Mercurial > dropbear

annotate libtommath/bn_mp_to_ubin.c @ 1928:333688ec53d0

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Handle ecdsa-sk flags, reject no-touch For the time being Dropbear will only allow SK auth with default parameters, user-presence needs to be set. In future handling of authorized_keys option "no-touch-required" can be added. This code would also be refactored to share between ecdsa and ed25519 once I get hardware/emulation to test ed25519.
author Matt Johnston <matt@ucc.asn.au>
date Wed, 30 Mar 2022 21:06:15 +0800
parents 1051e4eea25a
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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1692
1051e4eea25a Update LibTomMath to 1.2.0 (#84)
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1 #include "tommath_private.h"
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2 #ifdef BN_MP_TO_UBIN_C
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3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
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4 /* SPDX-License-Identifier: Unlicense */
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5
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6 /* store in unsigned [big endian] format */
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7 mp_err mp_to_ubin(const mp_int *a, unsigned char *buf, size_t maxlen, size_t *written)
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8 {
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9 size_t x, count;
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10 mp_err err;
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11 mp_int t;
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12
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13 count = mp_ubin_size(a);
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14 if (count > maxlen) {
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15 return MP_BUF;
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16 }
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17
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18 if ((err = mp_init_copy(&t, a)) != MP_OKAY) {
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19 return err;
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20 }
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21
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22 for (x = count; x --> 0u;) {
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23 #ifndef MP_8BIT
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24 buf[x] = (unsigned char)(t.dp[0] & 255u);
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25 #else
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26 buf[x] = (unsigned char)(t.dp[0] | ((t.dp[1] & 1u) << 7));
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27 #endif
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28 if ((err = mp_div_2d(&t, 8, &t, NULL)) != MP_OKAY) {
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29 goto LBL_ERR;
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30 }
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31 }
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32
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33 if (written != NULL) {
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34 *written = count;
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35 }
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36
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37 LBL_ERR:
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38 mp_clear(&t);
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39 return err;
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40 }
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41 #endif