---
product: Chilkat
product_version: 11.7.0
language: objc
language_label: Objective-C
class: Cert
class_name: CkoCert
license: free
deprecated: false
reference_html: https://www.chilkatsoft.com/refdoc/objcCkoCertRef.html
---
# Chilkat Cert — Objective-C — v11.7.0

> Chilkat 11.7.0 · language=objc · class=Cert (CkoCert)
> Other versions: replace `11.7.0` in this URL. Other languages: `https://www.chilkatsoft.com/ai-docs/v/11.7.0/<lang>/classes/Cert.md`.
> Language-wide rules (install, unlock, error model, strings/bytes): `https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/guide.md`.

## Purpose

**Load, inspect, validate, and use X.509 certificates throughout Chilkat.**

`Chilkat.Cert` is the central certificate object used throughout Chilkat for TLS, S/MIME, PKCS7/CMS, PDF signing, XML signing, code signing, decryption, certificate stores, smart cards, HSMs, PKCS#11, and cloud-based signing. It provides a broad set of features for loading certificates, inspecting certificate fields, checking validity, accessing private keys, building chains, checking revocation status, exporting certificate data, and diagnosing certificate-related problems.

**Load certificates**

Load public certificates from PEM, DER, Base64, files, strings, binary data, certificate stores, PFX/P12 files, smart cards, and other sources.

**Inspect certificate details**

Read subject and issuer fields, serial numbers, fingerprints, validity dates, key usage, extensions, SAN values, and other X.509 information.

**Private key access**

Work with certificates backed by private keys from PFX/P12 files, OS certificate stores, smart cards, HSMs, PKCS#11 modules, or cloud signing providers.

**Trust and validation**

Build and inspect certificate chains, verify signatures, check expiration, examine trust-related information, and work with revocation data.

**Use across Chilkat**

Pass `Cert` objects to other Chilkat classes for TLS client authentication, S/MIME, signing, encryption, decryption, and verification.

**Export and diagnostics**

Export certificate data in common formats and use detailed diagnostic output to troubleshoot loading, validation, private-key, chain, or store problems.

**Common pattern:** Use certificate-only formats such as PEM or DER when only the public certificate is needed. Use PFX/P12, an OS certificate store, smart-card loading, PKCS#11 linking, HSM integration, or cloud-signing configuration when a private key operation is required.

For an extended overview, see [Cert Class Overview](https://www.chilkatsoft.com/cert_class_overview.asp).

## Object creation, unlocking and error handling

**Object Creation**

```objectivec
CkoCert *obj = [[CkoCert alloc] init];
```

Call `Global.UnlockBundle` once at the start of the program, before using this or any other Chilkat class. Any string unlocks a fully functional 30-day trial; a purchased unlock code is used in production. See `guide.md` for the exact code in Objective-C.

How failure is reported depends on the method's return type and is stated in the note under each method below. In every case the diagnostic text is in the `LastErrorText` property of the object whose method was called.

## Members common to every Chilkat class

Documented once per language in `common-members.md`; listed here so this page is self-contained.

| Property | Signature | Access | Meaning |
|---|---|---|---|
| `DebugLogFilePath` | `@property (nonatomic, copy) NSString *DebugLogFilePath;` | read/write | If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. |
| `LastErrorHtml` | `@property (nonatomic, readonly, copy) NSString *LastErrorHtml;` | read-only | Provides HTML-formatted information about the last called method or property. |
| `LastErrorText` | `@property (nonatomic, readonly, copy) NSString *LastErrorText;` | read-only | Provides plain text information about the last called method or property. |
| `LastErrorXml` | `@property (nonatomic, readonly, copy) NSString *LastErrorXml;` | read-only | Provides XML-formatted information about the last called method or property. |
| `LastMethodSuccess` | `@property (nonatomic) BOOL LastMethodSuccess;` | read/write | Indicates the success or failure of the most recent method call: `YES` means success, `NO` means failure. |
| `VerboseLogging` | `@property (nonatomic) BOOL VerboseLogging;` | read/write | If set to `YES`, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. |
| `Version` | `@property (nonatomic, readonly, copy) NSString *Version;` | read-only | Version of the component/library, such as "10.1.0" |

