SMIME Class
Properties Methods Events Configuration Settings Errors
The SMIME component implements the S/MIME standard for encryption and decryption with public key cryptography and X.509 digital certificates.
Syntax
SMIME
Remarks
The SMIME class implements the S/MIME V3 standard for encryption and decryption using Public Key Cryptography Standards (PKCS). In addition the class can be used to both generate and verify RSA digital signatures. Using this class for decrypting or signing requires a valid digital certificate with a private key.
To sign the current data included in Message with a certificate, the Certificate property must be set to a valid Certificate object for the signing certificate. The IncludeCertificate and DetachedSignature properties allow you to specify additional details about the signing process. By setting IncludeCertificate to true, digital certificates can be encoded and included in message signature when signing the document. Including a certificate is the preferred method of building signed messages. In addition the SMIME class can also generate PKCS #7 formatted detached digital signatures and envelopes by specifying DetachedSignature.
To encrypt a message with the class in a PCKS envelope, you must first specify the Certificate for each recipient in the RecipientCerts properties to encrypt the message with. You can easily add these with the AddRecipientCert method. Once you have done this you can call the Encrypt method to encrypt the message with the recipient certificates.
In addition, the class allows you to sign and encrypt simultaneously with the SignAndEncrypt method. You must set all of the properties needed for both Sign and Encrypt
The result of the encrypted or signed data will be replaced in the Message property and the MessageHeaders property will be filled with the appropriate mime headers if applicable.
In addition the SMIME class can be used to verify signatures included in signed messages or documents. The Message property is used to specify the signed message envelope. VerifySignature can then be used to verify the signature. If the message does not have a certificate attached more then likely an exception will be thrown and the class will not be able to verify the signature. If VerifySignature is successful, the SignerCert and SignerCertChain properties will be filled with the certificate information of the message signer. This information can be used to verify the signing certificates.
Decrypting PKCS envelopes is handled with the Decrypt method. When this method is called, the class will attempt to find an appropriate certificate in the Certificate property that matches the encrypting certificate. If it cannot find an appropriate certificate an exception will be thrown and the message will not be decrypted.
Similar to SignAndEncrypt, DecryptAndVerifySignature can be used to both decrypt and verify the message in Message.
Property List
The following is the full list of the properties of the class with short descriptions. Click on the links for further details.
| CertEncoded | The certificate (PEM/base64 encoded). |
| CertStore | The name of the certificate store for the client certificate. |
| CertStorePassword | If the certificate store is of a type that requires a password, this property is used to specify that password in order to open the certificate store. |
| CertStoreType | The type of certificate store for this certificate. |
| CertSubject | The subject of the certificate used for client authentication. |
| DetachedSignature | Specifies whether to include a detached signature when signing a message. |
| EncryptingAlgorithm | Textual description of the encrypting algorithm. |
| IncludeCertificate | Specifies whether to include the signer's certificate with the signed message. |
| IncludeChain | Specifies whether to include the signer's certificate chain with the signed message. |
| InternalHeaders | The headers of the MIME entity inside the encrypted or signed message. |
| Message | The fully encoded or decoded S/MIME message. |
| MessageEncrypted | Whether or not the current message is encrypted. |
| MessageHeaderCount | The number of records in the MessageHeader arrays. |
| MessageHeaderField | This property contains the name of the HTTP header (same case as it is delivered). |
| MessageHeaderValue | This property contains the header contents. |
| MessageHeadersString | String version of headers from the SMIME message. |
| MessageSigned | Whether or not the current message is signed. |
| RecipientCertCount | The number of records in the RecipientCert arrays. |
| RecipientCertEncoded | The certificate (PEM/base64 encoded). |
| SignerCertEncoded | The certificate (PEM/base64 encoded). |
| SignerCertIssuer | The issuer of the certificate. |
| SignerCertSerialNumber | The serial number of the certificate encoded as a string. |
| SignerCertSubject | The subject of the certificate used for client authentication. |
| SignerCertChainCount | The number of records in the SignerCertChain arrays. |
| SignerCertChainEncoded | The certificate (PEM/base64 encoded). |
| SigningAlgorithm | Textual description of the signature hash algorithm. |
Method List
The following is the full list of the methods of the class with short descriptions. Click on the links for further details.
| AddRecipientCert | Used to add recipient certificates used to encrypt messages. |
| Config | Sets or retrieves a configuration setting . |
| Decrypt | Decrypts the current Message . |
| DecryptAndVerifySignature | Decrypts and verifies the signature of the current Message . |
| DecryptFile | Decrypts the contents of a file. |
| Encrypt | Encrypts the current Message . |
| EncryptFile | Encrypts the contents of a file. |
| GetRecipientInfo | Gets the recipient infos for an encrypted message. |
| Reset | Resets the component properties. |
| Sign | Signs the current Message . |
| SignAndEncrypt | Signs and encrypts the current Message . |
| VerifySignature | Verifies the signature of the current Message . |
Event List
The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.
| Error | Information about errors during data delivery. |
| RecipientInfo | Fired for each recipient certificate of the encrypted message. |
| SignerCertInfo | Fired during verification of the signed message. |
Configuration Settings
The following is a list of configuration settings for the class with short descriptions. Click on the links for further details.
| ApplyB64Encoding | Instructs the component to base64 encode the message when signing or encrypting. |
| CSP | The Cryptographic Service Provider. |
| GenerateSignatureTimestamp | Whether to generate timestamps in signatures. |
| IncludeHeaders | Tells the component whether to include the headers when encoding the message. |
| IncludeInternalHeaders | Tells the component whether or not to include the internal headers when encoding the message. |
| ParseInternalHeaders | Tells the component whether or not to parse the message part headers when decrypting a message. |
| RecipientCert | Used to specify the public certificate when using a PEM key to decrypt. |
| RecipientCertFile | Used to specify the public certificate file when using a PEM key to decrypt. |
| UseCryptoAPI | Whether to use the Microsoft Crypto API for cryptographic message generation. |
| CodePage | The system code page used for Unicode to Multibyte translations. |