diff -up openssh-8.6p1/auth.h.ccache_name openssh-8.6p1/auth.h

--- openssh-8.6p1/auth.h.ccache_name	2021-04-19 14:05:10.820744325 +0200

+++ openssh-8.6p1/auth.h	2021-04-19 14:05:10.853744569 +0200

@@ -83,6 +83,7 @@ struct Authctxt {

 	krb5_principal	 krb5_user;

 	char		*krb5_ticket_file;

 	char		*krb5_ccname;

+	int		 krb5_set_env;

 #endif

 	struct sshbuf	*loginmsg;

@@ -231,7 +232,7 @@ struct passwd *fakepw(void);

 int	 sys_auth_passwd(struct ssh *, const char *);

 #if defined(KRB5) && !defined(HEIMDAL)

-krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);

+krb5_error_code ssh_krb5_cc_new_unique(krb5_context, krb5_ccache *, int *);

 #endif

 #endif /* AUTH_H */

diff -up openssh-8.6p1/auth-krb5.c.ccache_name openssh-8.6p1/auth-krb5.c

--- openssh-8.6p1/auth-krb5.c.ccache_name	2021-04-16 05:55:25.000000000 +0200

+++ openssh-8.6p1/auth-krb5.c	2021-04-19 14:40:55.142832954 +0200

@@ -51,6 +51,7 @@

 #include <unistd.h>

 #include <string.h>

 #include <krb5.h>

+#include <profile.h>

 extern ServerOptions	 options;

@@ -77,7 +78,7 @@ auth_krb5_password(Authctxt *authctxt, c

 #endif

 	krb5_error_code problem;

 	krb5_ccache ccache = NULL;

-	int len;

+	char *ticket_name = NULL;

 	char *client, *platform_client;

 	const char *errmsg;

@@ -163,8 +164,8 @@ auth_krb5_password(Authctxt *authctxt, c

 		goto out;

 	}

-	problem = ssh_krb5_cc_gen(authctxt->krb5_ctx,

-	    &authctxt->krb5_fwd_ccache);

+	problem = ssh_krb5_cc_new_unique(authctxt->krb5_ctx,

+	     &authctxt->krb5_fwd_ccache, &authctxt->krb5_set_env);

 	if (problem)

 		goto out;

@@ -179,15 +180,14 @@ auth_krb5_password(Authctxt *authctxt, c

 		goto out;

 #endif

-	authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);

+	problem = krb5_cc_get_full_name(authctxt->krb5_ctx,

+	    authctxt->krb5_fwd_ccache, &ticket_name);

-	len = strlen(authctxt->krb5_ticket_file) + 6;

-	authctxt->krb5_ccname = xmalloc(len);

-	snprintf(authctxt->krb5_ccname, len, "FILE:%s",

-	    authctxt->krb5_ticket_file);

+	authctxt->krb5_ccname = xstrdup(ticket_name);

+	krb5_free_string(authctxt->krb5_ctx, ticket_name);

 #ifdef USE_PAM

-	if (options.use_pam)

+	if (options.use_pam && authctxt->krb5_set_env)

 		do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname);

 #endif

@@ -223,11 +223,54 @@ auth_krb5_password(Authctxt *authctxt, c

 void

 krb5_cleanup_proc(Authctxt *authctxt)

 {

+	struct stat krb5_ccname_stat;

+	char krb5_ccname[128], *krb5_ccname_dir_start, *krb5_ccname_dir_end;

+

 	debug("krb5_cleanup_proc called");

 	if (authctxt->krb5_fwd_ccache) {

-		krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);

+		krb5_context ctx = authctxt->krb5_ctx;

+		krb5_cccol_cursor cursor;

+		krb5_ccache ccache;

+		int ret;

+

+		krb5_cc_destroy(ctx, authctxt->krb5_fwd_ccache);

 		authctxt->krb5_fwd_ccache = NULL;

+

+		ret = krb5_cccol_cursor_new(ctx, &cursor);

+		if (ret)

+			goto out;

+

+		ret = krb5_cccol_cursor_next(ctx, cursor, &ccache);

+		if (ret == 0 && ccache != NULL) {

+			/* There is at least one other ccache in collection

+			 * we can switch to */

+			krb5_cc_switch(ctx, ccache);