## Member index

| Member | Kind | Signature |
|---|---|---|
| `AuthorityKeyId` | property, read-only | `@property (nonatomic, readonly, copy) NSString *AuthorityKeyId;` |
| `CertVersion` | property, read-only | `@property (nonatomic, readonly, copy) NSNumber *CertVersion;` |
| `Expired` | property, read-only | `@property (nonatomic, readonly) BOOL Expired;` |
| `ExtendedKeyUsage` | property, read-only | `@property (nonatomic, readonly, copy) NSString *ExtendedKeyUsage;` |
| `ForClientAuthentication` | property, read-only | `@property (nonatomic, readonly) BOOL ForClientAuthentication;` |
| `ForCodeSigning` | property, read-only | `@property (nonatomic, readonly) BOOL ForCodeSigning;` |
| `ForSecureEmail` | property, read-only | `@property (nonatomic, readonly) BOOL ForSecureEmail;` |
| `ForServerAuthentication` | property, read-only | `@property (nonatomic, readonly) BOOL ForServerAuthentication;` |
| `ForTimeStamping` | property, read-only | `@property (nonatomic, readonly) BOOL ForTimeStamping;` |
| `IntendedKeyUsage` | property, read-only | `@property (nonatomic, readonly, copy) NSNumber *IntendedKeyUsage;` |
| `IsRoot` | property, read-only | `@property (nonatomic, readonly) BOOL IsRoot;` |
| `IssuerC` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerC;` |
| `IssuerCN` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerCN;` |
| `IssuerDN` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerDN;` |
| `IssuerE` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerE;` |
| `IssuerL` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerL;` |
| `IssuerO` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerO;` |
| `IssuerOU` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerOU;` |
| `IssuerS` | property, read-only | `@property (nonatomic, readonly, copy) NSString *IssuerS;` |
| `OcspUrl` | property, read-only | `@property (nonatomic, readonly, copy) NSString *OcspUrl;` |
| `PrivateKeyExportable` | property, read-only | `@property (nonatomic, readonly) BOOL PrivateKeyExportable;` |
| `Revoked` | property, read-only | `@property (nonatomic, readonly) BOOL Revoked;` |
| `Rfc822Name` | property, read-only | `@property (nonatomic, readonly, copy) NSString *Rfc822Name;` |
| `SelfSigned` | property, read-only | `@property (nonatomic, readonly) BOOL SelfSigned;` |
| `SerialDecimal` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SerialDecimal;` |
| `SerialNumber` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SerialNumber;` |
| `Sha1Thumbprint` | property, read-only | `@property (nonatomic, readonly, copy) NSString *Sha1Thumbprint;` |
| `SignatureVerified` | property, read-only | `@property (nonatomic, readonly) BOOL SignatureVerified;` |
| `SmartCardFailReason` | property, read-only | `@property (nonatomic, readonly, copy) NSNumber *SmartCardFailReason;` |
| `SmartCardPin` | property, read/write | `@property (nonatomic, copy) NSString *SmartCardPin;` |
| `SubjectAlternativeName` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectAlternativeName;` |
| `SubjectC` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectC;` |
| `SubjectCN` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectCN;` |
| `SubjectDN` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectDN;` |
| `SubjectE` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectE;` |
| `SubjectKeyId` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectKeyId;` |
| `SubjectL` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectL;` |
| `SubjectO` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectO;` |
| `SubjectOU` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectOU;` |
| `SubjectS` | property, read-only | `@property (nonatomic, readonly, copy) NSString *SubjectS;` |
| `TrustedRoot` | property, read-only | `@property (nonatomic, readonly) BOOL TrustedRoot;` |
| `UncommonOptions` | property, read/write | `@property (nonatomic, copy) NSString *UncommonOptions;` |
| `ValidFromStr` | property, read-only | `@property (nonatomic, readonly, copy) NSString *ValidFromStr;` |
| `ValidToStr` | property, read-only | `@property (nonatomic, readonly, copy) NSString *ValidToStr;` |
| `BuildCertChain` | method | `- (BOOL)BuildCertChain:(CkoCertChain *)certChain;` |
| `CheckSmartCardPin` | method | `- (NSNumber *)CheckSmartCardPin;` |
| `ExportCertDer` | method | `- (NSData *)ExportCertDer;` |
| `ExportCertDerBd` | method | `- (BOOL)ExportCertDerBd:(CkoBinData *)cerData;` |
| `ExportCertDerFile` | method | `- (BOOL)ExportCertDerFile:(NSString *)path;` |
| `ExportCertPem` | method | `- (NSString *)ExportCertPem;` |
| `ExportCertPemFile` | method | `- (BOOL)ExportCertPemFile:(NSString *)path;` |
| `ExportCertXml` | method | `- (NSString *)ExportCertXml;` |
| `ExportToPfxBd` | method | `- (BOOL)ExportToPfxBd:(NSString *)password     includeCertChain:(BOOL)includeCertChain     pfxData:(CkoBinData *)pfxData;` |
| `ExportToPfxData` | method | `- (NSData *)ExportToPfxData:(NSString *)password     includeCertChain:(BOOL)includeCertChain;` |
| `ExportToPfxFile` | method | `- (BOOL)ExportToPfxFile:(NSString *)pfxFilename     pfxPassword:(NSString *)pfxPassword     bIncludeCertChain:(BOOL)bIncludeCertChain;` |
| `FindIssuer` | method | `- (CkoCert *)FindIssuer;` |
| `GetEncoded` | method | `- (NSString *)GetEncoded;` |
| `GetExtensionAsText` | method | `- (NSString *)GetExtensionAsText:(NSString *)oid;` |
| `GetExtensionAsXml` | method | `- (NSString *)GetExtensionAsXml:(NSString *)oid;` |
| `GetExtensionBd` | method | `- (BOOL)GetExtensionBd:(NSString *)oid     bd:(CkoBinData *)bd;` |
| `GetIssuer` | method | `- (BOOL)GetIssuer:(CkoCert *)issuer;` |
| `GetPrivateKey` | method | `- (BOOL)GetPrivateKey:(CkoPrivateKey *)privKey;` |
| `GetPrivateKeyPem` | method | `- (NSString *)GetPrivateKeyPem;` |
| `GetPubKeyDer` | method | `- (BOOL)GetPubKeyDer:(BOOL)preferPkcs1     bd:(CkoBinData *)bd;` |
| `GetPublicKey` | method | `- (BOOL)GetPublicKey:(CkoPublicKey *)pubKey;` |
| `GetSignature` | method | `- (BOOL)GetSignature:(CkoBinData *)bd;` |
| `GetSpkiFingerprint` | method | `- (NSString *)GetSpkiFingerprint:(NSString *)hashAlg     encoding:(NSString *)encoding;` |
| `GetSubjectPart` | method | `- (NSString *)GetSubjectPart:(NSString *)partNameOrOid;` |
| `HashOf` | method | `- (NSString *)HashOf:(NSString *)part     hashAlg:(NSString *)hashAlg     encoding:(NSString *)encoding;` |
| `HasPrivateKey` | method | `- (BOOL)HasPrivateKey;` |
| `IsEcdsa` | method | `- (BOOL)IsEcdsa;` |
| `IsRsa` | method | `- (BOOL)IsRsa;` |
| `LinkPkcs11` | method | `- (BOOL)LinkPkcs11:(CkoPkcs11 *)session;` |
| `LoadByCommonName` | method | `- (BOOL)LoadByCommonName:(NSString *)cn;` |
| `LoadByEmailAddress` | method | `- (BOOL)LoadByEmailAddress:(NSString *)emailAddress;` |
| `LoadByIssuerAndSerialNumber` | method | `- (BOOL)LoadByIssuerAndSerialNumber:(NSString *)issuerCN     serialNumber:(NSString *)serialNumber;` |
| `LoadBySubjectOid` | method | `- (BOOL)LoadBySubjectOid:(NSString *)oid     value:(NSString *)value;` |
| `LoadByThumbprint` | method | `- (BOOL)LoadByThumbprint:(NSString *)thumbprint     encoding:(NSString *)encoding;` |
| `LoadFromBase64` | method | `- (BOOL)LoadFromBase64:(NSString *)encodedCert;` |
| `LoadFromBd` | method | `- (BOOL)LoadFromBd:(CkoBinData *)certBytes;` |
| `LoadFromBinary` | method | `- (BOOL)LoadFromBinary:(NSData *)data;` |
| `LoadFromFile` | method | `- (BOOL)LoadFromFile:(NSString *)path;` |
| `LoadFromSmartcard` | method | `- (BOOL)LoadFromSmartcard:(NSString *)certSpec;` |
| `LoadPem` | method | `- (BOOL)LoadPem:(NSString *)strPem;` |
| `LoadPfxBd` | method | `- (BOOL)LoadPfxBd:(CkoBinData *)pfxData     password:(NSString *)password;` |
| `LoadPfxData` | method | `- (BOOL)LoadPfxData:(NSData *)pfxData     password:(NSString *)password;` |
| `LoadPfxFile` | method | `- (BOOL)LoadPfxFile:(NSString *)path     password:(NSString *)password;` |
| `LoadTaskResult` | method | `- (BOOL)LoadTaskResult:(CkoTask *)task;` |
| `PemFileToDerFile` | method | `- (BOOL)PemFileToDerFile:(NSString *)fromPath     toPath:(NSString *)toPath;` |
| `SaveToFile` | method | `- (BOOL)SaveToFile:(NSString *)path;` |
| `SetCloudSigner` | method | `- (BOOL)SetCloudSigner:(CkoJsonObject *)json;` |
| `SetFromEncoded` | method | `- (BOOL)SetFromEncoded:(NSString *)encodedCert;` |
| `SetPrivateKey` | method | `- (BOOL)SetPrivateKey:(CkoPrivateKey *)privKey;` |
| `SetPrivateKeyPem` | method | `- (BOOL)SetPrivateKeyPem:(NSString *)privKeyPem;` |
| `Unload` | method | `- (BOOL)Unload;` |
| `UploadToCloud` | method | `- (BOOL)UploadToCloud:(CkoJsonObject *)jsonIn     jsonOut:(CkoJsonObject *)jsonOut;` |
| `UseCertVault` | method | `- (BOOL)UseCertVault:(CkoXmlCertVault *)vault;` |
| `VerifySignature` | method | `- (BOOL)VerifySignature;` |
| `X509PKIPathv1` | method | `- (NSString *)X509PKIPathv1;` |

