1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
|
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}
--------------------------------------------------------------------------------
-- | Get a certificate from Let's Encrypt using the ACME protocol.
--
-- https://github.com/ietf-wg-acme/acme/blob/master/draft-ietf-acme-acme.md
module Main where
import Control.Concurrent (threadDelay)
import Control.Lens hiding ((.=))
import Control.Monad
import Control.Monad.RWS.Strict
import Crypto.Number.Serialize (i2osp)
import Data.Aeson (ToJSON (..), Value, encode, object,
(.=))
import Data.Aeson.Lens hiding (key)
import qualified Data.Aeson.Lens as JSON
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
import qualified Data.ByteString.Base64.URL as Base64
import qualified Data.ByteString.Char8 as BC
import qualified Data.ByteString.Lazy as LB
import qualified Data.ByteString.Lazy.Char8 as LC
import Data.Coerce
import Data.Digest.Pure.SHA (bytestringDigest, sha256)
import Data.Maybe
import qualified Data.Text as T
import Data.Text.Encoding (decodeUtf8, encodeUtf8)
import Network.Wreq (Response, checkStatus, defaults,
responseBody, responseHeader,
responseStatus, statusCode,
statusMessage)
import qualified Network.Wreq.Session as WS
import OpenSSL
import OpenSSL.EVP.Digest
import OpenSSL.EVP.PKey
import OpenSSL.EVP.Sign
import OpenSSL.PEM
import OpenSSL.RSA
import Options.Applicative hiding (header)
import qualified Options.Applicative as Opt
import System.Directory
import System.Exit
import System.Process (readProcess)
directoryUrl :: String
directoryUrl = "https://acme-v01.api.letsencrypt.org/directory"
main :: IO ()
main = execParser opts >>= go
where
opts = info (helper <*> cmdopts) (fullDesc <> progDesc detailedDescription <> Opt.header "Let's Encrypt! ACME client")
detailedDescription = "This is a work in progress."
data CmdOpts = CmdOpts {
optKeyFile :: String,
optDomain :: String,
optChallengeDir :: String,
optEmail :: Maybe String,
optTerms :: Maybe String
}
defaultTerms :: String
defaultTerms = "https://letsencrypt.org/documents/LE-SA-v1.0.1-July-27-2015.pdf"
cmdopts :: Parser CmdOpts
cmdopts = CmdOpts <$> strOption (long "key" <> metavar "FILE" <> help "filename of your private RSA key")
<*> strOption (long "domain" <> metavar "DOMAIN" <> help "the domain name to certify")
<*> strOption (long "dir" <> metavar "DIR" <> help "output directory for ACME challenges")
<*> optional (strOption (long "email" <> metavar "ADDRESS" <> help "an email address with which to register an account"))
<*> optional (strOption (long "terms" <> metavar "URL" <> help "the terms param of the registration request"))
genKey :: String -> IO ()
genKey privKeyFile = void $ readProcess "openssl" (words "genrsa -out" ++ [privKeyFile, "4096"]) ""
genReq :: String -> String -> String -> IO ()
genReq privKeyFile domain out = void $ readProcess "openssl" (args privKeyFile domain out) ""
where
args k d o = words "req -new -sha256 -outform DER -key" ++ [k, "-subj", "/CN=" ++ d, "-out", o]
data Keys = Keys SomeKeyPair RSAPubKey
readKeys :: String -> IO Keys
readKeys privKeyFile = do
priv <- readFile privKeyFile >>= flip readPrivateKey PwTTY
pub <- rsaCopyPublic $ fromMaybe (error "Error: failed to parse RSA key.") (toKeyPair priv :: Maybe RSAKeyPair)
return $ Keys priv pub
go :: CmdOpts -> IO ()
go (CmdOpts privKeyFile domain challengeDir email termOverride) = do
doesFileExist privKeyFile >>= flip unless (genKey privKeyFile)
let domainKeyFile = domain </> "rsa.key"
domainCSRFile = domain </> "csr.der"
domainCertFile = domain </> "cert.der"
doesDirectoryExist domain >>= flip unless (createDirectory domain)
doesFileExist domainKeyFile >>= flip unless (genKey domainKeyFile)
doesFileExist domainCSRFile >>= flip unless (genReq domainKeyFile domain domainCSRFile)
csrData <- B.readFile domainCSRFile
keys@(Keys _ pub) <- readKeys privKeyFile
let terms = fromMaybe defaultTerms termOverride
-- Create user account
runACME directoryUrl keys $ do
forM_ email $ register terms >=> statusReport
r <- challengeRequest domain >>= statusReport
let
httpChallenge :: (Value -> Const (Endo s) Value) -> Response LC.ByteString -> Const (Endo s) (Response LC.ByteString)
httpChallenge = responseBody . JSON.key "challenges" . to universe . traverse . (filtered . has $ ix "type" . only "http-01")
