http09: disable HTTP/0.9 by default in both tool and library

As the plan has been laid out in DEPRECATED. Update docs accordingly and
verify in test 1174. Now requires the option to be set to allow HTTP/0.9
responses.

Closes #4191

12 files changed, 59 insertions, 30 deletions

diff --git a/docs/DEPRECATE.md b/docs/DEPRECATE.md
index f04f0eeaa..4f4ef8ab6 100644
--- a/docs/DEPRECATE.md
+++ b/docs/DEPRECATE.md
@@ -5,21 +5,6 @@ email the curl-library mailing list as soon as possible and explain to us why
 this is a problem for you and how your use case can't be satisfied properly
 using a work around.
 
-## HTTP/0.9
-
-Supporting this is non-obvious and might even come as a surprise to some
-users. Potentially even being a security risk in some cases.
-
-### State
-
-curl 7.64.0 introduces options to disable/enable support for this protocol
-version. The default remains supported for now.
-
-### Removal
-
-The support for HTTP/0.9 will be switched to disabled by default in 6 months,
-in the September 2019 release (possibly called curl 7.68.0).
-
 ## PolarSSL
 
 The polarssl TLS library has not had an update in over three years. The last
diff --git a/docs/cmdline-opts/http0.9.d b/docs/cmdline-opts/http0.9.d
index 33fe72d18..7e783f696 100644
--- a/docs/cmdline-opts/http0.9.d
+++ b/docs/cmdline-opts/http0.9.d
@@ -10,5 +10,4 @@ HTTP/0.9 is a completely headerless response and therefore you can also
 connect with this to non-HTTP servers and still get a response since curl will
 simply transparently downgrade - if allowed.
 
-A future curl version will deny continuing if the response isn't at least
-HTTP/1.0 unless this option is used.
+Since curl 7.66.0, HTTP/0.9 is disabled by default.
diff --git a/docs/libcurl/opts/CURLOPT_HTTP09_ALLOWED.3 b/docs/libcurl/opts/CURLOPT_HTTP09_ALLOWED.3
index 3fa44993a..25520150f 100644
--- a/docs/libcurl/opts/CURLOPT_HTTP09_ALLOWED.3
+++ b/docs/libcurl/opts/CURLOPT_HTTP09_ALLOWED.3
@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -31,12 +31,12 @@ CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTP09_ALLOWED, long allowed);
 Pass the long argument \fIallowed\fP set to 1L to allow HTTP/0.9 responses.
 
 A HTTP/0.9 response is a server response entirely without headers and only a
-body, while you can connect to lots of random TCP services and still get a
-response that curl might consider to be HTTP/0.9.
+body. You can connect to lots of random TCP services and still get a response
+that curl might consider to be HTTP/0.9!
 .SH DEFAULT
-curl allows HTTP/0.9 responses by default.
+curl allowed HTTP/0.9 responses by default before 7.66.0
 
-A future curl version will require this option to be set to allow HTTP/0.9
+Since 7.66.0, libcurl requires this option set to 1L to allow HTTP/0.9
 responses.
 .SH PROTOCOLS
 HTTP
diff --git a/lib/url.c b/lib/url.c
index 13d015753..05fc0e50e 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -546,7 +546,7 @@ CURLcode Curl_init_userdefined(struct Curl_easy *data)
   set->upkeep_interval_ms = CURL_UPKEEP_INTERVAL_DEFAULT;
   set->maxconnects = DEFAULT_CONNCACHE_SIZE; /* for easy handles */
   set->maxage_conn = 118;
-  set->http09_allowed = TRUE;
+  set->http09_allowed = FALSE;
   set->httpversion =
 #ifdef USE_NGHTTP2
     CURL_HTTP_VERSION_2TLS
diff --git a/src/tool_cfgable.c b/src/tool_cfgable.c
index 7d178e47c..76febc9c9 100644
--- a/src/tool_cfgable.c
+++ b/src/tool_cfgable.c
@@ -43,7 +43,7 @@ void config_init(struct OperationConfig* config)
   config->proto_default = NULL;
   config->tcp_nodelay = TRUE; /* enabled by default */
   config->happy_eyeballs_timeout_ms = CURL_HET_DEFAULT;
-  config->http09_allowed = TRUE;
+  config->http09_allowed = FALSE;
 }
 
 static void free_config_fields(struct OperationConfig *config)
diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index 3ed4a03e4..6d19ed3c9 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -129,7 +129,7 @@ test1136 test1137 test1138 test1139 test1140 test1141 test1142 test1143 \
 test1144 test1145 test1146 test1147 test1148 test1149 test1150 test1151 \
 test1152 test1153 test1154 test1155 test1156 test1157 test1158 test1159 \
 test1160 test1161 test1162 test1163 test1164 test1165 \
-test1170 test1171 test1172 test1173 \
+test1170 test1171 test1172 test1173 test1174 \
 \
 test1200 test1201 test1202 test1203 test1204 test1205 test1206 test1207 \
 test1208 test1209 test1210 test1211 test1212 test1213 test1214 test1215 \
diff --git a/tests/data/test1174 b/tests/data/test1174
new file mode 100644
index 000000000..b316fde8c
--- /dev/null
+++ b/tests/data/test1174
@@ -0,0 +1,50 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP/0.9
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data>
+-foo- swsclose
+</data>
+<datacheck>
+</datacheck>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+</server>
+ <name>
+HTTP/0.9 GET response denied by default
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/1174
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol>
+GET /1174 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+

