mokutil/0008-generate_hash-generate_pw_hash-don-t-use-strlen-for-.patch

103 lines
3.1 KiB
Diff

From 385a7dd63fad61a28e38444da797d947f1c79623 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Tue, 15 May 2018 11:20:15 -0400
Subject: [PATCH 01/12] generate_hash() / generate_pw_hash(): don't use
strlen() for strncpy bounds
New gcc rightly comlplains when we do the following:
strncpy (dest, src, strlen(src));
For two reasons:
a) it doesn't copy the NUL byte
b) it's otherwise the same thing strcpy() would have done
This patch replaces that with stpncpy (just because it's slightly easier
to use) and the real bounds for the destination.
Signed-off-by: Peter Jones <pjones@redhat.com>
---
src/mokutil.c | 34 +++++++++++++++++++++++-----------
1 file changed, 23 insertions(+), 11 deletions(-)
diff --git a/src/mokutil.c b/src/mokutil.c
index 6e9a342..6e31e2d 100644
--- a/src/mokutil.c
+++ b/src/mokutil.c
@@ -766,9 +766,10 @@ generate_hash (pw_crypt_t *pw_crypt, char *password, unsigned int pw_len)
{
pw_crypt_t new_crypt;
char settings[SETTINGS_LEN];
+ char *next;
char *crypt_string;
const char *prefix;
- int hash_len, prefix_len;
+ int hash_len, settings_len = sizeof (settings) - 2;
if (!password || !pw_crypt || password[pw_len] != '\0')
return -1;
@@ -776,15 +777,19 @@ generate_hash (pw_crypt_t *pw_crypt, char *password, unsigned int pw_len)
prefix = get_crypt_prefix (pw_crypt->method);
if (!prefix)
return -1;
- prefix_len = strlen(prefix);
pw_crypt->salt_size = get_salt_size (pw_crypt->method);
generate_salt ((char *)pw_crypt->salt, pw_crypt->salt_size);
- strncpy (settings, prefix, prefix_len);
- strncpy (settings + prefix_len, (const char *)pw_crypt->salt,
- pw_crypt->salt_size);
- settings[pw_crypt->salt_size + prefix_len] = '\0';
+ memset (settings, 0, sizeof (settings));
+ next = stpncpy (settings, prefix, settings_len);
+ if (pw_crypt->salt_size > settings_len - (next - settings)) {
+ errno = EOVERFLOW;
+ return -1;
+ }
+ next = stpncpy (next, (const char *)pw_crypt->salt,
+ pw_crypt->salt_size);
+ *next = '\0';
crypt_string = crypt (password, settings);
if (!crypt_string)
@@ -1931,10 +1936,11 @@ static int
generate_pw_hash (const char *input_pw)
{
char settings[SETTINGS_LEN];
+ char *next;
char *password = NULL;
char *crypt_string;
const char *prefix;
- int prefix_len;
+ int settings_len = sizeof (settings) - 2;
unsigned int pw_len, salt_size;
if (input_pw) {
@@ -1960,12 +1966,18 @@ generate_pw_hash (const char *input_pw)
prefix = get_crypt_prefix (DEFAULT_CRYPT_METHOD);
if (!prefix)
return -1;
- prefix_len = strlen(prefix);
- strncpy (settings, prefix, prefix_len);
+ memset (settings, 0, sizeof (settings));
+ next = stpncpy (settings, prefix, settings_len);
salt_size = get_salt_size (DEFAULT_CRYPT_METHOD);
- generate_salt ((settings + prefix_len), salt_size);
- settings[DEFAULT_SALT_SIZE + prefix_len] = '\0';
+ if (salt_size > settings_len - (next - settings)) {
+ free(password);
+ errno = EOVERFLOW;
+ return -1;
+ }
+ generate_salt (next, salt_size);
+ next += salt_size;
+ *next = '\0';
crypt_string = crypt (password, settings);
free (password);
--
2.21.0