := DecodePublic(resp.Public)
if err != nil {
return Public{}, nil, nil, err
}
return pub, resp.Name, resp.QualifiedName, nil
}
// ReadPublic reads the public part of the object under handle.
// Returns the public data, name and qualified name.
func ReadPublic(rw io.ReadWriter, handle tpmutil.Handle) (Public, []byte, []byte, error) {
resp, err := runCommand(rw, TagNoSessions, CmdReadPublic, handle)
if err != nil {
return Public{}, nil, nil, err
}
return decodeReadPublic(resp)
}
func decodeCreate(in []byte) (private, public, creationData, creationHash tpmutil.U16Bytes, creationTicket Ticket, err error) {
buf := bytes.NewBuffer(in)
var paramSize uint32
if err := tpmutil.UnpackBuf(buf, ¶mSize, &private, &public, &creationData, &creationHash, &creationTicket); err != nil {
return nil, nil, nil, nil, Ticket{}, fmt.Errorf("decoding Handle, Private, Public, CreationData, CreationHash, CreationTicket: %v", err)
}
if err != nil {
return nil, nil, nil, nil, Ticket{}, fmt.Errorf("decoding CreationTicket: %v", err)
}
if _, err := DecodeCreationData(creationData); err != nil {
return nil, nil, nil, nil, Ticket{}, fmt.Errorf("decoding CreationData: %v", err)
}
return private, public, creationData, creationHash, creationTicket, nil
}
func create(rw io.ReadWriter, parentHandle tpmutil.Handle, auth AuthCommand, objectPassword string, sensitiveData []byte, pub Public, pcrSelection PCRSelection) (private, public, creationData, creationHash []byte, creationTicket Ticket, err error) {
cmd, err := encodeCreate(parentHandle, pcrSelection, auth, objectPassword, sensitiveData, pub)
if err != nil {
return nil, nil, nil, nil, Ticket{}, err
}
resp, err := runCommand(rw, TagSessions, CmdCreate, tpmutil.RawBytes(cmd))
if err != nil {
return nil, nil, nil, nil, Ticket{}, err
}
return decodeCreate(resp)
}
// CreateKey creates a new key pair under the owner handle.
// Returns private key and public key blobs as well as the
// creation data, a hash of said data and the creation ticket.
func CreateKey(rw io.ReadWriter, owner tpmutil.Handle, sel PCRSelection, parentPassword, ownerPassword string, pub Public) (private, public, creationData, creationHash []byte, creationTicket Ticket, err error) {
auth := AuthCommand{Session: HandlePasswordSession, Attributes: AttrContinueSession, Auth: []byte(parentPassword)}
return create(rw, owner, auth, ownerPassword, nil /*inSensitive*/, pub, sel)
}
// CreateKeyUsingAuth creates a new key pair under the owner handle using the
// provided AuthCommand. Returns private key and public key blobs as well as
// the creation data, a hash of said data, and the creation ticket.
func CreateKeyUsingAuth(rw io.ReadWriter, owner tpmutil.Handle, sel PCRSelection, auth AuthCommand, ownerPassword string, pub Public) (private, public, creationData, creationHash []byte, creationTicket Ticket, err error) {
return create(rw, owner, auth, ownerPassword, nil /*inSensitive*/, pub, sel)
}
// CreateKeyWithSensitive is very similar to CreateKey, except
// that it can take in a piece of sensitive data.
func CreateKeyWithSensitive(rw io.ReadWriter, owner tpmutil.Handle, sel PCRSelection, parentPassword, ownerPassword string, pub Public, sensitive []byte) (private, public, creationData, creationHash []byte, creationTicket Ticket, err error) {
auth := AuthCommand{Session: HandlePasswordSession, Attributes: AttrContinueSession, Auth: []byte(parentPassword)}
return create(rw, owner, auth, ownerPassword, sensitive, pub, sel)
}
// Seal creates a data blob object that seals the sensitive data under a parent and with a
// password and auth policy. Access to the parent must be available with a simple password.
