X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fencauth%2Focb%2Focb_done_decrypt.c;fp=libtomcrypt%2Fsrc%2Fencauth%2Focb%2Focb_done_decrypt.c;h=357bd847ae92668bacf10df24b4c43552d9a4464;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c b/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c
new file mode 100644
index 0000000..357bd84
--- /dev/null
+++ b/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c
@@ -0,0 +1,78 @@
+/* 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.
+ */
+
+/**
+   @file ocb_done_decrypt.c
+   OCB implementation, terminate decryption, by Tom St Denis
+*/
+#include "tomcrypt.h"
+
+#ifdef LTC_OCB_MODE
+
+/**
+   Terminate a decrypting OCB state
+   @param ocb    The OCB state
+   @param ct     The ciphertext (if any)
+   @param ctlen  The length of the ciphertext (octets)
+   @param pt     [out] The plaintext
+   @param tag    The authentication tag (to compare against)
+   @param taglen The length of the authentication tag provided
+   @param stat    [out] The result of the tag comparison
+   @return CRYPT_OK if the process was successful regardless if the tag is valid
+*/
+int ocb_done_decrypt(ocb_state *ocb,
+                     const unsigned char *ct,  unsigned long ctlen,
+                           unsigned char *pt,
+                     const unsigned char *tag, unsigned long taglen, int *stat)
+{
+   int err;
+   unsigned char *tagbuf;
+   unsigned long tagbuflen;
+
+   LTC_ARGCHK(ocb  != NULL);
+   LTC_ARGCHK(pt   != NULL);
+   LTC_ARGCHK(ct   != NULL);
+   LTC_ARGCHK(tag  != NULL);
+   LTC_ARGCHK(stat != NULL);
+
+   /* default to failed */
+   *stat = 0;
+
+   /* allocate memory */
+   tagbuf = XMALLOC(MAXBLOCKSIZE);
+   if (tagbuf == NULL) {
+      return CRYPT_MEM;
+   }
+
+   tagbuflen = MAXBLOCKSIZE;
+   if ((err = s_ocb_done(ocb, ct, ctlen, pt, tagbuf, &tagbuflen, 1)) != CRYPT_OK) {
+      goto LBL_ERR;
+   }
+
+   if (taglen <= tagbuflen && XMEM_NEQ(tagbuf, tag, taglen) == 0) {
+      *stat = 1;
+   }
+
+   err = CRYPT_OK;
+LBL_ERR:
+#ifdef LTC_CLEAN_STACK
+   zeromem(tagbuf, MAXBLOCKSIZE);
+#endif
+
+   XFREE(tagbuf);
+
+   return err;
+}
+
+#endif
+
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */