(Go) Generate RSA Key and Sign a String

See more RSA Examples

Demonstrates how to generate a new RSA public/private key pair and use it to generate a signature for a string. The (binary) digital signature is returned as a hexidecimalized string.

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    rsa := chilkat.NewRsa()

    // Generate a 2048-bit RSA key.
    success := rsa.GenerateKey(2048)

    // To return the signature in hex.
    rsa.SetEncodingMode("hex")

    strData := "This is the string to be signed."

    // Sign the SHA256 hash of the string.
    hexSig := rsa.SignStringENC(strData,"sha256")

    fmt.Println(*hexSig)
    fmt.Println(rsa.LastErrorText())

    // Now verify the signature:
    success = rsa.VerifyStringENC(strData,"sha256",*hexSig)
    if success == true {
        fmt.Println("Signature verified!")
    }
    else {
        fmt.Println(rsa.LastErrorText())
    }

    // Try it with an invalid signature:
    success = rsa.VerifyStringENC(strData,"sha256","not a valid sig")
    if success == true {
        fmt.Println("Signature verified!")
    }
    else {
        fmt.Println(rsa.LastErrorText())
    }

    // Try it with invalid data:
    success = rsa.VerifyStringENC("Not the original data","sha256",*hexSig)
    if success == true {
        fmt.Println("Signature verified!")
    }
    else {
        fmt.Println(rsa.LastErrorText())
    }

    // Try it with the wrong hash algorithm:
    success = rsa.VerifyStringENC(strData,"sha-1",*hexSig)
    if success == true {
        fmt.Println("Signature verified!")
    }
    else {
        fmt.Println(rsa.LastErrorText())
    }


    rsa.DisposeRsa()