package x509

Import Path
	crypto/x509 (on golang.org and go.dev)

Dependency Relation
	imports 37 packages, and imported by 2 packages


Involved Source Files

	      cert_pool.go
	      pem_decrypt.go
	      pkcs1.go
	      pkcs8.go
	      root.go
	      root_linux.go
	      root_unix.go
	      sec1.go
	      verify.go
	
		Package x509 parses X.509-encoded keys and certificates.


Code Examples

	
		package main
		
		import (
			"crypto/x509"
			"encoding/pem"
		)
		
		func main() {
			// Verifying with a custom list of root certificates.
		
			const rootPEM = `
		-----BEGIN CERTIFICATE-----
		MIIEBDCCAuygAwIBAgIDAjppMA0GCSqGSIb3DQEBBQUAMEIxCzAJBgNVBAYTAlVT
		MRYwFAYDVQQKEw1HZW9UcnVzdCBJbmMuMRswGQYDVQQDExJHZW9UcnVzdCBHbG9i
		YWwgQ0EwHhcNMTMwNDA1MTUxNTU1WhcNMTUwNDA0MTUxNTU1WjBJMQswCQYDVQQG
		EwJVUzETMBEGA1UEChMKR29vZ2xlIEluYzElMCMGA1UEAxMcR29vZ2xlIEludGVy
		bmV0IEF1dGhvcml0eSBHMjCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEB
		AJwqBHdc2FCROgajguDYUEi8iT/xGXAaiEZ+4I/F8YnOIe5a/mENtzJEiaB0C1NP
		VaTOgmKV7utZX8bhBYASxF6UP7xbSDj0U/ck5vuR6RXEz/RTDfRK/J9U3n2+oGtv
		h8DQUB8oMANA2ghzUWx//zo8pzcGjr1LEQTrfSTe5vn8MXH7lNVg8y5Kr0LSy+rE
		ahqyzFPdFUuLH8gZYR/Nnag+YyuENWllhMgZxUYi+FOVvuOAShDGKuy6lyARxzmZ
		EASg8GF6lSWMTlJ14rbtCMoU/M4iarNOz0YDl5cDfsCx3nuvRTPPuj5xt970JSXC
		DTWJnZ37DhF5iR43xa+OcmkCAwEAAaOB+zCB+DAfBgNVHSMEGDAWgBTAephojYn7
		qwVkDBF9qn1luMrMTjAdBgNVHQ4EFgQUSt0GFhu89mi1dvWBtrtiGrpagS8wEgYD
		VR0TAQH/BAgwBgEB/wIBADAOBgNVHQ8BAf8EBAMCAQYwOgYDVR0fBDMwMTAvoC2g
		K4YpaHR0cDovL2NybC5nZW90cnVzdC5jb20vY3Jscy9ndGdsb2JhbC5jcmwwPQYI
		KwYBBQUHAQEEMTAvMC0GCCsGAQUFBzABhiFodHRwOi8vZ3RnbG9iYWwtb2NzcC5n
		ZW90cnVzdC5jb20wFwYDVR0gBBAwDjAMBgorBgEEAdZ5AgUBMA0GCSqGSIb3DQEB
		BQUAA4IBAQA21waAESetKhSbOHezI6B1WLuxfoNCunLaHtiONgaX4PCVOzf9G0JY
		/iLIa704XtE7JW4S615ndkZAkNoUyHgN7ZVm2o6Gb4ChulYylYbc3GrKBIxbf/a/
		zG+FA1jDaFETzf3I93k9mTXwVqO94FntT0QJo544evZG0R0SnU++0ED8Vf4GXjza
		HFa9llF7b1cq26KqltyMdMKVvvBulRP/F/A8rLIQjcxz++iPAsbw+zOzlTvjwsto
		WHPbqCRiOwY1nQ2pM714A5AuTHhdUDqB1O6gyHA43LL5Z/qHQF1hwFGPa4NrzQU6
		yuGnBXj8ytqU0CwIPX4WecigUCAkVDNx
		-----END CERTIFICATE-----`
		
