Issue proftpd#859, proftpd#861: Fix handling of CRL lookups by proper…

…ly using issuer for lookups, and guarding against null pointers.
Sashan · Dec 16, 2019 · 36b6bdf · 36b6bdf
1 parent 9a18af0
commit 36b6bdf
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/NEWS b/NEWS
@@ -28,6 +28,7 @@
   for symlinks (CVE-2017-7418).
 - Bug 4299 - TimeoutLogin not working for SFTP connections.
 - Issue 846 - Remote denial-of-service due to issue in network IO handling.
+- Issue 859 - Improper handling of TLS CRL lookups.
 
 1.3.6rc4 - Released 15-Jan-2017
 --------------------------------

diff --git a/contrib/mod_tls.c b/contrib/mod_tls.c
@@ -8972,10 +8972,10 @@ static int tls_verify_crl(int ok, X509_STORE_CTX *ctx) {
 
 #if OPENSSL_VERSION_NUMBER >= 0x10100000L && \
     !defined(HAVE_LIBRESSL)
-  crls = X509_STORE_CTX_get1_crls(store_ctx, subject);
+  crls = X509_STORE_CTX_get1_crls(store_ctx, issuer);
 #elif OPENSSL_VERSION_NUMBER >= 0x10000000L && \
       !defined(HAVE_LIBRESSL)
-  crls = X509_STORE_get1_crls(store_ctx, subject);
+  crls = X509_STORE_get1_crls(store_ctx, issuer);
 #else
   /* Your OpenSSL is before 1.0.0.  You really need to upgrade. */
   crls = NULL;
@@ -8994,6 +8994,9 @@ static int tls_verify_crl(int ok, X509_STORE_CTX *ctx) {
         ASN1_INTEGER *sn;
 
         revoked = sk_X509_REVOKED_value(X509_CRL_get_REVOKED(crl), j);
+        if (revoked == NULL) {
+          continue;
+        }
 #if OPENSSL_VERSION_NUMBER >= 0x10100000L && \
     !defined(HAVE_LIBRESSL)
         sn = X509_REVOKED_get0_serialNumber(revoked);