(PowerBuilder) ECDSA Sign Data and Verify Signature

Demonstrates using the Elliptic Curve Digital Signature Algorithm to hash data and sign it. Also demonstrates how to verify the ECDSA signature.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Crypt
string ls_Hash1
string ls_Hash2
oleobject loo_PrivKey
integer li_Success
oleobject loo_Prng
oleobject loo_Ecdsa
string ls_EcdsaSigBase64
oleobject loo_PubKey
integer li_Result

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

// To create an ECDSA signature, the data first needs to be hashed.  Then the hash
// is signed.

// Use Chilkat Crypt2 to generate a hash for any of the following
// hash algorithms: SHA256, SHA384, SHA512, SHA1, MD5, MD2, HAVAL, RIPEMD128/160/256/320

loo_Crypt = create oleobject
li_rc = loo_Crypt.ConnectToNewObject("Chilkat_9_5_0.Crypt2")
if li_rc < 0 then
    destroy loo_Crypt
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_Crypt.HashAlgorithm = "SHA256"
loo_Crypt.Charset = "utf-8"
loo_Crypt.EncodingMode = "base64"

// Hash a string.
ls_Hash1 = loo_Crypt.HashStringENC("The quick brown fox jumps over the lazy dog")
Write-Debug "hash1 = " + ls_Hash1

// Or hash a file..
ls_Hash2 = loo_Crypt.HashFileENC("qa_data/hamlet.xml")
Write-Debug "hash2 = " + ls_Hash2

// (The Crypt2 API provides many other ways to hash data..)

// -----------------------------------------------------------
// An ECDSA private key is used for signing.  The public key is for signature verification.
// Load our ECC private key.
// Our private key file contains this:

// 	// -----BEGIN PRIVATE KEY-----
// 	MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg3J8q/24D1sEKGdP9
// 	72MGYElLGpw/a56Y3t6pfON3uhShRANCAATlSmoizyhAwoYZAOuFBATl07/1RR54
// 	a1Dzfm16grxJe666AGKR+bSs24hk7TEpaeCTvT8YOOM3l+xKFg7zq6Q9
// 	-----END PRIVATE KEY-----

loo_PrivKey = create oleobject
li_rc = loo_PrivKey.ConnectToNewObject("Chilkat_9_5_0.PrivateKey")

li_Success = loo_PrivKey.LoadPemFile("qa_data/ecc/secp256r1-key-pkcs8.pem")
if li_Success <> 1 then
    Write-Debug loo_PrivKey.LastErrorText
    destroy loo_Crypt
    destroy loo_PrivKey
    return
end if

// We'll need a PRNG source for random number generation.
// Use Chilkat's PRNG (for the Fortuna PRNG algorithm).
loo_Prng = create oleobject
li_rc = loo_Prng.ConnectToNewObject("Chilkat_9_5_0.Prng")

// Sign the hash..
loo_Ecdsa = create oleobject
li_rc = loo_Ecdsa.ConnectToNewObject("Chilkat_9_5_0.Ecc")

ls_EcdsaSigBase64 = loo_Ecdsa.SignHashENC(ls_Hash1,"base64",loo_PrivKey,loo_Prng)
if loo_Ecdsa.LastMethodSuccess <> 1 then
    Write-Debug loo_Ecdsa.LastErrorText
    destroy loo_Crypt
    destroy loo_PrivKey
    destroy loo_Prng
    destroy loo_Ecdsa
    return
end if

Write-Debug "ECDSA signature = " + ls_EcdsaSigBase64

// -----------------------------------------------------------
// Now let's verify the signature using the public key.

loo_PubKey = create oleobject
li_rc = loo_PubKey.ConnectToNewObject("Chilkat_9_5_0.PublicKey")

li_Success = loo_PubKey.LoadFromFile("qa_data/ecc/secp256r1-pubkey.pem")
if li_Success <> 1 then
    Write-Debug loo_PubKey.LastErrorText
    destroy loo_Crypt
    destroy loo_PrivKey
    destroy loo_Prng
    destroy loo_Ecdsa
    destroy loo_PubKey
    return
end if

li_Result = loo_Ecdsa.VerifyHashENC(ls_Hash1,ls_EcdsaSigBase64,"base64",loo_PubKey)
if li_Result = 1 then
    Write-Debug "Signature is valid."
    destroy loo_Crypt
    destroy loo_PrivKey
    destroy loo_Prng
    destroy loo_Ecdsa
    destroy loo_PubKey
    return
end if

if li_Result = 0 then
    Write-Debug "Signature is invalid."
    destroy loo_Crypt
    destroy loo_PrivKey
    destroy loo_Prng
    destroy loo_Ecdsa
    destroy loo_PubKey
    return
end if

if li_Result < 0 then
    Write-Debug loo_Ecdsa.LastErrorText
    Write-Debug "The VerifyHashENC method call failed."
    destroy loo_Crypt
    destroy loo_PrivKey
    destroy loo_Prng
    destroy loo_Ecdsa
    destroy loo_PubKey
    return
end if



destroy loo_Crypt
destroy loo_PrivKey
destroy loo_Prng
destroy loo_Ecdsa
destroy loo_PubKey