Menu
The current OpenPGP standard uses key pairs with RSA, DH/DSS, and ECC asymmetric encryption keys. In this chapter, we are going to generate an RSA key pair with DidiSoft OpenPGP Library for .NET.
Each OpenPGP key pair contains additional information which we have to specify upfront:
- User ID of the key owner, usually in the form “Person name or Organization name <owners_email@website>“
- Size in bits of the encryption key (must be over 1024 and up to 4096)
- list of preferred symmetric encryption algorithms
- list of preferred hash algorithms
- list of preferred compression algorithms
- key expiration date (if the key will be with a time-limited use)
Generate - rsaparameters private key c#. Best way to initaite RSACryptoServiceProvider from x509Certificate2? (2) The recommended way is to use RSA base class and call. If on the other hand the private key is present the RSA Parameters will contain D, DP, DQ, Exponent, InverseQ, Modulus, P and Q. In the first section of this tool, you can generate public or private keys. To do so, select the RSA key size among 515, 1024, 2048 and 4096 bit click on the button. This will generate the keys for you. For encryption and decryption, enter the plain text and supply the key. Encryption and Decryption in RSA. Example of RSA: Here is an example of RSA encryption and decryption with generation of the public and private key. Generate public and private key: Encryption and Decryption. How to use the RSA Algorithm in a C# Windows Forms application. Open Visual Studio. Online RSA Key Generator. Key Size 1024 bit. 512 bit; 1024 bit; 2048 bit; 4096 bit Generate New Keys Async. RSA Encryption Test. Text to encrypt: Encrypt / Decrypt.
The original PGP(r) software uses a naming convention for delimiting the email in the User ID label with < and > like: “Richard C. <[email protected]>”
C# Generate Rsa Private Key
Generate RSA based OpenPGP key pair
Below is a short example program that shows how to generate an RSA OpenPGP key pair in a KeyStore object.
C# example
VB.NET example
The above code generates a key pair that does not expire. An overloaded method exists that accepts an expiration date as the last parameter. A key pair can also be generated without using a KeyStore, through a similar method in the PGPKeyPair class.
After the key pair is generated it can be exported. Usually, we will send the public key part of it to our partners.
Below is a screenshot of the key properties after the key is imported in PGP (r) Desktop version 10. Please note that in our example above we have omitted the < > around the email part of the User ID and that’s why PGP(r) displays the name and email part of the User ID together.
Async support
In order to create a key pair asynchronously, we have to use the DidiSoft.Pgp.KeyStoreAsync class which provides the same key creation methods with Async suffixes.
Summary
In this chapter, we have discussed RSA OpenPGP key generation with DidiSoft OpenPGP Library for .NET.
You may also consider reading DH/DSS OpenPGP key pair generation, ECC key pair generation, keys exporting and importing.
Example application
In the library installation folder under the Examples subfolder, you can find the project KeyToolCS (KeyToolVB for VB.NET), a demo WinForms application that illustrates OpenPGP key generation as well as many other operations that can be performed over OpenPGP keys.
List of methods used:
KeyStore.GenerateKeyPair
KeyStore.GenerateRsaKeyPair
-->KeyStore.GenerateRsaKeyPair
Cryptographic digital signatures use public key algorithms to provide data integrity. When you sign data with a digital signature, someone else can verify the signature, and can prove that the data originated from you and was not altered after you signed it. For more information about digital signatures, see Cryptographic Services.
This topic explains how to generate and verify digital signatures using classes in the System.Security.Cryptography namespace.
Generating Signatures
Digital signatures are usually applied to hash values that represent larger data. The following example applies a digital signature to a hash value. First, a new instance of the RSACryptoServiceProvider class is created to generate a public/private key pair. Next, the RSACryptoServiceProvider is passed to a new instance of the RSAPKCS1SignatureFormatter class. This transfers the private key to the RSAPKCS1SignatureFormatter, which actually performs the digital signing. Before you can sign the hash code, you must specify a hash algorithm to use. This example uses the SHA1 algorithm. Finally, the CreateSignature method is called to perform the signing.
![C# create rsa private key C# create rsa private key](/uploads/1/2/6/1/126140091/585735389.png)
Due to collision problems with SHA1, Microsoft recommends SHA256 or better.
Signing XML Files
The .NET Framework provides the System.Security.Cryptography.Xml namespace, which enables you sign XML. Signing XML is important when you want to verify that the XML originates from a certain source. For example, if you are using a stock quote service that uses XML, you can verify the source of the XML if it is signed.
The classes in this namespace follow the XML-Signature Syntax and Processing recommendation from the World Wide Web Consortium.
Verifying Signatures
To verify that data was signed by a particular party, you must have the following information:
- The public key of the party that signed the data.
- The digital signature.
- The data that was signed.
- The hash algorithm used by the signer.
To verify a signature signed by the RSAPKCS1SignatureFormatter class, use the RSAPKCS1SignatureDeformatter class. The RSAPKCS1SignatureDeformatter class must be supplied the public key of the signer. You will need the values of the modulus and the exponent to specify the public key. (The party that generated the public/private key pair should provide these values.) First create an RSACryptoServiceProvider object to hold the public key that will verify the signature, and then initialize an RSAParameters structure to the modulus and exponent values that specify the public key.
The following code shows the creation of an RSAParameters structure. The
Modulus
property is set to the value of a byte array called modulusData
and the Exponent
property is set to the value of a byte array called exponentData
.After you have created the RSAParameters object, you can initialize a new instance of the RSACryptoServiceProvider class to the values specified in RSAParameters. The RSACryptoServiceProvider is, in turn, passed to the constructor of an RSAPKCS1SignatureDeformatter to transfer the key.
The following example illustrates this process. In this example,
hashValue
and signedHashValue
are arrays of bytes provided by a remote party. The remote party has signed the hashValue
using the SHA1 algorithm, producing the digital signature signedHashValue
. The RSAPKCS1SignatureDeformatter.VerifySignature method verifies that the digital signature is valid and was used to sign the hashValue
.Generate Public Private Key Pair
This code fragment will display '
The signature is valid
' if the signature is valid and 'The signature is not valid
' if it is not.