--- product: Chilkat product_version: 11.7.0 language: csharp language_label: C# class: CertStore license: free deprecated: false reference_html: https://www.chilkatsoft.com/refdoc/csCertStoreRef.html --- # Chilkat CertStore — C# — v11.7.0 > Chilkat 11.7.0 · language=csharp · class=CertStore > Other versions: replace `11.7.0` in this URL. Other languages: `https://www.chilkatsoft.com/ai-docs/v/11.7.0//classes/CertStore.md`. > Language-wide rules (install, unlock, error model, strings/bytes): `https://www.chilkatsoft.com/ai-docs/v/11.7.0/csharp/guide.md`. ## Purpose **Open, search, manage, and use certificate collections from many sources.** `Chilkat.CertStore` is the Chilkat class for working with collections of X.509 certificates. It can open and manage certificates from system stores, Apple Keychain, Windows registry or file stores, memory stores, PEM files, PFX/P12 files, and smart card or USB token devices. It supports loading, searching, iterating, adding, removing, and closing certificate stores, with platform-specific behavior for Windows and Apple Keychain. **Open certificate stores** Access certificates from Windows certificate stores, Apple Keychain, files, memory stores, PEM bundles, PFX/P12 files, and hardware tokens. **Search and retrieve certs** Find certificates by subject, issuer, serial number, thumbprint, email, private-key availability, or other identifying information. **Iterate collections** Enumerate certificates in a store and retrieve each certificate as a `Chilkat.Cert` object for inspection or use. **Add and remove certificates** Add certificates to writable stores, remove certificates where supported, and manage store contents from application code. **Private-key backed certs** Work with certificates that have associated private keys from PFX/P12, operating-system stores, smart cards, USB tokens, or other providers. **Use across Chilkat** Pass retrieved certificates to other Chilkat classes for TLS client authentication, S/MIME, signing, encryption, decryption, and verification. **Common pattern:** Open the appropriate certificate store, search or iterate to find the needed certificate, retrieve it as a `Chilkat.Cert`, and then pass that certificate to the Chilkat class that needs it. Use certificate stores when the application should select from existing system, file-based, keychain, or hardware-backed certificates. For an extended overview, see [CertStore Class Overview](https://www.chilkatsoft.com/certstore_class_overview.asp). ## Object creation, unlocking and error handling **Object Creation** ```csharp Chilkat.CertStore obj = new Chilkat.CertStore(); ``` 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 C#. Minimal complete program: ```csharp // Required once per process. Any string unlocks a 30-day trial; use your purchased code in production. Chilkat.Global glob = new Chilkat.Global(); if (!glob.UnlockBundle("Anything for 30-day trial")) { Console.WriteLine(glob.LastErrorText); return; } Chilkat.CertStore certStore = new Chilkat.CertStore(); bool success = certStore.CreateFileStore(""); if (!success) { Console.WriteLine(certStore.LastErrorText); // full diagnostic of what went wrong return; } ``` 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` | `public string DebugLogFilePath {get; set; }` | 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` | `public string LastErrorHtml {get; }` | read-only | Provides HTML-formatted information about the last called method or property. | | `LastErrorText` | `public string LastErrorText {get; }` | read-only | Provides plain text information about the last called method or property. | | `LastErrorXml` | `public string LastErrorXml {get; }` | read-only | Provides XML-formatted information about the last called method or property. | | `LastMethodSuccess` | `public bool LastMethodSuccess {get; set; }` | read/write | Indicates the success or failure of the most recent method call: `true` means success, `false` means failure. | | `VerboseLogging` | `public bool VerboseLogging {get; set; }` | read/write | If set to `true`, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. | | `Version` | `public string Version {get; }` | read-only | Version of the component/library, such as "10.1.0" | ## Member index | Member | Kind | Signature | |---|---|---| | `AvoidWindowsPkAccess` | property, read/write | `public bool AvoidWindowsPkAccess {get; set; }` | | `NumCertificates` | property, read-only | `public int NumCertificates {get; }` | | `SmartCardPin` | property, read/write | `public string SmartCardPin {get; set; }` | | `UncommonOptions` | property, read/write | `public string UncommonOptions {get; set; }` | | `AddCertificate` | method | `public bool AddCertificate(Cert cert);` | | `CloseCertStore` | method | `public bool CloseCertStore();` | | `CreateFileStore` | method | `public bool CreateFileStore(string filename);` | | `CreateMemoryStore` | method | `public