annotate src/ur/openid.ur @ 27:f129ddee75f3

Some XRDS fixes; ignore query strings in naming endpoints for association purposes
author Adam Chlipala <adam@chlipala.net>
date Sun, 23 Jan 2011 17:40:42 -0500
parents ee97bc0e08fa
children f6b3fbf10dac
rev   line source
adam@6 1 val discoveryExpiry = 3600
adam@11 2 val nonceExpiry = 600
adam@11 3 val nonceSkew = 600
adam@6 4
adam@0 5 task initialize = fn () => OpenidFfi.init
adam@1 6
adam@6 7 table discoveries : { Identifier : string, Endpoint : string, Expires : time }
adam@6 8 PRIMARY KEY Identifier
adam@6 9
adam@17 10 fun eatFragment s =
adam@17 11 case String.split s #"#" of
adam@17 12 Some (s', _) => s'
adam@17 13 | _ => s
adam@17 14
adam@2 15 fun discover s =
adam@17 16 s <- return (eatFragment s);
adam@6 17 endpoint <- oneOrNoRowsE1 (SELECT (discoveries.Endpoint)
adam@6 18 FROM discoveries
adam@6 19 WHERE discoveries.Identifier = {[s]});
adam@6 20 case endpoint of
adam@6 21 Some ep => return (Some ep)
adam@6 22 | None =>
adam@6 23 r <- OpenidFfi.discover s;
adam@6 24 case r of
adam@6 25 None => return None
adam@6 26 | Some r =>
adam@6 27 tm <- now;
adam@6 28 dml (INSERT INTO discoveries (Identifier, Endpoint, Expires)
adam@6 29 VALUES ({[s]}, {[OpenidFfi.endpoint r]}, {[addSeconds tm discoveryExpiry]}));
adam@6 30 return (Some (OpenidFfi.endpoint r))
adam@3 31
adam@3 32 val createInputs =
adam@3 33 is <- OpenidFfi.createInputs;
adam@3 34 OpenidFfi.addInput is "openid.ns" "http://specs.openid.net/auth/2.0";
adam@3 35 return is
adam@3 36
adam@8 37 datatype association_type = HMAC_SHA1 | HMAC_SHA256
adam@8 38 datatype association_session_type = NoEncryption | DH_SHA1 | DH_SHA256
adam@13 39 datatype association_mode =
adam@13 40 Stateless
adam@13 41 | Stateful of {AssociationType : association_type,
adam@13 42 AssociationSessionType : association_session_type}
adam@8 43
adam@8 44 table associations : { Endpoint : string, Handle : string, Typ : serialized association_type, Key : string, Expires : time }
adam@3 45 PRIMARY KEY Endpoint
adam@3 46
adam@8 47 datatype association = Association of {Handle : string, Typ : association_type, Key : string}
adam@8 48 | AssError of string
adam@8 49 | AssAlternate of {Atype : association_type, Stype : association_session_type}
adam@3 50
adam@8 51 fun atype_show v =
adam@8 52 case v of
adam@8 53 HMAC_SHA1 => "HMAC-SHA1"
adam@8 54 | HMAC_SHA256 => "HMAC-SHA256"
adam@8 55
adam@8 56 val show_atype = mkShow atype_show
adam@8 57
adam@8 58 fun stype_show v =
adam@8 59 case v of
adam@8 60 NoEncryption => "no-encryption"
adam@8 61 | DH_SHA1 => "DH-SHA1"
adam@8 62 | DH_SHA256 => "DH-SHA256"
adam@8 63
adam@8 64 val show_stype = mkShow stype_show
adam@8 65
adam@8 66 fun atype_read s =
adam@8 67 case s of
adam@8 68 "HMAC-SHA1" => Some HMAC_SHA1
adam@8 69 | "HMAC-SHA256" => Some HMAC_SHA256
adam@8 70 | _ => None
adam@8 71
adam@8 72 val read_atype = mkRead' atype_read "association type"
adam@8 73
adam@8 74 fun stype_read s =
