Lianja

RSA Sign an Encoded Hash

See more RSA Examples

Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex). Lianja

llSuccess = .F.

// Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
// this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

// Chilkat automatically detects and determines the way in which the HSM is used,
// which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

loCert = createobject("CkCert")

// Set the token/smartcard PIN prior to loading.
loCert.SmartCardPin = "123456"

// Specify the certificate by its common name.
llSuccess = loCert.LoadFromSmartcard("cn=chilkat-rsa-2048")
if (llSuccess = .F.) then
    ? loCert.LastErrorText
    release loCert
    return
endif

? "Signing with the private key for this cert: " + loCert.SubjectCN

// Create data to be hashed and signed.
loBd = createobject("CkBinData")

for i = 0 to 100
    loBd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex")
next

loRsa = createobject("CkRsa")

// Use the certificate's private key for signing.
llSuccess = loRsa.SetX509Cert(loCert,.T.)
if (llSuccess = .F.) then
    ? loRsa.LastErrorText
    release loCert
    release loBd
    release loRsa
    return
endif

// We'll first compute the hash and then pass the encoded hash to be signed.
lcSha256_base64 = loBd.GetHash("sha256","base64")
? "sha256 hash in base64 format: " + lcSha256_base64

// Pass in the base64 hash and return a base64 signature.
loRsa.EncodingMode = "base64"
lcRsaSig_base64 = loRsa.SignHashENC(lcSha256_base64,"sha256")
if (llSuccess = .F.) then
    ? loRsa.LastErrorText
    release loCert
    release loBd
    release loRsa
    return
endif

? "RSA signature as base64: " + lcRsaSig_base64


release loCert
release loBd
release loRsa