Function at 0x1400878b0
Capabilities:
Encode data using xor
Manually build aes constants

Disassembly:
mov qword [rsp + 8], rbx
mov qword [rsp + 0x10], rbp
mov qword [rsp + 0x18], rsi
mov qword [rsp + 0x20], rdi
push r12
push r14
push r15
sub rsp, 0x800
mov r9d, 1
lea r10, [rsp + 0x400]
mov edx, r9d
xor r8d, r8d
mov r11d, 0x100
nop dword [rax + rax]
mov eax, edx
mov dword [r10], edx
lea r10, [r10 + 4]
mov dword [rsp + rax*4], r8d
mov eax, edx
and al, 0x80
neg al
lea eax, [rdx + rdx]
sbb ecx, ecx
inc r8d
and ecx, 0x1b
xor ecx, eax
xor ecx, edx
movzx edx, cl
cmp r8d, r11d
jl 0x1400878f0
mov edx, r9d
lea r8, [0x1401177f0]
mov r10d, 0xa
nop word [rax + rax]
mov eax, edx
mov dword [r8], edx
and al, 0x80
lea r8, [r8 + 4]
neg al
lea eax, [rdx + rdx]
sbb ecx, ecx
and ecx, 0x1b
xor ecx, eax
movzx edx, cl
sub r10, r9
jne 0x140087930
mov byte [0x140117753], r10b
lea rbx, [rsp + 4]
lea r10, [0x1401171f1]
mov byte [0x1401171f0], 0x63
lea r12, [0x140000000]
mov eax, 0xff
lea r10, [r10 + 1]
sub eax, dword [rbx]
lea rbx, [rbx + 4]
cdqe
mov r8d, dword [rsp + rax*4 + 0x400]
mov ecx, r8d
sar ecx, 7
lea eax, [r8 + r8]
or ecx, eax
movzx eax, cl
xor r8d, eax
mov ecx, eax
shr ecx, 7
add eax, eax
or ecx, eax
movzx eax, cl
xor r8d, eax
mov ecx, eax
shr ecx, 7
add eax, eax
or ecx, eax
movzx edx, cl
mov ecx, edx
shr ecx, 7
lea eax, [rdx + rdx]
or ecx, eax
xor ecx, 0x63
movzx eax, cl
xor eax, edx
xor r8d, eax
movsxd rax, r8d
mov byte [r10 - 1], r8b
mov byte [rax + r12 + 0x1176f0], r9b
inc r9d
cmp r9d, r11d
jl 0x140087970
mov rsi, qword [rsp + 0x38]
xor r10d, r10d
mov rbp, qword [rsp + 0x34]
mov r14, qword [rsp + 0x2c]
mov r15, qword [rsp + 0x24]
nop dword [rax]
movzx edx, byte [r10 + r12 + 0x1171f0]
mov eax, edx
and al, 0x80
neg al
lea eax, [rdx + rdx]
sbb ecx, ecx
and ecx, 0x1b
xor ecx, eax
movzx eax, cl
mov ecx, eax
xor ecx, edx
shl ecx, 8
xor ecx, edx
shl ecx, 8
xor ecx, edx
shl ecx, 8
xor ecx, eax
movzx eax, byte [r10 + r12 + 0x1176f0]
mov dword [r12 + r10*4 + 0x118c20], ecx
rol ecx, 8
mov dword [r12 + r10*4 + 0x118820], ecx
rol ecx, 8
mov dword [r12 + r10*4 + 0x117c20], ecx
rol ecx, 8
mov dword [r12 + r10*4 + 0x117820], ecx
test al, al
je 0x140087b26
mov ecx, dword [rsp + rax*4]
mov r9d, eax
add ecx, r14d
mov eax, 0x80808081
imul ecx
mov r8d, dword [rsp + r9*4]
add edx, ecx
add r8d, ebp
sar edx, 7
mov eax, edx
shr eax, 0x1f
add edx, eax
imul eax, edx, 0xff
sub ecx, eax
movsxd rax, ecx
mov ecx, dword [rsp + rax*4 + 0x400]
mov eax, 0x80808081
imul r8d
add edx, r8d
sar edx, 7
mov eax, edx
shr eax, 0x1f
add edx, eax
imul eax, edx, 0xff
sub r8d, eax
movsxd rax, r8d
mov r8d, dword [rsp + r9*4]
add r8d, r15d
mov ebx, dword [rsp + rax*4 + 0x400]
mov eax, 0x80808081
imul r8d
add edx, r8d
sar edx, 7
mov eax, edx
shr eax, 0x1f
add edx, eax
imul eax, edx, 0xff
sub r8d, eax
movsxd rax, r8d
mov r8d, dword [rsp + r9*4]
add r8d, esi
mov edi, dword [rsp + rax*4 + 0x400]
mov eax, 0x80808081
imul r8d
add edx, r8d
sar edx, 7
mov eax, edx
shr eax, 0x1f
add edx, eax
imul eax, edx, 0xff
sub r8d, eax
movsxd rax, r8d
mov edx, dword [rsp + rax*4 + 0x400]
jmp 0x140087b2e
xor ecx, ecx
xor ebx, ebx
xor edi, edi
xor edx, edx
shl ecx, 8
xor ecx, ebx
shl ecx, 8
xor ecx, edi
shl ecx, 8
xor ecx, edx
mov dword [r12 + r10*4 + 0x118420], ecx
rol ecx, 8
mov dword [r12 + r10*4 + 0x118020], ecx
rol ecx, 8
mov dword [r12 + r10*4 + 0x119020], ecx
rol ecx, 8
mov dword [r12 + r10*4 + 0x1172f0], ecx
inc r10
sub r11, 1
jne 0x140087a00
lea r11, [rsp + 0x800]
mov rbx, qword [r11 + 0x20]
mov rbp, qword [r11 + 0x28]
mov rsi, qword [r11 + 0x30]
mov rdi, qword [r11 + 0x38]
mov rsp, r11
pop r15
pop r14
pop r12
ret