+		} else if (authctxt->krb5_ccname != NULL) {

+			/* Clean up the collection too */

+			strncpy(krb5_ccname, authctxt->krb5_ccname, sizeof(krb5_ccname) - 10);

+			krb5_ccname_dir_start = strchr(krb5_ccname, ':') + 1;

+			*krb5_ccname_dir_start++ = '\0';

+			if (strcmp(krb5_ccname, "DIR") == 0) {

+

+				strcat(krb5_ccname_dir_start, "/primary");

+

+				if (stat(krb5_ccname_dir_start, &krb5_ccname_stat) == 0) {

+					if (unlink(krb5_ccname_dir_start) == 0) {

+						krb5_ccname_dir_end = strrchr(krb5_ccname_dir_start, '/');

+						*krb5_ccname_dir_end = '\0';

+						if (rmdir(krb5_ccname_dir_start) == -1)

+							debug("cache dir '%s' remove failed: %s",

+							    krb5_ccname_dir_start, strerror(errno));

+					}

+					else

+						debug("cache primary file '%s', remove failed: %s",

+						    krb5_ccname_dir_start, strerror(errno));

+				}

+			}

+		}

+		krb5_cccol_cursor_free(ctx, &cursor);

 	}

+out:

 	if (authctxt->krb5_user) {

 		krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);

 		authctxt->krb5_user = NULL;

@@ -238,36 +281,188 @@ krb5_cleanup_proc(Authctxt *authctxt)

 	}

 }

-#ifndef HEIMDAL

+

+#if !defined(HEIMDAL)

+int

+ssh_asprintf_append(char **dsc, const char *fmt, ...) {

+	char *src, *old;

+	va_list ap;

+	int i;

+

+	va_start(ap, fmt);

+	i = vasprintf(&src, fmt, ap);

+	va_end(ap);

+

+	if (i == -1 || src == NULL)

+		return -1;

+

+	old = *dsc;

+

+	i = asprintf(dsc, "%s%s", *dsc, src);

+	if (i == -1 || src == NULL) {

+		free(src);

+		return -1;

+	}

+

+	free(old);

+	free(src);

+

+	return i;

+}

+

+int

+ssh_krb5_expand_template(char **result, const char *template) {

+	char *p_n, *p_o, *r, *tmp_template;

+

+	debug3_f("called, template = %s", template);

+	if (template == NULL)

+		return -1;

+

+	tmp_template = p_n = p_o = xstrdup(template);

+	r = xstrdup("");

+

+	while ((p_n = strstr(p_o, "%{")) != NULL) {

+

+		*p_n++ = '\0';

+		if (ssh_asprintf_append(&r, "%s", p_o) == -1)

+			goto cleanup;

+

+		if (strncmp(p_n, "{uid}", 5) == 0 || strncmp(p_n, "{euid}", 6) == 0 ||

+			strncmp(p_n, "{USERID}", 8) == 0) {

+			p_o = strchr(p_n, '}') + 1;

+			if (ssh_asprintf_append(&r, "%d", geteuid()) == -1)

+				goto cleanup;

+			continue;

+		}

+		else if (strncmp(p_n, "{TEMP}", 6) == 0) {

+			p_o = strchr(p_n, '}') + 1;

+			if (ssh_asprintf_append(&r, "/tmp") == -1)

+				goto cleanup;

+			continue;

+		} else {

+			p_o = strchr(p_n, '}') + 1;

+			*p_o = '\0';

+			debug_f("unsupported token %s in %s", p_n, template);

+			/* unknown token, fallback to the default */

+			goto cleanup;

+		}

+	}

+

+	if (ssh_asprintf_append(&r, "%s", p_o) == -1)

+		goto cleanup;

+

+	*result = r;

+	free(tmp_template);

+	return 0;

+

+cleanup:

+	free(r);

+	free(tmp_template);

+	return -1;

+}

+

+krb5_error_code

+ssh_krb5_get_cctemplate(krb5_context ctx, char **ccname) {

+	profile_t p;

+	int ret = 0;

+	char *value = NULL;

+

+	debug3_f("called");

+	ret = krb5_get_profile(ctx, &p);

+	if (ret)

+		return ret;

+

+	ret = profile_get_string(p, "libdefaults", "default_ccache_name", NULL, NULL, &value);

+	if (ret || !value)

+		return ret;

+

+	ret = ssh_krb5_expand_template(ccname, value);

+

+	debug3_f("returning with ccname = %s", *ccname);

