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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <ctype.h>
     18 #include <errno.h>
     19 #include <fcntl.h>
     20 #include <limits.h>
     21 #include <sys/stat.h>
     22 #include <sys/wait.h>
     23 #include <unistd.h>
     24 
     25 #include "common.h"
     26 #include "install.h"
     27 #include "mincrypt/rsa.h"
     28 #include "minui/minui.h"
     29 #include "minzip/SysUtil.h"
     30 #include "minzip/Zip.h"
     31 #include "mtdutils/mounts.h"
     32 #include "mtdutils/mtdutils.h"
     33 #include "roots.h"
     34 #include "verifier.h"
     35 
     36 #define ASSUMED_UPDATE_BINARY_NAME  "META-INF/com/google/android/update-binary"
     37 #define PUBLIC_KEYS_FILE "/res/keys"
     38 
     39 // If the package contains an update binary, extract it and run it.
     40 static int
     41 try_update_binary(const char *path, ZipArchive *zip, int* wipe_cache) {
     42     const ZipEntry* binary_entry =
     43             mzFindZipEntry(zip, ASSUMED_UPDATE_BINARY_NAME);
     44     if (binary_entry == NULL) {
     45         mzCloseZipArchive(zip);
     46         return INSTALL_CORRUPT;
     47     }
     48 
     49     char* binary = "/tmp/update_binary";
     50     unlink(binary);
     51     int fd = creat(binary, 0755);
     52     if (fd < 0) {
     53         mzCloseZipArchive(zip);
     54         LOGE("Can't make %s\n", binary);
     55         return INSTALL_ERROR;
     56     }
     57     bool ok = mzExtractZipEntryToFile(zip, binary_entry, fd);
     58     close(fd);
     59     mzCloseZipArchive(zip);
     60 
     61     if (!ok) {
     62         LOGE("Can't copy %s\n", ASSUMED_UPDATE_BINARY_NAME);
     63         return INSTALL_ERROR;
     64     }
     65 
     66     int pipefd[2];
     67     pipe(pipefd);
     68 
     69     // When executing the update binary contained in the package, the
     70     // arguments passed are:
     71     //
     72     //   - the version number for this interface
     73     //
     74     //   - an fd to which the program can write in order to update the
     75     //     progress bar.  The program can write single-line commands:
     76     //
     77     //        progress <frac> <secs>
     78     //            fill up the next <frac> part of of the progress bar
     79     //            over <secs> seconds.  If <secs> is zero, use
     80     //            set_progress commands to manually control the
     81     //            progress of this segment of the bar
     82     //
     83     //        set_progress <frac>
     84     //            <frac> should be between 0.0 and 1.0; sets the
     85     //            progress bar within the segment defined by the most
     86     //            recent progress command.
     87     //
     88     //        firmware <"hboot"|"radio"> <filename>
     89     //            arrange to install the contents of <filename> in the
     90     //            given partition on reboot.
     91     //
     92     //            (API v2: <filename> may start with "PACKAGE:" to
     93     //            indicate taking a file from the OTA package.)
     94     //
     95     //            (API v3: this command no longer exists.)
     96     //
     97     //        ui_print <string>
     98     //            display <string> on the screen.
     99     //
    100     //   - the name of the package zip file.
    101     //
    102 
    103     char** args = malloc(sizeof(char*) * 5);
    104     args[0] = binary;
    105     args[1] = EXPAND(RECOVERY_API_VERSION);   // defined in Android.mk
    106     args[2] = malloc(10);
    107     sprintf(args[2], "%d", pipefd[1]);
    108     args[3] = (char*)path;
    109     args[4] = NULL;
    110 
    111     pid_t pid = fork();
    112     if (pid == 0) {
    113         close(pipefd[0]);
    114         execv(binary, args);
    115         fprintf(stdout, "E:Can't run %s (%s)\n", binary, strerror(errno));
    116         _exit(-1);
    117     }
    118     close(pipefd[1]);
    119 
    120     *wipe_cache = 0;
    121 
    122     char buffer[1024];
    123     FILE* from_child = fdopen(pipefd[0], "r");
    124     while (fgets(buffer, sizeof(buffer), from_child) != NULL) {
    125         char* command = strtok(buffer, " \n");
    126         if (command == NULL) {
    127             continue;
    128         } else if (strcmp(command, "progress") == 0) {
    129             char* fraction_s = strtok(NULL, " \n");
    130             char* seconds_s = strtok(NULL, " \n");
    131 
    132             float fraction = strtof(fraction_s, NULL);
    133             int seconds = strtol(seconds_s, NULL, 10);
    134 
    135             ui_show_progress(fraction * (1-VERIFICATION_PROGRESS_FRACTION),
    136                              seconds);
    137         } else if (strcmp(command, "set_progress") == 0) {
    138             char* fraction_s = strtok(NULL, " \n");
    139             float fraction = strtof(fraction_s, NULL);
    140             ui_set_progress(fraction);
    141         } else if (strcmp(command, "ui_print") == 0) {
    142             char* str = strtok(NULL, "\n");
    143             if (str) {
    144                 ui_print("%s", str);
    145             } else {
    146                 ui_print("\n");
    147             }
    148         } else if (strcmp(command, "wipe_cache") == 0) {
    149             *wipe_cache = 1;
    150         } else {
    151             LOGE("unknown command [%s]\n", command);
    152         }
    153     }
    154     fclose(from_child);
    155 
    156     int status;
    157     waitpid(pid, &status, 0);
    158     if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
    159         LOGE("Error in %s\n(Status %d)\n", path, WEXITSTATUS(status));
    160         return INSTALL_ERROR;
    161     }
    162 
    163     return INSTALL_SUCCESS;
    164 }
    165 
    166 // Reads a file containing one or more public keys as produced by
    167 // DumpPublicKey:  this is an RSAPublicKey struct as it would appear
    168 // as a C source literal, eg:
    169 //
    170 //  "{64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}"
    171 //
    172 // (Note that the braces and commas in this example are actual
    173 // characters the parser expects to find in the file; the ellipses
    174 // indicate more numbers omitted from this example.)