Deprecated members are listed at the end of this file with their replacements; do not use them in new code.

## Properties

### Cert.AuthorityKeyId

`Chilkat 11.7.0 · objc · Cert · AuthorityKeyId · property · read-only · since 9.5.0.40`

```objectivec
@property (nonatomic, readonly, copy) NSString *AuthorityKeyId;
```

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.

### Cert.CertVersion

`Chilkat 11.7.0 · objc · Cert · CertVersion · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSNumber *CertVersion;
```

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.

### Cert.Expired

`Chilkat 11.7.0 · objc · Cert · Expired · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL Expired;
```

Has a value of `YES` 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.)

### Cert.ExtendedKeyUsage

`Chilkat 11.7.0 · objc · Cert · ExtendedKeyUsage · property · read-only · since 9.5.0.85`

```objectivec
@property (nonatomic, readonly, copy) NSString *ExtendedKeyUsage;
```

Returns a string containing a comma separated list of keywords with the extended key usages of the certificate. The list of possible extended key usages are:

- serverAuth - TLS WWW server authentication
- clientAuth - TLS WWW client authentication
- codeSigning - Signing of downloadable executable code
- emailProtection - Email protection
- timeStamping - Binding the hash of an object to a time
- OCSPSigning - Signing OCSP responses

### Cert.ForClientAuthentication

`Chilkat 11.7.0 · objc · Cert · ForClientAuthentication · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL ForClientAuthentication;
```

`YES` if this certificate can be used for client authentication, otherwise `NO`.

### Cert.ForCodeSigning

`Chilkat 11.7.0 · objc · Cert · ForCodeSigning · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL ForCodeSigning;
```

`YES` if this certificate can be used for code signing, otherwise `NO`.

### Cert.ForSecureEmail

`Chilkat 11.7.0 · objc · Cert · ForSecureEmail · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL ForSecureEmail;
```

`YES` if this certificate can be used for sending secure email, otherwise `NO`.

### Cert.ForServerAuthentication

`Chilkat 11.7.0 · objc · Cert · ForServerAuthentication · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL ForServerAuthentication;
```

`YES` if this certificate can be used for server authentication, otherwise `NO`.

### Cert.ForTimeStamping

`Chilkat 11.7.0 · objc · Cert · ForTimeStamping · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL ForTimeStamping;
```

`YES` if this certificate can be used for time stamping, otherwise `NO`.

### Cert.IntendedKeyUsage

`Chilkat 11.7.0 · objc · Cert · IntendedKeyUsage · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSNumber *IntendedKeyUsage;
```

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

### Cert.IsRoot

`Chilkat 11.7.0 · objc · Cert · IsRoot · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL IsRoot;
```

`YES` if this is the root certificate, otherwise `NO`.

### Cert.IssuerC

`Chilkat 11.7.0 · objc · Cert · IssuerC · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerC;
```

The certificate issuer's country.

### Cert.IssuerCN

`Chilkat 11.7.0 · objc · Cert · IssuerCN · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerCN;
```

The certificate issuer's common name.

### Cert.IssuerDN

`Chilkat 11.7.0 · objc · Cert · IssuerDN · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerDN;
```

The issuer's full distinguished name.

### Cert.IssuerE

`Chilkat 11.7.0 · objc · Cert · IssuerE · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerE;
```

The certificate issuer's email address.

### Cert.IssuerL

`Chilkat 11.7.0 · objc · Cert · IssuerL · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerL;
```

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

### Cert.IssuerO

`Chilkat 11.7.0 · objc · Cert · IssuerO · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerO;
```

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

### Cert.IssuerOU

`Chilkat 11.7.0 · objc · Cert · IssuerOU · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerOU;
```

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

### Cert.IssuerS

`Chilkat 11.7.0 · objc · Cert · IssuerS · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *IssuerS;
```

The certificate issuer's state or province.

### Cert.OcspUrl

`Chilkat 11.7.0 · objc · Cert · OcspUrl · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *OcspUrl;
```

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.)

### Cert.PrivateKeyExportable

`Chilkat 11.7.0 · objc · Cert · PrivateKeyExportable · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL PrivateKeyExportable;
```

(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.

### Cert.Revoked

`Chilkat 11.7.0 · objc · Cert · Revoked · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL Revoked;
```

**Deprecated:** This property does not check the revocation status of the certificate, and always returns `NO`. Do not use it to decide whether a certificate is revoked.

To check whether a certificate has been revoked, call `CheckRevoked` (Windows only), which returns 1 (revoked), 0 (not revoked), or -1 (unable to check). Applications on any operating system can also send an OCSP request to the certificate's `OcspUrl`, if the certificate has one.

(A property cannot do this work because checking revocation can require contacting a CRL distribution point or an OCSP responder over the network, which can take a long time. In some programming languages, properties are evaluated at design time in the IDE.)

**Note:** Chilkat does not check certificate revocation status during the TLS handshake. Settings such as `RequireSslCertVerify` verify signatures, expiration, and the chain to a trusted root, but not revocation. To reject a revoked server certificate, the application must check it after connecting.

### Cert.Rfc822Name

`Chilkat 11.7.0 · objc · Cert · Rfc822Name · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *Rfc822Name;
```

The RFC822 name of the certificate. (The RFC822 name is one part of the Subject Alternative Name extension of a certificate, if it exists. It is often the only part of the SAN.)

If the certificate contains a list of RFC822 names then this property will return the comma separated list of names.

Starting in Chilkat v9.5.0.85, to get the complete Subject Alternative Name extension as XML, use the SubjectAlternativeName property.

### Cert.SelfSigned

`Chilkat 11.7.0 · objc · Cert · SelfSigned · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL SelfSigned;
```

`YES` if this is a self-signed certificate, otherwise `NO`.

