diff options
Diffstat (limited to 'ssh.c')
| -rw-r--r-- | ssh.c | 641 |
1 files changed, 357 insertions, 284 deletions
@@ -348,6 +348,10 @@ static void c_write (char *buf, int len) { from_backend(1, buf, len); } +static void c_write_str (char *buf) { + c_write(buf, strlen(buf)); +} + /* * Collect incoming data in the incoming packet buffer. * Decipher and verify the packet when it is completely read. @@ -1394,12 +1398,12 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break; case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break; case CIPHER_AES: - c_write("AES not supported in SSH1, falling back to 3DES\r\n", 49); + c_write_str("AES not supported in SSH1, falling back to 3DES\r\n"); cipher_type = SSH_CIPHER_3DES; break; } if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { - c_write("Selected cipher not supported, falling back to 3DES\r\n", 53); + c_write_str("Selected cipher not supported, falling back to 3DES\r\n"); cipher_type = SSH_CIPHER_3DES; } switch (cipher_type) { @@ -1439,7 +1443,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) static int pos = 0; static char c; if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { - c_write("login as: ", 10); + c_write_str("login as: "); ssh_send_ok = 1; while (pos >= 0) { crWaitUntil(!ispkt); @@ -1450,13 +1454,13 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) break; case 8: case 127: if (pos > 0) { - c_write("\b \b", 3); + c_write_str("\b \b"); pos--; } break; case 21: case 27: while (pos > 0) { - c_write("\b \b", 3); + c_write_str("\b \b"); pos--; } break; @@ -1473,7 +1477,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) break; } } - c_write("\r\n", 2); + c_write_str("\r\n"); username[strcspn(username, "\n\r")] = '\0'; } else { strncpy(username, cfg.username, 99); @@ -1488,7 +1492,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (flags & FLAG_INTERACTIVE && (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { strcat(userlog, "\r\n"); - c_write(userlog, strlen(userlog)); + c_write_str(userlog); } } } @@ -1585,10 +1589,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (pktin.type == SSH1_SMSG_SUCCESS) { logevent("Pageant's response accepted"); if (flags & FLAG_VERBOSE) { - c_write("Authenticated using RSA key \"", - 29); + c_write_str("Authenticated using RSA key \""); c_write(commentp, commentlen); - c_write("\" from agent\r\n", 14); + c_write_str("\" from agent\r\n"); } authed = TRUE; } else @@ -1624,7 +1627,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { logevent("TIS authentication declined"); if (flags & FLAG_INTERACTIVE) - c_write("TIS authentication refused.\r\n", 29); + c_write_str("TIS authentication refused.\r\n"); } else { int challengelen = ((pktin.body[0] << 24) | (pktin.body[1] << 16) | @@ -1646,7 +1649,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) crWaitUntil(ispkt); if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { logevent("CryptoCard authentication declined"); - c_write("CryptoCard authentication refused.\r\n", 29); + c_write_str("CryptoCard authentication refused.\r\n"); } else { int challengelen = ((pktin.body[0] << 24) | (pktin.body[1] << 16) | @@ -1668,10 +1671,10 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { char *comment = NULL; if (flags & FLAG_VERBOSE) - c_write("Trying public key authentication.\r\n", 35); + c_write_str("Trying public key authentication.\r\n"); if (!rsakey_encrypted(cfg.keyfile, &comment)) { if (flags & FLAG_VERBOSE) - c_write("No passphrase required.\r\n", 25); + c_write_str("No passphrase required.\r\n"); goto tryauth; } sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); @@ -1691,7 +1694,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) crReturn(1); } } else { - c_write(prompt, strlen(prompt)); + c_write_str(prompt); pos = 0; ssh_send_ok = 1; while (pos >= 0) { @@ -1719,7 +1722,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) break; } } - c_write("\r\n", 2); + c_write_str("\r\n"); } tryauth: @@ -1736,13 +1739,13 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) tried_publickey = 1; i = loadrsakey(cfg.keyfile, &pubkey, password); if (i == 0) { - c_write("Couldn't load public key from ", 30); - c_write(cfg.keyfile, strlen(cfg.keyfile)); - c_write(".