Dynamic patch verity and forceencrypt flag

core/jni/core/magiskinit.c

@@ -47,10 +47,15 @@
 #include "cpio.h"
 #include "magisk.h"
 
-// #define VLOG(fmt, ...) printf(fmt, __VA_ARGS__)   /* Enable to debug */
+#ifdef MAGISK_DEBUG
+#define VLOG(fmt, ...) printf(fmt, __VA_ARGS__)
+#else
 #define VLOG(fmt, ...)
+#endif
 
+extern policydb_t *policydb;
 int (*init_applet_main[]) (int, char *[]) = { magiskpolicy_main, magiskpolicy_main, NULL };
+static int keepverity = 0, keepencrypt = 0;
 
 struct cmdline {
 	int skip_initramfs;
@@ -65,8 +70,6 @@ struct device {
 	char path[64];
 };
 
-extern policydb_t *policydb;
-
 static void parse_cmdline(struct cmdline *cmd) {
 	// cleanup
 	cmd->skip_initramfs = 0;
@@ -143,7 +146,24 @@ static int setup_block(struct device *dev, const char *partname) {
 	return 0;
 }
 
-static void patch_ramdisk() {
+static void fstab_patch_cb(int dirfd, struct dirent *entry) {
+	if (entry->d_type == DT_REG && strstr(entry->d_name, "fstab")) {
+		void *buf;
+		size_t _size;
+		uint32_t size;
+		full_read_at(dirfd, entry->d_name, &buf, &_size);
+		size = _size;  /* Type conversion */
+		if (!keepverity)
+			patch_verity(&buf, &size, 1);
+		if (!keepencrypt)
+			patch_encryption(&buf, &size);
+		int fstab = xopenat(dirfd, entry->d_name, O_WRONLY | O_CLOEXEC);
+		write(fstab, buf, size);
+		close(fstab);
+	}
+}
+
+static void patch_ramdisk(int root) {
 	void *addr;
 	size_t size;
 	mmap_rw("/init", &addr, &size);
@@ -161,6 +181,23 @@ static void patch_ramdisk() {
 	write(fd, addr, size);
 	close(fd);
 	free(addr);
+
+	char *key, *value;
+	full_read("/.backup/.magisk", &addr, &size);
+	for (char *tok = strtok(addr, "\n"); tok; tok = strtok(NULL, "\n")) {
+		key = tok;
+		value = strchr(tok, '=') + 1;
+		value[-1] = '\0';
+		if (strcmp(key, "KEEPVERITY") == 0)
+			keepverity = strcmp(value, "true") == 0;
+		else if (strcmp(key, "KEEPFORCEENCRYPT") == 0)
+			keepencrypt = strcmp(value, "true") == 0;
+	}
+
+	excl_list = (char *[]) { "system_root", "system", "vendor", NULL };
+	in_order_walk(root, fstab_patch_cb);
+	if (!keepverity)
+		unlink("/verity_key");
 }
 
 static int strend(const char *s1, const char *s2) {
@@ -456,17 +493,13 @@ int main(int argc, char *argv[]) {
 		}
 	}
 
-	// Only patch initramfs if not intended to run in recovery (legacy devices)
+	int overlay = open("/overlay", O_RDONLY | O_CLOEXEC);
+
+	// Only patch rootfs if not intended to run in recovery
 	if (access("/etc/recovery.fstab", F_OK) != 0) {
-		int overlay = open("/overlay", O_RDONLY | O_CLOEXEC);
 		mv_dir(overlay, root);
 
-		// Clean up
-		rmdir("/overlay");
-		close(overlay);
-		close(root);
-
-		patch_ramdisk();
+		patch_ramdisk(root);
 		patch_sepolicy();
 
 		if (fork_dont_care() == 0) {
@@ -475,7 +508,12 @@ int main(int argc, char *argv[]) {
 		}
 	}
 
+	// Clean up
+	close(overlay);
+	close(root);
 	umount("/vendor");
+	rmdir("/overlay");
+
 	// Finally, give control back!
 	execv("/init", argv);
 }

core/jni/include/cpio.h

@@ -20,7 +20,7 @@ typedef struct cpio_entry {
 	// uint32_t namesize;
 	// uint32_t check;
 	char *filename;
-	char *data;
+	void *data;
 	int remove;
 } cpio_entry;
 

