Add a clean-room implementation for youtube signatures

1 files changed, 18 insertions, 8 deletions

diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 6728f5418..b2ecc87e7 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -131,15 +131,25 @@ class YoutubeIE(InfoExtractor):
 
     def _decrypt_signature(self, s):
         """Decrypt the key the two subkeys must have a length of 43"""
-        (a,b) = s.split('.')
-        if len(a) != 43 or len(b) != 43:
-            raise ExtractorError(u'Unable to decrypt signature, subkeys lengths %d.%d not supported; retrying might work' % (len(a), len(b)))
         if self._downloader.params.get('verbose'):
-            self.to_screen('encrypted signature length %d.%d' % (len(a), len(b)))
-        b = ''.join([b[:8],a[0],b[9:18],b[-4],b[19:39], b[18]])[0:40]
-        a = a[-40:]
-        s_dec = '.'.join((a,b))[::-1]
-        return s_dec
+            self.to_screen('encrypted signature length %d' % (len(s)))
+
+        if len(s) == 88:
+            return s[48] + s[81] + s[80] + s[79] + s[78] + s[77] + s[76] + s[75] + s[74] + s[73] + s[72] + s[71] + s[70] + s[69] + s[68] + s[82] + s[66] + s[65] + s[64] + s[63] + s[85] + s[61] + s[60] + s[59] + s[58] + s[57] + s[56] + s[55] + s[54] + s[53] + s[52] + s[51] + s[50] + s[49] + s[67] + s[47] + s[46] + s[45] + s[44] + s[43] + s[42] + s[41] + s[40] + s[39] + s[38] + s[37] + s[36] + s[35] + s[34] + s[33] + s[32] + s[31] + s[30] + s[29] + s[28] + s[27] + s[26] + s[25] + s[24] + s[23] + s[22] + s[21] + s[20] + s[19] + s[18] + s[17] + s[16] + s[15] + s[14] + s[13] + s[3] + s[11] + s[10] + s[9] + s[8] + s[7] + s[6] + s[5] + s[4] + s[2] + s[12]
+        elif len(s) == 87:
+            return s[62] + s[82] + s[81] + s[80] + s[79] + s[78] + s[77] + s[76] + s[75] + s[74] + s[73] + s[72] + s[71] + s[70] + s[69] + s[68] + s[67] + s[66] + s[65] + s[64] + s[63] + s[83] + s[61] + s[60] + s[59] + s[58] + s[57] + s[56] + s[55] + s[54] + s[53] + s[0] + s[51] + s[50] + s[49] + s[48] + s[47] + s[46] + s[45] + s[44] + s[43] + s[42] + s[41] + s[40] + s[39] + s[38] + s[37] + s[36] + s[35] + s[34] + s[33] + s[32] + s[31] + s[30] + s[29] + s[28] + s[27] + s[26] + s[25] + s[24] + s[23] + s[22] + s[21] + s[20] + s[19] + s[18] + s[17] + s[16] + s[15] + s[14] + s[13] + s[12] + s[11] + s[10] + s[9] + s[8] + s[7] + s[6] + s[5] + s[4] + s[3]
+        elif len(s) == 86:
+            return s[2] + s[3] + s[4] + s[5] + s[6] + s[7] + s[8] + s[9] + s[10] + s[11] + s[12] + s[13] + s[14] + s[15] + s[16] + s[0] + s[18] + s[19] + s[20] + s[21] + s[22] + s[23] + s[24] + s[25] + s[26] + s[27] + s[28] + s[29] + s[30] + s[31] + s[32] + s[33] + s[34] + s[35] + s[36] + s[37] + s[38] + s[39] + s[40] + s[79] + s[42] + s[43] + s[44] + s[45] + s[46] + s[47] + s[48] + s[49] + s[50] + s[51] + s[52] + s[53] + s[54] + s[55] + s[56] + s[57] + s[58] + s[59] + s[60] + s[61] + s[62] + s[63] + s[64] + s[65] + s[66] + s[67] + s[68] + s[69] + s[70] + s[71] + s[72] + s[73] + s[74] + s[75] + s[76] + s[77] + s[78] + s[82] + s[80] + s[81] + s[41]
