Lua Requires Chilkat v11.0.0+

Validate Certificate using OCSP Protocol

See more Certificates Examples

Demonstrates how to validate a certificate (check the revoked status) using the OCSP protocol. Lua

local chilkat = require("chilkat")

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

-- This example will check the revoked status of a certificate loaded from a file.
local cert = chilkat.Cert.new()
local success = cert:load_from_file("qa_data/certs/google.crt")
if not success then
    print(cert.last_error_text)
    return
end

-- Get the cert's OCSP URL.
local ocspUrl = cert.ocsp_url

-- Build the JSON that will be the OCSP request.

-- Possible hash algorithms are sha1, sha256, sha384, sha512.
local hashAlg = "sha256"
local prng = chilkat.Prng.new()
local json = chilkat.JsonObject.new()
json.emit_compact = false
-- Read more about OCSP nonce lengths
json:update_string("extensions.ocspNonce", prng:gen_random(16, "base64"))
json.i = 0
json:update_string("request[i].cert.hashAlg", hashAlg)
json:update_string("request[i].cert.issuerNameHash", cert:hash_of("IssuerDN", hashAlg, "base64"))
json:update_string("request[i].cert.issuerKeyHash", cert:hash_of("IssuerPublicKey", hashAlg, "base64"))
json:update_string("request[i].cert.serialNumber", cert.serial_number)

print(json:emit())

-- Our OCSP request looks something like this:
-- {
--   "extensions": {
--     "ocspNonce": "qZDfbpO+nUxRzz6c/SPjE5QCAsPfpkQlRDxTnGl0gnxt7iXO"
--   },
--   "request": [
--     {
--       "cert": {
--         "hashAlg": "sha1",
--         "issuerNameHash": "9u2wY2IygZo19o11oJ0CShGqbK0=",
--         "issuerKeyHash": "d8K4UJpndnaxLcKG0IOgfqZ+uks=",
--         "serialNumber": "6175535D87BF94B6"
--       }
--     }
--   ]
-- }

local ocspRequest = chilkat.BinData.new()
local http = chilkat.Http.new()

-- Convert our JSON to a binary (ASN.1) OCSP request
success = http:create_ocsp_request(json, ocspRequest)
if not success then
    print(http.last_error_text)
    return
end

-- Send the OCSP request to the OCSP server
local resp = chilkat.HttpResponse.new()
success = http:http_bd("POST", ocspUrl, ocspRequest, "application/ocsp-request", resp)
if not success then
    print(http.last_error_text)
    return
end

-- Get the binary (ASN.1) OCSP reply
local ocspReply = chilkat.BinData.new()
resp:get_body_bd(ocspReply)

-- Convert the binary reply to JSON.
-- Also returns the overall OCSP response status.
local jsonReply = chilkat.JsonObject.new()
local ocspStatus = http:parse_ocsp_reply(ocspReply, jsonReply)

-- The ocspStatus can have one of these values:
-- -1:  The ARG1 does not contain a valid OCSP reply.
-- 0:  Successful - Response has valid confirmations..
-- 1: Malformed request - Illegal confirmation request.
-- 2: Internal error - Internal error in issuer.
-- 3: Try later -  Try again later.
-- 4: Not used - This value is never returned.
-- 5: Sig required - Must sign the request.
-- 6: Unauthorized - Request unauthorized.

if ocspStatus < 0 then
    print("Invalid OCSP reply.")
    return
end

print("Overall OCSP Response Status: " .. ocspStatus)

-- Let's examine the OCSP response (in JSON).
jsonReply.emit_compact = false
print(jsonReply:emit())

-- The JSON reply looks like this:
-- (Use the online tool at https://tools.chilkat.io/jsonParse.cshtml
-- to generate JSON parsing code.)

-- {
--   "responseStatus": 0,
--   "responseTypeOid": "1.3.6.1.5.5.7.48.1.1",
--   "responseTypeName": "ocspBasic",
--   "response": {
--     "responderIdChoice": "KeyHash",
--     "responderKeyHash": "d8K4UJpndnaxLcKG0IOgfqZ+uks=",
--     "dateTime": "20180803193937Z",
--     "cert": [
--       {
--         "hashOid": "1.3.14.3.2.26",
--         "hashAlg": "SHA-1",
--         "issuerNameHash": "9u2wY2IygZo19o11oJ0CShGqbK0=",
--         "issuerKeyHash": "d8K4UJpndnaxLcKG0IOgfqZ+uks=",
--         "serialNumber": "6175535D87BF94B6",
--         "status": 0,
--         "thisUpdate": "20180803193937Z",
--         "nextUpdate": "20180810193937Z"
--       }
--     ]
--   }
-- }
--

-- The certificate status:
local certStatus = -1
if jsonReply:has_member("response.cert[0].status") then
    certStatus = jsonReply:int_of("response.cert[0].status")
end

-- Possible certStatus values are:
-- -1: No status returned.
-- 0: Good
-- 1: Revoked
-- 2: Unknown.
print("Certificate Status: " .. certStatus)