Vendor in containers/(storage,image, common, buildah)

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

1 files changed, 792 insertions, 0 deletions

diff --git a/vendor/golang.org/x/crypto/ocsp/ocsp.go b/vendor/golang.org/x/crypto/ocsp/ocsp.go
new file mode 100644
index 000000000..4269ed113
--- /dev/null
+++ b/vendor/golang.org/x/crypto/ocsp/ocsp.go
@@ -0,0 +1,792 @@
+// 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/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	_ "crypto/sha1"
+	_ "crypto/sha256"
+	_ "crypto/sha512"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"errors"
+	"fmt"
+	"math/big"
+	"strconv"
+	"time"
+)
+
+var idPKIXOCSPBasic = asn1.ObjectIdentifier([]int{1, 3, 6, 1, 5, 5, 7, 48, 1, 1})
+
+// ResponseStatus contains the result of an OCSP request. See
+// https://tools.ietf.org/html/rfc6960#section-2.3
+type ResponseStatus int
+
+const (
+	Success       ResponseStatus = 0
+	Malformed     ResponseStatus = 1
+	InternalError ResponseStatus = 2
+	TryLater      ResponseStatus = 3
+	// Status code four is unused in OCSP. See
+	// https://tools.ietf.org/html/rfc6960#section-4.2.1
+	SignatureRequired ResponseStatus = 5
+	Unauthorized      ResponseStatus = 6
+)
+
+func (r ResponseStatus) String() string {
+	switch r {
+	case Success:
+		return "success"
+	case Malformed:
+		return "malformed"
+	case InternalError:
+		return "internal error"
+	case TryLater:
+		return "try later"
+	case SignatureRequired:
+		return "signature required"
+	case Unauthorized:
+		return "unauthorized"
+	default:
+		return "unknown OCSP status: " + strconv.Itoa(int(r))
+	}
+}
+
+// ResponseError is an error that may be returned by ParseResponse to indicate
+// that the response itself is an error, not just that it's indicating that a
+// certificate is revoked, unknown, etc.
+type ResponseError struct {
+	Status ResponseStatus
+}
+
+func (r ResponseError) Error() string {
+	return "ocsp: error from server: " + r.Status.String()
+}
+
+// These are internal structures that reflect the ASN.1 structure of an OCSP
+// response. See RFC 2560, section 4.2.
+
+type certID struct {
+	HashAlgorithm pkix.AlgorithmIdentifier
+	NameHash      []byte
+	IssuerKeyHash []byte
+	SerialNumber  *big.Int
+}
+
+// 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,optional"`
+	RequestorName pkix.RDNSequence `asn1:"explicit,tag:1,optional"`
+	RequestList   []request
+}
+
+type request struct {
+	Cert certID
+}
+
+type responseASN1 struct {
+	Status   asn1.Enumerated
+	Response responseBytes `asn1:"explicit,tag:0,optional"`
+}
+
+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:0,explicit,tag:0"`
+	RawResponderID asn1.RawValue
+	ProducedAt     time.Time `asn1:"generalized"`
+	Responses      []singleResponse
+}
+
+type singleResponse struct {
+	CertID           certID
+	Good             asn1.Flag        `asn1:"tag:0,optional"`
+	Revoked          revokedInfo      `asn1:"tag:1,optional"`
+	Unknown          asn1.Flag        `asn1:"tag:2,optional"`
+	ThisUpdate       time.Time        `asn1:"generalized"`
+	NextUpdate       time.Time        `asn1:"generalized,explicit,tag:0,optional"`
+	SingleExtensions []pkix.Extension `asn1:"explicit,tag:1,optional"`
+}
+
+type revokedInfo struct {
+	RevocationTime time.Time       `asn1:"generalized"`
+	Reason         asn1.Enumerated `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, 3, 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}
+)
+
+var hashOIDs = map[crypto.Hash]asn1.ObjectIdentifier{
