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view libtommath/bn_mp_dr_setup.c @ 1705:5b701bf529aa

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Fix ChaCha20 on 32-bit platforms (#99) * Fix ChaCha20 on 32-bit platforms On 32-bit platforms with old compiler STORE64H() parameter is not auto-expanded to 64-bit value, causing wrong IV data. Spotted on BCM4706 MIPS32r2 with GCC 4.2.4: Exit before auth: Integrity error (bad packet size 2065808956) * Fix Chacha20-Poly1305 and AES-GCM debug messages Functions were renamed earlier and trace messages - not.
author Vladislav Grishenko <themiron@users.noreply.github.com>
date Fri, 29 May 2020 18:26:22 +0500
parents 1051e4eea25a
children
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#include "tommath_private.h"
#ifdef BN_MP_DR_SETUP_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

/* determines the setup value */
void mp_dr_setup(const mp_int *a, mp_digit *d)
{
   /* the casts are required if MP_DIGIT_BIT is one less than
    * the number of bits in a mp_digit [e.g. MP_DIGIT_BIT==31]
    */
   *d = (mp_digit)(((mp_word)1 << (mp_word)MP_DIGIT_BIT) - (mp_word)a->dp[0]);
}

#endif