samsungtool: allow firmware creation

The new tool fwcrypt can create a firmware image with a specified
model, version, region and so on.

Change-Id: I0e90e9ab905398a3e7ae3f4fb8b8bbfb2d12d703

utils/samsungtools/Makefile

@@ -3,7 +3,7 @@ CC=gcc
 LD=gcc
 CFLAGS=-g -std=c99 -W -Wall $(DEFINES) `pkg-config --cflags openssl`
 LDFLAGS=`pkg-config --libs openssl`
-BINS=fwdecrypt
+BINS=fwdecrypt fwcrypt
 
 all: $(BINS)
 
@@ -13,5 +13,8 @@ all: $(BINS)
 fwdecrypt: fwdecrypt.o samsung.o
 	$(LD) -o $@ $^ $(LDFLAGS)
 
+fwcrypt: fwcrypt.o samsung.o
+	$(LD) -o $@ $^ $(LDFLAGS)
+
 clean:
 	rm -fr *.o $(BINS)

utils/samsungtools/fwcrypt.c

@@ -0,0 +1,170 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2012 Amaury Pouly
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "samsung.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <getopt.h>
+#include <string.h>
+
+static bool g_debug = false;
+static char *g_out_prefix = NULL;
+
+static void usage(void)
+{
+    printf("Usage: fwcrypt [options] content\n");
+    printf("Options:\n");
+    printf("  -o <prefix>\tSet output file\n");
+    printf("  -m/--model <model>\tSet model\n");
+    printf("  -v/--version <ver>\tSet version\n");
+    printf("  -r/--region <region>\tSet region\n");
+    printf("  -e/--extra <extra>\tSet extra\n");
+    printf("  -?/--help\tDisplay this message\n");
+    printf("  -d/--debug\tDisplay debug messages\n");
+    exit(1);
+}
+
+static int s_write(void *user, int offset, void *buf, int size)
+{
+    FILE *f = user;
+    if(fseek(f, offset, SEEK_SET) != 0)
+        return 0;
+    return fwrite(buf, 1, size, f);
+}
+
+static void s_printf(void *user, bool error, const char *fmt, ...)
+{
+    if(!g_debug && !error)
+        return;
+    (void) user;
+    va_list args;
+    va_start(args, fmt);
+    vprintf(fmt, args);
+    va_end(args);
+}
+
+int main(int argc, char **argv)
+{
+    struct samsung_firmware_t *fw = malloc(sizeof(struct samsung_firmware_t));
+    memset(fw, 0, sizeof(struct samsung_firmware_t));
+    
+    if(argc <= 1)
+        usage();
+
+    while(1)
+    {
+        static struct option long_options[] =
+        {
+            {"help", no_argument, 0, '?'},
+            {"debug", no_argument, 0, 'd'},
+            {"model", required_argument, 0, 'm'},
+            {"version", required_argument, 0, 'v'},
+            {"region", required_argument, 0, 'r'},
+            {"extra", required_argument, 0, 'e'},
+            {0, 0, 0, 0}
+        };
+
+        int c = getopt_long(argc, argv, "?do:m:v:r:e:", long_options, NULL);
+        if(c == -1)
+            break;
+        switch(c)
+        {
+            case -1:
+                break;
+            case 'd':
+                g_debug = true;
+                break;
+            case '?':
+                usage();
+                break;
+            case 'o':
+                g_out_prefix = optarg;
+                break;
+            case 'm':
+                strncpy(fw->model, optarg, sizeof(fw->model));
+                if(strlen(optarg) > sizeof(fw->model))
+                    printf("Warning: truncate model string\n");
+                break;
+            case 'r':
+                strncpy(fw->region, optarg, sizeof(fw->region));
+                if(strlen(optarg) > sizeof(fw->region))
+                    printf("Warning: truncate region string\n");
+                break;
+            case 'v':
+                strncpy(fw->version, optarg, sizeof(fw->version));
+                if(strlen(optarg) > sizeof(fw->version))
+                    printf("Warning: truncate vesion string\n");
+                break;
+            case 'e':
+                strncpy(fw->extra, optarg, sizeof(fw->extra));
+                if(strlen(optarg) > sizeof(fw->extra))
+                    printf("Warning: truncate extra string\n");
+                break;
+            default:
+                abort();
+        }
+    }
+
+    if(optind != argc - 1)
+        usage();
+
+    FILE *fin = fopen(argv[optind], "rb");
+    if(fin == NULL)
+    {
+        printf("Cannot open file for reading: %m\n");
+        samsung_free(fw);
+        return 1;
+    }
+    fseek(fin, 0, SEEK_END);
+    fw->data_size = ftell(fin);
+    fseek(fin, 0, SEEK_SET);
+    fw->data = malloc(fw->data_size);
+    if((int)fread(fw->data, 1, fw->data_size, fin) != fw->data_size)
+    {
+        printf("Cannot read input file: %m\n");
+        samsung_free(fw);
+        return 2;
+    }
+    fclose(fin);
+
+    if(g_out_prefix)
+    {
+        FILE *f = fopen(g_out_prefix, "wb");
+        if(f == NULL)
+        {
+            printf("Cannot open file for writing: %m\n");
+            samsung_free(fw);
+            return 1;
+        }
+
+        enum samsung_error_t err = samsung_write(s_write, s_printf, f, fw);
+        if(err != SAMSUNG_SUCCESS)
+        {
+            printf("Error writing firmware: %d\n", err);
+            samsung_free(fw);
+            return 3;
+        }
+        fclose(f);
+    }
+    samsung_free(fw);
+
+    return 0;
+}