// Returns private and public portions of the created object.
func Seal(rw io.ReadWriter, parentHandle tpmutil.Handle, parentPassword, objectPassword string, objectAuthPolicy []byte, sensitiveData []byte) ([]byte, []byte, error) {
inPublic := Public{
Type: AlgKeyedHash,
NameAlg: AlgSHA256,
Attributes: FlagFixedTPM | FlagFixedParent,
AuthPolicy: objectAuthPolicy,
}
auth := AuthCommand{Session: HandlePasswordSession, Attributes: AttrContinueSession, Auth: []byte(parentPassword)}
private, public, _, _, _, err := create(rw, parentHandle, auth, objectPassword, sensitiveData, inPublic, PCRSelection{})
if err != nil {
return nil, nil, err
}
return private, public, nil
}
func encodeImport(parentHandle tpmutil.Handle, auth AuthCommand, publicBlob, privateBlob, symSeed, encryptionKey tpmutil.U16Bytes, sym *SymScheme) ([]byte, error) {
ph, err := tpmutil.Pack(parentHandle)
if err != nil {
return nil, err
}
encodedAuth, err := encodeAuthArea(auth)
if err != nil {
return nil, err
}
data, err := tpmutil.Pack(encryptionKey, publicBlob, privateBlob, symSeed)
if err != nil {
return nil, err
}
encodedScheme, err := sym.encode()
if err != nil {
return nil, err
}
return concat(ph, encodedAuth, data, encodedScheme)
}
func decodeImport(resp []byte) ([]byte, error) {
var paramSize uint32
var outPrivate tpmutil.U16Bytes
_, err := tpmutil.Unpack(resp, ¶mSize, &outPrivate)
return outPrivate, err
}
// Import allows a user to import a key created on a different computer
// or in a different TPM. The publicBlob and privateBlob must always be
// provided. symSeed should be non-nil iff an "outer wrapper" is used. Both of
// encryptionKey and sym should be non-nil iff an "inner wrapper" is used.
func Import(rw io.ReadWriter, parentHandle tpmutil.Handle, auth AuthCommand, publicBlob, privateBlob, symSeed, encryptionKey []byte, sym *SymScheme) ([]byte, error) {
Cmd, err := encodeImport(parentHandle, auth, publicBlob, privateBlob, symSeed, encryptionKey, sym)
if err != nil {
return nil, err
}
resp, err := runCommand(rw, TagSessions, CmdImport, tpmutil.RawBytes(Cmd))
if err != nil {
return nil, err
}
return decodeImport(resp)
}
func encodeLoad(parentHandle tpmutil.Handle, auth AuthCommand, publicBlob, privateBlob tpmutil.U16Bytes) ([]byte, error) {
ah, err := tpmutil.Pack(parentHandle)
if err != nil {
return nil, err
}
encodedAuth, err := encodeAuthArea(auth)
if err != nil {
return nil, err
}
params, err := tpmutil.Pack(privateBlob, publicBlob)
if err != nil {
return nil, err
}
return concat(ah, encodedAuth, params)
}
func decodeLoad(in []byte) (tpmutil.Handle, []byte, error) {
var handle tpmutil.Handle
var paramSize uint32
var name tpmutil.U16Bytes
if _, err := tpmutil.Unpack(in, &handle, ¶mSize, &name); err != nil {
return 0, nil, err
}
// Re-encode the name as a TPM2B_NAME so it can be parsed by DecodeName().
b := &bytes.Buffer{}
if err := name.TPMMarshal(b); err != nil {
return 0, nil, err
}
return handle, b.Bytes(), nil
}
// Load loads public/private blobs into an object in the TPM.
// Returns loaded object handle and its name.
func Load(rw io.ReadWriter, parentHandle tpmutil.Handle, parentAuth string, publicBlob, privateBlob []byte) (tpmutil.Handle, []byte, error) {
auth := AuthCommand{Session: HandlePasswordSession, Attributes: AttrContinueSession, Auth: []byte(parentAuth)}
return LoadUsingAuth(rw, parentHandle, auth, publicBlob, privateBlob)
}
// LoadUsingAuth loads public/private blobs into an object in the TPM using the
// provided AuthCommand. Returns loaded object handle and its name.
