Merge upstream-master into master

Commit ecb2c02d994b3e21994f31a70ff911667c262f1f upstream

This nearly (but not quite) corresponds to V_8_3_P1; subsequent
cherry-picks will correct this.

Bug: 162492243
Change-Id: I3c079d86435b7c25aefff4538dc89a3002b1e25b

1 files changed, 52 insertions, 11 deletions

diff --git a/openbsd-compat/xcrypt.c b/openbsd-compat/xcrypt.c
index 8577cbd8..360b187a 100644
--- a/openbsd-compat/xcrypt.c
+++ b/openbsd-compat/xcrypt.c
@@ -25,6 +25,7 @@
 #include "includes.h"
 
 #include <sys/types.h>
+#include <string.h>
 #include <unistd.h>
 #include <pwd.h>
 
@@ -41,7 +42,7 @@
 #  include <sys/security.h>
 #  include <sys/audit.h>
 #  include <prot.h>
-# endif 
+# endif
 
 # if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW)
 #  include <shadow.h>
@@ -62,26 +63,66 @@
 #  define crypt DES_crypt
 # endif
 
+/*
+ * Pick an appropriate password encryption type and salt for the running
+ * system by searching through accounts until we find one that has a valid
+ * salt.  Usually this will be root unless the root account is locked out.
+ * If we don't find one we return a traditional DES-based salt.
+ */
+static const char *
+pick_salt(void)
+{
+	struct passwd *pw;
+	char *passwd, *p;
+	size_t typelen;
+	static char salt[32];
+
+	if (salt[0] != '\0')
+		return salt;
+	strlcpy(salt, "xx", sizeof(salt));
+	setpwent();
+	while ((pw = getpwent()) != NULL) {
+		if ((passwd = shadow_pw(pw)) == NULL)
+			continue;
+		if (passwd[0] == '$' && (p = strrchr(passwd+1, '$')) != NULL) {
+			typelen = p - passwd + 1;
+			strlcpy(salt, passwd, MIN(typelen, sizeof(salt)));
+			explicit_bzero(passwd, strlen(passwd));
+			goto out;
+		}
+	}
+ out:
+	endpwent();
+	return salt;
+}
+
 char *
 xcrypt(const char *password, const char *salt)
 {
 	char *crypted;
 
+	/*
+	 * If we don't have a salt we are encrypting a fake password for
+	 * for timing purposes.  Pick an appropriate salt.
+	 */
+	if (salt == NULL)
+		salt = pick_salt();
+
 # ifdef HAVE_MD5_PASSWORDS
-        if (is_md5_salt(salt))
-                crypted = md5_crypt(password, salt);
-        else
-                crypted = crypt(password, salt);
+	if (is_md5_salt(salt))
+		crypted = md5_crypt(password, salt);
+	else
+		crypted = crypt(password, salt);
 # elif defined(__hpux) && !defined(HAVE_SECUREWARE)
 	if (iscomsec())
-                crypted = bigcrypt(password, salt);
-        else
-                crypted = crypt(password, salt);
+		crypted = bigcrypt(password, salt);
+	else
+		crypted = crypt(password, salt);
 # elif defined(HAVE_SECUREWARE)
-        crypted = bigcrypt(password, salt);
+	crypted = bigcrypt(password, salt);
 # else
-        crypted = crypt(password, salt);
-# endif 
+	crypted = crypt(password, salt);
+# endif
 
 	return crypted;
 }