From 640ba4fe0c5d7423431d649f8e5e6ac72341f4ab Mon Sep 17 00:00:00 2001

From: Sumit Bose <sbose@redhat.com>

Date: Fri, 28 Feb 2020 10:11:49 +0100

Subject: [PATCH] Do expiration warnings for all init_creds APIs

Move the password expiration warning code from gic_pwd.c to

get_in_tkt.c.  Call it from init_creds_step_reply() on successful

completion.

[ghudson@mit.edu: added test case; simplified doc comment; moved call

site to init_creds_step_reply(); rewrote commit message]

ticket: 8893 (new)

(cherry picked from commit e1efb890f7ac31b32c68ab816ef118dbfb5a8c7e)

(cherry picked from commit c136cfe050d203c910624573a33247fde2889b09)

---

 src/include/krb5/krb5.hin         |   9 ++-

 src/lib/krb5/krb/get_in_tkt.c     | 112 ++++++++++++++++++++++++++++++

 src/lib/krb5/krb/gic_pwd.c        | 110 -----------------------------

 src/lib/krb5/krb/t_expire_warn.c  |  47 +++++++++----

 src/lib/krb5/krb/t_expire_warn.py |  22 ++++--

 5 files changed, 165 insertions(+), 135 deletions(-)

diff --git a/src/include/krb5/krb5.hin b/src/include/krb5/krb5.hin

index 6355e6540..f8269fb17 100644

--- a/src/include/krb5/krb5.hin

+++ b/src/include/krb5/krb5.hin

@@ -7174,11 +7174,10 @@ typedef void

  *

  * Set a callback to receive password and account expiration times.

  *

- * This option only applies to krb5_get_init_creds_password().  @a cb will be

- * invoked if and only if credentials are successfully acquired.  The callback

- * will receive the @a context from the krb5_get_init_creds_password() call and

- * the @a data argument supplied with this API.  The remaining arguments should

- * be interpreted as follows:

+ * @a cb will be invoked if and only if credentials are successfully acquired.

+ * The callback will receive the @a context from the calling function and the

+ * @a data argument supplied with this API.  The remaining arguments should be

+ * interpreted as follows:

  *

  * If @a is_last_req is true, then the KDC reply contained last-req entries

  * which unambiguously indicated the password expiration, account expiration,

diff --git a/src/lib/krb5/krb/get_in_tkt.c b/src/lib/krb5/krb/get_in_tkt.c

index 870df62a1..cc0f70e83 100644

--- a/src/lib/krb5/krb/get_in_tkt.c

+++ b/src/lib/krb5/krb/get_in_tkt.c

@@ -1482,6 +1482,116 @@ accept_method_data(krb5_context context, krb5_init_creds_context ctx)

                                      ctx->method_padata);

 }

+/* Return the password expiry time indicated by enc_part2.  Set *is_last_req

+ * if the information came from a last_req value. */

+static void

+get_expiry_times(krb5_enc_kdc_rep_part *enc_part2, krb5_timestamp *pw_exp,

+                 krb5_timestamp *acct_exp, krb5_boolean *is_last_req)

+{

+    krb5_last_req_entry **last_req;

+    krb5_int32 lr_type;

+

+    *pw_exp = 0;

+    *acct_exp = 0;

+    *is_last_req = FALSE;

+

+    /* Look for last-req entries for password or account expiration. */

+    if (enc_part2->last_req) {

+        for (last_req = enc_part2->last_req; *last_req; last_req++) {

+            lr_type = (*last_req)->lr_type;

+            if (lr_type == KRB5_LRQ_ALL_PW_EXPTIME ||

+                lr_type == KRB5_LRQ_ONE_PW_EXPTIME) {

+                *is_last_req = TRUE;

+                *pw_exp = (*last_req)->value;

+            } else if (lr_type == KRB5_LRQ_ALL_ACCT_EXPTIME ||

+                       lr_type == KRB5_LRQ_ONE_ACCT_EXPTIME) {

+                *is_last_req = TRUE;

+                *acct_exp = (*last_req)->value;

+            }

+        }

+    }

+

+    /* If we didn't find any, use the ambiguous key_exp field. */

+    if (*is_last_req == FALSE)

+        *pw_exp = enc_part2->key_exp;

+}

+

+/*

+ * Send an appropriate warning prompter if as_reply indicates that the password

+ * is going to expire soon.  If an expire callback was provided, use that

+ * instead.

