Lianja

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.

Lianja

llSuccess = .F.

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

loPubkey = createobject("CkPublicKey")

loSbPem = createobject("CkStringBuilder")
llBCrlf = .T.
loSbPem.AppendLine("-----BEGIN PUBLIC KEY-----",llBCrlf)
loSbPem.AppendLine("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF",llBCrlf)
loSbPem.AppendLine("3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA",llBCrlf)
loSbPem.AppendLine("04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s",llBCrlf)
loSbPem.AppendLine("Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF",llBCrlf)
loSbPem.AppendLine("wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE",llBCrlf)
loSbPem.AppendLine("f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W",llBCrlf)
loSbPem.AppendLine("SwIDAQAB",llBCrlf)
loSbPem.AppendLine("-----END PUBLIC KEY-----",llBCrlf)

// Load the public key object from the PEM. 
llSuccess = loPubkey.LoadFromString(loSbPem.GetAsString())
if (llSuccess = .F.) then
    ? loPubkey.LastErrorText
    release loPubkey
    release loSbPem
    return
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("CkCrypt2")
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("CkRsa")
loRsa.PkcsPadding = .F.
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.
llBUsePrivateKey = .F.
lcEncryptedStr = loRsa.EncryptStringENC(lcHashBase64,llBUsePrivateKey)
if (loRsa.LastMethodSuccess = .F.) then
    ? loRsa.LastErrorText
    release loPubkey
    release loSbPem
    release loCrypt
    release loRsa
    return
endif

? "Base64 RSA encrypted output: " + lcEncryptedStr


release loPubkey
release loSbPem
release loCrypt
release loRsa