From 3d11179707923b033fa413387a33296b673ff52d Mon Sep 17 00:00:00 2001
From: Robbie Harwood <rharwood@redhat.com>
Date: Thu, 14 Jan 2021 18:13:09 -0500
Subject: [PATCH] Add APIs for marshalling credentials
Faciliate KCM daemon implementations by providing functions to
deserialize and reserialize credentials in the FILE v4 format.
[ghudson@mit.edu: minor editorial changes]
ticket: 8980 (new)
(cherry picked from commit 18ea3bd2fca55b789b7de9c663624bc11d348fa6)
---
doc/appdev/refs/api/index.rst | 2 ++
src/include/krb5/krb5.hin | 36 ++++++++++++++++++++++
src/lib/krb5/ccache/ccmarshal.c | 53 +++++++++++++++++++++++++++++++++
src/lib/krb5/ccache/t_marshal.c | 15 +++++++++-
src/lib/krb5/libkrb5.exports | 2 ++
src/lib/krb5_32.def | 4 +++
6 files changed, 111 insertions(+), 1 deletion(-)
diff --git a/doc/appdev/refs/api/index.rst b/doc/appdev/refs/api/index.rst
index 727d9b492..9e03fd386 100644
--- a/doc/appdev/refs/api/index.rst
+++ b/doc/appdev/refs/api/index.rst
@@ -232,6 +232,7 @@ Rarely used public interfaces
krb5_kt_remove_entry.rst
krb5_kt_start_seq_get.rst
krb5_make_authdata_kdc_issued.rst
+ krb5_marshal_credentials.rst
krb5_merge_authdata.rst
krb5_mk_1cred.rst
krb5_mk_error.rst
@@ -285,6 +286,7 @@ Rarely used public interfaces
krb5_tkt_creds_get_times.rst
krb5_tkt_creds_init.rst
krb5_tkt_creds_step.rst
+ krb5_unmarshal_credentials.rst
krb5_verify_init_creds.rst
krb5_verify_init_creds_opt_init.rst
krb5_verify_init_creds_opt_set_ap_req_nofail.rst
diff --git a/src/include/krb5/krb5.hin b/src/include/krb5/krb5.hin
index 63e67a2ba..c26dde535 100644
--- a/src/include/krb5/krb5.hin
+++ b/src/include/krb5/krb5.hin
@@ -3125,6 +3125,42 @@ krb5_get_credentials(krb5_context context, krb5_flags options,
krb5_ccache ccache, krb5_creds *in_creds,
krb5_creds **out_creds);
+/**
+ * Serialize a @c krb5_creds object.
+ *
+ * @param [in] context Library context
+ * @param [in] creds The credentials object to serialize
+ * @param [out] data_out The serialized credentials
+ *
+ * Serialize @a creds in the format used by the FILE ccache format (vesion 4)
+ * and KCM ccache protocol.
+ *
+ * Use krb5_free_data() to free @a data_out when it is no longer needed.
+ *
+ * @retval 0 Success; otherwise - Kerberos error codes
+ */
+krb5_error_code KRB5_CALLCONV
+krb5_marshal_credentials(krb5_context context, krb5_creds *in_creds,
+ krb5_data **data_out);
+
+/**
+ * Deserialize a @c krb5_creds object.
+ *
+ * @param [in] context Library context
+ * @param [in] data The serialized credentials
+ * @param [out] creds_out The resulting creds object
+ *
+ * Deserialize @a data to credentials in the format used by the FILE ccache
+ * format (vesion 4) and KCM ccache protocol.
+ *
+ * Use krb5_free_creds() to free @a creds_out when it is no longer needed.