			const certPEM = `
		-----BEGIN CERTIFICATE-----
		MIIDujCCAqKgAwIBAgIIE31FZVaPXTUwDQYJKoZIhvcNAQEFBQAwSTELMAkGA1UE
		BhMCVVMxEzARBgNVBAoTCkdvb2dsZSBJbmMxJTAjBgNVBAMTHEdvb2dsZSBJbnRl
		cm5ldCBBdXRob3JpdHkgRzIwHhcNMTQwMTI5MTMyNzQzWhcNMTQwNTI5MDAwMDAw
		WjBpMQswCQYDVQQGEwJVUzETMBEGA1UECAwKQ2FsaWZvcm5pYTEWMBQGA1UEBwwN
		TW91bnRhaW4gVmlldzETMBEGA1UECgwKR29vZ2xlIEluYzEYMBYGA1UEAwwPbWFp
		bC5nb29nbGUuY29tMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEfRrObuSW5T7q
		5CnSEqefEmtH4CCv6+5EckuriNr1CjfVvqzwfAhopXkLrq45EQm8vkmf7W96XJhC
		7ZM0dYi1/qOCAU8wggFLMB0GA1UdJQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjAa
		BgNVHREEEzARgg9tYWlsLmdvb2dsZS5jb20wCwYDVR0PBAQDAgeAMGgGCCsGAQUF
		BwEBBFwwWjArBggrBgEFBQcwAoYfaHR0cDovL3BraS5nb29nbGUuY29tL0dJQUcy
		LmNydDArBggrBgEFBQcwAYYfaHR0cDovL2NsaWVudHMxLmdvb2dsZS5jb20vb2Nz
		cDAdBgNVHQ4EFgQUiJxtimAuTfwb+aUtBn5UYKreKvMwDAYDVR0TAQH/BAIwADAf
		BgNVHSMEGDAWgBRK3QYWG7z2aLV29YG2u2IaulqBLzAXBgNVHSAEEDAOMAwGCisG
		AQQB1nkCBQEwMAYDVR0fBCkwJzAloCOgIYYfaHR0cDovL3BraS5nb29nbGUuY29t
		L0dJQUcyLmNybDANBgkqhkiG9w0BAQUFAAOCAQEAH6RYHxHdcGpMpFE3oxDoFnP+
		gtuBCHan2yE2GRbJ2Cw8Lw0MmuKqHlf9RSeYfd3BXeKkj1qO6TVKwCh+0HdZk283
		TZZyzmEOyclm3UGFYe82P/iDFt+CeQ3NpmBg+GoaVCuWAARJN/KfglbLyyYygcQq
		0SgeDh8dRKUiaW3HQSoYvTvdTuqzwK4CXsr3b5/dAOY8uMuG/IAR3FgwTbZ1dtoW
		RvOTa8hYiU6A475WuZKyEHcwnGYe57u2I2KbMgcKjPniocj4QzgYsVAVKW3IwaOh
		yE+vPxsiUkvQHdO2fojCkY8jg70jxM+gu59tPDNbw3Uh/2Ij310FgTHsnGQMyA==
		-----END CERTIFICATE-----`
		
			// First, create the set of root certificates. For this example we only
			// have one. It's also possible to omit this in order to use the
			// default root set of the current operating system.
			roots := x509.NewCertPool()
			ok := roots.AppendCertsFromPEM([]byte(rootPEM))
			if !ok {
				panic("failed to parse root certificate")
			}
		
			block, _ := pem.Decode([]byte(certPEM))
			if block == nil {
				panic("failed to parse certificate PEM")
			}
			cert, err := x509.ParseCertificate(block.Bytes)
			if err != nil {
				panic("failed to parse certificate: " + err.Error())
			}
		
			opts := x509.VerifyOptions{
				DNSName: "mail.google.com",
				Roots:   roots,
			}
		
			if _, err := cert.Verify(opts); err != nil {
				panic("failed to verify certificate: " + err.Error())
			}
		}


	
		package main
		
		import (
			"crypto/dsa"
			"crypto/ecdsa"
			"crypto/ed25519"
			"crypto/rsa"
			"crypto/x509"
			"encoding/pem"
			"fmt"
		)
		
