package ocsp

import "golang.org/x/crypto/ocsp"

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.

Index ¶

Package Files ¶

ocsp.go

Constants ¶

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 status values that can be expressed in OCSP. See RFC 6960.

const (
    Unspecified          = iota
    KeyCompromise        = iota
    CACompromise         = iota
    AffiliationChanged   = iota
    Superseded           = iota
    CessationOfOperation = iota
    CertificateHold      = iota

    RemoveFromCRL      = iota
    PrivilegeWithdrawn = iota
    AACompromise       = iota
)

The enumerated reasons for revoking a certificate. See RFC 5280.

Variables ¶

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}
)

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.

func CreateRequest ¶

func CreateRequest(cert, issuer *x509.Certificate, opts *RequestOptions) ([]byte, error)

CreateRequest returns a DER-encoded, OCSP request for the status of cert. If opts is nil then sensible defaults are used.

func CreateResponse ¶

func CreateResponse(issuer, responderCert *x509.Certificate, template Response, priv crypto.Signer) ([]byte, error)

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 ResponderName field, and the certificate itself is provided alongside the OCSP response signature.

The issuer cert is used to puplate the IssuerNameHash and IssuerKeyHash fields. (SHA-1 is used for the hash function; this is not configurable.)

The template is used to populate the SerialNumber, RevocationStatus, RevokedAt, RevocationReason, ThisUpdate, and NextUpdate fields.

The ProducedAt date is automatically set to the current date, to the nearest minute.

type ParseError ¶

type ParseError string

ParseError results from an invalid OCSP response.

func (ParseError) Error ¶

func (p ParseError) Error() string

type Request ¶

type Request struct {
    HashAlgorithm  crypto.Hash
    IssuerNameHash []byte
    IssuerKeyHash  []byte
    SerialNumber   *big.Int
}

Request represents an OCSP request. See RFC 6960.

func ParseRequest ¶

func ParseRequest(bytes []byte) (*Request, error)

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.

type RequestOptions ¶

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
}

RequestOptions contains options for constructing OCSP requests.

type Response ¶

type Response struct {
    // 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

    // 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
}

Response represents an OCSP response containing a single SingleResponse. See RFC 6960.

func ParseResponse ¶

func ParseResponse(bytes []byte, issuer *x509.Certificate) (*Response, error)

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. Error responses will result in a ResponseError.

func (*Response) CheckSignatureFrom ¶

func (resp *Response) CheckSignatureFrom(issuer *x509.Certificate) error

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.

type ResponseError ¶

type ResponseError struct {
    Status ResponseStatus
}

ResponseError is an error that may be returned by ParseResponse to indicate that the response itself is an error, not just that its indicating that a certificate is revoked, unknown, etc.

func (ResponseError) Error ¶

func (r ResponseError) Error() string

type ResponseStatus ¶

type ResponseStatus int

ResponseStatus contains the result of an OCSP request. See https://tools.ietf.org/html/rfc6960#section-2.3

const (
    Success       ResponseStatus = 0
    Malformed     ResponseStatus = 1
    InternalError ResponseStatus = 2
    TryLater      ResponseStatus = 3
    // Status code four is ununsed in OCSP. See
    // https://tools.ietf.org/html/rfc6960#section-4.2.1
    SignatureRequired ResponseStatus = 5
    Unauthorized      ResponseStatus = 6
)

func (ResponseStatus) String ¶

func (r ResponseStatus) String() string