From fabde503df784065f11b109e9f60bba86fec777e Mon Sep 17 00:00:00 2001 From: Sumit Bose Date: Wed, 28 Apr 2010 10:01:06 +0200 Subject: [PATCH] Add retry option to pam_sss --- src/man/pam_sss.8.xml | 17 ++++ src/sss_client/pam_sss.c | 239 ++++++++++++++++++++++++++++------------------ 2 files changed, 164 insertions(+), 92 deletions(-) diff --git a/src/man/pam_sss.8.xml b/src/man/pam_sss.8.xml index 9a68196..aed76e2 100644 --- a/src/man/pam_sss.8.xml +++ b/src/man/pam_sss.8.xml @@ -31,6 +31,9 @@ use_authtok + + retry=N + @@ -75,6 +78,20 @@ password module. + + + + + + If specified the user is asked another N times for a + password if authentication fails. Default is 0. + Please note that this option might not work as + expected if the application calling PAM handles the user + dialog on its own. A typical example is + sshd with + . + + diff --git a/src/sss_client/pam_sss.c b/src/sss_client/pam_sss.c index 8bd3c9e..e6ab477 100644 --- a/src/sss_client/pam_sss.c +++ b/src/sss_client/pam_sss.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -60,6 +61,8 @@ #define PW_RESET_MSG_FILENAME_TEMPLATE SSSD_CONF_DIR"/customize/%s/pam_sss_pw_reset_message.%s" #define PW_RESET_MSG_MAX_SIZE 4096 +#define OPT_RETRY_KEY "retry=" + struct pam_items { const char* pam_service; const char* pam_user; @@ -205,6 +208,9 @@ static void overwrite_and_free_pam_items(struct pam_items *pi) pi->pam_newauthtok = NULL; } + pi->pamstack_authtok = NULL; + pi->pamstack_oldauthtok = NULL; + free(pi->domain_name); } @@ -1201,8 +1207,10 @@ static int prompt_new_password(pam_handle_t *pamh, struct pam_items *pi) } static void eval_argv(pam_handle_t *pamh, int argc, const char **argv, - uint32_t *flags) + uint32_t *flags, int *retries) { + char *ep; + for (; argc-- > 0; ++argv) { if (strcmp(*argv, "forward_pass") == 0) { *flags |= FLAGS_FORWARD_PASS; @@ -1210,6 +1218,28 @@ static void eval_argv(pam_handle_t *pamh, int argc, const char **argv, *flags |= FLAGS_USE_FIRST_PASS; } else if (strcmp(*argv, "use_authtok") == 0) { *flags |= FLAGS_USE_AUTHTOK; + } else if (strncmp(*argv, OPT_RETRY_KEY, strlen(OPT_RETRY_KEY)) == 0) { + if (*(*argv+6) == '\0') { + logger(pamh, LOG_ERR, "Missing argument to option retry."); + *retries = 0; + } else { + errno = 0; + *retries = strtol(*argv+6, &ep, 10); + if (errno != 0) { + D(("strtol failed [%d][%s]", errno, strerror(errno))); + *retries = 0; + } + if (*ep != '\0') { + logger(pamh, LOG_ERR, "Argument to option retry contains " + "extra characters."); + *retries = 0; + } + if (*retries < 0) { + logger(pamh, LOG_ERR, "Argument to option retry must not " + "be negative."); + *retries = 0; + } + } } else { logger(pamh, LOG_WARNING, "unknown option: %s", *argv); } @@ -1334,12 +1364,14 @@ static int pam_sss(enum sss_cli_command task, pam_handle_t *pamh, struct pam_items pi; uint32_t flags = 0; int *exp_data; + bool retry = false; + int retries = 0; bindtextdomain(PACKAGE, LOCALEDIR); D(("Hello