1 files changed, 116 insertions, 0 deletions

diff --git a/src/afl-fuzz-queue.c b/src/afl-fuzz-queue.c
index 7afdd9f1..da6b1eee 100644
--- a/src/afl-fuzz-queue.c
+++ b/src/afl-fuzz-queue.c
@@ -24,6 +24,7 @@
 
 #include "afl-fuzz.h"
 #include <limits.h>
+#include <ctype.h>
 
 /* Mark deterministic checks as done for a particular queue entry. We use the
    .state file to avoid repeating deterministic fuzzing when resuming aborted
@@ -100,6 +101,119 @@ void mark_as_redundant(afl_state_t *afl, struct queue_entry *q, u8 state) {
 
 }
 
+/* check if ascii or UTF-8 */
+
+static u8 check_if_text(struct queue_entry *q) {
+
+  if (q->len < AFL_TXT_MIN_LEN) return 0;
+
+  u8  buf[MAX_FILE], bom[3] = {0xef, 0xbb, 0xbf};
+  s32 fd, len = q->len, offset = 0, ascii = 0, utf8 = 0, comp;
+
+  if ((fd = open(q->fname, O_RDONLY)) < 0) return 0;
+  if ((comp = read(fd, buf, len)) != len) return 0;
+  close(fd);
+
+  while (offset < len) {
+
+    // ASCII: <= 0x7F to allow ASCII control characters
+    if ((buf[offset + 0] == 0x09 || buf[offset + 0] == 0x0A ||
+         buf[offset + 0] == 0x0D ||
+         (0x20 <= buf[offset + 0] && buf[offset + 0] <= 0x7E))) {
+
+      offset++;
+      utf8++;
+      ascii++;
+      continue;
+
+    }
+
+    if (isascii((int)buf[offset]) || isprint((int)buf[offset])) {
+
+      ascii++;
+      // we continue though as it can also be a valid utf8
+
+    }
+
+    // non-overlong 2-byte
+    if (((0xC2 <= buf[offset + 0] && buf[offset + 0] <= 0xDF) &&
+         (0x80 <= buf[offset + 1] && buf[offset + 1] <= 0xBF))) {
+
+      offset += 2;
+      utf8++;
+      comp--;
+      continue;
+
+    }
+
+    // excluding overlongs
+    if ((buf[offset + 0] == 0xE0 &&
+         (0xA0 <= buf[offset + 1] && buf[offset + 1] <= 0xBF) &&
+         (0x80 <= buf[offset + 2] &&
+          buf[offset + 2] <= 0xBF)) ||  // straight 3-byte
+        (((0xE1 <= buf[offset + 0] && buf[offset + 0] <= 0xEC) ||
+          buf[offset + 0] == 0xEE || buf[offset + 0] == 0xEF) &&
+         (0x80 <= buf[offset + 1] && buf[offset + 1] <= 0xBF) &&
+         (0x80 <= buf[offset + 2] &&
+          buf[offset + 2] <= 0xBF)) ||  // excluding surrogates
+        (buf[offset + 0] == 0xED &&
+         (0x80 <= buf[offset + 1] && buf[offset + 1] <= 0x9F) &&
+         (0x80 <= buf[offset + 2] && buf[offset + 2] <= 0xBF))) {
+
+      offset += 3;
+      utf8++;
+      comp -= 2;
+      continue;
+
+    }
+
+    // planes 1-3
+    if ((buf[offset + 0] == 0xF0 &&
+         (0x90 <= buf[offset + 1] && buf[offset + 1] <= 0xBF) &&
+         (0x80 <= buf[offset + 2] && buf[offset + 2] <= 0xBF) &&
+         (0x80 <= buf[offset + 3] &&
+          buf[offset + 3] <= 0xBF)) ||  // planes 4-15
+        ((0xF1 <= buf[offset + 0] && buf[offset + 0] <= 0xF3) &&
+         (0x80 <= buf[offset + 1] && buf[offset + 1] <= 0xBF) &&
+         (0x80 <= buf[offset + 2] && buf[offset + 2] <= 0xBF) &&
+         (0x80 <= buf[offset + 3] && buf[offset + 3] <= 0xBF)) ||  // plane 16
+        (buf[offset + 0] == 0xF4 &&
+         (0x80 <= buf[offset + 1] && buf[offset + 1] <= 0x8F) &&
+         (0x80 <= buf[offset + 2] && buf[offset + 2] <= 0xBF) &&
+         (0x80 <= buf[offset + 3] && buf[offset + 3] <= 0xBF))) {
+
+      offset += 4;
+      utf8++;
+      comp -= 3;
+      continue;
+
+    }
+
+    // handle utf8 bom
+    if (buf[offset + 0] == bom[0] && buf[offset + 1] == bom[1] &&
+        buf[offset + 2] == bom[2]) {
+
+      offset += 3;
+      utf8++;
+      comp -= 2;
+      continue;
+
+    }
+
+    offset++;
+
+  }
+
+  u32 percent_utf8 = (utf8 * 100) / comp;
+  u32 percent_ascii = (ascii * 100) / len;
+
+  if (percent_utf8 >= percent_ascii && percent_utf8 >= AFL_TXT_MIN_PERCENT)
+    return 2;
+  if (percent_ascii >= AFL_TXT_MIN_PERCENT) return 1;
+  return 0;
+
+}
+
 /* Append new test case to the queue. */
 
 void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) {
@@ -159,6 +273,8 @@ void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) {
 
   }
 
+  q->is_ascii = check_if_text(q);
+
 }
 
 /* Destroy the entire queue. */