adam@8 75 case s of
adam@8 76 "no-encryption" => Some NoEncryption
adam@8 77 | "DH-SHA1" => Some DH_SHA1
adam@8 78 | "DH-SHA256" => Some DH_SHA256
adam@8 79 | _ => None
adam@8 80
adam@8 81 val read_stype = mkRead' stype_read "association session type"
adam@8 82
adam@8 83 fun atype_eq v1 v2 =
adam@8 84 case (v1, v2) of
adam@8 85 (HMAC_SHA1, HMAC_SHA1) => True
adam@8 86 | (HMAC_SHA256, HMAC_SHA256) => True
adam@8 87 | _ => False
adam@8 88
adam@8 89 val eq_atype = mkEq atype_eq
adam@8 90
adam@8 91 fun stype_eq v1 v2 =
adam@8 92 case (v1, v2) of
adam@8 93 (NoEncryption, NoEncryption) => True
adam@8 94 | (DH_SHA1, DH_SHA1) => True
adam@8 95 | (DH_SHA256, DH_SHA256) => True
adam@8 96 | _ => False
adam@8 97
adam@8 98 val eq_stype = mkEq stype_eq
adam@8 99
adam@8 100 fun errorResult atype stype os =
adam@8 101 case OpenidFfi.getOutput os "error" of
adam@8 102 Some v =>
adam@8 103 (case (OpenidFfi.getOutput os "error_code", OpenidFfi.getOutput os "assoc_type", OpenidFfi.getOutput os "session_type") of
adam@8 104 (Some "unsupported-type", at, st) => Some (AssAlternate {Atype = Option.get atype (Option.bind read at),
adam@8 105 Stype = Option.get stype (Option.bind read st)})
adam@8 106 | _ => Some (AssError ("OP error during association: " ^ v)))
adam@8 107 | None => None
adam@8 108
adam@27 109 fun eatQstring s =
adam@27 110 case String.split s #"?" of
adam@27 111 Some (s', _) => s'
adam@27 112 | _ => s
adam@27 113
adam@8 114 fun associateNoEncryption url atype =
adam@27 115 url <- return (eatQstring url);
adam@8 116 is <- createInputs;
adam@8 117 OpenidFfi.addInput is "openid.mode" "associate";
adam@8 118 OpenidFfi.addInput is "openid.assoc_type" (show atype);
adam@8 119 OpenidFfi.addInput is "openid.session_type" (show NoEncryption);
adam@8 120
adam@8 121 os <- OpenidFfi.direct url is;
adam@8 122 case errorResult atype NoEncryption os of
adam@8 123 Some v => return v
adam@8 124 | None =>
adam@8 125 case (OpenidFfi.getOutput os "assoc_handle", OpenidFfi.getOutput os "mac_key", OpenidFfi.getOutput os "expires_in") of
adam@8 126 (Some handle, Some key, Some expires) =>
adam@8 127 (case read expires of
adam@8 128 None => return (AssError "Invalid 'expires_in' field")
adam@8 129 | Some expires =>
adam@8 130 tm <- now;
adam@8 131 dml (INSERT INTO associations (Endpoint, Handle, Typ, Key, Expires)
adam@8 132 VALUES ({[url]}, {[handle]}, {[serialize atype]}, {[key]}, {[addSeconds tm expires]}));
adam@8 133 return (Association {Handle = handle, Typ = atype, Key = key}))
adam@8 134 | (None, _, _) => return (AssError "Missing assoc_handle")
adam@8 135 | (_, None, _) => return (AssError "Missing mac_key")
adam@8 136 | _ => return (AssError "Missing expires_in")
adam@8 137
adam@8 138 fun associateDh url atype stype =
adam@27 139 url <- return (eatQstring url);
adam@8 140 dh <- OpenidFfi.generate;
adam@8 141
adam@8 142 is <- createInputs;
adam@8 143 OpenidFfi.addInput is "openid.mode" "associate";
