PublicKey Class
Represents a certificate's public key information. This class cannot be inherited.
Assembly: System (in System.dll)
| Name | Description | |
|---|---|---|
![]() | PublicKey(Oid^, AsnEncodedData^, AsnEncodedData^) | Initializes a new instance of the PublicKey class using an object identifier (OID) object of the public key, an ASN.1-encoded representation of the public key parameters, and an ASN.1-encoded representation of the public key value. |
| 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.) |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetType() | |
![]() | 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." ); } }
Available since 2.0
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

