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authorMatt Johnston <matt@ucc.asn.au>2018-02-09 21:44:05 +0800
committerMatt Johnston <matt@ucc.asn.au>2018-02-09 21:44:05 +0800
commit4f2eb1914bdac3ed3ee504ad86061281dbe0d074 (patch)
tree078293375c3f3ee2d485cf9559a08d65d460786a /libtomcrypt/src/encauth/ccm/ccm_done.c
parentd72f50ff3284e15124a0f233c26339229fe305ac (diff)
Update to libtomcrypt 1.18.1, merged with Dropbear changes
Diffstat (limited to 'libtomcrypt/src/encauth/ccm/ccm_done.c')
-rw-r--r--libtomcrypt/src/encauth/ccm/ccm_done.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/libtomcrypt/src/encauth/ccm/ccm_done.c b/libtomcrypt/src/encauth/ccm/ccm_done.c
new file mode 100644
index 0000000..797b7d9
--- /dev/null
+++ b/libtomcrypt/src/encauth/ccm/ccm_done.c
@@ -0,0 +1,65 @@
+/* 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.
+ */
+#include "tomcrypt.h"
+
+#ifdef LTC_CCM_MODE
+
+/**
+ Terminate a CCM stream
+ @param ccm The CCM 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 ccm_done(ccm_state *ccm,
+ unsigned char *tag, unsigned long *taglen)
+{
+ unsigned long x, y;
+ int err;
+
+ LTC_ARGCHK(ccm != NULL);
+
+ /* Check all data have been processed */
+ if (ccm->ptlen != ccm->current_ptlen) {
+ return CRYPT_ERROR;
+ }
+
+ LTC_ARGCHK(tag != NULL);
+ LTC_ARGCHK(taglen != NULL);
+
+ if (ccm->x != 0) {
+ if ((err = cipher_descriptor[ccm->cipher].ecb_encrypt(ccm->PAD, ccm->PAD, &ccm->K)) != CRYPT_OK) {
+ return err;
+ }
+ }
+
+ /* setup CTR for the TAG (zero the count) */
+ for (y = 15; y > 15 - ccm->L; y--) {
+ ccm->ctr[y] = 0x00;
+ }
+ if ((err = cipher_descriptor[ccm->cipher].ecb_encrypt(ccm->ctr, ccm->CTRPAD, &ccm->K)) != CRYPT_OK) {
+ return err;
+ }
+
+ cipher_descriptor[ccm->cipher].done(&ccm->K);
+
+ /* store the TAG */
+ for (x = 0; x < 16 && x < *taglen; x++) {
+ tag[x] = ccm->PAD[x] ^ ccm->CTRPAD[x];
+ }
+ *taglen = x;
+
+ return CRYPT_OK;
+}
+
+#endif
+
+/* ref: $Format:%D$ */
+/* git commit: $Format:%H$ */
+/* commit time: $Format:%ai$ */