+	crypto.SHA1:   asn1.ObjectIdentifier([]int{1, 3, 14, 3, 2, 26}),
+	crypto.SHA256: asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 1}),
+	crypto.SHA384: asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 2}),
+	crypto.SHA512: asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 3}),
+}
+
+// TODO(rlb): This is also from crypto/x509, so same comment as AGL's below
+var signatureAlgorithmDetails = []struct {
+	algo       x509.SignatureAlgorithm
+	oid        asn1.ObjectIdentifier
+	pubKeyAlgo x509.PublicKeyAlgorithm
+	hash       crypto.Hash
+}{
+	{x509.MD2WithRSA, oidSignatureMD2WithRSA, x509.RSA, crypto.Hash(0) /* no value for MD2 */},
+	{x509.MD5WithRSA, oidSignatureMD5WithRSA, x509.RSA, crypto.MD5},
+	{x509.SHA1WithRSA, oidSignatureSHA1WithRSA, x509.RSA, crypto.SHA1},
+	{x509.SHA256WithRSA, oidSignatureSHA256WithRSA, x509.RSA, crypto.SHA256},
+	{x509.SHA384WithRSA, oidSignatureSHA384WithRSA, x509.RSA, crypto.SHA384},
+	{x509.SHA512WithRSA, oidSignatureSHA512WithRSA, x509.RSA, crypto.SHA512},
+	{x509.DSAWithSHA1, oidSignatureDSAWithSHA1, x509.DSA, crypto.SHA1},
+	{x509.DSAWithSHA256, oidSignatureDSAWithSHA256, x509.DSA, crypto.SHA256},
+	{x509.ECDSAWithSHA1, oidSignatureECDSAWithSHA1, x509.ECDSA, crypto.SHA1},
+	{x509.ECDSAWithSHA256, oidSignatureECDSAWithSHA256, x509.ECDSA, crypto.SHA256},
+	{x509.ECDSAWithSHA384, oidSignatureECDSAWithSHA384, x509.ECDSA, crypto.SHA384},
+	{x509.ECDSAWithSHA512, oidSignatureECDSAWithSHA512, x509.ECDSA, crypto.SHA512},
+}
+
+// TODO(rlb): This is also from crypto/x509, so same comment as AGL's below
+func signingParamsForPublicKey(pub interface{}, requestedSigAlgo x509.SignatureAlgorithm) (hashFunc crypto.Hash, sigAlgo pkix.AlgorithmIdentifier, err error) {
+	var pubType x509.PublicKeyAlgorithm
+
+	switch pub := pub.(type) {
+	case *rsa.PublicKey:
+		pubType = x509.RSA
+		hashFunc = crypto.SHA256
+		sigAlgo.Algorithm = oidSignatureSHA256WithRSA
+		sigAlgo.Parameters = asn1.RawValue{
+			Tag: 5,
+		}
+
+	case *ecdsa.PublicKey:
+		pubType = x509.ECDSA
+
+		switch pub.Curve {
+		case elliptic.P224(), elliptic.P256():
+			hashFunc = crypto.SHA256
+			sigAlgo.Algorithm = oidSignatureECDSAWithSHA256
+		case elliptic.P384():
+			hashFunc = crypto.SHA384
+			sigAlgo.Algorithm = oidSignatureECDSAWithSHA384
+		case elliptic.P521():
+			hashFunc = crypto.SHA512
+			sigAlgo.Algorithm = oidSignatureECDSAWithSHA512
+		default:
+			err = errors.New("x509: unknown elliptic curve")
+		}
+
+	default:
+		err = errors.New("x509: only RSA and ECDSA keys supported")
+	}
+
+	if err != nil {
+		return
+	}
+
+	if requestedSigAlgo == 0 {
+		return
+	}
+
+	found := false
+	for _, details := range signatureAlgorithmDetails {
+		if details.algo == requestedSigAlgo {
+			if details.pubKeyAlgo != pubType {
+				err = errors.New("x509: requested SignatureAlgorithm does not match private key type")
+				return
+			}
+			sigAlgo.Algorithm, hashFunc = details.oid, details.hash
+			if hashFunc == 0 {
+				err = errors.New("x509: cannot sign with hash function requested")
+				return
+			}
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		err = errors.New("x509: unknown SignatureAlgorithm")
+	}
+
+	return
+}
+
+// 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 {
+	for _, details := range signatureAlgorithmDetails {
+		if oid.Equal(details.oid) {
+			return details.algo
+		}
+	}
+	return x509.UnknownSignatureAlgorithm
+}
+
+// TODO(rlb): This is not taken from crypto/x509, but it's of the same general form.
