(Xojo Plugin) 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
Dim sb As New Chilkat.StringBuilder
Dim i As Int32
i = 1
While i < 25
    Dim success As Boolean
    success = sb.AppendInt(i)
    success = sb.Append(" the quick brown fox jumped over the lazy dog." + EndOfLine.Windows)
    i = i + 1
Wend

System.DebugLog(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).
Dim cert As New Chilkat.Cert
Dim success As Boolean
success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem")
If (success <> True) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

Dim crypt As New Chilkat.Crypt2

// Tell the crypt object to use the certificate.
success = 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.CryptAlgorithm = "pki"
crypt.Pkcs7CryptAlg = "aes"
crypt.KeyLength = 128
crypt.OaepHash = "sha256"
crypt.OaepPadding = True

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

// Now indicate that the PKCS7 output is to be returned in the base64 encoding.
crypt.EncodingMode = "base64"

Dim base64Pkcs7 As String
base64Pkcs7 = crypt.EncryptStringENC(sb.GetAsString())
If (crypt.LastMethodSuccess <> True) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

// Show the output
System.DebugLog(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.

System.DebugLog("OK.")