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Diffstat (limited to 'core/lib/libtomcrypt/src/encauth/gcm/gcm_done.c')
-rw-r--r--core/lib/libtomcrypt/src/encauth/gcm/gcm_done.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/encauth/gcm/gcm_done.c b/core/lib/libtomcrypt/src/encauth/gcm/gcm_done.c
new file mode 100644
index 0000000..28d0909
--- /dev/null
+++ b/core/lib/libtomcrypt/src/encauth/gcm/gcm_done.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2001-2007, Tom St Denis
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* 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://libtom.org
+ */
+
+/**
+ @file gcm_done.c
+ GCM implementation, Terminate the stream, by Tom St Denis
+*/
+#include "tomcrypt.h"
+
+#ifdef LTC_GCM_MODE
+
+/**
+ Terminate a GCM stream
+ @param gcm The GCM state
+ @param tag [out] The destination for the MAC tag
+ @param taglen [in/out] The length of the MAC tag
+ @return CRYPT_OK on success
+ */
+int gcm_done(gcm_state *gcm,
+ unsigned char *tag, unsigned long *taglen)
+{
+ unsigned long x;
+ int err;
+
+ LTC_ARGCHK(gcm != NULL);
+ LTC_ARGCHK(tag != NULL);
+ LTC_ARGCHK(taglen != NULL);
+
+ if (gcm->buflen > 16 || gcm->buflen < 0) {
+ return CRYPT_INVALID_ARG;
+ }
+
+ if ((err = cipher_is_valid(gcm->cipher)) != CRYPT_OK) {
+ return err;
+ }
+
+
+ if (gcm->mode != LTC_GCM_MODE_TEXT) {
+ return CRYPT_INVALID_ARG;
+ }
+
+ /* handle remaining ciphertext */
+ if (gcm->buflen) {
+ gcm->pttotlen += gcm->buflen * CONST64(8);
+ gcm_mult_h(gcm, gcm->X);
+ }
+
+ /* length */
+ STORE64H(gcm->totlen, gcm->buf);
+ STORE64H(gcm->pttotlen, gcm->buf+8);
+ for (x = 0; x < 16; x++) {
+ gcm->X[x] ^= gcm->buf[x];
+ }
+ gcm_mult_h(gcm, gcm->X);
+
+ /* encrypt original counter */
+ if ((err = cipher_descriptor[gcm->cipher]->ecb_encrypt(gcm->Y_0, gcm->buf, &gcm->K)) != CRYPT_OK) {
+ return err;
+ }
+ for (x = 0; x < 16 && x < *taglen; x++) {
+ tag[x] = gcm->buf[x] ^ gcm->X[x];
+ }
+ *taglen = x;
+
+ cipher_descriptor[gcm->cipher]->done(&gcm->K);
+
+ return CRYPT_OK;
+}
+
+#endif
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/encauth/gcm/gcm_done.c,v $ */
+/* $Revision: 1.11 $ */
+/* $Date: 2007/05/12 14:32:35 $ */