+ */

+static void

+warn_pw_expiry(krb5_context context, krb5_get_init_creds_opt *options,

+               krb5_prompter_fct prompter, void *data,

+               const char *in_tkt_service, krb5_kdc_rep *as_reply)

+{

+    krb5_error_code ret;

+    krb5_expire_callback_func expire_cb;

+    void *expire_data;

+    krb5_timestamp pw_exp, acct_exp, now;

+    krb5_boolean is_last_req;

+    krb5_deltat delta;

+    char ts[256], banner[1024];

+

+    if (as_reply == NULL || as_reply->enc_part2 == NULL)

+        return;

+

+    get_expiry_times(as_reply->enc_part2, &pw_exp, &acct_exp, &is_last_req);

+

+    k5_gic_opt_get_expire_cb(options, &expire_cb, &expire_data);

+    if (expire_cb != NULL) {

+        /* Invoke the expire callback and don't send prompter warnings. */

+        (*expire_cb)(context, expire_data, pw_exp, acct_exp, is_last_req);

+        return;

+    }

+

+    /* Don't warn if no password expiry value was sent. */

+    if (pw_exp == 0)

+        return;

+

+    /* Don't warn if the password is being changed. */

+    if (in_tkt_service && strcmp(in_tkt_service, "kadmin/changepw") == 0)

+        return;

+

+    /*

+     * If the expiry time came from a last_req field, assume the KDC wants us

+     * to warn.  Otherwise, warn only if the expiry time is less than a week

+     * from now.

+     */

+    ret = krb5_timeofday(context, &now;;

+    if (ret != 0)

+        return;

+    if (!is_last_req &&

+        (ts_after(now, pw_exp) || ts_delta(pw_exp, now) > 7 * 24 * 60 * 60))

+        return;

+

+    if (!prompter)

+        return;

+

+    ret = krb5_timestamp_to_string(pw_exp, ts, sizeof(ts));

+    if (ret != 0)

+        return;

+

+    delta = ts_delta(pw_exp, now);

+    if (delta < 3600) {

+        snprintf(banner, sizeof(banner),

+                 _("Warning: Your password will expire in less than one hour "

+                   "on %s"), ts);

+    } else if (delta < 86400 * 2) {

+        snprintf(banner, sizeof(banner),

+                 _("Warning: Your password will expire in %d hour%s on %s"),

+                 delta / 3600, delta < 7200 ? "" : "s", ts);

+    } else {

+        snprintf(banner, sizeof(banner),

+                 _("Warning: Your password will expire in %d days on %s"),

+                 delta / 86400, ts);

+    }

+

+    /* PROMPTER_INVOCATION */

+    (*prompter)(context, data, 0, banner, 0, 0);

+}

+

 static krb5_error_code

 init_creds_step_reply(krb5_context context,

                       krb5_init_creds_context ctx,

@@ -1693,6 +1803,8 @@ init_creds_step_reply(krb5_context context,

     /* success */

     ctx->complete = TRUE;

+    warn_pw_expiry(context, ctx->opt, ctx->prompter, ctx->prompter_data,

+                   ctx->in_tkt_service, ctx->reply);

 cleanup:

     krb5_free_pa_data(context, kdc_padata);

diff --git a/src/lib/krb5/krb/gic_pwd.c b/src/lib/krb5/krb/gic_pwd.c

index 14ce23ba4..54e0a8ebe 100644

--- a/src/lib/krb5/krb/gic_pwd.c

+++ b/src/lib/krb5/krb/gic_pwd.c

@@ -133,113 +133,6 @@ krb5_init_creds_set_password(krb5_context context,

     return 0;

 }

-/* Return the password expiry time indicated by enc_part2.  Set *is_last_req

- * if the information came from a last_req value. */

-static void

-get_expiry_times(krb5_enc_kdc_rep_part *enc_part2, krb5_timestamp *pw_exp,

-                 krb5_timestamp *acct_exp, krb5_boolean *is_last_req)

-{

-    krb5_last_req_entry **last_req;

-    krb5_int32 lr_type;

-

-    *pw_exp = 0;

-    *acct_exp = 0;

-    *is_last_req = FALSE;

-

-    /* Look for last-req entries for password or account expiration. */

-    if (enc_part2->last_req) {

-        for (last_req = enc_part2->last_req; *last_req; last_req++) {

-            lr_type = (*last_req)->lr_type;

-            if (lr_type == KRB5_LRQ_ALL_PW_EXPTIME ||

-                lr_type == KRB5_LRQ_ONE_PW_EXPTIME) {

-                *is_last_req = TRUE;

-                *pw_exp = (*last_req)->value;

-            } else if (lr_type == KRB5_LRQ_ALL_ACCT_EXPTIME ||

-                       lr_type == KRB5_LRQ_ONE_ACCT_EXPTIME) {

-                *is_last_req = TRUE;

-                *acct_exp = (*last_req)->value;

-            }

-        }

-    }

-

-    /* If we didn't find any, use the ambiguous key_exp field. */

-    if (*is_last_req == FALSE)

-        *pw_exp = enc_part2->key_exp;

-}

-

-/*

- * Send an appropriate warning prompter if as_reply indicates that the password

- * is going to expire soon.  If an expire callback was provided, use that

- * instead.

