Merge pull request #514 from ennorehling/feature/bug-2206-parse_token

parse_token buffer overrun

src/util/parser.c

@@ -192,7 +192,7 @@ char *parse_token(const char **str, char *lbuf, size_t buflen)
             copy = true;
         }
         if (copy) {
-            if (cursor - buflen < lbuf - 1) {
+            if (cursor - buflen < lbuf - len) {
                 memcpy(cursor, ctoken, len);
                 cursor += len;
             }

src/util/parser.test.c

@@ -1,8 +1,58 @@
 #include <platform.h>
 #include "parser.h"
 
+#include <string.h>
 #include <CuTest.h>
 
+static void test_parse_token(CuTest *tc) {
+    char lbuf[8];
+    const char *tok;
+    const char *str, *orig;
+
+    orig = str = "SHORT TOKEN";
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, (void *)(orig+5), (void *)str);
+    CuAssertStrEquals(tc, "SHORT", tok);
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, (void *)(orig + strlen(orig)), (void *)str);
+    CuAssertStrEquals(tc, "TOKEN", tok);
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, NULL, (void *)tok);
+}
+
+static void test_parse_token_limit(CuTest *tc) {
+    char lbuf[8];
+    const char *tok;
+    const char *str, *orig;
+
+    orig = str = "LONG_TOKEN";
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, (void *)(orig + strlen(orig)), (void *)str);
+    CuAssertStrEquals(tc, tok, "LONG_TO");
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, NULL, (void *)tok);
+}
+
+static void test_parse_token_limit_utf8(CuTest *tc) {
+    char lbuf[8];
+    const char *tok;
+    const char *orig = "a\xc3\xa4\xc3\xb6\xc3\xbc\xc3\x9f"; /* auml ouml uuml szlig, 8 bytes long */
+    const char *str = orig+1;
+
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, (void *)(orig + strlen(orig)), (void *)str);
+    CuAssertStrEquals(tc, tok, "\xc3\xa4\xc3\xb6\xc3\xbc"); // just three letters fit, 6 bytes long
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, NULL, (void *)tok);
+
+    str = orig; // now with an extra byte in the front, maxing out lbuf exactly
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, (void *)(orig + strlen(orig)), (void *)str);
+    CuAssertStrEquals(tc, tok, "a\xc3\xa4\xc3\xb6\xc3\xbc");
+    tok = parse_token(&str, lbuf, sizeof(lbuf));
+    CuAssertPtrEquals(tc, NULL, (void *)tok);
+}
+
 static void test_gettoken(CuTest *tc) {
     char token[128];
     init_tokens_str("HELP ONE TWO THREE");
@@ -64,6 +114,9 @@ CuSuite *get_parser_suite(void)
     CuSuite *suite = CuSuiteNew();
     SUITE_ADD_TEST(suite, test_atoip);
     SUITE_ADD_TEST(suite, test_skip_token);
+    SUITE_ADD_TEST(suite, test_parse_token);
+    SUITE_ADD_TEST(suite, test_parse_token_limit);
+    SUITE_ADD_TEST(suite, test_parse_token_limit_utf8);
     SUITE_ADD_TEST(suite, test_gettoken);
     SUITE_ADD_TEST(suite, test_gettoken_short);
     SUITE_ADD_TEST(suite, test_getintegers);