Shared: Provide custom isURI that rejects unknown schemes [isURI]

We also export the set of known `schemes`.

The new function replaces the function of the same name
from `Network.URI`, as the latter did not check whether a scheme is
well-known.  E.g. MediaWiki wikis frequently feature pages with names
like `User:John`. These links were interpreted as URIs, thus turning
internal links into global links. This is prevented by also checking
whether the scheme of a URI is frequently used (i.e. is IANA registered
or an otherwise well-known scheme).

Fixes: #2713

Update set of well-known URIs from IANA list
All official IANA schemes (as of 2017-05-22) are included in the set of
known schemes.  The four non-official schemes doi, isbn, javascript, and
pmid are kept.

16 files changed, 81 insertions, 48 deletions

diff --git a/src/Text/Pandoc/App.hs b/src/Text/Pandoc/App.hs
index 97954764a..845146f34 100644
--- a/src/Text/Pandoc/App.hs
+++ b/src/Text/Pandoc/App.hs
@@ -57,7 +57,7 @@ import Data.Maybe (fromMaybe, isJust, isNothing)
 import qualified Data.Text as T
 import Data.Yaml (decode)
 import qualified Data.Yaml as Yaml
-import Network.URI (URI (..), isURI, parseURI)
+import Network.URI (URI (..), parseURI)
 import Paths_pandoc (getDataDir)
 import Skylighting (Style, Syntax (..), defaultSyntaxMap, parseTheme)
 import Skylighting.Parser (missingIncludes, parseSyntaxDefinition,
@@ -80,7 +80,7 @@ import Text.Pandoc.Lua ( runLuaFilter )
 import Text.Pandoc.PDF (makePDF)
 import Text.Pandoc.Process (pipeProcess)
 import Text.Pandoc.SelfContained (makeSelfContained, makeDataURI)
-import Text.Pandoc.Shared (headerShift, openURL, readDataFile,
+import Text.Pandoc.Shared (isURI, headerShift, openURL, readDataFile,
                            readDataFileUTF8, safeRead, tabFilter)
 import qualified Text.Pandoc.UTF8 as UTF8
 import Text.Pandoc.XML (toEntities)
diff --git a/src/Text/Pandoc/Parsing.hs b/src/Text/Pandoc/Parsing.hs
index e430c7cb5..c6be48d19 100644
--- a/src/Text/Pandoc/Parsing.hs
+++ b/src/Text/Pandoc/Parsing.hs
@@ -465,33 +465,8 @@ emailAddress = try $ toResult <$> mailbox <*> (char '@' *> domain)
        sepby1 p sep      = (:) <$> p <*> (many (try $ sep >> p))
 
 
--- Schemes from http://www.iana.org/assignments/uri-schemes.html plus
--- the unofficial schemes coap, doi, javascript, isbn, pmid
-schemes :: [String]
-schemes = ["coap","doi","javascript","aaa","aaas","about","acap","cap","cid",
-           "crid","data","dav","dict","dns","file","ftp","geo","go","gopher",
-           "h323","http","https","iax","icap","im","imap","info","ipp","iris",
-           "iris.beep","iris.xpc","iris.xpcs","iris.lwz","ldap","mailto","mid",
-           "msrp","msrps","mtqp","mupdate","news","nfs","ni","nih","nntp",
-           "opaquelocktoken","pop","pres","rtsp","service","session","shttp","sieve",
-           "sip","sips","sms","snmp","soap.beep","soap.beeps","tag","tel","telnet",
-           "tftp","thismessage","tn3270","tip","tv","urn","vemmi","ws","wss","xcon",
-           "xcon-userid","xmlrpc.beep","xmlrpc.beeps","xmpp","z39.50r","z39.50s",
-           "adiumxtra","afp","afs","aim","apt","attachment","aw","beshare","bitcoin",
-           "bolo","callto","chrome","chrome-extension","com-eventbrite-attendee",
-           "content", "cvs","dlna-playsingle","dlna-playcontainer","dtn","dvb",
-           "ed2k","facetime","feed","finger","fish","gg","git","gizmoproject",
-           "gtalk","hcp","icon","ipn","irc","irc6","ircs","itms","jar","jms",
-           "keyparc","lastfm","ldaps","magnet","maps","market","message","mms",
-           "ms-help","msnim","mumble","mvn","notes","oid","palm","paparazzi",
-           "platform","proxy","psyc","query","res","resource","rmi","rsync",
-           "rtmp","secondlife","sftp","sgn","skype","smb","soldat","spotify",
-           "ssh","steam","svn","teamspeak","things","udp","unreal","ut2004",
-           "ventrilo","view-source","webcal","wtai","wyciwyg","xfire","xri",
-           "ymsgr", "isbn", "pmid"]
-
 uriScheme :: Stream s m Char => ParserT s st m String
-uriScheme = oneOfStringsCI schemes
+uriScheme = oneOfStringsCI (Set.toList schemes)
 
