Make Stylistic Changes in order to conform to guidelines:

1. Remove trailing whitespace
2. Remove Macros
3. Handle all erroneous response codes the same way
4. Add specs
Also don't return nonces anymore when the http response is negative.

src/ejabberd_acme.erl

@@ -1,7 +1,7 @@
 -module (ejabberd_acme).
 
 -export([ scenario/3
-        , scenario0/0
+        , scenario0/1
         , directory/1
         , get_account/3
         , new_account/4
@@ -14,12 +14,15 @@
 -include_lib("public_key/include/public_key.hrl").
 
 -define(REQUEST_TIMEOUT, 5000). % 5 seconds.
--define(DIRURL, "directory").
--define(REGURL, "/acme/reg/").
-
--define(DEFAULT_KEY_FILE, "private_key_temporary").
 
 
+-type nonce() :: string().
+-type url() :: string().
+-type proplist() :: [{_, _}].
+-type jws() :: map().
+
+-spec directory(url()) ->
+  {ok, map(), nonce()} | {error, _}.
 directory(DirURL) ->
   Options = [],
   HttpOptions = [{timeout, ?REQUEST_TIMEOUT}],
@@ -34,21 +37,22 @@ directory(DirURL) ->
       %% Return Map of Directories
       NewDirs = maps:from_list(StrDirectories),
       {ok, NewDirs, Nonce};
-    {ok, {{_, Code, _}, Head, _Body}} ->
+    {ok, {{_, Code, _}, _Head, _Body}} ->
       ?ERROR_MSG("Got unexpected status code from <~s>: ~B",
         [DirURL, Code]),
-      Nonce = get_nonce(Head),
-      {error, unexpected_code, Nonce};
+      {error, unexpected_code};
     {error, Reason} ->
       ?ERROR_MSG("Error requesting directory from <~s>: ~p",
         [DirURL, Reason]),
       {error, Reason}
   end.
 
+-spec new_account(url(), jose_jwk:key(), proplist(), nonce()) ->
+  {ok, {url(), proplist()}, nonce()} | {error, _}.
 new_account(NewAccURl, PrivateKey, Req, Nonce) ->
   %% Make the request body
   ReqBody = jiffy:encode({[{ <<"resource">>, <<"new-reg">>}] ++ Req}),
-  {_, SignedBody} = sign_json_jose(PrivateKey, ReqBody, NewAccURl, Nonce),
+  {_, SignedBody} = sign_json_jose(PrivateKey, ReqBody, Nonce),
   %% Encode the Signed body with jiffy
   FinalBody = jiffy:encode(SignedBody),
   Options = [],
@@ -58,30 +62,26 @@ new_account(NewAccURl, PrivateKey, Req, Nonce) ->
     {ok, {{_, Code, _}, Head, Body}} when Code >= 200, Code =< 299 ->
       %% Decode the json string
       {Return} = jiffy:decode(Body),
-      TOSUrl = get_TOS(Head),
+      TOSUrl = get_tos(Head),
       % Find and save the replay nonce
       NewNonce = get_nonce(Head),
       {ok, {TOSUrl, Return}, NewNonce};
-    {ok, {{_, 409 = Code, _}, Head, Body}} ->
-      ?ERROR_MSG("Got status code: ~B from <~s>, Body: ~s",
-        [NewAccURl, Code, Body]),
-      NewNonce = get_nonce(Head),
-      {error, key_in_use, NewNonce};
-    {ok, {{_, Code, _}, Head, Body}} ->
+    {ok, {{_, Code, _}, _Head, Body}} ->
       ?ERROR_MSG("Got unexpected status code from <~s>: ~B, Body: ~s",
         [NewAccURl, Code, Body]),
-      NewNonce = get_nonce(Head),
-      {error, unexpected_code, NewNonce};
+      {error, unexpected_code};
     {error, Reason} ->
       ?ERROR_MSG("Error requesting directory from <~s>: ~p",
         [NewAccURl, Reason]),
-      {error, Reason, Nonce}
+      {error, Reason}
   end.
 
+-spec update_account(url(), jose_jwk:key(), proplist(), nonce()) ->
+  {ok, proplist(), nonce()} | {error, _}.
 update_account(AccURl, PrivateKey, Req, Nonce) ->
   %% Make the request body
   ReqBody = jiffy:encode({[{ <<"resource">>, <<"reg">>}] ++ Req}),
-  {_, SignedBody} = sign_json_jose(PrivateKey, ReqBody, AccURl, Nonce),
+  {_, SignedBody} = sign_json_jose(PrivateKey, ReqBody, Nonce),
   %% Encode the Signed body with jiffy
   FinalBody = jiffy:encode(SignedBody),
   Options = [],
@@ -94,25 +94,23 @@ update_account(AccURl, PrivateKey, Req, Nonce) ->
       % Find and save the replay nonce
       NewNonce = get_nonce(Head),
       {ok, Return, NewNonce};
-    {ok, {{_, Code, _}, Head, Body}} ->
+    {ok, {{_, Code, _}, _Head, Body}} ->
       ?ERROR_MSG("Got unexpected status code from <~s>: ~B, Body: ~s",
         [AccURl, Code, Body]),
-      NewNonce = get_nonce(Head),
-      {error, unexpected_code, NewNonce};
+      {error, unexpected_code};
     {error, Reason} ->
       ?ERROR_MSG("Error requesting directory from <~s>: ~p",
         [AccURl, Reason]),
-      {error, Reason, Nonce}
+      {error, Reason}
   end.
 