pam_sssd: %d", task)); - eval_argv(pamh, argc, argv, &flags); + eval_argv(pamh, argc, argv, &flags, &retries); ret = get_pam_items(pamh, &pi); if (ret != PAM_SUCCESS) { @@ -1347,106 +1379,129 @@ static int pam_sss(enum sss_cli_command task, pam_handle_t *pamh, return ret; } - switch(task) { - case SSS_PAM_AUTHENTICATE: - ret = get_authtok_for_authentication(pamh, &pi, flags); - if (ret != PAM_SUCCESS) { - D(("failed to get authentication token: %s", - pam_strerror(pamh, ret))); - return ret; - } - break; - case SSS_PAM_CHAUTHTOK: - ret = get_authtok_for_password_change(pamh, &pi, flags, pam_flags); - if (ret != PAM_SUCCESS) { - D(("failed to get tokens for password change: %s", - pam_strerror(pamh, ret))); - return ret; - } - if (pam_flags & PAM_PRELIM_CHECK) { - task = SSS_PAM_CHAUTHTOK_PRELIM; - } - break; - case SSS_PAM_ACCT_MGMT: - case SSS_PAM_SETCRED: - case SSS_PAM_OPEN_SESSION: - case SSS_PAM_CLOSE_SESSION: - break; - default: - D(("Illegal task [%d]", task)); - return PAM_SYSTEM_ERR; - } - - pam_status = send_and_receive(pamh, &pi, task); - - switch (task) { - case SSS_PAM_AUTHENTICATE: - /* We allow sssd to send the return code PAM_NEW_AUTHTOK_REQD during - * authentication, see sss_cli.h for details */ - if (pam_status == PAM_NEW_AUTHTOK_REQD) { - D(("Authtoken expired, trying to change it")); - - exp_data = malloc(sizeof(int)); - if (exp_data == NULL) { - D(("malloc failed.")); - pam_status = PAM_BUF_ERR; - break; - } - *exp_data = 1; + do { + retry = false; - pam_status = pam_set_data(pamh, PWEXP_FLAG, exp_data, - free_exp_data); - if (pam_status != PAM_SUCCESS) { - D(("pam_set_data failed.")); - } - } - break; - case SSS_PAM_ACCT_MGMT: - if (pam_status == PAM_SUCCESS && - pam_get_data(pamh, PWEXP_FLAG, (const void **) &exp_data) == - PAM_SUCCESS) { - ret = do_pam_conversation(pamh, PAM_TEXT_INFO, - _("Password expired. Change your password now."), - NULL, NULL); + switch(task) { + case SSS_PAM_AUTHENTICATE: + ret = get_authtok_for_authentication(pamh, &pi, flags); if (ret != PAM_SUCCESS) { - D(("do_pam_conversation failed.")); + D(("failed to get authentication token: %s", + pam_strerror(pamh, ret))); + return ret; } - pam_status = PAM_NEW_AUTHTOK_REQD; - } - break; - case SSS_PAM_CHAUTHTOK: - if (pam_status != PAM_SUCCESS && pam_status != PAM_USER_UNKNOWN) { - ret = pam_set_item(pamh, PAM_AUTHTOK, NULL); + break; + case SSS_PAM_CHAUTHTOK: + ret = get_authtok_for_password_change(pamh, &pi, flags, pam_flags); if (ret != PAM_SUCCESS) { - D(("Failed to unset PAM_AUTHTOK [%s]", - pam_strerror(pamh,ret))); + D(("failed to get tokens for password change: %s", + pam_strerror(pamh, ret))); + return ret; } - ret = pam_set_item(pamh, PAM_OLDAUTHTOK, NULL); - if (ret != PAM_SUCCESS) { - D(("Failed to unset PAM_OLDAUTHTOK [%s]", - pam_strerror(pamh,ret))); + if (pam_flags & PAM_PRELIM_CHECK) { + task = SSS_PAM_CHAUTHTOK_PRELIM; } - } - break; - case SSS_PAM_CHAUTHTOK_PRELIM: - if (pam_status == PAM_PERM_DENIED && pi.pam_authtok_size == 0 && - getuid() == 0 && - pam_get_data(pamh, PWEXP_FLAG, (const void **) &exp_data) != - PAM_SUCCESS) { - - ret = select_pw_reset_message(pamh, &pi); - if (ret != 0) { - D(("select_pw_reset_message failed.