From bacc2ca17e6b3548946e6605e83e0898ad111834 Mon Sep 17 00:00:00 2001 From: InvoxiPlayGames Date: Sat, 12 Aug 2023 22:12:46 +0100 Subject: [PATCH] wip xbox xsv builder --- .gitignore | 8 ++ README.md | 4 +- gci_builder_src/Makefile | 2 +- xbox_src/Makefile | 18 +++ xbox_src/hmac_sha1.c | 43 +++++++ xbox_src/hmac_sha1.h | 29 +++++ xbox_src/sha1.c | 256 +++++++++++++++++++++++++++++++++++++++ xbox_src/sha1.h | 31 +++++ xbox_src/xsv_builder.c | 155 ++++++++++++++++++++++++ 9 files changed, 543 insertions(+), 3 deletions(-) create mode 100644 xbox_src/Makefile create mode 100644 xbox_src/hmac_sha1.c create mode 100644 xbox_src/hmac_sha1.h create mode 100644 xbox_src/sha1.c create mode 100644 xbox_src/sha1.h create mode 100644 xbox_src/xsv_builder.c diff --git a/.gitignore b/.gitignore index 0181592..5c5d107 100644 --- a/.gitignore +++ b/.gitignore @@ -2,10 +2,18 @@ *.bin *.elf *.o +ernie +# wip shellcode +*.asm +# output artifacts *.gci +*.xsv +*.xbx +*.xbe # executable artifacts *.exe gci_builder +xsv_builder *.dSYM # other stuff *.zip diff --git a/README.md b/README.md index d8f7095..67f0b15 100644 --- a/README.md +++ b/README.md @@ -38,8 +38,8 @@ If you only want to build for a specific region, type `make usa` or `make eur`. ## License -The memory card loader and GCI builder are licensed under the GNU General Public License version 2. See attached +The GameCube memory card loader and GCI builder are licensed under the GNU General Public License version 2. See attached LICENSE file for more details. -This chain uses FIX94's [gc-exploit-common-loader](https://github.com/FIX94/gc-exploit-common-loader), also licensed +The GameCube chain uses FIX94's [gc-exploit-common-loader](https://github.com/FIX94/gc-exploit-common-loader), also licensed under GPLv2. diff --git a/gci_builder_src/Makefile b/gci_builder_src/Makefile index 1c5c823..72728ab 100644 --- a/gci_builder_src/Makefile +++ b/gci_builder_src/Makefile @@ -8,7 +8,7 @@ SRC := gci_builder.c default: all $(TARGET): $(SRC) - $(CC) $(CFLAGS) -o $@ $< + $(CC) $(CFLAGS) -o $@ $^ .PHONY: all all: $(TARGET) diff --git a/xbox_src/Makefile b/xbox_src/Makefile new file mode 100644 index 0000000..db97536 --- /dev/null +++ b/xbox_src/Makefile @@ -0,0 +1,18 @@ +TARGET := xsv_builder +ifeq ($(OS),Windows_NT) + TARGET := $(addsuffix .exe,$(TARGET)) +endif + +SRC := sha1.c hmac_sha1.c xsv_builder.c + +default: all + +$(TARGET): $(SRC) + $(CC) $(CFLAGS) -o $@ $^ + +.PHONY: all +all: $(TARGET) + +.PHONY: clean +clean: + @-rm -f $(TARGET) diff --git a/xbox_src/hmac_sha1.c b/xbox_src/hmac_sha1.c new file mode 100644 index 0000000..8071a35 --- /dev/null +++ b/xbox_src/hmac_sha1.c @@ -0,0 +1,43 @@ +#include +#include +#include +#include "sha1.h" +#include "hmac_sha1.h" + +void HMAC_SHA1_Init(HMAC_SHA1_CTX *context, const uint8_t *key, size_t key_len) { + // upper limit on the key length + if (key_len > 0x40) key_len = 0x40; + // prepare the sha1 contexts + SHA1_Init(&context->state[0]); + SHA1_Init(&context->state[1]); + // prepare the key buffers to initialise the sha1 contexts + uint8_t key_buf_1[0x40] = {0}; + uint8_t key_buf_2[0x40] = {0}; + memcpy(key_buf_1, key, key_len); + memcpy(key_buf_2, key, key_len); + for (int i = 0; i < 0x40; i++) { + key_buf_1[i] ^= 0x36; + key_buf_2[i] ^= 0x5C; + } + SHA1_Update(&context->state[0], key_buf_1, 0x40); + SHA1_Update(&context->state[1], key_buf_2, 0x40); +} + +void HMAC_SHA1_Update(HMAC_SHA1_CTX *context, const uint8_t *data, const size_t len) { + SHA1_Update(&context->state[0], data, len); +} + +void HMAC_SHA1_Final(HMAC_SHA1_CTX *context, uint8_t digest[SHA1_DIGEST_SIZE]) { + uint8_t hash[0x14]; + SHA1_Final(&context->state[0], hash); + // feed the final hash of the first state into the second state + SHA1_Update(&context->state[1], hash, sizeof(hash)); + SHA1_Final(&context->state[1], digest); +} + +void HMAC_SHA1(const uint8_t *key, size_t key_len, const uint8_t *data, const size_t len, uint8_t digest[SHA1_DIGEST_SIZE]) { + HMAC_SHA1_CTX ctx = {0}; + HMAC_SHA1_Init(&ctx, key, key_len); + HMAC_SHA1_Update(&ctx, data, len); + HMAC_SHA1_Final(&ctx, digest); +} diff --git a/xbox_src/hmac_sha1.h b/xbox_src/hmac_sha1.h new file mode 100644 index 0000000..683c675 --- /dev/null +++ b/xbox_src/hmac_sha1.h @@ -0,0 +1,29 @@ +#ifndef _HMAC_SHA1_H +#define _HMAC_SHA1_H + +#include +#include +#include "sha1.h" + +#ifdef __cplusplus +extern "C" +{ +#endif + +typedef struct { + SHA1_CTX state[2]; +} HMAC_SHA1_CTX; + +#define SHA1_DIGEST_SIZE 20 + +void HMAC_SHA1_Init(HMAC_SHA1_CTX *context, const uint8_t *key, size_t key_len); +void HMAC_SHA1_Update(HMAC_SHA1_CTX *context, const uint8_t *data, const size_t len); +void HMAC_SHA1_Final(HMAC_SHA1_CTX *context, uint8_t digest[SHA1_DIGEST_SIZE]); + +void HMAC_SHA1(const uint8_t *key, size_t key_len, const uint8_t *data, const size_t len, uint8_t digest[SHA1_DIGEST_SIZE]); + +#ifdef __cplusplus +} +#endif + +#endif // _HMAC_SHA1_H diff --git a/xbox_src/sha1.c b/xbox_src/sha1.c new file mode 100644 index 0000000..e46fe69 --- /dev/null +++ b/xbox_src/sha1.c @@ -0,0 +1,256 @@ +/* +SHA-1 in C +By Steve Reid +100% Public Domain + +----------------- +Modified 7/98 +By James H. Brown +Still 100% Public Domain + +Corrected a problem which generated improper hash values on 16 bit machines +Routine SHA1Update changed from + void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int +len) +to + void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned +long len) + +The 'len' parameter was declared an int which works fine on 32 bit machines. +However, on 16 bit machines an int is too small for the shifts being done +against +it. This caused the hash function to generate incorrect values if len was +greater than 8191 (8K - 1) due to the 'len << 3' on line 3 of SHA1Update(). + +Since the file IO in main() reads 16K at a time, any file 8K or larger would +be guaranteed to generate the wrong hash (e.g. Test Vector #3, a million +"a"s). + +I also changed the declaration of variables i & j in SHA1Update to +unsigned long from unsigned int for the same reason. + +These changes should make no difference to any 32 bit implementations since +an +int and a long are the same size in those environments. + +-- +I also corrected a few compiler warnings generated by Borland C. +1. Added #include for exit() prototype +2. Removed unused variable 'j' in SHA1Final +3. Changed exit(0) to return(0) at end of main. + +ALL changes I made can be located by searching for comments containing 'JHB' +----------------- +Modified 8/98 +By Steve Reid +Still 100% public domain + +1- Removed #include and used return() instead of exit() +2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall) +3- Changed email address from steve@edmweb.com to sreid@sea-to-sky.net + +----------------- +Modified 4/01 +By Saul Kravitz +Still 100% PD +Modified to run on Compaq Alpha hardware. + +----------------- +Modified 07/2002 +By Ralph Giles +Still 100% public domain +modified for use with stdint types, autoconf +code cleanup, removed attribution comments +switched SHA1Final() argument order for consistency +use SHA1_ prefix for public api +move public api to sha1.h +*/ + +/* +Test Vectors (from FIPS PUB 180-1) +"abc" + A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D +"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq" + 84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1 +A million repetitions of "a" + 34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F +*/ + +#define SHA1HANDSOFF + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include +#include + +#include "sha1.h" + +void SHA1_Transform(uint32_t state[5], const uint8_t buffer[64]); + +#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits)))) + +/* blk0() and blk() perform