(Go) RSA Encrypt RSA/ECB/OAEPWithSHA1AndMGF1Padding

Demonstrates how to RSA encrypt using RSA/ECB/OAEPWithSHA1AndMGF1Padding. Also demonstrates RSA/ECB/OAEPWithSHA-256AndMGF1Padding. Both of these terms are from Java's JCE. Note: In this context, "ECB" doesn't actually mean anything. It's a symmetric cipher mode that doesn't apply (or make sense) in this context.

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

    rsa := chilkat.NewRsa()

    // First load a public key object with a public key.
    // In this case, we'll load it from a file.
    pubkey := chilkat.NewPublicKey()
    success := pubkey.LoadFromFile("qa_data/pem/rsa_public.pem")
    if success != true {
        fmt.Println(pubkey.LastErrorText())
        rsa.DisposeRsa()
        pubkey.DisposePublicKey()
        return
    }

    // RSA encryption is limited to small amounts of data. The limit
    // is typically a few hundred bytes and is based on the key size and
    // padding (OAEP vs. PKCS1_5).  RSA encryption is typically used for
    // encrypting hashes or symmetric (bulk encryption algorithm) secret keys.
    plainText := "Time is an illusion. Lunchtime doubly so."

    // Import the public key to be used for encrypting.
    success = rsa.ImportPublicKeyObj(pubkey)

    // To get OAEP padding, set the OaepPadding property:
    rsa.SetOaepPadding(true)

    // To use SHA1 or SHA-256, set the OaepHash property
    rsa.SetOaepHash("sha256")
    // for SHA1 --
    rsa.SetOaepHash("sha1")

    // Indicate we'll want hex output
    rsa.SetEncodingMode("hex")

    // Encrypt..
    usePrivateKey := false
    encryptedStr := rsa.EncryptStringENC(plainText,usePrivateKey)
    fmt.Println(*encryptedStr)

    // -------------------------------------------------
    // Now decrypt with the matching private key.
    rsa2 := chilkat.NewRsa()

    privKey := chilkat.NewPrivateKey()
    success = privKey.LoadEncryptedPem("qa_data/pem/rsa_passwd.pem","passwd")
    if success != true {
        fmt.Println(privKey.LastErrorText())
        rsa.DisposeRsa()
        pubkey.DisposePublicKey()
        rsa2.DisposeRsa()
        privKey.DisposePrivateKey()
        return
    }

    success = rsa2.ImportPrivateKeyObj(privKey)

    // Make sure we have the same settings used for encryption.
    rsa2.SetOaepPadding(true)
    rsa2.SetEncodingMode("hex")
    rsa2.SetOaepHash("sha1")

    originalStr := rsa2.DecryptStringENC(*encryptedStr,true)

    fmt.Println(*originalStr)

    rsa.DisposeRsa()
    pubkey.DisposePublicKey()
    rsa2.DisposeRsa()
    privKey.DisposePrivateKey()