github/xrdp
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

security: Check HMAC on non-FIPS slowpath input

Browse Source 
CVE-2026-32105: Add a check that the HMAC signature supplied with a
non-FIPS slowpath input PDU matches the calculated signature.
This commit is contained in:
matt335672
2026-03-10 20:33:15 +00:00
parent 0d8cf57e9d
commit 759104912c
1 changed files with 71 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files
libxrdp/xrdp_sec.c
+71 -33
View File
@@ -861,7 +861,10 @@ xrdp_sec_fips_sign(struct xrdp_sec *self, char *out, int out_len,
}
/*****************************************************************************/
/* Check a FIPS hash is valid */
/* Check a FIPS hash is valid
*
* Result is boolean (i.e. != 0 is OK)
* */
static int
xrdp_sec_fips_check_sig(struct xrdp_sec *self, const char *sig, int sig_len,
char *data, int data_len)
@@ -880,6 +883,66 @@ xrdp_sec_fips_check_sig(struct xrdp_sec *self, const char *sig, int sig_len,
return memcmp(buf, sig, sig_len) == 0;
}
/*****************************************************************************/
/* Generate a MAC hash (5.3.6.1), using a combination of SHA1 and MD5
*
* Salted MAC is not currently supported */
static void
xrdp_sec_sign(struct xrdp_sec *self, char *out, int out_len,
char *data, int data_len)
{
char shasig[20];
char md5sig[16];
char lenhdr[4];
void *sha1_info;
void *md5_info;
buf_out_uint32(lenhdr, data_len);
sha1_info = ssl_sha1_info_create();
md5_info = ssl_md5_info_create();
ssl_sha1_clear(sha1_info);
ssl_sha1_transform(sha1_info, self->sign_key, self->rc4_key_len);
ssl_sha1_transform(sha1_info, (char *)g_pad_54, 40);
ssl_sha1_transform(sha1_info, lenhdr, 4);
ssl_sha1_transform(sha1_info, data, data_len);
ssl_sha1_complete(sha1_info, shasig);
ssl_md5_clear(md5_info);
ssl_md5_transform(md5_info, self->sign_key, self->rc4_key_len);
ssl_md5_transform(md5_info, (char *)g_pad_92, 48);
ssl_md5_transform(md5_info, shasig, 20);
ssl_md5_complete(md5_info, md5sig);
g_memcpy(out, md5sig, out_len);
ssl_sha1_info_delete(sha1_info);
ssl_md5_info_delete(md5_info);
}
/*****************************************************************************/
/* Check a non-FIPS hash is valid
*
* Salted MAC is not currently supported
*
* Result is boolean (i.e. != 0 is OK) */
static int
xrdp_sec_check_sig(struct xrdp_sec *self, const char *sig, int sig_len,
char *data, int data_len)
{
char computed[8];
int rv = 0;
if (sig_len > (int)sizeof(computed))
{
LOG(LOG_LEVEL_ERROR,
"xrdp_sec_check_sig() Buffer overflow (got %d expected %d)",
sig_len, (int)sizeof(computed));
}
else
{
xrdp_sec_sign(self, computed, sig_len, data, data_len);
rv = (memcmp(computed, sig, sig_len) == 0);
}
return rv;
}
/*****************************************************************************/
static void
xrdp_sec_hash_16(char *out, char *in, char *salt1, char *salt2)
@@ -1200,10 +1263,16 @@ xrdp_sec_recv(struct xrdp_sec *self, struct stream *s, int *chan)
return 1;
}
/* TS_SECURITY_HEADER1 */
in_uint8s(s, 8); /* signature(8) */
in_uint8p(s, data_signature, 8);
LOG_DEVEL(LOG_LEVEL_TRACE, "Received header [MS-RDPBCGR] TS_SECURITY_HEADER1 "
"dataSignature (ignored)");
xrdp_sec_decrypt(self, s->p, (int)(s->end - s->p));
if (!xrdp_sec_check_sig(self, data_signature, 8,
s->p, (int)(s->end - s->p)))
{
LOG(LOG_LEVEL_ERROR, "MAC checksum error for non-FIPS PDU");
return 1;
}
}
}
@@ -1274,37 +1343,6 @@ xrdp_sec_recv(struct xrdp_sec *self, struct stream *s, int *chan)
return 0;
}
/*****************************************************************************/
/* Generate a MAC hash (5.2.3.1), using a combination of SHA1 and MD5 */
static void
xrdp_sec_sign(struct xrdp_sec *self, char *out, int out_len,
char *data, int data_len)
{
char shasig[20];
char md5sig[16];
char lenhdr[4];
void *sha1_info;
void *md5_info;
buf_out_uint32(lenhdr, data_len);
sha1_info = ssl_sha1_info_create();
md5_info = ssl_md5_info_create();
ssl_sha1_clear(sha1_info);
ssl_sha1_transform(sha1_info, self->sign_key, self->rc4_key_len);
ssl_sha1_transform(sha1_info, (char *)g_pad_54, 40);
ssl_sha1_transform(sha1_info, lenhdr, 4);
ssl_sha1_transform(sha1_info, data, data_len);
ssl_sha1_complete(sha1_info, shasig);
ssl_md5_clear(md5_info);
ssl_md5_transform(md5_info, self->sign_key, self->rc4_key_len);
ssl_md5_transform(md5_info, (char *)g_pad_92, 48);
ssl_md5_transform(md5_info, shasig, 20);
ssl_md5_complete(md5_info, md5sig);
g_memcpy(out, md5sig, out_len);
ssl_sha1_info_delete(sha1_info);
ssl_md5_info_delete(md5_info);
}
/*****************************************************************************/
/* returns error */
int