Go

RSA Encrypt Hash using SHA256 hash function and SHA1 mask function

See more RSA Examples

How can this Javascript be duplicated using Chilkat?

function a(e, t) {
                var r = s.pki.publicKeyFromPem(e)
                  , n = r.encrypt(t, "RSA-OAEP", {
                    md: s.md.sha256.create(),
                    mgf1: {
                        md: s.md.sha1.create()
                    }
                });
                return s.util.encode64(n)
            }

Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens, even using the same data and key, the result will be different -- but still valid. One should not expect to get the same output.

Go

    success := false

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

    pubkey := chilkat.NewPublicKey()

    sbPem := chilkat.NewStringBuilder()
    bCrlf := true
    sbPem.AppendLine("-----BEGIN PUBLIC KEY-----",bCrlf)
    sbPem.AppendLine("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF",bCrlf)
    sbPem.AppendLine("3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA",bCrlf)
    sbPem.AppendLine("04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s",bCrlf)
    sbPem.AppendLine("Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF",bCrlf)
    sbPem.AppendLine("wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE",bCrlf)
    sbPem.AppendLine("f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W",bCrlf)
    sbPem.AppendLine("SwIDAQAB",bCrlf)
    sbPem.AppendLine("-----END PUBLIC KEY-----",bCrlf)

    // Load the public key object from the PEM. 
    success = pubkey.LoadFromString(*sbPem.GetAsString())
    if success == false {
        fmt.Println(pubkey.LastErrorText())
        pubkey.DisposePublicKey()
        sbPem.DisposeStringBuilder()
        return
    }

    originalData := "This is the original data to be SHA-256 hashed and RSA encrypted."

    // First we SHA-256 hash the original data to get the hash in base64 format:
    crypt := chilkat.NewCrypt2()
    crypt.SetHashAlgorithm("SHA-256")
    crypt.SetEncodingMode("base64")
    hashBase64 := crypt.HashStringENC(originalData)

    // Setup RSA to use OAEP padding with SHA-1 for the mask function.
    rsa := chilkat.NewRsa()
    rsa.SetPkcsPadding(false)
    rsa.SetOaepHash("SHA256")
    rsa.UsePublicKey(pubkey)
    rsa.SetEncodingMode("base64")

    // We can provide a binary encoding mode, such as "base64", "hex", "base64url", etc.
    // for the Charset property.   The Charset property was previously limited to character encodings, such as
    // "utf-8", "iso-8859-1", etc.  If a binary encoding is used, then the string passed in is decoded to the binary
    // bytes as indicated.  (If an actual charset, such as "utf-8" is used, then the input string is converted to the
    // byte representation of the charset, and then encrypted.)

    // Given that a hash is composed of non-text binary bytes, we'll set the Charset property equal to "base64" 
    // (because we have the base64 hash from above).
    rsa.SetCharset("base64")

    // Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens,
    // even using the same data and key, the result will be different --  but still valid.  One should not expect
    // to get the same output.
    bUsePrivateKey := false
    encryptedStr := rsa.EncryptStringENC(*hashBase64,bUsePrivateKey)
    if rsa.LastMethodSuccess() == false {
        fmt.Println(rsa.LastErrorText())
        pubkey.DisposePublicKey()
        sbPem.DisposeStringBuilder()
        crypt.DisposeCrypt2()
        rsa.DisposeRsa()
        return
    }

    fmt.Println("Base64 RSA encrypted output: ", *encryptedStr)

    pubkey.DisposePublicKey()
    sbPem.DisposeStringBuilder()
    crypt.DisposeCrypt2()
    rsa.DisposeRsa()