 -- | Parses a URI. Returns pair of original and URI-escaped version.
 uri :: Stream [Char] m Char => ParserT [Char] st m (String, String)
diff --git a/src/Text/Pandoc/Readers/Txt2Tags.hs b/src/Text/Pandoc/Readers/Txt2Tags.hs
index ba2b20083..05c6c9a69 100644
--- a/src/Text/Pandoc/Readers/Txt2Tags.hs
+++ b/src/Text/Pandoc/Readers/Txt2Tags.hs
@@ -42,7 +42,6 @@ import Text.Pandoc.Definition
 import Text.Pandoc.Options
 import Text.Pandoc.Parsing hiding (macro, space, spaces, uri)
 import Text.Pandoc.Shared (compactify, compactifyDL, escapeURI)
---import Network.URI (isURI) -- Not sure whether to use this function
 import Control.Monad (guard, void, when)
 import Control.Monad.Reader (Reader, asks, runReader)
 import Data.Default
diff --git a/src/Text/Pandoc/SelfContained.hs b/src/Text/Pandoc/SelfContained.hs
index f8ad43b1e..55df147b6 100644
--- a/src/Text/Pandoc/SelfContained.hs
+++ b/src/Text/Pandoc/SelfContained.hs
@@ -42,7 +42,7 @@ import qualified Data.ByteString.Char8 as B
 import qualified Data.ByteString.Lazy as L
 import Data.Char (isAlphaNum, isAscii, toLower)
 import Data.List (isPrefixOf)
-import Network.URI (URI (..), escapeURIString, isURI, parseURI)
+import Network.URI (URI (..), escapeURIString, parseURI)
 import System.FilePath (takeDirectory, takeExtension, (</>))
 import Text.HTML.TagSoup
 import Text.Pandoc.Class (PandocMonad (..), fetchItem, report)
@@ -50,7 +50,7 @@ import Text.Pandoc.Error
 import Text.Pandoc.Logging
 import Text.Pandoc.MIME (MimeType)
 import Text.Pandoc.Options (WriterOptions (..))
-import Text.Pandoc.Shared (renderTags', trim)
+import Text.Pandoc.Shared (isURI, renderTags', trim)
 import Text.Pandoc.UTF8 (toString)
 import Text.Parsec (ParsecT, runParserT)
 import qualified Text.Parsec as P
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 3a61656e5..7a1e6f3e3 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -81,6 +81,9 @@ module Text.Pandoc.Shared (
                      openURL,
                      collapseFilePath,
                      filteredFilesFromArchive,
+                     -- * URI handling
+                     schemes,
+                     isURI,
                      -- * Error handling
                      mapLeft,
                      -- * for squashing blocks
@@ -104,7 +107,7 @@ import Data.List ( find, stripPrefix, intercalate )
 import Data.Maybe (mapMaybe)
 import Data.Version ( showVersion )
 import qualified Data.Map as M
-import Network.URI ( escapeURIString, unEscapeString )
+import Network.URI ( URI(uriScheme), escapeURIString, unEscapeString, parseURI )
 import qualified Data.Set as Set
 import System.Directory
 import System.FilePath (splitDirectories, isPathSeparator)
@@ -774,6 +777,70 @@ filteredFilesFromArchive zf f =
     fileAndBinary :: Archive -> FilePath -> Maybe (FilePath, BL.ByteString)
     fileAndBinary a fp = findEntryByPath fp a >>= \e -> Just (fp, fromEntry e)
 