adam@8 144 OpenidFfi.addInput is "openid.assoc_type" (show atype);
adam@8 145 OpenidFfi.addInput is "openid.session_type" (show stype);
adam@8 146 OpenidFfi.addInput is "openid.dh_modulus" (OpenidFfi.modulus dh);
adam@8 147 OpenidFfi.addInput is "openid.dh_gen" (OpenidFfi.generator dh);
adam@8 148 OpenidFfi.addInput is "openid.dh_consumer_public" (OpenidFfi.public dh);
adam@8 149
adam@8 150 os <- OpenidFfi.direct url is;
adam@8 151 case errorResult atype stype os of
adam@8 152 Some v => return v
adam@8 153 | None =>
adam@8 154 case (OpenidFfi.getOutput os "assoc_handle", OpenidFfi.getOutput os "dh_server_public",
adam@8 155 OpenidFfi.getOutput os "enc_mac_key", OpenidFfi.getOutput os "expires_in") of
adam@8 156 (Some handle, Some pub, Some mac, Some expires) =>
adam@8 157 (case read expires of
adam@8 158 None => return (AssError "Invalid 'expires_in' field")
adam@8 159 | Some expires =>
adam@12 160 secret <- OpenidFfi.compute dh pub;
adam@12 161 digest <- return (case stype of
adam@12 162 DH_SHA1 => OpenidFfi.sha1 secret
adam@12 163 | DH_SHA256 => OpenidFfi.sha256 secret
adam@12 164 | _ => error <xml>Non-DH stype in associateDh</xml>);
adam@12 165 key <- return (OpenidFfi.xor mac digest);
adam@8 166 tm <- now;
adam@8 167 dml (INSERT INTO associations (Endpoint, Handle, Typ, Key, Expires)
adam@8 168 VALUES ({[url]}, {[handle]}, {[serialize atype]}, {[key]}, {[addSeconds tm expires]}));
adam@8 169 return (Association {Handle = handle, Typ = atype, Key = key}))
adam@8 170 | (None, _, _, _) => return (AssError "Missing assoc_handle")
adam@8 171 | (_, None, _, _) => return (AssError "Missing dh_server_public")
adam@8 172 | (_, _, None, _) => return (AssError "Missing enc_mac_key")
adam@8 173 | _ => return (AssError "Missing expires_in")
adam@8 174
adam@8 175 fun oldAssociation url =
adam@27 176 url <- return (eatQstring url);
adam@8 177 secret <- oneOrNoRows1 (SELECT associations.Handle, associations.Typ, associations.Key
adam@7 178 FROM associations
adam@7 179 WHERE associations.Endpoint = {[url]});
adam@3 180 case secret of
adam@8 181 Some r => return (Some (r -- #Typ ++ {Typ = deserialize r.Typ}))
adam@8 182 | None => return None
adam@8 183
adam@8 184 fun newAssociation url atype stype =
adam@8 185 case stype of
adam@8 186 NoEncryption => associateNoEncryption url atype
adam@8 187 | _ => associateDh url atype stype
adam@8 188
adam@8 189 fun association atype stype url =
adam@8 190 secret <- oldAssociation url;
adam@8 191 case secret of
adam@4 192 Some r => return (Association r)
adam@3 193 | None =>
adam@8 194 stype <- return (case (stype, String.isPrefix {Full = url, Prefix = "https://"}) of
adam@8 195 (NoEncryption, False) => DH_SHA256
adam@8 196 | _ => stype);
adam@8 197 r <- newAssociation url atype stype;
adam@8 198 case r of
adam@8 199 AssAlternate alt =>
adam@8 200 if alt.Atype = atype && alt.Stype = stype then
adam@8 201 return (AssError "Suggested new modes match old ones!")