+func getHashAlgorithmFromOID(target asn1.ObjectIdentifier) crypto.Hash {
+	for hash, oid := range hashOIDs {
+		if oid.Equal(target) {
+			return hash
+		}
+	}
+	return crypto.Hash(0)
+}
+
+func getOIDFromHashAlgorithm(target crypto.Hash) asn1.ObjectIdentifier {
+	for hash, oid := range hashOIDs {
+		if hash == target {
+			return oid
+		}
+	}
+	return nil
+}
+
+// This is the exposed reflection of the internal OCSP structures.
+
+// The status values that can be expressed in OCSP.  See RFC 6960.
+const (
+	// Good means that the certificate is valid.
+	Good = iota
+	// Revoked means that the certificate has been deliberately revoked.
+	Revoked
+	// Unknown means that the OCSP responder doesn't know about the certificate.
+	Unknown
+	// ServerFailed is unused and was never used (see
+	// https://go-review.googlesource.com/#/c/18944). ParseResponse will
+	// return a ResponseError when an error response is parsed.
+	ServerFailed
+)
+
+// The enumerated reasons for revoking a certificate.  See RFC 5280.
+const (
+	Unspecified          = 0
+	KeyCompromise        = 1
+	CACompromise         = 2
+	AffiliationChanged   = 3
+	Superseded           = 4
+	CessationOfOperation = 5
+	CertificateHold      = 6
+
+	RemoveFromCRL      = 8
+	PrivilegeWithdrawn = 9
+	AACompromise       = 10
+)
+
+// Request represents an OCSP request. See RFC 6960.
+type Request struct {
+	HashAlgorithm  crypto.Hash
+	IssuerNameHash []byte
+	IssuerKeyHash  []byte
+	SerialNumber   *big.Int
+}
+
+// Marshal marshals the OCSP request to ASN.1 DER encoded form.
+func (req *Request) Marshal() ([]byte, error) {
+	hashAlg := getOIDFromHashAlgorithm(req.HashAlgorithm)
+	if hashAlg == nil {
+		return nil, errors.New("Unknown hash algorithm")
+	}
+	return asn1.Marshal(ocspRequest{
+		tbsRequest{
+			Version: 0,
+			RequestList: []request{
+				{
+					Cert: certID{
+						pkix.AlgorithmIdentifier{
+							Algorithm:  hashAlg,
+							Parameters: asn1.RawValue{Tag: 5 /* ASN.1 NULL */},
+						},
+						req.IssuerNameHash,
+						req.IssuerKeyHash,
+						req.SerialNumber,
+					},
+				},
+			},
+		},
+	})
+}
+
+// Response represents an OCSP response containing a single SingleResponse. See
+// RFC 6960.
+type Response struct {
+	Raw []byte
+
+	// Status is one of {Good, Revoked, Unknown}
+	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
+
+	// IssuerHash is the hash used to compute the IssuerNameHash and IssuerKeyHash.
+	// Valid values are crypto.SHA1, crypto.SHA256, crypto.SHA384, and crypto.SHA512.
+	// If zero, the default is crypto.SHA1.
+	IssuerHash crypto.Hash
+
+	// RawResponderName optionally contains the DER-encoded subject of the
+	// responder certificate. Exactly one of RawResponderName and
+	// ResponderKeyHash is set.
+	RawResponderName []byte
+	// ResponderKeyHash optionally contains the SHA-1 hash of the
+	// responder's public key. Exactly one of RawResponderName and
+	// ResponderKeyHash is set.
+	ResponderKeyHash []byte
+
+	// Extensions contains raw X.509 extensions from the singleExtensions field
+	// of the OCSP response. When parsing certificates, this can be used to
+	// extract non-critical extensions that are not parsed by this package. When
+	// marshaling OCSP responses, the Extensions field is ignored, see
+	// ExtraExtensions.
+	Extensions []pkix.Extension
+
+	// ExtraExtensions contains extensions to be copied, raw, into any marshaled
+	// OCSP response (in the singleExtensions field). Values override any
+	// extensions that would otherwise be produced based on the other fields. The
+	// ExtraExtensions field is not populated when parsing certificates, see
+	// Extensions.