token = r ^?! httpChallenge . JSON.key "token" . _String . to encodeUtf8
crUri = r ^?! httpChallenge . JSON.key "uri" . _String . to T.unpack
thumb = thumbprint (JWK (rsaE pub) "RSA" (rsaN pub))
thumbtoken = toStrict (LB.fromChunks [token, ".", thumb])
liftIO $ do
mapM_ print $ r ^@.. httpChallenge . members
print $ encodeOrdered (JWK (rsaE pub) "RSA" (rsaN pub))
-- liftIO $ LC.writeFile (challengeDir </> BC.unpack token) p
liftIO $ BC.writeFile (challengeDir </> BC.unpack token) thumbtoken
-- Wait for challenge validation
-- TODO: first hit the local server to test whether this is valid
r <- pollChallenge crUri thumbtoken >>= statusReport
if r ^. responseStatus . statusCode . to isSuccess then do
liftIO $ void exitSuccess
-- Send a CSR and get a certificate
void $ saveCert csrData domainCertFile >>= statusReport
else liftIO $ putStrLn "Error"
where
a </> b = a ++ "/" ++ b
isSuccess n = n >= 200 && n <= 300
saveCert :: (MonadReader Env m, MonadState Nonce m, MonadIO m) => ByteString -> FilePath -> m (Response LC.ByteString)
saveCert input output = do
r <- sendPayload _newCert (csr input)
liftIO $ LC.writeFile output $ r ^. responseBody
return r
pollChallenge :: (MonadReader Env m, MonadState Nonce m, MonadIO m) => String -> ByteString -> m (Response LC.ByteString)
pollChallenge crUri thumbtoken = loop
where
loop = do
liftIO . threadDelay $ 2000 * 1000
liftIO $ putStrLn "polling..."
r <- sendPayload (const crUri) (challenge thumbtoken) >>= statusReport
let status = r ^? responseBody . JSON.key "status" . _String
if status == Just "pending"
then do
liftIO . print $ r ^. responseBody
liftIO . print $ r ^? responseBody . JSON.key "keyAuthorization" . _String
liftIO . threadDelay $ 2000 * 1000
loop
else do
liftIO $ putStrLn "done polling."
liftIO $ print r
return r
data Env = Env { getDir :: Directory, getKeys :: Keys, getSession :: WS.Session }
type ACME a = RWST Env () Nonce IO a
runACME :: String -> Keys -> ACME a -> IO a
runACME url keys f = WS.withSession $ \sess -> do
Just (dir, nonce) <- getDirectory sess url
fst <$> evalRWST f (Env dir keys sess) nonce
data Directory = Directory {
_newCert :: String,
_newAuthz :: String,
_revokeCert :: String,
_newReg :: String
}
newtype Nonce = Nonce String
testRegister :: String -> IO (Response LC.ByteString)
testRegister email = runTest (register defaultTerms email) >>= statusReport
runTest :: ACME b -> IO b
runTest t = readKeys "rsa.key" >>= flip (runACME directoryUrl) t
testCR :: IO (Response LC.ByteString)
testCR = runTest $ challengeRequest "fifty.childrenofmay.org"
getDirectory :: WS.Session -> String -> IO (Maybe (Directory, Nonce))
getDirectory sess url = do
r <- WS.get sess url
let nonce = r ^? responseHeader "Replay-Nonce" . to (Nonce . T.unpack . decodeUtf8)
k x = r ^? responseBody . JSON.key x . _String . to T.unpack
return $ (,) <$> (Directory <$> k "new-cert" <*> k "new-authz" <*> k "revoke-cert" <*> k "new-reg") <*> nonce
register :: String -> String -> ACME (Response LC.ByteString)
register terms email = sendPayload _newReg (registration email terms)
challengeRequest :: (MonadIO m, MonadState Nonce m, MonadReader Env m) => String -> m (Response LC.ByteString)
challengeRequest domain = sendPayload _newAuthz (authz domain)
statusLine :: Response body -> String
statusLine r = (r ^. responseStatus . statusCode . to show) ++ " " ++ r ^. responseStatus . statusMessage . to (T.unpack . decodeUtf8)
statusReport :: MonadIO m => Response body -> m (Response body)
statusReport r = do
liftIO $ putStrLn $ statusLine r
return r
sendPayload :: (MonadIO m, MonadState Nonce m, MonadReader Env m) => (Directory -> String) -> ByteString -> m (Response LC.ByteString)
sendPayload reqType payload = do
keys <- asks getKeys
dir <- asks getDir
nonce <- gets coerce
signed <- liftIO $ signPayload keys nonce payload
post (reqType dir) signed
-- post :: (MonadReader Env m, MonadState Nonce m, MonadIO m, Postable a) => String -> a -> m (Response LC.ByteString)
post url payload = do
sess <- asks getSession
r <- liftIO $ WS.postWith noStatusCheck sess url payload
put $ r ^?! responseHeader "Replay-Nonce" . to (Nonce . T.unpack . decodeUtf8)
return r
where
noStatusCheck = defaults & checkStatus .~ Just nullChecker
nullChecker _ _ _ = Nothing
--------------------------------------------------------------------------------
-- | Sign return a payload with a nonce-protected header.