func LoadUsingAuth(rw io.ReadWriter, parentHandle tpmutil.Handle, auth AuthCommand, publicBlob, privateBlob []byte) (tpmutil.Handle, []byte, error) {
Cmd, err := encodeLoad(parentHandle, auth, publicBlob, privateBlob)
if err != nil {
return 0, nil, err
}
resp, err := runCommand(rw, TagSessions, CmdLoad, tpmutil.RawBytes(Cmd))
if err != nil {
return 0, nil, err
}
return decodeLoad(resp)
}
func encodeLoadExternal(pub Public, private Private, hierarchy tpmutil.Handle) ([]byte, error) {
privateBlob, err := private.Encode()
if err != nil {
return nil, err
}
publicBlob, err := pub.Encode()
if err != nil {
return nil, err
}
return tpmutil.Pack(tpmutil.U16Bytes(privateBlob), tpmutil.U16Bytes(publicBlob), hierarchy)
}
func decodeLoadExternal(in []byte) (tpmutil.Handle, []byte, error) {
var handle tpmutil.Handle
var name tpmutil.U16Bytes
if _, err := tpmutil.Unpack(in, &handle, &name); err != nil {
return 0, nil, err
}
return handle, name, nil
}
// LoadExternal loads a public (and optionally a private) key into an object in
// the TPM. Returns loaded object handle and its name.
func LoadExternal(rw io.ReadWriter, pub Public, private Private, hierarchy tpmutil.Handle) (tpmutil.Handle, []byte, error) {
Cmd, err := encodeLoadExternal(pub, private, hierarchy)
if err != nil {
return 0, nil, err
}
resp, err := runCommand(rw, TagNoSessions, CmdLoadExternal, tpmutil.RawBytes(Cmd))
if err != nil {
return 0, nil, err
}
handle, name, err := decodeLoadExternal(resp)
if err != nil {
return 0, nil, err
}
return handle, name, nil
}
// PolicyPassword sets password authorization requirement on the object.
func PolicyPassword(rw io.ReadWriter, handle tpmutil.Handle) error {
_, err := runCommand(rw, TagNoSessions, CmdPolicyPassword, handle)
return err
}
func encodePolicySecret(entityHandle tpmutil.Handle, entityAuth AuthCommand, policyHandle tpmutil.Handle, policyNonce, cpHash, policyRef tpmutil.U16Bytes, expiry int32) ([]byte, error) {
auth, err := encodeAuthArea(entityAuth)
if err != nil {
return nil, err
}
handles, err := tpmutil.Pack(entityHandle, policyHandle)
if err != nil {
return nil, err
}
params, err := tpmutil.Pack(policyNonce, cpHash, policyRef, expiry)
if err != nil {
return nil, err
}
return concat(handles, auth, params)
}
func decodePolicySecret(in []byte) (*Ticket, error) {
buf := bytes.NewBuffer(in)
var paramSize uint32
var timeout tpmutil.U16Bytes
if err := tpmutil.UnpackBuf(buf, ¶mSize, &timeout); err != nil {
return nil, fmt.Errorf("decoding timeout: %v", err)
}
var t Ticket
if err := tpmutil.UnpackBuf(buf, &t); err != nil {
return nil, fmt.Errorf("decoding ticket: %v", err)
}
return &t, nil
}
// PolicySecret sets a secret authorization requirement on the provided entity.
// If expiry is non-zero, the authorization is valid for expiry seconds.
func PolicySecret(rw io.ReadWriter, entityHandle tpmutil.Handle, entityAuth AuthCommand, policyHandle tpmutil.Handle, policyNonce, cpHash, policyRef []byte, expiry int32) (*Ticket, error) {
Cmd, err := encodePolicySecret(entityHandle, entityAuth, policyHandle, policyNonce, cpHash, policyRef, expiry)
if err != nil {
return nil, err
}
resp, err := runCommand(rw, TagSessions, CmdPolicySecret, tpmutil.RawBytes(Cmd))
if err != nil {
return nil, err
}
// Tickets are only provided if expiry is set.
if expiry != 0 {
return decodePolicySecret(resp)
}
return nil, nil
}
func encodePolicyPCR(session tpmutil.Handle, expectedDigest tpmutil.U16Bytes, sel PCRSelection) ([]byte, error) {
params, err := tpmutil.Pack(session, expectedDigest)
if err != nil {
return nil, err
}
pcrs, err := encodeTPMLPCRSelection(sel)
if err != nil {
return nil, err
}
return concat(params, pcrs)
}
// PolicyPCR sets PCR state binding for authorization on a session.
