Mercurial > dropbear
diff common-kex.c @ 1676:d5cdc60db08e
ext-info handling for server-sig-algs
only client side is handled
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Tue, 19 May 2020 00:31:41 +0800 |
parents | ba6fc7afe1c5 |
children | 4b4cfc92c5b7 |
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--- a/common-kex.c Sun May 17 23:58:31 2020 +0800 +++ b/common-kex.c Tue May 19 00:31:41 2020 +0800 @@ -820,21 +820,33 @@ int goodguess = 0; int allgood = 1; /* we AND this with each goodguess and see if its still true after */ - -#if DROPBEAR_KEXGUESS2 - enum kexguess2_used kexguess2 = KEXGUESS2_LOOK; -#else - enum kexguess2_used kexguess2 = KEXGUESS2_NO; -#endif + int kexguess2 = 0; buf_incrpos(ses.payload, 16); /* start after the cookie */ memset(ses.newkeys, 0x0, sizeof(*ses.newkeys)); /* kex_algorithms */ - algo = buf_match_algo(ses.payload, sshkex, &kexguess2, &goodguess); +#if DROPBEAR_KEXGUESS2 + if (buf_has_algo(ses.payload, KEXGUESS2_ALGO_NAME) == DROPBEAR_SUCCESS) { + kexguess2 = 1; + } +#endif + + /* Determine if SSH_MSG_EXT_INFO messages should be sent. + Should be done for the first key exchange. */ + if (!ses.kexstate.donefirstkex) { + if (IS_DROPBEAR_SERVER) { + if (buf_has_algo(ses.payload, SSH_EXT_INFO_C) == DROPBEAR_SUCCESS) { + ses.allow_ext_info = 1; + } + } + } + + algo = buf_match_algo(ses.payload, sshkex, kexguess2, &goodguess); allgood &= goodguess; - if (algo == NULL || algo->val == KEXGUESS2_ALGO_ID) { + if (algo == NULL || algo->data == NULL) { + /* kexguess2, ext-info-c, ext-info-s should not match negotiation */ erralgo = "kex"; goto error; } @@ -843,7 +855,7 @@ ses.newkeys->algo_kex = algo->data; /* server_host_key_algorithms */ - algo = buf_match_algo(ses.payload, sshhostkey, &kexguess2, &goodguess); + algo = buf_match_algo(ses.payload, sshhostkey, kexguess2, &goodguess); allgood &= goodguess; if (algo == NULL) { erralgo = "hostkey";