Merge branch 'master' into renovate/github.com-go-webauthn-revoke-0.1.x

go.mod

@@ -6,15 +6,17 @@ require (
  github.com/fxamacker/cbor/v2 v2.4.0
  github.com/go-webauthn/revoke v0.1.4
  github.com/golang-jwt/jwt/v4 v4.4.2
+ github.com/google/go-tpm v0.3.3
  github.com/google/uuid v1.3.0
  github.com/mitchellh/mapstructure v1.5.0
  github.com/stretchr/testify v1.8.0
- golang.org/x/crypto d6f0a8c073c2
+ golang.org/x/crypto v0.0.0-20220817201139-bc19a97f63c8
 )
 
 require (
  github.com/davecgh/go-spew v1.1.1 // indirect
  github.com/pmezard/go-difflib v1.0.0 // indirect
  github.com/x448/float16 v0.8.4 // indirect
+ golang.org/x/sys v0.0.0-20210629170331-7dc0b73dc9fb // indirect
  gopkg.in/yaml.v3 v3.0.1 // indirect
 )

protocol/attestation_tpm.go

@@ -7,20 +7,17 @@ import (
  "encoding/asn1"
  "errors"
  "fmt"
- "math/big"
  "strings"
 
  "github.com/go-webauthn/webauthn/metadata"
  "github.com/go-webauthn/webauthn/protocol/webauthncose"
-
- "github.com/go-webauthn/webauthn/protocol/googletpm"
+ "github.com/google/go-tpm/tpm2"
 )
 
 var tpmAttestationKey = "tpm"
 
 func init() {
  RegisterAttestationFormat(tpmAttestationKey, verifyTPMFormat)
- googletpm.UseTPM20LengthPrefixSize()
 }
 
 func verifyTPMFormat(att AttestationObject, clientDataHash []byte) (string, []interface{}, error) {
@@ -74,27 +71,26 @@ func verifyTPMFormat(att AttestationObject, clientDataHash []byte) (string, []in
 
  // Verify that the public key specified by the parameters and unique fields of pubArea
  // is identical to the credentialPublicKey in the attestedCredentialData in authenticatorData.
- pubArea, err := googletpm.DecodePublic(pubAreaBytes)
+ pubArea, err := tpm2.DecodePublic(pubAreaBytes)
  if err != nil {
  return "", nil, ErrAttestationFormat.WithDetails("Unable to decode TPMT_PUBLIC in attestation statement")
  }
 
  key, err := webauthncose.ParsePublicKey(att.AuthData.AttData.CredentialPublicKey)
  if err != nil {
- return tpmAttestationKey, nil, err
+ return "", nil, err
  }
  switch key := key.(type) {
  case webauthncose.EC2PublicKeyData:
  if pubArea.ECCParameters.CurveID != key.TPMCurveID() ||
- pubArea.ECCParameters.Point.X.Cmp(new(big.Int).SetBytes(key.XCoord)) != 0 ||
- pubArea.ECCParameters.Point.Y.Cmp(new(big.Int).SetBytes(key.YCoord)) != 0 {
- return tpmAttestationKey, nil, ErrAttestationFormat.WithDetails("Mismatch between ECCParameters in pubArea and credentialPublicKey")
+ !bytes.Equal(pubArea.ECCParameters.Point.XRaw, key.XCoord) ||
+ !bytes.Equal(pubArea.ECCParameters.Point.YRaw, key.YCoord) {
+ return "", nil, ErrAttestationFormat.WithDetails("Mismatch between ECCParameters in pubArea and credentialPublicKey")
  }
  case webauthncose.RSAPublicKeyData:
- mod := new(big.Int).SetBytes(key.Modulus)
  exp := uint32(key.Exponent[0]) + uint32(key.Exponent[1])<<8 + uint32(key.Exponent[2])<<16
- if pubArea.RSAParameters.Modulus.Cmp(mod) != 0 ||
- pubArea.RSAParameters.Exponent != exp {
+ if !bytes.Equal(pubArea.RSAParameters.ModulusRaw, key.Modulus) ||
+ pubArea.RSAParameters.Exponent() != exp {
  return "", nil, ErrAttestationFormat.WithDetails("Mismatch between RSAParameters in pubArea and credentialPublicKey")
  }
  default:
@@ -105,34 +101,34 @@ func verifyTPMFormat(att AttestationObject, clientDataHash []byte) (string, []in
  attToBeSigned := append(att.RawAuthData, clientDataHash...)
 
