Visual FoxPro

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.

Visual FoxPro

LOCAL lnSuccess
LOCAL loPubkey
LOCAL loSbPem
LOCAL lnBCrlf
LOCAL lcOriginalData
LOCAL loCrypt
LOCAL lcHashBase64
LOCAL loRsa
LOCAL lnBUsePrivateKey
LOCAL lcEncryptedStr

lnSuccess = 0

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

loPubkey = CreateObject('Chilkat.PublicKey')

loSbPem = CreateObject('Chilkat.StringBuilder')
lnBCrlf = 1
loSbPem.AppendLine("-----BEGIN PUBLIC KEY-----",lnBCrlf)
loSbPem.AppendLine("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF",lnBCrlf)
loSbPem.AppendLine("3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA",lnBCrlf)
loSbPem.AppendLine("04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s",lnBCrlf)
loSbPem.AppendLine("Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF",lnBCrlf)
loSbPem.AppendLine("wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE",lnBCrlf)
loSbPem.AppendLine("f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W",lnBCrlf)
loSbPem.AppendLine("SwIDAQAB",lnBCrlf)
loSbPem.AppendLine("-----END PUBLIC KEY-----",lnBCrlf)

* Load the public key object from the PEM. 
lnSuccess = loPubkey.LoadFromString(loSbPem.GetAsString())
IF (lnSuccess = 0) THEN
    ? loPubkey.LastErrorText
    RELEASE loPubkey
    RELEASE loSbPem
    CANCEL
ENDIF

lcOriginalData = "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:
loCrypt = CreateObject('Chilkat.Crypt2')
loCrypt.HashAlgorithm = "SHA-256"
loCrypt.EncodingMode = "base64"
lcHashBase64 = loCrypt.HashStringENC(lcOriginalData)

* Setup RSA to use OAEP padding with SHA-1 for the mask function.
loRsa = CreateObject('Chilkat.Rsa')
loRsa.PkcsPadding = 0
loRsa.OaepHash = "SHA256"
loRsa.UsePublicKey(loPubkey)
loRsa.EncodingMode = "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).
loRsa.Charset = "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.
lnBUsePrivateKey = 0
lcEncryptedStr = loRsa.EncryptStringENC(lcHashBase64,lnBUsePrivateKey)
IF (loRsa.LastMethodSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loPubkey
    RELEASE loSbPem
    RELEASE loCrypt
    RELEASE loRsa
    CANCEL
ENDIF

? "Base64 RSA encrypted output: " + lcEncryptedStr

RELEASE loPubkey
RELEASE loSbPem
RELEASE loCrypt
RELEASE loRsa