the initial expand. */ +/* I got the idea of expanding during the round function from SSLeay */ +/* FIXME: can we do this in an endian-proof way? */ +#ifdef WORDS_BIGENDIAN +#define blk0(i) block->l[i] +#else +#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \ + |(rol(block->l[i],8)&0x00FF00FF)) +#endif +#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \ + ^block->l[(i+2)&15]^block->l[i&15],1)) + +/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */ +#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30); +#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30); +#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30); +#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30); +#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30); + +#ifdef VERBOSE /* SAK */ +void +SHAPrintContext(SHA1_CTX *context, char *msg) +{ + printf("%s (%d,%d) %08x %08x %08x %08x %08x\n", + msg, context->count[0], context->count[1], context->state[0], context->state[1], context->state[2], context->state[3], context->state[4]); +} +#endif /* VERBOSE */ + +/* Hash a single 512-bit block. This is the core of the algorithm. */ +void +SHA1_Transform(uint32_t state[5], const uint8_t buffer[64]) +{ + uint32_t a, b, c, d, e; + typedef union { + uint8_t c[64]; + uint32_t l[16]; + } CHAR64LONG16; + CHAR64LONG16 *block; + +#ifdef SHA1HANDSOFF + static uint8_t workspace[64]; + + block = (CHAR64LONG16 *) workspace; + memcpy(block, buffer, 64); +#else + block = (CHAR64LONG16 *) buffer; +#endif + + /* Copy context->state[] to working vars */ + a = state[0]; + b = state[1]; + c = state[2]; + d = state[3]; + e = state[4]; + + /* 4 rounds of 20 operations each. Loop unrolled. */ + R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3); + R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7); + R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11); + R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15); + R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19); + R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23); + R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27); + R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31); + R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35); + R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39); + R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43); + R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47); + R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51); + R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55); + R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59); + R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63); + R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67); + R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71); + R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75); + R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79); + + /* Add the working vars back into context.state[] */ + state[0] += a; + state[1] += b; + state[2] += c; + state[3] += d; + state[4] += e; + + /* Wipe variables */ + a = b = c = d = e = 0; +} + +/* SHA1Init - Initialize new context */ +void +SHA1_Init(SHA1_CTX *context) +{ + /* SHA1 initialization constants */ + context->state[0] = 0x67452301; + context->state[1] = 0xEFCDAB89; + context->state[2] = 0x98BADCFE; + context->state[3] = 0x10325476; + context->state[4] = 0xC3D2E1F0; + context->count[0] = context->count[1] = 0; +} + +/* Run your data through this. */ +void +SHA1_Update(SHA1_CTX *context, const uint8_t *data, const size_t len) +{ + size_t i, j; + +#ifdef VERBOSE + SHAPrintContext(context, "before"); +#endif + + j = (context->count[0] >> 3) & 63; + if ((context->count[0] += len << 3) < (len << 3)) + context->count[1]++; + context->count[1] += (len >> 29); + if ((j + len) > 63) { + memcpy(&context->buffer[j], data, (i = 64 - j)); + SHA1_Transform(context->state, context->buffer); + for (; i + 63 < len; i += 64) { + SHA1_Transform(context->state, data + i); + } + j = 0; + } else + i = 0; + memcpy(&context->buffer[j], &data[i], len - i); + +#ifdef VERBOSE + SHAPrintContext(context, "after "); +#endif +} + +/* Add padding and return the message digest. */ +void +SHA1_Final(SHA1_CTX *context, uint8_t digest[SHA1_DIGEST_SIZE]) +{ + uint32_t i; + uint8_t finalcount[8]; + + for (i = 0; i < 8; i++) { + finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)] + >> ((3 - (i & 3)) * 8)) & 255); /* Endian independent */ + } + SHA1_Update(context, (uint8_t *) "\200", 1); + while ((context->count[0] & 504) != 448) { + SHA1_Update(context, (uint8_t *) "\0", 1); + } + SHA1_Update(context, finalcount, 8); /* Should cause a SHA1_Transform() */ + for (i = 0; i < SHA1_DIGEST_SIZE; i++) { + digest[i] = (uint8_t) + ((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255); + } + + /* Wipe variables */ + i = 0; + memset(context->buffer, 0, 64); + memset(context->state, 0, 20); + memset(context->count, 0, 8); + memset(finalcount, 0, 8); /* SWR */ + +#ifdef SHA1HANDSOFF /* make SHA1Transform overwrite its own static vars */ + SHA1_Transform(context->state, context->buffer); +#endif +} diff --git a/xbox_src/sha1.h b/xbox_src/sha1.h new file mode 100644 index 0000000..0d2cbbc --- /dev/null +++ b/xbox_src/sha1.h @@ -0,0 +1,31 @@ +/* public api for steve reid's public domain SHA-1 implementation */ +/* this file is in the public domain */ + +#ifndef __SHA1_H +#define __SHA1_H + +#include +#include + +#ifdef __cplusplus +extern "C" +{ +#endif + +typedef struct { + uint32_t state[5]; + uint32_t count[2]; + uint8_t buffer[64]; +} SHA1_CTX; + +#define SHA1_DIGEST_SIZE 20 + +void SHA1_Init(SHA1_CTX *context); +void SHA1_Update(SHA1_CTX *context, const uint8_t *data, const size_t len); +void SHA1_Final(SHA1_CTX *context, uint8_t digest[SHA1_DIGEST_SIZE]); + +#ifdef __cplusplus +} +#endif + +#endif /* __SHA1_H */ diff --git a/xbox_src/xsv_builder.c b/xbox_src/xsv_builder.c new file mode 100644 index 0000000..a21fa4e --- /dev/null +++ b/xbox_src/xsv_builder.c @@ -0,0 +1,155 @@ +#include +#include +#include +#include +#include +#include +#include +#include "hmac_sha1.h" + +//#define SAVEGAME_DATA_LENGTH 0x2E4 +#define SAVEGAME_DATA_LENGTH 0x2048 + +// the length of the string before overriding eip is, theoretically, fair game to change whatever in +#define MAX_XOR_PAYLOAD_LENGTH 0x1FC + +// !! this entire datatype must not contain any NULL bytes !! +typedef struct _RobohaxxOverflow_t { + char overflow[MAX_XOR_PAYLOAD_LENGTH]; + uint32_t eip_save; // the address of code to redirect to + uint32_t more_stack[8]; +} RobohaxxOverflow_t; + +#define MAX_EXTRA_PAYLOAD_LENGTH SAVEGAME_DATA_LENGTH - 0x8 - sizeof(RobohaxxOverflow_t) + +// "structure" of the hacked save +typedef struct _RobohaxxSave_t { + uint32_t length; + uint8_t checksum[0x14]; + union { + struct { + uint8_t unk[0x8]; + RobohaxxOverflow_t name; + uint8_t extra_payload[MAX_EXTRA_PAYLOAD_LENGTH]; // max save length + } save; + uint8_t save_bytes[SAVEGAME_DATA_LENGTH]; + }; +} RobohaxxSave_t; + +// static address where the savegame gets loaded straight from the file into +#define EUR_SAVEGAME_ADDRESS 0x0041E20C +#define USA_SAVEGAME_ADDRESS 0xE621E621 // TODO +static uint32_t savegame_address = 0; + +// save file signature keys, generated from HMAC_SHA1(XboxSignatureKey, RobotechXBEKey)[0:16] +#define SIG_KEY_LEN 0x10 +static const uint8_t game_sig_key_EUR[SIG_KEY_LEN] = { 0x82, 0xe1, 0x75, 0x30, 0x4a, 0x3f, 0x85, 0xc1, 0xd1, 0x85, 0xc1, 0x23, 0x25, 0xfb, 0x11, 0x0d }; +static const uint8_t game_sig_key_USA[SIG_KEY_LEN] = { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }; // TODO +static const uint8_t *game_sig_key = NULL; + +static char *output_filename = "game.xsv"; + +static int print_usage(char *filename) { + printf("usage: %s [path to payload] [U/E] [optional output path, default game.xsv] [optional eip overwrite address]\n", filename); + return -1; +} +static int print_error(char *error) { + fprintf(stderr, "error: %s\n", error); + return -1; +} + +static void hexdump(const uint8_t *data, const size_t len) { + for (size_t i = 0; i < len; i++) + printf("%02x", data[i]); +} + +int main(int argc, char **argv) { + printf("robohaxx game.xsv builder by InvoxiPlayGames\n" + "https://github.com/InvoxiPlayGames/robohaxx\n\n"); + if (argc < 3) + return print_usage(argv[0]); + + // make sure the provided region is correct, and set the target address + if (strlen(argv[2]) != 1) + return print_error("argument too long to be a region"); + if (argv[2][0] == 'E' || argv[2][0] == 'e') { + savegame_address = EUR_SAVEGAME_ADDRESS; + game_sig_key = game_sig_key_EUR; + } else if (argv[2][0] == 'U' || argv[2][0] == 'u') { + savegame_address = USA_SAVEGAME_ADDRESS; + game_sig_key = game_sig_key_USA; + } else + return print_error("invalid region provided, must be E or U"); + printf("savegame address: %08x\n", savegame_address); + + // read the payload file and get the filesize + FILE *payload_fp = fopen(argv[1], "rb"); + if (payload_fp == NULL) + return print_error("payload file could not be opened"); + fseek(payload_fp, 0, SEEK_END); + long payload_len = ftell(payload_fp); + fseek(payload_fp, 0, SEEK_SET); + printf("payload length: %li\n", payload_len); + + // we can't have this + if (payload_len > MAX_EXTRA_PAYLOAD_LENGTH || payload_len < 2) + return print_error("payload is too large or short"); + + // allocate a buffer for the payload and read it + uint8_t *payload = malloc(payload_len); + if (payload == NULL) + return print_error("failed to allocate buffer for payload"); + if (fread(payload, 1, payload_len, payload_fp) < payload_len) + return print_error("failed to read entire payload into memory"); + fclose(payload_fp); + + // allocate a buffer for our savegame + RobohaxxSave_t *save = malloc(sizeof(RobohaxxSave_t)); + if (save == NULL) + return print_error("failed to allocate buffer for our savegame"); + // whoops! all zeroes + memset(save, 0, sizeof(RobohaxxSave_t)); + + // fill in the string with nulls + memset(save->save.name.overflow, 'A', sizeof(save->save.name.overflow)); + // set the instruction pointer to our code + // this doesn't actually work - the highest byte (a NULL) gets replaced with 0x0A because of the newline + // so we should really figure out how to make a ROP chain + // the rest of our string is kinda on the stack at the "esp" + save->save.name.eip_save = savegame_address + 0x8 + sizeof(RobohaxxOverflow_t); + if (argc >= 4) save->save.name.eip_save = strtol(argv[4], NULL, 0); + // set the values after this on the stack to our code + for (int i = 0; i < 8; i++) + save->save.name.more_stack[i] = savegame_address + 0x8 + sizeof(RobohaxxOverflow_t); + printf("eip save set to 0x%08x\n", save->save.name.eip_save); + + // straight copy the payload to the extra data in the save + memcpy(save->save.extra_payload, payload, payload_len); + + // set the length + save->length = SAVEGAME_DATA_LENGTH; + // prepare the xbox savegame signature + HMAC_SHA1(game_sig_key, SIG_KEY_LEN, save->save_bytes, save->length, save->checksum); + + printf("generated signature: "); + hexdump(save->checksum, sizeof(save->checksum)); + printf("\n"); + + if (argc >= 4) output_filename = argv[3]; + + printf("writing savegame to %s\n", output_filename); + + FILE *gci_fp = fopen(output_filename, "wb+"); + if (gci_fp == NULL) + return print_error("output file could not be opened"); + if (fwrite(save, sizeof(RobohaxxSave_t), 1, gci_fp) < 1) + return print_error("failed to write to output file"); + fclose(gci_fp); + + printf("successfully written output savegame!\n"); + + // clean up and free everything + free(save); + free(payload); + return 0; +}