krb5_wrap: let smb_krb5_kinit_s4u2_ccache() work if store_creds.client and server...
[samba.git] / lib / krb5_wrap / krb5_samba.c
index dde85f9e2b9a5e7aacbadf49b59ee89cc79e50cd..bb0b5dfa6209c40751aa46a94e9a40646b22d167 100644 (file)
@@ -23,7 +23,6 @@
 #include "includes.h"
 #include "system/filesys.h"
 #include "krb5_samba.h"
-#include "lib/util/asn1.h"
 
 #ifdef HAVE_COM_ERR_H
 #include <com_err.h>
@@ -207,6 +206,8 @@ krb5_error_code smb_krb5_mk_error(krb5_context context,
                                  krb5_error_code error_code,
                                  const char *e_text,
                                  krb5_data *e_data,
+                                 const krb5_principal client,
+                                 const krb5_principal server,
                                  krb5_data *enc_err)
 {
        krb5_error_code code = EINVAL;
@@ -215,27 +216,59 @@ krb5_error_code smb_krb5_mk_error(krb5_context context,
                             error_code,
                             e_text,
                             e_data,
-                            NULL, /* client */
-                            NULL, /* server */
+                            client,
+                            server,
                             NULL, /* client_time */
                             NULL, /* client_usec */
                             enc_err);
 #else
-       krb5_error dec_err = {
-               .error = error_code,
-       };
+       krb5_principal unspec_server = NULL;
+       krb5_error errpkt;
 
+       errpkt.ctime = 0;
+       errpkt.cusec = 0;
+
+       code = krb5_us_timeofday(context,
+                                &errpkt.stime,
+                                &errpkt.susec);
+       if (code != 0) {
+               return code;
+       }
+
+       errpkt.error = error_code;
+
+       errpkt.text.length = 0;
        if (e_text != NULL) {
-               dec_err.text.length = strlen(e_text);
-               dec_err.text.data = discard_const_p(char, e_text);
+               errpkt.text.length = strlen(e_text);
+               errpkt.text.data = discard_const_p(char, e_text);
        }
+
+       errpkt.e_data.magic = KV5M_DATA;
+       errpkt.e_data.length = 0;
+       errpkt.e_data.data = NULL;
        if (e_data != NULL) {
-               dec_err.e_data = *e_data;
+               errpkt.e_data = *e_data;
+       }
+
+       errpkt.client = client;
+
+       if (server != NULL) {
+               errpkt.server = server;
+       } else {
+               code = smb_krb5_make_principal(context,
+                                              &unspec_server,
+                                              "<unspecified realm>",
+                                              NULL);
+               if (code != 0) {
+                       return code;
+               }
+               errpkt.server = unspec_server;
        }
 
        code = krb5_mk_error(context,
-                            &dec_err,
+                            &errpkt,
                             enc_err);
+       krb5_free_principal(context, unspec_server);
 #endif
        return code;
 }
@@ -386,61 +419,23 @@ krb5_error_code smb_krb5_get_allowed_etypes(krb5_context context,
 #error UNKNOWN_GET_ENCTYPES_FUNCTIONS
 #endif
 
-bool unwrap_edata_ntstatus(TALLOC_CTX *mem_ctx,
-                          DATA_BLOB *edata,
-                          DATA_BLOB *edata_out)
-{
-       DATA_BLOB edata_contents;
-       ASN1_DATA *data;
-       int edata_type;
-
-       if (!edata->length) {
-               return false;
-       }
-
-       data = asn1_init(mem_ctx);
-       if (data == NULL) {
-               return false;
-       }
-
-       if (!asn1_load(data, *edata)) goto err;
-       if (!asn1_start_tag(data, ASN1_SEQUENCE(0))) goto err;
-       if (!asn1_start_tag(data, ASN1_CONTEXT(1))) goto err;
-       if (!asn1_read_Integer(data, &edata_type)) goto err;
-
-       if (edata_type != KRB5_PADATA_PW_SALT) {
-               DEBUG(0,("edata is not of required type %d but of type %d\n",
-                       KRB5_PADATA_PW_SALT, edata_type));
-               goto err;
-       }
-
-       if (!asn1_start_tag(data, ASN1_CONTEXT(2))) goto err;
-       if (!asn1_read_OctetString(data, talloc_tos(), &edata_contents)) goto err;
-       if (!asn1_end_tag(data)) goto err;
-       if (!asn1_end_tag(data)) goto err;
-       if (!asn1_end_tag(data)) goto err;
-       asn1_free(data);
-
-       *edata_out = data_blob_talloc(mem_ctx, edata_contents.data, edata_contents.length);
-
-       data_blob_free(&edata_contents);
-
-       return true;
-
-  err:
-
-       asn1_free(data);
-       return false;
-}
-
-
-/**************************************************************
- krb5_parse_name that takes a UNIX charset.
-**************************************************************/
 
