RESPONDER: Ensure that all input strings are valid UTF-8

6 files changed, 49 insertions, 0 deletions

diff --git a/src/external/libunistring.m4 b/src/external/libunistring.m4
index 69c54fe3..18ea3e62 100644
--- a/src/external/libunistring.m4
+++ b/src/external/libunistring.m4
@@ -6,4 +6,9 @@ AC_CHECK_HEADERS(unistr.h,
 AC_CHECK_HEADERS(unicase.h,
     [AC_CHECK_LIB([unistring], [u8_casecmp], [ UNISTRING_LIBS="-lunistring" ], [AC_MSG_ERROR([No usable libunistring library found])])],
     [AC_MSG_ERROR([libunistring header files are not installed])]
+)
+
+AC_CHECK_HEADERS(unistr.h,
+    [AC_CHECK_LIB([unistring], [u8_check], [ UNISTRING_LIBS="-lunistring" ], [AC_MSG_ERROR([No usable libunistring library found])])],
+    [AC_MSG_ERROR([libunistring header files are not installed])]
 )
\ No newline at end of file
diff --git a/src/responder/common/responder.h b/src/responder/common/responder.h
index 321cedda..1b39fdd5 100644
--- a/src/responder/common/responder.h
+++ b/src/responder/common/responder.h
@@ -174,4 +174,6 @@ int sss_dp_send_acct_req(struct resp_ctx *rctx, TALLOC_CTX *callback_memctx,
 int responder_logrotate(DBusMessage *message,
                         struct sbus_connection *conn);
 
+bool sss_utf8_check(const uint8_t *s, size_t n);
+
 #endif /* __SSS_RESPONDER_H__ */
diff --git a/src/responder/common/responder_common.c b/src/responder/common/responder_common.c
index 719f2464..f97ec06f 100644
--- a/src/responder/common/responder_common.c
+++ b/src/responder/common/responder_common.c
@@ -32,6 +32,7 @@
 #include <sys/time.h>
 #include <errno.h>
 #include <popt.h>
+#include <unistr.h>
 #include "util/util.h"
 #include "db/sysdb.h"
 #include "confdb/confdb.h"
@@ -627,3 +628,11 @@ int responder_logrotate(DBusMessage *message,
 
     return monitor_common_pong(message, conn);
 }
+
+bool sss_utf8_check(const uint8_t *s, size_t n)
+{
+    if (u8_check(s, n) == NULL) {
+        return true;
+    }
+    return false;
+}
diff --git a/src/responder/nss/nsssrv_cmd.c b/src/responder/nss/nsssrv_cmd.c
index 8f4cb440..a37bd766 100644
--- a/src/responder/nss/nsssrv_cmd.c
+++ b/src/responder/nss/nsssrv_cmd.c
@@ -873,6 +873,13 @@ static int nss_cmd_getpwnam(struct cli_ctx *cctx)
         ret = EINVAL;
         goto done;
     }
+
+    /* If the body isn't valid UTF-8, fail */
+    if (!sss_utf8_check(body, blen)) {
+        ret = EINVAL;
+        goto done;
+    }
+
     rawname = (const char *)body;
 
     domname = NULL;
@@ -2140,6 +2147,13 @@ static int nss_cmd_getgrnam(struct cli_ctx *cctx)
         ret = EINVAL;
         goto done;
     }
+
+    /* If the body isn't valid UTF-8, fail */
+    if (!sss_utf8_check(body, blen)) {
+        ret = EINVAL;
+        goto done;
+    }
+
     rawname = (const char *)body;
 
     domname = NULL;
@@ -3180,6 +3194,13 @@ static int nss_cmd_initgroups(struct cli_ctx *cctx)
         ret = EINVAL;
         goto done;
     }
+
+    /* If the body isn't valid UTF-8, fail */
+    if (!sss_utf8_check(body, blen)) {
+        ret = EINVAL;
+        goto done;
+    }
+
     rawname = (const char *)body;
 
     domname = NULL;
diff --git a/src/responder/nss/nsssrv_netgroup.c b/src/responder/nss/nsssrv_netgroup.c
index cd0ba723..7d5665d4 100644
--- a/src/responder/nss/nsssrv_netgroup.c
+++ b/src/responder/nss/nsssrv_netgroup.c
@@ -113,6 +113,13 @@ int nss_cmd_setnetgrent(struct cli_ctx *client)
         ret = EINVAL;
         goto done;
     }
+
+    /* If the body isn't valid UTF-8, fail */
+    if (!sss_utf8_check(body, blen)) {
+        ret = EINVAL;
+        goto done;
+    }
+
     rawname = (const char *)body;
 
     req = setnetgrent_send(cmdctx, rawname, cmdctx);
diff --git a/src/responder/pam/pamsrv_cmd.c b/src/responder/pam/pamsrv_cmd.c
index 1d2a2a58..18ba3fdf 100644
--- a/src/responder/pam/pamsrv_cmd.c
+++ b/src/responder/pam/pamsrv_cmd.c
@@ -70,6 +70,11 @@ static int extract_string(char **var, size_t size, uint8_t *body, size_t blen,
 
     if (str[size-1]!='\0') return EINVAL;
 
+    /* If the string isn't valid UTF-8, fail */
+    if (!sss_utf8_check(str, size)) {
+        return EINVAL;
+    }
+
     *c += size;
 
     *var = (char *) str;