+</protocol>
+# unsupported protocol
+<errorcode>
+1
+</errorcode>
+</verify>
+</testcase>
diff --git a/tests/data/test1401 b/tests/data/test1401
index 647f036f4..ec3b25cc9 100644
--- a/tests/data/test1401
+++ b/tests/data/test1401
@@ -88,7 +88,6 @@ int main(int argc, char *argv[])
   curl_easy_setopt(hnd, CURLOPT_HTTPHEADER, slist1);
   curl_easy_setopt(hnd, CURLOPT_USERAGENT, "MyUA");
   curl_easy_setopt(hnd, CURLOPT_MAXREDIRS, 50L);
-  curl_easy_setopt(hnd, CURLOPT_HTTP09_ALLOWED, 1L);
   curl_easy_setopt(hnd, CURLOPT_COOKIE, "chocolate=chip");
   curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
   curl_easy_setopt(hnd, CURLOPT_TCP_KEEPALIVE, 1L);
diff --git a/tests/data/test1402 b/tests/data/test1402
index b9f52f2e8..bf7eb7b82 100644
--- a/tests/data/test1402
+++ b/tests/data/test1402
@@ -80,7 +80,6 @@ int main(int argc, char *argv[])
   curl_easy_setopt(hnd, CURLOPT_POSTFIELDSIZE_LARGE, (curl_off_t)16);
   curl_easy_setopt(hnd, CURLOPT_USERAGENT, "stripped");
   curl_easy_setopt(hnd, CURLOPT_MAXREDIRS, 50L);
-  curl_easy_setopt(hnd, CURLOPT_HTTP09_ALLOWED, 1L);
   curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
   curl_easy_setopt(hnd, CURLOPT_TCP_KEEPALIVE, 1L);
 
diff --git a/tests/data/test1403 b/tests/data/test1403
index db13081b0..731d274b3 100644
--- a/tests/data/test1403
+++ b/tests/data/test1403
@@ -75,7 +75,6 @@ int main(int argc, char *argv[])
   curl_easy_setopt(hnd, CURLOPT_URL, "http://%HOSTIP:%HTTPPORT/we/want/1403?foo=bar&baz=quux");
   curl_easy_setopt(hnd, CURLOPT_USERAGENT, "stripped");
   curl_easy_setopt(hnd, CURLOPT_MAXREDIRS, 50L);
-  curl_easy_setopt(hnd, CURLOPT_HTTP09_ALLOWED, 1L);
   curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
   curl_easy_setopt(hnd, CURLOPT_TCP_KEEPALIVE, 1L);
 
diff --git a/tests/data/test1404 b/tests/data/test1404
index e976f0b38..d3c66a9d5 100644
--- a/tests/data/test1404
+++ b/tests/data/test1404
@@ -146,7 +146,6 @@ int main(int argc, char *argv[])
   curl_easy_setopt(hnd, CURLOPT_MIMEPOST, mime1);
   curl_easy_setopt(hnd, CURLOPT_USERAGENT, "stripped");
   curl_easy_setopt(hnd, CURLOPT_MAXREDIRS, 50L);
-  curl_easy_setopt(hnd, CURLOPT_HTTP09_ALLOWED, 1L);
   curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
   curl_easy_setopt(hnd, CURLOPT_TCP_KEEPALIVE, 1L);
 
diff --git a/tests/data/test1420 b/tests/data/test1420
index ebd45ff84..03c4584d5 100644
--- a/tests/data/test1420
+++ b/tests/data/test1420
@@ -66,7 +66,6 @@ int main(int argc, char *argv[])
   curl_easy_setopt(hnd, CURLOPT_BUFFERSIZE, 102400L);
   curl_easy_setopt(hnd, CURLOPT_URL, "imap://%HOSTIP:%IMAPPORT/1420/;MAILINDEX=1");
   curl_easy_setopt(hnd, CURLOPT_USERPWD, "user:secret");
-  curl_easy_setopt(hnd, CURLOPT_HTTP09_ALLOWED, 1L);
   curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
   curl_easy_setopt(hnd, CURLOPT_TCP_KEEPALIVE, 1L);