Vendor main dependencies.

vendor/golang.org/x/crypto/ocsp/ocsp.go

@@ -0,0 +1,347 @@
+// Copyright 2013 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 ocsp parses OCSP responses as specified in RFC 2560. OCSP responses
+// are signed messages attesting to the validity of a certificate for a small
+// period of time. This is used to manage revocation for X.509 certificates.
+package ocsp // import "golang.org/x/crypto/ocsp"
+
+import (
+	"crypto"
+	_ "crypto/sha1"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"math/big"
+	"time"
+)
+
+var idPKIXOCSPBasic = asn1.ObjectIdentifier([]int{1, 3, 6, 1, 5, 5, 7, 48, 1, 1})
+
+// These are internal structures that reflect the ASN.1 structure of an OCSP
+// response. See RFC 2560, section 4.2.
+
+const (
+	ocspSuccess       = 0
+	ocspMalformed     = 1
+	ocspInternalError = 2
+	ocspTryLater      = 3
+	ocspSigRequired   = 4
+	ocspUnauthorized  = 5
+)
+
+type certID struct {
+	HashAlgorithm pkix.AlgorithmIdentifier
+	NameHash      []byte
+	IssuerKeyHash []byte
+	SerialNumber  *big.Int
+}
+
+type responseASN1 struct {
+	Status   asn1.Enumerated
+	Response responseBytes `asn1:"explicit,tag:0"`
+}
+
+type responseBytes struct {
+	ResponseType asn1.ObjectIdentifier
+	Response     []byte
+}
+
+type basicResponse struct {
+	TBSResponseData    responseData
+	SignatureAlgorithm pkix.AlgorithmIdentifier
+	Signature          asn1.BitString
+	Certificates       []asn1.RawValue `asn1:"explicit,tag:0,optional"`
+}
+
+type responseData struct {
+	Raw           asn1.RawContent
+	Version       int              `asn1:"optional,default:1,explicit,tag:0"`
+	RequestorName pkix.RDNSequence `asn1:"optional,explicit,tag:1"`
+	KeyHash       []byte           `asn1:"optional,explicit,tag:2"`
+	ProducedAt    time.Time
+	Responses     []singleResponse
+}
+
+type singleResponse struct {
+	CertID     certID
+	Good       asn1.Flag   `asn1:"explicit,tag:0,optional"`
+	Revoked    revokedInfo `asn1:"explicit,tag:1,optional"`
+	Unknown    asn1.Flag   `asn1:"explicit,tag:2,optional"`
+	ThisUpdate time.Time
+	NextUpdate time.Time `asn1:"explicit,tag:0,optional"`
+}
+
+type revokedInfo struct {
+	RevocationTime time.Time
+	Reason         int `asn1:"explicit,tag:0,optional"`
+}
+
+var (
+	oidSignatureMD2WithRSA      = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 2}
+	oidSignatureMD5WithRSA      = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 4}
+	oidSignatureSHA1WithRSA     = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 5}
+	oidSignatureSHA256WithRSA   = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 11}
+	oidSignatureSHA384WithRSA   = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 12}
+	oidSignatureSHA512WithRSA   = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 13}
+	oidSignatureDSAWithSHA1     = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 3}
+	oidSignatureDSAWithSHA256   = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 4, 3, 2}
+	oidSignatureECDSAWithSHA1   = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 1}
+	oidSignatureECDSAWithSHA256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 2}
+	oidSignatureECDSAWithSHA384 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 3}
+	oidSignatureECDSAWithSHA512 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 4}
+)
+
+// TODO(agl): this is taken from crypto/x509 and so should probably be exported
+// from crypto/x509 or crypto/x509/pkix.
