ima: add Kconfig default measurement list template

This patch adds a Kconfig option to select the default IMA
measurement list template. The 'ima' template limited the
filedata hash to 20 bytes and the pathname to 255 charaters.
The 'ima-ng' measurement list template permits larger hash
digests and longer pathnames.

Changelog:
- keep 'select CRYPTO_HASH_INFO' in 'config IMA' section (Kconfig)
(Roberto Sassu);
- removed trailing whitespaces (Roberto Sassu).
- Lindent fixes

Signed-off-by: Mimi Zohar <[e-mail]>
Signed-off-by: Roberto Sassu <[e-mail]>

security/integrity/ima/Kconfig

···
 	help
 	  Disabling this option will disregard LSM based policy rules.
 
+choice
+	prompt "Default template"
+	default IMA_NG_TEMPLATE
+	depends on IMA
+	help
+	  Select the default IMA measurement template.
+
+	  The original 'ima' measurement list template contains a
+	  hash, defined as 20 bytes, and a null terminated pathname,
+	  limited to 255 characters.  The 'ima-ng' measurement list
+	  template permits both larger hash digests and longer
+	  pathnames.
+
+	config IMA_TEMPLATE
+		bool "ima"
+	config IMA_NG_TEMPLATE
+		bool "ima-ng (default)"
+endchoice
+
+config IMA_DEFAULT_TEMPLATE
+	string
+	depends on IMA
+	default "ima" if IMA_TEMPLATE
+	default "ima-ng" if IMA_NG_TEMPLATE
+
 config IMA_APPRAISE
 	bool "Appraise integrity measurements"
 	depends on IMA

security/integrity/ima/ima_template.c

···
 struct ima_template_desc *ima_template_desc_current(void)
 {
 	if (!ima_template)
-		ima_template = lookup_template_desc(IMA_TEMPLATE_IMA_NAME);
-
+		ima_template =
+		    lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE);
 	return ima_template;
 }