Mercurial > dropbear
annotate libtommath/bn_mp_from_ubin.c @ 1715:3974f087d9c0
Disallow leading lines before the ident for server (#102)
Per RFC4253 4.2 clients must be able to process other lines of data
before the version string, server behavior is not defined neither
with MUST/SHOULD nor with MAY.
If server process up to 50 lines too - it may cause too long hanging
session with invalid/evil client that consume host resources and
potentially may lead to DDoS on poor embedded boxes.
Let's require first line from client to be version string and fail
early if it's not - matches both RFC and real OpenSSH behavior.
author | Vladislav Grishenko <themiron@users.noreply.github.com> |
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date | Mon, 15 Jun 2020 18:22:18 +0500 |
parents | 1051e4eea25a |
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rev | line source |
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1692
1051e4eea25a
Update LibTomMath to 1.2.0 (#84)
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1 #include "tommath_private.h" |
1051e4eea25a
Update LibTomMath to 1.2.0 (#84)
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2 #ifdef BN_MP_FROM_UBIN_C |
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3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */ |
1051e4eea25a
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4 /* SPDX-License-Identifier: Unlicense */ |
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5 |
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6 /* reads a unsigned char array, assumes the msb is stored first [big endian] */ |
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7 mp_err mp_from_ubin(mp_int *a, const unsigned char *buf, size_t size) |
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8 { |
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9 mp_err err; |
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10 |
1051e4eea25a
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11 /* make sure there are at least two digits */ |
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12 if (a->alloc < 2) { |
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13 if ((err = mp_grow(a, 2)) != MP_OKAY) { |
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14 return err; |
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15 } |
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16 } |
1051e4eea25a
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17 |
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18 /* zero the int */ |
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19 mp_zero(a); |
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20 |
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21 /* read the bytes in */ |
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22 while (size-- > 0u) { |
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23 if ((err = mp_mul_2d(a, 8, a)) != MP_OKAY) { |
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24 return err; |
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25 } |
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26 |
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27 #ifndef MP_8BIT |
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28 a->dp[0] |= *buf++; |
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29 a->used += 1; |
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30 #else |
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31 a->dp[0] = (*buf & MP_MASK); |
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32 a->dp[1] |= ((*buf++ >> 7) & 1u); |
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33 a->used += 2; |
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34 #endif |
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35 } |
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36 mp_clamp(a); |
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37 return MP_OKAY; |
1051e4eea25a
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38 } |
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39 #endif |