core/jni/include/utils.h

@@ -102,6 +102,7 @@ struct file_attr {
 
 int fd_getpath(int fd, char *path, size_t size);
 int mkdir_p(const char *pathname, mode_t mode);
+void in_order_walk(int dirfd, void (*callback)(int, struct dirent*));
 void rm_rf(const char *path);
 void frm_rf(int dirfd);
 void mv_f(const char *source, const char *destination);
@@ -119,7 +120,9 @@ void clone_attr(const char *source, const char *target);
 void restorecon(int dirfd, int force);
 int mmap_ro(const char *filename, void **buf, size_t *size);
 int mmap_rw(const char *filename, void **buf, size_t *size);
+void fd_full_read(int fd, void **buf, size_t *size);
 void full_read(const char *filename, void **buf, size_t *size);
+void full_read_at(int dirfd, const char *filename, void **buf, size_t *size);
 void stream_full_read(int fd, void **buf, size_t *size);
 void write_zero(int fd, size_t size);
 void mem_align(size_t *pos, size_t align);
@@ -142,7 +145,7 @@ void trim_img(const char *img);
 // pattern.c
 
 void patch_init_rc(void **buf, size_t *size);
-int patch_verity(char **buf, uint32_t *size, int patch);
-void patch_encryption(char **buf, uint32_t *size);
+int patch_verity(void **buf, uint32_t *size, int patch);
+void patch_encryption(void **buf, uint32_t *size);
 
 #endif

core/jni/magiskboot/dtb.c

@@ -78,7 +78,7 @@ static void dtb_patch(const char *file, int patch) {
 				fdt_for_each_subnode(block, fdt, fstab) {
 					fprintf(stderr, "Found block [%s] in fstab\n", fdt_get_name(fdt, block, NULL));
 					uint32_t value_size;
-					char *value = (char *) fdt_getprop(fdt, block, "fsmgr_flags", &value_size);
+					void *value = (char *) fdt_getprop(fdt, block, "fsmgr_flags", &value_size);
 					found |= patch_verity(&value, &value_size, patch);
 				}
 			}

core/jni/magiskboot/ramdisk.c

@@ -58,7 +58,7 @@ static char *cpio_stocksha1(struct vector *v) {
 	vec_for_each(v, f) {
 		if (strcmp(f->filename, "init.magisk.rc") == 0
 			|| strcmp(f->filename, "overlay/init.magisk.rc") == 0) {
-			for (char *pos = f->data; pos < f->data + f->filesize; pos = strchr(pos + 1, '\n') + 1) {
+			for (void *pos = f->data; pos < f->data + f->filesize; pos = strchr(pos + 1, '\n') + 1) {
 				if (memcmp(pos, "# STOCKSHA1=", 12) == 0) {
 					pos += 12;
 					memcpy(sha1, pos, 40);

core/jni/utils/file.c

@@ -17,13 +17,13 @@
 
 #include "utils.h"
 
-char **excl_list = (char *[]) { NULL };
+char **excl_list = NULL;
 
 static int is_excl(const char *name) {
-	for (int i = 0; excl_list[i]; ++i) {
-		if (strcmp(name, excl_list[i]) == 0)
-			return 1;
-	}
+	if (excl_list)
+		for (int i = 0; excl_list[i]; ++i)
+			if (strcmp(name, excl_list[i]) == 0)
+				return 1;
 	return 0;
 }
 
@@ -55,6 +55,36 @@ int mkdir_p(const char *pathname, mode_t mode) {
 	return 0;
 }
 
+void in_order_walk(int dirfd, void (*callback)(int, struct dirent*)) {
+	struct dirent *entry;
+	int newfd;
+	DIR *dir = xfdopendir(dirfd);
+
+	while ((entry = xreaddir(dir))) {
+		if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
+			continue;
+		if (is_excl(entry->d_name))
+			continue;
+		if (entry->d_type == DT_DIR) {
+			newfd = xopenat(dirfd, entry->d_name, O_RDONLY | O_CLOEXEC);
+			in_order_walk(newfd, callback);
+			close(newfd);
+		}
+		callback(dirfd, entry);
+	}
+}
+
+static void rm_cb(int dirfd, struct dirent *entry) {
+	switch (entry->d_type) {
+	case DT_DIR:
+		unlinkat(dirfd, entry->d_name, AT_REMOVEDIR);
+		break;
+	default:
+		unlinkat(dirfd, entry->d_name, 0);
+		break;
+	}
+}
+
 void rm_rf(const char *path) {
 	int fd = xopen(path, O_RDONLY | O_CLOEXEC);
 	if (fd < 0)
@@ -65,27 +95,7 @@ void rm_rf(const char *path) {
 }
 
 void frm_rf(int dirfd) {
-	struct dirent *entry;
-	int newfd;
-	DIR *dir = xfdopendir(dirfd);
-
-	while ((entry = xreaddir(dir))) {
-		if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
-			continue;
-		if (is_excl(entry->d_name))
-			continue;
-		switch (entry->d_type) {
-		case DT_DIR:
-			newfd = xopenat(dirfd, entry->d_name, O_RDONLY | O_CLOEXEC);
-			frm_rf(newfd);
-			close(newfd);
-			unlinkat(dirfd, entry->d_name, AT_REMOVEDIR);
-			break;
-		default:
-			unlinkat(dirfd, entry->d_name, 0);
-			break;
-		}
-	}
+	in_order_walk(dirfd, rm_cb);
 }
 
