PublicKey Class
Represents a certificate's public key information. This class cannot be inherited.
Assembly: System (in System.dll)
The PublicKey type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | EncodedKeyValue | Gets the ASN.1-encoded representation of the public key value. |
![]() | EncodedParameters | Gets the ASN.1-encoded representation of the public key parameters. |
![]() | Key | Gets an RSACryptoServiceProvider or DSACryptoServiceProvider object representing the public key. |
![]() | Oid | Gets an object identifier (OID) object of the public key. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
The PublicKey object contains the object identifier (Oid) representing the public key algorithm, the ASN-encoded parameters, and the ASN.1-encoded key value.
The following example demonstrates how to use the public key from a X509Certificate2 object to encrypt a file. It also shows how to decrypt the encrypted file using the private key for that certificate.
The following example creates a command-line executable that takes a certificate file as an argument and prints various certificate properties to the console.
#using <System.dll> using namespace System; using namespace System::Security::Cryptography; using namespace System::Security::Permissions; using namespace System::IO; using namespace System::Security::Cryptography::X509Certificates; //Reads a file. array<Byte>^ ReadFile( String^ fileName ) { FileStream^ f = gcnew FileStream( fileName,FileMode::Open,FileAccess::Read ); int size = (int)f->Length; array<Byte>^data = gcnew array<Byte>(size); size = f->Read( data, 0, size ); f->Close(); return data; } [SecurityPermissionAttribute(SecurityAction::LinkDemand, Unrestricted = true)] int main() { array<String^>^args = Environment::GetCommandLineArgs(); //Test for correct number of arguments. if ( args->Length < 2 ) { Console::WriteLine( "Usage: CertInfo <filename>" ); return -1; } try { System::Security::Cryptography::X509Certificates::X509Certificate2 ^ x509 = gcnew System::Security::Cryptography::X509Certificates::X509Certificate2; //Create X509Certificate2 object from .cer file. array<Byte>^rawData = ReadFile( args[ 1 ] ); x509->Import(rawData); //Print to console information contained in the certificate. Console::WriteLine( "{0}Subject: {1}{0}", Environment::NewLine, x509->Subject ); Console::WriteLine( "{0}Issuer: {1}{0}", Environment::NewLine, x509->Issuer ); Console::WriteLine( "{0}Version: {1}{0}", Environment::NewLine, x509->Version ); Console::WriteLine( "{0}Valid Date: {1}{0}", Environment::NewLine, x509->NotBefore ); Console::WriteLine( "{0}Expiry Date: {1}{0}", Environment::NewLine, x509->NotAfter ); Console::WriteLine( "{0}Thumbprint: {1}{0}", Environment::NewLine, x509->Thumbprint ); Console::WriteLine( "{0}Serial Number: {1}{0}", Environment::NewLine, x509->SerialNumber ); Console::WriteLine( "{0}Friendly Name: {1}{0}", Environment::NewLine, x509->PublicKey->Oid->FriendlyName ); Console::WriteLine( "{0}Public Key Format: {1}{0}", Environment::NewLine, x509->PublicKey->EncodedKeyValue->Format(true) ); Console::WriteLine( "{0}Raw Data Length: {1}{0}", Environment::NewLine, x509->RawData->Length ); Console::WriteLine( "{0}Certificate to string: {1}{0}", Environment::NewLine, x509->ToString( true ) ); Console::WriteLine( "{0}Certificate to XML String: {1}{0}", Environment::NewLine, x509->PublicKey->Key->ToXmlString( false ) ); //Add the certificate to a X509Store. X509Store ^ store = gcnew X509Store; store->Open( OpenFlags::MaxAllowed ); store->Add( x509 ); store->Close(); } catch ( DirectoryNotFoundException^ ) { Console::WriteLine( "Error: The directory specified could not be found." ); } catch ( IOException^ ) { Console::WriteLine( "Error: A file in the directory could not be accessed." ); } catch ( NullReferenceException^ ) { Console::WriteLine( "File must be a .cer file. Program does not have access to that type of file." ); } }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