+/**
+ * @brief Convert a string principal name to a Kerberos principal.
+ *
+ * @param[in]  context  The library context
+ *
+ * @param[in]  name     The principal as a unix charset string.
+ *
+ * @param[out] principal The newly allocated principal.
+ *
+ * Use krb5_free_principal() to free a principal when it is no longer needed.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
 krb5_error_code smb_krb5_parse_name(krb5_context context,
-                               const char *name, /* in unix charset */
-                               krb5_principal *principal)
+                                   const char *name,
+                                   krb5_principal *principal)
 {
        krb5_error_code ret;
        char *utf8_name;
@@ -457,11 +452,26 @@ krb5_error_code smb_krb5_parse_name(krb5_context context,
        return ret;
 }
 
-/**************************************************************
- krb5_parse_name that returns a UNIX charset name. Must
- be freed with talloc_free() call.
-**************************************************************/
-
+/**
+ * @brief Convert a Kerberos principal structure to a string representation.
+ *
+ * The resulting string representation will be a unix charset name and is
+ * talloc'ed.
+ *
+ * @param[in]  mem_ctx  The talloc context to allocate memory on.
+ *
+ * @param[in]  context  The library context.
+ *
+ * @param[in]  principal The principal.
+ *
+ * @param[out] unix_name A string representation of the princpial name as with
+ *                       unix charset.
+ *
+ * Use talloc_free() to free the string representation if it is no longer
+ * needed.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
 krb5_error_code smb_krb5_unparse_name(TALLOC_CTX *mem_ctx,
                                      krb5_context context,
                                      krb5_const_principal principal,
@@ -485,25 +495,6 @@ krb5_error_code smb_krb5_unparse_name(TALLOC_CTX *mem_ctx,
        return 0;
 }
 
-krb5_error_code smb_krb5_parse_name_norealm(krb5_context context, 
-                                           const char *name, 
-                                           krb5_principal *principal)
-{
-       /* we are cheating here because parse_name will in fact set the realm.
-        * We don't care as the only caller of smb_krb5_parse_name_norealm
-        * ignores the realm anyway when calling
-        * smb_krb5_principal_compare_any_realm later - Guenther */
-
-       return smb_krb5_parse_name(context, name, principal);
-}
-
-bool smb_krb5_principal_compare_any_realm(krb5_context context, 
-                                         krb5_const_principal princ1, 
-                                         krb5_const_principal princ2)
-{
-       return krb5_principal_compare_any_realm(context, princ1, princ2);
-}
-
 /**
  * @brief Free the contents of a krb5_data structure and zero the data field.
  *
@@ -896,87 +887,29 @@ krb5_error_code smb_krb5_gen_netbios_krb5_address(smb_krb5_addresses **kerb_addr
        return ret;
 }
 
- void smb_krb5_free_error(krb5_context context, krb5_error *krberror)
-{
-#ifdef HAVE_KRB5_FREE_ERROR_CONTENTS /* Heimdal */
-       krb5_free_error_contents(context, krberror);
-#else /* MIT */
-       krb5_free_error(context, krberror);
-#endif
-}
-
- krb5_error_code handle_krberror_packet(krb5_context context,
-                                       krb5_data *packet)
-{
-       krb5_error_code ret;
-       bool got_error_code = false;
-
-       DEBUG(10,("handle_krberror_packet: got error packet\n"));
-
-#ifdef HAVE_E_DATA_POINTER_IN_KRB5_ERROR /* Heimdal */
-       {
-               krb5_error krberror;
-
-               if ((ret = krb5_rd_error(context, packet, &krberror))) {
-                       DEBUG(10,("handle_krberror_packet: krb5_rd_error failed with: %s\n",
-                               error_message(ret)));
-                       return ret;
-               }
-
-               if (krberror.e_data == NULL || krberror.e_data->data == NULL) {
-                       ret = (krb5_error_code) krberror.error_code;
-                       got_error_code = true;
-               }
-
-               smb_krb5_free_error(context, &krberror);
-       }
-#else /* MIT */
-       {
-               krb5_error *krberror;
-
-               if ((ret = krb5_rd_error(context, packet, &krberror))) {
-                       DEBUG(10,("handle_krberror_packet: krb5_rd_error failed with: %s\n",
-                               error_message(ret)));
-                       return ret;
-               }
-
-               if (krberror->e_data.data == NULL) {
-#if defined(ERROR_TABLE_BASE_krb5)
-                       ret = ERROR_TABLE_BASE_krb5 + (krb5_error_code) krberror->error;
-#else
-                       ret = (krb5_error_code)krberror->error;
-#endif
-                       got_error_code = true;
-               }
-               smb_krb5_free_error(context, krberror);
-       }
-#endif
-       if (got_error_code) {
-               DEBUG(5,("handle_krberror_packet: got KERBERR from kpasswd: %s (%d)\n",
-                       error_message(ret), ret));
-       }
-       return ret;
-}
-
-krb5_error_code smb_krb5_get_init_creds_opt_alloc(krb5_context context,
-                                           krb5_get_init_creds_opt **opt)
-{
-       /* Heimdal or modern MIT version */
-       return krb5_get_init_creds_opt_alloc(context, opt);
-}
-
-void smb_krb5_get_init_creds_opt_free(krb5_context context,
-                               krb5_get_init_creds_opt *opt)
-{
-       /* Modern MIT or Heimdal version */
-       krb5_get_init_creds_opt_free(context, opt);
-}
-
-krb5_enctype smb_get_enctype_from_kt_entry(krb5_keytab_entry *kt_entry)
+/**
+ * @brief Get the enctype from a key table entry
+ *
+ * @param[in]  kt_entry Key table entry to get the enctype from.
+ *
+ * @return The enctype from the entry.
+ */
+krb5_enctype smb_krb5_kt_get_enctype_from_entry(krb5_keytab_entry *kt_entry)
 {
        return KRB5_KEY_TYPE(KRB5_KT_KEY(kt_entry));
 }
 