		func main() {
			const pubPEM = `
		-----BEGIN PUBLIC KEY-----
		MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAlRuRnThUjU8/prwYxbty
		WPT9pURI3lbsKMiB6Fn/VHOKE13p4D8xgOCADpdRagdT6n4etr9atzDKUSvpMtR3
		CP5noNc97WiNCggBjVWhs7szEe8ugyqF23XwpHQ6uV1LKH50m92MbOWfCtjU9p/x
		qhNpQQ1AZhqNy5Gevap5k8XzRmjSldNAFZMY7Yv3Gi+nyCwGwpVtBUwhuLzgNFK/
		yDtw2WcWmUU7NuC8Q6MWvPebxVtCfVp/iQU6q60yyt6aGOBkhAX0LpKAEhKidixY
		nP9PNVBvxgu3XZ4P36gZV6+ummKdBVnc3NqwBLu5+CcdRdusmHPHd5pHf4/38Z3/
		6qU2a/fPvWzceVTEgZ47QjFMTCTmCwNt29cvi7zZeQzjtwQgn4ipN9NibRH/Ax/q
		TbIzHfrJ1xa2RteWSdFjwtxi9C20HUkjXSeI4YlzQMH0fPX6KCE7aVePTOnB69I/
		a9/q96DiXZajwlpq3wFctrs1oXqBp5DVrCIj8hU2wNgB7LtQ1mCtsYz//heai0K9
		PhE4X6hiE0YmeAZjR0uHl8M/5aW9xCoJ72+12kKpWAa0SFRWLy6FejNYCYpkupVJ
		yecLk/4L1W0l6jQQZnWErXZYe0PNFcmwGXy1Rep83kfBRNKRy5tvocalLlwXLdUk
		AIU+2GKjyT3iMuzZxxFxPFMCAwEAAQ==
		-----END PUBLIC KEY-----`
		
			block, _ := pem.Decode([]byte(pubPEM))
			if block == nil {
				panic("failed to parse PEM block containing the public key")
			}
		
			pub, err := x509.ParsePKIXPublicKey(block.Bytes)
			if err != nil {
				panic("failed to parse DER encoded public key: " + err.Error())
			}
		
			switch pub := pub.(type) {
			case *rsa.PublicKey:
				fmt.Println("pub is of type RSA:", pub)
			case *dsa.PublicKey:
				fmt.Println("pub is of type DSA:", pub)
			case *ecdsa.PublicKey:
				fmt.Println("pub is of type ECDSA:", pub)
			case ed25519.PublicKey:
				fmt.Println("pub is of type Ed25519:", pub)
			default:
				panic("unknown type of public key")
			}
		}




Package-Level Type Names (total 42, in which 18 are exported)


	/* sort exporteds by:  |  */
	
		A Certificate represents an X.509 certificate.

		
			AuthorityKeyId []byte
			
				BasicConstraintsValid indicates whether IsCA, MaxPathLen,
				and MaxPathLenZero are valid.

			
				CRL Distribution Points

			
				Subject Alternate Name values. (Note that these values may not be valid
				if invalid values were contained within a parsed certificate. For
				example, an element of DNSNames may not be a valid DNS domain name.)

			EmailAddresses []string
			ExcludedDNSDomains []string
			ExcludedEmailAddresses []string
			ExcludedIPRanges []*net.IPNet
			ExcludedURIDomains []string
			
				// Sequence of extended key usages.

			
				Extensions contains raw X.509 extensions. When parsing certificates,
				this can be used to extract non-critical extensions that are not
				parsed by this package. When marshaling certificates, the Extensions
				field is ignored, see ExtraExtensions.

			
				ExtraExtensions contains extensions to be copied, raw, into any
				marshaled certificates. 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.

			IPAddresses []net.IP
			IsCA bool
			Issuer pkix.Name
			IssuingCertificateURL []string
			KeyUsage KeyUsage
			
				MaxPathLen and MaxPathLenZero indicate the presence and
				value of the BasicConstraints' "pathLenConstraint".

				When parsing a certificate, a positive non-zero MaxPathLen
				means that the field was specified, -1 means it was unset,
				and MaxPathLenZero being true mean that the field was
				explicitly set to zero. The case of MaxPathLen==0 with MaxPathLenZero==false
				should be treated equivalent to -1 (unset).

				When generating a certificate, an unset pathLenConstraint
				can be requested with either MaxPathLen == -1 or using the
				zero value for both MaxPathLen and MaxPathLenZero.

			
				MaxPathLenZero indicates that BasicConstraintsValid==true
				and MaxPathLen==0 should be interpreted as an actual
				maximum path length of zero. Otherwise, that combination is
				interpreted as MaxPathLen not being set.

			
				// Validity bounds.

			
				// Validity bounds.

			
				RFC 5280, 4.2.2.1 (Authority Information Access)

			PermittedDNSDomains []string
			
				Name constraints
				// if true then the name constraints are marked critical.

			PermittedEmailAddresses []string
			PermittedIPRanges []*net.IPNet
			PermittedURIDomains []string
			PolicyIdentifiers []asn1.ObjectIdentifier
			PublicKey interface{}
			PublicKeyAlgorithm PublicKeyAlgorithm
			
				// Complete ASN.1 DER content (certificate, signature algorithm and signature).

			
				// DER encoded Issuer

			
				// DER encoded Subject

			
				// DER encoded SubjectPublicKeyInfo.

			
				// Certificate part of raw ASN.1 DER content.

