postgres.git / summary / log / commit / refs

commit    2c2c5f0e02b58d225385f5008fb797a90935cb06
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Fri May 22 00:41:55 2015 +0000
First released in: 9.0.21, 9.1.17, 9.2.12, 9.3.8

    Back-patch libpq support for TLS versions beyond v1.
    
    Since 7.3.2, libpq has been coded in such a way that the only SSL protocol
    it would allow was TLS v1.  That approach is looking increasingly obsolete.
    In commit 820f08cabdcbb899 we fixed it to allow TLS >= v1, but did not
    back-patch the change at the time, partly out of caution and partly because
    the question was confused by a contemporary server-side change to reject
    the now-obsolete SSL protocol v3.  9.4 has now been out long enough that
    it seems safe to assume the change is OK; hence, back-patch into 9.0-9.3.
    
    (I also chose to back-patch some relevant comments added by commit
    326e1d73c476a0b5, but did *not* change the server behavior; hence, pre-9.4
    servers will continue to allow SSL v3, even though no remotely modern
    client will request it.)
    
    Per gripe from Jan Bilek.


 src/backend/libpq/be-secure.c    |  7 +++++++
 src/interfaces/libpq/fe-secure.c | 11 ++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/backend/libpq/be-secure.c b/src/backend/libpq/be-secure.c
index 6ddcfd8476f..9b7bc619e34 100644
--- a/src/backend/libpq/be-secure.c
+++ b/src/backend/libpq/be-secure.c
@@ -735,6 +735,13 @@ initialize_SSL(void)
 #endif
 		SSL_library_init();
 		SSL_load_error_strings();
+
+		/*
+		 * We use SSLv23_method() because it can negotiate use of the highest
+		 * mutually supported protocol version, while alternatives like
+		 * TLSv1_2_method() permit only one specific version.  Note that we
+		 * don't actually allow SSL v2, only v3 and TLS protocols (see below).
+		 */
 		SSL_context = SSL_CTX_new(SSLv23_method());
 		if (!SSL_context)
 			ereport(FATAL,
diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index ff79a0d5d50..73a0b0cf078 100644
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -965,7 +965,13 @@ init_ssl_system(PGconn *conn)
 			SSL_load_error_strings();
 		}
 
-		SSL_context = SSL_CTX_new(TLSv1_method());
+		/*
+		 * We use SSLv23_method() because it can negotiate use of the highest
+		 * mutually supported protocol version, while alternatives like
+		 * TLSv1_2_method() permit only one specific version.  Note that we
+		 * don't actually allow SSL v2 or v3, only TLS protocols (see below).
+		 */
+		SSL_context = SSL_CTX_new(SSLv23_method());
 		if (!SSL_context)
 		{
 			char	   *err = SSLerrmessage();
@@ -980,6 +986,9 @@ init_ssl_system(PGconn *conn)
 			return -1;
 		}
 
+		/* Disable old protocol versions */
+		SSL_CTX_set_options(SSL_context, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
+
 		/*
 		 * Disable OpenSSL's moving-write-buffer sanity check, because it
 		 * causes unnecessary failures in nonblocking send cases.


[parent: 5b461f239eae]