diff --git a/doc/man-sections/client-options.rst b/doc/man-sections/client-options.rst index b75fe5b..a06948e 100644 --- a/doc/man-sections/client-options.rst +++ b/doc/man-sections/client-options.rst @@ -541,12 +541,15 @@ Valid syntax: :: - static-challenge text echo + static-challenge text echo [format] The ``text`` challenge text is presented to the user which describes what information is requested. The ``echo`` flag indicates if the user's input should be echoed on the screen. Valid ``echo`` values are - :code:`0` or :code:`1`. + :code:`0` or :code:`1`. The optional ``format`` indicates whether + the password and response should be combined using the SCRV1 protocol + (``format`` = :code:`scrv1`) or simply concatenated (``format`` = :code:`concat`). + :code:`scrv1` is the default. See management-notes.txt in the OpenVPN distribution for a description of the OpenVPN challenge/response protocol. diff --git a/doc/management-notes.txt b/doc/management-notes.txt index b9947fa..b55135a 100644 --- a/doc/management-notes.txt +++ b/doc/management-notes.txt @@ -1320,14 +1320,20 @@ OpenVPN's --static-challenge option is used to provide the challenge text to OpenVPN and indicate whether or not the response -should be echoed. +should be echoed and how the response should be combined with the +password. When credentials are needed and the --static-challenge option is used, the management interface will send: - >PASSWORD:Need 'Auth' username/password SC:, + >PASSWORD:Need 'Auth' username/password SC:, - ECHO: "1" if response should be echoed, "0" to not echo + flag: an integer whose least significant bit is the ECHO flag and + the next significant bit is the FORMAT flag. + ECHO = (flag & 0x1) is 1 if response should be echoed, 0 to not echo + FORMAT = (flag & 0x2) is 1 if response should be concatenated with + password as plain text, 0 if response and password should be encoded + as described below. Thus flag could take values 0, 1, 2, or 3. TEXT: challenge text that should be shown to the user to facilitate their response @@ -1342,8 +1348,9 @@ The management interface client in this case should add the static challenge text to the auth dialog followed by a field for the user to -enter a response. Then the management interface client should pack the -password and response together into an encoded password and send: +enter a response. If flag = 0 or 1 (i.e., FORMAT=0), the management +interface client should pack the password and response together into +an encoded password and send: username "Auth" password "Auth" "SCRV1::" @@ -1354,6 +1361,12 @@ the user. The and/or the can be empty strings. +If flag = 2 or 3 (i.e., FORMAT=1), the client should simply concatenate +password and response with no separator and send: + + username "Auth" + password "Auth" "" + (As in all username/password responses described in the "COMMAND -- password and username" section above, the username can be in quotes, and special characters such as double quotes or backslashes must be @@ -1361,10 +1374,15 @@ For example, if user "foo" entered "bar" as the password and 8675309 as the PIN, the following management interface commands should be -issued: +issued if flag = 0 or 1 (i.e., FORMAT = 0): username "Auth" foo password "Auth" "SCRV1:YmFy:ODY3NTMwOQ==" ("YmFy" is the base 64 encoding of "bar" and "ODY3NTMwOQ==" is the base 64 encoding of "8675309".) + +or, if flag = 2 or 3 (i.e., FORMAT = 1): + + username "Auth" foo + password "Auth" "bar8675309" diff --git a/src/openvpn/manage.c b/src/openvpn/manage.c index 24f3121..05b5a1a 100644 --- a/src/openvpn/manage.c +++ b/src/openvpn/manage.c @@ -3544,7 +3544,8 @@ if (sc) { buf_printf(&alert_msg, " SC:%d,%s", - BOOL_CAST(flags & GET_USER_PASS_STATIC_CHALLENGE_ECHO), + BOOL_CAST(flags & GET_USER_PASS_STATIC_CHALLENGE_ECHO) + |(BOOL_CAST(flags & GET_USER_PASS_STATIC_CHALLENGE_CONCAT) << 1), sc); } diff --git a/src/openvpn/misc.c b/src/openvpn/misc.c index 598fbae..516b1ed 100644 --- a/src/openvpn/misc.c +++ b/src/openvpn/misc.c @@ -438,17 +438,28 @@ { msg(M_FATAL, "ERROR: could not retrieve static challenge response"); } - if (openvpn_base64_encode(up->password, strlen(up->password), &pw64) == -1 - || openvpn_base64_encode(response, strlen(response), &resp64) == -1) + if (!