Nagra Hex Block Decryption Research

schwarzekatze

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Hi guys, anybody already know how dCWPK is generated (on receiver or card)?

There is a lot of false or just useless information that goes nowhere, but anyway this is what I discovery and tested for now about CAK6.3 and CWPK.

Need send NUID to CMD2A to can receive CW (crypted by 3DES), without this no CW is received in some or all HD channels.
This is a example of CMD2A:
A0 CA 00 00 1E 2A 1C 00 FF FF FF FF 00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 22 11 42

A0 CA 00 00 => Header
1E => All Size without Header
2A => Command
1C = > Data Size
00 => ?? (not know)
FF FF FF FF => NUID
00 08 => OTP-CSC (maybe?)
00 00 => OTA-CSC (maybe?)
00 00 00 00 00 00 00 00 => ?? (not know)
00 00 00 00 00 00 00 00 => ?? (not know)
00 => ?? (not know)
22 11 => Provider ID
42 => Expected Response Size


After a lot of tests I discovery:
CWPK only change if NUID is changed.
OTP-CSC or OTA-CSC
needs to be filled to enable CWPK, if both are 00 not will enable CWPK.
Change Provider ID or fill ?? data with random values not make any differ in CWPK.

All tests were performed on a DNASP142 RevG13
i didnt dig deep how it exactly works but basically from my opinion is just otp key matter

from my opinion provider A have root key AABBFF and its smartcards have same key

now when provider A smartcard receive nuid BBAACCFF it calculate SCK key from BBAACCFF+AABBFF = ECW encrypt dcw with sck calculated from obffuscated BBAACCFF+AABBFF value

in stb side cpu calculate same sck key from BBAACCFF+AABBFF it just does ecw decrypt , whether smartcard does dcw encrypt

now provider B doing exactly same with one exception - with the different otp key:

root key CCBBAA:

FFDDAACC+CCBBAA = ECW encrypt dcw smartcard side and dcw decrypt stb cpu side

it so called global dcw pairing closed to 1 provider
it is tied to 1 provider because obffuscated sck values have been calculated from unique otp key so even if you send provider A nuid to provider B smartcard it would calculate you wrong ecw because otp_key calculated sck would not match
 

Benfica200

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ooops seems there will be new 4k nagra provider in poland with latest rom450 smartcard and longer ecm: :p

1870:

8030 A605A400 34625D129F349B4D54FCBF66EF0CD5A506123D2EFA4C4A81646668AC5B82CF17ED98AE90B4AD159C9ADF76D4FCBE5E6A7C43690B0D31A508633ABC74E8093B3232FF09C737DD36639D9B31A5DBB9EEB9077A45E4E062D2AD64950E35371AE37D37EF3894E40F10DBF1A56463D5456C67B696BE21E207CBDE1CC9AA3B28C9F5F0F968AA177E42F466CBF5F9F260FCC9BDB11B54B2139F66281C297246DE82093384E848
8130 A605A400 FF1E7B046BCB84A030AE865C09B38A02501FDA961FF72E5986AB24804B3E973BE6ACC3B1783F57AC73653CAA04EAAD4CCBB6C1943BB0B840FFA42FAAB7C4D2FD3AFA6372842C501C8BE89A5062AC6295F09D1A8EBC73252A9CC4BF2C9EDAEE3DB15951FF337B7E648E24C7B368E99ABE9343F1C214DD05BA865115A7DDE2A14B9818DF261F775EC328FFB3412EFA3C98F84F5430A0E6FA2DB2292AA9A238280538A41E

8030 (A6 len). (05:nano payload). A4:payload len 00 we have also new nano 05 there
Is very easy fix new ecm on oscam... 😁
 

schwarzekatze

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Is very easy fix new ecm on oscam... 😁
well i dont think so
offcourse we could just imagine there now but from my opinion longer ecm meant more encryption processing
altrought maybe kudelsky bonus is not activated in tivushit r450 yet 😂
 

Benfica200

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Your wrong, this not have nothing new only need make some tricks to get ecm with ecw
 

Benfica200

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well i dont think so
offcourse we could just imagine there now but from my opinion longer ecm meant more encryption processing
altrought maybe kudelsky bonus is not activated in tivushit r450 yet 😂
Tivusat DNASP450 card reply with flag5c
 

leandrotsampa

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i didnt dig deep how it exactly works but basically from my opinion is just otp key matter

from my opinion provider A have root key AABBFF and its smartcards have same key

now when provider A smartcard receive nuid BBAACCFF it calculate SCK key from BBAACCFF+AABBFF = ECW encrypt dcw with sck calculated from obffuscated BBAACCFF+AABBFF value

in stb side cpu calculate same sck key from BBAACCFF+AABBFF it just does ecw decrypt , whether smartcard does dcw encrypt

now provider B doing exactly same with one exception - with the different otp key:

root key CCBBAA:

FFDDAACC+CCBBAA = ECW encrypt dcw smartcard side and dcw decrypt stb cpu side

it so called global dcw pairing closed to 1 provider
it is tied to 1 provider because obffuscated sck values have been calculated from unique otp key so even if you send provider A nuid to provider B smartcard it would calculate you wrong ecw because otp_key calculated sck would not match

in STB side, key it's not calculated it's decypted.
Key is generated in factory and writed to STB, like others keys inside.
 
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schwarzekatze

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in STB side, key it's not calculated it's decypted.
Key is generated in factory and writed to STB, like others keys inside.
you have decrypted ecwpk keys from stb flash or from stb-emm by using result of otp_key+nuid calculation which is usually known as sck key
you are talking about flash keys me about cpu keys
these keys or key is calculated inside cpu and is used for decrypt ecwpk it is not outside so this is stb side , and this is calculation which include suposedly decryption or encryption also de-obffuscation we didnt know exact formula just some notes from public keyladder papers

@Benfica
dont see yours quote:
Code:
You don't have permission to view the code content.

 
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Benfica200

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you have decrypted ecwpk keys from stb flash or from stb-emm by using result of otp_key+nuid calculation which is usually known as sck key
you are talking about flash keys me about cpu keys
these keys or key is calculated inside cpu and is used for decrypt ecwpk it is not outside so this is stb side , and this is calculation which include suposedly decryption or encryption also de-obffuscation we didnt know exact formula just some notes from public keyladder papers

@Benfica
dont see yours quote:
Code:
You don't have permission to view the code content.
(ecm) get cw for ecm:2021/05/18 18:03:47 4B759F3E c (ecm) 80 30 A6 05 A - Pastebin.com
 
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