1 files changed, 64 insertions, 0 deletions
diff --git a/src/wikiget/validations.py b/src/wikiget/validations.py
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+++ b/src/wikiget/validations.py
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+# wikiget - CLI tool for downloading files from Wikimedia sites
+# Copyright (C) 2018, 2019, 2020 Cody Logan
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# Wikiget is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Wikiget is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Wikiget. If not, see <https://www.gnu.org/licenses/>.
+
+import hashlib
+import re
+
+from . import BLOCKSIZE
+
+
+def valid_file(search_string):
+    """
+    Determines if the given string contains a valid file name, defined as a
+    string ending with a '.' and at least one character, beginning with 'File:'
+    or 'Image:', the standard file prefixes in MediaWiki.
+    :param search_string: string to validate
+    :returns: a regex Match object if there's a match or None otherwise
+    """
+    # second group could also restrict to file extensions with three or more
+    # letters with ([^/\r\n\t\f\v]+\.\w{3,})
+    file_regex = re.compile(r"(File:|Image:)([^/\r\n\t\f\v]+\.\w+)$", re.I)
+    return file_regex.search(search_string)
+
+
+def valid_site(search_string):
+    """
+    Determines if the given string contains a valid site name, defined as a
+    string ending with 'wikipedia.org' or 'wikimedia.org'. This covers all
+    subdomains of those domains. Eventually, it should be possible to support
+    any MediaWiki site, regardless of domain name.
+    :param search_string: string to validate
+    :returns: a regex Match object if there's a match or None otherwise
+    """
+    site_regex = re.compile(r"wiki[mp]edia\.org$", re.I)
+    return site_regex.search(search_string)
+
+
+def verify_hash(filename):
+    """
+    Calculates the SHA1 hash of the given file for comparison with a known
+    value.
+    :param filename: name of the file to calculate a hash for
+    :return: hash digest
+    """
+    hasher = hashlib.sha1()
+    with open(filename, "rb") as dl:
+        buf = dl.read(BLOCKSIZE)
+        while len(buf) > 0:
+            hasher.update(buf)
+            buf = dl.read(BLOCKSIZE)
+    return hasher.hexdigest()