diff options
| -rw-r--r-- | src/sss_client/common.c | 29 | ||||
| -rw-r--r-- | src/sss_client/sss_cli.h | 5 |
2 files changed, 34 insertions, 0 deletions
diff --git a/src/sss_client/common.c b/src/sss_client/common.c index 6b79c7830..3bfa89281 100644 --- a/src/sss_client/common.c +++ b/src/sss_client/common.c @@ -761,3 +761,32 @@ const char *ssscli_err2string(int err) return _("Unexpected error while looking for an error description"); } + +/* Return strlen(str) or maxlen, whichever is shorter + * Returns EINVAL if str is NULL, EFBIG if str is longer than maxlen + * _len will return the result + * + * This function is useful for preventing buffer overflow attacks. + */ +errno_t sss_strnlen(const char *str, size_t maxlen, size_t *len) +{ + if (!str) { + return EINVAL; + } + +#if defined __USE_GNU + *len = strnlen(str, maxlen); +#else + *len = 0; + while (*len < maxlen) { + if (str[*len] == '\0') break; + len++; + } +#endif + + if (*len == maxlen && str[*len] != '\0') { + return EFBIG; + } + + return 0; +} diff --git a/src/sss_client/sss_cli.h b/src/sss_client/sss_cli.h index 8712a6f90..e0a33df46 100644 --- a/src/sss_client/sss_cli.h +++ b/src/sss_client/sss_cli.h @@ -470,3 +470,8 @@ safealign_memcpy(void *dest, const void *src, size_t n, size_t *counter) */ #endif +/* Return strlen(str) or maxlen, whichever is shorter + * Returns EINVAL if str is NULL, EFBIG if str is longer than maxlen + * _len will return the result + */ +errno_t sss_strnlen(const char *str, size_t maxlen, size_t *len); |