+	return ret;

+}

+

 krb5_error_code

-ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {

-	int tmpfd, ret, oerrno;

-	char ccname[40];

+ssh_krb5_cc_new_unique(krb5_context ctx, krb5_ccache *ccache, int *need_environment) {

+	int tmpfd, ret, oerrno, type_len;

+	char *ccname = NULL;

 	mode_t old_umask;

+	char *type = NULL, *colon = NULL;

-	ret = snprintf(ccname, sizeof(ccname),

-	    "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());

-	if (ret < 0 || (size_t)ret >= sizeof(ccname))

-		return ENOMEM;

-

-	old_umask = umask(0177);

-	tmpfd = mkstemp(ccname + strlen("FILE:"));

-	oerrno = errno;

-	umask(old_umask);

-	if (tmpfd == -1) {

-		logit("mkstemp(): %.100s", strerror(oerrno));

-		return oerrno;

-	}

+	debug3_f("called");

+	if (need_environment)

+		*need_environment = 0;

+	ret = ssh_krb5_get_cctemplate(ctx, &ccname);

+	if (ret || !ccname || options.kerberos_unique_ccache) {

+		/* Otherwise, go with the old method */

+		if (ccname)

+			free(ccname);

+		ccname = NULL;

+

+		ret = asprintf(&ccname,

+		    "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());

+		if (ret < 0)

+			return ENOMEM;

-	if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {

+		old_umask = umask(0177);

+		tmpfd = mkstemp(ccname + strlen("FILE:"));

 		oerrno = errno;

-		logit("fchmod(): %.100s", strerror(oerrno));

+		umask(old_umask);

+		if (tmpfd == -1) {

+			logit("mkstemp(): %.100s", strerror(oerrno));

+			return oerrno;

+		}

+

+		if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {

+			oerrno = errno;

+			logit("fchmod(): %.100s", strerror(oerrno));

+			close(tmpfd);

+			return oerrno;

+		}

+		/* make sure the KRB5CCNAME is set for non-standard location */

+		if (need_environment)

+			*need_environment = 1;

 		close(tmpfd);

-		return oerrno;

 	}

-	close(tmpfd);

-	return (krb5_cc_resolve(ctx, ccname, ccache));

+	debug3_f("setting default ccname to %s", ccname);

+	/* set the default with already expanded user IDs */

+	ret = krb5_cc_set_default_name(ctx, ccname);

+	if (ret)

+		return ret;

+

+	if ((colon = strstr(ccname, ":")) != NULL) {

+		type_len = colon - ccname;

+		type = malloc((type_len + 1) * sizeof(char));

+		if (type == NULL)

+			return ENOMEM;

+		strncpy(type, ccname, type_len);

+		type[type_len] = 0;

+	} else {

+		type = strdup(ccname);

+	}

+

+	/* If we have a credential cache from krb5.conf, we need to switch

+	 * a primary cache for this collection, if it supports that (non-FILE)

+	 */

+	if (krb5_cc_support_switch(ctx, type)) {

+		debug3_f("calling cc_new_unique(%s)", ccname);

+		ret = krb5_cc_new_unique(ctx, type, NULL, ccache);

+		free(type);

+		if (ret)

+			return ret;

+

+		debug3_f("calling cc_switch()");

+		return krb5_cc_switch(ctx, *ccache);

+	} else {

+		/* Otherwise, we can not create a unique ccname here (either

+		 * it is already unique from above or the type does not support

+		 * collections

+		 */

+		free(type);

+		debug3_f("calling cc_resolve(%s)", ccname);

+		return (krb5_cc_resolve(ctx, ccname, ccache));

+	}

 }

 #endif /* !HEIMDAL */

 #endif /* KRB5 */

diff -up openssh-8.6p1/gss-serv.c.ccache_name openssh-8.6p1/gss-serv.c

--- openssh-8.6p1/gss-serv.c.ccache_name	2021-04-19 14:05:10.844744503 +0200

+++ openssh-8.6p1/gss-serv.c	2021-04-19 14:05:10.854744577 +0200

@@ -413,13 +413,15 @@ ssh_gssapi_cleanup_creds(void)

 }

 /* As user */

-void

+int

 ssh_gssapi_storecreds(void)

 {

 	if (gssapi_client.mech && gssapi_client.mech->storecreds) {

-		(*gssapi_client.mech->storecreds)(&gssapi_client);