\r\n", 3); + c_write_str("Couldn't load public key from "); + c_write_str(cfg.keyfile); + c_write_str(".\r\n"); continue; /* go and try password */ } if (i == -1) { - c_write("Wrong passphrase.\r\n", 19); + c_write_str("Wrong passphrase.\r\n"); tried_publickey = 0; continue; /* try again */ } @@ -1755,7 +1758,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) crWaitUntil(ispkt); if (pktin.type == SSH1_SMSG_FAILURE) { - c_write("Server refused our public key.\r\n", 32); + c_write_str("Server refused our public key.\r\n"); continue; /* go and try password */ } if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { @@ -1781,8 +1784,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) crWaitUntil(ispkt); if (pktin.type == SSH1_SMSG_FAILURE) { if (flags & FLAG_VERBOSE) - c_write("Failed to authenticate with our public key.\r\n", - 45); + c_write_str("Failed to authenticate with our public key.\r\n"); continue; /* go and try password */ } else if (pktin.type != SSH1_SMSG_SUCCESS) { bombout(("Bizarre response to RSA authentication response")); @@ -1798,7 +1800,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) crWaitUntil(ispkt); if (pktin.type == SSH1_SMSG_FAILURE) { if (flags & FLAG_VERBOSE) - c_write("Access denied\r\n", 15); + c_write_str("Access denied\r\n"); logevent("Authentication refused"); } else if (pktin.type == SSH1_MSG_DISCONNECT) { logevent("Received disconnect request"); @@ -1904,7 +1906,7 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { bombout(("Protocol confusion")); crReturnV; } else if (pktin.type == SSH1_SMSG_FAILURE) { - c_write("Server refused to allocate pty\r\n", 32); + c_write_str("Server refused to allocate pty\r\n"); ssh_editing = ssh_echoing = 1; } logevent("Allocated pty"); @@ -1919,7 +1921,7 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { bombout(("Protocol confusion")); crReturnV; } else if (pktin.type == SSH1_SMSG_FAILURE) { - c_write("Server refused to compress\r\n", 32); + c_write_str("Server refused to compress\r\n"); } logevent("Started compression"); ssh1_compressing = TRUE; @@ -2629,7 +2631,15 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) static enum { AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD } method; + static enum { + AUTH_TYPE_NONE, + AUTH_TYPE_PUBLICKEY, + AUTH_TYPE_PUBLICKEY_OFFER_LOUD, + AUTH_TYPE_PUBLICKEY_OFFER_QUIET, + AUTH_TYPE_PASSWORD + } type; static int gotit, need_pw, can_pubkey, can_passwd, tried_pubkey_config; + static int we_are_in; static char username[100]; static char pwprompt[200]; static char password[100]; @@ -2649,14 +2659,39 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) } /* - * Get a username. + * We repeat this whole loop, including the username prompt, + * until we manage a successful authentication. If the user + * types the wrong _password_, they are sent back to the + * beginning to try another username. (If they specify a + * username in the config, they are never asked, even if they + * do give a wrong password.) + * + * I think this best serves the needs of + * + * - the people who have no configuration, no keys, and just + * want to try repeated (username,password) pairs until they + * type both correctly + * + * - people who have keys and configuration but occasionally + * need to fall back to passwords + * + * - people with a key held in Pageant, who might not have + * logged in to a particular machine before; so they want to + * type a username, and then _either_ their key will be + * accepted, _or_ they will type a password. If they mistype + * the username they will want to be able to get back and + * retype it! */ - { - static int pos = 0; + do { + static int pos; static char c; + /* + * Get a username. + */ + pos = 0; if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { - c_write("login as: ", 10); + c_write_str("login as: "); ssh_send_ok = 1; while (pos >= 0) { crWaitUntilV(!ispkt); @@ -2667,13 +2702,13 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) break; case 8: case 127: if (pos > 0) { - c_write("\b \b", 3); + c_write_str("\b \b"); pos--; } break; case 21: case 27: while (pos > 0) { - c_write("\b \b", 3); + c_write_str("\b \b"); pos--; } break; @@ -2690,7 +2725,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) break; } } - c_write("\r\n", 2); + c_write_str("\r\n"); username[strcspn(username, "\n\r")] = '\0'; } else { char stuff[200]; @@ -2698,295 +2733,333 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) username[99] = '\0'; if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { sprintf(stuff, "Using username \"%s\".