+
+--
+-- IANA URIs
+--
+
+-- | Schemes from http://www.iana.org/assignments/uri-schemes.html plus
+-- the unofficial schemes doi, javascript, isbn, pmid.
+schemes :: Set.Set String
+schemes = Set.fromList
+  -- Official IANA schemes
+  [ "aaa", "aaas", "about", "acap", "acct", "acr", "adiumxtra", "afp", "afs"
+  , "aim", "appdata", "apt", "attachment", "aw", "barion", "beshare", "bitcoin"
+  , "blob", "bolo", "browserext", "callto", "cap", "chrome", "chrome-extension"
+  , "cid", "coap", "coaps", "com-eventbrite-attendee", "content", "crid", "cvs"
+  , "data", "dav", "dict", "dis", "dlna-playcontainer", "dlna-playsingle"
+  , "dns", "dntp", "dtn", "dvb", "ed2k", "example", "facetime", "fax", "feed"
+  , "feedready", "file", "filesystem", "finger", "fish", "ftp", "geo", "gg"
+  , "git", "gizmoproject", "go", "gopher", "graph", "gtalk", "h323", "ham"
+  , "hcp", "http", "https", "hxxp", "hxxps", "hydrazone", "iax", "icap", "icon"
+  , "im", "imap", "info", "iotdisco", "ipn", "ipp", "ipps", "irc", "irc6"
+  , "ircs", "iris", "iris.beep", "iris.lwz", "iris.xpc", "iris.xpcs"
+  , "isostore", "itms", "jabber", "jar", "jms", "keyparc", "lastfm", "ldap"
+  , "ldaps", "lvlt", "magnet", "mailserver", "mailto", "maps", "market"
+  , "message", "mid", "mms", "modem", "mongodb", "moz", "ms-access"
+  , "ms-browser-extension", "ms-drive-to", "ms-enrollment", "ms-excel"
+  , "ms-gamebarservices", "ms-getoffice", "ms-help", "ms-infopath"
+  , "ms-media-stream-id", "ms-officeapp", "ms-project", "ms-powerpoint"
+  , "ms-publisher", "ms-search-repair", "ms-secondary-screen-controller"
+  , "ms-secondary-screen-setup", "ms-settings", "ms-settings-airplanemode"
+  , "ms-settings-bluetooth", "ms-settings-camera", "ms-settings-cellular"
+  , "ms-settings-cloudstorage", "ms-settings-connectabledevices"
+  , "ms-settings-displays-topology", "ms-settings-emailandaccounts"
+  , "ms-settings-language", "ms-settings-location", "ms-settings-lock"
+  , "ms-settings-nfctransactions", "ms-settings-notifications"
+  , "ms-settings-power", "ms-settings-privacy", "ms-settings-proximity"
+  , "ms-settings-screenrotation", "ms-settings-wifi", "ms-settings-workplace"
+  , "ms-spd", "ms-sttoverlay", "ms-transit-to", "ms-virtualtouchpad"
+  , "ms-visio", "ms-walk-to", "ms-whiteboard", "ms-whiteboard-cmd", "ms-word"
+  , "msnim", "msrp", "msrps", "mtqp", "mumble", "mupdate", "mvn", "news", "nfs"
+  , "ni", "nih", "nntp", "notes", "ocf", "oid", "onenote", "onenote-cmd"
+  , "opaquelocktoken", "pack", "palm", "paparazzi", "pkcs11", "platform", "pop"
+  , "pres", "prospero", "proxy", "pwid", "psyc", "qb", "query", "redis"
+  , "rediss", "reload", "res", "resource", "rmi", "rsync", "rtmfp", "rtmp"
+  , "rtsp", "rtsps", "rtspu", "secondlife", "service", "session", "sftp", "sgn"
+  , "shttp", "sieve", "sip", "sips", "skype", "smb", "sms", "smtp", "snews"
+  , "snmp", "soap.beep", "soap.beeps", "soldat", "spotify", "ssh", "steam"
+  , "stun", "stuns", "submit", "svn", "tag", "teamspeak", "tel", "teliaeid"
+  , "telnet", "tftp", "things", "thismessage", "tip", "tn3270", "tool", "turn"
+  , "turns", "tv", "udp", "unreal", "urn", "ut2004", "v-event", "vemmi"
