idevicebackup: read and verify manifest.plist when restoring

1 files changed, 70 insertions, 0 deletions

diff --git a/tools/idevicebackup.c b/tools/idevicebackup.c
index 2018bc6..15b8d05 100644
--- a/tools/idevicebackup.c
+++ b/tools/idevicebackup.c
@@ -26,6 +26,7 @@
 #include <stdlib.h>
 #include <signal.h>
 #include <glib.h>
+#include <gcrypt.h>
 
 #include <libimobiledevice/libimobiledevice.h>
 #include <libimobiledevice/lockdown.h>
@@ -59,6 +60,23 @@ enum device_link_file_status_t {
         DEVICE_LINK_FILE_STATUS_LAST_HUNK
 };
 
+static void sha1_of_data(const char *input, uint32_t size, unsigned char *hash_out)
+{
+        gcry_md_hash_buffer(GCRY_MD_SHA1, hash_out, input, size);
+}
+
+static int compare_hash(const unsigned char *hash1, const unsigned char *hash2, int hash_len)
+{
+        int i;
+        for (i = 0; i < hash_len; i++) {
+                if (hash1[i] != hash2[i]) {
+                        return 0;
+                }
+        }
+        return 1;
+}
+
+
 static void notify_cb(const char *notification, void *userdata)
 {
         if (!strcmp(notification, NP_SYNC_CANCEL_REQUEST)) {
@@ -913,6 +931,58 @@ int main(int argc, char *argv[])
                                 break;
                         }
                         /* now make sure backup integrity is ok! verify all files */
+                        printf("Reading existing Manifest.\n");
+                        plist_read_from_filename(&manifest_plist, manifest_path);
+                        if (!manifest_plist) {
+                                printf("Could not read Manifest.plist. Aborting.\n");
+                                break;
+                        }
+
+                        printf("Verifying backup integrity, please wait.\n");
+                        char *bin = NULL;
+                        uint64_t binsize = 0;
+                        node = plist_dict_get_item(manifest_plist, "Data");
+                        if (!node || (plist_get_node_type(node) != PLIST_DATA)) {
+                                printf("Could not read Data key from Manifest.plist!\n");
+                                break;
+                        }
+                        plist_get_data_val(node, &bin, &binsize);
+                        plist_t backup_data = NULL;
+                        if (bin) {
+                                char *auth_ver = NULL;
+                                unsigned char *auth_sig = NULL;
+                                uint64_t auth_sig_len = 0;
+                                /* verify AuthSignature */
+                                node = plist_dict_get_item(manifest_plist, "AuthVersion");
+                                plist_get_string_val(node, &auth_ver);
+                                if (auth_ver && (strcmp(auth_ver, "2.0") == 0)) {
+                                        node = plist_dict_get_item(manifest_plist, "AuthSignature");
+                                        if (node && (plist_get_node_type(node) == PLIST_DATA)) {
+                                                plist_get_data_val(node, (char**)&auth_sig, &auth_sig_len);
+                                        }
+                                        if (auth_sig && (auth_sig_len == 20)) {
+                                                /* calculate the sha1, then compare */
+                                                unsigned char data_sha1[20];
+                                                sha1_of_data(bin, binsize, data_sha1);
+                                                if (compare_hash(auth_sig, data_sha1, 20)) {
+                                                        printf("AuthSignature is valid\n");
+                                                } else {
+                                                        printf("ERROR: AuthSignature is NOT VALID\n");
+                                                }
+                                        } else {
+                                                printf("Could not get AuthSignature from manifest!\n");
+                                        }
+                                        g_free(auth_sig);
+                                } else if (auth_ver) {
+                                        printf("Unknown AuthVersion '%s', cannot verify AuthSignature\n", auth_ver); 
+                                }
+                                plist_from_bin(bin, (uint32_t)binsize, &backup_data);
+                                g_free(bin);
+                        }
+                        if (!backup_data) {
+                                printf("Could not read plist from Manifest.plist Data key!\n");
+                                break;
+                        }
                                 /* loop over Files entries in Manifest data plist */
                                         /* make sure both .mddata/.mdinfo files are available for each entry */
                         /* request restore from device with manifest (BackupMessageRestoreMigrate) */