bool CreateMemoryStore();` | | `CreateRegistryStore` | method | `public bool CreateRegistryStore(string regRoot, string regPath);` | | `FindCert` | method | `public bool FindCert(JsonObject json, Cert cert);` | | `GetCert` | method | `public bool GetCert(int index, Cert cert);` | | `LoadPemFile` | method | `public bool LoadPemFile(string pemPath);` | | `LoadPemStr` | method | `public bool LoadPemStr(string pemString);` | | `LoadPfxBd` | method | `public bool LoadPfxBd(BinData bd, string password);` | | `LoadPfxFile` | method | `public bool LoadPfxFile(string pfxFilename, string password);` | | `OpenCurrentUserStore` | method | `public bool OpenCurrentUserStore(bool bReadOnly);` | | `OpenFileStore` | method | `public bool OpenFileStore(string filename, bool bReadOnly);` | | `OpenLocalSystemStore` | method | `public bool OpenLocalSystemStore(bool bReadOnly);` | | `OpenOutlookStore` | method | `public bool OpenOutlookStore(bool bReadOnly);` | | `OpenRegistryStore` | method | `public bool OpenRegistryStore(string regRoot, string regPath, bool bReadOnly);` | | `OpenSmartcard` | method | `public bool OpenSmartcard(string csp);` | | `OpenWindowsStore` | method | `public bool OpenWindowsStore(string storeLocation, string storeName, bool bReadOnly);` | | `RemoveCertificate` | method | `public bool RemoveCertificate(Cert cert);` | ## Properties ### CertStore.AvoidWindowsPkAccess `Chilkat 11.7.0 · csharp · CertStore · AvoidWindowsPkAccess · property · read/write` ```csharp 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`. ### CertStore.NumCertificates `Chilkat 11.7.0 · csharp · CertStore · NumCertificates · property · read-only` ```csharp public int NumCertificates {get; } ``` The number of certificates held in the certificate store. ### CertStore.SmartCardPin `Chilkat 11.7.0 · csharp · CertStore · SmartCardPin · property · read/write · since 9.5.0.86` ```csharp public string SmartCardPin {get; set; } ``` Can be set to the PIN value for a certificate / private key stored on a smart card. ### CertStore.UncommonOptions `Chilkat 11.7.0 · csharp · CertStore · UncommonOptions · property · read/write · since 9.5.0.87` ```csharp public string UncommonOptions {get; set; } ``` This is a catch-all property to be used for uncommon needs. This property defaults to the empty string, and should typically remain empty. ## Methods ### CertStore.AddCertificate `Chilkat 11.7.0 · csharp · CertStore · AddCertificate · method` ```csharp public bool AddCertificate(Cert cert); ``` On Windows, this updates or adds `cert` to the open Windows certificate store. Note: This imports the certificate without the private key. The `Chilkat.Pfx.ImportToWindows` method must be called to import a certificate with a private key. Beginning with Chilkat v10.0.0, on macOS and iOS, this adds the certificate, **including any private keys** and intermediate CA certificates, to the Apple Keychain. Returns true for success, false for failure. ### CertStore.CloseCertStore `Chilkat 11.7.0 · csharp · CertStore · CloseCertStore · method · since 9.5.0.94` ```csharp public bool CloseCertStore(); ``` This method closes any open certificate stores, removes all certificates from the object, and sets the NumCertificates property back to 0. Returns true for success, false for failure. ### CertStore.CreateFileStore `Chilkat 11.7.0 · csharp · CertStore · CreateFileStore · method` ```csharp public bool CreateFileStore(string filename); ``` This method, **available only on Microsoft Windows**, creates a new file-based certificate store. You can save certificates to this store by using the AddCertificate function. Internally, the Microsoft function CertOpenStore is called with the provider type CERT_STORE_PROV_FILE and the flag CERT_STORE_CREATE_NEW_FLAG, to create a new, empty certificate store that is backed by a file. Returns true for success, false for failure. ### CertStore.CreateMemoryStore `Chilkat 11.7.0 · csharp · CertStore · CreateMemoryStore · method` ```csharp public bool CreateMemoryStore(); ``` This method, **available only on Microsoft Windows**, creates an in-memory certificate store. Certificates may be added by calling AddCertificate. Internally, the Microsoft function CertOpenStore is called with the provider type CERT_STORE_PROV_MEMORY to create a new in-memory certificate store. This store acts as a temporary container for managing certificates during runtime. The store exists only in memory and is not backed by a file or persistent storage. Certificates can be added, retrieved, or removed, but the store is lost when the application ends unless explicitly saved elsewhere. Returns true for success, false for failure. ### CertStore.CreateRegistryStore `Chilkat 11.7.0 · csharp · CertStore · CreateRegistryStore · method` ```csharp public bool CreateRegistryStore(string regRoot, string regPath); ``` This method, **available only on Microsoft Windows**, creates a new