\r\n", username); - c_write(stuff, strlen(stuff)); + c_write_str(stuff); } } - } - - /* - * Send an authentication request using method "none": (a) - * just in case it succeeds, and (b) so that we know what - * authentication methods we can usefully try next. - */ - ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(username); - ssh2_pkt_addstring("ssh-connection"); /* service requested */ - ssh2_pkt_addstring("none"); /* method */ - ssh2_pkt_send(); - logevent("Attempting null authentication"); - gotit = FALSE; - while (1) { /* - * Wait for the result of the last authentication request. + * Send an authentication request using method "none": (a) + * just in case it succeeds, and (b) so that we know what + * authentication methods we can usefully try next. */ - if (!gotit) - crWaitUntilV(ispkt); - while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { - /* FIXME: should support this */ - crWaitUntilV(ispkt); - } - if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { - logevent("Access granted"); - break; - } + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("none"); /* method */ + ssh2_pkt_send(); + type = AUTH_TYPE_NONE; + gotit = FALSE; + we_are_in = FALSE; - if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { - bombout(("Strange packet received during authentication: type %d", - pktin.type)); - } + tried_pubkey_config = FALSE; - gotit = FALSE; + while (1) { + /* + * Wait for the result of the last authentication request. + */ + if (!gotit) + crWaitUntilV(ispkt); + while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { + /* FIXME: should support this */ + crWaitUntilV(ispkt); + } + if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { + logevent("Access granted"); + we_are_in = TRUE; + break; + } - /* - * OK, we're now sitting on a USERAUTH_FAILURE message, so - * we can look at the string in it and know what we can - * helpfully try next. - */ - { - char *methods; - int methlen; - ssh2_pkt_getstring(&methods, &methlen); - if (!ssh2_pkt_getbool()) { - /* - * FIXME: these messages are often inappropriate. - */ - c_write("Access denied\r\n", 15); - logevent("Access denied"); - } else { - c_write("Authentication partially successful\r\n", 37); - logevent("Authentication partially successful"); + if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { + bombout(("Strange packet received during authentication: type %d", + pktin.type)); } - can_pubkey = in_commasep_string("publickey", methods, methlen); - can_passwd = in_commasep_string("password", methods, methlen); - } + gotit = FALSE; - method = 0; + /* + * OK, we're now sitting on a USERAUTH_FAILURE message, so + * we can look at the string in it and know what we can + * helpfully try next. + */ + { + char *methods; + int methlen; + ssh2_pkt_getstring(&methods, &methlen); + if (!ssh2_pkt_getbool()) { + /* + * We have received an unequivocal Access + * Denied. This can translate to a variety of + * messages: + * + * - if we'd just tried "none" authentication, + * it's not worth printing anything at all + * + * - if we'd just tried a public key _offer_, + * the message should be "Server refused our + * key" (or no message at all if the key + * came from Pageant) + * + * - if we'd just tried anything else, the + * message really should be "Access denied". + * + * Additionally, if we'd just tried password + * authentication, we should break out of this + * whole loop so as to go back to the username + * prompt. + */ + if (type == AUTH_TYPE_NONE) { + /* do nothing */ + } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || + type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { + if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) + c_write_str("Server refused our key\r\n"); + logevent("Server refused public key"); + } else { + c_write_str("Access denied\r\n"); + logevent("Access denied"); + if (type == AUTH_TYPE_PASSWORD) { + we_are_in = FALSE; + break; + } + } + } else { + c_write_str("Further authentication required\r\n"); + logevent("Further authentication required"); + } - if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) { - unsigned char *pub_blob; - char *algorithm, *comment; - int pub_blob_len; + can_pubkey = in_commasep_string("publickey", methods, methlen); + can_passwd = in_commasep_string("password", methods, methlen); + } - tried_pubkey_config = TRUE; + method = 0; - /* - * Try the public key supplied in the configuration. - * - * First, offer the public blob to see if the server is - * willing to accept it. - */ - pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, - &pub_blob_len); - if (pub_blob) { - ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(username); - ssh2_pkt_addstring("ssh-connection"); /* service requested */ - ssh2_pkt_addstring("publickey");/* method */ - ssh2_pkt_addbool(FALSE); /* no signature included */ - ssh2_pkt_addstring(algorithm); - ssh2_pkt_addstring_start(); - ssh2_pkt_addstring_data(pub_blob, pub_blob_len); - ssh2_pkt_send(); - logevent("Offered public key"); /* FIXME */ + if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) { + unsigned char *pub_blob; + char *algorithm, *comment; + int pub_blob_len; - crWaitUntilV(ispkt); - if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { - gotit = TRUE; - continue; /* key refused; give up on it */ - } + tried_pubkey_config = TRUE; - logevent("Offer of public key accepted"); /* - * Actually attempt a serious authentication using - * the key. + * Try the public key supplied in the configuration. + * + * First, offer the public blob to see if the server is + * willing to accept it. */ - if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { - sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment); - need_pw = TRUE; - } else { - need_pw = FALSE; - } - method = AUTH_PUBLICKEY_FILE; - } - } - - if (!method && can_passwd) { - method = AUTH_PASSWORD; - sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost); - need_pw = TRUE; - } + pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, + &pub_blob_len); + if (pub_blob) { + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("publickey");/* method */ + ssh2_pkt_addbool(FALSE); /* no signature included */ + ssh2_pkt_addstring(algorithm); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(pub_blob, pub_blob_len); + ssh2_pkt_send(); + logevent("Offered public key"); /* FIXME */ + + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { + gotit = TRUE; + type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; + continue; /* key refused; give up on it */ + } - if (need_pw) { - if (ssh_get_password) { - if (!ssh_get_password(pwprompt, password, sizeof(password))) { + logevent("Offer of public key accepted"); /* - * get_password failed to get a password (for - * example because one was supplied on the command - * line which has already failed to work). - * Terminate. + * Actually attempt a serious authentication using + * the key. */ - logevent("No more passwords to try"); - ssh_state = SSH_STATE_CLOSED; - crReturnV; + if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { + sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment); + need_pw = TRUE; + } else { + need_pw = FALSE; + } + c_write_str("Authenticating with public key \""); + c_write_str(comment); + c_write_str("\"\r\n"); + method = AUTH_PUBLICKEY_FILE; } - } else { - static int pos = 0; - static char c; - - c_write(pwprompt, strlen(pwprompt)); - ssh_send_ok = 1; - - pos = 0; - while (pos >= 0) { - crWaitUntilV(!ispkt); - while (inlen--) switch (c = *in++) { - case 10: case 13: - password[pos] = 0; - pos = -1; - break; - case 8: case 127: - if (pos > 0) - pos--; - break; - case 21: case 27: - pos = 0; - break; - case 3: case 4: - random_save_seed(); - exit(0); - break; - default: - if (((c >= ' ' && c <= '~') || - ((unsigned char)c >= 160)) && pos < 40) - password[pos++] = c; - break; + } + + if (!method && can_passwd) { + method = AUTH_PASSWORD; + sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost); + need_pw = TRUE; + } + + if (need_pw) { + if (ssh_get_password) { + if (!ssh_get_password(pwprompt, password, sizeof(password))) { + /* + * get_password failed to get a password (for + * example because one was