server/tripe-admin.5.in: Document the `unsuitable-aead-cipher' warnings.

This was missed out of the earlier AEAD work.

diff --git a/server/tripe-admin.5.in b/server/tripe-admin.5.in
index cc97298..bd2cce8 100644 (file)
--- a/server/tripe-admin.5.in
+++ b/server/tripe-admin.5.in
@@ -1542,6 +1542,51 @@ The key specifies the use of an unknown serialization format
 for hashing group elements.  Maybe the key was generated wrongly, or
 maybe the version of Catacomb installed is too old.
 .SP
+.BI "KEYMGMT " which "-keyring " file " key " tag " unsuitable-aead-cipher " cipher "no-aad"
+The key specifies the use of an authenticated encryption scheme
+.I cipher
+which does not support the processing of additional authenticated data.
+The most prominent examples of such schemes are the
+.IB cipher -naclbox
+collection, where
+.I cipher
+is
+.BR salsa20 ,
+.BR salsa20/12 ,
+.BR salsa20/8 ,
+.BR chacha20 ,
+.BR chacha12 ,
+or
+.BR chacha8 ;
+use the
+.B naclbox
+bulk transform rather than
+.B aead
+for these
+(or switch to the IETF
+.IB cipher -poly1305
+schemes instead).
+.SP
+.BI "KEYMGMT " which "-keyring " file " key " tag " unsuitable-aead-cipher " cipher "nonce-too-small"
+The key specifies the use of an authenticated encryption scheme
+.I cipher
+which doesn't even allow a 5-byte (40-bit) nonce.  Catacomb doesn't
+implement any such limited AE schemes: you must be doing something
+strange.
+.SP
+.BI "KEYMGMT " which "-keyring " file " key " tag " unsuitable-aead-cipher " cipher "nonce-too-large"
+The key specifies the use of an authenticated encryption scheme
+.I cipher
+which doesn't support any nonce size smaller than 64 bytes (512 bits).
+Catacomb doesn't implement any such extravagant AE schemes: you must be
+doing something strange.
+.SP
+.BI "KEYMGMT " which "-keyring " file " key " tag " unsuitable-aead-cipher " cipher "nonempty-ciphertext-for-empty-message"
+The key specifies the use of an authenticated encryption scheme
+.I cipher
+which produces ciphertext output even when given a completely empty
+message.  Catacomb doesn't implement any such unhelpful AE schemes: you
+must be doing something strange.
 .SP
 .BI "KEYMGMT " which "-keyring " file " key " tag " " alg " " name " no-key-size " hashsz
 The