utils/samsungtools/samsung.c

@@ -117,6 +117,57 @@ struct samsung_firmware_t *samsung_read(samsung_read_t read,
     return fw;
 }
 
+enum samsung_error_t samsung_write(samsung_write_t write, samsung_printf_t printf,
+    void *user, struct samsung_firmware_t *fw)
+{
+    struct yp_header_t yp_hdr;
+    struct yp_md5_t yp_md5;
+
+    // write header
+    strncpy(yp_hdr.signature, YP_SIGNATURE, sizeof(yp_hdr.signature));
+    strncpy(yp_hdr.version, fw->version, sizeof(yp_hdr.version));
+    strncpy(yp_hdr.region, fw->region, sizeof(yp_hdr.region));
+    strncpy(yp_hdr.extra, fw->extra, sizeof(yp_hdr.extra));
+    strncpy(yp_hdr.model, fw->model, sizeof(yp_hdr.model));
+    yp_hdr.datasize = fw->data_size;
+
+    printf(user, false, "Model: %s\n", yp_hdr.model);
+    printf(user, false, "Version: %s %s %s\n", yp_hdr.version, yp_hdr.region, yp_hdr.extra);
+
+    if(write(user, 0, &yp_hdr, sizeof(yp_hdr)) != sizeof(yp_hdr))
+    {
+        printf(user, true, "Cannot write header\n");
+        return SAMSUNG_WRITE_ERROR;
+    }
+
+    // encrypt data
+    cyclic_xor(fw->data, fw->data_size, g_yp_key, sizeof(g_yp_key));
+    // compute MD5
+    MD5_CTX c;
+    MD5_Init(&c);
+    MD5_Update(&c, fw->data, fw->data_size);
+    MD5_Final(yp_md5.md5, &c);
+
+    // write data
+    if(write(user, sizeof(yp_hdr), fw->data, fw->data_size) != fw->data_size)
+    {
+        // decrypt data so that the firmware data is the same after the call
+        cyclic_xor(fw->data, fw->data_size, g_yp_key, sizeof(g_yp_key));
+        printf(user, true, "Cannot write data\n");
+        return SAMSUNG_WRITE_ERROR;
+    }
+    // decrypt data so that the firmware data is the same after the call
+    cyclic_xor(fw->data, fw->data_size, g_yp_key, sizeof(g_yp_key));
+    // write md5
+    if(write(user, sizeof(yp_hdr) + fw->data_size, &yp_md5, sizeof(yp_md5)) != sizeof(yp_md5))
+    {
+        printf(user, true, "Cannot write md5\n");
+        return SAMSUNG_WRITE_ERROR;
+    }
+
+    return SAMSUNG_SUCCESS;
+}
+
 void samsung_free(struct samsung_firmware_t *fw)
 {
     if(fw)

utils/samsungtools/samsung.h

@@ -66,13 +66,17 @@ enum samsung_error_t
     SAMSUNG_READ_ERROR = -1,
     SAMSUNG_FORMAT_ERROR = -2,
     SAMSUNG_MD5_ERROR = -3,
+    SAMSUNG_WRITE_ERROR = -4,
 };
 
 typedef int (*samsung_read_t)(void *user, int offset, void *buffer, int size);
+typedef int (*samsung_write_t)(void *user, int offset, void *buffer, int size);
 typedef void (*samsung_printf_t)(void *user, bool error, const char *fmt, ...);
 
 struct samsung_firmware_t *samsung_read(samsung_read_t read,
     samsung_printf_t printf, void *user, enum samsung_error_t *err);
+enum samsung_error_t samsung_write(samsung_write_t write, samsung_printf_t printf,
+    void *user, struct samsung_firmware_t *fw);
 void samsung_free(struct samsung_firmware_t *fw);
 
 #endif /* __SAMSUNG_H__ */