+		return (*gssapi_client.mech->storecreds)(&gssapi_client);

 	} else

 		debug("ssh_gssapi_storecreds: Not a GSSAPI mechanism");

+

+	return 0;

 }

 /* This allows GSSAPI methods to do things to the child's environment based

@@ -499,9 +501,7 @@ ssh_gssapi_rekey_creds(void) {

 	char *envstr;

 #endif

-	if (gssapi_client.store.filename == NULL &&

-	    gssapi_client.store.envval == NULL &&

-	    gssapi_client.store.envvar == NULL)

+	if (gssapi_client.store.envval == NULL)

 		return;

 	ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));

diff -up openssh-8.6p1/gss-serv-krb5.c.ccache_name openssh-8.6p1/gss-serv-krb5.c

--- openssh-8.6p1/gss-serv-krb5.c.ccache_name	2021-04-19 14:05:10.852744562 +0200

+++ openssh-8.6p1/gss-serv-krb5.c	2021-04-19 14:05:10.854744577 +0200

@@ -267,7 +267,7 @@ ssh_gssapi_krb5_cmdok(krb5_principal pri

 /* This writes out any forwarded credentials from the structure populated

  * during userauth. Called after we have setuid to the user */

-static void

+static int

 ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)

 {

 	krb5_ccache ccache;

@@ -276,14 +276,15 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl

 	OM_uint32 maj_status, min_status;

 	const char *new_ccname, *new_cctype;

 	const char *errmsg;

+	int set_env = 0;

 	if (client->creds == NULL) {

 		debug("No credentials stored");

-		return;

+		return 0;

 	}

 	if (ssh_gssapi_krb5_init() == 0)

-		return;

+		return 0;

 #ifdef HEIMDAL

 # ifdef HAVE_KRB5_CC_NEW_UNIQUE

@@ -297,14 +298,14 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl

 		krb5_get_err_text(krb_context, problem));

 # endif

 		krb5_free_error_message(krb_context, errmsg);

-		return;

+		return 0;

 	}

 #else

-	if ((problem = ssh_krb5_cc_gen(krb_context, &ccache))) {

+	if ((problem = ssh_krb5_cc_new_unique(krb_context, &ccache, &set_env)) != 0) {

 		errmsg = krb5_get_error_message(krb_context, problem);

-		logit("ssh_krb5_cc_gen(): %.100s", errmsg);

+		logit("ssh_krb5_cc_new_unique(): %.100s", errmsg);

 		krb5_free_error_message(krb_context, errmsg);

-		return;

+		return 0;

 	}

 #endif	/* #ifdef HEIMDAL */

@@ -313,7 +314,7 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl

 		errmsg = krb5_get_error_message(krb_context, problem);

 		logit("krb5_parse_name(): %.100s", errmsg);

 		krb5_free_error_message(krb_context, errmsg);

-		return;

+		return 0;

 	}

 	if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) {

@@ -322,7 +323,7 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl

 		krb5_free_error_message(krb_context, errmsg);

 		krb5_free_principal(krb_context, princ);

 		krb5_cc_destroy(krb_context, ccache);

-		return;

+		return 0;

 	}

 	krb5_free_principal(krb_context, princ);

@@ -331,32 +332,21 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl

 	    client->creds, ccache))) {

 		logit("gss_krb5_copy_ccache() failed");

 		krb5_cc_destroy(krb_context, ccache);

-		return;

+		return 0;

 	}

 	new_cctype = krb5_cc_get_type(krb_context, ccache);

 	new_ccname = krb5_cc_get_name(krb_context, ccache);

-

-	client->store.envvar = "KRB5CCNAME";

-#ifdef USE_CCAPI

-	xasprintf(&client->store.envval, "API:%s", new_ccname);

-	client->store.filename = NULL;

-#else

-	if (new_ccname[0] == ':')

-		new_ccname++;

 	xasprintf(&client->store.envval, "%s:%s", new_cctype, new_ccname);

-	if (strcmp(new_cctype, "DIR") == 0) {

-		char *p;

-		p = strrchr(client->store.envval, '/');

-		if (p)

-			*p = '\0';

+

+	if (set_env) {

+		client->store.envvar = "KRB5CCNAME";

 	}

 	if ((strcmp(new_cctype, "FILE") == 0) || (strcmp(new_cctype, "DIR") == 0))

 		client->store.filename = xstrdup(new_ccname);