+  , "ventrilo", "videotex", "vnc", "view-source", "wais", "webcal", "wpid"
+  , "ws", "wss", "wtai", "wyciwyg", "xcon", "xcon-userid", "xfire"
+  , "xmlrpc.beep", "xmlrpc.beeps", "xmpp", "xri", "ymsgr", "z39.50", "z39.50r"
+  , "z39.50s"
+  -- Inofficial schemes
+  , "doi", "isbn", "javascript", "pmid"
+  ]
+
+-- | Check if the string is a valid URL with a IANA or frequently used but
+-- unofficial scheme (see @schemes@).
+isURI :: String -> Bool
+isURI = maybe False hasKnownScheme . parseURI
+  where
+    hasKnownScheme = (`Set.member` schemes) . filter (/= ':') . uriScheme
+
 ---
 --- Squash blocks into inlines
 ---
diff --git a/src/Text/Pandoc/Writers/ConTeXt.hs b/src/Text/Pandoc/Writers/ConTeXt.hs
index eef16d3da..2d4502153 100644
--- a/src/Text/Pandoc/Writers/ConTeXt.hs
+++ b/src/Text/Pandoc/Writers/ConTeXt.hs
@@ -33,7 +33,7 @@ import Control.Monad.State
 import Data.Char (ord)
 import Data.List (intercalate, intersperse)
 import Data.Maybe (catMaybes)
-import Network.URI (isURI, unEscapeString)
+import Network.URI (unEscapeString)
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Logging
 import Text.Pandoc.Definition
diff --git a/src/Text/Pandoc/Writers/DokuWiki.hs b/src/Text/Pandoc/Writers/DokuWiki.hs
index 81987dc44..1d02a9c40 100644
--- a/src/Text/Pandoc/Writers/DokuWiki.hs
+++ b/src/Text/Pandoc/Writers/DokuWiki.hs
@@ -44,13 +44,12 @@ import Control.Monad.Reader (ReaderT, ask, local, runReaderT)
 import Control.Monad.State (StateT, evalStateT, gets, modify)
 import Data.Default (Default (..))
 import Data.List (intercalate, intersect, isPrefixOf, transpose)
-import Network.URI (isURI)
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Logging
 import Text.Pandoc.Definition
 import Text.Pandoc.ImageSize
 import Text.Pandoc.Options (WrapOption (..), WriterOptions (writerTableOfContents, writerTemplate, writerWrapText))
-import Text.Pandoc.Shared (camelCaseToHyphenated, escapeURI, linesToPara,
+import Text.Pandoc.Shared (camelCaseToHyphenated, escapeURI, isURI, linesToPara,
                            removeFormatting, substitute, trimr)
 import Text.Pandoc.Templates (renderTemplate')
 import Text.Pandoc.Writers.Shared (defField, metaToJSON)
diff --git a/src/Text/Pandoc/Writers/FB2.hs b/src/Text/Pandoc/Writers/FB2.hs
index 0926cc331..d450513bc 100644
--- a/src/Text/Pandoc/Writers/FB2.hs
+++ b/src/Text/Pandoc/Writers/FB2.hs
@@ -46,7 +46,6 @@ import Data.Char (isAscii, isControl, isSpace, toLower)
 import Data.Either (lefts, rights)
 import Data.List (intercalate, intersperse, isPrefixOf, stripPrefix)
 import Network.HTTP (urlEncode)
-import Network.URI (isURI)
 import Text.XML.Light
 import qualified Text.XML.Light as X
 import qualified Text.XML.Light.Cursor as XC
@@ -57,7 +56,7 @@ import Text.Pandoc.Definition
 import Text.Pandoc.Error
 import Text.Pandoc.Logging
 import Text.Pandoc.Options (HTMLMathMethod (..), WriterOptions (..), def)
-import Text.Pandoc.Shared (capitalize, isHeaderBlock, linesToPara,
+import Text.Pandoc.Shared (capitalize, isHeaderBlock, isURI, linesToPara,
                            orderedListMarkers)
 