+	ExtraExtensions []pkix.Extension
+}
+
+// These are pre-serialized error responses for the various non-success codes
+// defined by OCSP. The Unauthorized code in particular can be used by an OCSP
+// responder that supports only pre-signed responses as a response to requests
+// for certificates with unknown status. See RFC 5019.
+var (
+	MalformedRequestErrorResponse = []byte{0x30, 0x03, 0x0A, 0x01, 0x01}
+	InternalErrorErrorResponse    = []byte{0x30, 0x03, 0x0A, 0x01, 0x02}
+	TryLaterErrorResponse         = []byte{0x30, 0x03, 0x0A, 0x01, 0x03}
+	SigRequredErrorResponse       = []byte{0x30, 0x03, 0x0A, 0x01, 0x05}
+	UnauthorizedErrorResponse     = []byte{0x30, 0x03, 0x0A, 0x01, 0x06}
+)
+
+// 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)
+}
+
+// ParseRequest parses an OCSP request in DER form. It only supports
+// requests for a single certificate. Signed requests are not supported.
+// If a request includes a signature, it will result in a ParseError.
+func ParseRequest(bytes []byte) (*Request, error) {
+	var req ocspRequest
+	rest, err := asn1.Unmarshal(bytes, &req)
+	if err != nil {
+		return nil, err
+	}
+	if len(rest) > 0 {
+		return nil, ParseError("trailing data in OCSP request")
+	}
+
+	if len(req.TBSRequest.RequestList) == 0 {
+		return nil, ParseError("OCSP request contains no request body")
+	}
+	innerRequest := req.TBSRequest.RequestList[0]
+
+	hashFunc := getHashAlgorithmFromOID(innerRequest.Cert.HashAlgorithm.Algorithm)
+	if hashFunc == crypto.Hash(0) {
+		return nil, ParseError("OCSP request uses unknown hash function")
+	}
+
+	return &Request{
+		HashAlgorithm:  hashFunc,
+		IssuerNameHash: innerRequest.Cert.NameHash,
+		IssuerKeyHash:  innerRequest.Cert.IssuerKeyHash,
+		SerialNumber:   innerRequest.Cert.SerialNumber,
+	}, nil
+}
+
+// ParseResponse parses an OCSP response in DER form. The response must contain
+// only one certificate status. To parse the status of a specific certificate
+// from a response which may contain multiple statuses, use ParseResponseForCert
+// instead.
+//
+// If the response contains an embedded certificate, then that certificate will
+// be used to verify the response signature. If the response contains an
+// embedded certificate and issuer is not nil, then issuer will be used to verify
+// the signature on the embedded certificate.
+//
+// If the response does not contain an embedded certificate and issuer is not
+// nil, then issuer will be used to verify the response signature.
+//
+// Invalid responses and parse failures will result in a ParseError.
+// Error responses will result in a ResponseError.
+func ParseResponse(bytes []byte, issuer *x509.Certificate) (*Response, error) {
+	return ParseResponseForCert(bytes, nil, issuer)
+}
+
+// ParseResponseForCert acts identically to ParseResponse, except it supports
+// parsing responses that contain multiple statuses. If the response contains
+// multiple statuses and cert is not nil, then ParseResponseForCert will return
+// the first status which contains a matching serial, otherwise it will return an
+// error. If cert is nil, then the first status in the response will be returned.
