[crc]add crc32 check for loader

loader.c

@@ -1,5 +1,25 @@
 #include <loader.h>
 
+uint32_t rkloader_read_le32(void * addr)
+{
+	uint8_t * p = (uint8_t *)addr;
+
+	return (uint32_t)((p[3] << 24) | (p[2] << 16) | (p[1] << 8) | (p[0] << 0));
+}
+
+char * loader_wide2str(char * str, uint8_t * wide, int len)
+{
+	int i;
+
+	for(i = 0; i < len; i++)
+	{
+		char c = wide[i * 2 + 0] & 0xff;
+		str[i] = (c && isprint(c)) ? c : '\0';
+	}
+	str[i] = '\0';
+	return str;
+}
+
 struct rkloader_ctx_t * rkloader_ctx_alloc(const char * filename)
 {
 	struct rkloader_ctx_t * ctx = calloc(1, sizeof(struct rkloader_ctx_t));
@@ -25,41 +45,52 @@ struct rkloader_ctx_t * rkloader_ctx_alloc(const char * filename)
 			free(ctx);
 		return NULL;
 	}
+
 	ctx->nentry = ctx->header->code471_num + ctx->header->code472_num + ctx->header->loader_num;
+	if(ctx->nentry <= 0)
+	{
+		if(ctx->buffer)
+			free(ctx->buffer);
+		if(ctx)
+			free(ctx);
+		return NULL;
+	}
+
 	for(int i = 0; i < ctx->nentry; i++)
 	{
 		ctx->entry[i] = (struct rkloader_entry_t *)(ctx->buffer + sizeof(struct rkloader_header_t) + sizeof(struct rkloader_entry_t) * i);
 	}
 
-	return ctx;
-}
-
-void rkloader_ctx_free(struct rkloader_ctx_t * ctx)
-{
-	if(ctx)
+	struct rkloader_entry_t * e = ctx->entry[ctx->nentry - 1];
+	uint32_t len = rkloader_read_le32(&e->data_offset) + rkloader_read_le32(&e->data_size);
+	if(ctx->length != len + 4)
 	{
 		if(ctx->buffer)
 			free(ctx->buffer);
-		free(ctx);
+		if(ctx)
+			free(ctx);
+		return NULL;
 	}
-}
 
-uint32_t rkloader_read_le32(void * addr)
-{
-	uint8_t * p = (uint8_t *)addr;
+	uint32_t crc32 = 0x0;
+	if(crc32_sum(crc32, (const uint8_t *)ctx->buffer, len) != rkloader_read_le32((char *)ctx->buffer + len))
+	{
+		if(ctx->buffer)
+			free(ctx->buffer);
+		if(ctx)
+			free(ctx);
+		return NULL;
+	}
 
-	return (uint32_t)((p[3] << 24) | (p[2] << 16) | (p[1] << 8) | (p[0] << 0));
+	return ctx;
 }
 
-char * loader_wide2str(char * str, uint8_t * wide, int len)
+void rkloader_ctx_free(struct rkloader_ctx_t * ctx)
 {
-	int i;
-
-	for(i = 0; i < len; i++)
+	if(ctx)
 	{
-		char c = wide[i * 2 + 0] & 0xff;
-		str[i] = (c && isprint(c)) ? c : '\0';
+		if(ctx->buffer)
+			free(ctx->buffer);
+		free(ctx);
 	}
-	str[i] = '\0';
-	return str;
 }

loader.h

@@ -6,6 +6,7 @@ extern "C" {
 #endif
 
 #include <x.h>
+#include <crc32.h>
 #include <misc.h>
 
 enum rkloader_entry_type_t {
@@ -61,10 +62,10 @@ struct rkloader_ctx_t {
 	int nentry;
 };
 
-struct rkloader_ctx_t * rkloader_ctx_alloc(const char * filename);
-void rkloader_ctx_free(struct rkloader_ctx_t * ctx);
 uint32_t rkloader_read_le32(void * addr);
 char * loader_wide2str(char * str, uint8_t * wide, int len);
+struct rkloader_ctx_t * rkloader_ctx_alloc(const char * filename);
+void rkloader_ctx_free(struct rkloader_ctx_t * ctx);
 
 #ifdef __cplusplus
 }