fetcher: Check integrity of files before saving to disk.

Fetcher will check integrity of files using sha1sum file 
(and later with digital signatures) before saving them to 
their original locations.

pisi/constants.py

@@ -57,6 +57,7 @@ class Constants:
         self.__c.xz_suffix = ".xz"
 
         self.__c.partial_suffix = ".part"
+        self.__c.temporary_suffix = ".tmp"
 
         # suffix for auto generated debug packages
         self.__c.debug_name_suffix = "-dbginfo"

pisi/fetcher.py

@@ -105,19 +105,21 @@ class UIHandler:
 class Fetcher:
     """Fetcher can fetch a file from various sources using various
     protocols."""
-    def __init__(self, url, destdir):
+    def __init__(self, url, destdir, destfile=None):
         if not isinstance(url, pisi.uri.URI):
             url = pisi.uri.URI(url)
 
         if ctx.config.get_option("authinfo"):
             url.set_auth_info(ctx.config.get_option("authinfo"))
 
-        self.url      = url
-        self.destdir  = destdir
-        self.archive_file = os.path.join(self.destdir, self.url.filename())
-        self.partial_file = self.archive_file + ctx.const.partial_suffix
+        self.url = url
+        self.destdir = destdir
+        self.destfile = destfile
         self.progress = None
 
+        self.archive_file = os.path.join(destdir, destfile or url.filename())
+        self.partial_file = os.path.join(self.destdir, self.url.filename()) + ctx.const.partial_suffix
+
         util.ensure_dirs(self.destdir)
 
     def fetch (self):
@@ -222,7 +224,7 @@ class Fetcher:
 
 
 # helper function
-def fetch_url(url, destdir, progress=None):
-    fetch = Fetcher(url, destdir)
+def fetch_url(url, destdir, progress=None, destfile=None):
+    fetch = Fetcher(url, destdir, destfile)
     fetch.progress = progress
     fetch.fetch()

pisi/file.py

@@ -108,13 +108,17 @@ class File:
 
         pisi.util.ensure_dirs(transfer_dir)
 
+        # Check file integrity before saving?
+        check_integrity = sha1sum or sign
+
         if sha1sum:
             sha1filename = File.download(pisi.uri.URI(uri.get_uri() + '.sha1sum'), transfer_dir)
             sha1f = file(sha1filename)
             newsha1 = sha1f.read().split("\n")[0]
 
         if uri.is_remote_file() or copylocal:
-            localfile = pisi.util.join_path(transfer_dir, uri.filename())
+            tmpfile = check_integrity and uri.filename() + ctx.const.temporary_suffix
+            localfile = pisi.util.join_path(transfer_dir, tmpfile or uri.filename())
 
             # TODO: code to use old .sha1sum file, is this a necessary optimization?
             #oldsha1fn = localfile + '.sha1sum'
@@ -128,10 +132,9 @@ class File:
 
             if uri.is_remote_file():
                 ctx.ui.info(_("Fetching %s") % uri.get_uri(), verbose=True)
-                pisi.fetcher.fetch_url(uri, transfer_dir, ctx.ui.Progress)
+                pisi.fetcher.fetch_url(uri, transfer_dir, ctx.ui.Progress, tmpfile)
             else:
-                # copy to transfer dir,
-                localfile = pisi.util.join_path(transfer_dir, uri.filename())
+                # copy to transfer dir
                 ctx.ui.info(_("Copying %s to transfer dir") % uri.get_uri(), verbose=True)
                 shutil.copy(uri.get_uri(), transfer_dir)
         else:
@@ -143,10 +146,25 @@ class File:
                 localfile = pisi.util.join_path(transfer_dir, os.path.basename(localfile))
                 shutil.copy(oldfn, localfile)
 
+        def clean_temporary():
+            temp_files = [sha1filename]
+            if check_integrity:
+                temp_files.append(localfile)
+            for filename in temp_files:
+                try:
+                    os.unlink(filename)
+                except OSError:
+                    pass
+
         if sha1sum:
             if (pisi.util.sha1_file(localfile) != newsha1):
+                clean_temporary()
                 raise Error(_("File integrity of %s compromised.") % uri)
 
+        if check_integrity:
+            shutil.move(localfile, origfile)
+            localfile = origfile
+
         localfile = File.decompress(localfile, compress)
 
         return localfile

pisi/package.py

@@ -23,6 +23,7 @@ import pisi.context as ctx
 import pisi.archive as archive
 import pisi.uri
 import pisi.metadata
+import pisi.file
 import pisi.files
 import pisi.util as util
 import fetcher
@@ -95,7 +96,7 @@ class Package:
 
         if not os.path.exists(self.filepath):
             try:
-                fetcher.fetch_url(url, dest, ctx.ui.Progress)
+                pisi.file.File.download(url, dest)
             except pisi.fetcher.FetchError:
                 # Bug 3465
                 if ctx.get_option('reinstall'):