Migrate MagiskBoot to C++

native/jni/magiskboot/pattern.cpp

@@ -0,0 +1,74 @@
+#include <malloc.h>
+#include <string.h>
+
+#include "magiskboot.h"
+#include "utils.h"
+
+static int check_verity_pattern(const char *s) {
+	int skip = 0;
+	if (s[0] == ',') ++skip;
+	if (strncmp(s + skip, "verify", 6) == 0)
+		skip += 6;
+	else if (strncmp(s + skip, "avb", 3) == 0)
+		skip += 3;
+	else
+		return -1;
+
+	if (s[skip] == '=') {
+		while (s[skip] != '\0' && s[skip] != ' ' && s[skip] != '\n' && s[skip] != ',') ++skip;
+	}
+	return skip;
+}
+
+static int check_encryption_pattern(const char *s) {
+	const char *encrypt_list[] = { "forceencrypt", "forcefdeorfbe", NULL };
+	for (int i = 0 ; encrypt_list[i]; ++i) {
+		int len = strlen(encrypt_list[i]);
+		if (strncmp(s, encrypt_list[i], len) == 0)
+			return len;
+	}
+	return -1;
+}
+
+int patch_verity(void **buf, uint32_t *size, int patch) {
+	int skip, src_size = *size, found = 0;
+	char *src = (char *) *buf, *patched = patch ? (char *) xcalloc(src_size, 1) : nullptr;
+	for (int read = 0, write = 0; read < src_size; ++read, ++write) {
+		if ((skip = check_verity_pattern(src + read)) > 0) {
+			if (patch) {
+				fprintf(stderr, "Remove pattern [%.*s]\n", skip, src + read);
+				*size -= skip;
+			} else {
+				fprintf(stderr, "Found pattern [%.*s]\n", skip, src + read);
+			}
+			read += skip;
+			found = 1;
+		}
+		if (patch)
+			patched[write] = src[read];
+	}
+	if (patch) {
+		free(*buf);
+		*buf = patched;
+	}
+	return found;
+}
+
+void patch_encryption(void **buf, uint32_t *size) {
+	int skip, src_size = *size;
+	char *src = (char *) *buf, *patched = (char *) xcalloc(src_size, 1);
+	for (int read = 0, write = 0; read < src_size; ++read, ++write) {
+		if ((skip = check_encryption_pattern(src + read)) > 0) {
+			fprintf(stderr, "Replace pattern [%.*s] with [encryptable]\n", skip, src + read);
+			memcpy(patched + read, "encryptable", 11);
+			read += skip;
+			write += 11;
+			*size -= (skip - 11);
+		}
+		patched[write] = src[read];
+	}
+	free(*buf);
+	*buf = patched;
+}
+
+