signPayload :: Keys -> String -> ByteString -> IO LC.ByteString
signPayload (Keys priv pub) nonce_ payload = withOpenSSL $ do
let protected = b64 (header pub nonce_)
Just dig <- getDigestByName "SHA256"
sig <- b64 <$> signBS dig priv (B.concat [protected, ".", payload])
return $ encode (Request (header' pub) protected payload sig)
--------------------------------------------------------------------------------
-- | Base64URL encoding of Integer with padding '=' removed.
b64i :: Integer -> ByteString
b64i = b64 . i2osp
b64 :: ByteString -> ByteString
b64 = B.takeWhile (/= 61) . Base64.encode
toStrict :: LB.ByteString -> ByteString
toStrict = B.concat . LB.toChunks
header' :: RSAKey k => k -> Header
header' key = Header "RS256" (JWK (rsaE key) "RSA" (rsaN key)) Nothing
header :: RSAKey k => k -> String -> ByteString
header key nonce = (toStrict . encode)
(Header "RS256" (JWK (rsaE key) "RSA" (rsaN key)) (Just nonce))
-- | Registration payload to sign with user key.
registration :: String -> String -> ByteString
registration emailAddr terms = (b64 . toStrict . encode) (Reg emailAddr terms)
-- | Challenge request payload to sign with user key.
authz :: String -> ByteString
authz = b64. toStrict . encode . Authz
-- | Challenge response payload to sign with user key.
challenge :: ByteString -> ByteString
challenge = b64 . toStrict . encode . Challenge . BC.unpack
-- | CSR request payload to sign with user key.
csr :: ByteString -> ByteString
csr = b64 . toStrict . encode . CSR . b64
thumbprint :: JWK -> ByteString
thumbprint = b64 . toStrict . bytestringDigest . sha256 . encodeOrdered
-- | There is an `encodePretty'` in `aeson-pretty`, but do it by hand here.
encodeOrdered :: JWK -> LB.ByteString
encodeOrdered JWK{..} = LC.pack $
"{\"e\":\"" ++ hE' ++ "\",\"kty\":\"" ++ hKty ++ "\",\"n\":\"" ++ hN' ++ "\"}"
where
hE' = BC.unpack (b64i hE)
hN' = BC.unpack (b64i hN)
--------------------------------------------------------------------------------
data Header = Header
{ hAlg :: String
, hJwk :: JWK
, hNonce :: Maybe String
}
deriving Show
data JWK = JWK
{ hE :: Integer
, hKty :: String
, hN :: Integer
}
deriving Show
instance ToJSON Header where
toJSON Header{..} = object $
[ "alg" .= hAlg
, "jwk" .= toJSON hJwk
] ++ maybeToList (("nonce" .=) <$> hNonce)
instance ToJSON JWK where
toJSON JWK{..} = object
[ "e" .= decodeUtf8 (b64i hE)
, "kty" .= hKty
, "n" .= decodeUtf8 (b64i hN)
]
data Reg = Reg
{ rMail :: String
, rAgreement :: String
}
deriving Show
instance ToJSON Reg where
toJSON Reg{..} = object
[ "resource" .= ("new-reg" :: String)
, "contact" .= ["mailto:" ++ rMail]
, "agreement" .= rAgreement
]
data Request = Request
{ rHeader :: Header
, rProtected :: ByteString
, rPayload :: ByteString
, rSignature :: ByteString
}
deriving Show
instance ToJSON Request where
toJSON Request{..} = object
[ "header" .= toJSON rHeader
, "protected" .= decodeUtf8 rProtected
, "payload" .= decodeUtf8 rPayload
, "signature" .= decodeUtf8 rSignature
]
data Authz = Authz
{ aDomain :: String
}
instance ToJSON Authz where
toJSON Authz{..} = object
[ "resource" .= ("new-authz" :: String)
, "identifier" .= object
[ "type" .= ("dns" :: String)
, "value" .= aDomain
]
]
data Challenge = Challenge
{ cKeyAuth :: String
}
instance ToJSON Challenge where
toJSON Challenge{..} = object
[ "resource" .= ("challenge" :: String)
, "keyAuthorization" .= cKeyAuth
]
data CSR = CSR ByteString
deriving Show
instance ToJSON CSR where
toJSON (CSR s) = object
[ "resource" .= ("new-cert" :: String)
, "csr" .= decodeUtf8 s
]
|