krb5_k_make_checksum: 0 cksumtype means use mandatory cksum for given enctype

git-svn-id: svn://anonsvn.mit.edu/krb5/users/hartmans/fast-negotiate@23326 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 11 insertions, 2 deletions

diff --git a/src/lib/crypto/krb/make_checksum.c b/src/lib/crypto/krb/make_checksum.c
index 06a5247..bffc59b 100644
--- a/src/lib/crypto/krb/make_checksum.c
+++ b/src/lib/crypto/krb/make_checksum.c
@@ -29,10 +29,12 @@
 #include "etypes.h"
 #include "dk.h"
 
+/* A 0 checksum type means use the mandatory checksum*/
+
 krb5_error_code KRB5_CALLCONV
 krb5_k_make_checksum(krb5_context context, krb5_cksumtype cksumtype,
-		     krb5_key key, krb5_keyusage usage,
-		     const krb5_data *input, krb5_checksum *cksum)
+                     krb5_key key, krb5_keyusage usage,
+                     const krb5_data *input, krb5_checksum *cksum)
 {
     unsigned int i;
     const struct krb5_cksumtypes *ctp;
@@ -43,6 +45,12 @@ krb5_k_make_checksum(krb5_context context, krb5_cksumtype cksumtype,
     krb5_error_code ret;
     size_t cksumlen;
 
+    if (cksumtype == 0) {
+        ret = krb5int_c_mandatory_cksumtype(context, krb5_k_key_enctype(context, key), &cksumtype);
+        if (ret != 0)
+            return ret;
+    }
+
     for (i = 0; i < krb5int_cksumtypes_length; i++) {
 	if (krb5int_cksumtypes_list[i].ctype == cksumtype)
 	    break;
@@ -57,6 +65,7 @@ krb5_k_make_checksum(krb5_context context, krb5_cksumtype cksumtype,
 	cksumlen = ctp->hash->hashsize;
 
     cksum->length = cksumlen;
+    cksum->checksum_type = cksumtype;
     cksum->contents = malloc(cksum->length);
     if (cksum->contents == NULL)
 	return ENOMEM;