Merge remote-tracking branch 'public/pr/1957' into mbedtls-2.1
diff --git a/ChangeLog b/ChangeLog
index cd00394..19180e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -15,6 +15,11 @@
    * Fix a miscalculation of the maximum record expansion in
      mbedtls_ssl_get_record_expansion() in case of CBC ciphersuites
      in (D)TLS versions 1.1 or higher. Fixes #1914.
+   * Fix a bug that caused SSL/TLS clients to incorrectly abort the handshake
+     with TLS versions 1.1 and earlier when the server requested authentication
+     without providing a list of CAs. This was due to an overly strict bounds
+     check in parsing the CertificateRequest message,
+     introduced in Mbed TLS 2.12.0. Fixes #1954.
 
 = mbed TLS 2.1.14 branch released 2018-07-25
 
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 916a29c..4d8288e 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2504,7 +2504,7 @@
      * therefore the buffer length at this point must be greater than that
      * regardless of the actual code path.
      */
-    if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n )
+    if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
         return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 9a432fb..ec9e75a 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -656,6 +656,22 @@
             -S "SSL - None of the common ciphersuites is usable" \
             -S "SSL - The server has no ciphersuites in common"
 
+# Test empty CA list in CertificateRequest in TLS 1.1 and earlier
+
+requires_gnutls
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_1
+run_test    "CertificateRequest with empty CA list, TLS 1.1 (GnuTLS server)" \
+            "$G_SRV"\
+            "$P_CLI force_version=tls1_1" \
+            0
+
+requires_gnutls
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1
+run_test    "CertificateRequest with empty CA list, TLS 1.0 (GnuTLS server)" \
+            "$G_SRV"\
+            "$P_CLI force_version=tls1" \
+            0
+
 # Tests for SHA-1 support
 
 requires_config_disabled MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES