Go

RSA Sign an Encoded Hash

See more RSA Examples

Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex). Go

    success := false

    // Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
    // this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

    // Chilkat automatically detects and determines the way in which the HSM is used,
    // which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

    cert := chilkat.NewCert()

    // Set the token/smartcard PIN prior to loading.
    cert.SetSmartCardPin("123456")

    // Specify the certificate by its common name.
    success = cert.LoadFromSmartcard("cn=chilkat-rsa-2048")
    if success == false {
        fmt.Println(cert.LastErrorText())
        cert.DisposeCert()
        return
    }

    fmt.Println("Signing with the private key for this cert: ", cert.SubjectCN())

    // Create data to be hashed and signed.
    bd := chilkat.NewBinData()
    var i int
    for i = 0; i <= 100; i++ {
        bd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex")
    }

    rsa := chilkat.NewRsa()

    // Use the certificate's private key for signing.
    success = rsa.SetX509Cert(cert,true)
    if success == false {
        fmt.Println(rsa.LastErrorText())
        cert.DisposeCert()
        bd.DisposeBinData()
        rsa.DisposeRsa()
        return
    }

    // We'll first compute the hash and then pass the encoded hash to be signed.
    sha256_base64 := bd.GetHash("sha256","base64")
    fmt.Println("sha256 hash in base64 format: ", *sha256_base64)

    // Pass in the base64 hash and return a base64 signature.
    rsa.SetEncodingMode("base64")
    rsaSig_base64 := rsa.SignHashENC(*sha256_base64,"sha256")
    if success == false {
        fmt.Println(rsa.LastErrorText())
        cert.DisposeCert()
        bd.DisposeBinData()
        rsa.DisposeRsa()
        return
    }

    fmt.Println("RSA signature as base64: ", *rsaSig_base64)

    cert.DisposeCert()
    bd.DisposeBinData()
    rsa.DisposeRsa()