### Cert.SerialDecimal

`Chilkat 11.7.0 · objc · Cert · SerialDecimal · property · read-only · since 9.5.0.75`

```objectivec
@property (nonatomic, readonly, copy) NSString *SerialDecimal;
```

The certificate's serial number as a decimal string.

### Cert.SerialNumber

`Chilkat 11.7.0 · objc · Cert · SerialNumber · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SerialNumber;
```

The certificate's serial number as a hexidecimal string.

### Cert.Sha1Thumbprint

`Chilkat 11.7.0 · objc · Cert · Sha1Thumbprint · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *Sha1Thumbprint;
```

Hexidecimal string of the SHA-1 thumbprint for the certificate. (This is the SHA1 hash of the binary DER representation of the entire X.509 certificate.)

### Cert.SignatureVerified

`Chilkat 11.7.0 · objc · Cert · SignatureVerified · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL SignatureVerified;
```

Returns `YES` if the certificate and all certificates in the chain of authority have valid signatures, otherwise returns `NO`.

### Cert.SmartCardFailReason

`Chilkat 11.7.0 · objc · Cert · SmartCardFailReason · property · read-only · since 10.1.0`

```objectivec
@property (nonatomic, readonly, copy) NSNumber *SmartCardFailReason;
```

Set after calling LoadFromSmartcard. Possible values are:

- 0 - No failure. The call to LoadFromSmartcard was successful.
- 1 - No smartcard or USB token was detected.
- 2 - The SmartCardPin was provided and the PIN login failed. (Note: Chilkat only PIN authenticates if PKCS11 was the chosen means for communicating with the smartcard.)
- 3 - The certificate matching the specified criteria was not found.
- 99 - Some other undefined failure. Consult the LastErrorText for more information.

### Cert.SmartCardPin

`Chilkat 11.7.0 · objc · Cert · SmartCardPin · property · read/write · since 9.5.0.75`

```objectivec
@property (nonatomic, copy) NSString *SmartCardPin;
```

Can be set to the PIN value for a certificate / private key stored on a smart card.

### Cert.SubjectAlternativeName

`Chilkat 11.7.0 · objc · Cert · SubjectAlternativeName · property · read-only · since 9.5.0.85`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectAlternativeName;
```

The subject alternative name (SAN) name of the certificate returned as XML. See the examples linked below.

### Cert.SubjectC

`Chilkat 11.7.0 · objc · Cert · SubjectC · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectC;
```

The certificate subject's country.

### Cert.SubjectCN

`Chilkat 11.7.0 · objc · Cert · SubjectCN · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectCN;
```

The certificate subject's common name.

### Cert.SubjectDN

`Chilkat 11.7.0 · objc · Cert · SubjectDN · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectDN;
```

The certificate subject's full distinguished name.

### Cert.SubjectE

`Chilkat 11.7.0 · objc · Cert · SubjectE · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectE;
```

The certificate subject's email address.

### Cert.SubjectKeyId

`Chilkat 11.7.0 · objc · Cert · SubjectKeyId · property · read-only · since 9.5.0.40`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectKeyId;
```

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.

### Cert.SubjectL

`Chilkat 11.7.0 · objc · Cert · SubjectL · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectL;
```

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

### Cert.SubjectO

`Chilkat 11.7.0 · objc · Cert · SubjectO · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectO;
```

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

### Cert.SubjectOU

`Chilkat 11.7.0 · objc · Cert · SubjectOU · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectOU;
```

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

### Cert.SubjectS

`Chilkat 11.7.0 · objc · Cert · SubjectS · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *SubjectS;
```

The certificate subject's state or province.

### Cert.TrustedRoot

`Chilkat 11.7.0 · objc · Cert · TrustedRoot · property · read-only`

```objectivec
@property (nonatomic, readonly) BOOL TrustedRoot;
```

Returns `YES` if the certificate has a trusted root authority, otherwise returns `NO`.

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 `NO` 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 `YES`, 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.

### Cert.UncommonOptions

`Chilkat 11.7.0 · objc · Cert · UncommonOptions · property · read/write · since 9.5.0.87`

```objectivec
@property (nonatomic, copy) NSString *UncommonOptions;
```

This is a catch-all property to be used for uncommon needs. This property defaults to the empty string, and should typically remain empty. Possible comma separated keywords can include:

- `CheckRevokedCacheOnly`: Added in `v11.2.0`. In the `CheckRevoked` method, prevents network access and only checks the cached revocation information on the local computer.

### Cert.ValidFromStr

`Chilkat 11.7.0 · objc · Cert · ValidFromStr · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *ValidFromStr;
```

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

### Cert.ValidToStr

`Chilkat 11.7.0 · objc · Cert · ValidToStr · property · read-only`

```objectivec
@property (nonatomic, readonly, copy) NSString *ValidToStr;
```

The date (in RFC822 string format) that this certificate expires. It is a GMT/UTC date that is returned.

## Methods

### Cert.BuildCertChain

`Chilkat 11.7.0 · objc · Cert · BuildCertChain · method · since 11.0.0`

```objectivec
- (BOOL)BuildCertChain:(CkoCertChain *)certChain;
```

Builds the certificate chain in `certChain` 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: Returns `YES` even if certificate chain is not completed to the root. 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. Chilkat searches certificate stores in the following order. See [System Store Locations](https://docs.microsoft.com/en-us/windows/desktop/seccrypto/system-store-locations) for more information.

1. Current-User `CA` Certificate Store
2. Local-Machine `CA` Certificate Store
3. Current-User `Root` Certificate Store
4. Local-Machine `Root` Certificate Store
5. Current-User `MY` Certificate Store
6. Local-Machine `MY` Certificate Store
7. Current-User `ADDRESSBOOK` Certificate Store (if it exists)
8. Local-Machine `ADDRESSBOOK` Certificate Store (if it exists)

Returns YES for success, NO for failure.

### Cert.CheckSmartCardPin

`Chilkat 11.7.0 · objc · Cert · CheckSmartCardPin · method · since 9.5.0.77`

```objectivec
- (NSNumber *)CheckSmartCardPin;
```

Verifies that the SmartCardPin property setting is correct. Returns 1 if correct, 0 if incorrect, and -1 if unable to check because the underlying CSP does not support the functionality.

### Cert.ExportCertDer

`Chilkat 11.7.0 · objc · Cert · ExportCertDer · method`

```objectivec
- (NSData *)ExportCertDer;
```

Exports the digital certificate to ASN.1 DER format.

Returns `nil` on failure

### Cert.ExportCertDerBd

`Chilkat 11.7.0 · objc · Cert · ExportCertDerBd · method · since 9.5.0.70`

```objectivec
- (BOOL)ExportCertDerBd:(CkoBinData *)cerData;
```

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

Returns YES for success, NO for failure.

