Merge pull request #268 from ewestbrook/prc-multischeme

Scheme-independent connection and redirection

src/http.lua

@@ -26,15 +26,24 @@ _M.TIMEOUT = 60
 -- user agent field sent in request
 _M.USERAGENT = socket._VERSION
 
--- supported schemes
+-- supported schemes and their particulars
 local SCHEMES = {
-    http = { port = 80 }
-    , https = { port = 443 }}
+    http = {
+        port = 80
+        , create = function(t)
+            return socket.tcp end }
+    , https = {
+        port = 443
+        , create = function(t)
+          local https = assert(
+            require("ssl.https"), 'LuaSocket: LuaSec not found')
+          local tcp = assert(
+            https.tcp, 'LuaSocket: Function tcp() not available from LuaSec')
+          return tcp(t) end }}
 
 -- default scheme and port for document retrieval
 local SCHEME = 'http'
 local PORT = SCHEMES[SCHEME].port
-
 -----------------------------------------------------------------------------
 -- Reads MIME headers from a connection, unfolding where needed
 -----------------------------------------------------------------------------
@@ -115,13 +124,13 @@ local metat = { __index = {} }
 
 function _M.open(host, port, create)
     -- create socket with user connect function, or with default
-    local c = socket.try((create or socket.tcp)())
+    local c = socket.try(create())
     local h = base.setmetatable({ c = c }, metat)
     -- create finalized try
     h.try = socket.newtry(function() h:close() end)
     -- set timeout before connecting
     h.try(c:settimeout(_M.TIMEOUT))
-    h.try(c:connect(host, port or PORT))
+    h.try(c:connect(host, port))
     -- here everything worked
     return h
 end
@@ -221,14 +230,13 @@ end
 
 local function adjustheaders(reqt)
     -- default headers
-    local headhost = reqt.host
-    local headport = tostring(reqt.port)
-    local schemeport = tostring(SCHEMES[reqt.scheme].port)
-    if headport ~= schemeport then
-        headhost = headhost .. ':' .. headport end
+    local host = reqt.host
+    local port = tostring(reqt.port)
+    if port ~= tostring(SCHEMES[reqt.scheme].port) then
+        host = host .. ':' .. port end
     local lower = {
         ["user-agent"] = _M.USERAGENT,
-        ["host"] = headhost,
+        ["host"] = host,
         ["connection"] = "close, TE",
         ["te"] = "trailers"
     }
@@ -267,8 +275,13 @@ local function adjustrequest(reqt)
     local nreqt = reqt.url and url.parse(reqt.url, default) or {}
     -- explicit components override url
     for i,v in base.pairs(reqt) do nreqt[i] = v end
-    if nreqt.port == "" then nreqt.port = PORT end
-    if not (nreqt.host and nreqt.host ~= "") then
+    -- default to scheme particulars
+    local schemedefs, host, port, method
+        = SCHEMES[nreqt.scheme], nreqt.host, nreqt.port, nreqt.method
+    if not nreqt.create then nreqt.create = schemedefs.create(nreqt) end
+    if not (port and port ~= '') then nreqt.port = schemedefs.port end
+    if not (method and method ~= '') then nreqt.method = 'GET' end
+    if not (host and host ~= "") then
         socket.try(nil, "invalid host '" .. base.tostring(nreqt.host) .. "'")
     end
     -- compute uri if user hasn't overriden
@@ -285,8 +298,10 @@ local function shouldredirect(reqt, code, headers)
     if not location then return false end
     location = string.gsub(location, "%s", "")
     if location == "" then return false end
-    local scheme = string.match(location, "^([%w][%w%+%-%.]*)%:")
-    if scheme and not SCHEMES[scheme] then return false end
+    local scheme = url.parse(location).scheme
+    if scheme and (not SCHEMES[scheme]) then return false end
+    -- avoid https downgrades
+    if ('https' == reqt.scheme) and ('https' ~= scheme) then return false end
     return (reqt.redirect ~= false) and
            (code == 301 or code == 302 or code == 303 or code == 307) and
            (not reqt.method or reqt.method == "GET" or reqt.method == "HEAD")
@@ -306,10 +321,16 @@ end
 local trequest, tredirect
 
 --[[local]] function tredirect(reqt, location)
-    local result, code, headers, status = trequest {
     -- the RFC says the redirect URL has to be absolute, but some
     -- servers do not respect that
-        url = url.absolute(reqt.url, location),
+    local newurl = url.absolute(reqt.url, location)
+    -- if switching schemes, reset port and create function
+    if url.parse(newurl).scheme ~= reqt.scheme then
+        reqt.port = nil
+        reqt.create = nil end
+    -- make new request
+    local result, code, headers, status = trequest {
+        url = newurl,
         source = reqt.source,
         sink = reqt.sink,
         headers = reqt.headers,
@@ -397,4 +418,5 @@ _M.request = socket.protect(function(reqt, body)
     else return trequest(reqt) end
 end)
 
+_M.schemes = SCHEMES
 return _M