-#endif

 #ifdef USE_PAM

-	if (options.use_pam)

+	if (options.use_pam && set_env)

 		do_pam_putenv(client->store.envvar, client->store.envval);

 #endif

@@ -364,7 +354,7 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl

 	client->store.data = krb_context;

-	return;

+	return set_env;

 }

 int

diff -up openssh-8.6p1/servconf.c.ccache_name openssh-8.6p1/servconf.c

--- openssh-8.6p1/servconf.c.ccache_name	2021-04-19 14:05:10.848744532 +0200

+++ openssh-8.6p1/servconf.c	2021-04-19 14:05:10.854744577 +0200

@@ -136,6 +136,7 @@ initialize_server_options(ServerOptions

 	options->kerberos_or_local_passwd = -1;

 	options->kerberos_ticket_cleanup = -1;

 	options->kerberos_get_afs_token = -1;

+	options->kerberos_unique_ccache = -1;

 	options->gss_authentication=-1;

 	options->gss_keyex = -1;

 	options->gss_cleanup_creds = -1;

@@ -359,6 +360,8 @@ fill_default_server_options(ServerOption

 		options->kerberos_ticket_cleanup = 1;

 	if (options->kerberos_get_afs_token == -1)

 		options->kerberos_get_afs_token = 0;

+	if (options->kerberos_unique_ccache == -1)

+		options->kerberos_unique_ccache = 0;

 	if (options->gss_authentication == -1)

 		options->gss_authentication = 0;

 	if (options->gss_keyex == -1)

@@ -506,7 +509,7 @@ typedef enum {

	sPort, sHostKeyFile, sLoginGraceTime,

	sPermitRootLogin, sLogFacility, sLogLevel, sLogVerbose,

	sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,

-	sKerberosGetAFSToken, sPasswordAuthentication,

+	sKerberosGetAFSToken, sKerberosUniqueCCache, sPasswordAuthentication,

	sKbdInteractiveAuthentication, sListenAddress, sAddressFamily,

	sPrintMotd, sPrintLastLog, sIgnoreRhosts,

	sX11Forwarding, sX11DisplayOffset, sX11UseLocalhost,

@@ -593,11 +597,13 @@ static struct {

 #else

 	{ "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL },

 #endif

+	{ "kerberosuniqueccache", sKerberosUniqueCCache, SSHCFG_GLOBAL },

 #else

 	{ "kerberosauthentication", sUnsupported, SSHCFG_ALL },

 	{ "kerberosorlocalpasswd", sUnsupported, SSHCFG_GLOBAL },

 	{ "kerberosticketcleanup", sUnsupported, SSHCFG_GLOBAL },

 	{ "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL },

+	{ "kerberosuniqueccache", sUnsupported, SSHCFG_GLOBAL },

 #endif

 	{ "kerberostgtpassing", sUnsupported, SSHCFG_GLOBAL },

 	{ "afstokenpassing", sUnsupported, SSHCFG_GLOBAL },

@@ -1573,6 +1579,10 @@ process_server_config_line_depth(ServerO

 		intptr = &options->kerberos_get_afs_token;

 		goto parse_flag;

+	case sKerberosUniqueCCache:

+		intptr = &options->kerberos_unique_ccache;

+		goto parse_flag;

+

 	case sGssAuthentication:

 		intptr = &options->gss_authentication;

 		goto parse_flag;

@@ -2891,6 +2901,7 @@ dump_config(ServerOptions *o)

 # ifdef USE_AFS

 	dump_cfg_fmtint(sKerberosGetAFSToken, o->kerberos_get_afs_token);

 # endif

+	dump_cfg_fmtint(sKerberosUniqueCCache, o->kerberos_unique_ccache);

