From b8673bb9f05013eef1ae413e15ac995e9d215641 Mon Sep 17 00:00:00 2001 From: Jay Satiro Date: Sat, 30 May 2015 01:29:48 -0400 Subject: [PATCH] openssl: Fix verification of server-sent legacy intermediates - Try building a chain using issuers in the trusted store first to avoid problems with server-sent legacy intermediates. Prior to this change server-sent legacy intermediates with missing legacy issuers would cause verification to fail even if the client's CA bundle contained a valid replacement for the intermediate and an alternate chain could be constructed that would verify successfully. https://rt.openssl.org/Ticket/Display.html?id=3621&user=guest&pass=guest --- lib/vtls/openssl.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c index 6378e10ff..1df32558b 100644 --- a/lib/vtls/openssl.c +++ b/lib/vtls/openssl.c @@ -2013,6 +2013,20 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex) data->set.str[STRING_SSL_CRLFILE]: "none"); } + /* Try building a chain using issuers in the trusted store first to avoid + problems with server-sent legacy intermediates. + Newer versions of OpenSSL do alternate chain checking by default which + gives us the same fix without as much of a performance hit (slight), so we + prefer that if available. + https://rt.openssl.org/Ticket/Display.html?id=3621&user=guest&pass=guest + */ +#if defined(X509_V_FLAG_TRUSTED_FIRST) && !defined(X509_V_FLAG_NO_ALT_CHAINS) + if(data->set.ssl.verifypeer) { + X509_STORE_set_flags(SSL_CTX_get_cert_store(connssl->ctx), + X509_V_FLAG_TRUSTED_FIRST); + } +#endif + /* SSL always tries to verify the peer, this only says whether it should * fail to connect if the verification fails, or if it should continue * anyway. In the latter case the result of the verification is checked with