adam@8 202 else
adam@12 203 debug "Renegotiating protocol";
adam@8 204 newAssociation url alt.Atype alt.Stype
adam@8 205 | v => return v
adam@4 206
adam@13 207 datatype handle_result = HandleOk of {Endpoint : string, Typ : association_type, Key : string} | NoAssociation of string | HandleError of string
adam@13 208
adam@13 209 datatype authentication = AuthenticatedAs of string | Canceled | Failure of string
adam@6 210
adam@6 211 fun verifyHandle os id =
adam@10 212 id' <- return (eatFragment id);
adam@10 213 ep <- discover id';
adam@6 214 case ep of
adam@10 215 None => return (HandleError ("Discovery failed on returned identifier: " ^ id'))
adam@6 216 | Some ep =>
adam@6 217 case OpenidFfi.getOutput os "openid.assoc_handle" of
adam@6 218 None => return (HandleError "Missing association handle in response")
adam@6 219 | Some handle =>
adam@8 220 assoc <- oldAssociation ep;
adam@6 221 case assoc of
adam@13 222 None => return (NoAssociation ep)
adam@8 223 | Some assoc =>
adam@6 224 if assoc.Handle <> handle then
adam@6 225 return (HandleError "Association handles don't match")
adam@6 226 else
adam@8 227 return (HandleOk {Endpoint = ep, Typ = assoc.Typ, Key = assoc.Key})
adam@6 228
adam@14 229 fun verifyStateless os ep id expectInvalidation =
adam@13 230 os' <- OpenidFfi.direct ep (OpenidFfi.remode os "check_authentication");
adam@13 231 case OpenidFfi.getOutput os' "error" of
adam@13 232 Some msg => return (Failure ("Failure confirming message contents with OP: " ^ msg))
adam@13 233 | None =>
adam@14 234 let
adam@14 235 fun finish () = case OpenidFfi.getOutput os' "is_valid" of
adam@14 236 Some "true" => return (AuthenticatedAs id)
adam@14 237 | _ => return (Failure "OP does not confirm message contents")
adam@14 238 in
adam@14 239 case OpenidFfi.getOutput os' "invalidate_handle" of
adam@14 240 None =>
adam@14 241 if expectInvalidation then
adam@14 242 return (Failure "Claimed invalidate_handle is not confirmed")
adam@14 243 else
adam@14 244 finish ()
adam@14 245 | Some handle =>
adam@14 246 dml (DELETE FROM associations
adam@14 247 WHERE Endpoint = {[ep]} AND Handle = {[handle]});
adam@14 248 finish ()
adam@14 249 end
adam@13 250
adam@6 251 table nonces : { Endpoint : string, Nonce : string, Expires : time }
adam@6 252 PRIMARY KEY (Endpoint, Nonce)
adam@6 253
adam@6 254 fun timeOfNonce s =
adam@6 255 case String.split s #"T" of
adam@6 256 None => None
adam@6 257 | Some (date, s) =>
adam@6 258 case String.split s #"Z" of
adam@6 259 None => None
adam@7 260 | Some (time, _) => readUtc (date ^ " " ^ time)
adam@6 261
adam@6 262 fun verifyNonce os ep =
adam@6 263 case OpenidFfi.getOutput os "openid.response_nonce" of
adam@6 264 None => return (Some "Missing nonce in OP response")
adam@6 265 | Some nonce =>
adam@6 266 case timeOfNonce nonce of
adam@6 267 None => return (Some "Invalid timestamp in nonce")
adam@6 268 | Some tm =>
adam@6 269 now <- now;
adam@9 270 if tm < addSeconds now (-nonceExpiry) then
adam@6 271 return (Some "Nonce timestamp is too old")
adam@9 272 else if tm > addSeconds now nonceSkew then
adam@11 273 return (Some "Nonce timestamp is too far in the future")
