Class X509Certificate

Encapsulates an X509 certificate and provides read-only access to its information.

const { X509Certificate } = await import('crypto');

const x509 = new X509Certificate('{... pem encoded cert ...}');

console.log(x509.subject);

Since

v15.6.0

Constructors

constructor

Properties

ca fingerprint fingerprint256 fingerprint512 subject subjectAltName infoAccess keyUsage issuer issuerCertificate? publicKey raw serialNumber validFrom validTo

Methods

checkEmail checkHost checkIP checkIssued checkPrivateKey toJSON toLegacyObject toString verify

Constructors

constructor

Properties

Readonlyca

ca: boolean

Will be true if this is a Certificate Authority (CA) certificate.

Since

v15.6.0

Readonlyfingerprint

fingerprint: string

The SHA-1 fingerprint of this certificate.

Because SHA-1 is cryptographically broken and because the security of SHA-1 is significantly worse than that of algorithms that are commonly used to sign certificates, consider using x509.fingerprint256 instead.

Since

v15.6.0

Readonlyfingerprint256

fingerprint256: string

The SHA-256 fingerprint of this certificate.

Since

v15.6.0

Readonlyfingerprint512

fingerprint512: string

The SHA-512 fingerprint of this certificate.

Since

v16.14.0

Readonlysubject

subject: string

The complete subject of this certificate.

Since

v15.6.0

ReadonlysubjectAltName

subjectAltName: string

The subject alternative name specified for this certificate or undefined if not available.

Since

v15.6.0

ReadonlyinfoAccess

infoAccess: string

The information access content of this certificate or undefined if not available.

Since

v15.6.0

ReadonlykeyUsage

keyUsage: string[]

An array detailing the key usages for this certificate.

Since

v15.6.0

Readonlyissuer

issuer: string

The issuer identification included in this certificate.

Since

v15.6.0

Optional ReadonlyissuerCertificate

issuerCertificate?: X509Certificate

The issuer certificate or undefined if the issuer certificate is not available.

Since

v15.9.0

ReadonlypublicKey

publicKey: KeyObject

The public key KeyObject for this certificate.

Since

v15.6.0

Readonlyraw

raw: Buffer

A Buffer containing the DER encoding of this certificate.

Since

v15.6.0

ReadonlyserialNumber

serialNumber: string

The serial number of this certificate.

Serial numbers are assigned by certificate authorities and do not uniquely identify certificates. Consider using x509.fingerprint256 as a unique identifier instead.

Since

v15.6.0

ReadonlyvalidFrom

validFrom: string

The date/time from which this certificate is considered valid.

Since

v15.6.0

ReadonlyvalidTo

validTo: string

The date/time until which this certificate is considered valid.

Since

v15.6.0

Methods

checkEmail

  • checkEmail(email, options?): string

  • Checks whether the certificate matches the given email address.

    If the 'subject' option is undefined or set to 'default', the certificate subject is only considered if the subject alternative name extension either does not exist or does not contain any email addresses.

    If the 'subject' option is set to 'always' and if the subject alternative name extension either does not exist or does not contain a matching email address, the certificate subject is considered.

    If the 'subject' option is set to 'never', the certificate subject is never considered, even if the certificate contains no subject alternative names.

    Parameters

    Returns string

    Returns email if the certificate matches, undefined if it does not.

    Since

    v15.6.0

checkHost

  • checkHost(name, options?): string

  • Checks whether the certificate matches the given host name.

    If the certificate matches the given host name, the matching subject name is returned. The returned name might be an exact match (e.g., foo.example.com) or it might contain wildcards (e.g., *.example.com). Because host name comparisons are case-insensitive, the returned subject name might also differ from the given name in capitalization.

    If the 'subject' option is undefined or set to 'default', the certificate subject is only considered if the subject alternative name extension either does not exist or does not contain any DNS names. This behavior is consistent with RFC 2818 ("HTTP Over TLS").

    If the 'subject' option is set to 'always' and if the subject alternative name extension either does not exist or does not contain a matching DNS name, the certificate subject is considered.

    If the 'subject' option is set to 'never', the certificate subject is never considered, even if the certificate contains no subject alternative names.

    Parameters

    Returns string

    Returns a subject name that matches name, or undefined if no subject name matches name.

    Since

    v15.6.0

checkIP

  • checkIP(ip): string

  • Checks whether the certificate matches the given IP address (IPv4 or IPv6).

    Only RFC 5280 iPAddress subject alternative names are considered, and they must match the given ip address exactly. Other subject alternative names as well as the subject field of the certificate are ignored.

    Parameters

    • ip: string

    Returns string

    Returns ip if the certificate matches, undefined if it does not.

    Since

    v15.6.0

checkIssued

  • checkIssued(otherCert): boolean

  • Checks whether this certificate was issued by the given otherCert.

    Parameters

    Returns boolean

    Since

    v15.6.0

checkPrivateKey

  • checkPrivateKey(privateKey): boolean

  • Checks whether the public key for this certificate is consistent with the given private key.

    Parameters

    Returns boolean

    Since

    v15.6.0

toJSON

  • toJSON(): string

  • There is no standard JSON encoding for X509 certificates. ThetoJSON() method returns a string containing the PEM encoded certificate.

    Returns string

    Since

    v15.6.0

toLegacyObject

  • toLegacyObject(): PeerCertificate

  • Returns information about this certificate using the legacy certificate object encoding.

    Returns PeerCertificate

    Since

    v15.6.0

toString

  • toString(): string

  • Returns the PEM-encoded certificate.

    Returns string

    Since

    v15.6.0

verify

  • verify(publicKey): boolean

  • Verifies that this certificate was signed by the given public key. Does not perform any other validation checks on the certificate.

    Parameters

    Returns boolean

    Since

    v15.6.0

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