registry-based certificate store. You can save certificates to this store by using the AddCertificate function. Internally, the Microsoft function CertOpenStore is called with the provider type CERT_STORE_PROV_REG and a registry key to create a new, empty certificate store in the Windows registry. `regRoot` can be the string `CurrentUser` or `LocalMachine`. `regPath` is a registry key path such as `Software/MyApplication/Certificates`. Returns true for success, false for failure. ### CertStore.FindCert `Chilkat 11.7.0 · csharp · CertStore · FindCert · method · since 10.1.2` ```csharp public bool FindCert(JsonObject json, Cert cert); ``` Searches for a certificate using criteria from `json` and stores the result in `cert`. If multiple criteria are provided, it searches each one sequentially and returns the first match. Preference is given to non-expired certificates, so if both expired and non-expired certificates match, the non-expired one is selected. See the examples below for details. Returns true for success, false for failure. ### CertStore.GetCert `Chilkat 11.7.0 · csharp · CertStore · GetCert · method · since 10.1.2` ```csharp public bool GetCert(int index, Cert cert); ``` Loads the Nth certificate into `cert`. The first certificate is at index 0. Returns true for success, false for failure. ### CertStore.LoadPemFile `Chilkat 11.7.0 · csharp · CertStore · LoadPemFile · method` ```csharp public bool LoadPemFile(string pemPath); ``` Loads the certificates contained within a PEM formatted file. Returns true for success, false for failure. ### CertStore.LoadPemStr `Chilkat 11.7.0 · csharp · CertStore · LoadPemStr · method` ```csharp public bool LoadPemStr(string pemString); ``` Loads the certificates contained within an in-memory PEM formatted string. Returns true for success, false for failure. ### CertStore.LoadPfxBd `Chilkat 11.7.0 · csharp · CertStore · LoadPfxBd · method · since 10.1.2` ```csharp public bool LoadPfxBd(BinData bd, string password); ``` Loads the PFX/P12 bytes contained in `bd`. `password` is the password to the PFX. Returns true for success, false for failure. ### CertStore.LoadPfxFile `Chilkat 11.7.0 · csharp · CertStore · LoadPfxFile · method` ```csharp public bool LoadPfxFile(string pfxFilename, string password); ``` Loads a PFX file. Once loaded, the certificates within the PFX may be searched via the Find\* methods. It is also possible to iterate from 0 to NumCertficates-1, calling GetCertificate for each index, to retrieve each certificate within the PFX. **Note:** This method does not import certificates into the Windows certificate stores. The purpose of this method is to load a .pfx/.p12 into this object so that other API methods can be called to explore or search the contents of the PFX. The Chilkat Pfx class also provides similar functionality. Returns true for success, false for failure. ### CertStore.OpenCurrentUserStore `Chilkat 11.7.0 · csharp · CertStore · OpenCurrentUserStore · method` ```csharp public bool OpenCurrentUserStore(bool bReadOnly); ``` On Windows, this method opens the **Current-User\\Personal** certificate store in the registry. Set `bReadOnly` to `true` to open the store in read-only mode, which allows you to fetch certificates without adding or removing them. This prevents `permission denied` errors that require read-write access. Starting in version 10.0.0, this method opens the **Apple Keychain** on MacOS and iOS systems. The `bReadOnly` is ignored. After opening the store, you can search for certificates using the Find\* methods. Alternatively, you can iterate through the certificates by indexing from 0 to NumCertificates-1, using GetCertificate to access each one. Returns true for success, false for failure. ### CertStore.OpenFileStore `Chilkat 11.7.0 · csharp · CertStore · OpenFileStore · method` ```csharp public bool OpenFileStore(string filename, bool bReadOnly); ``` (This method only available on Microsoft Windows operating systems.) Opens a file-based certificate store. Once loaded, the certificates within the store may be searched via the Find\* methods. An application may also iterate from 0 to NumCertficates-1 and call GetCertificate to access each certificate by index. Returns true for success, false for failure. ### CertStore.OpenLocalSystemStore `Chilkat 11.7.0 · csharp · CertStore · OpenLocalSystemStore · method` ```csharp public bool OpenLocalSystemStore(bool bReadOnly); ``` (This method is only available on Microsoft Windows operating systems.) Opens the registry-based Local-Computer\\Personal certificate store. Set `bReadOnly` = `true` if only fetching certificates and not updating the certificate store (i.e. certificates will not be added or removed). Setting `bReadOnly` = `true` causes the certificate store to be opened read-only, and will prevent `permission denied` errors caused by the need for read-write permission. Once loaded, the certificates within the