### Cert.ExportCertDerFile

`Chilkat 11.7.0 · objc · Cert · ExportCertDerFile · method`

```objectivec
- (BOOL)ExportCertDerFile:(NSString *)path;
```

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

Returns YES for success, NO for failure.

### Cert.ExportCertPem

`Chilkat 11.7.0 · objc · Cert · ExportCertPem · method`

```objectivec
- (NSString *)ExportCertPem;
```

Exports the digital certificate to an unencrypted PEM formatted string.

Returns `nil` on failure

### Cert.ExportCertPemFile

`Chilkat 11.7.0 · objc · Cert · ExportCertPemFile · method`

```objectivec
- (BOOL)ExportCertPemFile:(NSString *)path;
```

Exports the digital certificate to an unencrypted PEM formatted file.

Returns YES for success, NO for failure.

### Cert.ExportCertXml

`Chilkat 11.7.0 · objc · Cert · ExportCertXml · method`

```objectivec
- (NSString *)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 `nil` on failure

### Cert.ExportToPfxBd

`Chilkat 11.7.0 · objc · Cert · ExportToPfxBd · method · since 9.5.0.70`

```objectivec
- (BOOL)ExportToPfxBd:(NSString *)password 
    includeCertChain:(BOOL)includeCertChain 
    pfxData:(CkoBinData *)pfxData;
```

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 `YES`, then the certificates in the chain of authority are also included in the PFX.

Returns YES for success, NO for failure.

### Cert.ExportToPfxData

`Chilkat 11.7.0 · objc · Cert · ExportToPfxData · method · since 9.5.0.31`

```objectivec
- (NSData *)ExportToPfxData:(NSString *)password 
    includeCertChain:(BOOL)includeCertChain;
```

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 `YES`, then the certificates in the chain of authority are also included in the PFX.

Returns `nil` on failure

### Cert.ExportToPfxFile

`Chilkat 11.7.0 · objc · Cert · ExportToPfxFile · method`

```objectivec
- (BOOL)ExportToPfxFile:(NSString *)pfxFilename 
    pfxPassword:(NSString *)pfxPassword 
    bIncludeCertChain:(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 `YES`, then the certificates in the chain of authority are also included in the PFX output file.

Returns YES for success, NO for failure.

### Cert.FindIssuer

`Chilkat 11.7.0 · objc · Cert · FindIssuer · method`

```objectivec
- (CkoCert *)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 `nil` on failure

### Cert.GetEncoded

`Chilkat 11.7.0 · objc · Cert · GetEncoded · method`

```objectivec
- (NSString *)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 `nil` on failure

### Cert.GetExtensionAsText

`Chilkat 11.7.0 · objc · Cert · GetExtensionAsText · method · since 9.5.0.89`

```objectivec
- (NSString *)GetExtensionAsText:(NSString *)oid;
```

Returns the certificate extension data as a string. This method should only be called for those extensions with text values NOT stored as binary ASN.1. In most cases, applications should call GetExtensionAsXml because most extensions contain ASN.1 values that need to be decoded..

Returns `nil` on failure

### Cert.GetExtensionAsXml

`Chilkat 11.7.0 · objc · Cert · GetExtensionAsXml · method · since 9.5.0.49`

```objectivec
- (NSString *)GetExtensionAsXml:(NSString *)oid;
```

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 `nil` on failure

### Cert.GetExtensionBd

`Chilkat 11.7.0 · objc · Cert · GetExtensionBd · method · since 9.5.0.96`

```objectivec
- (BOOL)GetExtensionBd:(NSString *)oid 
    bd:(CkoBinData *)bd;
```

Returns the certificate extension data specified by `oid` in `bd`.

Returns YES for success, NO for failure.

### Cert.GetIssuer

`Chilkat 11.7.0 · objc · Cert · GetIssuer · method · since 11.0.0`

```objectivec
- (BOOL)GetIssuer:(CkoCert *)issuer;
```

Finds and returns the issuer certificate in `issuer`. 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 YES for success, NO for failure.

### Cert.GetPrivateKey

`Chilkat 11.7.0 · objc · Cert · GetPrivateKey · method · since 11.0.0`

```objectivec
- (BOOL)GetPrivateKey:(CkoPrivateKey *)privKey;
```

Loads the `privKey` with the certificate's private key, if it exists. Returns `NO` if the certificate has no associated private key.

Returns YES for success, NO for failure.

### Cert.GetPrivateKeyPem

`Chilkat 11.7.0 · objc · Cert · GetPrivateKeyPem · method`

```objectivec
- (NSString *)GetPrivateKeyPem;
```

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

Returns `nil` on failure

### Cert.GetPubKeyDer

`Chilkat 11.7.0 · objc · Cert · GetPubKeyDer · method · since 9.5.0.92`

```objectivec
- (BOOL)GetPubKeyDer:(BOOL)preferPkcs1 
    bd:(CkoBinData *)bd;
```

Loads the `bd` with the certificate's public key in ASN.1 DER format. If the key type (such as RSA) supports both PKCS1 and PKCS8 formats, then `preferPkcs1` selects which format to return.

Returns YES for success, NO for failure.

### Cert.GetPublicKey

`Chilkat 11.7.0 · objc · Cert · GetPublicKey · method · since 11.0.0`

```objectivec
- (BOOL)GetPublicKey:(CkoPublicKey *)pubKey;
```

Loads the `pubKey` with the certificate's public key.

Returns YES for success, NO for failure.

### Cert.GetSignature

`Chilkat 11.7.0 · objc · Cert · GetSignature · method · since 9.5.0.92`

```objectivec
- (BOOL)GetSignature:(CkoBinData *)bd;
```

Loads the `bd` with the certificate's signature.

Returns YES for success, NO for failure.

### Cert.GetSpkiFingerprint

`Chilkat 11.7.0 · objc · Cert · GetSpkiFingerprint · method · since 9.5.0.55`

```objectivec
- (NSString *)GetSpkiFingerprint:(NSString *)hashAlg 
    encoding:(NSString *)encoding;
```

**Full documentation for this method (same in every language):** [List of Chilkat Encoding Modes](https://www.chilkatsoft.com/ai-docs/v/11.7.0/articles/binary_encodings.md)

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 `nil` on failure

### Cert.GetSubjectPart

`Chilkat 11.7.0 · objc · Cert · GetSubjectPart · method · since 9.5.0.85`

```objectivec
- (NSString *)GetSubjectPart:(NSString *)partNameOrOid;
```

Returns a part of the certificate's subject by name or OID. The `partNameOrOid` can be a part name, such as `CN`, `O`, `OU`, `E`, `S`, `L`, `C`, or `SERIALNUMBER`, or it can be an OID such as `2.5.4.3`.

