Cert C# WinRT Reference Documentation

Cert

Digital certificate component / class

Object Creation

Chilkat.Cert obj = new Chilkat.Cert();

Properties

public string AuthorityKeyId {get; }

Introduced in version 9.5.0.40

The authority key identifier of the certificate in base64 string format. This is only present if the certificate contains the extension OID 2.5.29.35.

public bool AvoidWindowsPkAccess {get; set; }

Applies only when running on a Microsoft Windows operating system. If true, then any method that returns a certificate will not try to also access the associated private key, assuming one exists. This is useful if the certificate was installed with high-security such that a private key access would trigger the Windows OS to display a security warning dialog. The default value of this property is false.

public int CertVersion {get; }

The version of the certificate (1, 2, or 3). A value of 0 indicates an error -- the most likely cause being that the certificate object is empty (i.e. was never loaded with a certificate). Note: This is not the version of the software, it is the version of the X.509 certificate object. The version of the Chilkat certificate software is indicated by the Version property.

public string CspName {get; }

(Relevant only when running on a Microsoft Windows operating system.) If the HasKeyContainer property is true, then the certificate is linked to a key container and this property contains the name of the associated CSP (cryptographic service provider). When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

public string DebugLogFilePath {get; set; }

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

public bool Expired {get; }

Has a value of true if the certificate or any certificate in the chain of authority has expired. (This information is not available when running on Windows 95/98 computers.)

public bool ForClientAuthentication {get; }

true if this certificate can be used for client authentication, otherwise false.

public bool ForCodeSigning {get; }

true if this certificate can be used for code signing, otherwise false.

public bool ForSecureEmail {get; }

true if this certificate can be used for sending secure email, otherwise false.

public bool ForServerAuthentication {get; }

true if this certificate can be used for server authentication, otherwise false.

public bool ForTimeStamping {get; }

true if this certificate can be used for time stamping, otherwise false.

public bool HasKeyContainer {get; }

(Relevant only when running on a Microsoft Windows operating system.) Indicates whether this certificate is linked to a key container. If true then the certificate is linked to a key container (usually containing a private key). If false, then it is not.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

public uint IntendedKeyUsage {get; }

Bitflags indicating the intended usages of the certificate. The flags are:
Digital Signature: 0x80
Non-Repudiation: 0x40
Key Encipherment: 0x20
Data Encipherment: 0x10
Key Agreement: 0x08
Certificate Signing: 0x04
CRL Signing: 0x02
Encipher-Only: 0x01

public bool IsRoot {get; }

true if this is the root certificate, otherwise false.

public string IssuerC {get; }

The certificate issuer's country.

public string IssuerCN {get; }

The certificate issuer's common name.

public string IssuerDN {get; }

The issuer's full distinguished name.

public string IssuerE {get; }

The certificate issuer's email address.

public string IssuerL {get; }

The certificate issuer's locality, which could be a city, count, township, or other geographic region.

public string IssuerO {get; }

The certificate issuer's organization, which is typically the company name.

public string IssuerOU {get; }

The certificate issuer's organizational unit, which is the unit within the organization.

public string IssuerS {get; }

The certificate issuer's state or province.

public string KeyContainerName {get; }

(Relevant only when running on a Microsoft Windows operating system.) If the HasKeyContainer property is true, then the certificate is linked to a key container and this property contains the name of the key container.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

public string LastErrorHtml {get; }

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

public string LastErrorText {get; }

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Concept of LastErrorText

LastErrorText Standard Information

public string LastErrorXml {get; }

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

public bool LastMethodSuccess {get; set; }

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of true indicates success, a value of false indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = true and failure = false.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to true. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

public bool MachineKeyset {get; }

(Relevant only when running on a Microsoft Windows operating system.) If the HasKeyContainer property is true, then the certificate is linked to a key container and this property indicates whether the key container is in the machine's keyset or in the keyset specific to the logged on user's account. If true, the key container is within the machine keyset. If false, it's in the user's keyset.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

public string OcspUrl {get; }

If present in the certificate's extensions, returns the OCSP URL of the certificate. (The Online Certificate Status Protocol (OCSP) is an Internet protocol used for obtaining the revocation status of an X.509 digital certificate.)

public bool PrivateKeyExportable {get; }

(Relevant only when running on a Microsoft Windows operating system.) Indicates whether the private key was installed with security settings that allow it to be re-exported.