+/**
+ * @brief Free the contents of a key table entry.
+ *
+ * @param[in]  context The library context.
+ *
+ * @param[in]  kt_entry The key table entry to free the contents of.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ *
+ * The pointer itself is not freed.
+ */
 krb5_error_code smb_krb5_kt_free_entry(krb5_context context,
                                        krb5_keytab_entry *kt_entry)
 {
@@ -995,7 +928,20 @@ krb5_error_code smb_krb5_kt_free_entry(krb5_context context,
 }
 
 
-/* caller needs to free etype_s */
+/**
+ * @brief Convert an encryption type to a string.
+ *
+ * @param[in]  context The library context.
+ *
+ * @param[in]  enctype The encryption type.
+ *
+ * @param[in]  etype_s A pointer to store the allocated encryption type as a
+ *                     string.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ *
+ * The caller needs to free the allocated string etype_s.
+ */
 krb5_error_code smb_krb5_enctype_to_string(krb5_context context,
                                           krb5_enctype enctype,
                                           char **etype_s)
@@ -1018,25 +964,33 @@ krb5_error_code smb_krb5_enctype_to_string(krb5_context context,
 #endif
 }
 
-/**********************************************************************
- * Open a krb5 keytab with flags, handles readonly or readwrite access and
- * allows one to process non-default keytab names.
- * @param context krb5_context
- * @param keytab_name_req string
- * @param write_access bool if writable keytab is required
- * @param krb5_keytab pointer to krb5_keytab (close with krb5_kt_close())
- * @return krb5_error_code
-**********************************************************************/
-
 /* This MAX_NAME_LEN is a constant defined in krb5.h */
 #ifndef MAX_KEYTAB_NAME_LEN
 #define MAX_KEYTAB_NAME_LEN 1100
 #endif
 
-krb5_error_code smb_krb5_open_keytab_relative(krb5_context context,
-                                             const char *keytab_name_req,
-                                             bool write_access,
-                                             krb5_keytab *keytab)
+/**
+ * @brief Open a key table readonly or with readwrite access.
+ *
+ * Allows to use a different keytab than the default one using a relative
+ * path to the keytab.
+ *
+ * @param[in]  context  The library context
+ *
+ * @param[in]  keytab_name_req The path to the key table.
+ *
+ * @param[in]  write_access Open with readwrite access.
+ *
+ * @param[in]  keytab A pointer o the opended key table.
+ *
+ * The keytab pointer should be freed using krb5_kt_close().
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
+krb5_error_code smb_krb5_kt_open_relative(krb5_context context,
+                                         const char *keytab_name_req,
+                                         bool write_access,
+                                         krb5_keytab *keytab)
 {
        krb5_error_code ret = 0;
        TALLOC_CTX *mem_ctx;
@@ -1069,8 +1023,8 @@ krb5_error_code smb_krb5_open_keytab_relative(krb5_context context,
                        goto out;
                }
 
-               if ((strncmp(keytab_name_req, "WRFILE:/", 8) == 0) ||
-                   (strncmp(keytab_name_req, "FILE:/", 6) == 0)) {
+               if ((strncmp(keytab_name_req, "WRFILE:", 7) == 0) ||
+                   (strncmp(keytab_name_req, "FILE:", 5) == 0)) {
                        tmp = keytab_name_req;
                        goto resolve;
                }
@@ -1144,33 +1098,83 @@ krb5_error_code smb_krb5_open_keytab_relative(krb5_context context,
                goto out;
        }
 
- resolve:
+resolve:
        DEBUG(10,("smb_krb5_open_keytab: resolving: %s\n", tmp));
        ret = krb5_kt_resolve(context, tmp, keytab);
 