\n")); + break; + case SSS_PAM_ACCT_MGMT: + case SSS_PAM_SETCRED: + case SSS_PAM_OPEN_SESSION: + case SSS_PAM_CLOSE_SESSION: + break; + default: + D(("Illegal task [%d]", task)); + return PAM_SYSTEM_ERR; + } + + pam_status = send_and_receive(pamh, &pi, task); + + switch (task) { + case SSS_PAM_AUTHENTICATE: + /* We allow sssd to send the return code PAM_NEW_AUTHTOK_REQD during + * authentication, see sss_cli.h for details */ + if (pam_status == PAM_NEW_AUTHTOK_REQD) { + D(("Authtoken expired, trying to change it")); + + exp_data = malloc(sizeof(int)); + if (exp_data == NULL) { + D(("malloc failed.")); + pam_status = PAM_BUF_ERR; + break; + } + *exp_data = 1; + + pam_status = pam_set_data(pamh, PWEXP_FLAG, exp_data, + free_exp_data); + if (pam_status != PAM_SUCCESS) { + D(("pam_set_data failed.")); + } } - } - default: - /* nothing to do */ - break; - } + break; + case SSS_PAM_ACCT_MGMT: + if (pam_status == PAM_SUCCESS && + pam_get_data(pamh, PWEXP_FLAG, (const void **) &exp_data) == + PAM_SUCCESS) { + ret = do_pam_conversation(pamh, PAM_TEXT_INFO, + _("Password expired. Change your password now."), + NULL, NULL); + if (ret != PAM_SUCCESS) { + D(("do_pam_conversation failed.")); + } + pam_status = PAM_NEW_AUTHTOK_REQD; + } + break; + case SSS_PAM_CHAUTHTOK: + if (pam_status != PAM_SUCCESS && pam_status != PAM_USER_UNKNOWN) { + ret = pam_set_item(pamh, PAM_AUTHTOK, NULL); + if (ret != PAM_SUCCESS) { + D(("Failed to unset PAM_AUTHTOK [%s]", + pam_strerror(pamh,ret))); + } + ret = pam_set_item(pamh, PAM_OLDAUTHTOK, NULL); + if (ret != PAM_SUCCESS) { + D(("Failed to unset PAM_OLDAUTHTOK [%s]", + pam_strerror(pamh,ret))); + } + } + break; + case SSS_PAM_CHAUTHTOK_PRELIM: + if (pam_status == PAM_PERM_DENIED && pi.pam_authtok_size == 0 && + getuid() == 0 && + pam_get_data(pamh, PWEXP_FLAG, (const void **) &exp_data) != + PAM_SUCCESS) { + + ret = select_pw_reset_message(pamh, &pi); + if (ret != 0) { + D(("select_pw_reset_message failed.\n")); + } + } + default: + /* nothing to do */ + break; + } + overwrite_and_free_pam_items(&pi); + D(("retries [%d].", retries)); - overwrite_and_free_pam_items(&pi); + if (pam_status != PAM_SUCCESS && + (task == SSS_PAM_AUTHENTICATE || task == SSS_PAM_CHAUTHTOK_PRELIM) && + retries > 0) { + retry = true; + retries--; + + flags &= !FLAGS_USE_FIRST_PASS; + ret = pam_set_item(pamh, PAM_AUTHTOK, NULL); + if (ret != PAM_SUCCESS) { + D(("Failed to unset PAM_AUTHTOK [%s]", + pam_strerror(pamh,ret))); + } + ret = pam_set_item(pamh, PAM_OLDAUTHTOK, NULL); + if (ret != PAM_SUCCESS) { + D(("Failed to unset PAM_OLDAUTHTOK [%s]", + pam_strerror(pamh,ret))); + } + } + } while(retry); return pam_status; } -- 1.6.6.1