			SerialNumber *big.Int
			Signature []byte
			SignatureAlgorithm SignatureAlgorithm
			Subject pkix.Name
			SubjectKeyId []byte
			URIs []*url.URL
			
				UnhandledCriticalExtensions contains a list of extension IDs that
				were not (fully) processed when parsing. Verify will fail if this
				slice is non-empty, unless verification is delegated to an OS
				library which understands all the critical extensions.

				Users can access these extensions using Extensions and can remove
				elements from this slice if they believe that they have been
				handled.

			
				// Encountered extended key usages unknown to this package.

			Version int
		
			
				CheckCRLSignature checks that the signature in crl is from c.

			
				CheckSignature verifies that signature is a valid signature over signed from
				c's public key.

			
				CheckSignatureFrom verifies that the signature on c is a valid signature
				from parent.

			
				CreateCRL returns a DER encoded CRL, signed by this Certificate, that
				contains the given list of revoked certificates.

				Note: this method does not generate an RFC 5280 conformant X.509 v2 CRL.
				To generate a standards compliant CRL, use CreateRevocationList instead.

			(*T) Equal(other *Certificate) bool
			
				Verify attempts to verify c by building one or more chains from c to a
				certificate in opts.Roots, using certificates in opts.Intermediates if
				needed. If successful, it returns one or more chains where the first
				element of the chain is c and the last element is from opts.Roots.

				If opts.Roots is nil, the platform verifier might be used, and
				verification details might differ from what is described below. If system
				roots are unavailable the returned error will be of type SystemRootsError.

				Name constraints in the intermediates will be applied to all names claimed
				in the chain, not just opts.DNSName. Thus it is invalid for a leaf to claim
				example.com if an intermediate doesn't permit it, even if example.com is not
				the name being validated. Note that DirectoryName constraints are not
				supported.

				Name constraint validation follows the rules from RFC 5280, with the
				addition that DNS name constraints may use the leading period format
				defined for emails and URIs. When a constraint has a leading period
				it indicates that at least one additional label must be prepended to
				the constrained name to be considered valid.

				Extended Key Usage values are enforced nested down a chain, so an intermediate
				or root that enumerates EKUs prevents a leaf from asserting an EKU not in that
				list. (While this is not specified, it is common practice in order to limit
				the types of certificates a CA can issue.)

				WARNING: this function doesn't do any revocation checking.

			
				VerifyHostname returns nil if c is a valid certificate for the named host.
				Otherwise it returns an error describing the mismatch.

				IP addresses can be optionally enclosed in square brackets and are checked
				against the IPAddresses field. Other names are checked case insensitively
				against the DNSNames field. If the names are valid hostnames, the certificate
				fields can have a wildcard as the left-most label.

				The legacy Common Name field is ignored unless it's a valid hostname, the
				certificate doesn't have any Subject Alternative Names, and the GODEBUG
				environment variable is set to "x509ignoreCN=0". Support for Common Name is
				deprecated will be entirely removed in the future.

			
		
			func ParseCertificate(asn1Data []byte) (*Certificate, error)
			func ParseCertificates(asn1Data []byte) ([]*Certificate, error)
			func (*Certificate).Verify(opts VerifyOptions) (chains [][]*Certificate, err error)
			
		
			func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv interface{}) (cert []byte, err error)
			func CreateRevocationList(rand io.Reader, template *RevocationList, issuer *Certificate, priv crypto.Signer) ([]byte, error)
			func (*Certificate).CheckSignatureFrom(parent *Certificate) error
			func (*Certificate).Equal(other *Certificate) bool
			func (*CertPool).AddCert(cert *Certificate)
			


	
		CertificateInvalidError results when an odd error occurs. Users of this
		library probably want to handle all these errors uniformly.

		
			Cert *Certificate
			Detail string
			Reason InvalidReason
		
			( T) Error() string
		
			 T : error


	
		CertificateRequest represents a PKCS #10, certificate signature request.

		
			
				Attributes contains the CSR attributes that can parse as
				pkix.AttributeTypeAndValueSET.

				Deprecated: Use Extensions and ExtraExtensions instead for parsing and
				generating the requestedExtensions attribute.

			
				Subject Alternate Name values.

			EmailAddresses []string
			
				Extensions contains all requested extensions, in raw form. When parsing
				CSRs, this can be used to extract extensions that are not parsed by this
				package.

			
				ExtraExtensions contains extensions to be copied, raw, into any CSR
				marshaled by CreateCertificateRequest. Values override any extensions
				that would otherwise be produced based on the other fields but are
				overridden by any extensions specified in Attributes.