- out:
+out:
        TALLOC_FREE(mem_ctx);
        return ret;
 }
 
-krb5_error_code smb_krb5_open_keytab(krb5_context context,
-                                    const char *keytab_name_req,
-                                    bool write_access,
-                                    krb5_keytab *keytab)
+/**
+ * @brief Open a key table readonly or with readwrite access.
+ *
+ * Allows to use a different keytab than the default one. The path needs to be
+ * an absolute path or an error will be returned.
+ *
+ * @param[in]  context  The library context
+ *
+ * @param[in]  keytab_name_req The path to the key table.
+ *
+ * @param[in]  write_access Open with readwrite access.
+ *
+ * @param[in]  keytab A pointer o the opended key table.
+ *
+ * The keytab pointer should be freed using krb5_kt_close().
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
+krb5_error_code smb_krb5_kt_open(krb5_context context,
+                                const char *keytab_name_req,
+                                bool write_access,
+                                krb5_keytab *keytab)
 {
-       if (keytab_name_req != NULL) {
-               if (keytab_name_req[0] != '/') {
-                       return KRB5_KT_BADNAME;
-               }
+       int cmp;
+
+       if (keytab_name_req == NULL) {
+               return KRB5_KT_BADNAME;
        }
 
-       return smb_krb5_open_keytab_relative(context,
-                                            keytab_name_req,
-                                            write_access,
-                                            keytab);
+       if (keytab_name_req[0] == '/') {
+               goto open_keytab;
+       }
+
+       cmp = strncmp(keytab_name_req, "FILE:/", 6);
+       if (cmp == 0) {
+               goto open_keytab;
+       }
+
+       cmp = strncmp(keytab_name_req, "WRFILE:/", 8);
+       if (cmp == 0) {
+               goto open_keytab;
+       }
+
+       return KRB5_KT_BADNAME;
+
+open_keytab:
+       return smb_krb5_kt_open_relative(context,
+                                        keytab_name_req,
+                                        write_access,
+                                        keytab);
 }
 
-krb5_error_code smb_krb5_keytab_name(TALLOC_CTX *mem_ctx,
+/**
+ * @brief Get a key table name.
+ *
+ * @param[in]  mem_ctx The talloc context to use for allocation.
+ *
+ * @param[in]  context The library context.
+ *
+ * @param[in]  keytab The key table to get the name from.
+ *
+ * @param[in]  keytab_name A talloc'ed string of the key table name.
+ *
+ * The talloc'ed name string needs to be freed with talloc_free().
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
+krb5_error_code smb_krb5_kt_get_name(TALLOC_CTX *mem_ctx,
                                     krb5_context context,
                                     krb5_keytab keytab,
                                     const char **keytab_name)
@@ -1225,17 +1229,13 @@ krb5_error_code smb_krb5_kt_seek_and_delete_old_entries(krb5_context context,
 {
        krb5_error_code ret;
        krb5_kt_cursor cursor;
-       krb5_kt_cursor zero_csr;
        krb5_keytab_entry kt_entry;
-       krb5_keytab_entry zero_kt_entry;
        char *ktprinc = NULL;
        krb5_kvno old_kvno = kvno - 1;
        TALLOC_CTX *tmp_ctx;
 
        ZERO_STRUCT(cursor);
-       ZERO_STRUCT(zero_csr);
        ZERO_STRUCT(kt_entry);
-       ZERO_STRUCT(zero_kt_entry);
 
        ret = krb5_kt_start_seq_get(context, keytab, &cursor);
        if (ret == KRB5_KT_END || ret == ENOENT ) {
@@ -1252,7 +1252,7 @@ krb5_error_code smb_krb5_kt_seek_and_delete_old_entries(krb5_context context,
        while (!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
                bool name_ok = false;
                krb5_enctype kt_entry_enctype =
-                       smb_get_enctype_from_kt_entry(&kt_entry);
+                       smb_krb5_kt_get_enctype_from_entry(&kt_entry);
 
                if (!flush && (princ_s != NULL)) {
                        ret = smb_krb5_unparse_name(tmp_ctx, context,
@@ -1370,10 +1370,10 @@ krb5_error_code smb_krb5_kt_seek_and_delete_old_entries(krb5_context context,
 
 out:
        talloc_free(tmp_ctx);
-       if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
+       if (!all_zero((uint8_t *)&kt_entry, sizeof(kt_entry))) {
                smb_krb5_kt_free_entry(context, &kt_entry);
        }
-       if (memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) {
+       if (!all_zero((uint8_t *)&cursor, sizeof(cursor))) {
                krb5_kt_end_seq_get(context, keytab, &cursor);
        }
        return ret;
@@ -1409,7 +1409,7 @@ out:
  *
  * @return A corresponding KRB5 error code.
  *
- * @see smb_krb5_open_keytab()
+ * @see smb_krb5_kt_open()
  */
 krb5_error_code smb_krb5_kt_add_entry(krb5_context context,
                                      krb5_keytab keytab,
@@ -1656,6 +1656,27 @@ krb5_error_code smb_krb5_get_credentials(krb5_context context,
        return ret;
 }
 