adam@6 274 else
adam@6 275 b <- oneRowE1 (SELECT COUNT( * ) > 0
adam@6 276 FROM nonces
adam@6 277 WHERE nonces.Endpoint = {[ep]}
adam@6 278 AND nonces.Nonce = {[nonce]});
adam@6 279
adam@6 280 if b then
adam@6 281 return (Some "Duplicate nonce")
adam@6 282 else
adam@6 283 dml (INSERT INTO nonces (Endpoint, Nonce, Expires)
adam@9 284 VALUES ({[ep]}, {[nonce]}, {[addSeconds now nonceExpiry]}));
adam@6 285 return None
adam@6 286
adam@8 287 fun verifySig os atype key =
adam@6 288 case OpenidFfi.getOutput os "openid.signed" of
adam@6 289 None => return (Some "Missing openid.signed in OP response")
adam@6 290 | Some signed =>
adam@6 291 case OpenidFfi.getOutput os "openid.sig" of
adam@6 292 None => return (Some "Missing openid.sig in OP response")
adam@6 293 | Some sign => let
adam@9 294 fun gatherNvps signed required acc =
adam@6 295 let
adam@6 296 val (this, next) =
adam@6 297 case String.split signed #"," of
adam@6 298 None => (signed, None)
adam@6 299 | Some (this, next) => (this, Some next)
adam@6 300 in
adam@6 301 case OpenidFfi.getOutput os ("openid." ^ this) of
adam@6 302 None => None
adam@6 303 | Some value =>
adam@6 304 let
adam@9 305 val required = List.filter (fn other => other <> this) required
adam@6 306 val acc = acc ^ this ^ ":" ^ value ^ "\n"
adam@6 307 in
adam@6 308 case next of
adam@9 309 None => Some (required, acc)
adam@9 310 | Some next => gatherNvps next required acc
adam@6 311 end
adam@6 312 end
adam@6 313 in
adam@9 314 case gatherNvps signed ("op_endpoint" :: "return_to" :: "response_nonce" :: "assoc_handle" :: "claimed_id" :: "identity" :: []) "" of
adam@6 315 None => return (Some "openid.signed mentions missing field")
adam@9 316 | Some ([], nvps) =>
adam@6 317 let
adam@8 318 val sign' = case atype of
adam@12 319 HMAC_SHA256 => OpenidFfi.hmac_sha256 key nvps
adam@12 320 | HMAC_SHA1 => OpenidFfi.hmac_sha1 key nvps
adam@6 321 in
adam@6 322 if sign' = sign then
adam@6 323 return None
adam@6 324 else
adam@6 325 return (Some "Signatures don't match")
adam@6 326 end
adam@9 327 | Some (left, _) => return (Some ("openid.signed is missing required fields: " ^ show left))
adam@6 328 end
adam@6 329
adam@10 330 fun authenticate after r =
adam@10 331 let
adam@12 332 fun returnTo (qs : option queryString) =
adam@10 333 case qs of
adam@10 334 None => after (Failure "Empty query string for OpenID callback")
adam@10 335 | Some qs =>
adam@10 336 os <- OpenidFfi.indirect qs;
adam@10 337 case OpenidFfi.getOutput os "openid.error" of
adam@13 338 Some v => after (Failure ("Authentication failed: " ^ v))
adam@10 339 | None =>
adam@10 340 case OpenidFfi.getOutput os "openid.mode" of
adam@10 341 None => after (Failure "No openid.mode in response")
adam@10 342 | Some mode =>
adam@10 343 case mode of
adam@10 344 "cancel" => after Canceled
adam@10 345 | "id_res" =>
adam@10 346 (case OpenidFfi.getOutput os "openid.claimed_id" of
adam@10 347 None => after (Failure "Missing identity in OP response")
adam@10 348 | Some id =>
adam@13 349 errO <- verifyReturnTo os;
adam@6 350 case errO of
adam@13 351 Some s => after (Failure s)
adam@13 352 | None =>
