[exim-cvs] TLS fixes for OpenSSL.

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Author: Exim Git Commits Mailing List
Date:  
To: exim-cvs
Subject: [exim-cvs] TLS fixes for OpenSSL.
Gitweb: http://git.exim.org/exim.git/commitdiff/c80c557026f3933b0472b13331924f8bd4ed9bf7
Commit:     c80c557026f3933b0472b13331924f8bd4ed9bf7
Parent:     dec5017e2e41bb85d559e2b35713f1e294cdde8c
Author:     Phil Pennock <pdp@???>
AuthorDate: Sat Apr 28 06:21:02 2012 -0700
Committer:  Phil Pennock <pdp@???>
CommitDate: Sat Apr 28 06:21:02 2012 -0700


    TLS fixes for OpenSSL.


    Support TLS 1.1 & 1.2
    New "openssl_options" values (all now documented).


    Set SSL_MODE_AUTO_RETRY so that OpenSSL will retry a read or write after
    TLS renegotiation, which otherwise led to messages "Got SSL error 2".
---
 doc/doc-docbook/spec.xfpt |   55 +++++++++++++++++++++++++++++++++++++++++++++
 doc/doc-txt/ChangeLog     |    5 ++++
 src/README.UPDATING       |    9 +++++++
 src/src/tls-openssl.c     |   45 +++++++++++++++++++++++++++++++-----
 4 files changed, 107 insertions(+), 7 deletions(-)


diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index c1f845e..e719855 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -14362,6 +14362,61 @@ An example:
openssl_options = -all +microsoft_big_sslv3_buffer
.endd

+Possible options may include:
+.ilist
+&`all`&
+.ilist
+&`allow_unsafe_legacy_renegotiation`&
+.ilist
+&`cipher_server_preference`&
+.ilist
+&`dont_insert_empty_fragments`&
+.ilist
+&`ephemeral_rsa`&
+.ilist
+&`legacy_server_connect`&
+.ilist
+&`microsoft_big_sslv3_buffer`&
+.ilist
+&`microsoft_sess_id_bug`&
+.ilist
+&`msie_sslv2_rsa_padding`&
+.ilist
+&`netscape_challenge_bug`&
+.ilist
+&`netscape_reuse_cipher_change_bug`&
+.ilist
+&`no_compression`&
+.ilist
+&`no_session_resumption_on_renegotiation`&
+.ilist
+&`no_sslv2`&
+.ilist
+&`no_sslv3`&
+.ilist
+&`no_ticket`&
+.ilist
+&`no_tlsv1`&
+.ilist
+&`no_tlsv1_1`&
+.ilist
+&`no_tlsv1_2`&
+.ilist
+&`single_dh_use`&
+.ilist
+&`single_ecdh_use`&
+.ilist
+&`ssleay_080_client_dh_bug`&
+.ilist
+&`sslref2_reuse_cert_type_bug`&
+.ilist
+&`tls_block_padding_bug`&
+.ilist
+&`tls_d5_bug`&
+.ilist
+&`tls_rollback_bug`&
+.endlist
+

 .option oracle_servers main "string list" unset
 .cindex "Oracle" "server list"
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 03f4469..1d31387 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -53,6 +53,11 @@ PP/13 tls_peerdn now print-escaped for spool files.
       Observed some $tls_peerdn in wild which contained \n, which resulted
       in spool file corruption.


+PP/14 TLS fixes for OpenSSL: support TLS 1.1 & 1.2; new "openssl_options"
+      values; set SSL_MODE_AUTO_RETRY so that OpenSSL will retry a read
+      or write after TLS renegotiation, which otherwise led to messages
+      "Got SSL error 2".
+


 Exim version 4.77
 -----------------
diff --git a/src/README.UPDATING b/src/README.UPDATING
index 1eb3627..9e3689d 100644
--- a/src/README.UPDATING
+++ b/src/README.UPDATING
@@ -39,6 +39,15 @@ Exim version 4.78
    the message.  No tool has been provided as we believe this is a rare
    occurence.


+ * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2. If built
+ against 1.0.1a then you will get a warning message and the
+ "openssl_options" value will not parse "no_tlsv1_1": the value changes
+ incompatibly between 1.0.1a and 1.0.1b, because the value chosen for 1.0.1a
+ is infelicitous. We advise avoiding 1.0.1a.
+
+ "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
+
+

Exim version 4.77
-----------------
diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c
index 2104711..e2e150c 100644
--- a/src/src/tls-openssl.c
+++ b/src/src/tls-openssl.c
@@ -347,6 +347,9 @@ level. */

SSL_CTX_set_info_callback(ctx, (void (*)())info_callback);

+/* Automatically re-try reads/writes after renegotiation. */
+(void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY);
+
/* Apply administrator-supplied work-arounds.
Historically we applied just one requested option,
SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we
@@ -456,6 +459,18 @@ switch (ssl->session->ssl_version)
ver = US"TLSv1";
break;

+#ifdef TLS1_1_VERSION
+ case TLS1_1_VERSION:
+ ver = US"TLSv1.1";
+ break;
+#endif
+
+#ifdef TLS1_2_VERSION
+ case TLS1_2_VERSION:
+ ver = US"TLSv1.2";
+ break;
+#endif
+
default:
ver = US"UNKNOWN";
}
@@ -873,8 +888,8 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm)
int error;
int inbytes;

-  DEBUG(D_tls) debug_printf("Calling SSL_read(%lx, %lx, %u)\n", (long)ssl,
-    (long)ssl_xfer_buffer, ssl_xfer_buffer_size);
+  DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl,
+    ssl_xfer_buffer, ssl_xfer_buffer_size);


   if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
   inbytes = SSL_read(ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size);
@@ -920,6 +935,7 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm)
     ssl_xfer_error = 1;
     return EOF;
     }
+
 #ifndef DISABLE_DKIM
   dkim_exim_verify_feed(ssl_xfer_buffer, inbytes);
 #endif
@@ -953,8 +969,8 @@ tls_read(uschar *buff, size_t len)
 int inbytes;
 int error;


-DEBUG(D_tls) debug_printf("Calling SSL_read(%lx, %lx, %u)\n", (long)ssl,
- (long)buff, (unsigned int)len);
+DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl,
+ buff, (unsigned int)len);

inbytes = SSL_read(ssl, CS buff, len);
error = SSL_get_error(ssl, inbytes);
@@ -996,10 +1012,10 @@ int outbytes;
int error;
int left = len;

-DEBUG(D_tls) debug_printf("tls_do_write(%lx, %d)\n", (long)buff, left);
+DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left);
while (left > 0)
{
- DEBUG(D_tls) debug_printf("SSL_write(SSL, %lx, %d)\n", (long)buff, left);
+ DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left);
outbytes = SSL_write(ssl, CS buff, left);
error = SSL_get_error(ssl, outbytes);
DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error);
@@ -1177,7 +1193,7 @@ all options unless explicitly for DTLS, let the administrator choose which
to apply.

This list is current as of:
- ==> 1.0.0c <== */
+ ==> 1.0.1b <== */
static struct exim_openssl_option exim_openssl_options[] = {
/* KEEP SORTED ALPHABETICALLY! */
#ifdef SSL_OP_ALL
@@ -1213,6 +1229,9 @@ static struct exim_openssl_option exim_openssl_options[] = {
#ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
{ US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG },
#endif
+#ifdef SSL_OP_NO_COMPRESSION
+ { US"no_compression", SSL_OP_NO_COMPRESSION },
+#endif
#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
{ US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION },
#endif
@@ -1228,6 +1247,17 @@ static struct exim_openssl_option exim_openssl_options[] = {
#ifdef SSL_OP_NO_TLSv1
{ US"no_tlsv1", SSL_OP_NO_TLSv1 },
#endif
+#ifdef SSL_OP_NO_TLSv1_1
+#if SSL_OP_NO_TLSv1_1 == 0x00000400L
+ /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */
+#warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
+#else
+ { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 },
+#endif
+#endif
+#ifdef SSL_OP_NO_TLSv1_2
+ { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 },
+#endif
#ifdef SSL_OP_SINGLE_DH_USE
{ US"single_dh_use", SSL_OP_SINGLE_DH_USE },
#endif
@@ -1253,6 +1283,7 @@ static struct exim_openssl_option exim_openssl_options[] = {
static int exim_openssl_options_size =
sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option);

+
static BOOL
tls_openssl_one_option_parse(uschar *name, long *value)
{