+/**
+ * @brief Initialize a krb5_keyblock with the given data.
+ *
+ * Initialized a new keyblock, allocates the contents fo the key and
+ * copies the data into the keyblock.
+ *
+ * @param[in]  context  The library context
+ *
+ * @param[in]  enctype  The encryption type.
+ *
+ * @param[in]  data     The date to initialize the keyblock with.
+ *
+ * @param[in]  length   The length of the keyblock.
+ *
+ * @param[in]  key      Newly allocated keyblock structure.
+ *
+ * The key date must be freed using krb5_free_keyblock_contents() when it is
+ * no longer needed.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
 krb5_error_code smb_krb5_keyblock_init_contents(krb5_context context,
                                                krb5_enctype enctype,
                                                const void *data,
@@ -1677,26 +1698,39 @@ krb5_error_code smb_krb5_keyblock_init_contents(krb5_context context,
 #endif
 }
 
-/*
-  simulate a kinit, putting the tgt in the given credentials cache.
-  Orignally by remus@snapserver.com
-
-  This version is built to use a keyblock, rather than needing the
-  original password.
-
-  The impersonate_principal is the principal if NULL, or the principal
-  to impersonate
-
-  The target_service defaults to the krbtgt if NULL, but could be
-   kpasswd/realm or the local service (if we are doing s4u2self)
-*/
-krb5_error_code kerberos_kinit_keyblock_cc(krb5_context ctx, krb5_ccache cc,
-                                          krb5_principal principal,
-                                          krb5_keyblock *keyblock,
-                                          const char *target_service,
-                                          krb5_get_init_creds_opt *krb_options,
-                                          time_t *expire_time,
-                                          time_t *kdc_time)
+/**
+ * @brief Simulate a kinit by putting the tgt in the given credential cache.
+ *
+ * This function uses a keyblock rather than needingthe original password.
+ *
+ * @param[in]  ctx      The library context
+ *
+ * @param[in]  cc       The credential cache to put the tgt in.
+ *
+ * @param[in]  principal The client princial
+ *
+ * @param[in]  keyblock  The keyblock to use.
+ *
+ * @param[in]  target_service The service name of the initial credentials (or NULL).
+ *
+ * @param[in]  krb_options Initial credential options.
+ *
+ * @param[in]  expire_time    A pointer to store the experation time of the
+ *                            credentials (or NULL).
+ *
+ * @param[in]  kdc_time       A pointer to store the time when the ticket becomes
+ *                            valid (or NULL).
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
+krb5_error_code smb_krb5_kinit_keyblock_ccache(krb5_context ctx,
+                                              krb5_ccache cc,
+                                              krb5_principal principal,
+                                              krb5_keyblock *keyblock,
+                                              const char *target_service,
+                                              krb5_get_init_creds_opt *krb_options,
+                                              time_t *expire_time,
+                                              time_t *kdc_time)
 {
        krb5_error_code code = 0;
        krb5_creds my_creds;
@@ -1779,13 +1813,37 @@ done:
        return code;
 }
 
-krb5_error_code kerberos_kinit_password_cc(krb5_context ctx, krb5_ccache cc,
-                                          krb5_principal principal,
-                                          const char *password,
-                                          const char *target_service,
-                                          krb5_get_init_creds_opt *krb_options,
-                                          time_t *expire_time,
-                                          time_t *kdc_time)
+/**
+ * @brief Simulate a kinit by putting the tgt in the given credential cache.
+ *
+ * @param[in]  ctx      The library context
+ *
+ * @param[in]  cc       The credential cache to put the tgt in.
+ *
+ * @param[in]  principal The client princial
+ *
+ * @param[in]  password  The password (or NULL).
+ *
+ * @param[in]  target_service The service name of the initial credentials (or NULL).
+ *
+ * @param[in]  krb_options Initial credential options.
+ *
+ * @param[in]  expire_time    A pointer to store the experation time of the
+ *                            credentials (or NULL).
+ *
+ * @param[in]  kdc_time       A pointer to store the time when the ticket becomes
+ *                            valid (or NULL).
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
+krb5_error_code smb_krb5_kinit_password_ccache(krb5_context ctx,
+                                              krb5_ccache cc,
+                                              krb5_principal principal,
+                                              const char *password,
+                                              const char *target_service,
+                                              krb5_get_init_creds_opt *krb_options,
+                                              time_t *expire_time,
+                                              time_t *kdc_time)
 {
        krb5_error_code code = 0;
        krb5_creds my_creds;
@@ -1830,29 +1888,46 @@ done:
 }
 