Returns `nil` on failure

### Cert.HashOf

`Chilkat 11.7.0 · objc · Cert · HashOf · method · since 9.5.0.75`

```objectivec
- (NSString *)HashOf:(NSString *)part 
    hashAlg:(NSString *)hashAlg 
    encoding:(NSString *)encoding;
```

Returns an encoded hash of a particular part of the certificate. The `part` may be one of the following:

- IssuerDN
- IssuerPublicKey
- SubjectDN
- SubjectPublicKey

The `hashAlg` is the name of the hash algorithm, such as `sha1`, `sha256`, `sha384`, `sha512`, `md5`, etc. The `encoding` is the format to return, such as `hex`, `base64`, etc.

Returns `nil` on failure

### Cert.HasPrivateKey

`Chilkat 11.7.0 · objc · Cert · HasPrivateKey · method`

```objectivec
- (BOOL)HasPrivateKey;
```

Returns `YES` if a private key associated with the certificate is available.

### Cert.IsEcdsa

`Chilkat 11.7.0 · objc · Cert · IsEcdsa · method · since 10.1.0`

```objectivec
- (BOOL)IsEcdsa;
```

Returns `YES` if certificate is ECDSA-based (i.e. has an ECDSA key).

### Cert.IsRsa

`Chilkat 11.7.0 · objc · Cert · IsRsa · method · since 10.1.0`

```objectivec
- (BOOL)IsRsa;
```

Returns `YES` if certificate is RSA-based (i.e. has an RSA key).

### Cert.LinkPkcs11

`Chilkat 11.7.0 · objc · Cert · LinkPkcs11 · method · since 9.5.0.96`

```objectivec
- (BOOL)LinkPkcs11:(CkoPkcs11 *)session;
```

Links to the certificate's private key located on an HSM (smart card, token, or cloud HSM). Once linked, the certificate can be used for signing where the signing occurs on the HSM. See the example below for more detailed information.

Returns YES for success, NO for failure.

### Cert.LoadByCommonName

`Chilkat 11.7.0 · objc · Cert · LoadByCommonName · method`

```objectivec
- (BOOL)LoadByCommonName:(NSString *)cn;
```

This method searches for a certificate with the specified common name (CN) on different operating systems. - On `Windows`, it searches the `Local Machine` and `Current User` certificate stores. - On `macOS` and `iOS`, it searches the Default and System `Keychains`. If the certificate is found, it is loaded and ready for use.

Note: Chilkat v10.0.0 or later is needed for Apple Keychain.

Returns YES for success, NO for failure.

### Cert.LoadByEmailAddress

`Chilkat 11.7.0 · objc · Cert · LoadByEmailAddress · method`

```objectivec
- (BOOL)LoadByEmailAddress:(NSString *)emailAddress;
```

This method searches for a certificate with the specified email address on different operating systems. - On `Windows`, it searches the `Local Machine` and `Current User` certificate stores. - On `macOS` and `iOS`, it searches the Default and System `Keychains`. If the certificate is found, it is loaded and ready for use.

Note: Chilkat v10.0.0 or later is needed for Apple Keychain.

Returns YES for success, NO for failure.

### Cert.LoadByIssuerAndSerialNumber

`Chilkat 11.7.0 · objc · Cert · LoadByIssuerAndSerialNumber · method`

```objectivec
- (BOOL)LoadByIssuerAndSerialNumber:(NSString *)issuerCN 
    serialNumber:(NSString *)serialNumber;
```

This method searches for a certificate with the specified issuer common name (`issuerCN`) and serial number (`serialNumber`) on different operating systems. - On `Windows`, it searches the `Local Machine` and `Current User` certificate stores. - On `macOS` and `iOS`, it searches the Default and System `Keychains`. If the certificate is found, it is loaded and ready for use.

Note: Chilkat v10.0.0 or later is needed for Apple Keychain.

Returns YES for success, NO for failure.

### Cert.LoadBySubjectOid

`Chilkat 11.7.0 · objc · Cert · LoadBySubjectOid · method · since 9.5.0.85`

```objectivec
- (BOOL)LoadBySubjectOid:(NSString *)oid 
    value:(NSString *)value;
```

**Full documentation for this method (same in every language):** [Common Certificate Subject OIDs](https://www.chilkatsoft.com/ai-docs/v/11.7.0/articles/cert_subject_oids.md)

This method searches for a certificate containing a subject part matching the `oid` and `value`. On `Windows`, it searches the `Local Machine` and `Current User` certificate stores. - On `macOS` and `iOS`, it searches the Default and System `Keychains`. If the certificate is found, it is loaded and ready for use.

Note: Chilkat v10.0.0 or later is needed for Apple Keychain.

Returns YES for success, NO for failure.

### Cert.LoadByThumbprint

`Chilkat 11.7.0 · objc · Cert · LoadByThumbprint · method · since 9.5.0.83`

```objectivec
- (BOOL)LoadByThumbprint:(NSString *)thumbprint 
    encoding:(NSString *)encoding;
```

This method searches for a certificate with the specified `thumbprint`. The `thumbprint` is passed as a string using the encoding specified by `encoding` (such as `base64`, `hex`, etc.).

On `Windows`, it searches the `Local Machine` and `Current User` certificate stores. - On `macOS` and `iOS`, it searches the Default and System `Keychains`. If the certificate is found, it is loaded and ready for use.

Note: Chilkat v10.0.0 or later is needed for Apple Keychain.

Returns YES for success, NO for failure.

### Cert.LoadFromBase64

`Chilkat 11.7.0 · objc · Cert · LoadFromBase64 · method`

```objectivec
- (BOOL)LoadFromBase64:(NSString *)encodedCert;
```

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

Returns YES for success, NO for failure.

### Cert.LoadFromBd

`Chilkat 11.7.0 · objc · Cert · LoadFromBd · method · since 9.5.0.70`

```objectivec
- (BOOL)LoadFromBd:(CkoBinData *)certBytes;
```

Loads an X.509 certificate from data contained in `certBytes`.

**Note:** The `certBytes` may contain the certificate in any format. It can be binary DER (ASN.1), PEM, Base64, etc. Chilkat will automatically detect the format.

Returns YES for success, NO for failure.

### Cert.LoadFromBinary

`Chilkat 11.7.0 · objc · Cert · LoadFromBinary · method`

```objectivec
- (BOOL)LoadFromBinary:(NSData *)data;
```

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

**Note:** The `data` may contain the certificate in any format. It can be binary DER (ASN.1), PEM, Base64, etc. Chilkat will automatically detect the format.

Returns YES for success, NO for failure.