Backup Windows Current User / Personal Certificates to a .zip

public bool Revoked {get; }

true if the certificate or any certificate in the chain of authority has been revoked. This information is not available when running on Windows 95/98 computers. Note: If this property is false, it could mean that it was not able to check the revocation status. Because of this uncertainty, a CheckRevoked method has been added. It returns an integer indicating one of three possible states: 1 (revoked) , 0 (not revoked), -1 (unable to check revocation status).

public string Rfc822Name {get; }

The RFC-822 name of the certificate. (Also known as the Subject Alternative Name.)

If the certificate contains a list of Subject Alternative Names, such as a list of host names to be protected by a single SSL certificate, then this property will contain the comma separated list of names.

public bool SelfSigned {get; }

true if this is a self-signed certificate, otherwise false.

public string SerialNumber {get; }

The certificate's serial number as a hexidecimal string.

public string Sha1Thumbprint {get; }

Hexidecimal string of the SHA-1 thumbprint for the certificate.

public bool SignatureVerified {get; }

Returns true if the certificate and all certificates in the chain of authority have valid signatures, otherwise returns false.

public bool Silent {get; }

(Relevant only when running on a Microsoft Windows operating system.) If the HasKeyContainer property is true, then the certificate is linked to a key container and this property indicates whether accessing the private key will cause the operating system to launch an interactive warning dialog. If false a warning dialog will be displayed. If true then private key accesses are silent.

When a certificate is linked to a key container , the following properties will provide information about the key container and private key: CspName, KeyContainerName, MachineKeyset, and Silent.

public string SubjectC {get; }

The certificate subject's country.

public string SubjectCN {get; }

The certificate subject's common name.

public string SubjectDN {get; }

The certificate subject's full distinguished name.

public string SubjectE {get; }

The certificate subject's email address.

public string SubjectKeyId {get; }

Introduced in version 9.5.0.40

The subject key identifier of the certificate in base64 string format. This is only present if the certificate contains the extension OID 2.5.29.14.

public string SubjectL {get; }

The certificate subject's locality, which could be a city, count, township, or other geographic region.

public string SubjectO {get; }

The certificate subject's organization, which is typically the company name.

public string SubjectOU {get; }

The certificate subject's organizational unit, which is the unit within the organization.

public string SubjectS {get; }

The certificate subject's state or province.

public bool TrustedRoot {get; }

Returns true if the certificate has a trusted root authority, otherwise returns false.

Note: As of version 9.5.0.41, the notion of what your application deems as trusted becomes more specific. The TrustedRoots class/object was added in v9.5.0.0. Prior to this, a certificate was considered to be anchored by a trusted root if the certificate chain could be established to a root (self-signed) certificate, AND if the root certificate was located somewhere in the Windows registry-based certificate stores. There are two problems with this: (1) it's a Windows-only solution. This property would always return false on non-Windows systems, and (2) it might be considered not a strong enough set of conditions for trusting a root certificate.

As of version 9.5.0.41, this property pays attention to the new TrustedRoots class/object, which allows for an application to specificallly indicate which root certificates are to be trusted. Certificates may be added to the TrustedRoots object via the LoadCaCertsPem or AddCert methods, and then activated by calling the TrustedRoots.Activate method. The activated trusted roots are deemed to be trusted in any Chilkat API method/property that needs to make this determination. In addition, the TrustedRoots object has a property named TrustSystemCaRoots, which defaults to true, which allows for backward compatibility. It will trust CA certificates stored in the Windows registry-based certificate stores, or if on Linux, will trust certificates found in /etc/ssl/certs/ca-certificates.crt.

public string ValidFromStr {get; }

The date (in RFC822 string format) that this certificate becomes (or became) valid. It is a GMT/UTC date that is returned.

public string ValidToStr {get; }

The date (in RFC822 string format) that this certificate becomes (or became) invalid. It is a GMT/UTC date that is returned.

public bool VerboseLogging {get; set; }

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

public string Version {get; }

Version of the component/library, such as "9.5.0.63"

Methods

public int CheckRevoked();

Returns 1 if the certificate has been revoked, 0 if not revoked, and -1 if unable to check the revocation status.

public byte[] ExportCertDer();

Exports the digital certificate to ASN.1 DER format.

Returns an empty byte array on failure

public bool ExportCertDerBd(BinData cerData);

Introduced in version 9.5.0.70

Exports the digital certificate in ASN.1 DER format to a BinData object.

Returns true for success, false for failure.

Backup Windows Current User / Personal Certificates to a .zip

public bool ExportCertDerFile(string path);

Exports the digital certificate to ASN.1 DER format binary file.

