From 5af88441f4fb1951a0672c0c0e1979cd44acdb69 Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Fri, 23 Feb 2018 19:48:11 +0000
Subject: [PATCH] Allow multiple entries without a Subject even if
 unique_subject == yes

It is quite likely for there to be multiple certificates with empty
subjects, which are still distinct because of subjectAltName. Therefore
we allow multiple certificates with an empty Subject even if
unique_subject is set to yes.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5444)
---
 apps/ca.c       | 19 +++++++++++++++++++
 doc/man1/ca.pod |  4 ++++
 2 files changed, 23 insertions(+)

diff --git a/apps/ca.c b/apps/ca.c
index 1fdc2e417d..743e48185b 100644
--- a/apps/ca.c
+++ b/apps/ca.c
@@ -1721,6 +1721,20 @@ static int do_body(X509 **xret, EVP_PKEY *pkey, X509 *x509,
         goto end;
     }
 
+    if (row[DB_name][0] == '\0') {
+        /*
+         * An empty subject! We'll use the serial number instead. If
+         * unique_subject is in use then we don't want different entries with
+         * empty subjects matching each other.
+         */
+        OPENSSL_free(row[DB_name]);
+        row[DB_name] = OPENSSL_strdup(row[DB_serial]);
+        if (row[DB_name] == NULL) {
+            BIO_printf(bio_err, "Memory allocation failure\n");
+            goto end;
+        }
+    }
+
     if (db->attributes.unique_subject) {
         OPENSSL_STRING *crow = row;
 
@@ -2034,6 +2048,11 @@ static int do_revoke(X509 *x509, CA_DB *db, REVINFO_TYPE rev_type,
     else
         row[DB_serial] = BN_bn2hex(bn);
     BN_free(bn);
+    if (row[DB_name] != NULL && row[DB_name][0] == '\0') {
+        /* Entries with empty Subjects actually use the serial number instead */
+        OPENSSL_free(row[DB_name]);
+        row[DB_name] = OPENSSL_strdup(row[DB_serial]);
+    }
     if ((row[DB_name] == NULL) || (row[DB_serial] == NULL)) {
         BIO_printf(bio_err, "Memory allocation failure\n");
         goto end;
diff --git a/doc/man1/ca.pod b/doc/man1/ca.pod
index 9c5af4a891..c09f98e96f 100644
--- a/doc/man1/ca.pod
+++ b/doc/man1/ca.pod
@@ -469,6 +469,10 @@ versions of OpenSSL.  However, to make CA certificate roll-over easier,
 it's recommended to use the value B<no>, especially if combined with
 the B<-selfsign> command line option.
 
+Note that it is valid in some circumstances for certificates to be created
+without any subject. In the case where there are multiple certificates without
+subjects this does not count as a duplicate. 
+
 =item B<serial>
 
 A text file containing the next serial number to use in hex. Mandatory.
-- 
2.25.1