(Tcl) Ed25519 Sign and Verify

Demonstrates how to create an Ed25519 signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.83 or greater.

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load ./chilkat.dll

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

set privKeyHex "1498b5467a63dffa2dc9d9e069caf075d16fc33fdd4c3b01bfadae6433767d93"
set pubKeyHex "b7a3c12dc0c8c748ab07525b701122b88bd78f600c76342d27f25e5f92444cde"

set privKey [new_CkPrivateKey]

# This example shows only one way of loading an Ed25519 private key.
# Chilkat can load other formats (JWK, PEM, ASN.1 DER, etc.)  
# You may do so by calling LoadAnyFormat or LoadAnyFormatFile.
set success [CkPrivateKey_LoadEd25519 $privKey $privKeyHex $pubKeyHex]
if {$success == 0} then {
    puts [CkPrivateKey_lastErrorText $privKey]
    delete_CkPrivateKey $privKey
    exit
}

# The data to be signed...
set bd [new_CkBinData]

CkBinData_AppendString $bd "Message for Ed25519 signing" "utf-8"

set eddsa [new_CkEdDSA]

set hexSig [CkEdDSA_signBdENC $eddsa $bd "hexlower" $privKey]

puts "signature = $hexSig"

# The expected output is: 6dd355667fae4eb43c6e0ab92e870edb2de0a88cae12dbd8591507f584fe4912babff497f1b8edf9567d2483d54ddc6459bea7855281b7a246a609e3001a4e08

# Verify the signature..
set pubKey [new_CkPublicKey]

set success [CkPublicKey_LoadEd25519 $pubKey $pubKeyHex]
if {$success == 0} then {
    puts [CkPublicKey_lastErrorText $pubKey]
    delete_CkPrivateKey $privKey
    delete_CkBinData $bd
    delete_CkEdDSA $eddsa
    delete_CkPublicKey $pubKey
    exit
}

set bVerified [CkEdDSA_VerifyBdENC $eddsa $bd $hexSig "hexlower" $pubKey]
if {$bVerified == 0} then {
    puts [CkEdDSA_lastErrorText $eddsa]
    puts "Failed to verify the signature."
    delete_CkPrivateKey $privKey
    delete_CkBinData $bd
    delete_CkEdDSA $eddsa
    delete_CkPublicKey $pubKey
    exit
}

puts "The Ed25519 signature is verified!"

delete_CkPrivateKey $privKey
delete_CkBinData $bd
delete_CkEdDSA $eddsa
delete_CkPublicKey $pubKey