 #ifdef SAMBA4_USES_HEIMDAL
-/*
-  simulate a kinit, putting the tgt in the given credentials cache.
-  Orignally by remus@snapserver.com
-
-  The impersonate_principal is the principal
-
-  The self_service, should be the local service (for S4U2Self if
-  impersonate_principal is given).
-
-  The target_service defaults to the krbtgt if NULL, but could be
-  kpasswd/realm or a remote service (for S4U2Proxy)
-
-*/
-krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
-                                       krb5_ccache store_cc,
-                                       krb5_principal init_principal,
-                                       const char *init_password,
-                                       krb5_principal impersonate_principal,
-                                       const char *self_service,
-                                       const char *target_service,
-                                       krb5_get_init_creds_opt *krb_options,
-                                       time_t *expire_time,
-                                       time_t *kdc_time)
+/**
+ * @brief Simulate a kinit by putting the tgt in the given credential cache.
+ *
+ * @param[in]  ctx      The library context
+ *
+ * @param[in]  cc       The credential cache to store the tgt in.
+ *
+ * @param[in]  principal The initial client princial.
+ *
+ * @param[in]  password  The password (or NULL).
+ *
+ * @param[in]  impersonate_principal The impersonatiion principal (or NULL).
+ *
+ * @param[in]  self_service The local service for S4U2Self if
+ *                          impersonate_principal is specified).
+ *
+ * @param[in]  target_service The service name of the initial credentials
+ *                            (kpasswd/REALM or a remote service). It defaults
+ *                            to the krbtgt if NULL.
+ *
+ * @param[in]  krb_options Initial credential options.
+ *
+ * @param[in]  expire_time    A pointer to store the experation time of the
+ *                            credentials (or NULL).
+ *
+ * @param[in]  kdc_time       A pointer to store the time when the ticket becomes
+ *                            valid (or NULL).
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
+krb5_error_code smb_krb5_kinit_s4u2_ccache(krb5_context ctx,
+                                          krb5_ccache store_cc,
+                                          krb5_principal init_principal,
+                                          const char *init_password,
+                                          krb5_principal impersonate_principal,
+                                          const char *self_service,
+                                          const char *target_service,
+                                          krb5_get_init_creds_opt *krb_options,
+                                          time_t *expire_time,
+                                          time_t *kdc_time)
 {
        krb5_error_code code = 0;
        krb5_get_creds_opt options;
@@ -1867,6 +1942,7 @@ krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
        krb5_principal target_princ;
        krb5_ccache tmp_cc;
        const char *self_realm;
+       const char *client_realm = NULL;
        krb5_principal blacklist_principal = NULL;
        krb5_principal whitelist_principal = NULL;
 
@@ -2140,7 +2216,7 @@ krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
                if (code != 0) {
                        ip = NULL;
                }
-               DEBUG(1, ("kerberos_kinit_password_cc: "
+               DEBUG(1, ("smb_krb5_kinit_password_cache: "
                          "KDC returned self principal[%s] while impersonating [%s]\n",
                          sp?sp:"<no memory>",
                          ip?ip:"<no memory>"));
@@ -2170,7 +2246,7 @@ krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
                if (code != 0) {
                        ep = NULL;
                }
-               DEBUG(1, ("kerberos_kinit_password_cc: "
+               DEBUG(1, ("smb_krb5_kinit_password_cache: "
                          "KDC returned wrong principal[%s] we expected [%s]\n",
                          sp?sp:"<no memory>",
                          ep?ep:"<no memory>"));
@@ -2198,6 +2274,29 @@ krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
                return code;
        }
 
+       client_realm = krb5_principal_get_realm(ctx, store_creds.client);
+       if (client_realm != NULL) {
+               /*
+                * Because the CANON flag doesn't have any impact
+                * on the impersonate_principal => store_creds.client
+                * realm mapping. We need to store the credentials twice,
+                * once with the returned realm and once with the
+                * realm of impersonate_principal.
+                */
+               code = krb5_principal_set_realm(ctx, store_creds.server,
+                                               client_realm);
+               if (code != 0) {
+                       krb5_free_cred_contents(ctx, &store_creds);
+                       return code;
+               }
+
+               code = krb5_cc_store_cred(ctx, store_cc, &store_creds);
+               if (code != 0) {
+                       krb5_free_cred_contents(ctx, &store_creds);
+                       return code;
+               }
+       }
+
        if (expire_time) {
                *expire_time = (time_t) store_creds.times.endtime;
        }
@@ -2213,6 +2312,22 @@ krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
 #endif
 
 #if !defined(HAVE_KRB5_MAKE_PRINCIPAL) && defined(HAVE_KRB5_BUILD_PRINCIPAL_ALLOC_VA)
+/**
+ * @brief Create a principal name using a variable argument list.
+ *
+ * @param[in]  context  The library context.
+ *
+ * @param[inout]  principal A pointer to the principal structure.
+ *
+ * @param[in]  _realm    The realm to use. If NULL then the function will
+ *                       get the default realm name.
+ *
+ * @param[in]  ...       A list of 'char *' components, ending with NULL.
+ *
+ * Use krb5_free_principal() to free the principal when it is no longer needed.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
 krb5_error_code smb_krb5_make_principal(krb5_context context,
                                        krb5_principal *principal,
                                        const char *_realm, ...)
@@ -2308,6 +2423,29 @@ void smb_krb5_free_checksum_contents(krb5_context ctx, krb5_checksum *cksum)
 }
 #endif
 
