From 10f61ef8a2deafb3b801786ad37338c410ed21d7 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Sat, 17 Nov 2018 22:32:32 +0000
Subject: [PATCH] symm/keccak1600.c: Add new function to overwrite the state.

This is somewhat more useful for implementing duplex-style
constructions.
---
 debian/catacomb2.symbols |  1 +
 symm/keccak1600.c        | 29 +++++++++++++++++++++++++++++
 symm/keccak1600.h        | 20 ++++++++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/debian/catacomb2.symbols b/debian/catacomb2.symbols
index b6ffba11..44c2da7d 100644
--- a/debian/catacomb2.symbols
+++ b/debian/catacomb2.symbols
@@ -4042,6 +4042,7 @@ libcatacomb.so.2 catacomb2 #MINVER#
 	keccak1600_init@Base 2.4.0
 	keccak1600_p@Base 2.4.0
 	keccak1600_mix@Base 2.4.0
+	keccak1600_set@Base 2.5.99~
 	keccak1600_extract@Base 2.4.0
 
 ## sha3 common
diff --git a/symm/keccak1600.c b/symm/keccak1600.c
index 499ab4f6..c2d82926 100644
--- a/symm/keccak1600.c
+++ b/symm/keccak1600.c
@@ -589,6 +589,35 @@ void keccak1600_mix(keccak1600_state *s, const kludge64 *p, size_t n)
     { a = TO_LANE(p[i]); XOR_LANE(s->S[i], s->S[i], a); }
 }
 
+/* --- @keccak1600_set@ --- *
+ *
+ * Arguments:	@keccak1600_state *s@ = a state to update
+ *		@const kludge64 *p@ = pointer to 64-bit words to mix in
+ *		@size_t n@ = size of the input, in 64-bit words
+ *
+ * Returns:	---
+ *
+ * Use:		Stores data into a %$\Keccak[r, 1600 - r]$% state.  Note that
+ *		it's the caller's responsibility to pass in no more than
+ *		%$r$% bits of data.
+ *
+ *		This is not the operation you wanted for ordinary hashing.
+ *		It's provided for the use of higher-level protocols which use
+ *		duplexing and other fancy sponge features.
+ */
+
+void keccak1600_set(keccak1600_state *s, const kludge64 *p, size_t n)
+{
+  uint32 m = COMPL_MASK;
+  unsigned i;
+  lane a;
+
+  for (i = 0; i < n; i++) {
+    a = TO_LANE(p[i]); if (m&1) NOT_LANE(a, a);
+    s->S[i] = a; m >>= 1;
+  }
+}
+
 /* --- @keccak1600_extract@ --- *
  *
  * Arguments:	@const keccak1600_state *s@ = a state to extract output from
diff --git a/symm/keccak1600.h b/symm/keccak1600.h
index 2867be96..f5aad98d 100644
--- a/symm/keccak1600.h
+++ b/symm/keccak1600.h
@@ -112,6 +112,26 @@ extern void keccak1600_init(keccak1600_state */*s*/);
 extern void keccak1600_mix(keccak1600_state */*s*/,
 			   const kludge64 */*p*/, size_t /*n*/);
 
+/* --- @keccak1600_set@ --- *
+ *
+ * Arguments:	@keccak1600_state *s@ = a state to update
+ *		@const kludge64 *p@ = pointer to 64-bit words to mix in
+ *		@size_t n@ = size of the input, in 64-bit words
+ *
+ * Returns:	---
+ *
+ * Use:		Stores data into a %$\Keccak[r, 1600 - r]$% state.  Note that
+ *		it's the caller's responsibility to pass in no more than
+ *		%$r$% bits of data.
+ *
+ *		This is not the operation you wanted for ordinary hashing.
+ *		It's provided for the use of higher-level protocols which use
+ *		duplexing and other fancy sponge features.
+ */
+
+extern void keccak1600_set(keccak1600_state */*s*/,
+			   const kludge64 */*p*/, size_t /*n*/);
+
 /* --- @keccak1600_extract@ --- *
  *
  * Arguments:	@const keccak1600_state *s@ = a state to extract output from
-- 
2.11.0