### Cert.LoadFromFile

`Chilkat 11.7.0 · objc · Cert · LoadFromFile · method`

```objectivec
- (BOOL)LoadFromFile:(NSString *)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 YES for success, NO for failure.

### Cert.LoadFromSmartcard

`Chilkat 11.7.0 · objc · Cert · LoadFromSmartcard · method · since 9.5.0.77`

```objectivec
- (BOOL)LoadFromSmartcard:(NSString *)certSpec;
```

**Important:** It's important to set the SmartCardPin property **before** calling this method.

Loads a certificate and its associated private key (if available) from a connected USB token or smart card. This function works on Windows, Linux, MacOS, iOS, and Alpine Linux. If multiple USB tokens and/or smartcards are connected to the system, then each will be searched and the first matching certificate will be loaded.

The `certSpec` can have the following formats and values:

- **Empty String**: Passing the empty string is the most common way to call this function. Pass the empty string when only one HSM (USB token or smart card) is connected to the system, and it contains only one certificate with a private key. The HSM can contain other certificates, but Chilkat will automatically choose and load the certificate that has the associated private key also located on the HSM.
- **cn=\<cert subject common name>**: Finds and loads the certificate having the specified subject common name (CN).
- **subjectdn_withtags=\<distinguished name with tags>**: Finds and loads the certificate having the specified DN with tags. For example, subjectdn_withtags=C=US, O=Example Corporation, OU=IT Department, CN=www.example.com
- **subjectdn=\<distinguished name without tags>**: Finds and loads the certificate having the specified DN without tags. For example, subjectdn=US, California, San Francisco, Example Corp, Engineering, www.example.com, support@example.com
- **issuercn=\<subject hex serial:issuer common name>**: Finds and loads the certificate having the specified hex serial number and an issuer with the specified common name. For example, `01020304: Let's Encrypt Authority X1`
- **serial=\<hex serial number>**: Finds and loads the certificate having the specified hexidecimal serial number.
- **thumbprint=\<hex SHA1 thumbprint>**: Finds and loads the certificate having the specified hexidecimal SHA1 thumbprint.
- **policyoid=\<certificate policy OID>**: Finds and loads the certificate having a policy OID equal to the specified value, such as 2.16.840.1.101.2.1.11.39.
- **o=\<subject organization>**: Finds and loads the certificate having the `O` subject part equal to the specified value.
- **c=\<subject country>**: Finds and loads the certificate having the `C` subject part equal to the specified value.
- **l=\<subject locality>**: Finds and loads the certificate having the `L` subject part equal to the specified value.
- **ou=\<subject organizational unit>**: Finds and loads the certificate having the `OU` subject part equal to the specified value.
- **st=\<subject state>**: Finds and loads the certificate having the `ST` subject part equal to the specified value.
- **e=\<subject email>**: Finds and loads the certificate having the `E` subject part equal to the specified value.

On Windows systems, `certSpec` can specify a CSP (Cryptographic Service Provider) name, such as `YubiHSM Key Storage Provider.` This option is retained for legacy support, as Chilkat initially handled USB tokens and smartcards only on Windows via CSPs. Chilkat now supports HSMs across multiple platforms (Windows, Linux, macOS, iOS, Alpine Linux) and uses various methods to communicate with HSMs, including PKCS11, macOS Keychain services, Windows ScMinidriver, MsCNG, and legacy Windows CryptoAPI. Chilkat automatically detects the HSM make/model and selects the optimal communication method.

Some possible CSP values are:

- Microsoft Smart Card Key Storage Provider
- Microsoft Base Smart Card Crypto Provider
- Bit4id Universal Middleware Provider
- YubiHSM Key Storage Provider (starting in v9.5.0.83)
- SafeSign Standard Cryptographic Service Provider
- SafeSign Standard RSA and AES Cryptographic Service Provider
- eToken Base Cryptographic Provider
- cryptoCertum3 CSP
- FTSafe ePass1000 RSA Cryptographic Service Provider
- SecureStoreCSP
- EnterSafe ePass2003 CSP v2.0
- Gemalto Classic Card CSP
- PROXKey CSP India V1.0
- PROXKey CSP India V2.0
- TRUST KEY CSP V1.0
- Watchdata Brazil CSP V1.0
- Luna Cryptographic Services for Microsoft Windows
- Luna SChannel Cryptographic Services for Microsoft Windows
- Safenet RSA Full Cryptographic Provider
- nCipher Enhanced Cryptographic Provider
- MySmartLogon NFC CSP
- NFC Connector Enterprise
- ActivClient Cryptographic Service Provider
- EnterSafe ePass2003 CSP v1.0
- Oberthur Card Systems Cryptographic Provider
- Athena ASECard Crypto CSP
- many others...

Returns YES for success, NO for failure.

### Cert.LoadPem

`Chilkat 11.7.0 · objc · Cert · LoadPem · method · since 9.5.0.49`

```objectivec
- (BOOL)LoadPem:(NSString *)strPem;
```

Loads the certificate from a PEM string.

Returns YES for success, NO for failure.

### Cert.LoadPfxBd

`Chilkat 11.7.0 · objc · Cert · LoadPfxBd · method · since 9.5.0.70`

```objectivec
- (BOOL)LoadPfxBd:(CkoBinData *)pfxData 
    password:(NSString *)password;
```

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 YES for success, NO for failure.

### Cert.LoadPfxData

`Chilkat 11.7.0 · objc · Cert · LoadPfxData · method`

```objectivec
- (BOOL)LoadPfxData:(NSData *)pfxData 
    password:(NSString *)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 YES for success, NO for failure.

### Cert.LoadPfxFile

`Chilkat 11.7.0 · objc · Cert · LoadPfxFile · method`

```objectivec
- (BOOL)LoadPfxFile:(NSString *)path 
    password:(NSString *)password;
```

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

Returns YES for success, NO for failure.

### Cert.LoadTaskResult

`Chilkat 11.7.0 · objc · Cert · LoadTaskResult · method · since 9.5.0.52`

```objectivec
- (BOOL)LoadTaskResult:(CkoTask *)task;
```

Loads the certificate from a completed asynchronous task.

Returns YES for success, NO for failure.

### Cert.PemFileToDerFile

`Chilkat 11.7.0 · objc · Cert · PemFileToDerFile · method`

```objectivec
- (BOOL)PemFileToDerFile:(NSString *)fromPath 
    toPath:(NSString *)toPath;
```

Converts a PEM file to a DER file.

Returns YES for success, NO for failure.

### Cert.SaveToFile

`Chilkat 11.7.0 · objc · Cert · SaveToFile · method`

```objectivec
- (BOOL)SaveToFile:(NSString *)path;
```

Saves a certificate object to a .cer file.

Returns YES for success, NO for failure.

### Cert.SetCloudSigner

`Chilkat 11.7.0 · objc · Cert · SetCloudSigner · method · since 9.5.0.96`

```objectivec
- (BOOL)SetCloudSigner:(CkoJsonObject *)json;
```

Provides information for a cloud signing service to do the signing via a remote signing server. Current supported services are AWS KMS, Azure Key Vault, and ARSS (Aruba Remote Signing Service). See the examples below.