+func getSignatureAlgorithmFromOID(oid asn1.ObjectIdentifier) x509.SignatureAlgorithm {
+	switch {
+	case oid.Equal(oidSignatureMD2WithRSA):
+		return x509.MD2WithRSA
+	case oid.Equal(oidSignatureMD5WithRSA):
+		return x509.MD5WithRSA
+	case oid.Equal(oidSignatureSHA1WithRSA):
+		return x509.SHA1WithRSA
+	case oid.Equal(oidSignatureSHA256WithRSA):
+		return x509.SHA256WithRSA
+	case oid.Equal(oidSignatureSHA384WithRSA):
+		return x509.SHA384WithRSA
+	case oid.Equal(oidSignatureSHA512WithRSA):
+		return x509.SHA512WithRSA
+	case oid.Equal(oidSignatureDSAWithSHA1):
+		return x509.DSAWithSHA1
+	case oid.Equal(oidSignatureDSAWithSHA256):
+		return x509.DSAWithSHA256
+	case oid.Equal(oidSignatureECDSAWithSHA1):
+		return x509.ECDSAWithSHA1
+	case oid.Equal(oidSignatureECDSAWithSHA256):
+		return x509.ECDSAWithSHA256
+	case oid.Equal(oidSignatureECDSAWithSHA384):
+		return x509.ECDSAWithSHA384
+	case oid.Equal(oidSignatureECDSAWithSHA512):
+		return x509.ECDSAWithSHA512
+	}
+	return x509.UnknownSignatureAlgorithm
+}
+
+// This is the exposed reflection of the internal OCSP structures.
+
+const (
+	// Good means that the certificate is valid.
+	Good = iota
+	// Revoked means that the certificate has been deliberately revoked.
+	Revoked = iota
+	// Unknown means that the OCSP responder doesn't know about the certificate.
+	Unknown = iota
+	// ServerFailed means that the OCSP responder failed to process the request.
+	ServerFailed = iota
+)
+
+// Response represents an OCSP response. See RFC 2560.
+type Response struct {
+	// Status is one of {Good, Revoked, Unknown, ServerFailed}
+	Status                                        int
+	SerialNumber                                  *big.Int
+	ProducedAt, ThisUpdate, NextUpdate, RevokedAt time.Time
+	RevocationReason                              int
+	Certificate                                   *x509.Certificate
+	// TBSResponseData contains the raw bytes of the signed response. If
+	// Certificate is nil then this can be used to verify Signature.
+	TBSResponseData    []byte
+	Signature          []byte
+	SignatureAlgorithm x509.SignatureAlgorithm
+}
+
+// CheckSignatureFrom checks that the signature in resp is a valid signature
+// from issuer. This should only be used if resp.Certificate is nil. Otherwise,
+// the OCSP response contained an intermediate certificate that created the
+// signature. That signature is checked by ParseResponse and only
+// resp.Certificate remains to be validated.
+func (resp *Response) CheckSignatureFrom(issuer *x509.Certificate) error {
+	return issuer.CheckSignature(resp.SignatureAlgorithm, resp.TBSResponseData, resp.Signature)
+}
+
+// ParseError results from an invalid OCSP response.
+type ParseError string
+
+func (p ParseError) Error() string {
+	return string(p)
+}
+
+// ParseResponse parses an OCSP response in DER form. It only supports
+// responses for a single certificate. If the response contains a certificate
+// then the signature over the response is checked. If issuer is not nil then
+// it will be used to validate the signature or embedded certificate. Invalid
+// signatures or parse failures will result in a ParseError.
+func ParseResponse(bytes []byte, issuer *x509.Certificate) (*Response, error) {
+	var resp responseASN1
+	rest, err := asn1.Unmarshal(bytes, &resp)
+	if err != nil {
+		return nil, err
+	}
+	if len(rest) > 0 {
+		return nil, ParseError("trailing data in OCSP response")
+	}
+
+	ret := new(Response)
+	if resp.Status != ocspSuccess {
+		ret.Status = ServerFailed
+		return ret, nil
+	}
+
+	if !resp.Response.ResponseType.Equal(idPKIXOCSPBasic) {
+		return nil, ParseError("bad OCSP response type")
+	}
+
+	var basicResp basicResponse
+	rest, err = asn1.Unmarshal(resp.Response.Response, &basicResp)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(basicResp.Certificates) > 1 {
+		return nil, ParseError("OCSP response contains bad number of certificates")
+	}