supplied on the command + * line which has already failed to work). + * Terminate. + */ + logevent("No more passwords to try"); + ssh_state = SSH_STATE_CLOSED; + crReturnV; + } + } else { + static int pos = 0; + static char c; + + c_write_str(pwprompt); + ssh_send_ok = 1; + + pos = 0; + while (pos >= 0) { + crWaitUntilV(!ispkt); + while (inlen--) switch (c = *in++) { + case 10: case 13: + password[pos] = 0; + pos = -1; + break; + case 8: case 127: + if (pos > 0) + pos--; + break; + case 21: case 27: + pos = 0; + break; + case 3: case 4: + random_save_seed(); + exit(0); + break; + default: + if (((c >= ' ' && c <= '~') || + ((unsigned char)c >= 160)) && pos < 40) + password[pos++] = c; + break; + } } + c_write_str("\r\n"); } - c_write("\r\n", 2); } - } - if (method == AUTH_PUBLICKEY_FILE) { - /* - * We have our passphrase. Now try the actual authentication. - */ - struct ssh2_userkey *key; + if (method == AUTH_PUBLICKEY_FILE) { + /* + * We have our passphrase. Now try the actual authentication. + */ + struct ssh2_userkey *key; - key = ssh2_load_userkey(cfg.keyfile, password); - if (key == SSH2_WRONG_PASSPHRASE) { - c_write("Wrong passphrase\r\n", 18); - tried_pubkey_config = FALSE; - /* Send a spurious AUTH_NONE to return to the top. */ - ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(username); - ssh2_pkt_addstring("ssh-connection"); /* service requested */ - ssh2_pkt_addstring("none"); /* method */ - ssh2_pkt_send(); - } else if (key == NULL) { - c_write("Unable to load private key\r\n",28); - tried_pubkey_config = TRUE; - /* Send a spurious AUTH_NONE to return to the top. */ - ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(username); - ssh2_pkt_addstring("ssh-connection"); /* service requested */ - ssh2_pkt_addstring("none"); /* method */ - ssh2_pkt_send(); - } else { - unsigned char *blob, *sigdata; - int blob_len, sigdata_len; + key = ssh2_load_userkey(cfg.keyfile, password); + if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { + if (key == SSH2_WRONG_PASSPHRASE) { + c_write_str("Wrong passphrase\r\n"); + tried_pubkey_config = FALSE; + } else { + c_write_str("Unable to load private key\r\n"); + tried_pubkey_config = TRUE; + } + /* Send a spurious AUTH_NONE to return to the top. */ + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("none"); /* method */ + ssh2_pkt_send(); + type = AUTH_TYPE_NONE; + } else { + unsigned char *blob, *sigdata; + int blob_len, sigdata_len; + /* + * We have loaded the private key and the server + * has announced that it's willing to accept it. + * Hallelujah. Generate a signature and send it. + */ + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(username); + ssh2_pkt_addstring("ssh-connection"); /* service requested */ + ssh2_pkt_addstring("publickey"); /* method */ + ssh2_pkt_addbool(TRUE); + ssh2_pkt_addstring(key->alg->name); + blob = key->alg->public_blob(key->data, &blob_len); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(blob, blob_len); + sfree(blob); + + /* + * The data to be signed is: + * + * string session-id + * + * followed by everything so far placed in the + * outgoing packet. + */ + sigdata_len = pktout.length - 5 + 4 + 20; + sigdata = smalloc(sigdata_len); + PUT_32BIT(sigdata, 20); + memcpy(sigdata+4, ssh2_session_id, 20); + memcpy(sigdata+24, pktout.data+5, pktout.length-5); + blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(blob, blob_len); + sfree(blob); + sfree(sigdata); + + ssh2_pkt_send(); + type = AUTH_TYPE_PUBLICKEY; + } + } else if (method == AUTH_PASSWORD) { /* - * We have loaded the private key and the server - * has announced that it's willing to accept it. - * Hallelujah. Generate a signature and send it. + * We send the password packet lumped tightly together with + * an SSH_MSG_IGNORE packet. The IGNORE packet contains a + * string long enough to make the total length of the two + * packets constant. This should ensure that a passive + * listener doing traffic analyis can't work out the length + * of the password. + * + * For this to work, we need an assumption about the + * maximum length of the password packet. I think 256 is + * pretty conservative. Anyone using a password longer than + * that probably doesn't have much to worry about from + * people who