Streamfab/main.cpp

// Online C++ compiler to run C++ program online
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string.h>


typedef unsigned long long undefined8;
typedef unsigned long undefined4;
typedef unsigned char undefined;
typedef unsigned char byte;
typedef unsigned long ulong;
typedef unsigned int uint;


void hex_to_bytes(char* input, char* output, ulong buffer_size) {
    /*
    Hex to Bytes -- Returned as char* (0-255)

    Parameters:
        input: Input hex string data
        output: Output bytes buffer
        buffer_size: Output buffer size
    */
    size_t len;
    ulong i;

    len = strlen(input);
    if (len + 1 >> 1 <= buffer_size) {
        for (i = 0; i < len; i = i + 2) {
            sscanf(input + i, "%2hhx", output + (i >> 1));
        }
    }
    return;
}

void bytes_to_hex(char* input, char* output, ulong buffer_size) {
    ulong i;

    for (i = 0; i < buffer_size; i = i + 1) {
        sprintf((char*)(output + i * 2), "%02x", (ulong) * (byte*)(input + i));
    }

    return;
}

void _modkey2key(uint* mod, uint* tok) {
    /* Secure function to undo modifications to "mod" key (In-place). */
    // - when doing pointer arithmetic, make sure to use (long long) and not (long) as we
    //   are compiling for a 64-bit platform, not 32-bit.
    long local_50;
    long local_48;
    byte local_31;
    byte local_30;
    byte local_2f;
    short local_2e;
    uint local_28;
    uint local_24;
    int local_20;
    int local_1c;
    short local_18;
    byte local_15;

    int i;
    uint tok_xor = *tok ^ 0x2a2e3706;
    uint mod_deref = *mod;

    for (i = 1; i <= 3; i = i + 1) {
        tok_xor = tok_xor ^ mod_deref;

        local_2e = (short)(tok_xor >> 0x10);
        local_18 = (short)tok_xor;
        local_2f = (byte)(tok_xor >> 0x10);
        local_30 = (byte)(local_2e >> 5) & 0x1f;
        local_31 = (byte)((int)tok_xor >> 0x1a);

        tok[i] = tok[i] << (-local_31 & 0x1f) | tok[i] >> (local_31 & 0x1f);
        tok_xor = (int)(local_2e >> 0xf) ^
                  (tok_xor >> (local_2f & 0x1f) | tok_xor << (-local_2f & 0x1f)) ^
                  tok[i];

        byte t_l = *(byte*)((long long)&tok_xor + (tok[i] - i & 3)) >> 3;
        byte t_r = -(*(byte*)((long long)&tok_xor + (tok[i] - i & 3)) >> 3) & 0x1f;
        mod[i] = mod[i] << t_l | mod[i] >> t_r;
        
        for (local_20 = 0; local_20 < 4; local_20 = local_20 + 1) {
            local_15 = 0;
            for (local_1c = 0; local_1c < 4; local_1c = local_1c + 1) {
                if ((int)((int)local_18 & 3U) < local_1c) {
                    local_24 = 0xff;
                }
                else {
                    local_24 = (uint) * (byte*)((long long)&tok_xor + (ulong)(local_1c + local_20 & 3));
                }
                local_15 = local_15 ^ (byte)local_24;
            }
            for (local_1c = 0; local_1c < 4; local_1c = local_1c + 1) {
                if ((int)((int)(local_18 >> 2) & 3U) < local_1c) {
                    local_28 = 0xff;
                }
                else {
                    local_28 = (uint)local_15;
                }
                *(byte*)((long long)mod + (int)(i * 4 + (local_1c + local_20 & 3U))) =
                    *(byte*)((long long)mod + (int)(i * 4 + (local_1c + local_20 & 3U))) ^
                    (byte)local_28;
            }
            local_18 = local_18 >> 4;
        }
        mod_deref = mod[i];
        local_50 = (long)i;
        mod[i] = mod[i] << local_30 | mod[i] >> (-local_30 & 0x1f);
    }

    return;
}

char* modkey2key(char* mod, char* tok) {
    size_t key_len;
    char key[32];
    char mod_bytes[16];
    char tok_bytes[16];
    char* key_buffer;

    hex_to_bytes(mod, mod_bytes, 0x10);
    hex_to_bytes(tok, tok_bytes, 0x10);

    _modkey2key((uint*)&mod_bytes, (uint*)&tok_bytes);

    bytes_to_hex(mod_bytes, key, 0x10);

    // copy key to new buffer as `key` is allocated on the func stack
    // it would get cleared on return if we don't do this
    key_len = strlen(key);
    key_buffer = (char*)malloc(key_len + 1);  // +1 for null terminator
    strcpy(key_buffer, key);

    return key_buffer;
}

int main(int argc, char* argv[]) {
    //char mod[] = "dadcf4783dd85c97bcf1d7b90cc55d51";
    //char tok[] = "cab66d47305016a723586c4778c0b521";
    char* mod = argv[1];
    char* tok = argv[2];

    //std::cout << "mod: " << mod << std::endl;
    //std::cout << "tok: " << tok << std::endl;

    char* key = modkey2key(mod, tok);

    std::cout << key << std::endl;
    // key == "dadcf478e4a50085f22bb673864b0ae9"

    return 0;
}