+
+	if len(basicResp.TBSResponseData.Responses) != 1 {
+		return nil, ParseError("OCSP response contains bad number of responses")
+	}
+
+	ret.TBSResponseData = basicResp.TBSResponseData.Raw
+	ret.Signature = basicResp.Signature.RightAlign()
+	ret.SignatureAlgorithm = getSignatureAlgorithmFromOID(basicResp.SignatureAlgorithm.Algorithm)
+
+	if len(basicResp.Certificates) > 0 {
+		ret.Certificate, err = x509.ParseCertificate(basicResp.Certificates[0].FullBytes)
+		if err != nil {
+			return nil, err
+		}
+
+		if err := ret.CheckSignatureFrom(ret.Certificate); err != nil {
+			return nil, ParseError("bad OCSP signature")
+		}
+
+		if issuer != nil {
+			if err := issuer.CheckSignature(ret.Certificate.SignatureAlgorithm, ret.Certificate.RawTBSCertificate, ret.Certificate.Signature); err != nil {
+				return nil, ParseError("bad signature on embedded certificate")
+			}
+		}
+	} else if issuer != nil {
+		if err := ret.CheckSignatureFrom(issuer); err != nil {
+			return nil, ParseError("bad OCSP signature")
+		}
+	}
+
+	r := basicResp.TBSResponseData.Responses[0]
+
+	ret.SerialNumber = r.CertID.SerialNumber
+
+	switch {
+	case bool(r.Good):
+		ret.Status = Good
+	case bool(r.Unknown):
+		ret.Status = Unknown
+	default:
+		ret.Status = Revoked
+		ret.RevokedAt = r.Revoked.RevocationTime
+		ret.RevocationReason = r.Revoked.Reason
+	}
+
+	ret.ProducedAt = basicResp.TBSResponseData.ProducedAt
+	ret.ThisUpdate = r.ThisUpdate
+	ret.NextUpdate = r.NextUpdate
+
+	return ret, nil
+}
+
+// https://tools.ietf.org/html/rfc2560#section-4.1.1
+type ocspRequest struct {
+	TBSRequest tbsRequest
+}
+
+type tbsRequest struct {
+	Version     int `asn1:"explicit,tag:0,default:0"`
+	RequestList []request
+}
+
+type request struct {
+	Cert certID
+}
+
+// RequestOptions contains options for constructing OCSP requests.
+type RequestOptions struct {
+	// Hash contains the hash function that should be used when
+	// constructing the OCSP request. If zero, SHA-1 will be used.
+	Hash crypto.Hash
+}
+
+func (opts *RequestOptions) hash() crypto.Hash {
+	if opts == nil || opts.Hash == 0 {
+		// SHA-1 is nearly universally used in OCSP.
+		return crypto.SHA1
+	}
+	return opts.Hash
+}
+
+// CreateRequest returns a DER-encoded, OCSP request for the status of cert. If
+// opts is nil then sensible defaults are used.
+func CreateRequest(cert, issuer *x509.Certificate, opts *RequestOptions) ([]byte, error) {
+	hashFunc := opts.hash()
+
+	// OCSP seems to be the only place where these raw hash identifiers are
+	// used. I took the following from
+	// http://msdn.microsoft.com/en-us/library/ff635603.aspx
+	var hashOID asn1.ObjectIdentifier
+	switch hashFunc {
+	case crypto.SHA1:
+		hashOID = asn1.ObjectIdentifier([]int{1, 3, 14, 3, 2, 26})
+	case crypto.SHA256:
+		hashOID = asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 1})
+	case crypto.SHA384:
+		hashOID = asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 2})
+	case crypto.SHA512:
+		hashOID = asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 3})
+	default:
+		return nil, x509.ErrUnsupportedAlgorithm
+	}
+
+	if !hashFunc.Available() {
+		return nil, x509.ErrUnsupportedAlgorithm
+	}
+	h := opts.hash().New()
+
+	var publicKeyInfo struct {
+		Algorithm pkix.AlgorithmIdentifier
+		PublicKey asn1.BitString
+	}
+	if _, err := asn1.Unmarshal(issuer.RawSubjectPublicKeyInfo, &publicKeyInfo); err != nil {
+		return nil, err
+	}
+
+	h.Write(publicKeyInfo.PublicKey.RightAlign())
+	issuerKeyHash := h.Sum(nil)
+
+	h.Reset()
+	h.Write(issuer.RawSubject)
+	issuerNameHash := h.Sum(nil)
+
+	return asn1.Marshal(ocspRequest{
+		tbsRequest{
+			Version: 0,
+			RequestList: []request{
+				{
+					Cert: certID{
+						pkix.AlgorithmIdentifier{
+							Algorithm:  hashOID,
+							Parameters: asn1.RawValue{Tag: 5 /* ASN.1 NULL */},
+						},
+						issuerNameHash,
+						issuerKeyHash,
+						cert.SerialNumber,
+					},
+				},
+			},
+		},
+	})
+}