Tcl

Ed25519ph Sign and Verify

See more Ed25519 Examples

Demonstrates how to create an Ed25519ph signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.91 or greater.

Tcl

load ./chilkat.dll

set success 0

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

# Use the following test vector from https://www.rfc-editor.org/rfc/rfc8032#page-30

#    -----TEST abc
# 
#    ALGORITHM:
#    Ed25519ph
# 
#    SECRET KEY:
#    833fe62409237b9d62ec77587520911e
#    9a759cec1d19755b7da901b96dca3d42
# 
#    PUBLIC KEY:
#    ec172b93ad5e563bf4932c70e1245034
#    c35467ef2efd4d64ebf819683467e2bf
# 
#    MESSAGE (length 3 bytes):
#    616263
# 
#    SIGNATURE:
#    98a70222f0b8121aa9d30f813d683f80
#    9e462b469c7ff87639499bb94e6dae41
#    31f85042463c2a355a2003d062adf5aa
#    a10b8c61e636062aaad11c2a26083406

set privKeyHex "833fe62409237b9d62ec77587520911e9a759cec1d19755b7da901b96dca3d42"
set pubKeyHex "ec172b93ad5e563bf4932c70e1245034c35467ef2efd4d64ebf819683467e2bf"

set privKey [new_CkPrivateKey]

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_AppendEncoded $bd "616263" "hex"

set eddsa [new_CkEdDSA]

# Indicate we want the Ed25519ph instance.
CkEdDSA_put_Algorithm $eddsa "Ed25519ph"

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

puts "signature = $hexSig"

# The expected output is: 98a70222f0b8121aa9d30f813d683f80....

# 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 Ed25519ph signature is verified!"

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