Returns true for success, false for failure.

public string ExportCertPem();

Exports the digital certificate to an unencrypted PEM formatted string.

Returns null on failure

public bool ExportCertPemFile(string path);

Exports the digital certificate to an unencrypted PEM formatted file.

Returns true for success, false for failure.

public string ExportCertXml();

Exports a certificate to an XML format where the XML tags are the names of the ASN.1 objects that compose the X.509 certificate. Binary data is either hex or base64 encoded. (The binary data for a "bits" ASN.1 tag is hex encoded, whereas for all other ASN.1 tags, such as "octets", it is base64.)

Returns null on failure

Get Certificate As XML (and gets Signature Algorithm Identifier)

public PrivateKey ExportPrivateKey();

Exports the certificate's private key.

Returns null on failure

public PublicKey ExportPublicKey();

Exports the certificate's public key.

Returns null on failure

Get RSA Key Modulus from .cer or .key

public bool ExportToPfxBd(string password, bool includeCertChain, BinData pfxData);

Introduced in version 9.5.0.70

Exports the certificate and private key (if available) to pfxData. The password is what will be required to access the PFX contents at a later time. If includeCertChain is true, then the certificates in the chain of authority are also included in the PFX.

Returns true for success, false for failure.

Backup Windows Current User / Personal Certificates to a .zip

public byte[] ExportToPfxData(string password, bool includeCertChain);

Introduced in version 9.5.0.31

Exports the certificate and private key (if available) to an in-memory PFX image. The password is what will be required to access the PFX contents at a later time. If includeCertChain is true, then the certificates in the chain of authority are also included in the PFX.

Returns an empty byte array on failure

public bool ExportToPfxFile(string pfxFilename, string pfxPassword, bool bIncludeCertChain);

Exports the certificate and private key (if available) to a PFX (.pfx or .p12) file. The output PFX is secured using the pfxPassword. If bIncludeCertChain is true, then the certificates in the chain of authority are also included in the PFX output file.

Returns true for success, false for failure.

public Cert FindIssuer();

Finds and returns the issuer certificate. If the certificate is a root or self-issued, then the certificate returned is a copy of the caller certificate. (The IsRoot property can be check to see if the certificate is a root (or self-issued) certificate.)

Returns null on failure

public CertChain GetCertChain();

Introduced in version 9.5.0.40

Returns a certficate chain object containing all the certificates (including this one), in the chain of authentication to the trusted root (if possible). If this certificate object was loaded from a PFX, then the certiicates contained in the PFX are automatically available for building the certificate chain. The UseCertVault method can be called to provide additional certificates that might be required to build the cert chain. Finally, the TrustedRoots object can be used to provide a way of making trusted root certificates available.

Note: Prior to v9.5.0.50, this method would fail if the certificate chain could not be completed to the root. Starting in v9.5.0.50, the incomplete certificate chain will be returned. The certificate chain's ReachesRoot property can be examined to see if the chain was completed to the root.

On Windows systems, the registry-based certificate stores are automatically consulted if needed to locate intermediate or root certificates in the chain.

Returns null on failure

Get the Server Certificate, Certificate Chain, and Root CA Certificate

public string GetEncoded();

Returns a base64 encoded string representation of the certificate's binary DER format, which can be passed to SetFromEncoded to recreate the certificate object.

Returns null on failure

public string GetExtensionAsXml(string oid);

Introduced in version 9.5.0.49

Returns the certificate extension data in XML format (converted from ASN.1). The oid is an OID, such as the ones listed here: http://www.alvestrand.no/objectid/2.5.29.html

Note: In many cases, the data within the XML is returned base64 encoded. An application may need to take one further step to base64 decode the information contained within the XML.

Returns null on failure

public string GetPrivateKeyPem();

Exports the certificate's private key to a PEM string (if the private key is available).

Returns null on failure

public string GetSpkiFingerprint(string hashAlg, string encoding);

Introduced in version 9.5.0.55

Returns the SPKI Fingerprint suitable for use in pinning. (See RFC 7469.) An SPKI Fingerprint is defined as the output of a known cryptographic hash algorithm whose input is the DER-encoded ASN.1 representation of the Subject Public Key Info (SPKI) of an X.509 certificate. The hashAlg specifies the hash algorithm and may be "sha256", "sha384", "sha512", "sha1", "md2", "md5", "haval", "ripemd128", "ripemd160","ripemd256", or "ripemd320". The encoding specifies the encoding, and may be "base64", "hex", or any of the encoding modes specified in the article at the link below.

