Lua Requires Chilkat v11.0.0+

Verify an RSA Signature Against the Signed Hash

See more Apple Keychain Examples

Demonstrates how to validate an RSA Signature against the hash that was signed. Lua

local chilkat = require("chilkat")

local bd = chilkat.BinData.new()
for i = 0, 100 do
    bd:append_encoded("000102030405060708090A0B0C0D0E0F", "hex")
end

local sha256_base64 = bd:get_hash("sha256", "base64")
print("sha256 hash in base64 format: " .. sha256_base64)

local base64_rsa_sig = "AwF2BbOvL6jA5DwmMAc9n6J2Cc8PI6Rj5W079+aKJcIEtPWRzHor0Bvc3aftGM3Jbgj6SXlIC3M3RYS7UZOnfiHKFNZgbxaNT5WwsWooK42ZkC8DBZl0p7OunBUKd5SciUo+TKilioeUkriN3L1Zl9hwi3HVDVqgVo3XXskwIftSqLSFlepTLTmOWj9Y93dp8J4D9RyLtNgFQBc0WB22tyJTsuY56mLcWe1AMF3LizB9OrbwjynF2u16xWlrJdugccz795fJBUV9aQSD+8S3KeqwQhoi8RK1uhD68aGCyaSpBq0NZ8COAkn7MXaF4POxrAAt8udfHM+PRfSOptcH/w=="

-- Get the public key to be used for signature verification.
local pubKey = chilkat.PublicKey.new()
local success = pubKey:load_from_file("rsaKeys/chilkat-rsa-2048.pem")
if not success then
    print(pubKey.last_error_text)
    return
end

local rsa = chilkat.Rsa.new()
success = rsa:use_public_key(pubKey)
if not success then
    print(rsa.last_error_text)
    return
end

-- Verify the hash against the signature.
rsa.encoding_mode = "base64"
success = rsa:verify_hash_enc(sha256_base64, "sha256", base64_rsa_sig)

if not success then
    print(rsa.last_error_text)
    print("Signature invalid.")
else
    print("Signature valid.")
end