 -- | Data to be written at the end of the document:
diff --git a/src/Text/Pandoc/Writers/Haddock.hs b/src/Text/Pandoc/Writers/Haddock.hs
index 812b46c30..cbbe5bdb4 100644
--- a/src/Text/Pandoc/Writers/Haddock.hs
+++ b/src/Text/Pandoc/Writers/Haddock.hs
@@ -36,7 +36,6 @@ module Text.Pandoc.Writers.Haddock (writeHaddock) where
 import Control.Monad.State
 import Data.Default
 import Data.List (intersperse, transpose)
-import Network.URI (isURI)
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Definition
 import Text.Pandoc.Logging
diff --git a/src/Text/Pandoc/Writers/ICML.hs b/src/Text/Pandoc/Writers/ICML.hs
index 2f7a4889f..f36a32015 100644
--- a/src/Text/Pandoc/Writers/ICML.hs
+++ b/src/Text/Pandoc/Writers/ICML.hs
@@ -21,7 +21,6 @@ import Control.Monad.State
 import Data.List (intersperse, isInfixOf, isPrefixOf, stripPrefix)
 import qualified Data.Set as Set
 import Data.Text as Text (breakOnAll, pack)
-import Network.URI (isURI)
 import Text.Pandoc.Class (PandocMonad, report)
 import qualified Text.Pandoc.Class as P
 import Text.Pandoc.Definition
@@ -29,7 +28,7 @@ import Text.Pandoc.ImageSize
 import Text.Pandoc.Logging
 import Text.Pandoc.Options
 import Text.Pandoc.Pretty
-import Text.Pandoc.Shared (linesToPara, splitBy)
+import Text.Pandoc.Shared (isURI, linesToPara, splitBy)
 import Text.Pandoc.Templates (renderTemplate')
 import Text.Pandoc.Writers.Math (texMathToInlines)
 import Text.Pandoc.Writers.Shared
diff --git a/src/Text/Pandoc/Writers/LaTeX.hs b/src/Text/Pandoc/Writers/LaTeX.hs
index 31c70e99d..2b3d7c878 100644
--- a/src/Text/Pandoc/Writers/LaTeX.hs
+++ b/src/Text/Pandoc/Writers/LaTeX.hs
@@ -43,7 +43,7 @@ import Data.List (foldl', intercalate, intersperse, isInfixOf, nub, nubBy,
                   stripPrefix, (\\))
 import Data.Maybe (catMaybes, fromMaybe, isJust)
 import qualified Data.Text as T
-import Network.URI (isURI, unEscapeString)
+import Network.URI (unEscapeString)
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Definition
 import Text.Pandoc.Highlighting (formatLaTeXBlock, formatLaTeXInline, highlight,
diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index b70716181..e858bc43f 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -49,7 +49,6 @@ import qualified Data.Text as T
 import qualified Data.Vector as V
 import Data.Yaml (Value (Array, Bool, Number, Object, String))
 import Network.HTTP (urlEncode)
-import Network.URI (isURI)
 import Text.HTML.TagSoup (Tag (..), isTagText, parseTags)
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Definition
diff --git a/src/Text/Pandoc/Writers/MediaWiki.hs b/src/Text/Pandoc/Writers/MediaWiki.hs
index 439bbb2f9..aa5c3bc4f 100644
--- a/src/Text/Pandoc/Writers/MediaWiki.hs
+++ b/src/Text/Pandoc/Writers/MediaWiki.hs
@@ -34,7 +34,6 @@ import Control.Monad.Reader
 import Control.Monad.State
 import Data.List (intercalate)
 import qualified Data.Set as Set
-import Network.URI (isURI)
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Logging
 import Text.Pandoc.Definition
diff --git a/src/Text/Pandoc/Writers/RST.hs b/src/Text/Pandoc/Writers/RST.hs
index 5dc2ba31a..b88fc2245 100644
--- a/src/Text/Pandoc/Writers/RST.hs
+++ b/src/Text/Pandoc/Writers/RST.hs
@@ -35,7 +35,6 @@ import Control.Monad.State
 import Data.Char (isSpace, toLower)
 import Data.List (isPrefixOf, stripPrefix)
 import Data.Maybe (fromMaybe)
-import Network.URI (isURI)
 import qualified Text.Pandoc.Builder as B
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Logging
diff --git a/src/Text/Pandoc/Writers/Texinfo.hs b/src/Text/Pandoc/Writers/Texinfo.hs
index 9926daea1..710e1dea0 100644
--- a/src/Text/Pandoc/Writers/Texinfo.hs
+++ b/src/Text/Pandoc/Writers/Texinfo.hs
@@ -37,7 +37,7 @@ import Data.Char (chr, ord)
 import Data.List (maximumBy, transpose)
 import Data.Ord (comparing)
 import qualified Data.Set as Set
-import Network.URI (isURI, unEscapeString)
+import Network.URI (unEscapeString)
 import System.FilePath
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Definition
diff --git a/src/Text/Pandoc/Writers/ZimWiki.hs b/src/Text/Pandoc/Writers/ZimWiki.hs
index bc2cf8f3c..4ab8bde30 100644
--- a/src/Text/Pandoc/Writers/ZimWiki.hs
+++ b/src/Text/Pandoc/Writers/ZimWiki.hs
@@ -38,14 +38,13 @@ import Data.Default (Default (..))
 import Data.List (intercalate, isInfixOf, isPrefixOf, transpose)
 import qualified Data.Map as Map
 import Data.Text (breakOnAll, pack)
-import Network.URI (isURI)
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.Logging
 import Text.Pandoc.Definition
 import Text.Pandoc.ImageSize
 import Text.Pandoc.Options (WrapOption (..), WriterOptions (writerTableOfContents, writerTemplate, writerWrapText))
-import Text.Pandoc.Shared (escapeURI, linesToPara, removeFormatting, substitute,
-                           trimr)
+import Text.Pandoc.Shared (isURI, escapeURI, linesToPara, removeFormatting,
+                           substitute, trimr)
 import Text.Pandoc.Templates (renderTemplate')
 import Text.Pandoc.Writers.Shared (defField, metaToJSON)