    175 //
    176 // The file may contain multiple keys in this format, separated by
    177 // commas.  The last key must not be followed by a comma.
    178 //
    179 // Returns NULL if the file failed to parse, or if it contain zero keys.
    180 static RSAPublicKey*
    181 load_keys(const char* filename, int* numKeys) {
    182     RSAPublicKey* out = NULL;
    183     *numKeys = 0;
    184 
    185     FILE* f = fopen(filename, "r");
    186     if (f == NULL) {
    187         LOGE("opening %s: %s\n", filename, strerror(errno));
    188         goto exit;
    189     }
    190 
    191     int i;
    192     bool done = false;
    193     while (!done) {
    194         ++*numKeys;
    195         out = realloc(out, *numKeys * sizeof(RSAPublicKey));
    196         RSAPublicKey* key = out + (*numKeys - 1);
    197         if (fscanf(f, " { %i , 0x%x , { %u",
    198                    &(key->len), &(key->n0inv), &(key->n[0])) != 3) {
    199             goto exit;
    200         }
    201         if (key->len != RSANUMWORDS) {
    202             LOGE("key length (%d) does not match expected size\n", key->len);
    203             goto exit;
    204         }
    205         for (i = 1; i < key->len; ++i) {
    206             if (fscanf(f, " , %u", &(key->n[i])) != 1) goto exit;
    207         }
    208         if (fscanf(f, " } , { %u", &(key->rr[0])) != 1) goto exit;
    209         for (i = 1; i < key->len; ++i) {
    210             if (fscanf(f, " , %u", &(key->rr[i])) != 1) goto exit;
    211         }
    212         fscanf(f, " } } ");
    213 
    214         // if the line ends in a comma, this file has more keys.
    215         switch (fgetc(f)) {
    216             case ',':
    217                 // more keys to come.
    218                 break;
    219 
    220             case EOF:
    221                 done = true;
    222                 break;
    223 
    224             default:
    225                 LOGE("unexpected character between keys\n");
    226                 goto exit;
    227         }
    228     }
    229 
    230     fclose(f);
    231     return out;
    232 
    233 exit:
    234     if (f) fclose(f);
    235     free(out);
    236     *numKeys = 0;
    237     return NULL;
    238 }
    239 
    240 static int
    241 really_install_package(const char *path, int* wipe_cache)
    242 {
    243     ui_set_background(BACKGROUND_ICON_INSTALLING);
    244     ui_print("Finding update package...\n");
    245     ui_show_indeterminate_progress();
    246     LOGI("Update location: %s\n", path);
    247 
    248     if (ensure_path_mounted(path) != 0) {
    249         LOGE("Can't mount %s\n", path);
    250         return INSTALL_CORRUPT;
    251     }
    252 
    253     ui_print("Opening update package...\n");
    254 
    255     int numKeys;
    256     RSAPublicKey* loadedKeys = load_keys(PUBLIC_KEYS_FILE, &numKeys);
    257     if (loadedKeys == NULL) {
    258         LOGE("Failed to load keys\n");
    259         return INSTALL_CORRUPT;
    260     }
    261     LOGI("%d key(s) loaded from %s\n", numKeys, PUBLIC_KEYS_FILE);
    262 
    263     // Give verification half the progress bar...
    264     ui_print("Verifying update package...\n");
    265     ui_show_progress(
    266             VERIFICATION_PROGRESS_FRACTION,
    267             VERIFICATION_PROGRESS_TIME);
    268 
    269     int err;
    270     err = verify_file(path, loadedKeys, numKeys);
    271     free(loadedKeys);
    272     LOGI("verify_file returned %d\n", err);
    273     if (err != VERIFY_SUCCESS) {
    274         LOGE("signature verification failed\n");
    275         return INSTALL_CORRUPT;
    276     }
    277 
    278     /* Try to open the package.
    279      */
    280     ZipArchive zip;
    281     err = mzOpenZipArchive(path, &zip);
    282     if (err != 0) {
    283         LOGE("Can't open %s\n(%s)\n", path, err != -1 ? strerror(err) : "bad");
    284         return INSTALL_CORRUPT;
    285     }
    286 
    287     /* Verify and install the contents of the package.
    288      */
    289     ui_print("Installing update...\n");
    290     return try_update_binary(path, &zip, wipe_cache);
    291 }
    292 
    293 int
    294 install_package(const char* path, int* wipe_cache, const char* install_file)
    295 {
    296     FILE* install_log = fopen_path(install_file, "w");
    297     if (install_log) {
    298         fputs(path, install_log);
    299         fputc('\n', install_log);
    300     } else {
    301         LOGE("failed to open last_install: %s\n", strerror(errno));
    302     }
    303     int result = really_install_package(path, wipe_cache);
    304     if (install_log) {
    305         fputc(result == INSTALL_SUCCESS ? '1' : '0', install_log);
    306         fputc('\n', install_log);
    307         fclose(install_log);
    308     }
    309     return result;
    310 }
    311