 /* This will only on the same file system */
@@ -360,6 +370,13 @@ int mmap_rw(const char *filename, void **buf, size_t *size) {
 	return _mmap(1, filename, buf, size);
 }
 
+void fd_full_read(int fd, void **buf, size_t *size) {
+	*size = lseek(fd, 0, SEEK_END);
+	lseek(fd, 0, SEEK_SET);
+	*buf = xmalloc(*size);
+	xxread(fd, *buf, *size);
+}
+
 void full_read(const char *filename, void **buf, size_t *size) {
 	int fd = xopen(filename, O_RDONLY);
 	if (fd < 0) {
@@ -367,10 +384,18 @@ void full_read(const char *filename, void **buf, size_t *size) {
 		*size = 0;
 		return;
 	}
-	*size = lseek(fd, 0, SEEK_END);
-	lseek(fd, 0, SEEK_SET);
-	*buf = xmalloc(*size);
-	xxread(fd, *buf, *size);
+	fd_full_read(fd, buf, size);
+	close(fd);
+}
+
+void full_read_at(int dirfd, const char *filename, void **buf, size_t *size) {
+	int fd = xopenat(dirfd, filename, O_RDONLY);
+	if (fd < 0) {
+		*buf = NULL;
+		*size = 0;
+		return;
+	}
+	fd_full_read(fd, buf, size);
 	close(fd);
 }
 

core/jni/utils/pattern.c

@@ -58,12 +58,12 @@ void patch_init_rc(void **buf, size_t *size) {
 	*buf = new_data;
 }
 
-int patch_verity(char **buf, uint32_t *size, int patch) {
+int patch_verity(void **buf, uint32_t *size, int patch) {
 	int skip, found = 0;
 	for (int pos = 0; pos < *size; ++pos) {
 		if ((skip = check_verity_pattern(*buf + pos)) > 0) {
 			found = 1;
-			fprintf(stderr, "%s pattern [%.*s]\n", patch ? "Remove" : "Found", skip, *buf + pos);
+			fprintf(stderr, "%s pattern [%.*s]\n", patch ? "Remove" : "Found", skip, (char *) *buf + pos);
 			if (patch) {
 				memcpy(*buf + pos, *buf + pos + skip, *size - pos - skip);
 				memset(*buf + *size - skip, '\0', skip);
@@ -76,11 +76,11 @@ int patch_verity(char **buf, uint32_t *size, int patch) {
 	return found;
 }
 
-void patch_encryption(char **buf, uint32_t *size) {
+void patch_encryption(void **buf, uint32_t *size) {
 	int skip;
 	for (int pos = 0; pos < *size; ++pos) {
 		if ((skip = check_encryption_pattern(*buf + pos)) > 0) {
-			fprintf(stderr, "Replace pattern [%.*s] with [encryptable]\n", skip, *buf + pos);
+			fprintf(stderr, "Replace pattern [%.*s] with [encryptable]\n", skip, (char *) *buf + pos);
 			memcpy(*buf + pos, "encryptable", 11);
 			memcpy(*buf + pos + 11, *buf + pos + skip, *size - pos - skip);
 			memset(*buf + *size - skip + 11, '\0', skip - 11);

scripts/boot_patch.sh

@@ -64,7 +64,7 @@ BOOTIMAGE="$1"
 # Presets
 [ -z $KEEPVERITY ] && KEEPVERITY=false
 [ -z $KEEPFORCEENCRYPT ] && KEEPFORCEENCRYPT=false
-[ -z $HIGH_COMP ] && HIGH_COMP=false
+[ -z $HIGHCOMP ] && HIGHCOMP=false
 
 chmod -R 755 .
 
@@ -89,7 +89,7 @@ case $? in
   2 )
     ui_print "! Insufficient boot partition size detected"
     ui_print "- Enable high compression mode"
-    HIGH_COMP=true
+    HIGHCOMP=true
     ;;
   3 )
     ui_print "- ChromeOS boot image detected"
@@ -139,11 +139,10 @@ esac
 
 ui_print "- Patching ramdisk"
 
-[ -f /sdcard/ramdisk-recovery.img ] && HIGH_COMP=true
+[ -f /sdcard/ramdisk-recovery.img ] && HIGHCOMP=true
 
-./magiskboot --cpio-patch ramdisk.cpio $KEEPVERITY $KEEPFORCEENCRYPT
 ./magiskboot --cpio-add ramdisk.cpio 750 init magiskinit
-./magiskboot --cpio-backup ramdisk.cpio ramdisk.cpio.orig $HIGH_COMP $SHA1
+./magiskboot --cpio-backup ramdisk.cpio ramdisk.cpio.orig $HIGHCOMP $KEEPVERITY $KEEPFORCEENCRYPT $SHA1
 
 rm -f ramdisk.cpio.orig