(flags & GET_USER_PASS_STATIC_CHALLENGE_CONCAT)) { - msg(M_FATAL, "ERROR: could not base64-encode password/static_response"); + if (openvpn_base64_encode(up->password, strlen(up->password), &pw64) == -1 + || openvpn_base64_encode(response, strlen(response), &resp64) == -1) + { + msg(M_FATAL, "ERROR: could not base64-encode password/static_response"); + } + buf_set_write(&packed_resp, (uint8_t *)up->password, USER_PASS_LEN); + buf_printf(&packed_resp, "SCRV1:%s:%s", pw64, resp64); + string_clear(pw64); + free(pw64); + string_clear(resp64); + free(resp64); } - buf_set_write(&packed_resp, (uint8_t *)up->password, USER_PASS_LEN); - buf_printf(&packed_resp, "SCRV1:%s:%s", pw64, resp64); - string_clear(pw64); - free(pw64); - string_clear(resp64); - free(resp64); + else + { + if (strlen(up->password) + strlen(response) >= USER_PASS_LEN) + { + msg(M_FATAL, "ERROR: could not concatenate password/static_response: string too long"); + } + strncat(up->password, response, USER_PASS_LEN - strlen(up->password) - 1); + } } #endif /* ifdef ENABLE_MANAGEMENT */ } diff --git a/src/openvpn/misc.h b/src/openvpn/misc.h index 963f3e6..f3b824e 100644 --- a/src/openvpn/misc.h +++ b/src/openvpn/misc.h @@ -91,6 +91,7 @@ */ struct static_challenge_info { #define SC_ECHO (1<<0) /* echo response when typed by user */ +#define SC_CONCAT (1<<1) /* concatenate password and response and do not base64 encode */ unsigned int flags; const char *challenge_text; @@ -117,6 +118,7 @@ #define GET_USER_PASS_STATIC_CHALLENGE_ECHO (1<<9) /* SCRV1 protocol -- echo response */ #define GET_USER_PASS_INLINE_CREDS (1<<10) /* indicates that auth_file is actually inline creds */ +#define GET_USER_PASS_STATIC_CHALLENGE_CONCAT (1<<11) /* indicates password and response should be concatenated */ /** * Retrieves the user credentials from various sources depending on the flags. diff --git a/src/openvpn/options.c b/src/openvpn/options.c index 64e67aa..295ed3d 100644 --- a/src/openvpn/options.c +++ b/src/openvpn/options.c @@ -518,8 +518,10 @@ " Add domains to DNS domain search list\n" "--auth-retry t : How to handle auth failures. Set t to\n" " none (default), interact, or nointeract.\n" - "--static-challenge t e : Enable static challenge/response protocol using\n" + "--static-challenge t e []: Enable static challenge/response protocol using\n" " challenge text t, with e indicating echo flag (0|1)\n" + " and optional argument scrv1 or concat to use SCRV1 protocol or" + " concatenate response with password. Default is scrv1.\n" "--connect-timeout n : when polling possible remote servers to connect to\n" " in a round-robin fashion, spend no more than n seconds\n" " waiting for a response before trying the next server.\n" @@ -7932,7 +7934,7 @@ auth_retry_set(msglevel, p[1]); } #ifdef ENABLE_MANAGEMENT - else if (streq(p[0], "static-challenge") && p[1] && p[2] && !p[3]) + else if (streq(p[0], "static-challenge") && p[1] && p[2] && !p[4]) { VERIFY_PERMISSION(OPT_P_GENERAL); options->sc_info.challenge_text = p[1]; @@ -7940,6 +7942,15 @@ { options->sc_info.flags |= SC_ECHO; } + if (p[3] && streq(p[3], "concat")) + { + options->sc_info.flags |= SC_CONCAT; + } + else if (p[3] && !streq(p[3], "scrv1")) + { + msg(msglevel, "--static-challenge: unknown format indicator '%s'", p[3]); + goto err; + } } #endif else if (streq(p[0], "msg-channel") && p[1]) diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c index e0e9591..25c6ccf 100644 --- a/src/openvpn/ssl.c +++ b/src/openvpn/ssl.c @@ -312,6 +312,10 @@ { flags |= GET_USER_PASS_STATIC_CHALLENGE_ECHO; } + if (sci->flags & SC_CONCAT) + { + flags |= GET_USER_PASS_STATIC_CHALLENGE_CONCAT; + } get_user_pass_cr(&auth_user_pass, auth_file, UP_TYPE_AUTH,