Function at 0x420290
Capabilities:
Compute adler32 checksum

Disassembly:
push ebp
mov ebp, esp
sub esp, 0x20
push ebx
push esi
push edi
mov edi, edx
mov ebx, ecx
movzx esi, byte [edi]
movzx eax, byte [edi + 1]
shl esi, 8
add esi, eax
movzx eax, byte [edi + 2]
shl esi, 8
add esi, eax
movzx eax, byte [edi + 3]
shl esi, 8
add esi, eax
cmp esi, 0x57bc0000
jne 0x4204f6
movzx ecx, byte [edi + 4]
movzx eax, byte [edi + 5]
shl ecx, 8
add ecx, eax
movzx eax, byte [edi + 6]
shl ecx, 8
add ecx, eax
movzx eax, byte [edi + 7]
shl ecx, 8
add ecx, eax
jne 0x4204f6
movzx ecx, byte [edi + 8]
movzx eax, byte [edi + 9]
shl ecx, 8
add ecx, eax
mov dword [0x46bcb8], edi
movzx eax, byte [edi + 0xa]
shl ecx, 8
add ecx, eax
mov dword [0x46bcc0], ebx
movzx eax, byte [edi + 0xb]
add edi, 0x10
shl ecx, 8
add ecx, eax
mov dword [0x46bcc4], ebx
mov dword [ebp - 0x1c], ecx
lea esi, [ecx + ebx]
mov ecx, edi
mov dword [0x46bcbc], esi
call fcn.00420660
mov dword [ebp - 0x18], eax
cmp eax, edi
je 0x420362
nop word [eax + eax]
cmp dword [0x46bcc4], esi
ja 0x4204f6
mov ecx, eax
mov esi, eax
call fcn.00420660
cmp eax, esi
mov dword [ebp - 0x18], eax
mov esi, dword [0x46bcbc]
jne 0x420340
cmp byte [eax], 5
jne 0x4204f6
cmp byte [eax + 1], 0xfa
jne 0x4204f6
cmp dword [0x46bcc4], esi
jne 0x4204f6
mov esi, dword [ebp - 0x1c]
mov eax, 0x5e6ea9af
mul esi
xor edi, edi
mov dword [ebp - 0x14], esi
shr edx, 0xb
mov ecx, 1
imul eax, edx, 0x15b0
mov edx, esi
mov dword [ebp - 0xc], edi
sub edx, eax
mov dword [ebp - 4], edx
test esi, esi
je 0x4204c1
xor esi, esi
cmp edx, 7
jbe 0x420412
mov eax, 7
sub eax, ebx
mov dword [ebp - 0x10], eax
movzx eax, byte [ebx]
add esi, 8
add ecx, eax
movzx eax, byte [ebx + 1]
add edi, ecx
add ecx, eax
movzx eax, byte [ebx + 2]
add edi, ecx
add ecx, eax
movzx eax, byte [ebx + 3]
add edi, ecx
add ecx, eax
movzx eax, byte [ebx + 4]
add edi, ecx
add ecx, eax
movzx eax, byte [ebx + 5]
add edi, ecx
add ecx, eax
movzx eax, byte [ebx + 6]
add edi, ecx
add ecx, eax
movzx eax, byte [ebx + 7]
add edi, ecx
add ebx, 8
add ecx, eax
mov eax, dword [ebp - 0x10]
add eax, ebx
add edi, ecx
cmp eax, edx
jb 0x4203c1
mov dword [ebp - 0xc], edi
mov eax, dword [ebp - 4]
xor edx, edx
mov dword [ebp - 0x10], 0
cmp esi, eax
jae 0x420486
sub eax, esi
cmp eax, 2
jb 0x420472
mov edx, dword [ebp - 4]
sub edx, esi
sub edx, 2
shr edx, 1
inc edx
lea eax, [esi + edx*2]
mov esi, dword [ebp - 0x10]
mov dword [ebp - 0x20], eax
mov edi, esi
nop
movzx eax, byte [ebx]
add ecx, eax
movzx eax, byte [ebx + 1]
add esi, ecx
add ebx, 2
add ecx, eax
add edi, ecx
sub edx, 1
jne 0x420440
mov eax, dword [ebp - 0x20]
mov dword [ebp - 8], edi
mov edi, dword [ebp - 0xc]
cmp eax, dword [ebp - 4]
jae 0x42047e
movzx eax, byte [ebx]
mov edx, dword [ebp - 8]
add ecx, eax
add edi, ecx
inc ebx
jmp 0x420481
movzx eax, byte [ebx]
mov esi, edx
add ecx, eax
add edi, ecx
inc ebx
jmp 0x420481
mov edx, dword [ebp - 8]
lea eax, [edx + esi]
add edi, eax
mov eax, 0x80078071
mul ecx
shr edx, 0xf
imul eax, edx, 0xffff000f
add ecx, eax
mov eax, 0x80078071
mul edi
shr edx, 0xf
imul eax, edx, 0xffff000f
mov edx, dword [ebp - 4]
add edi, eax
sub dword [ebp - 0x14], edx
mov edx, 0x15b0
mov dword [ebp - 0xc], edi
mov dword [ebp - 4], edx
jne 0x4203b0
mov edx, dword [ebp - 0x18]
shl edi, 0x10
add edi, ecx
movzx esi, byte [edx + 2]
movzx eax, byte [edx + 3]
shl esi, 8
add esi, eax
movzx eax, byte [edx + 4]
movzx edx, byte [edx + 5]
shl esi, 8
add esi, eax
shl esi, 8
add esi, edx
cmp edi, esi
jne 0x4204f6
mov eax, dword [ebp - 0x1c]
pop edi
pop esi
pop ebx
mov esp, ebp
pop ebp
ret
pop edi
pop esi
xor eax, eax
pop ebx
mov esp, ebp
pop ebp
ret