				The ExtraExtensions field is not populated by ParseCertificateRequest,
				see Extensions instead.

			IPAddresses []net.IP
			PublicKey interface{}
			PublicKeyAlgorithm PublicKeyAlgorithm
			
				// Complete ASN.1 DER content (CSR, signature algorithm and signature).

			
				// DER encoded Subject.

			
				// DER encoded SubjectPublicKeyInfo.

			
				// Certificate request info part of raw ASN.1 DER content.

			Signature []byte
			SignatureAlgorithm SignatureAlgorithm
			Subject pkix.Name
			URIs []*url.URL
			Version int
		
			
				CheckSignature reports whether the signature on c is valid.

		
			func ParseCertificateRequest(asn1Data []byte) (*CertificateRequest, error)
			
		
			func CreateCertificateRequest(rand io.Reader, template *CertificateRequest, priv interface{}) (csr []byte, err error)
			


	
		CertPool is a set of certificates.

		
			
		
			
				AddCert adds a certificate to a pool.

			
				AppendCertsFromPEM attempts to parse a series of PEM encoded certificates.
				It appends any certificates found to s and reports whether any certificates
				were successfully parsed.

				On many Linux systems, /etc/ssl/cert.pem will contain the system wide set
				of root CAs in a format suitable for this function.

			
				Subjects returns a list of the DER-encoded subjects of
				all of the certificates in the pool.

			
		
			func NewCertPool() *CertPool
			func SystemCertPool() (*CertPool, error)
			
		
			


	
		ConstraintViolationError results when a requested usage is not permitted by
		a certificate. For example: checking a signature when the public key isn't a
		certificate signing key.

		
			( T) Error() string
		
			 T : error


	
		ExtKeyUsage represents an extended set of actions that are valid for a given key.
		Each of the ExtKeyUsage* constants define a unique action.

		
			
		
			
		
			const ExtKeyUsageAny
			const ExtKeyUsageClientAuth
			const ExtKeyUsageCodeSigning
			const ExtKeyUsageEmailProtection
			const ExtKeyUsageIPSECEndSystem
			const ExtKeyUsageIPSECTunnel
			const ExtKeyUsageIPSECUser
			const ExtKeyUsageMicrosoftCommercialCodeSigning
			const ExtKeyUsageMicrosoftKernelCodeSigning
			const ExtKeyUsageMicrosoftServerGatedCrypto
			const ExtKeyUsageNetscapeServerGatedCrypto
			const ExtKeyUsageOCSPSigning
			const ExtKeyUsageServerAuth
			const ExtKeyUsageTimeStamping


	
		HostnameError results when the set of authorized names doesn't match the
		requested name.

		
			Certificate *Certificate
			Host string
		
			( T) Error() string
		
			 T : error


	
		An InsecureAlgorithmError

		
			( T) Error() string
		
			 T : error


	
		KeyUsage represents the set of actions that are valid for a given key. It's
		a bitmap of the KeyUsage* constants.

		
			
		
			
		
			const KeyUsageCertSign
			const KeyUsageContentCommitment
			const KeyUsageCRLSign
			const KeyUsageDataEncipherment
			const KeyUsageDecipherOnly
			const KeyUsageDigitalSignature
			const KeyUsageEncipherOnly
			const KeyUsageKeyAgreement
			const KeyUsageKeyEncipherment


	

		
			func EncryptPEMBlock(rand io.Reader, blockType string, data, password []byte, alg PEMCipher) (*pem.Block, error)
			
		
			const PEMCipher3DES
			const PEMCipherAES128
			const PEMCipherAES192
			const PEMCipherAES256
			const PEMCipherDES


	

		
			( T) String() string
		
			 T : fmt.Stringer
			
		
			
		
			
		
			const DSA
			const ECDSA
			const Ed25519
			const RSA
			const UnknownPublicKeyAlgorithm


	
		RevocationList contains the fields used to create an X.509 v2 Certificate
		Revocation list with CreateRevocationList.

		
			
				ExtraExtensions contains any additional extensions to add directly to
				the CRL.

			
				NextUpdate is used to populate the nextUpdate field in the CRL, which
				indicates the date by which the next CRL will be issued. NextUpdate
				must be greater than ThisUpdate.

			
				Number is used to populate the X.509 v2 cRLNumber extension in the CRL,
				which should be a monotonically increasing sequence number for a given
				CRL scope and CRL issuer.

			
				RevokedCertificates is used to populate the revokedCertificates
				sequence in the CRL, it may be empty. RevokedCertificates may be nil,
				in which case an empty CRL will be created.