+/**
+ * @brief Compute a checksum operating on a keyblock.
+ *
+ * This function computes a checksum over a PAC using the keyblock for a keyed
+ * checksum.
+ *
+ * @param[in]  mem_ctx A talloc context to alocate the signature on.
+ *
+ * @param[in]  pac_data The PAC as input.
+ *
+ * @param[in]  context  The library context.
+ *
+ * @param[in]  keyblock Encryption key for a keyed checksum.
+ *
+ * @param[out] sig_type The checksum type
+ *
+ * @param[out] sig_blob The talloc'ed checksum
+ *
+ * The caller must free the sig_blob with talloc_free() when it is not needed
+ * anymore.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
 krb5_error_code smb_krb5_make_pac_checksum(TALLOC_CTX *mem_ctx,
                                           DATA_BLOB *pac_data,
                                           krb5_context context,
@@ -2384,19 +2522,17 @@ krb5_error_code smb_krb5_make_pac_checksum(TALLOC_CTX *mem_ctx,
 }
 
 
-/*
- * smb_krb5_principal_get_realm
- *
+/**
  * @brief Get realm of a principal
  *
- * @param[in] context          The krb5_context
- * @param[in] principal                The principal
- * @return pointer to the realm
+ * @param[in] context   The library context
  *
- * Caller must free if the return value is not NULL.
+ * @param[in] principal The principal to get the realm from.
  *
+ * @return An allocated string with the realm or NULL if an error occured.
+ *
+ * The caller must free the realm string with free() if not needed anymore.
  */
-
 char *smb_krb5_principal_get_realm(krb5_context context,
                                   krb5_const_principal principal)
 {
@@ -2412,18 +2548,17 @@ char *smb_krb5_principal_get_realm(krb5_context context,
 #endif
 }
 
-/*
- * smb_krb5_principal_set_realm
- *
+/**
  * @brief Get realm of a principal
  *
- * @param[in] context          The krb5_context
- * @param[in] principal                The principal
- * @param[in] realm            The realm
- * @return                     0 on success, a krb5_error_code on error.
+ * @param[in] context   The library context
+ *
+ * @param[in] principal The principal to set the realm
  *
+ * @param[in] realm     The realm as a string to set.
+ *
+ * @retur 0 on success, a Kerberos error code otherwise.
  */
-
 krb5_error_code smb_krb5_principal_set_realm(krb5_context context,
                                             krb5_principal principal,
                                             const char *realm)
@@ -2560,7 +2695,24 @@ static char *smb_krb5_get_realm_from_hostname(TALLOC_CTX *mem_ctx,
        return realm;
 }
 
-char *kerberos_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
+/**
+ * @brief Get the principal as a string from the service hostname.
+ *
+ * @param[in]  mem_ctx  The talloc context
+ *
+ * @param[in]  service  The service name
+ *
+ * @param[in]  remote_name The remote name
+ *
+ * @param[in]  default_realm The default_realm if we cannot get it from the
+ *                           hostname or netbios name.
+ *
+ * @return A talloc'ed principal string or NULL if an error occured.
+ *
+ * The caller needs to free the principal with talloc_free() if it isn't needed
+ * anymore.
+ */
+char *smb_krb5_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
                                                   const char *service,
                                                   const char *remote_name,
                                                   const char *default_realm)
@@ -2583,8 +2735,7 @@ char *kerberos_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
                if (!realm) {
                        return NULL;
                }
-               DEBUG(3,("kerberos_get_principal_from_service_hostname: "
-                        "cannot get realm from, "
+               DEBUG(3,("Cannot get realm from, "
                         "desthost %s or default ccache. Using default "
                         "smb.conf realm %s\n",
                         remote_name,
@@ -2599,6 +2750,20 @@ char *kerberos_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
        return principal;
 }
 
+/**
+ * @brief Get an error string from a Kerberos error code.
+ *
+ * @param[in]  context  The library context.
+ *
+ * @param[in]  code     The Kerberos error code.
+ *
+ * @param[in]  mem_ctx  The talloc context to allocate the error string on.
+ *
+ * @return A talloc'ed error string or NULL if an error occured.
+ *
+ * The caller must free the returned error string with talloc_free() if not
+ * needed anymore
+ */
 char *smb_get_krb5_error_message(krb5_context context,
                                 krb5_error_code code,
                                 TALLOC_CTX *mem_ctx)
@@ -2620,15 +2785,12 @@ char *smb_get_krb5_error_message(krb5_context context,
 
 
 /**
-* @brief Return the kerberos library setting for "libdefaults:allow_weak_crypto"
-*
-* @param context       The krb5_context
-*
-* @return krb5_boolean
-*
-* Function returns true if weak crypto is allowd, false if not
-*/
-
+ * @brief Return the kerberos library setting for: libdefaults:allow_weak_crypto
+ *
+ * @param[in]  context  The library context
+ *
+ * @return True if weak crypto is allowed, false if not.
+ */
 krb5_boolean smb_krb5_get_allowed_weak_crypto(krb5_context context)
 #if defined(HAVE_KRB5_CONFIG_GET_BOOL_DEFAULT)
 {
@@ -2672,13 +2834,14 @@ krb5_boolean smb_krb5_get_allowed_weak_crypto(krb5_context context)
 #endif
 
