If unsure, say N.
+# This option selects XFRM_ALGO along with the AH authentication algorithms that
+# RFC 8221 lists as MUST be implemented.
+config XFRM_AH
+ tristate
+ select XFRM_ALGO
+ select CRYPTO
+ select CRYPTO_HMAC
+ select CRYPTO_SHA256
+
+# This option selects XFRM_ALGO along with the ESP encryption and authentication
+# algorithms that RFC 8221 lists as MUST be implemented.
+config XFRM_ESP
+ tristate
+ select XFRM_ALGO
+ select CRYPTO
+ select CRYPTO_AES
+ select CRYPTO_AUTHENC
+ select CRYPTO_CBC
+ select CRYPTO_ECHAINIV
+ select CRYPTO_GCM
+ select CRYPTO_HMAC
+ select CRYPTO_SEQIV
+ select CRYPTO_SHA256
+
config XFRM_IPCOMP
tristate
select XFRM_ALGO