store may be searched via the Find\* methods. An application may also iterate from 0 to NumCertficates-1 and call GetCertificate to access each certificate by index. Returns true for success, false for failure. ### CertStore.OpenOutlookStore `Chilkat 11.7.0 · csharp · CertStore · OpenOutlookStore · method` ```csharp public bool OpenOutlookStore(bool bReadOnly); ``` (This method is only available on Microsoft Windows operating systems.) Opens the registry-based Current-User\\Other People certificate store. This is the certificate store use by Microsot Outlook. Set `bReadOnly` = `true` if only fetching certificates and not updating the certificate store (i.e. certificates will not be added or removed). Setting `bReadOnly` = `true` causes the certificate store to be opened read-only, and will prevent `permission denied` errors caused by the need for read-write permission. Once loaded, the certificates within the store may be searched via the Find\* methods. An application may also iterate from 0 to NumCertficates-1 and call GetCertificate to access each certificate by index. Returns true for success, false for failure. ### CertStore.OpenRegistryStore `Chilkat 11.7.0 · csharp · CertStore · OpenRegistryStore · method` ```csharp public bool OpenRegistryStore(string regRoot, string regPath, bool bReadOnly); ``` (This method only available on Microsoft Windows operating systems.) Opens an arbitrary registry-based certificate store. `regRoot` must be `CurrentUser` or `LocalMachine`. `regPath` is a registry path such as `Software/MyApplication/Certificates`. Setting `bReadOnly` = `true` causes the certificate store to be opened read-only, and will prevent `permission denied` errors caused by the need for read-write permission. Once loaded, the certificates within the store may be searched via the Find\* methods. An application may also iterate from 0 to NumCertficates-1 and call GetCertificate to access each certificate by index. Returns true for success, false for failure. ### CertStore.OpenSmartcard `Chilkat 11.7.0 · csharp · CertStore · OpenSmartcard · method · since 10.1.2` ```csharp public bool OpenSmartcard(string csp); ``` This function identifies connected HSM devices such as smart cards and USB tokens, and loads the certificates from each device. It has been significantly enhanced in Chilkat v10.1.2 and is compatible with Windows, MacOS, iOS, and Linux. (Android is not yet supported.) Note: The `csp` is no longer used and is ignored. Applications should pass an empty string. Note: If multiple HSM devices are connected, avoid setting the SmartCardPin property unless all devices share the same PIN. Otherwise, Chilkat will attempt to use that PIN for each device, which could cause issues. Returns true for success, false for failure. ### CertStore.OpenWindowsStore `Chilkat 11.7.0 · csharp · CertStore · OpenWindowsStore · method · since 9.5.0.49` ```csharp public bool OpenWindowsStore(string storeLocation, string storeName, bool bReadOnly); ``` (This method only available on Microsoft Windows operating systems.) Opens a Microsoft Windows certificate store. `storeLocation` must be `CurrentUser` or `LocalMachine`. `storeName` is the name of the certificate store to open. It may be any of the following: - AddressBook: Certificate store for other users. - AuthRoot: Certificate store for third-party certification authorities (CAs). - CertificationAuthority: Certificate store for intermediate certification authorities (CAs). - Disallowed: Certificate store for revoked certificates. - My: Certificate store for personal certificates. - Root: Certificate store for trusted root certification authorities (CAs). - TrustedPeople: Certificate store for directly trusted people and resources. - TrustedPublisher: Certificate store for directly trusted publishers. Setting `bReadOnly` = `true` causes the certificate store to be opened read-only, and will prevent `permission denied` errors caused by the need for read-write permission. Once loaded, the certificates within the store may be searched via the Find\* methods. An application may also iterate from 0 to NumCertficates-1 and call GetCertificate to access each certificate by index. Returns true for success, false for failure. ### CertStore.RemoveCertificate `Chilkat 11.7.0 · csharp · CertStore · RemoveCertificate · method` ```csharp public bool RemoveCertificate(Cert cert); ``` (This method only available on Microsoft Windows operating systems.) Removes the passed certificate from the store. The certificate object passed as the argument can no longer be used once removed. Returns true for success, false for failure. ## Related classes [`BinData`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/csharp/classes/BinData.md), [`Cert`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/csharp/classes/Cert.md), [`JsonObject`](https://www.chilkatsoft.com/ai-docs/v/11.7.0/csharp/classes/JsonObject.md)