crypto: gf128mul - fix some comments
Fix incorrect references to GF(128) instead of GF(2^128), as these are
two entirely different fields, and fix a few other incorrect comments.
Cc: Alex Cope <alexcope@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/gf128mul.c b/crypto/gf128mul.c
index 72015fe..d9e3eec 100644
--- a/crypto/gf128mul.c
+++ b/crypto/gf128mul.c
@@ -44,7 +44,7 @@
---------------------------------------------------------------------------
Issue 31/01/2006
- This file provides fast multiplication in GF(128) as required by several
+ This file provides fast multiplication in GF(2^128) as required by several
cryptographic authentication modes
*/
@@ -116,9 +116,10 @@
static const u16 gf128mul_table_lle[256] = gf128mul_dat(xda_lle);
static const u16 gf128mul_table_bbe[256] = gf128mul_dat(xda_bbe);
-/* These functions multiply a field element by x, by x^4 and by x^8
- * in the polynomial field representation. It uses 32-bit word operations
- * to gain speed but compensates for machine endianess and hence works
+/*
+ * The following functions multiply a field element by x or by x^8 in
+ * the polynomial field representation. They use 64-bit word operations
+ * to gain speed but compensate for machine endianness and hence work
* correctly on both styles of machine.
*/
@@ -251,7 +252,7 @@
/* This version uses 64k bytes of table space.
A 16 byte buffer has to be multiplied by a 16 byte key
- value in GF(128). If we consider a GF(128) value in
+ value in GF(2^128). If we consider a GF(2^128) value in
the buffer's lowest byte, we can construct a table of
the 256 16 byte values that result from the 256 values
of this byte. This requires 4096 bytes. But we also
@@ -330,7 +331,7 @@
/* This version uses 4k bytes of table space.
A 16 byte buffer has to be multiplied by a 16 byte key
- value in GF(128). If we consider a GF(128) value in a
+ value in GF(2^128). If we consider a GF(2^128) value in a
single byte, we can construct a table of the 256 16 byte
values that result from the 256 values of this byte.
This requires 4096 bytes. If we take the highest byte in