+ *
+ * @retval 0 Success; otherwise - Kerberos error codes
+ */
+krb5_error_code KRB5_CALLCONV
+krb5_unmarshal_credentials(krb5_context context, const krb5_data *data,
+ krb5_creds **creds_out);
+
/** @deprecated Replaced by krb5_get_validated_creds. */
krb5_error_code KRB5_CALLCONV
krb5_get_credentials_validate(krb5_context context, krb5_flags options,
diff --git a/src/lib/krb5/ccache/ccmarshal.c b/src/lib/krb5/ccache/ccmarshal.c
index ae634ccab..ab284e721 100644
--- a/src/lib/krb5/ccache/ccmarshal.c
+++ b/src/lib/krb5/ccache/ccmarshal.c
@@ -515,3 +515,56 @@ k5_marshal_mcred(struct k5buf *buf, krb5_creds *mcred)
if (mcred->second_ticket.length > 0)
put_data(buf, version, &mcred->second_ticket);
}
+
+krb5_error_code KRB5_CALLCONV
+krb5_marshal_credentials(krb5_context context, krb5_creds *in_creds,
+ krb5_data **data_out)
+{
+ krb5_error_code ret;
+ krb5_data *data;
+ struct k5buf buf;
+
+ *data_out = NULL;
+
+ data = k5alloc(sizeof(krb5_data), &ret);
+ if (ret)
+ return ret;
+
+ k5_buf_init_dynamic(&buf);
+ k5_marshal_cred(&buf, 4, in_creds);
+
+ ret = k5_buf_status(&buf);
+ if (ret) {
+ free(data);
+ return ret;
+ }
+
+ /* Steal payload from buf. */
+ *data = make_data(buf.data, buf.len);
+ *data_out = data;
+ return 0;
+}
+
+krb5_error_code KRB5_CALLCONV
+krb5_unmarshal_credentials(krb5_context context, const krb5_data *data,
+ krb5_creds **creds_out)
+{
+ krb5_error_code ret;
+ krb5_creds *creds;
+
+ *creds_out = NULL;
+
+ creds = k5alloc(sizeof(krb5_creds), &ret);
+ if (ret)
+ return ret;
+
+ ret = k5_unmarshal_cred((unsigned char *)data->data, data->length, 4,
+ creds);
+ if (ret) {
+ free(creds);
+ return ret;
+ }
+
+ *creds_out = creds;
+ return 0;
+}
diff --git a/src/lib/krb5/ccache/t_marshal.c b/src/lib/krb5/ccache/t_marshal.c
index bd0284afa..96e0931a2 100644
--- a/src/lib/krb5/ccache/t_marshal.c
+++ b/src/lib/krb5/ccache/t_marshal.c
@@ -268,13 +268,14 @@ main(int argc, char **argv)
krb5_context context;
krb5_ccache cache;
krb5_principal princ;
- krb5_creds cred1, cred2;
+ krb5_creds cred1, cred2, *alloc_cred;
krb5_cc_cursor cursor;
const char *filename;
char *ccname, filebuf[256];
int version, fd;
const struct test *t;
struct k5buf buf;
+ krb5_data ser_data, *alloc_data;
if (argc != 2)
abort();
@@ -285,6 +286,18 @@ main(int argc, char **argv)
if (krb5_init_context(&context) != 0)
abort();
+ /* Test public functions for unmarshalling and marshalling. */
+ ser_data = make_data((char *)tests[3].cred1, tests[3].cred1len);
+ if (krb5_unmarshal_credentials(context, &ser_data, &alloc_cred) != 0)
+ abort();
+ verify_cred1(alloc_cred);
+ if (krb5_marshal_credentials(context, alloc_cred, &alloc_data) != 0)
+ abort();
+ assert(alloc_data->length == tests[3].cred1len);
+ assert(memcmp(tests[3].cred1, alloc_data->data, alloc_data->length) == 0);
+ krb5_free_data(context, alloc_data);
+ krb5_free_creds(context, alloc_cred);
+
for (version = FIRST_VERSION; version <= 4; version++) {
t = &tests[version - 1];
diff --git a/src/lib/krb5/libkrb5.exports b/src/lib/krb5/libkrb5.exports
index 2d9d56530..adbfa332b 100644
--- a/src/lib/krb5/libkrb5.exports
+++ b/src/lib/krb5/libkrb5.exports
@@ -489,6 +489,7 @@ krb5_lock_file
krb5_make_authdata_kdc_issued
krb5_make_full_ipaddr
krb5_make_fulladdr
+krb5_marshal_credentials
krb5_mcc_ops
krb5_merge_authdata
krb5_mk_1cred
@@ -592,6 +593,7 @@ krb5_timeofday
krb5_timestamp_to_sfstring
krb5_timestamp_to_string
krb5_unlock_file
+krb5_unmarshal_credentials
krb5_unpack_full_ipaddr
krb5_unparse_name
krb5_unparse_name_ext
diff --git a/src/lib/krb5_32.def b/src/lib/krb5_32.def
index 4953907aa..60b8dd311 100644
--- a/src/lib/krb5_32.def
+++ b/src/lib/krb5_32.def
@@ -503,3 +503,7 @@ EXPORTS
; new in 1.19
k5_cc_store_primary_cred @470 ; PRIVATE
k5_kt_have_match @471 ; PRIVATE GSSAPI
+
+; new in 1.20
+ krb5_marshal_credentials @472
+ krb5_unmarshal_credentials @473