- */

-static void

-warn_pw_expiry(krb5_context context, krb5_get_init_creds_opt *options,

-               krb5_prompter_fct prompter, void *data,

-               const char *in_tkt_service, krb5_kdc_rep *as_reply)

-{

-    krb5_error_code ret;

-    krb5_expire_callback_func expire_cb;

-    void *expire_data;

-    krb5_timestamp pw_exp, acct_exp, now;

-    krb5_boolean is_last_req;

-    krb5_deltat delta;

-    char ts[256], banner[1024];

-

-    get_expiry_times(as_reply->enc_part2, &pw_exp, &acct_exp, &is_last_req);

-

-    k5_gic_opt_get_expire_cb(options, &expire_cb, &expire_data);

-    if (expire_cb != NULL) {

-        /* Invoke the expire callback and don't send prompter warnings. */

-        (*expire_cb)(context, expire_data, pw_exp, acct_exp, is_last_req);

-        return;

-    }

-

-    /* Don't warn if no password expiry value was sent. */

-    if (pw_exp == 0)

-        return;

-

-    /* Don't warn if the password is being changed. */

-    if (in_tkt_service && strcmp(in_tkt_service, "kadmin/changepw") == 0)

-        return;

-

-    /*

-     * If the expiry time came from a last_req field, assume the KDC wants us

-     * to warn.  Otherwise, warn only if the expiry time is less than a week

-     * from now.

-     */

-    ret = krb5_timeofday(context, &now;;

-    if (ret != 0)

-        return;

-    if (!is_last_req &&

-        (ts_after(now, pw_exp) || ts_delta(pw_exp, now) > 7 * 24 * 60 * 60))

-        return;

-

-    if (!prompter)

-        return;

-

-    ret = krb5_timestamp_to_string(pw_exp, ts, sizeof(ts));

-    if (ret != 0)

-        return;

-

-    delta = ts_delta(pw_exp, now);

-    if (delta < 3600) {

-        snprintf(banner, sizeof(banner),

-                 _("Warning: Your password will expire in less than one hour "

-                   "on %s"), ts);

-    } else if (delta < 86400*2) {

-        snprintf(banner, sizeof(banner),

-                 _("Warning: Your password will expire in %d hour%s on %s"),

-                 delta / 3600, delta < 7200 ? "" : "s", ts);

-    } else {

-        snprintf(banner, sizeof(banner),

-                 _("Warning: Your password will expire in %d days on %s"),

-                 delta / 86400, ts);

-    }

-

-    /* PROMPTER_INVOCATION */

-    (*prompter)(context, data, 0, banner, 0, 0);

-}

-

 /*

  * Create a temporary options structure for getting a kadmin/changepw ticket,

  * based on the appplication-specified options.  Propagate all application

@@ -496,9 +389,6 @@ krb5_get_init_creds_password(krb5_context context,

         goto cleanup;

 cleanup:

-    if (ret == 0)

-        warn_pw_expiry(context, options, prompter, data, in_tkt_service,

-                       as_reply);

     free(chpw_opts);

     zapfree(gakpw.storage.data, gakpw.storage.length);

     memset(pw0array, 0, sizeof(pw0array));

diff --git a/src/lib/krb5/krb/t_expire_warn.c b/src/lib/krb5/krb/t_expire_warn.c

index 1e59acba1..dc8dc8fb3 100644

--- a/src/lib/krb5/krb/t_expire_warn.c

+++ b/src/lib/krb5/krb/t_expire_warn.c

@@ -28,6 +28,13 @@

 static int exp_dummy, prompt_dummy;

+static void

+check(krb5_error_code code)

+{

+    if (code != 0)

+        abort();

+}

+

 static krb5_error_code

 prompter_cb(krb5_context ctx, void *data, const char *name,

             const char *banner, int num_prompts, krb5_prompt prompts[])

@@ -52,36 +59,48 @@ int

 main(int argc, char **argv)

 {

     krb5_context ctx;

+    krb5_init_creds_context icctx;

     krb5_get_init_creds_opt *opt;

     char *user, *password, *service = NULL;

-    krb5_boolean use_cb;

+    krb5_boolean use_cb, stepwise;

     krb5_principal client;

     krb5_creds creds;

-    if (argc < 4) {

-        fprintf(stderr, "Usage: %s username password {1|0} [service]\n",

+    if (argc < 5) {

+        fprintf(stderr, "Usage: %s username password {1|0} {1|0} [service]\n",

                 argv[0]);

         return 1;

     }

     user = argv[1];

     password = argv[2];

     use_cb = atoi(argv[3]);

