Mercurial > dropbear
view crypto_desc.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 | 750ec4ec4cbe |
children | 34d9d3c022ce |
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#include "includes.h" #include "dbutil.h" #include "crypto_desc.h" #include "ltc_prng.h" #include "ecc.h" #if DROPBEAR_LTC_PRNG int dropbear_ltc_prng = -1; #endif /* Register the compiled in ciphers. * This should be run before using any of the ciphers/hashes */ void crypto_init() { const struct ltc_cipher_descriptor *regciphers[] = { #if DROPBEAR_AES &aes_desc, #endif #if DROPBEAR_BLOWFISH &blowfish_desc, #endif #if DROPBEAR_TWOFISH &twofish_desc, #endif #if DROPBEAR_3DES &des3_desc, #endif NULL }; const struct ltc_hash_descriptor *reghashes[] = { /* we need sha1 for hostkey stuff regardless */ &sha1_desc, #if DROPBEAR_MD5_HMAC &md5_desc, #endif #if DROPBEAR_SHA256 &sha256_desc, #endif #if DROPBEAR_SHA384 &sha384_desc, #endif #if DROPBEAR_SHA512 &sha512_desc, #endif NULL }; int i; for (i = 0; regciphers[i] != NULL; i++) { if (register_cipher(regciphers[i]) == -1) { dropbear_exit("Error registering crypto"); } } for (i = 0; reghashes[i] != NULL; i++) { if (register_hash(reghashes[i]) == -1) { dropbear_exit("Error registering crypto"); } } #if DROPBEAR_LTC_PRNG dropbear_ltc_prng = register_prng(&dropbear_prng_desc); if (dropbear_ltc_prng == -1) { dropbear_exit("Error registering crypto"); } #endif #if DROPBEAR_ECC ltc_mp = ltm_desc; dropbear_ecc_fill_dp(); #endif }