			
				SignatureAlgorithm is used to determine the signature algorithm to be
				used when signing the CRL. If 0 the default algorithm for the signing
				key will be used.

			
				ThisUpdate is used to populate the thisUpdate field in the CRL, which
				indicates the issuance date of the CRL.

		
			func CreateRevocationList(rand io.Reader, template *RevocationList, issuer *Certificate, priv crypto.Signer) ([]byte, error)


	

		
			( T) String() string
			
		
			 T : fmt.Stringer
			
		
			
		
			func (*Certificate).CheckSignature(algo SignatureAlgorithm, signed, signature []byte) error
			
		
			const DSAWithSHA1
			const DSAWithSHA256
			const ECDSAWithSHA1
			const ECDSAWithSHA256
			const ECDSAWithSHA384
			const ECDSAWithSHA512
			const MD2WithRSA
			const MD5WithRSA
			const PureEd25519
			const SHA1WithRSA
			const SHA256WithRSA
			const SHA256WithRSAPSS
			const SHA384WithRSA
			const SHA384WithRSAPSS
			const SHA512WithRSA
			const SHA512WithRSAPSS
			const UnknownSignatureAlgorithm


	
		SystemRootsError results when we fail to load the system root certificates.

		
			Err error
		
			( T) Error() string
			( T) Unwrap() error
		
			 T : error


	

		
			( T) Error() string
		
			 T : error


	
		UnknownAuthorityError results when the certificate issuer is unknown

		
			Cert *Certificate
			
		
			( T) Error() string
		
			 T : error


	
		VerifyOptions contains parameters for Certificate.Verify.

		
			
				CurrentTime is used to check the validity of all certificates in the
				chain. If zero, the current time is used.

			
				DNSName, if set, is checked against the leaf certificate with
				Certificate.VerifyHostname or the platform verifier.

			
				Intermediates is an optional pool of certificates that are not trust
				anchors, but can be used to form a chain from the leaf certificate to a
				root certificate.

			
				KeyUsages specifies which Extended Key Usage values are acceptable. A
				chain is accepted if it allows any of the listed values. An empty list
				means ExtKeyUsageServerAuth. To accept any key usage, include ExtKeyUsageAny.

			
				MaxConstraintComparisions is the maximum number of comparisons to
				perform when checking a given certificate's name constraints. If
				zero, a sensible default is used. This limit prevents pathological
				certificates from consuming excessive amounts of CPU time when
				validating. It does not apply to the platform verifier.

			
				Roots is the set of trusted root certificates the leaf certificate needs
				to chain up to. If nil, the system roots or the platform verifier are used.

		
			func (*Certificate).Verify(opts VerifyOptions) (chains [][]*Certificate, err error)
			


	


Package-Level Functions (total 83, in which 23 are exported)


	
		CreateCertificate creates a new X.509v3 certificate based on a template.
		The following members of template are used:

		 - AuthorityKeyId
		 - BasicConstraintsValid
		 - CRLDistributionPoints
		 - DNSNames
		 - EmailAddresses
		 - ExcludedDNSDomains
		 - ExcludedEmailAddresses
		 - ExcludedIPRanges
		 - ExcludedURIDomains
		 - ExtKeyUsage
		 - ExtraExtensions
		 - IPAddresses
		 - IsCA
		 - IssuingCertificateURL
		 - KeyUsage
		 - MaxPathLen
		 - MaxPathLenZero
		 - NotAfter
		 - NotBefore
		 - OCSPServer
		 - PermittedDNSDomains
		 - PermittedDNSDomainsCritical
		 - PermittedEmailAddresses
		 - PermittedIPRanges
		 - PermittedURIDomains
		 - PolicyIdentifiers
		 - SerialNumber
		 - SignatureAlgorithm
		 - Subject
		 - SubjectKeyId
		 - URIs
		 - UnknownExtKeyUsage

		The certificate is signed by parent. If parent is equal to template then the
		certificate is self-signed. The parameter pub is the public key of the
		signee and priv is the private key of the signer.

		The returned slice is the certificate in DER encoding.

		The currently supported key types are *rsa.PublicKey, *ecdsa.PublicKey and
		ed25519.PublicKey. pub must be a supported key type, and priv must be a
		crypto.Signer with a supported public key.

		The AuthorityKeyId will be taken from the SubjectKeyId of parent, if any,
		unless the resulting certificate is self-signed. Otherwise the value from
		template will be used.

		If SubjectKeyId from template is empty and the template is a CA, SubjectKeyId
		will be generated from the hash of the public key.


