krb5 commit: Correct error handling bug in prior commit

[Greg Hudson]

https://github.com/krb5/krb5/commit/7fdaef7c3280c86b5df25ae061fb04cc56d8620c
commit 7fdaef7c3280c86b5df25ae061fb04cc56d8620c
Author: Greg Hudson <ghudson at mit.edu>
Date:   Thu Mar 23 13:42:55 2017 -0400

    Correct error handling bug in prior commit
    
    In crypto_encode_der_cert(), if the second i2d_X509() invocation
    fails, make sure to free the allocated pointer and not the
    possibly-modified alias.
    
    ticket: 8561

 src/plugins/preauth/pkinit/pkinit_crypto_openssl.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c
index a1ba911..be4fc47 100644
--- a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c
+++ b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c
@@ -6114,10 +6114,10 @@ crypto_encode_der_cert(krb5_context context, pkinit_req_crypto_context reqctx,
     if (len <= 0)
         return EINVAL;
     p = der = malloc(len);
-    if (p == NULL)
+    if (der == NULL)
         return ENOMEM;
     if (i2d_X509(reqctx->received_cert, &p) <= 0) {
-        free(p);
+        free(der);
         return EINVAL;
     }
     *der_out = der;