+func ParseResponseForCert(bytes []byte, cert, 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")
+	}
+
+	if status := ResponseStatus(resp.Status); status != Success {
+		return nil, ResponseError{status}
+	}
+
+	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(rest) > 0 {
+		return nil, ParseError("trailing data in OCSP response")
+	}
+
+	if n := len(basicResp.TBSResponseData.Responses); n == 0 || cert == nil && n > 1 {
+		return nil, ParseError("OCSP response contains bad number of responses")
+	}
+
+	var singleResp singleResponse
+	if cert == nil {
+		singleResp = basicResp.TBSResponseData.Responses[0]
+	} else {
+		match := false
+		for _, resp := range basicResp.TBSResponseData.Responses {
+			if cert.SerialNumber.Cmp(resp.CertID.SerialNumber) == 0 {
+				singleResp = resp
+				match = true
+				break
+			}
+		}
+		if !match {
+			return nil, ParseError("no response matching the supplied certificate")
+		}
+	}
+
+	ret := &Response{
+		Raw:                bytes,
+		TBSResponseData:    basicResp.TBSResponseData.Raw,
+		Signature:          basicResp.Signature.RightAlign(),
+		SignatureAlgorithm: getSignatureAlgorithmFromOID(basicResp.SignatureAlgorithm.Algorithm),
+		Extensions:         singleResp.SingleExtensions,
+		SerialNumber:       singleResp.CertID.SerialNumber,
+		ProducedAt:         basicResp.TBSResponseData.ProducedAt,
+		ThisUpdate:         singleResp.ThisUpdate,
+		NextUpdate:         singleResp.NextUpdate,
+	}
+
+	// Handle the ResponderID CHOICE tag. ResponderID can be flattened into
+	// TBSResponseData once https://go-review.googlesource.com/34503 has been
+	// released.
+	rawResponderID := basicResp.TBSResponseData.RawResponderID
+	switch rawResponderID.Tag {
+	case 1: // Name
+		var rdn pkix.RDNSequence
+		if rest, err := asn1.Unmarshal(rawResponderID.Bytes, &rdn); err != nil || len(rest) != 0 {
+			return nil, ParseError("invalid responder name")
+		}
+		ret.RawResponderName = rawResponderID.Bytes
+	case 2: // KeyHash
+		if rest, err := asn1.Unmarshal(rawResponderID.Bytes, &ret.ResponderKeyHash); err != nil || len(rest) != 0 {
+			return nil, ParseError("invalid responder key hash")
+		}
+	default:
+		return nil, ParseError("invalid responder id tag")
+	}
+
+	if len(basicResp.Certificates) > 0 {
+		// Responders should only send a single certificate (if they
+		// send any) that connects the responder's certificate to the
+		// original issuer. We accept responses with multiple
+		// certificates due to a number responders sending them[1], but
+		// ignore all but the first.
+		//
+		// [1] https://github.com/golang/go/issues/21527
+		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 signature on embedded certificate: " + err.Error())
+		}
+
+		if issuer != nil {
+			if err := issuer.CheckSignature(ret.Certificate.SignatureAlgorithm, ret.Certificate.RawTBSCertificate, ret.Certificate.Signature); err != nil {
+				return nil, ParseError("bad OCSP signature: " + err.Error())
+			}
+		}
+	} else if issuer != nil {
+		if err := ret.CheckSignatureFrom(issuer); err != nil {
+			return nil, ParseError("bad OCSP signature: " + err.Error())
+		}
+	}
+
+	for _, ext := range singleResp.SingleExtensions {
+		if ext.Critical {
+			return nil, ParseError("unsupported critical extension")
+		}
+	}
+
+	for h, oid := range hashOIDs {
+		if singleResp.CertID.HashAlgorithm.Algorithm.Equal(oid) {
+			ret.IssuerHash = h
+			break
+		}
+	}
+	if ret.IssuerHash == 0 {
+		return nil, ParseError("unsupported issuer hash algorithm")
+	}
+
+	switch {
+	case bool(singleResp.Good):
+		ret.Status = Good
+	case bool(singleResp.Unknown):
+		ret.Status = Unknown
+	default:
+		ret.Status = Revoked
+		ret.RevokedAt = singleResp.Revoked.RevocationTime
+		ret.RevocationReason = int(singleResp.Revoked.Reason)
+	}
+
+	return ret, nil
+}
+
+// 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
+	_, ok := hashOIDs[hashFunc]
+	if !ok {
+		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)
+
+	req := &Request{
+		HashAlgorithm:  hashFunc,
+		IssuerNameHash: issuerNameHash,
+		IssuerKeyHash:  issuerKeyHash,
+		SerialNumber:   cert.SerialNumber,
+	}
+	return req.Marshal()
+}
+
+// CreateResponse returns a DER-encoded OCSP response with the specified contents.
+// The fields in the response are populated as follows:
+//
+// The responder cert is used to populate the responder's name field, and the
+// certificate itself is provided alongside the OCSP response signature.
+//
+// The issuer cert is used to populate the IssuerNameHash and IssuerKeyHash fields.
