simplify youtube signature generation

1 files changed, 8 insertions, 7 deletions

diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index b2ecc87e7..8470c40e2 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -135,19 +135,20 @@ class YoutubeIE(InfoExtractor):
             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]
+            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] + 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]
+            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] + 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]
+            return s[2:17] + s[0] + s[18:41] + s[79] + s[42:79] + s[82] + s[80:82] + 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]
+            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] + 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]
+            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[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]
+            return s[52] + s[81:55:-1] + s[2] + s[54:52:-1] + s[82] + s[51:36:-1] + s[55] + s[35:2:-1] + 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]
+            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]
+
         else:
             raise ExtractorError(u'Unable to decrypt signature, subkeys length %d not supported; retrying might work' % (len(s)))