find out how long their password is! */ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); ssh2_pkt_addstring(username); ssh2_pkt_addstring("ssh-connection"); /* service requested */ - ssh2_pkt_addstring("publickey"); /* method */ - ssh2_pkt_addbool(TRUE); - ssh2_pkt_addstring(key->alg->name); - blob = key->alg->public_blob(key->data, &blob_len); - ssh2_pkt_addstring_start(); - ssh2_pkt_addstring_data(blob, blob_len); - sfree(blob); - + ssh2_pkt_addstring("password"); + ssh2_pkt_addbool(FALSE); + ssh2_pkt_addstring(password); + ssh2_pkt_defer(); /* - * The data to be signed is: - * - * string session-id - * - * followed by everything so far placed in the - * outgoing packet. + * We'll include a string that's an exact multiple of the + * cipher block size. If the cipher is NULL for some + * reason, we don't do this trick at all because we gain + * nothing by it. */ - sigdata_len = pktout.length - 5 + 4 + 20; - sigdata = smalloc(sigdata_len); - PUT_32BIT(sigdata, 20); - memcpy(sigdata+4, ssh2_session_id, 20); - memcpy(sigdata+24, pktout.data+5, pktout.length-5); - blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len); - ssh2_pkt_addstring_start(); - ssh2_pkt_addstring_data(blob, blob_len); - sfree(blob); - sfree(sigdata); - - ssh2_pkt_send(); - } - } else if (method == AUTH_PASSWORD) { - /* - * We send the password packet lumped tightly together with - * an SSH_MSG_IGNORE packet. The IGNORE packet contains a - * string long enough to make the total length of the two - * packets constant. This should ensure that a passive - * listener doing traffic analyis can't work out the length - * of the password. - * - * For this to work, we need an assumption about the - * maximum length of the password packet. I think 256 is - * pretty conservative. Anyone using a password longer than - * that probably doesn't have much to worry about from - * people who find out how long their password is! - */ - ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(username); - ssh2_pkt_addstring("ssh-connection"); /* service requested */ - ssh2_pkt_addstring("password"); - ssh2_pkt_addbool(FALSE); - ssh2_pkt_addstring(password); - ssh2_pkt_defer(); - /* - * We'll include a string that's an exact multiple of the - * cipher block size. If the cipher is NULL for some - * reason, we don't do this trick at all because we gain - * nothing by it. - */ - if (cscipher) { - int i, j; - ssh2_pkt_init(SSH2_MSG_IGNORE); - ssh2_pkt_addstring_start(); - for (i = deferred_len; i <= 256; i += cscipher->blksize) { - for (j = 0; j < cscipher->blksize; j++) { - char c = (char)random_byte(); - ssh2_pkt_addstring_data(&c, 1); + if (cscipher) { + int i, j; + ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(); + for (i = deferred_len; i <= 256; i += cscipher->blksize) { + for (j = 0; j < cscipher->blksize; j++) { + char c = (char)random_byte(); + ssh2_pkt_addstring_data(&c, 1); + } } + ssh2_pkt_defer(); } - ssh2_pkt_defer(); + ssh2_pkt_defersend(); + type = AUTH_TYPE_PASSWORD; + } else { + c_write_str("No supported authentication methods left to try!\r\n"); + logevent("No supported authentications offered. Disconnecting"); + ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); + ssh2_pkt_addstring("No supported authentication methods available"); + ssh2_pkt_addstring("en"); /* language tag */ + ssh2_pkt_send(); + ssh_state = SSH_STATE_CLOSED; + crReturnV; } - ssh2_pkt_defersend(); - } else { - c_write("No supported authentication methods left to try!\r\n", 50); - logevent("No supported authentications offered. Disconnecting"); - ssh2_pkt_init(SSH2_MSG_DISCONNECT); - ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); - ssh2_pkt_addstring("No supported authentication methods available"); - ssh2_pkt_addstring("en"); /* language tag */ - ssh2_pkt_send(); - ssh_state = SSH_STATE_CLOSED; - crReturnV; } - } + } while (!we_are_in); /* * Now we're authenticated for the connection protocol. The @@ -3102,7 +3175,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) bombout(("Server got confused by pty request")); crReturnV; } - c_write("Server refused to allocate pty\r\n", 32); + c_write_str("Server refused to allocate pty\r\n"); ssh_editing = ssh_echoing = 1; } else { logevent("Allocated pty"); |