	
		CreateCertificateRequest creates a new certificate request based on a
		template. The following members of template are used:

		 - SignatureAlgorithm
		 - Subject
		 - DNSNames
		 - EmailAddresses
		 - IPAddresses
		 - URIs
		 - ExtraExtensions
		 - Attributes (deprecated)

		priv is the private key to sign the CSR with, and the corresponding public
		key will be included in the CSR. It must implement crypto.Signer and its
		Public() method must return a *rsa.PublicKey or a *ecdsa.PublicKey or a
		ed25519.PublicKey. (A *rsa.PrivateKey, *ecdsa.PrivateKey or
		ed25519.PrivateKey satisfies this.)

		The returned slice is the certificate request in DER encoding.


	
		CreateRevocationList creates a new X.509 v2 Certificate Revocation List,
		according to RFC 5280, based on template.

		The CRL is signed by priv which should be the private key associated with
		the public key in the issuer certificate.

		The issuer may not be nil, and the crlSign bit must be set in KeyUsage in
		order to use it as a CRL issuer.

		The issuer distinguished name CRL field and authority key identifier
		extension are populated using the issuer certificate. issuer must have
		SubjectKeyId set.


	
		DecryptPEMBlock takes a PEM block encrypted according to RFC 1423 and the
		password used to encrypt it and returns a slice of decrypted DER encoded
		bytes. It inspects the DEK-Info header to determine the algorithm used for
		decryption. If no DEK-Info header is present, an error is returned. If an
		incorrect password is detected an IncorrectPasswordError is returned. Because
		of deficiencies in the format, it's not always possible to detect an
		incorrect password. In these cases no error will be returned but the
		decrypted DER bytes will be random noise.

		Deprecated: Legacy PEM encryption as specified in RFC 1423 is insecure by
		design. Since it does not authenticate the ciphertext, it is vulnerable to
		padding oracle attacks that can let an attacker recover the plaintext.


	
		EncryptPEMBlock returns a PEM block of the specified type holding the
		given DER encoded data encrypted with the specified algorithm and
		password according to RFC 1423.

		Deprecated: Legacy PEM encryption as specified in RFC 1423 is insecure by
		design. Since it does not authenticate the ciphertext, it is vulnerable to
		padding oracle attacks that can let an attacker recover the plaintext.


	
		IsEncryptedPEMBlock returns whether the PEM block is password encrypted
		according to RFC 1423.

		Deprecated: Legacy PEM encryption as specified in RFC 1423 is insecure by
		design. Since it does not authenticate the ciphertext, it is vulnerable to
		padding oracle attacks that can let an attacker recover the plaintext.


	
		MarshalECPrivateKey converts an EC private key to SEC 1, ASN.1 DER form.

		This kind of key is commonly encoded in PEM blocks of type "EC PRIVATE KEY".
		For a more flexible key format which is not EC specific, use
		MarshalPKCS8PrivateKey.


	
		MarshalPKCS1PrivateKey converts an RSA private key to PKCS #1, ASN.1 DER form.

		This kind of key is commonly encoded in PEM blocks of type "RSA PRIVATE KEY".
		For a more flexible key format which is not RSA specific, use
		MarshalPKCS8PrivateKey.


	
		MarshalPKCS1PublicKey converts an RSA public key to PKCS #1, ASN.1 DER form.

		This kind of key is commonly encoded in PEM blocks of type "RSA PUBLIC KEY".


	
		MarshalPKCS8PrivateKey converts a private key to PKCS #8, ASN.1 DER form.

		The following key types are currently supported: *rsa.PrivateKey, *ecdsa.PrivateKey
		and ed25519.PrivateKey. Unsupported key types result in an error.

		This kind of key is commonly encoded in PEM blocks of type "PRIVATE KEY".


	
		MarshalPKIXPublicKey converts a public key to PKIX, ASN.1 DER form.
		The encoded public key is a SubjectPublicKeyInfo structure
		(see RFC 5280, Section 4.1).

		The following key types are currently supported: *rsa.PublicKey, *ecdsa.PublicKey
		and ed25519.PublicKey. Unsupported key types result in an error.

		This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY".


	
		NewCertPool returns a new, empty CertPool.


	
		ParseCertificate parses a single certificate from the given ASN.1 DER data.


	
		ParseCertificateRequest parses a single certificate request from the
		given ASN.1 DER data.


	
		ParseCertificates parses one or more certificates from the given ASN.1 DER
		data. The certificates must be concatenated with no intermediate padding.


