Matitaweb: secure SHA-256 encryption for passwords.

[helm.git] / matitaB / matita / matitaAuthentication.ml

diff --git a/matitaB/matita/matitaAuthentication.ml b/matitaB/matita/matitaAuthentication.ml
index 7ae548058abea4efed9272e96645776ec3b03cc4..a3704ee4eb3056b16287f74f2d16847842afafc5 100644 (file)
--- a/matitaB/matita/matitaAuthentication.ml
+++ b/matitaB/matita/matitaAuthentication.ml
@@ -27,8 +27,8 @@ type session_id = Uuidm.t
 
 type matita_file = MatitaFilesystem.matita_flag * string
 
-(* user table: user id, (password, optional session id) *)
-type user = string * (string * session_id option)
+(* user table: user id, (salt, encrypted password, optional session id) *)
+type user = string * (string * string * session_id option)
 
 let user_tbl = (ref [] : user list ref)
 
@@ -38,6 +38,7 @@ type session = session_id * (string * MatitaEngine.status * MatitaEngine.status
 let session_tbl = (ref [] : session list ref)
 
 exception UsernameCollision of string
+exception InvalidPassword
 
 let lookup_user uid = List.assoc uid !user_tbl
 
@@ -48,10 +49,10 @@ let get_users () = List.map fst !user_tbl
 let create_session uid =
   let status = new MatitaEngine.status (Some uid) "cic:/matita" in
   let history = [status] in
-  let pw,sid = List.assoc uid !user_tbl in
+  let salt,pw,sid = List.assoc uid !user_tbl in
   let clean_utbl = List.remove_assoc uid !user_tbl in
   let new_session = Uuidm.create `V4 in
-  user_tbl := (uid,(pw,Some new_session))::clean_utbl;
+  user_tbl := (uid,(salt,pw,Some new_session))::clean_utbl;
   let clean_stbl = match sid with
     | Some sid' -> 
        List.remove_assoc sid' !session_tbl
@@ -83,8 +84,8 @@ let set_history sid hist =
 
 let logout_user sid =
   let uid,st,hist = List.assoc sid !session_tbl in
-  let pw,_ = List.assoc uid !user_tbl in
-  user_tbl := (uid,(pw,None))::List.remove_assoc uid !user_tbl;
+  let salt,pw,_ = List.assoc uid !user_tbl in
+  user_tbl := (uid,(salt,pw,None))::List.remove_assoc uid !user_tbl;
   session_tbl := List.remove_assoc sid !session_tbl
 ;;
 
@@ -101,7 +102,7 @@ let config_path () =
 ;;
 
 let serialize () =
-  let clean_utbl = List.map (fun (uid,(pw,_)) -> uid,(pw,None)) !user_tbl in
+  let clean_utbl = List.map (fun (uid,(salt,pw,_)) -> uid,(salt,pw,None)) !user_tbl in
   let utbl_ch = open_out (config_path () ^ "/usertable.dump") in
   Marshal.to_channel utbl_ch clean_utbl [];
   close_out utbl_ch;
@@ -157,11 +158,43 @@ let add_user uid pw =
     raise (UsernameCollision uid)
   with Not_found -> 
     let ft = MatitaFilesystem.checkout uid in
-    user_tbl := (uid,(pw,None))::!user_tbl;
+    (* use a 8 byte salt *)
+    let salt = Cryptokit.Random.string Cryptokit.Random.secure_rng 8 in
+    let sha256 = Cryptokit.Hash.sha256 () in
+    sha256#add_string (salt ^ pw);
+    let crypto_pw = sha256#result in
+    user_tbl := (uid,(salt,crypto_pw,None))::!user_tbl;
     write_ft uid ft;
     serialize ()
 ;;
 
+let add_user_no_checkout uid pw =
+  try
+    let _ = lookup_user uid in
+    raise (UsernameCollision uid)
+  with Not_found -> 
+    (* use a 8 byte salt *)
+    let salt = Cryptokit.Random.string Cryptokit.Random.secure_rng 8 in
+    let sha256 = Cryptokit.Hash.sha256 () in
+    sha256#add_string (salt ^ pw);
+    let crypto_pw = sha256#result in
+    sha256#wipe;
+    user_tbl := (uid,(salt,crypto_pw,None))::!user_tbl;
+    serialize ()
+;;
+
+let check_pw uid pw =
+  try
+    let salt,crypto_pw,_ = lookup_user uid in
+    let sha256 = Cryptokit.Hash.sha256 () in
+    sha256#add_string (salt ^ pw);
+    let computed_pw = sha256#result in
+    sha256#wipe;
+    if crypto_pw <> computed_pw 
+      then (prerr_endline ("password " ^ pw ^ " incorrect"); raise InvalidPassword)
+  with Not_found _ -> raise InvalidPassword
+;;
+
 let reset () =
   user_tbl := [];
   session_tbl := [];