 #endif

 #ifdef GSSAPI

 	dump_cfg_fmtint(sGssAuthentication, o->gss_authentication);

diff -up openssh-8.6p1/servconf.h.ccache_name openssh-8.6p1/servconf.h

--- openssh-8.6p1/servconf.h.ccache_name	2021-04-19 14:05:10.848744532 +0200

+++ openssh-8.6p1/servconf.h	2021-04-19 14:05:10.855744584 +0200

@@ -140,6 +140,8 @@ typedef struct {

 						 * file on logout. */

 	int     kerberos_get_afs_token;		/* If true, try to get AFS token if

 						 * authenticated with Kerberos. */

+	int     kerberos_unique_ccache;		/* If true, the acquired ticket will

+						 * be stored in per-session ccache */

 	int     gss_authentication;	/* If true, permit GSSAPI authentication */

 	int     gss_keyex;		/* If true, permit GSSAPI key exchange */

 	int     gss_cleanup_creds;	/* If true, destroy cred cache on logout */

diff -up openssh-8.6p1/session.c.ccache_name openssh-8.6p1/session.c

--- openssh-8.6p1/session.c.ccache_name	2021-04-19 14:05:10.852744562 +0200

+++ openssh-8.6p1/session.c	2021-04-19 14:05:10.855744584 +0200

@@ -1038,7 +1038,8 @@ do_setup_env(struct ssh *ssh, Session *s

 	/* Allow any GSSAPI methods that we've used to alter

 	 * the child's environment as they see fit

 	 */

-	ssh_gssapi_do_child(&env, &envsize);

+	if (s->authctxt->krb5_set_env)

+		ssh_gssapi_do_child(&env, &envsize);

 #endif

 	/* Set basic environment. */

@@ -1114,7 +1115,7 @@ do_setup_env(struct ssh *ssh, Session *s

 	}

 #endif

 #ifdef KRB5

-	if (s->authctxt->krb5_ccname)

+	if (s->authctxt->krb5_ccname && s->authctxt->krb5_set_env)

 		child_set_env(&env, &envsize, "KRB5CCNAME",

 		    s->authctxt->krb5_ccname);

 #endif

diff -up openssh-8.6p1/sshd.c.ccache_name openssh-8.6p1/sshd.c

--- openssh-8.6p1/sshd.c.ccache_name	2021-04-19 14:05:10.849744540 +0200

+++ openssh-8.6p1/sshd.c	2021-04-19 14:05:10.855744584 +0200

@@ -2284,7 +2284,7 @@ main(int ac, char **av)

 #ifdef GSSAPI

 	if (options.gss_authentication) {

 		temporarily_use_uid(authctxt->pw);

-		ssh_gssapi_storecreds();

+		authctxt->krb5_set_env = ssh_gssapi_storecreds();

 		restore_uid();

 	}

 #endif

diff -up openssh-8.6p1/sshd_config.5.ccache_name openssh-8.6p1/sshd_config.5

--- openssh-8.6p1/sshd_config.5.ccache_name	2021-04-19 14:05:10.849744540 +0200

+++ openssh-8.6p1/sshd_config.5	2021-04-19 14:05:10.856744592 +0200

@@ -939,6 +939,14 @@ Specifies whether to automatically destr

 file on logout.

 The default is

 .Cm yes .

+.It Cm KerberosUniqueCCache

+Specifies whether to store the acquired tickets in the per-session credential

+cache under /tmp/ or whether to use per-user credential cache as configured in

+.Pa /etc/krb5.conf .

+The default value

+.Cm no

+can lead to overwriting previous tickets by subseqent connections to the same

+user account.

 .It Cm KexAlgorithms

 Specifies the available KEX (Key Exchange) algorithms.

 Multiple algorithms must be comma-separated.

diff -up openssh-8.6p1/ssh-gss.h.ccache_name openssh-8.6p1/ssh-gss.h

--- openssh-8.6p1/ssh-gss.h.ccache_name	2021-04-19 14:05:10.852744562 +0200

+++ openssh-8.6p1/ssh-gss.h	2021-04-19 14:05:10.855744584 +0200

@@ -114,7 +114,7 @@ typedef struct ssh_gssapi_mech_struct {

 	int (*dochild) (ssh_gssapi_client *);

 	int (*userok) (ssh_gssapi_client *, char *);

 	int (*localname) (ssh_gssapi_client *, char **);

-	void (*storecreds) (ssh_gssapi_client *);

+	int (*storecreds) (ssh_gssapi_client *);

 	int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *);

 } ssh_gssapi_mech;

@@ -175,7 +175,7 @@ int ssh_gssapi_userok(char *name, struct

 OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);

 void ssh_gssapi_do_child(char ***, u_int *);

 void ssh_gssapi_cleanup_creds(void);

-void ssh_gssapi_storecreds(void);

+int ssh_gssapi_storecreds(void);

 const char *ssh_gssapi_displayname(void);

 char *ssh_gssapi_server_mechanisms(void);