	
		ParseCRL parses a CRL from the given bytes. It's often the case that PEM
		encoded CRLs will appear where they should be DER encoded, so this function
		will transparently handle PEM encoding as long as there isn't any leading
		garbage.


	
		ParseDERCRL parses a DER encoded CRL from the given bytes.


	
		ParseECPrivateKey parses an EC private key in SEC 1, ASN.1 DER form.

		This kind of key is commonly encoded in PEM blocks of type "EC PRIVATE KEY".


	
		ParsePKCS1PrivateKey parses an RSA private key in PKCS #1, ASN.1 DER form.

		This kind of key is commonly encoded in PEM blocks of type "RSA PRIVATE KEY".


	
		ParsePKCS1PublicKey parses an RSA public key in PKCS #1, ASN.1 DER form.

		This kind of key is commonly encoded in PEM blocks of type "RSA PUBLIC KEY".


	
		ParsePKCS8PrivateKey parses an unencrypted private key in PKCS #8, ASN.1 DER form.

		It returns a *rsa.PrivateKey, a *ecdsa.PrivateKey, or a ed25519.PrivateKey.
		More types might be supported in the future.

		This kind of key is commonly encoded in PEM blocks of type "PRIVATE KEY".


	
		ParsePKIXPublicKey parses a public key in PKIX, ASN.1 DER form.
		The encoded public key is a SubjectPublicKeyInfo structure
		(see RFC 5280, Section 4.1).

		It returns a *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey, or
		ed25519.PublicKey. More types might be supported in the future.

		This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY".


	
		SystemCertPool returns a copy of the system cert pool.

		On Unix systems other than macOS the environment variables SSL_CERT_FILE and
		SSL_CERT_DIR can be used to override the system default locations for the SSL
		certificate file and SSL certificate files directory, respectively. The
		latter can be a colon-separated list.

		Any mutations to the returned pool are not written to disk and do not affect
		any other pool returned by SystemCertPool.

		New changes in the system cert pool might not be reflected in subsequent calls.


	


Package-Level Variables (total 72, in which 2 are exported)


	
		ErrUnsupportedAlgorithm results from attempting to perform an operation that
		involves algorithms that are not currently implemented.


	
		IncorrectPasswordError is returned when an incorrect password is detected.


	


Package-Level Constants (total 71, in which 60 are exported)


	
		CANotAuthorizedForExtKeyUsage results when an intermediate or root
		certificate does not permit a requested extended key usage.


	
		CANotAuthorizedForThisName results when an intermediate or root
		certificate has a name constraint which doesn't permit a DNS or
		other name (including IP address) in the leaf certificate.


	const DSA PublicKeyAlgorithm = 2 // Unsupported.
	const DSAWithSHA1 SignatureAlgorithm = 7 // Unsupported.
	const DSAWithSHA256 SignatureAlgorithm = 8 // Unsupported.
	
		Expired results when a certificate has expired, based on the time
		given in the VerifyOptions.


	
		IncompatibleUsage results when the certificate's key usage indicates
		that it may only be used for a different purpose.


	const MD2WithRSA SignatureAlgorithm = 1 // Unsupported.
	const MD5WithRSA SignatureAlgorithm = 2 // Only supported for signing, not verification.
	
		NameConstraintsWithoutSANs results when a leaf certificate doesn't
		contain a Subject Alternative Name extension, but a CA certificate
		contains name constraints, and the Common Name can be interpreted as
		a hostname.

		This error is only returned when legacy Common Name matching is enabled
		by setting the GODEBUG environment variable to "x509ignoreCN=1". This
		setting might be removed in the future.


	
		NameMismatch results when the subject name of a parent certificate
		does not match the issuer name in the child.


	
		NotAuthorizedToSign results when a certificate is signed by another
		which isn't marked as a CA certificate.


	
		Possible values for the EncryptPEMBlock encryption algorithm.


	
		Possible values for the EncryptPEMBlock encryption algorithm.


	
		Possible values for the EncryptPEMBlock encryption algorithm.


	
		Possible values for the EncryptPEMBlock encryption algorithm.


	
		Possible values for the EncryptPEMBlock encryption algorithm.


	
		TooManyConstraints results when the number of comparison operations
		needed to check a certificate exceeds the limit set by
		VerifyOptions.MaxConstraintComparisions. This limit exists to
		prevent pathological certificates can consuming excessive amounts of
		CPU time to verify.


	
		TooManyIntermediates results when a path length constraint is
		violated.


	
		UnconstrainedName results when a CA certificate contains permitted
		name constraints, but leaf certificate contains a name of an
		unsupported or unconstrained type.