Returns null on failure

List of Chilkat Encoding Modes

SPKI Fingerprint

public CkDateTime GetValidFromDt();

Returns the date/time this certificate becomes (or became) valid.

Returns null on failure

public CkDateTime GetValidToDt();

Returns the date/time this certificate becomes (or became) invalid.

Returns null on failure

public bool HasPrivateKey();

Returns true if the private key is installed on the local system for the certificate.

public bool LoadByCommonName(string cn);

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate having the common name specified. If found, the certificate is loaded and ready for use.

Returns true for success, false for failure.

Select Cert for Encrypted Email

Create P7M Using Pre-Installed Windows Certificate

public bool LoadByEmailAddress(string emailAddress);

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate containing the email address specified. If found, the certificate is loaded and ready for use.

Returns true for success, false for failure.

Select Cert for Encrypted Email

public bool LoadByIssuerAndSerialNumber(string issuerCN, string serialNumber);

(Relevant only when running on a Microsoft Windows operating system.) Searches the Windows Local Machine and Current User registry-based certificate stores for a certificate matching the issuerCN and having an issuer matching the serialNumber. If found, the certificate is loaded and ready for use.

Returns true for success, false for failure.

public bool LoadFromBase64(string encodedCert);

Loads an ASN.1 or DER encoded certificate represented in a Base64 string.

Returns true for success, false for failure.

Get a Certificate's Key Size

public bool LoadFromBd(BinData certBytes);

Introduced in version 9.5.0.70

Loads an X.509 certificate from the ASN.1 DER encoded bytes contained in certBytes.

Returns true for success, false for failure.

public bool LoadFromBinary(byte[] data);

Loads an X.509 certificate from ASN.1 DER encoded bytes.

Returns true for success, false for failure.

public bool LoadFromFile(string path);

Loads a certificate from a .cer, .crt, .p7b, or .pem file. This method accepts certificates from files in any of the following formats:
1. DER encoded binary X.509 (.CER)
2. Base-64 encoded X.509 (.CER)
3. Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)
4. PEM format
This method decodes the certificate based on the contents if finds within the file, and not based on the file extension. If your certificate is in a file having a different extension, try loading it using this method before assuming it won't work. This method does not load .p12 or .pfx (PKCS #12) files.

Returns true for success, false for failure.

public bool LoadPem(string strPem);

Introduced in version 9.5.0.49

Loads the certificate from a PEM string.

Returns true for success, false for failure.

Load Certificate from PEM and Access the Public Key

public bool LoadPfxBd(BinData pfxData, string password);

Introduced in version 9.5.0.70

Loads the certificate from the PFX contained in pfxData. Note: If the PFX contains multiple certificates, the 1st certificate in the PFX is loaded.

Returns true for success, false for failure.

public bool LoadPfxData(byte[] pfxData, string password);

Loads a PFX from an in-memory image of a PFX file. Note: If the PFX contains multiple certificates, the 1st certificate in the PFX is loaded.

Returns true for success, false for failure.

public bool LoadPfxFile(string pfxPath, string password);

Loads a PFX file. Note: If the PFX contains multiple certificates, the 1st certificate in the PFX is loaded.

Returns true for success, false for failure.

public bool PemFileToDerFile(string fromPath, string toPath);

Converts a PEM file to a DER file.

Returns true for success, false for failure.

public bool SaveToFile(string path);

Saves a certificate object to a .cer file.

Returns true for success, false for failure.

public bool SetFromEncoded(string encodedCert);

Initializes the certificate object from a base64 encoded string representation of the certificate's binary DER format.

Returns true for success, false for failure.

public bool SetPrivateKey(PrivateKey privKey);

Used to associate a private key with the certificate for subsequent (PKCS7) signature creation or decryption.

Returns true for success, false for failure.

public bool SetPrivateKeyPem(string privKeyPem);

Same as SetPrivateKey, but the key is provided in unencrypted PEM format. (Note: The privKeyPem is not a file path, it is the actual PEM text.)

Returns true for success, false for failure.

public bool UseCertVault(XmlCertVault vault);

Introduced in version 9.5.0.40

Adds an XML certificate vault to the object's internal list of sources to be searched for certificates for help in building certificate chains and verifying the certificate signature to the trusted root.

Returns true for success, false for failure.

public bool VerifySignature();

Introduced in version 9.5.0.40

Verifies the certificate signature, as well as the signatures of all certificates in the chain of authentication to the trusted root. Returns true if all signatures are verified to the trusted root. Otherwise returns false.