 /**
-* @brief Return the type of a krb5_principal
-*
-* @param context       The krb5_context
-* @param principal     The const krb5_principal
-*
-* @return integer type of the principal
-*/
+ * @brief Return the type of a krb5_principal
+ *
+ * @param[in]  context  The library context.
+ *
+ * @param[in]  principal The principal to get the type from.
+ *
+ * @return The integer type of the principal.
+ */
 int smb_krb5_principal_get_type(krb5_context context,
                                krb5_const_principal principal)
 {
@@ -2692,13 +2855,14 @@ int smb_krb5_principal_get_type(krb5_context context,
 }
 
 /**
-* @brief Set the type of a krb5_principal
-*
-* @param context       The krb5_context
-* @param principal     The const krb5_principal
-* @param type          The principal type
-*
-*/
+ * @brief Set the type of a principal
+ *
+ * @param[in]  context  The library context
+ *
+ * @param[inout] principal The principal to set the type for.
+ *
+ * @param[in]  type     The principal type to set.
+ */
 void smb_krb5_principal_set_type(krb5_context context,
                                 krb5_principal principal,
                                 int type)
@@ -2712,34 +2876,61 @@ void smb_krb5_principal_set_type(krb5_context context,
 #endif
 }
 
-/**
-* @brief Generate a krb5 warning, forwarding to com_err
-*
-* @param context       The krb5_context
-* @param fmt           The message format
-* @param ...           The message arguments
-*
-* @return
-*/
 #if !defined(HAVE_KRB5_WARNX)
+/**
+ * @brief Log a Kerberos message
+ *
+ * It sends the message to com_err.
+ *
+ * @param[in]  context  The library context
+ *
+ * @param[in]  fmt      The message format
+ *
+ * @param[in]  ...      The message arguments
+ *
+ * @return 0 on success.
+ */
 krb5_error_code krb5_warnx(krb5_context context, const char *fmt, ...)
 {
        va_list args;
 
        va_start(args, fmt);
-       com_err_va("kdb_samba", errno, fmt, args);
+       com_err_va("samba-kdc", errno, fmt, args);
        va_end(args);
 
        return 0;
 }
 #endif
 
+/**
+ * @brief Copy a credential cache.
+ *
+ * @param[in]  context  The library context.
+ *
+ * @param[in]  incc     Credential cache to be copied.
+ *
+ * @param[inout] outcc  Copy of credential cache to be filled in.
+ *
+ * @return 0 on success, a Kerberos error code otherwise.
+ */
 krb5_error_code smb_krb5_cc_copy_creds(krb5_context context,
                                       krb5_ccache incc, krb5_ccache outcc)
 {
 #ifdef HAVE_KRB5_CC_COPY_CACHE /* Heimdal */
        return krb5_cc_copy_cache(context, incc, outcc);
 #elif defined(HAVE_KRB5_CC_COPY_CREDS)
+       krb5_error_code ret;
+       krb5_principal princ = NULL;
+
+       ret = krb5_cc_get_principal(context, incc, &princ);
+       if (ret != 0) {
+               return ret;
+       }
+       ret = krb5_cc_initialize(context, outcc, princ);
+       krb5_free_principal(context, princ);
+       if (ret != 0) {
+               return ret;
+       }
        return krb5_cc_copy_creds(context, incc, outcc);
 #else
 #error UNKNOWN_KRB5_CC_COPY_CACHE_OR_CREDS_FUNCTION
@@ -2994,7 +3185,7 @@ static krb5_error_code ads_krb5_mk_req(krb5_context context,
                        if (retval != 0) {
                                DBG_WARNING("krb5_auth_con_setuseruserkey "
                                            "failed (%s)\n",
-                                           error_message(retval)));
+                                           error_message(retval));
                                goto cleanup_creds;
                        }
 
@@ -3004,7 +3195,7 @@ static krb5_error_code ads_krb5_mk_req(krb5_context context,
                                                        KRB5_AUTH_CONTEXT_USE_SUBKEY);
                        if (retval != 0) {
                                DBG_WARNING("krb5_auth_con_setflags failed (%s)\n",
-                                           error_message(retval)));
+                                           error_message(retval));
                                goto cleanup_creds;
                        }
 
@@ -3036,7 +3227,7 @@ static krb5_error_code ads_krb5_mk_req(krb5_context context,
                                retval = ads_setup_auth_context(context, auth_context);
                                if (retval != 0) {
                                        DBG_WARNING("ads_setup_auth_context failed (%s)\n",
-                                                   error_message(retval)));
+                                                   error_message(retval));
                                        goto cleanup_creds;
                                }
                        } else {