Some info about rockey for who needs to parse usbtrace logs

Decryption routines of R4 series. Reading its SDK is a must for the rest. 
Should I write a complete tutorial? A whole parser?

char command[25];
char response[25];


/*command and response arrays are from usb trace logs. You can find them after ** data ** lines. They must be 24 bytes long

char KEY=command[2];
processCommand(command[]);
processResponse(response[])



void processCommand(command[])
{
g(&command[0x9], &command[0x11]); // for r4 smart only
g(&command[0x2], &command[0x11]); // for r4 smart only

for (int i = 2; i < 25; i++) { command[i] ^= KEY; } 

for (int i = 0; i < 25; i++) { printf("%02X ", command[i]); }

}

void processResponse(response[])
{
f(&response[0x9], &response[0x11]); // for r4 smart only
f(&response[0x2], &response[0x11]); // for r4 smart only
for (int i = 2; i < 25; i++) { command[i] ^= KEY; }

for (int i = 0; i < 25; i++) { printf("%02X ", command[i]); }
}




int f(BYTE *P, BYTE *Q) // decryption from dongle/encryption in pc
{
__asm
{
pushad
mov     edx, P
mov     edi, Q
mov     ebp, edi
xor     ecx, ecx
sub     ebp, edx

loop_i :
xor     eax, eax

loop_j :
mov     bl, cl
or bl, al
add     bl, [eax + edi]
inc     eax
add[edx], bl
cmp     eax, 8
jl      short loop_j

xor     esi, esi

loop_k :
mov     al, [esi + edi]
dec     al
imul    cl
xor[edx], al
inc     esi
cmp     esi, 8
jl      short loop_k
mov     al, [edx + ebp]
shl     al, cl
inc     ecx
inc     edx
xor[edx - 1], al
cmp     ecx, 8
jl      short loop_i
popad
}
// Return with result in EAX  
}


int g(BYTE *P, BYTE *Q) // decryption from pc, encryption in dongle
{
__asm
{
pushad
mov     edx, P
mov     edi, Q
mov     ebp, edi
xor     ecx, ecx
sub     ebp, edx

loop_i :

mov     al, [edx + ebp]
shl     al, cl
xor[edx], al

xor     esi, esi

loop_k :
mov     al, [esi + edi]
dec     al
imul    cl
xor[edx], al
inc     esi
cmp     esi, 8

jl      short loop_k



xor     eax, eax

loop_j :
mov     bl, cl
or bl, al
add     bl, [eax + edi]
inc     eax
sub[edx], bl
cmp     eax, 8
jl      short loop_j

inc     ecx
inc     edx

cmp     ecx, 8
jl      short loop_i
popad


}
// Return with result in EAX  
}

please do, but be careful who you share your work, you might find it for sale, not from you.

ovis25 wrote:please do, but be careful who you share your work, you might find it for sale, not from you.

Thanks for warning, I ll do nothing about it. Keep it myself. Thanks