Refactor signature extraction

pull/1004/head
Omar Roth 5 years ago
parent 830692dd60
commit 648cc0f006
No known key found for this signature in database
GPG Key ID: B8254FB7EC3D37F2

@ -207,7 +207,7 @@ spawn do
end
end
decrypt_function = [] of {name: String, value: Int32}
decrypt_function = [] of {SigProc, Int32}
spawn do
update_decrypt_function do |function|
decrypt_function = function

@ -1,69 +1,53 @@
alias SigProc = Proc(Array(String), Int32, Array(String))
def fetch_decrypt_function(id = "CvFH_6DNRCY")
document = YT_POOL.client &.get("/watch?v=#{id}&gl=US&hl=en&disable_polymer=1").body
url = document.match(/src="(?<url>\/yts\/jsbin\/player_ias-.{9}\/en_US\/base.js)"/).not_nil!["url"]
url = document.match(/src="(?<url>\/yts\/jsbin\/player_ias-[^\/]+\/en_US\/base.js)"/).not_nil!["url"]
player = YT_POOL.client &.get(url).body
function_name = player.match(/^(?<name>[^=]+)=function\(a\){a=a\.split\(""\)/m).not_nil!["name"]
function_body = player.match(/^#{Regex.escape(function_name)}=function\(a\){(?<body>[^}]+)}/m).not_nil!["body"]
function_name = player.match(/^(?<name>[^=]+)=function\(\w\){\w=\w\.split\(""\);[^\. ]+\.[^( ]+/m).not_nil!["name"]
function_body = player.match(/^#{Regex.escape(function_name)}=function\(\w\){(?<body>[^}]+)}/m).not_nil!["body"]
function_body = function_body.split(";")[1..-2]
var_name = function_body[0][0, 2]
var_body = player.delete("\n").match(/var #{Regex.escape(var_name)}={(?<body>(.*?))};/).not_nil!["body"]
operations = {} of String => String
operations = {} of String => SigProc
var_body.split("},").each do |operation|
op_name = operation.match(/^[^:]+/).not_nil![0]
op_body = operation.match(/\{[^}]+/).not_nil![0]
case op_body
when "{a.reverse()"
operations[op_name] = "a"
operations[op_name] = ->(a : Array(String), b : Int32) { a.reverse }
when "{a.splice(0,b)"
operations[op_name] = "b"
operations[op_name] = ->(a : Array(String), b : Int32) { a.delete_at(0..(b - 1)); a }
else
operations[op_name] = "c"
operations[op_name] = ->(a : Array(String), b : Int32) { c = a[0]; a[0] = a[b % a.size]; a[b % a.size] = c; a }
end
end
decrypt_function = [] of {name: String, value: Int32}
decrypt_function = [] of {SigProc, Int32}
function_body.each do |function|
function = function.lchop(var_name).delete("[].")
op_name = function.match(/[^\(]+/).not_nil![0]
value = function.match(/\(a,(?<value>[\d]+)\)/).not_nil!["value"].to_i
value = function.match(/\(\w,(?<value>[\d]+)\)/).not_nil!["value"].to_i
decrypt_function << {name: operations[op_name], value: value}
decrypt_function << {operations[op_name], value}
end
return decrypt_function
end
def decrypt_signature(fmt, code)
if !fmt["s"]?
return ""
end
a = fmt["s"]
a = a.split("")
def decrypt_signature(fmt, op)
return "" if !fmt["s"]? || !fmt["sp"]?
code.each do |item|
case item[:name]
when "a"
a.reverse!
when "b"
a.delete_at(0..(item[:value] - 1))
when "c"
a = splice(a, item[:value])
end
sp = fmt["sp"]
sig = fmt["s"].split("")
op.each do |proc, value|
sig = proc.call(sig, value)
end
signature = a.join("")
return "&#{fmt["sp"]?}=#{signature}"
end
def splice(a, b)
c = a[0]
a[0] = a[b % a.size]
a[b % a.size] = c
return a
return "&#{sp}=#{sig.join("")}"
end

Loading…
Cancel
Save