RSA Class

Properties Methods Events Configuration Settings Errors

Implements RSA public-key cryptography to encrypt/decrypt and sign/verify messages.

Syntax

ipworksencrypt.rsa()

Remarks

The RSA class implements RSA public-key cryptography to encrypt/decrypt messages and sign/verify hash signatures.

To begin you must either specify an existing key or create a new key. Existing private keys may be specified by setting the Key* properties. To create a new key call CreateKey. Alternatively an existing certificate may be specified by setting the Certificate* properties

Signing

To sign data first set Key or Certificate. Specify the input data using InputFile or InputMessage. Next call Sign. The class will populate HashValue and HashSignature. After calling Sign the public key must be sent to the recipient along with HashSignature.

Encrypting

To encrypt data set RecipientKey or RecipientCert. Specify the input data using InputFile or InputMessage. Next call Encrypt. The class will populate OutputMessage, or write to the file specified by OutputFile.

Signature Verification

To verify a signature specify the input data using InputFile or InputMessage. Set SignerKey or SignerCert. Next set HashSignature and call VerifySignature. The VerifySignature method will return True if the signature was successfully verified.

Decrypting

To decrypt data first set Key or Certificate. Specify the input data using InputFile or InputMessage. Next call Decrypt. The class will populate OutputMessage, or write to the file specified by OutputFile.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

OutputFile
OutputMessage: The output data is written to this property if no other destination is specified.

RSA Keys

A RSA key is made up of a number of individual parameters.

The public key consists of the following parameters:

KeyModulus
KeyExponent

The class also includes the KeyPublicKey property which holds the PEM formatted public key for ease of use. This is helpful if you are in control of both sides of the encryption/signing and decryption/signature verification process. When sending the public key to a recipient note that not all implementations will support using the PEM formatted value in KeyPublicKey in which case the individual parameters must be sent.

The private key may be represented in one of two ways. Both are mathematically equivalent. Private key format 1:

KeyModulus
KeyP
KeyQ
KeyDP
KeyDQ

Private key format 2 is simpler but has decreased performance when decrypting and signing. This format is:

KeyModulus
KeyD

The class also include the KeyPrivateKey property which holds the PEM formatted private key for ease of use. This is helpful for storing the private key more easily.

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.


Certificate	The certificate used for signing and decryption.
HashAlgorithm	The hash algorithm used for signing and signature verification.
HashSignature	The hash signature.
HashValue	The hash value of the data.
InputFile	The file to process.
InputMessage	The message to process.
Key	The RSA key.
OutputFile	The output file when encrypting or decrypting.
OutputMessage	The output message after processing.
Overwrite	Indicates whether or not the class should overwrite files.
RecipientCert	The certificate used for encryption.
RecipientKey	The recipient's public key used when encrypting.
SignerCert	The certificate used for signature verification.
SignerKey	The public key used to verify the signature.
UseHex	Whether input or output is hex encoded.
UseOAEP	Whether to use Optimal Asymmetric Encryption Padding (OAEP).
UsePSS	Whether to use RSA-PSS during signing and verification.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.


Config	Sets or retrieves a configuration setting.
CreateKey	Creates a new key.
Decrypt	Decrypts the input data using the specified private key.
Encrypt	Encrypts the input data using the recipient's public key.
Reset	Resets the class.
Sign	Creates a hash signature.
VerifySignature	Verifies the signature for the specified data.

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.
Progress	Fired as progress is made.

Configuration Settings

The following is a list of configuration settings for the class with short descriptions. Click on the links for further details.


KeyFormat	How the public and private key are formatted.
KeySize	The size, in bits, of the secret key.
OAEPMGF1HashAlgorithm	The MGF1 hash algorithm used with OAEP.
OAEPParams	The hex encoded OAEP parameters.
OAEPRSAHashAlgorithm	The RSA hash algorithm used with OAEP.
BuildInfo	Information about the product's build.
CodePage	The system code page used for Unicode to Multibyte translations.
LicenseInfo	Information about the current license.
UseInternalSecurityAPI	Tells the class whether or not to use the system security libraries or an internal implementation.