1 files changed, 58 insertions, 0 deletions
diff --git a/src/encauth/gcm/gcm_mult_h.c b/src/encauth/gcm/gcm_mult_h.c
new file mode 100644
index 0000000..8391e00
--- /dev/null
+++ b/src/encauth/gcm/gcm_mult_h.c
@@ -0,0 +1,58 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
+ */
+
+/**
+   @file gcm_mult_h.c
+   GCM implementation, do the GF mult, by Tom St Denis
+*/
+#include "tomcrypt.h"
+
+#if defined(GCM_MODE)
+/**
+  GCM multiply by H
+  @param gcm   The GCM state which holds the H value
+  @param I     The value to multiply H by
+ */
+void gcm_mult_h(gcm_state *gcm, unsigned char *I)
+{
+   unsigned char T[16];
+#ifdef GCM_TABLES
+   int x, y;
+#ifdef GCM_TABLES_SSE2
+   asm("movdqa (%0),%%xmm0"::"r"(&gcm->PC[0][I[0]][0]));
+   for (x = 1; x < 16; x++) {
+      asm("pxor (%0),%%xmm0"::"r"(&gcm->PC[x][I[x]][0]));
+   }
+   asm("movdqa %%xmm0,(%0)"::"r"(&T));
+#else
+   XMEMCPY(T, &gcm->PC[0][I[0]][0], 16);
+   for (x = 1; x < 16; x++) {
+#ifdef LTC_FAST
+       for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
+           *((LTC_FAST_TYPE *)(T + y)) ^= *((LTC_FAST_TYPE *)(&gcm->PC[x][I[x]][y]));
+       }
+#else
+       for (y = 0; y < 16; y++) {
+           T[y] ^= gcm->PC[x][I[x]][y];
+       }
+#endif /* LTC_FAST */
+   }
+#endif /* GCM_TABLES_SSE2 */
+#else     
+   gcm_gf_mult(gcm->H, I, T); 
+#endif
+   XMEMCPY(I, T, 16);
+}
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/encauth/gcm/gcm_mult_h.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/08/23 20:40:23 $ */