From fe6fad124207979c7d656ceef1ab95c29dc14ac6 Mon Sep 17 00:00:00 2001 From: Anton Novosyolov Date: Wed, 17 Jul 2013 10:41:43 +0400 Subject: [PATCH] [youtube] improved decrypt_signature, closes #1060 --- youtube_dl/extractor/youtube.py | 37 ++++++++++++++++----------------- 1 file changed, 18 insertions(+), 19 deletions(-) diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py index 91cd2192f..b1e2edf75 100644 --- a/youtube_dl/extractor/youtube.py +++ b/youtube_dl/extractor/youtube.py @@ -179,25 +179,24 @@ class YoutubeIE(InfoExtractor): def _decrypt_signature(self, s): """Turn the encrypted s field into a working signature""" - if len(s) == 88: - return s[48] + s[81:67:-1] + s[82] + s[66:62:-1] + s[85] + s[61:48:-1] + s[67] + s[47:12:-1] + s[3] + s[11:3:-1] + s[2] + s[12] - elif len(s) == 87: - return s[62] + s[82:62:-1] + s[83] + s[61:52:-1] + s[0] + s[51:2:-1] - elif len(s) == 86: - return s[2:63] + s[82] + s[64:82] + s[63] - elif len(s) == 85: - return s[76] + s[82:76:-1] + s[83] + s[75:60:-1] + s[0] + s[59:50:-1] + s[1] + s[49:2:-1] - elif len(s) == 84: - return s[83:36:-1] + s[2] + s[35:26:-1] + s[3] + s[25:3:-1] + s[26] - elif len(s) == 83: - return s[6] + s[3:6] + s[33] + s[7:24] + s[0] + s[25:33] + s[53] + s[34:53] + s[24] + s[54:] - elif len(s) == 82: - return s[36] + s[79:67:-1] + s[81] + s[66:40:-1] + s[33] + s[39:36:-1] + s[40] + s[35] + s[0] + s[67] + s[32:0:-1] + s[34] - elif len(s) == 81: - return s[6] + s[3:6] + s[33] + s[7:24] + s[0] + s[25:33] + s[2] + s[34:53] + s[24] + s[54:81] - - else: - raise ExtractorError(u'Unable to decrypt signature, key length %d not supported; retrying might work' % (len(s))) + def voodoo(a, b): + c = a[0]; + a[0] = a[b % len(a)]; + a[b] = c; + return a; + + s = list(s) + s = s[2:len(s)]; + s = s[::-1]; + s = s[3:len(s)]; + s = voodoo(s, 9); + s = s[3:len(s)]; + s = voodoo(s, 43); + s = s[3:len(s)]; + s = s[::-1]; + s = voodoo(s, 23); + s = "".join(s); + return s; def _get_available_subtitles(self, video_id): self.report_video_subtitles_download(video_id)