Returns YES for success, NO for failure.

Async variant: `SetCloudSignerAsync` — same arguments, returns a `Task` (see Async variants below).

### Cert.SetFromEncoded

`Chilkat 11.7.0 · objc · Cert · SetFromEncoded · method`

```objectivec
- (BOOL)SetFromEncoded:(NSString *)encodedCert;
```

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

Returns YES for success, NO for failure.

### Cert.SetPrivateKey

`Chilkat 11.7.0 · objc · Cert · SetPrivateKey · method`

```objectivec
- (BOOL)SetPrivateKey:(CkoPrivateKey *)privKey;
```

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

Returns YES for success, NO for failure.

### Cert.SetPrivateKeyPem

`Chilkat 11.7.0 · objc · Cert · SetPrivateKeyPem · method`

```objectivec
- (BOOL)SetPrivateKeyPem:(NSString *)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 YES for success, NO for failure.

### Cert.Unload

`Chilkat 11.7.0 · objc · Cert · Unload · method · since 11.0.0`

```objectivec
- (BOOL)Unload;
```

Unload the certificate, which could mean closing a PKCS11 session if the certificate was loaded from a smart card.

Returns YES for success, NO for failure.

### Cert.UploadToCloud

`Chilkat 11.7.0 · objc · Cert · UploadToCloud · method · since 9.5.0.96`

```objectivec
- (BOOL)UploadToCloud:(CkoJsonObject *)jsonIn 
    jsonOut:(CkoJsonObject *)jsonOut;
```

This is an open-ended method to accomodate uploading the private key to a cloud service, such as AWS KMS, or Azure Key Vault. For details, see the examples below.

Returns YES for success, NO for failure.

Async variant: `UploadToCloudAsync` — same arguments, returns a `Task` (see Async variants below).

### Cert.UseCertVault

`Chilkat 11.7.0 · objc · Cert · UseCertVault · method · since 9.5.0.40`

```objectivec
- (BOOL)UseCertVault:(CkoXmlCertVault *)vault;
```

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 YES for success, NO for failure.

### Cert.VerifySignature

`Chilkat 11.7.0 · objc · Cert · VerifySignature · method · since 9.5.0.40`

```objectivec
- (BOOL)VerifySignature;
```

Verifies the certificate signature, as well as the signatures of all certificates in the chain of authentication to the trusted root. Returns `YES` if all signatures are verified to the trusted root. Otherwise returns `NO`.

### Cert.X509PKIPathv1

`Chilkat 11.7.0 · objc · Cert · X509PKIPathv1 · method · since 9.5.0.77`

```objectivec
- (NSString *)X509PKIPathv1;
```

Returns the base64 representation of an X509PKIPathv1 containing just the calling certificate. This is typically used in an X.509 Binary Security Token. It is a PKIPath that contains an ordered list of X.509 public certificates packaged in a PKIPath. The X509PKIPathv1 token type may be used to represent a certificate path. (This is sometimes used in XAdES signatures.)

Returns `nil` on failure

## Events and callbacks

To receive events, define your own class that inherits from CkoBaseProgress and override just the methods you want to handle. The base class provides an empty implementation of every method, so anything you don't override is simply ignored.

Then create an instance of your class and pass it to the object's setEventCallbackObject: method. From that point on, the object calls your methods as the work proceeds.

**For example:**

```objectivec
  CkoCert *cert = [[CkoCert alloc] init];

  MyCertProgress *callbackObj = [[MyCertProgress alloc] init];

  [cert setEventCallbackObject:callbackObj];
```

**MyCertProgress interface example:**

```objectivec
#import "CkoBaseProgress.h"

@interface MyCertProgress : CkoBaseProgress {

}

    - (id)init;
    - (void)dealloc;
    - (void)dispose;

    - (void)AbortCheck:(BOOL *)abort;
    - (void)PercentDone:(NSNumber *)pctDone 
        abort:(BOOL *)abort;
    - (void)ProgressInfo:(NSString *)name 
        value:(NSString *)value;
    - (void)TaskCompleted:(CkoTask *)task;
@end
```

### Cert.AbortCheck (event)

`Chilkat 11.7.0 · objc · Cert · AbortCheck · event`

```objectivec
- (void)AbortCheck:(BOOL *)abort;
```

Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the `HeartbeatMs` property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.

### Cert.PercentDone (event)

`Chilkat 11.7.0 · objc · Cert · PercentDone · event`

```objectivec
- (void)PercentDone:(NSNumber *)pctDone 
    abort:(BOOL *)abort;
```

This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The `pctDone` argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have `pctDone` equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).

The PercentDone callback also acts as an `AbortCheck` event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.

To abort the operation, set the `abort` output argument to `YES`. This will cause the method to terminate and return a failure status or corresponding failure value.

### Cert.ProgressInfo (event)

`Chilkat 11.7.0 · objc · Cert · ProgressInfo · event`

```objectivec
- (void)ProgressInfo:(NSString *)name 
    value:(NSString *)value;
```

This event callback provides `tag name`/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.

Note: Some Chilkat methods don't fire any ProgressInfo events.

### Cert.TaskCompleted (event)

`Chilkat 11.7.0 · objc · Cert · TaskCompleted · event`

```objectivec
- (void)TaskCompleted:(CkoTask *)task;
```

Called from the background thread when an asynchronous task completes.

## Async variants

Each returns a `Task` instead of the result and takes the same arguments as the synchronous method; run the task, wait for `Finished`, then read the result from the task. No new Async methods are added from 11.7.0 on.

```objectivec
- (CkoTask *)SetCloudSignerAsync:(CkoJsonObject *)json;
- (CkoTask *)UploadToCloudAsync:(CkoJsonObject *)jsonIn 
    jsonOut:(CkoJsonObject *)jsonOut;
```

## Deprecated members — do not use in new code

| Member | Kind | Deprecated in | Use instead |
|---|---|---|---|
| `ExportPrivateKey` | method | before 11.6.1 | — |
| `ExportPublicKey` | method | before 11.6.1 | — |
| `GetCertChain` | method | before 11.6.1 | `BuildCertChain` |
| `GetValidFromDt` | method | before 11.6.1 | — |
| `GetValidToDt` | method | before 11.6.1 | — |

## Related classes

[`BinData`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/BinData.md), [`CertChain`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/CertChain.md), [`JsonObject`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/JsonObject.md), [`Pkcs11`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/Pkcs11.md), [`PrivateKey`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/PrivateKey.md), [`PublicKey`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/PublicKey.md), [`Task`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/Task.md), [`XmlCertVault`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/objc/classes/XmlCertVault.md)