!nshlib: Remove fixed login; require FSUTILS_PASSWD

Remove CONFIG_NSH_LOGIN_FIXED and CONFIG_NSH_LOGIN_PASSWORD. Console
and telnet login now depend on CONFIG_FSUTILS_PASSWD and verify
credentials against the passwd file (PBKDF2-HMAC-SHA256).

Signed-off-by: Abhishek Mishra <mishra.abhishek2808@gmail.com>

Author: Abhishekmishra2808

nshlib/Kconfig

@@ -1230,32 +1230,30 @@ config NSH_LOGIN
 config NSH_CONSOLE_LOGIN
 	bool "Console Login"
 	default n
+	depends on FSUTILS_PASSWD
 	select NSH_LOGIN
 	---help---
 		If defined, then the console user will be required to provide a
-		username and password to start the NSH shell.
+		username and password to start the NSH shell.  Requires
+		CONFIG_FSUTILS_PASSWD so credentials are verified against the
+		encrypted password file (for example ROMFS /etc/passwd).
 
 config NSH_TELNET_LOGIN
 	bool "Telnet Login"
 	default n
-	depends on NSH_TELNET
+	depends on NSH_TELNET && FSUTILS_PASSWD
 	select NSH_LOGIN
 	---help---
 		If defined, then the Telnet user will be required to provide a
-		username and password to start the NSH shell.
+		username and password to start the NSH shell.  Requires
+		CONFIG_FSUTILS_PASSWD so credentials are verified against the
+		encrypted password file (for example ROMFS /etc/passwd).
 
 if NSH_LOGIN
 
 choice
 	prompt "Verification method"
-	default NSH_LOGIN_PASSWD if FSUTILS_PASSWD
-	default NSH_LOGIN_FIXED if !FSUTILS_PASSWD
-
-config NSH_LOGIN_FIXED
-	bool "Fixed username/password"
-	---help---
-		Verify user credentials by matching to fixed username and password
-		strings
+	default NSH_LOGIN_PASSWD
 
 config NSH_LOGIN_PLATFORM
 	bool "Platform username/password"
@@ -1292,16 +1290,6 @@ config NSH_LOGIN_USERNAME
 	---help---
 		Login user name.  Default: "root"
 
-config NSH_LOGIN_PASSWORD
-	string "Login password"
-	depends on NSH_LOGIN_FIXED
-	---help---
-		The plaintext login password used when fixed username/password
-		verification is selected (CONFIG_NSH_LOGIN_FIXED).  There is no
-		default; set CONFIG_NSH_LOGIN_PASSWORD in the board defconfig,
-		via menuconfig, or enter it when prompted during an interactive
-		build.
-
 config NSH_LOGIN_FAILDELAY
 	int "Login failure delay"
 	default 0

nshlib/nsh.h

@@ -267,8 +267,6 @@
  * options may be specified:
  *
  * CONFIG_NSH_LOGIN_USERNAME - Login user name.  Default: "root"
- * CONFIG_NSH_LOGIN_PASSWORD - Login password (required when using fixed
- *   credentials; no default is provided).
  * CONFIG_NSH_LOGIN_FAILCOUNT - Number of login retry attempts.
  *   Default 3.
  */

nshlib/nsh_identity.c

@@ -165,9 +165,6 @@ static bool nsh_verify_credentials(FAR const char *username,
   return PASSWORD_VERIFY_MATCH(passwd_verify(username, password));
 #elif defined(CONFIG_NSH_LOGIN_PLATFORM)
   return PASSWORD_VERIFY_MATCH(platform_user_verify(username, password));
-#elif defined(CONFIG_NSH_LOGIN_FIXED)
-  return strcmp(password, CONFIG_NSH_LOGIN_PASSWORD) == 0 &&
-         strcmp(username, CONFIG_NSH_LOGIN_USERNAME) == 0;
 #else
   UNUSED(username);
   UNUSED(password);

nshlib/nsh_login.c

@@ -243,9 +243,6 @@ int nsh_login(FAR struct console_stdio_s *pstate)
 #endif
           if (PASSWORD_VERIFY_MATCH(ret))
 
-#elif defined(CONFIG_NSH_LOGIN_FIXED)
-          if (strcmp(password, CONFIG_NSH_LOGIN_PASSWORD) == 0 &&
-              strcmp(username, CONFIG_NSH_LOGIN_USERNAME) == 0)
 #else
 #  error No user verification method selected
 #endif

nshlib/nsh_telnetlogin.c

@@ -248,9 +248,6 @@ int nsh_telnetlogin(FAR struct console_stdio_s *pstate)
           if (PASSWORD_VERIFY_MATCH(platform_user_verify(username,
                                                          password)))
 #  endif
-#elif defined(CONFIG_NSH_LOGIN_FIXED)
-          if (strcmp(password, CONFIG_NSH_LOGIN_PASSWORD) == 0 &&
-              strcmp(username, CONFIG_NSH_LOGIN_USERNAME) == 0)
 #else
 #  error No user verification method selected
 #endif