Add and use k5memdup, k5memdup0 helpers

Add k5-int.h static functions to duplicate byte ranges, optionally
with a trailing zero byte, and set an error code like k5alloc does.
Use them where they would shorten existing code.

2 files changed, 5 insertions, 10 deletions

diff --git a/src/kdc/fast_util.c b/src/kdc/fast_util.c
index 1dd5f3ebf3..40c5783035 100644
--- a/src/kdc/fast_util.c
+++ b/src/kdc/fast_util.c
@@ -256,15 +256,12 @@ kdc_find_fast(krb5_kdc_req **requestptr,
         } else {
             new_padata->pa_type = KRB5_PADATA_FX_COOKIE;
             new_padata->length = cookie_padata->length;
-            new_padata->contents = malloc(new_padata->length);
-            if (new_padata->contents == NULL) {
-                retval = ENOMEM;
+            new_padata->contents =
+                k5memdup(cookie_padata->contents, new_padata->length, &retval);
+            if (new_padata->contents == NULL)
                 free(new_padata);
-            } else {
-                memcpy(new_padata->contents, cookie_padata->contents,
-                       new_padata->length);
+            else
                 state->cookie = new_padata;
-            }
         }
     }
     if (retval == 0 && inner_body_out != NULL) {
diff --git a/src/kdc/kdc_preauth.c b/src/kdc/kdc_preauth.c
index 848d0bdccc..c2bcab9f3b 100644
--- a/src/kdc/kdc_preauth.c
+++ b/src/kdc/kdc_preauth.c
@@ -1586,12 +1586,10 @@ return_pw_salt(krb5_context context, krb5_pa_data *in_padata,
     padata->magic = KV5M_PA_DATA;
 
     if (salttype == KRB5_KDB_SALTTYPE_AFS3) {
-        padata->contents = k5alloc(salt->length + 1, &retval);
+        padata->contents = k5memdup0(salt->data, salt->length, &retval);
         if (padata->contents == NULL)
             goto cleanup;
-        memcpy(padata->contents, salt->data, salt->length);
         padata->pa_type = KRB5_PADATA_AFS3_SALT;
-        padata->contents[salt->length] = '\0';
         padata->length = salt->length + 1;
     } else {
         padata->pa_type = KRB5_PADATA_PW_SALT;