gss: implement gss_krb5_ccache_name()

Correctly implement gss_krb5_ccache_name() in terms of
gss_set_sec_context_option(GSS_KRB5_CCACHE_NAME_X). The previous implementation
was a NOOP.

Note: global ccache name should really be thread-specific rather than global.

Closes #803.

lib/gssapi/krb5/ccache_name.c

@@ -33,7 +33,7 @@
 
 #include "gsskrb5_locl.h"
 
-char *last_out_name;
+static heim_base_atomic(char *) last_out_name; /* XXX should be thread-specific */
 
 OM_uint32
 _gsskrb5_krb5_ccache_name(OM_uint32 *minor_status,
@@ -48,25 +48,26 @@ _gsskrb5_krb5_ccache_name(OM_uint32 *minor_status,
     GSSAPI_KRB5_INIT(&context);
 
     if (out_name) {
-	const char *n;
+	const char *def_name;
 
-	if (last_out_name) {
+	*out_name = NULL;
-	    free(last_out_name);
+
-	    last_out_name = NULL;
+	def_name = krb5_cc_default_name(context);
-	}
+	if (def_name) {
+	    char *s = strdup(def_name);
+	    if (s) {
+		s = heim_base_exchange_pointer(&last_out_name, s);
+		free(s);
 
-	n = krb5_cc_default_name(context);
-	if (n == NULL) {
-	    *minor_status = ENOMEM;
-	    return GSS_S_FAILURE;
-	}
-	last_out_name = strdup(n);
-	if (last_out_name == NULL) {
-	    *minor_status = ENOMEM;
-	    return GSS_S_FAILURE;
-	}
 		*out_name = last_out_name;
 	    }
+	}
+
+	if (*out_name == NULL) {
+	    *minor_status = ENOMEM;
+	    return GSS_S_FAILURE;
+	}
+    }
 
     kret = krb5_cc_set_default_name(context, name);
     if (kret) {

lib/gssapi/krb5/gsskrb5_locl.h

@@ -145,4 +145,9 @@ extern HEIMDAL_MUTEX gssapi_keytab_mutex;
 #define SC_ORDER          0x0080
 #define SC_AUTHENTICATOR  0x0100
 
+struct gsskrb5_ccache_name_args {
+    const char *name;
+    const char *out_name;
+};
+
 #endif

lib/gssapi/krb5/set_sec_context_option.c

@@ -294,23 +294,6 @@ _gsskrb5_set_sec_context_option
 	*minor_status = EINVAL;
 	return GSS_S_FAILURE;
 
-    } else if (gss_oid_equal(desired_object, GSS_KRB5_CCACHE_NAME_X)) {
-	char *str;
-
-	maj_stat = get_string(minor_status, value, &str);
-	if (maj_stat != GSS_S_COMPLETE)
-	    return maj_stat;
-	if (str == NULL) {
-	    *minor_status = 0;
-	    return GSS_S_CALL_INACCESSIBLE_READ;
-	}
-
-	*minor_status = krb5_cc_set_default_name(context, str);
-	free(str);
-	if (*minor_status)
-	    return GSS_S_FAILURE;
-
-	return GSS_S_COMPLETE;
     } else if (gss_oid_equal(desired_object, GSS_KRB5_SET_TIME_OFFSET_X)) {
 	OM_uint32 offset;
 	time_t t;
@@ -352,6 +335,15 @@ _gsskrb5_set_sec_context_option
 
 	*minor_status = 0;
 	return GSS_S_COMPLETE;
+    } else if (gss_oid_equal(desired_object, GSS_KRB5_CCACHE_NAME_X)) {
+	struct gsskrb5_ccache_name_args *args = value->value;
+
+	if (value->length != sizeof(*args)) {
+	    *minor_status = EINVAL;
+	    return GSS_S_FAILURE;
+	}
+
+	return _gsskrb5_krb5_ccache_name(minor_status, args->name, &args->out_name);
     } else if (gss_oid_equal(desired_object, GSS_KRB5_IMPORT_RFC4121_CONTEXT_X)) {
 	return make_rfc4121_context(minor_status, context, context_handle, value);
     }

lib/gssapi/mech/gss_krb5.c

@@ -487,26 +487,42 @@ gss_krb5_ccache_name(OM_uint32 *minor_status,
 {
     struct _gss_mech_switch *m;
     gss_buffer_desc buffer = GSS_C_EMPTY_BUFFER;
-    OM_uint32 junk;
+    OM_uint32 major_status;
+    struct gsskrb5_ccache_name_args args;
 
     _gss_load_mech();
 
+    *minor_status = 0;
+
     if (out_name)
 	*out_name = NULL;
 
-    buffer.value = rk_UNCONST(name);
+    args.name = name;
-    if (name) {
+    args.out_name = NULL;
-	buffer.length = strlen(name);
+
-    }
+    buffer.value = &args;
+    buffer.length = sizeof(args);
+
+    major_status = GSS_S_UNAVAILABLE;
 
     HEIM_TAILQ_FOREACH(m, &_gss_mechs, gm_link) {
+	OM_uint32 mech_major, mech_minor;
+
 	if (m->gm_mech.gm_set_sec_context_option == NULL)
 	    continue;
-	m->gm_mech.gm_set_sec_context_option(&junk, NULL,
+
-	    GSS_KRB5_CCACHE_NAME_X, &buffer);
+	mech_major = m->gm_mech.gm_set_sec_context_option(&mech_minor,
+	    NULL, GSS_KRB5_CCACHE_NAME_X, &buffer);
+	if (mech_major != GSS_S_UNAVAILABLE) {
+	    major_status = mech_major;
+	    *minor_status = mech_minor;
+	    break;
+	}
     }
 
-    return (GSS_S_COMPLETE);
+    *out_name = args.out_name;
+
+    return major_status;
 }