(Go) RSAES-OAEP Encrypt String with AES-128 Content Encryption and SHA256

Encrypts a string using RSAES-OAEP with SHA256 and AES-128 content encryption to produce PKCS7 output (base64 encoded).

Note: This example requires Chilkat v9.5.0.67 or greater.

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

    // First build a string to be encrypted
    sb := chilkat.NewStringBuilder()
    i := 1
    for i < 25 {
        sb.AppendInt(i)
        sb.Append(" the quick brown fox jumped over the lazy dog.\r\n")
        i = i + 1
    }

    fmt.Println(*sb.GetAsString())

    // The string to be encrypted looks like this:

    // 1 the quick brown fox jumped over the lazy dog.
    // 2 the quick brown fox jumped over the lazy dog.
    // 3 the quick brown fox jumped over the lazy dog.
    // 4 the quick brown fox jumped over the lazy dog.
    // 5 the quick brown fox jumped over the lazy dog.
    // 6 the quick brown fox jumped over the lazy dog.
    // ...

    // Load a digital certificate. 
    // We don't need the private key for encryption.
    // Only the public key is needed (which is included in a certificate).
    cert := chilkat.NewCert()
    success := cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem")
    if success != true {
        fmt.Println(cert.LastErrorText())
        sb.DisposeStringBuilder()
        cert.DisposeCert()
        return
    }

    crypt := chilkat.NewCrypt2()

    // Tell the crypt object to use the certificate.
    crypt.SetEncryptCert(cert)

    // Indicate that we want PKI encryption (i.e. public-key infrastructure)
    // to produce a CMS message (Cryptographic Message Syntax/PKCS7),
    // that is be created with RSAES-OAEP padding, SHA256, and AES-128 for the
    // bulk encryption.
    crypt.SetCryptAlgorithm("pki")
    crypt.SetPkcs7CryptAlg("aes")
    crypt.SetKeyLength(128)
    crypt.SetOaepHash("sha256")
    crypt.SetOaepPadding(true)

    // Also, don't forget to be specific about the character encoding (byte representation) of the
    // string to be encrypted.
    crypt.SetCharset("utf-8")

    // Now indicate that the PKCS7 output is to be returned in the base64 encoding.
    crypt.SetEncodingMode("base64")

    base64Pkcs7 := crypt.EncryptStringENC(*sb.GetAsString())
    if crypt.LastMethodSuccess() != true {
        fmt.Println(crypt.LastErrorText())
        sb.DisposeStringBuilder()
        cert.DisposeCert()
        crypt.DisposeCrypt2()
        return
    }

    // Show the output
    fmt.Println(*base64Pkcs7)

    // This base64 can be copy-and-pasted into the form at http://lapo.it/asn1js/
    // to verify that all the chosen algorithms were indeed used.

    fmt.Println("OK.")

    sb.DisposeStringBuilder()
    cert.DisposeCert()
    crypt.DisposeCrypt2()