s4:kdc: fix calculation of the rodc kvno

Bit shifting is non-trivial in C:-)

This

	int32_t a = 0x12340000;
	uint32_t b = (a >> 16);

results in 0x00001234, but this

	int32_t a = 0xEDCB0000;
	uint32_t b = (a >> 16);

results in 0xFFFFEDCB, while we expected 0x0000EDCB.

metze

diff --git a/source4/kdc/db-glue.c b/source4/kdc/db-glue.c
index ed64685a4fc2cff11c8edcb68dd4901d9c594e52..7a3b1f4f69dc075d5d43a3fda48c68299b9ef76e 100644 (file)
--- a/source4/kdc/db-glue.c
+++ b/source4/kdc/db-glue.c
@@ -36,6 +36,13 @@
 #include "kdc/samba_kdc.h"
 #include "kdc/kdc-policy.h"
 
+#define SAMBA_KVNO_GET_KRBTGT(kvno) \
+       ((uint16_t)(((uint32_t)kvno) >> 16))
+
+#define SAMBA_KVNO_AND_KRBTGT(kvno, krbtgt) \
+       ((krb5_kvno)((((uint32_t)kvno) & 0xFFFF) | \
+        ((((uint32_t)krbtgt) << 16) & 0xFFFF0000)))
+
 enum samba_kdc_ent_type
 { SAMBA_KDC_ENT_TYPE_CLIENT, SAMBA_KDC_ENT_TYPE_SERVER,
   SAMBA_KDC_ENT_TYPE_KRBTGT, SAMBA_KDC_ENT_TYPE_TRUST, SAMBA_KDC_ENT_TYPE_ANY };
@@ -206,6 +213,7 @@ static krb5_error_code samba_kdc_message2entry_keys(krb5_context context,
        uint16_t i;
        uint16_t allocated_keys = 0;
        int rodc_krbtgt_number = 0;
+       int kvno = 0;
        uint32_t supported_enctypes
                = ldb_msg_find_attr_as_uint(msg,
                                            "msDS-SupportedEncryptionTypes",
@@ -245,14 +253,14 @@ static krb5_error_code samba_kdc_message2entry_keys(krb5_context context,
                }
        }
 
-
        entry_ex->entry.keys.val = NULL;
        entry_ex->entry.keys.len = 0;
 
-       entry_ex->entry.kvno = ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0);
+       kvno = ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0);
        if (is_rodc) {
-               entry_ex->entry.kvno |= (rodc_krbtgt_number << 16);
+               kvno = SAMBA_KVNO_AND_KRBTGT(kvno, rodc_krbtgt_number);
        }
+       entry_ex->entry.kvno = kvno;
 
        /* Get keys from the db */
 
@@ -1334,7 +1342,7 @@ krb5_error_code samba_kdc_fetch(krb5_context context,
        TALLOC_CTX *mem_ctx;
        unsigned int krbtgt_number;
        if (flags & HDB_F_KVNO_SPECIFIED) {
-               krbtgt_number = kvno >> 16;
+               krbtgt_number = SAMBA_KVNO_GET_KRBTGT(kvno);
                if (kdc_db_ctx->rodc) {
                        if (krbtgt_number != kdc_db_ctx->my_krbtgt_number) {
                                return HDB_ERR_NOT_FOUND_HERE;