-
+-spec get_account(url(), jose_jwk:key(), nonce()) ->
+  {ok, {url(), proplist()}, nonce()} | {error, _}.
 get_account(AccURl, PrivateKey, Nonce) ->
   %% Make the request body
-  ReqBody = jiffy:encode({[
-      { <<"resource">>, <<"reg">>}
-  ]}),
+  ReqBody = jiffy:encode({[{<<"resource">>, <<"reg">>}]}),
   %% Jose Sign
-  {_, SignedBody} = sign_json_jose(PrivateKey, ReqBody, AccURl, Nonce),
+  {_, SignedBody} = sign_json_jose(PrivateKey, ReqBody, Nonce),
   %% Encode the Signed body with jiffy
   FinalBody = jiffy:encode(SignedBody),
   Options = [],
@@ -122,33 +120,35 @@ get_account(AccURl, PrivateKey, Nonce) ->
     {ok, {{_, Code, _}, Head, Body}} when Code >= 200, Code =< 299 ->
       %% Decode the json string
       {Return} = jiffy:decode(Body),
-      TOSUrl = get_TOS(Head),
+      TOSUrl = get_tos(Head),
       % Find and save the replay nonce
       NewNonce = get_nonce(Head),
       {ok, {TOSUrl, Return}, NewNonce};
-    {ok, {{_, Code, _}, Head, Body}} ->
+    {ok, {{_, Code, _}, _Head, Body}} ->
       ?ERROR_MSG("Got unexpected status code from <~s>: ~B, Head: ~s",
         [AccURl, Code, Body]),
-        NewNonce = get_nonce(Head),
-      {error, unexpected_code, NewNonce};
+      {error, unexpected_code};
     {error, Reason} ->
       ?ERROR_MSG("Error requesting directory from <~s>: ~p",
         [AccURl, Reason]),
-      {error, Reason, Nonce}
+      {error, Reason}
   end.
 
 
 %%
 %% Useful funs
 %%
-
+-spec get_nonce(proplist()) -> nonce() | 'none'.
 get_nonce(Head) ->
-  {"replay-nonce", Nonce} = proplists:lookup("replay-nonce", Head),
-  Nonce.
+  case proplists:lookup("replay-nonce", Head) of
+    {"replay-nonce", Nonce} -> Nonce;
+    none -> none
+  end.
 
 %% Very bad way to extract this
 %% TODO: Find a better way
-get_TOS(Head) ->
+-spec get_tos(proplist()) -> url() | 'none'.
+get_tos(Head) ->
   try
     [{_, Link}] = [{K, V} || {K, V} <- Head,
         K =:= "link" andalso lists:suffix("\"terms-of-service\"", V)],
@@ -157,16 +157,15 @@ get_TOS(Head) ->
     string:strip(Link2, right, $>)
   catch
     _:_ ->
-      no_tos
+      none
   end.
 
-
-sign_json_jose(Key, Json, Url, Nonce) ->
+-spec sign_json_jose(jose_jwk:key(), string(), nonce()) -> jws().
+sign_json_jose(Key, Json, Nonce) ->
     % Generate a public key
     PubKey = jose_jwk:to_public(Key),
     {_, BinaryPubKey} = jose_jwk:to_binary(PubKey),
     PubKeyJson = jiffy:decode(BinaryPubKey),
-    
     % Jws object containing the algorithm
     %% TODO: Dont hardcode the alg
     JwsObj = jose_jws:from(
@@ -185,17 +184,16 @@ sign_json_jose(Key, Json, Url, Nonce) ->
 
 %% A typical acme workflow
 scenario(CAUrl, AccId, PrivateKey) ->
-  
-  DirURL = CAUrl ++ "/" ++ ?DIRURL,
+  DirURL = CAUrl ++ "/directory",
   {ok, Dirs, Nonce0} = directory(DirURL),
 
-  AccURL = CAUrl ++ ?REGURL ++ AccId,
+  AccURL = CAUrl ++ "/acme/reg/" ++ AccId,
   {ok, {_TOS, Account}, Nonce1} = get_account(AccURL, PrivateKey, Nonce0).
 
 new_user_scenario(CAUrl) ->
   PrivateKey = generate_key(),
 
-  DirURL = CAUrl ++ "/" ++ ?DIRURL,
+  DirURL = CAUrl ++ "/directory",
   {ok, Dirs, Nonce0} = directory(DirURL),
 
   #{"new-reg" := NewAccURL} = Dirs,
@@ -203,7 +201,7 @@ new_user_scenario(CAUrl) ->
   {ok, {TOS, Account}, Nonce1} = new_account(NewAccURL, PrivateKey, Req0, Nonce0),
 
   {_, AccId} = proplists:lookup(<<"id">>, Account),
-  AccURL = CAUrl ++ ?REGURL ++ integer_to_list(AccId),
+  AccURL = CAUrl ++ "/acme/reg/" ++ integer_to_list(AccId),
   Req1 = [{ <<"agreement">>, list_to_bitstring(TOS)}],
   {ok, Account1, Nonce2} = update_account(AccURL, PrivateKey, Req1, Nonce1),
 
@@ -213,7 +211,7 @@ generate_key() ->
   jose_jwk:generate_key({ec, secp256r1}).
 
 %% Just a test
-scenario0() ->
-  PrivateKey = jose_jwk:from_file(?DEFAULT_KEY_FILE),
+scenario0(KeyFile) ->
+  PrivateKey = jose_jwk:from_file(KeyFile),
   % scenario("http://localhost:4000", "2", PrivateKey).
   new_user_scenario("http://localhost:4000").