| 0,0 → 1,216 |
|---|
| ; Password handling in 7-Zip: "7zAES" filter (SHA256 + AES256). |
| ; Ported from C++ sources of 7-Zip (c) Igor Pavlov. |
| aes7z_decoder: |
| virtual at 0 |
| .outStream rb streamInfo.size |
| .inStream dd ? |
| .inLen dd ? |
| .inPtr dd ? |
| .bufRest dd ? |
| ; key data |
| .NumCyclesPower dd ? |
| .SaltSize dd ? |
| .Salt rb 16 |
| ; AES data |
| .iv rb 16 |
| .Key rb 32 |
| .nr dd ? |
| .KeyExpanded rb 32*15 |
| .size = $ |
| end virtual |
| |
| .fillBuf: |
| mov esi, [eax+.inPtr] |
| mov ebp, eax |
| add edi, [eax+.bufRest] |
| sub ecx, [eax+.bufRest] |
| js .rest1 |
| and [eax+.bufRest], 0 |
| .mainloop: |
| test ecx, ecx |
| jz .done |
| sub [ebp+.inLen], 16 |
| js .refill |
| .refilled: |
| push esi edi ecx |
| mov ebx, edi |
| lea edi, [ebp+.nr] |
| call aes_decode |
| pop ecx edi esi |
| mov eax, dword [ebp+.iv] |
| xor [edi], eax |
| lodsd |
| mov dword [ebp+.iv], eax |
| mov eax, dword [ebp+.iv+4] |
| xor [edi+4], eax |
| lodsd |
| mov dword [ebp+.iv+4], eax |
| mov eax, dword [ebp+.iv+8] |
| xor [edi+8], eax |
| lodsd |
| mov dword [ebp+.iv+8], eax |
| mov eax, dword [ebp+.iv+12] |
| xor [edi+12], eax |
| lodsd |
| mov dword [ebp+.iv+12], eax |
| add edi, 16 |
| sub ecx, 16 |
| jns .mainloop |
| .rest1: |
| neg ecx |
| mov [ebp+.bufRest], ecx |
| .done: |
| mov [ebp+.inPtr], esi |
| popad |
| ret |
| |
| .refill: |
| mov edx, [ebp+.inLen] |
| add edx, 16 |
| jnz .rest |
| js return.err |
| mov eax, [ebp+.inStream] |
| call fillBuf |
| mov edx, [eax+streamInfo.bufDataLen] |
| test edx, edx |
| jz return.err |
| mov esi, [eax+streamInfo.bufPtr] |
| mov [ebp+.inLen], edx |
| sub [ebp+.inLen], 16 |
| jns .refilled |
| .rest: |
| ; ASSERT([eax+streamInfo.fullSize] == 0); |
| sub edx, ecx |
| jb return.err |
| add ecx, edx |
| rep movsb |
| mov [ebp+.bufRest], edx |
| jmp .done |
| |
| aes7z_get_buf_size: |
| mov eax, aes7z_decoder.size |
| mov edx, 0x4000 |
| ret |
| |
| aes7z_init_decoder: |
| ; zero all |
| xor eax, eax |
| mov [ebp+aes7z_decoder.inLen], eax |
| mov [ebp+aes7z_decoder.bufRest], eax |
| mov [ebp+aes7z_decoder.NumCyclesPower], eax |
| mov [ebp+aes7z_decoder.SaltSize], eax |
| lea edi, [ebp+aes7z_decoder.Salt] |
| push 8 |
| pop ecx |
| rep stosd ; zero .Salt and .iv |
| mov [ebp+streamInfo.fillBuf], aes7z_decoder.fillBuf |
| ; parse parameters |
| cmp dword [esi-4], eax |
| jz .parok ; no parameters - OK |
| lodsb |
| mov cl, al |
| and al, 0x3F |
| mov byte [ebp+aes7z_decoder.NumCyclesPower], al |
| test cl, 0xC0 |
| jz .parok |
| test cl, 0x80 |
| setnz byte [ebp+aes7z_decoder.SaltSize] |
| shr cl, 6 |
| and ecx, 1 |
| cmp dword [esi-1-4], 2 |
| jb return.err |
| lodsb |
| mov dl, al |
| shr al, 4 |
| add byte [ebp+aes7z_decoder.SaltSize], al |
| and edx, 0xF |
| add ecx, edx |
| lea edx, [ecx+2] |
| push ecx |
| mov ecx, [ebp+aes7z_decoder.SaltSize] |
| add edx, ecx |
| cmp dword [esi-2-4], edx |
| jb return.err |
| lea edi, [ebp+aes7z_decoder.Salt] |
| rep movsb |
| pop ecx |
| lea edi, [ebp+aes7z_decoder.iv] |
| rep movsb |
| .parok: |
| test bl, bl |
| jnz .ret ; if reinitializing - all calculations have been already done |
| call query_password |
| jz return.clear |
| ;.CalculateDigest: |
| mov cl, byte [ebp+aes7z_decoder.NumCyclesPower] |
| cmp cl, 0x3F |
| jnz .sha |
| lea edi, [ebp+aes7z_decoder.Key] |
| mov ecx, [ebp+aes7z_decoder.SaltSize] |
| push 32 |
| pop edx |
| sub edx, ecx |
| lea esi, [ebp+aes7z_decoder.Salt] |
| rep movsb |
| mov ecx, [password_size] |
| add ecx, ecx |
| cmp ecx, edx |
| jbe @f |
| mov ecx, edx |
| @@: |
| sub edx, ecx |
| mov esi, password_unicode |
| rep movsb |
| mov ecx, edx |
| xor eax, eax |
| rep stosb |
| jmp .setkey |
| .sha: |
| cmp cl, 32 |
| jb .normal |
| push 1 |
| shl dword [esp], cl |
| push 0 |
| jmp @f |
| .normal: |
| push 0 |
| push 1 |
| shl dword [esp], cl |
| @@: |
| push 0 |
| push 0 |
| call sha256_init |
| .loop: |
| lea esi, [ebp+aes7z_decoder.Salt] |
| mov edx, [ebp+aes7z_decoder.SaltSize] |
| call sha256_update |
| mov esi, password_unicode |
| mov edx, [password_size] |
| add edx, edx |
| call sha256_update |
| mov esi, esp |
| push 8 |
| pop edx |
| call sha256_update |
| mov esi, esp |
| dec esi |
| @@: |
| inc esi |
| inc byte [esi] |
| jz @b |
| sub dword [esp+8], 1 |
| sbb dword [esp+12], 0 |
| mov eax, [esp+8] |
| or eax, [esp+12] |
| jnz .loop |
| lea edi, [ebp+aes7z_decoder.Key] |
| call sha256_final |
| add esp, 16 |
| .setkey: |
| lea esi, [ebp+aes7z_decoder.Key] |
| push 8 |
| pop edx ; 7z uses 256-bit keys |
| lea edi, [ebp+aes7z_decoder.nr] |
| call aes_setkey |
| .ret: |
| ret |