Mercurial > dropbear
annotate libtomcrypt/src/pk/rsa/rsa_sign_saltlen_get.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 | 6dba84798cd5 |
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rev | line source |
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1471
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1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
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2 * |
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3 * LibTomCrypt is a library that provides various cryptographic |
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4 * algorithms in a highly modular and flexible manner. |
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5 * |
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6 * The library is free for all purposes without any express |
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7 * guarantee it works. |
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8 */ |
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9 #include "tomcrypt.h" |
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10 |
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11 /** |
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12 @file rsa_sign_saltlen_get.c |
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13 Retrieve the maximum size of the salt, Steffen Jaeckel. |
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14 */ |
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15 |
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16 #ifdef LTC_MRSA |
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17 |
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18 /** |
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19 Retrieve the maximum possible size of the salt when creating a PKCS#1 PSS signature. |
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20 @param padding Type of padding (LTC_PKCS_1_PSS only) |
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21 @param hash_idx The index of the desired hash |
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22 @param key The RSA key |
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23 @return The maximum salt length in bytes or INT_MAX on error. |
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24 */ |
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25 int rsa_sign_saltlen_get_max_ex(int padding, int hash_idx, rsa_key *key) |
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26 { |
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27 int ret = INT_MAX; |
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28 LTC_ARGCHK(key != NULL); |
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29 |
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30 if ((hash_is_valid(hash_idx) == CRYPT_OK) && |
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31 (padding == LTC_PKCS_1_PSS)) |
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32 { |
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33 ret = rsa_get_size(key); |
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34 if (ret < INT_MAX) |
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35 { |
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36 ret -= (hash_descriptor[hash_idx].hashsize + 2); |
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37 } /* if */ |
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38 } /* if */ |
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39 |
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40 return ret; |
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41 } |
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42 |
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43 #endif |
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44 |
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45 /* ref: $Format:%D$ */ |
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46 /* git commit: $Format:%H$ */ |
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47 /* commit time: $Format:%ai$ */ |