-    if (argc >= 5)

-        service = argv[4];

+    stepwise = atoi(argv[4]);

+    if (argc >= 6)

+        service = argv[5];

-    assert(krb5_init_context(&ctx) == 0);

-    assert(krb5_get_init_creds_opt_alloc(ctx, &opt) == 0);

+    check(krb5_init_context(&ctx));

+    check(krb5_get_init_creds_opt_alloc(ctx, &opt));

     if (use_cb) {

-        assert(krb5_get_init_creds_opt_set_expire_callback(ctx, opt, expire_cb,

-                                                           &exp_dummy) == 0);

+        check(krb5_get_init_creds_opt_set_expire_callback(ctx, opt, expire_cb,

+                                                          &exp_dummy));

+    }

+    check(krb5_parse_name(ctx, user, &client));

+    if (stepwise) {

+        check(krb5_init_creds_init(ctx, client, prompter_cb, &prompt_dummy, 0,

+                                   opt, &icctx));

+        krb5_init_creds_set_password(ctx, icctx, password);

+        if (service != NULL)

+            check(krb5_init_creds_set_service(ctx, icctx, service));

+        check(krb5_init_creds_get(ctx, icctx));

+        krb5_init_creds_free(ctx, icctx);

+    } else {

+        check(krb5_get_init_creds_password(ctx, &creds, client, password,

+                                           prompter_cb, &prompt_dummy, 0,

+                                           service, opt));

+        krb5_free_cred_contents(ctx, &creds);

     }

-    assert(krb5_parse_name(ctx, user, &client) == 0);

-    assert(krb5_get_init_creds_password(ctx, &creds, client, password,

-                                        prompter_cb, &prompt_dummy, 0, service,

-                                        opt) == 0);

     krb5_get_init_creds_opt_free(ctx, opt);

     krb5_free_principal(ctx, client);

-    krb5_free_cred_contents(ctx, &creds);

     krb5_free_context(ctx);

     return 0;

 }

diff --git a/src/lib/krb5/krb/t_expire_warn.py b/src/lib/krb5/krb/t_expire_warn.py

index 781f2728a..e163cc7e4 100755

--- a/src/lib/krb5/krb/t_expire_warn.py

+++ b/src/lib/krb5/krb/t_expire_warn.py

@@ -34,23 +34,33 @@ realm.run([kadminl, 'addprinc', '-pw', 'pass', '-pwexpire', '12 hours',

 realm.run([kadminl, 'addprinc', '-pw', 'pass', '-pwexpire', '3 days', 'days'])

 # Check for expected prompter warnings when no expire callback is used.

-output = realm.run(['./t_expire_warn', 'noexpire', 'pass', '0'])

+output = realm.run(['./t_expire_warn', 'noexpire', 'pass', '0', '0'])

 if output:

     fail('Unexpected output for noexpire')

-realm.run(['./t_expire_warn', 'minutes', 'pass', '0'],

+realm.run(['./t_expire_warn', 'minutes', 'pass', '0', '0'],

           expected_msg=' less than one hour on ')

-realm.run(['./t_expire_warn', 'hours', 'pass', '0'], expected_msg=' hours on ')

-realm.run(['./t_expire_warn', 'days', 'pass', '0'], expected_msg=' days on ')

+realm.run(['./t_expire_warn', 'hours', 'pass', '0', '0'],

+          expected_msg=' hours on ')

+realm.run(['./t_expire_warn', 'days', 'pass', '0', '0'],

+          expected_msg=' days on ')

+# Try one case with the stepwise interface.

+realm.run(['./t_expire_warn', 'days', 'pass', '0', '1'],

+          expected_msg=' days on ')

 # Check for expected expire callback behavior.  These tests are

 # carefully agnostic about whether the KDC supports last_req fields,

 # and could be made more specific if last_req support is added.

-output = realm.run(['./t_expire_warn', 'noexpire', 'pass', '1'])

+output = realm.run(['./t_expire_warn', 'noexpire', 'pass', '1', '0'])

 if 'password_expiration = 0\n' not in output or \

         'account_expiration = 0\n' not in output or \

         'is_last_req = ' not in output:

     fail('Expected callback output not seen for noexpire')

-output = realm.run(['./t_expire_warn', 'days', 'pass', '1'])

+output = realm.run(['./t_expire_warn', 'days', 'pass', '1', '0'])

+if 'password_expiration = ' not in output or \

+        'password_expiration = 0\n' in output:

+    fail('Expected non-zero password expiration not seen for days')

+# Try one case with the stepwise interface.

+output = realm.run(['./t_expire_warn', 'days', 'pass', '1', '1'])

 if 'password_expiration = ' not in output or \

         'password_expiration = 0\n' in output:

     fail('Expected non-zero password expiration not seen for days')