ABNF for Noise protocol names

1 files changed, 19 insertions, 3 deletions

diff --git a/patterns/grammar-abnf.txt b/patterns/grammar-abnf.txt
index f1c2c04..e968d6f 100644
--- a/patterns/grammar-abnf.txt
+++ b/patterns/grammar-abnf.txt
@@ -7,6 +7,9 @@
 ; The "pattern-single" element is intended for applications that wish to
 ; provide an API to define the specific pattern to use in a handshake.
 ;
+; The "protocol-name" lexical token describes the structure of Noise
+; protocol names in ABNF.
+;
 ; Productions that start with "extension-" apply to extension features like
 ; Hybrid Forward Secrecy and are not part of the core Noise standard.
 
@@ -18,7 +21,7 @@ pattern-single      = wsp pattern wsp
 
 pattern             = header wsp [pre-message wsp "..." wsp] messages
 
-header              = name wsp "(" wsp params wsp ")" wsp ":"
+header              = "Noise_" pattern-name wsp "(" wsp params wsp ")" wsp ":"
 
 params              = param *(wsp "," wsp param)
 
@@ -49,9 +52,22 @@ extension-token     = "f" / "ff"        ; Hybrid Forward Secrecy
 
 ; Lexical tokens
 
-name                = "Noise_" name-component *("+" name-component)
+protocol-name       = "Noise_" pattern-name "_" dh-algorithms
+                      "_" cipher-algorithms "_" hash-algorithms
+
+pattern-name        = base-pattern-name [modifier-name *("+" modifier-name)]
+
+base-pattern-name   = 1*(%x41-5A)           ; 1 or more uppercase letters
+
+modifier-name       = 1*(%x61-7A / DIGIT)   ; Lower case and digits
+
+dh-algorithms       = name-component *("+" name-component)
+
+cipher-algorithms   = name-component *("+" name-component)
+
+hash-algorithms     = name-component *("+" name-component)
 
-name-component      = 1*(ALPHA / DIGIT)
+name-component      = 1*(ALPHA / DIGIT / "/")
 
 wsp                 = *(WSP / eol / comment)