+        elif len(s) == 85:
+            return s[76] + s[82] + s[81] + s[80] + s[79] + s[78] + s[77] + s[83] + s[75] + s[74] + s[73] + s[72] + s[71] + s[70] + s[69] + s[68] + s[67] + s[66] + s[65] + s[64] + s[63] + s[62] + s[61] + s[0] + s[59] + s[58] + s[57] + s[56] + s[55] + s[54] + s[53] + s[52] + s[51] + s[1] + s[49] + s[48] + s[47] + s[46] + s[45] + s[44] + s[43] + s[42] + s[41] + s[40] + s[39] + s[38] + s[37] + s[36] + s[35] + s[34] + s[33] + s[32] + s[31] + s[30] + s[29] + s[28] + s[27] + s[26] + s[25] + s[24] + s[23] + s[22] + s[21] + s[20] + s[19] + s[18] + s[17] + s[16] + s[15] + s[14] + s[13] + s[12] + s[11] + s[10] + s[9] + s[8] + s[7] + s[6] + s[5] + s[4] + s[3]
+        elif len(s) == 84:
+            return s[83] + s[82] + s[81] + s[80] + s[79] + s[78] + s[77] + s[76] + s[75] + s[74] + s[73] + s[72] + s[71] + s[70] + s[69] + s[68] + s[67] + s[66] + s[65] + s[64] + s[63] + s[62] + s[61] + s[60] + s[59] + s[58] + s[57] + s[56] + s[55] + s[54] + s[53] + s[52] + s[51] + s[50] + s[49] + s[48] + s[47] + s[46] + s[45] + s[44] + s[43] + s[42] + s[41] + s[40] + s[39] + s[38] + s[37] + s[2] + s[35] + s[34] + s[33] + s[32] + s[31] + s[30] + s[29] + s[28] + s[27] + s[3] + s[25] + s[24] + s[23] + s[22] + s[21] + s[20] + s[19] + s[18] + s[17] + s[16] + s[15] + s[14] + s[13] + s[12] + s[11] + s[10] + s[9] + s[8] + s[7] + s[6] + s[5] + s[4] + s[26]
+        elif len(s) == 83:
+            return s[52] + s[81] + s[80] + s[79] + s[78] + s[77] + s[76] + s[75] + s[74] + s[73] + s[72] + s[71] + s[70] + s[69] + s[68] + s[67] + s[66] + s[65] + s[64] + s[63] + s[62] + s[61] + s[60] + s[59] + s[58] + s[57] + s[56] + s[2] + s[54] + s[53] + s[82] + s[51] + s[50] + s[49] + s[48] + s[47] + s[46] + s[45] + s[44] + s[43] + s[42] + s[41] + s[40] + s[39] + s[38] + s[37] + s[55] + s[35] + s[34] + s[33] + s[32] + s[31] + s[30] + s[29] + s[28] + s[27] + s[26] + s[25] + s[24] + s[23] + s[22] + s[21] + s[20] + s[19] + s[18] + s[17] + s[16] + s[15] + s[14] + s[13] + s[12] + s[11] + s[10] + s[9] + s[8] + s[7] + s[6] + s[5] + s[4] + s[3] + s[36]
+        elif len(s) == 82:
+            return s[36] + s[79] + s[78] + s[77] + s[76] + s[75] + s[74] + s[73] + s[72] + s[71] + s[70] + s[69] + s[68] + s[81] + s[66] + s[65] + s[64] + s[63] + s[62] + s[61] + s[60] + s[59] + s[58] + s[57] + s[56] + s[55] + s[54] + s[53] + s[52] + s[51] + s[50] + s[49] + s[48] + s[47] + s[46] + s[45] + s[44] + s[43] + s[42] + s[41] + s[33] + s[39] + s[38] + s[37] + s[40] + s[35] + s[0] + s[67] + s[32] + s[31] + s[30] + s[29] + s[28] + s[27] + s[26] + s[25] + s[24] + s[23] + s[22] + s[21] + s[20] + s[19] + s[18] + s[17] + s[16] + s[15] + s[14] + s[13] + s[12] + s[11] + s[10] + s[9] + s[8] + s[7] + s[6] + s[5] + s[4] + s[3] + s[2] + s[1] + s[34]
+        else:
+            raise ExtractorError(u'Unable to decrypt signature, subkeys length %d not supported; retrying might work' % (len(s)))
 
     def _get_available_subtitles(self, video_id):
         self.report_video_subtitles_download(video_id)