Add UTF-8 validation to ypc_val_parse()

6 files changed, 68 insertions, 7 deletions

diff --git a/Makefile.am b/Makefile.am
index 2d14a29..9d2e6f3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -27,6 +27,7 @@ libypc_la_SOURCES=\
 	lib/util/str2sockaddr_ip.c\
 	lib/util/str2sockaddr_port.c\
 	lib/util/tweetnacl.c\
+	lib/util/utf8.c\
 	lib/val/ypc_val_parse.c\
 	lib/ypc_init.c\
 	lib/ypc_msg_free.c\
@@ -35,7 +36,8 @@ libypc_la_SOURCES=\
 EXTRA_DIST=\
 	lib/internal.h\
 	lib/util/str2sockaddr.h\
-	lib/util/tweetnacl.h
+	lib/util/tweetnacl.h\
+	lib/util/utf8.h
 
 include_HEADERS=lib/ypc.h
 
diff --git a/lib/util/utf8.c b/lib/util/utf8.c
new file mode 100644
index 0000000..983e9d5
--- /dev/null
+++ b/lib/util/utf8.c
@@ -0,0 +1,23 @@
+/* Copyright (c) 2008-2010 Bjoern Hoehrmann <bjoern@hoehrmann.de>
+ * See http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.
+ *
+ * Also see utf8.h */
+#include <stdint.h>
+
+const uint8_t ypc__utf8d[] = {
+   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+   8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+  10,3,3,3,3,3,3,3,3,3,3,3,3,4,3,3, 11,6,6,6,5,8,8,8,8,8,8,8,8,8,8,8,
+
+   0,12,24,36,60,96,84,12,12,12,48,72, 12,12,12,12,12,12,12,12,12,12,12,12,
+  12, 0,12,12,12,12,12, 0,12, 0,12,12, 12,24,12,12,12,12,12,24,12,24,12,12,
+  12,12,12,12,12,12,12,24,12,12,12,12, 12,24,12,12,12,12,12,12,12,24,12,12,
+  12,12,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,36,12,36,12,12,
+  12,36,12,12,12,12,12,12,12,12,12,12,
+};
+
diff --git a/lib/util/utf8.h b/lib/util/utf8.h
new file mode 100644
index 0000000..b284c14
--- /dev/null
+++ b/lib/util/utf8.h
@@ -0,0 +1,28 @@
+/* Copyright (c) 2008-2010 Bjoern Hoehrmann <bjoern@hoehrmann.de>
+ * See http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.
+ *
+ * Minor modifications for ypc:
+ * - Split into .c/.h files
+ * - Renamed global symbols
+ * - Reduced state to a uint8_t (possibly making things slower, but reducing
+ *   the parsing state of serialized values)
+ */
+
+#include <stdint.h>
+
+#define UTF8_ACCEPT 0
+#define UTF8_REJECT 12
+
+extern const uint8_t ypc__utf8d[];
+
+static inline uint32_t ypc__utf8_decode(uint8_t* state, uint32_t* codep, uint32_t byte) {
+    uint32_t type = ypc__utf8d[byte];
+
+    *codep = (*state != UTF8_ACCEPT) ?
+        (byte & 0x3fu) | (*codep << 6) :
+        (0xff >> type) & (byte);
+
+    *state = ypc__utf8d[256 + *state + type];
+    return *state;
+}
+
diff --git a/lib/val/ypc_val_parse.c b/lib/val/ypc_val_parse.c
index 22124b0..223f776 100644
--- a/lib/val/ypc_val_parse.c
+++ b/lib/val/ypc_val_parse.c
@@ -1,4 +1,5 @@
 #include "../internal.h"
+#include "../util/utf8.h"
 
 typedef enum {
     YPCP_TYPE, /* Expecting a type byte */
@@ -140,9 +141,13 @@ YPC_EXPORT int ypc_val_parse(ypc_val_parser *p, const uint8_t *buf, size_t *lenp
             break;
 
         case YPCP_TEXT:
-            /* TODO: Validate UTF-8 */
-            if(*buf == 0)
-                r = ypc__parse_endval(p);
+            {
+                uint32_t codepoint;
+                if(ypc__utf8_decode(&p->utf8state, &codepoint, *buf) == UTF8_REJECT)
+                    r = -1;
+                else if(*buf == 0)
+                    r = p->utf8state == UTF8_ACCEPT ? ypc__parse_endval(p) : -1;
+            }
             break;
         }
 
@@ -161,5 +166,6 @@ YPC_EXPORT void ypc_val_parse_init(ypc_val_parser *p) {
     p->depth = 0;
     p->wantval = 0;
     p->state = YPCP_TYPE;
+    p->utf8state = UTF8_ACCEPT;
 }
 
diff --git a/lib/ypc.h b/lib/ypc.h
index 310e99e..de2b7be 100644
--- a/lib/ypc.h
+++ b/lib/ypc.h
@@ -46,6 +46,7 @@ typedef struct {
     uint32_t depth : 6;
     uint32_t state : 3;
     bool wantval   : 1;
+    uint8_t utf8state;
     uint32_t pad;
 } ypc_val_parser;
 
diff --git a/test/val_parse.c b/test/val_parse.c
index 9b72e00..a577063 100644
--- a/test/val_parse.c
+++ b/test/val_parse.c
@@ -34,6 +34,7 @@
     } while(0)
 
 int main(int argc, char **argv) {
+    assert(sizeof(ypc_val_parser) == 16);
     /* null */
     T("\0", 1);
     /* false */
@@ -58,9 +59,9 @@ int main(int argc, char **argv) {
     T("\11Hey\0", 1);
     T("\11オリジナルサウンドトラック\0", 1);
     T("\11\xC2\xA2 \xE2\x82\xAC \xF0\xA4\xAD\xA2\0", 1); /* UTF-8 examples from Wikipedia */
-    T("\11\xC2\0", 1); /* XXX: WRONG! */
-    T("\11\xC0\x80\0", 1); /* XXX: WRONG! */
-    T("\11\xF0\x82\xAC\0", 1); /* XXX: WRONG! Overlong (Example from wikipedia) */
+    T("\11\xC2\0", -1);
+    T("\11\xC0\x80\0", -1);
+    T("\11\xF0\x82\xAC\0", -1); /* Overlong (Example from wikipedia) */
     /* Arrays */
     T("\12\0\14", 1);
     T("\12\0\1\11abc\0\14", 1);