From a3183fb91c12c72d91e1b9f6ed1cd0968c238ea9aca50126fa75a2a1f7917679 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Mon, 21 Apr 2025 10:14:04 +0300
Subject: [PATCH] Excess kexp15

---
 spec/cm/kem-gost3410-hkdf.texi                             | 7 +++----
 tcl/schemas/encrypted.tcl                                  | 2 +-
 ...{kem-gost3410-hkdf-kexp15.tcl => kem-gost3410-hkdf.tcl} | 4 ++--
 3 files changed, 6 insertions(+), 7 deletions(-)
 rename tcl/schemas/{kem-gost3410-hkdf-kexp15.tcl => kem-gost3410-hkdf.tcl} (76%)

diff --git a/spec/cm/kem-gost3410-hkdf.texi b/spec/cm/kem-gost3410-hkdf.texi
index 6db2006..e9e3057 100644
--- a/spec/cm/kem-gost3410-hkdf.texi
+++ b/spec/cm/kem-gost3410-hkdf.texi
@@ -3,16 +3,15 @@
 @nodedescription GOST R 34.10+HKDF KEM
 @subsubsection GOST R 34.10+HKDF KEM
 
-@verbatiminclude ../tcl/schemas/kem-gost3410-hkdf-kexp15.tcl
+@verbatiminclude ../tcl/schemas/kem-gost3410-hkdf.tcl
 
 GOST R 34.10-2012 VKO parameter set A/C ("gost3410-256A", "gost3410-512C")
 must be used for DH operation, with UKM taken from the structure. VKO's
-output is 512- or 1024-bit @code{BE(X)||BE(Y)} point. It is used in HKDF
-and KExp15 (Р 1323565.1.017) key wrapping algorithm:
+output is 512- or 1024-bit @code{BE(X)||BE(Y)} point, used in HKDF below:
 
 @verbatim
 PRK = HKDF-Extract(Streebog-512, salt="", ikm=VKO(..., ukm=UKM))
-KEK= HKDF-Expand(Streebog-512, prk=PRK, info="cm/encrypted/gost3410-hkdf" || /id)
+KEK = HKDF-Expand(Streebog-512, prk=PRK, info="cm/encrypted/gost3410-hkdf" || /id)
 @end verbatim
 
 @code{/kem/*/cek} is wrapped with @ref{keywrap-kexp15} mechanism.
diff --git a/tcl/schemas/encrypted.tcl b/tcl/schemas/encrypted.tcl
index 7a91171..d4833e5 100644
--- a/tcl/schemas/encrypted.tcl
+++ b/tcl/schemas/encrypted.tcl
@@ -18,6 +18,6 @@ kem {
 
 schema-include fpr.tcl
 schema-include kem-with-encap.tcl
-schema-include kem-gost3410-hkdf-kexp15.tcl
+schema-include kem-gost3410-hkdf.tcl
 schema-include kem-balloon-blake2b-hkdf.tcl
 schema-include kem-pbkdf2.tcl
diff --git a/tcl/schemas/kem-gost3410-hkdf-kexp15.tcl b/tcl/schemas/kem-gost3410-hkdf.tcl
similarity index 76%
rename from tcl/schemas/kem-gost3410-hkdf-kexp15.tcl
rename to tcl/schemas/kem-gost3410-hkdf.tcl
index 08268b2..8cce4ec 100644
--- a/tcl/schemas/kem-gost3410-hkdf-kexp15.tcl
+++ b/tcl/schemas/kem-gost3410-hkdf.tcl
@@ -1,5 +1,5 @@
-kem-gost3410-hkdf-kexp15 {
-    {field a {str} =gost3410-hkdf-kexp15}
+kem-gost3410-hkdf {
+    {field a {str} =gost3410-hkdf}
     {field cek {bin} >0} {# wrapped CEK}
     {field ukm {bin} len=16} {# additional keying material}
     {field pub {bin} >0} {# sender's ephemeral public key}
-- 
2.48.1