adam@13 353 errO <- verifyHandle os id;
adam@6 354 case errO of
adam@13 355 HandleError s => after (Failure s)
adam@13 356 | NoAssociation ep =>
adam@14 357 r <- verifyStateless os ep id False;
adam@13 358 after r
adam@13 359 | HandleOk {Endpoint = ep, Typ = atype, Key = key} =>
adam@14 360 case OpenidFfi.getOutput os "openid.invalidate_handle" of
adam@14 361 Some _ =>
adam@14 362 r <- verifyStateless os ep id True;
adam@14 363 after r
adam@10 364 | None =>
adam@14 365 errO <- verifyNonce os ep;
adam@10 366 case errO of
adam@10 367 Some s => after (Failure s)
adam@14 368 | None =>
adam@14 369 errO <- verifySig os atype key;
adam@14 370 case errO of
adam@14 371 Some s => after (Failure s)
adam@14 372 | None => after (AuthenticatedAs id))
adam@10 373 | _ => after (Failure ("Unexpected openid.mode: " ^ mode))
adam@4 374
adam@12 375 and verifyReturnTo os =
adam@10 376 case OpenidFfi.getOutput os "openid.return_to" of
adam@10 377 None => return (Some "Missing return_to in OP response")
adam@10 378 | Some rt =>
adam@12 379 if rt <> show (effectfulUrl returnTo) then
adam@10 380 return (Some "Wrong return_to in OP response")
adam@10 381 else
adam@10 382 return None
adam@15 383
adam@15 384 val realmString = case r.Realm of
adam@15 385 None => ""
adam@15 386 | Some realm => "&openid.realm=" ^ realm
adam@10 387 in
adam@10 388 dy <- discover r.Identifier;
adam@10 389 case dy of
adam@10 390 None => return "Discovery failed"
adam@10 391 | Some dy =>
adam@27 392 let
adam@27 393 val begin = case String.index dy #"?" of
adam@27 394 None => "?"
adam@27 395 | Some _ => "&"
adam@27 396 in
adam@27 397 case r.Association of
adam@27 398 Stateless =>
adam@27 399 redirect (bless (dy ^ begin ^ "openid.ns=http://specs.openid.net/auth/2.0&openid.mode=checkid_setup"
adam@26 400 ^ "&openid.claimed_id=http://specs.openid.net/auth/2.0/identifier_select"
adam@17 401 ^ "&openid.identity=http://specs.openid.net/auth/2.0/identifier_select&openid.assoc_handle="
adam@27 402 ^ "&openid.return_to=" ^ show (effectfulUrl returnTo) ^ realmString))
adam@27 403 | Stateful ar =>
adam@27 404 assoc <- association ar.AssociationType ar.AssociationSessionType dy;
adam@27 405 case assoc of
adam@27 406 AssError msg => return ("Association failure: " ^ msg)
adam@27 407 | AssAlternate _ => return "Association failure: server didn't accept its own alternate association modes"
adam@27 408 | Association assoc =>
adam@27 409 redirect (bless (dy ^ begin ^ "openid.ns=http://specs.openid.net/auth/2.0&openid.mode=checkid_setup"
adam@27 410 ^ "&openid.claimed_id=http://specs.openid.net/auth/2.0/identifier_select"
adam@27 411 ^ "&openid.identity=http://specs.openid.net/auth/2.0/identifier_select&openid.assoc_handle="
adam@27 412 ^ assoc.Handle ^ "&openid.return_to=" ^ show (effectfulUrl returnTo) ^ realmString))
adam@27 413 end
adam@10 414 end
adam@6 415
adam@22 416 task periodic 60 = fn () =>
adam@22 417 dml (DELETE FROM discoveries WHERE Expires < CURRENT_TIMESTAMP);
adam@22 418 dml (DELETE FROM associations WHERE Expires < CURRENT_TIMESTAMP);
adam@22 419 dml (DELETE FROM nonces WHERE Expires < CURRENT_TIMESTAMP)