Mercurial > dropbear
changeset 686:983a817f8e41 insecure-nocrypto
- Only request "none" cipher after auth has succeeded
| author | Matt Johnston <matt@ucc.asn.au> |
|---|---|
| date | Thu, 17 May 2012 20:52:57 +0800 |
| parents | 5af8993f7529 |
| children | 91dd8328a3ff |
| files | cli-auth.c cli-session.c common-algo.c options.h session.h |
| diffstat | 5 files changed, 54 insertions(+), 15 deletions(-) [+] |
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--- a/cli-auth.c Thu May 17 08:33:11 2012 +0800 +++ b/cli-auth.c Thu May 17 20:52:57 2012 +0800 @@ -257,13 +257,9 @@ #endif #ifdef ENABLE_CLI_INTERACT_AUTH -#if defined(DROPBEAR_NONE_CIPHER) && !defined(ALLOW_NONE_PASSWORD_AUTH) if (ses.keys->trans.algo_crypt->cipherdesc == NULL) { fprintf(stderr, "Sorry, I won't let you use interactive auth unencrypted.\n"); - } - else -#endif - if (!finished && ses.authstate.authtypes & AUTH_TYPE_INTERACT) { + } else if (!finished && ses.authstate.authtypes & AUTH_TYPE_INTERACT) { if (cli_ses.auth_interact_failed) { finished = 0; } else { @@ -275,13 +271,9 @@ #endif #ifdef ENABLE_CLI_PASSWORD_AUTH -#if defined(DROPBEAR_NONE_CIPHER) && !defined(ALLOW_NONE_PASSWORD_AUTH) if (ses.keys->trans.algo_crypt->cipherdesc == NULL) { fprintf(stderr, "Sorry, I won't let you use password auth unencrypted.\n"); - } - else -#endif - if (!finished && ses.authstate.authtypes & AUTH_TYPE_PASSWORD) { + } else if (!finished && ses.authstate.authtypes & AUTH_TYPE_PASSWORD) { cli_auth_password(); finished = 1; cli_ses.lastauthtype = AUTH_TYPE_PASSWORD;
--- a/cli-session.c Thu May 17 08:33:11 2012 +0800 +++ b/cli-session.c Thu May 17 20:52:57 2012 +0800 @@ -133,6 +133,13 @@ cli_ses.lastprivkey = NULL; cli_ses.lastauthtype = 0; +#ifdef DROPBEAR_NONE_CIPHER + cli_ses.cipher_none_after_auth = get_algo_usable(sshciphers, "none"); + set_algo_usable(sshciphers, "none", 0); +#else + cli_ses.cipher_none_after_auth = 0; +#endif + /* For printing "remote host closed" for the user */ ses.remoteclosed = cli_remoteclosed; ses.buf_match_algo = cli_buf_match_algo; @@ -207,6 +214,14 @@ case USERAUTH_SUCCESS_RCVD: +#ifdef DROPBEAR_NONE_CIPHER + if (cli_ses.cipher_none_after_auth) + { + set_algo_usable(sshciphers, "none", 1); + send_msg_kexinit(); + } +#endif + if (cli_opts.backgrounded) { int devnull; /* keeping stdin open steals input from the terminal and
--- a/common-algo.c Thu May 17 08:33:11 2012 +0800 +++ b/common-algo.c Thu May 17 20:52:57 2012 +0800 @@ -301,6 +301,38 @@ buf_free(algolist); } +#ifdef DROPBEAR_NONE_CIPHER + +void +set_algo_usable(algo_type algos[], const char * algo_name, int usable) +{ + algo_type *a; + for (a = algos; a->name != NULL; a++) + { + if (strcmp(a->name, algo_name) == 0) + { + a->usable = usable; + return; + } + } +} + +int +get_algo_usable(algo_type algos[], const char * algo_name) +{ + algo_type *a; + for (a = algos; a->name != NULL; a++) + { + if (strcmp(a->name, algo_name) == 0) + { + return a->usable; + } + } + return 0; +} + +#endif // DROPBEAR_NONE_CIPHER + #ifdef ENABLE_USER_ALGO_LIST char * @@ -367,7 +399,8 @@ { *c = '\0'; try_add_algo(last_name, algos, algo_desc, new_algos, &num_ret); - last_name = c++; + c++; + last_name = c; } } try_add_algo(last_name, algos, algo_desc, new_algos, &num_ret);
--- a/options.h Thu May 17 08:33:11 2012 +0800 +++ b/options.h Thu May 17 20:52:57 2012 +0800 @@ -106,10 +106,6 @@ * the only safe auth method is public key. */ #define DROPBEAR_NONE_CIPHER -/* Define this to allow password authentication even when no encryption - * is being used. This can be unsafe */ -#define ALLOW_NONE_PASSWORD_AUTH - /* Message Integrity - at least one required. * Protocol RFC requires sha1 and recommends sha1-96. * sha1-96 is of use for slow links as it has a smaller overhead.
--- a/session.h Thu May 17 08:33:11 2012 +0800 +++ b/session.h Thu May 17 20:52:57 2012 +0800 @@ -269,6 +269,9 @@ int interact_request_received; /* flag whether we've received an info request from the server for interactive auth.*/ + + int cipher_none_after_auth; /* Set to 1 if the user requested "none" + auth */ #endif sign_key *lastprivkey;