//
// expectedDigest is optional. When specified, it's compared against the digest
// of PCRs matched by sel.
//
// Note that expectedDigest must be a *digest* of the expected PCR value. You
// must compute the digest manually. ReadPCR returns raw PCR values, not their
// digests.
// If you wish to select multiple PCRs, concatenate their values before
// computing the digest. See "TPM 2.0 Part 1, Selecting Multiple PCR".
func PolicyPCR(rw io.ReadWriter, session tpmutil.Handle, expectedDigest []byte, sel PCRSelection) error {
Cmd, err := encodePolicyPCR(session, expectedDigest, sel)
if err != nil {
return err
}
_, err = runCommand(rw, TagNoSessions, CmdPolicyPCR, tpmutil.RawBytes(Cmd))
return err
}
// PolicyOr compares PolicySession→Digest against the list of provided values.
// If the current Session→Digest does not match any value in the list,
// the TPM shall return TPM_RC_VALUE. Otherwise, the TPM will reset policySession→Digest
// to a Zero Digest. Then policySession→Digest is extended by the concatenation of
// TPM_CC_PolicyOR and the concatenation of all of the digests.
func PolicyOr(rw io.ReadWriter, session tpmutil.Handle, digests TPMLDigest) error {
d, err := digests.Encode()
if err != nil {
return err
}
data, err := tpmutil.Pack(session, d)
if err != nil {
return err
}
_, err = runCommand(rw, TagNoSessions, CmdPolicyOr, data)
return err
}
// PolicyGetDigest returns the current policyDigest of the session.
func PolicyGetDigest(rw io.ReadWriter, handle tpmutil.Handle) ([]byte, error) {
resp, err := runCommand(rw, TagNoSessions, CmdPolicyGetDigest, handle)
if err != nil {
return nil, err
}
var digest tpmutil.U16Bytes
_, err = tpmutil.Unpack(resp, &digest)
return digest, err
}
func encodeStartAuthSession(tpmKey, bindKey tpmutil.Handle, nonceCaller, secret tpmutil.U16Bytes, se SessionType, sym, hashAlg Algorithm) ([]byte, error) {
ha, err := tpmutil.Pack(tpmKey, bindKey)
if err != nil {
return nil, err
}
params, err := tpmutil.Pack(nonceCaller, secret, se, sym, hashAlg)
if err != nil {
return nil, err
}
return concat(ha, params)
}
func decodeStartAuthSession(in []byte) (tpmutil.Handle, []byte, error) {
var handle tpmutil.Handle
var nonce tpmutil.U16Bytes
if _, err := tpmutil.Unpack(in, &handle, &nonce); err != nil {
return 0, nil, err
}
return handle, nonce, nil
}
// StartAuthSession initializes a session object.
// Returns session handle and the initial nonce from the TPM.
func StartAuthSession(rw io.ReadWriter, tpmKey, bindKey tpmutil.Handle, nonceCaller, secret []byte, se SessionType, sym, hashAlg Algorithm) (tpmutil.Handle, []byte, error) {
Cmd, err := encodeStartAuthSession(tpmKey, bindKey, nonceCaller, secret, se, sym, hashAlg)
if err != nil {
return 0, nil, err
}
resp, err := runCommand(rw, TagNoSessions, CmdStartAuthSession, tpmutil.RawBytes(Cmd))
if err != nil {
return 0, nil, err
}
return decodeStartAuthSession(resp)
}
func encodeUnseal(sessionHandle, itemHandle tpmutil.Handle, password string) ([]byte, error) {
ha, err := tpmutil.Pack(itemHandle)
if err != nil {
return nil, err
}
auth, err := encodeAuthArea(AuthCommand{Session: sessionHandle, Attributes: AttrContinueSession, Auth: []byte(password)})
if err != nil {
return nil, err
}
return concat(ha, auth)
}
func decodeUnseal(in []byte) ([]byte, error) {
var paramSize uint32
var unsealed tpmutil.U16Bytes
if _, err := tpmutil.Unpack(in, ¶mSize, &unsealed); err != nil {
return nil, err
}
return unsealed, nil
}
// Unseal returns the data for a loaded sealed object.