  // Validate that certInfo is valid:
- certInfo, err := googletpm.DecodeAttestationData(certInfoBytes)
+ // 1/4 Verify that magic is set to TPM_GENERATED_VALUE, handled here
+ certInfo, err := tpm2.DecodeAttestationData(certInfoBytes)
  if err != nil {
- return tpmAttestationKey, nil, err
- }
- // 1/4 Verify that magic is set to TPM_GENERATED_VALUE.
- if certInfo.Magic != 0xff544347 {
- return "", nil, ErrAttestationFormat.WithDetails("Magic is not set to TPM_GENERATED_VALUE")
+ return "", nil, err
  }
+
  // 2/4 Verify that type is set to TPM_ST_ATTEST_CERTIFY.
- if certInfo.Type != googletpm.TagAttestCertify {
+ if certInfo.Type != tpm2.TagAttestCertify {
  return "", nil, ErrAttestationFormat.WithDetails("Type is not set to TPM_ST_ATTEST_CERTIFY")
  }
  // 3/4 Verify that extraData is set to the hash of attToBeSigned using the hash algorithm employed in "alg".
  f := webauthncose.HasherFromCOSEAlg(coseAlg)
  h := f()
  h.Write(attToBeSigned)
  if !bytes.Equal(certInfo.ExtraData, h.Sum(nil)) {
- return tpmAttestationKey, nil, ErrAttestationFormat.WithDetails("ExtraData is not set to hash of attToBeSigned")
+ return "", nil, ErrAttestationFormat.WithDetails("ExtraData is not set to hash of attToBeSigned")
  }
  // 4/4 Verify that attested contains a TPMS_CERTIFY_INFO structure as specified in
  // [TPMv2-Part2] section 10.12.3, whose name field contains a valid Name for pubArea,
  // as computed using the algorithm in the nameAlg field of pubArea
  // using the procedure specified in [TPMv2-Part1] section 16.
- f, err = certInfo.AttestedCertifyInfo.Name.Digest.Alg.HashConstructor()
- h = f()
- h.Write(pubAreaBytes)
- if !bytes.Equal(h.Sum(nil), certInfo.AttestedCertifyInfo.Name.Digest.Value) {
- return tpmAttestationKey, nil, ErrAttestationFormat.WithDetails("Hash value mismatch attested and pubArea")
+ matches, err := certInfo.AttestedCertifyInfo.Name.MatchesPublic(pubArea)
+ if err != nil {
+ return "", nil, err
+ }
+
+ if !matches {
+ return "", nil, ErrAttestationFormat.WithDetails("Hash value mismatch attested and pubArea")
  }
 
  // Note that the remaining fields in the "Standard Attestation Structure"
@@ -176,7 +172,7 @@ func verifyTPMFormat(att AttestationObject, clientDataHash []byte) (string, []in
  if ext.Id.Equal([]int{2, 5, 29, 17}) {
  manufacturer, model, version, err = parseSANExtension(ext.Value)
  if err != nil {
- return tpmAttestationKey, nil, err
+ return "", nil, err
  }
  }
  }
@@ -186,7 +182,7 @@ func verifyTPMFormat(att AttestationObject, clientDataHash []byte) (string, []in
  }
 
  if !isValidTPMManufacturer(manufacturer) {
- return tpmAttestationKey, nil, ErrAttestationFormat.WithDetails("Invalid TPM manufacturer")
+ return "", nil, ErrAttestationFormat.WithDetails("Invalid TPM manufacturer")
  }
 
  // 4/6 The Extended Key Usage extension MUST contain the "joint-iso-itu-t(2) internationalorganizations(23) 133 tcg-kp(8) tcg-kp-AIKCertificate(3)" OID.
@@ -202,7 +198,7 @@ func verifyTPMFormat(att AttestationObject, clientDataHash []byte) (string, []in
  }
  }
  if !ekuValid {
- return tpmAttestationKey, nil, ErrAttestationFormat.WithDetails("AIK certificate missing EKU")
+ return "", nil, ErrAttestationFormat.WithDetails("AIK certificate missing EKU")
  }
 
  // 5/6 The Basic Constraints extension MUST have the CA component set to false.
@@ -221,7 +217,7 @@ func verifyTPMFormat(att AttestationObject, clientDataHash []byte) (string, []in
  }
  }
  if constraints.IsCA {
- return tpmAttestationKey, nil, ErrAttestationFormat.WithDetails("AIK certificate basic constraints missing or CA is true")
+ return "", nil, ErrAttestationFormat.WithDetails("AIK certificate basic constraints missing or CA is true")
  }
  // 6/6 An Authority Information Access (AIA) extension with entry id-ad-ocsp and a CRL Distribution Point
  // extension [RFC5280] are both OPTIONAL as the status of many attestation certificates is available