+//
+// The template is used to populate the SerialNumber, Status, RevokedAt,
+// RevocationReason, ThisUpdate, and NextUpdate fields.
+//
+// If template.IssuerHash is not set, SHA1 will be used.
+//
+// The ProducedAt date is automatically set to the current date, to the nearest minute.
+func CreateResponse(issuer, responderCert *x509.Certificate, template Response, priv crypto.Signer) ([]byte, error) {
+	var publicKeyInfo struct {
+		Algorithm pkix.AlgorithmIdentifier
+		PublicKey asn1.BitString
+	}
+	if _, err := asn1.Unmarshal(issuer.RawSubjectPublicKeyInfo, &publicKeyInfo); err != nil {
+		return nil, err
+	}
+
+	if template.IssuerHash == 0 {
+		template.IssuerHash = crypto.SHA1
+	}
+	hashOID := getOIDFromHashAlgorithm(template.IssuerHash)
+	if hashOID == nil {
+		return nil, errors.New("unsupported issuer hash algorithm")
+	}
+
+	if !template.IssuerHash.Available() {
+		return nil, fmt.Errorf("issuer hash algorithm %v not linked into binary", template.IssuerHash)
+	}
+	h := template.IssuerHash.New()
+	h.Write(publicKeyInfo.PublicKey.RightAlign())
+	issuerKeyHash := h.Sum(nil)
+
+	h.Reset()
+	h.Write(issuer.RawSubject)
+	issuerNameHash := h.Sum(nil)
+
+	innerResponse := singleResponse{
+		CertID: certID{
+			HashAlgorithm: pkix.AlgorithmIdentifier{
+				Algorithm:  hashOID,
+				Parameters: asn1.RawValue{Tag: 5 /* ASN.1 NULL */},
+			},
+			NameHash:      issuerNameHash,
+			IssuerKeyHash: issuerKeyHash,
+			SerialNumber:  template.SerialNumber,
+		},
+		ThisUpdate:       template.ThisUpdate.UTC(),
+		NextUpdate:       template.NextUpdate.UTC(),
+		SingleExtensions: template.ExtraExtensions,
+	}
+
+	switch template.Status {
+	case Good:
+		innerResponse.Good = true
+	case Unknown:
+		innerResponse.Unknown = true
+	case Revoked:
+		innerResponse.Revoked = revokedInfo{
+			RevocationTime: template.RevokedAt.UTC(),
+			Reason:         asn1.Enumerated(template.RevocationReason),
+		}
+	}
+
+	rawResponderID := asn1.RawValue{
+		Class:      2, // context-specific
+		Tag:        1, // Name (explicit tag)
+		IsCompound: true,
+		Bytes:      responderCert.RawSubject,
+	}
+	tbsResponseData := responseData{
+		Version:        0,
+		RawResponderID: rawResponderID,
+		ProducedAt:     time.Now().Truncate(time.Minute).UTC(),
+		Responses:      []singleResponse{innerResponse},
+	}
+
+	tbsResponseDataDER, err := asn1.Marshal(tbsResponseData)
+	if err != nil {
+		return nil, err
+	}
+
+	hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(priv.Public(), template.SignatureAlgorithm)
+	if err != nil {
+		return nil, err
+	}
+
+	responseHash := hashFunc.New()
+	responseHash.Write(tbsResponseDataDER)
+	signature, err := priv.Sign(rand.Reader, responseHash.Sum(nil), hashFunc)
+	if err != nil {
+		return nil, err
+	}
+
+	response := basicResponse{
+		TBSResponseData:    tbsResponseData,
+		SignatureAlgorithm: signatureAlgorithm,
+		Signature: asn1.BitString{
+			Bytes:     signature,
+			BitLength: 8 * len(signature),
+		},
+	}
+	if template.Certificate != nil {
+		response.Certificates = []asn1.RawValue{
+			{FullBytes: template.Certificate.Raw},
+		}
+	}
+	responseDER, err := asn1.Marshal(response)
+	if err != nil {
+		return nil, err
+	}
+
+	return asn1.Marshal(responseASN1{
+		Status: asn1.Enumerated(Success),
+		Response: responseBytes{
+			ResponseType: idPKIXOCSPBasic,
+			Response:     responseDER,
+		},
+	})
+}