commit 5b9508c9a5d757223c62749c51eaf7453ff26691 Author: Nick Mathewson <nickm@torproject.org> Date: Mon Aug 3 10:11:03 2020 -0400 Add a tor_str_wipe_and_free() function. Frequently we want to do if (s) { memwipe(s, 0, sizeof(s)); tor_free(s); } and it's good to have a way to do this concisely. --- src/lib/crypt_ops/crypto_util.c | 14 ++++++++++++++ src/lib/crypt_ops/crypto_util.h | 10 ++++++++++ 2 files changed, 24 insertions(+) diff --git a/src/lib/crypt_ops/crypto_util.c b/src/lib/crypt_ops/crypto_util.c index 67a1a9eb92..2f821fa024 100644 --- a/src/lib/crypt_ops/crypto_util.c +++ b/src/lib/crypt_ops/crypto_util.c @@ -109,3 +109,17 @@ memwipe(void *mem, uint8_t byte, size_t sz) **/ memset(mem, byte, sz); } + +/** + * Securely all memory in <b>str</b>, then free it. + * + * As tor_free(), tolerates null pointers. + **/ +void +tor_str_wipe_and_free_(char *str) +{ + if (!str) + return; + memwipe(str, 0, strlen(str)); + tor_free_(str); +} diff --git a/src/lib/crypt_ops/crypto_util.h b/src/lib/crypt_ops/crypto_util.h index 613a1bd0dd..b5d7f62521 100644 --- a/src/lib/crypt_ops/crypto_util.h +++ b/src/lib/crypt_ops/crypto_util.h @@ -14,8 +14,18 @@ #define TOR_CRYPTO_UTIL_H #include "lib/cc/torint.h" +#include "lib/malloc/malloc.h" /** OpenSSL-based utility functions. */ void memwipe(void *mem, uint8_t byte, size_t sz); +void tor_str_wipe_and_free_(char *str); +/** + * Securely all memory in <b>str</b>, then free it. + * + * As tor_free(), tolerates null pointers, and sets <b>str</b> to NULL. + **/ +#define tor_str_wipe_and_free(str) \ + FREE_AND_NULL(char, tor_str_wipe_and_free_, (str)) + #endif /* !defined(TOR_CRYPTO_UTIL_H) */