func Unseal(rw io.ReadWriter, itemHandle tpmutil.Handle, password string) ([]byte, error) {
return UnsealWithSession(rw, HandlePasswordSession, itemHandle, password)
}
// UnsealWithSession returns the data for a loaded sealed object.
func UnsealWithSession(rw io.ReadWriter, sessionHandle, itemHandle tpmutil.Handle, password string) ([]byte, error) {
Cmd, err := encodeUnseal(sessionHandle, itemHandle, password)
if err != nil {
return nil, err
}
resp, err := runCommand(rw, TagSessions, CmdUnseal, tpmutil.RawBytes(Cmd))
if err != nil {
return nil, err
}
return decodeUnseal(resp)
}
func encodeQuote(signingHandle tpmutil.Handle, parentPassword, ownerPassword string, toQuote tpmutil.U16Bytes, sel PCRSelection, sigAlg Algorithm) ([]byte, error) {
ha, err := tpmutil.Pack(signingHandle)
if err != nil {
return nil, err
}
auth, err := encodeAuthArea(AuthCommand{Session: HandlePasswordSession, Attributes: AttrContinueSession, Auth: []byte(parentPassword)})
if err != nil {
return nil, err
}
params, err := tpmutil.Pack(toQuote, sigAlg)
if err != nil {
return nil, err
}
pcrs, err := encodeTPMLPCRSelection(sel)
if err != nil {
return nil, err
}
return concat(ha, auth, params, pcrs)
}
func decodeQuote(in []byte) ([]byte, []byte, error) {
buf := bytes.NewBuffer(in)
var paramSize uint32
if err := tpmutil.UnpackBuf(buf, ¶mSize); err != nil {
return nil, nil, err
}
buf.Truncate(int(paramSize))
var attest tpmutil.U16Bytes
if err := tpmutil.UnpackBuf(buf, &attest); err != nil {
return nil, nil, err
}
return attest, buf.Bytes(), nil
}
// Quote returns a quote of PCR values. A quote is a signature of the PCR
// values, created using a signing TPM key.
//
// Returns attestation data and the decoded signature.
func Quote(rw io.ReadWriter, signingHandle tpmutil.Handle, parentPassword, ownerPassword string, toQuote []byte, sel PCRSelection, sigAlg Algorithm) ([]byte, *Signature, error) {
attest, sigRaw, err := QuoteRaw(rw, signingHandle, parentPassword, ownerPassword, toQuote, sel, sigAlg)
if err != nil {
return nil, nil, err
}
sig, err := DecodeSignature(bytes.NewBuffer(sigRaw))
if err != nil {
return nil, nil, err
}
return attest, sig, nil
}
// QuoteRaw is very similar to Quote, except that it will return
// the raw signature in a byte array without decoding.
func QuoteRaw(rw io.ReadWriter, signingHandle tpmutil.Handle, parentPassword, ownerPassword string, toQuote []byte, sel PCRSelection, sigAlg Algorithm) ([]byte, []byte, error) {
Cmd, err := encodeQuote(signingHandle, parentPassword, ownerPassword, toQuote, sel, sigAlg)
if err != nil {
return nil, nil, err
}
resp, err := runCommand(rw, TagSessions, CmdQuote, tpmutil.RawBytes(Cmd))
if err != nil {
return nil, nil, err
}
return decodeQuote(resp)
}
func encodeActivateCredential(auth []AuthCommand, activeHandle tpmutil.Handle, keyHandle tpmutil.Handle, credBlob, secret tpmutil.U16Bytes) ([]byte, error) {
ha, err := tpmutil.Pack(activeHandle, keyHandle)
if err != nil {
return nil, err
}
a, err := encodeAuthArea(auth...)
if err != nil {
return nil, err
}
params, err := tpmutil.Pack(credBlob, secret)
if err != nil {
return nil, err
}
return concat(ha, a, params)
}
func decodeActivateCredential(in []byte) ([]byte, error) {
var paramSize uint32
var certInfo tpmutil.U16Bytes
if _, err := tpmutil.Unpack(in, ¶mSize, &certInfo); err != nil {
return nil, err
}
return certInfo, nil