Function at 0x1400157f4
Capabilities:
Encode data using xor
Manually build aes constants

Disassembly:
mov rax, rsp
mov qword [rax + 8], rbx
mov qword [rax + 0x10], rsi
mov qword [rax + 0x18], rdi
mov qword [rax + 0x20], r12
push rbp
push r14
push r15
lea rbp, [rax - 0x718]
sub rsp, 0x800
xor r9d, r9d
lea r10, [rbp + 0x300]
mov r11d, 0x100
lea r8d, [r9 + 1]
mov eax, r8d
movzx ecx, r8b
mov dword [r10], r8d
and r8b, 0x80
lea r10, [r10 + 4]
mov dword [rsp + rax*4], r9d
mov al, cl
add al, al
movzx edx, al
xor edx, ecx
neg r8b
mov r8d, edx
sbb eax, eax
inc r9d
and eax, 0x1b
xor r8d, eax
cmp r9d, r11d
jl 0x14001582e
mov edx, 1
lea r8, [0x14026d830]
lea r9d, [rdx + 9]
mov eax, edx
mov dword [r8], edx
and al, 0x80
lea r8, [r8 + 4]
neg al
sbb ecx, ecx
add dl, dl
and ecx, 0x1b
movzx eax, dl
mov edx, ecx
xor edx, eax
sub r9, 1
jne 0x140015873
mov byte [0x14026d793], r9b
lea r10, [0x14026d231]
mov r9d, 1
mov byte [0x14026d230], 0x63
lea rbx, [rsp + 4]
lea rdi, sym.MZ_KYX__nCiq_dRpf_LPp:j::J6hH:2AMD_t54D_hAaa
mov eax, 0xff
sub eax, dword [rbx]
lea rbx, [rbx + 4]
cdqe
mov r8d, dword [rbp + rax*4 + 0x300]
mov ecx, r8d
sar ecx, 7
lea eax, [r8 + r8]
or ecx, eax
movzx edx, cl
mov al, dl
xor r8d, edx
add al, al
shr edx, 7
movzx ecx, al
or ecx, edx
mov al, cl
xor r8d, ecx
add al, al
shr ecx, 7
movzx edx, al
or edx, ecx
mov al, dl
add al, al
movzx ecx, al
mov eax, edx
shr eax, 7
or ecx, eax
xor ecx, 0x63
xor ecx, edx
xor r8d, ecx
movsxd rax, r8d
mov byte [r10], r8b
inc r10
mov byte [rax + rdi + 0x26d730], r9b
inc r9d
cmp r9d, r11d
jl 0x1400158bb
mov rsi, qword [rsp + 0x38]
xor r10d, r10d
mov r14, qword [rsp + 0x34]
mov r15, qword [rsp + 0x2c]
mov r12, qword [rsp + 0x24]
movzx r8d, byte [r10 + rdi + 0x26d230]
mov eax, r8d
and al, 0x80
neg al
mov al, r8b
sbb edx, edx
add al, al
movzx ecx, al
and edx, 0x1b
xor edx, ecx
mov eax, edx
xor eax, r8d
shl eax, 8
xor eax, r8d
shl eax, 8
xor eax, r8d
shl eax, 8
xor eax, edx
mov ecx, eax
mov dword [rdi + r10*4 + 0x26ec60], eax
shl eax, 8
shr ecx, 0x18
or ecx, eax
mov eax, ecx
mov dword [rdi + r10*4 + 0x26e860], ecx
shr eax, 0x18
shl ecx, 8
or eax, ecx
mov dword [rdi + r10*4 + 0x26dc60], eax
ror eax, 0x18
mov dword [rdi + r10*4 + 0x26d860], eax
movzx eax, byte [r10 + rdi + 0x26d730]
test al, al
je 0x140015a74
mov ecx, dword [rsp + rax*4]
mov r8d, eax
add ecx, r15d
mov eax, 0x80808081
imul ecx
add edx, ecx
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 + r8*4]
add ecx, r14d
mov r9d, dword [rbp + rax*4 + 0x300]
mov eax, 0x80808081
imul ecx
add edx, ecx
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 + r8*4]
add ecx, r12d
mov ebx, dword [rbp + rax*4 + 0x300]
mov eax, 0x80808081
imul ecx
add edx, ecx
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 + r8*4]
add ecx, esi
mov edi, dword [rbp + rax*4 + 0x300]
mov eax, 0x80808081
imul ecx
add edx, ecx
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 [rbp + rax*4 + 0x300]
jmp 0x140015a7d
xor r9d, r9d
xor ebx, ebx
xor edi, edi
xor ecx, ecx
shl r9d, 8
xor r9d, ebx
shl r9d, 8
xor r9d, edi
lea rdi, sym.MZ_KYX__nCiq_dRpf_LPp:j::J6hH:2AMD_t54D_hAaa
shl r9d, 8
xor r9d, ecx
mov ecx, r9d
mov dword [rdi + r10*4 + 0x26e460], r9d
shr ecx, 0x18
shl r9d, 8
or ecx, r9d
mov eax, ecx
mov dword [rdi + r10*4 + 0x26e060], ecx
shr eax, 0x18
shl ecx, 8
or eax, ecx
mov dword [rdi + r10*4 + 0x26f060], eax
ror eax, 0x18
mov dword [rdi + r10*4 + 0x26d330], eax
inc r10
sub r11, 1
jne 0x140015943
lea r11, [rsp + 0x800]
mov rbx, qword [r11 + 0x20]
mov rsi, qword [r11 + 0x28]
mov rdi, qword [r11 + 0x30]
mov r12, qword [r11 + 0x38]
mov rsp, r11
pop r15
pop r14
pop rbp
ret