view libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c @ 1855:35d504d59c05

Implement server-side support for sk-ecdsa U2F-backed keys (#142) * Implement server-side support for sk-ecdsa U2F-backed keys * Fix out-of-bounds read on normal ecdsa-sha2-[identifier] keys * Fix one more potential out-of-bounds read * Check if nistp256 curve is used in sk-ecdsa-sha2- key It's the only allowed curve per PROTOCOL.u2f specification * Implement server-side support for sk-ed25519 FIDO2-backed keys * Keys with type sk-* make no sense as host keys, so they should be disabled * fix typo * Make sk-ecdsa call buf_ecdsa_verify This reduces code duplication, the SK code just handles the different message format. * Reduce sk specific code The application id can be stored in signkey, then we don't need to call sk-specific functions from svr-authpubkey * Remove debugging output, which causes compilation errors with DEBUG_TRACE disabled * Proper cleanup of sk_app Co-authored-by: Matt Johnston <[email protected]>
author egor-duda <egor-duda@users.noreply.github.com>
date Sat, 22 Jan 2022 16:53:04 +0300
parents 6dba84798cd5
children
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/* 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


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