[PATCH] GlobalProtect: always set clientos=Windows in relevant requests, regardless of actual OS

[Daniel Lenski]

I've tried, whenever possible not to lie to the server about the client
configuration. However, there are now multiple cases where a GlobalProtect
server responds with a misleading error when the `ssl-vpn/login.esp` request doesn't
contain the exact, magic value of `clientos=Windows`.

* https://github.com/dlenski/openconnect/issues/86
("Assign private IP address failed" unless `clientos=Windows` in `ssl-vpn/login.esp` request)

* https://github.com/dlenski/openconnect/issues/116
("Invalid username or password" unless `clientos=Windows` in `ssl-vpn/login.esp` request)

These cases are very difficult to debug because they seem to be suggesting totally unrelated
errors.

For reliability, this patch makes openconnect always specify `clientos=Windows` in relevant
requests, regardless of the actual `vpninfo->platname`. (The `vpninfo->platname` value can
still be sent in the "free-form" `os-version` field, as far as I can tell.)

Signed-off-by: Daniel Lenski <***@gmail.com>
---
auth-globalprotect.c | 7 ++-----
gpst.c | 6 +-----
2 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/auth-globalprotect.c b/auth-globalprotect.c
index 5c4dfe7..5b2d3ec 100644
--- a/auth-globalprotect.c
+++ b/auth-globalprotect.c
@@ -362,11 +362,8 @@ static int gpst_login(struct openconnect_info *vpninfo, int portal, char *pw_or_

/* submit gateway login (ssl-vpn/login.esp) or portal config (global-protect/getconfig.esp) request */
buf_truncate(request_body);
- buf_append(request_body, "jnlpReady=jnlpReady&ok=Login&direct=yes&clientVer=4100&prot=https:");
- if (!strcmp(vpninfo->platname, "win"))
- append_opt(request_body, "clientos", "Windows");
- else
- append_opt(request_body, "clientos", vpninfo->platname);
+ buf_append(request_body, "jnlpReady=jnlpReady&ok=Login&direct=yes&clientVer=4100&prot=https:&clientos=Windows");
+ append_opt(request_body, "os-version", vpninfo->platname);
append_opt(request_body, "server", vpninfo->hostname);
append_opt(request_body, "computer", vpninfo->localname);
if (vpninfo->ip_info.addr)
diff --git a/gpst.c b/gpst.c
index 9742fe1..b064a3e 100644
--- a/gpst.c
+++ b/gpst.c
@@ -590,12 +590,8 @@ static int gpst_get_config(struct openconnect_info *vpninfo)
char *xml_buf=NULL;

/* submit getconfig request */
- buf_append(request_body, "client-type=1&protocol-version=p1&app-version=3.0.1-10");
+ buf_append(request_body, "client-type=1&protocol-version=p1&app-version=3.0.1-10&clientos=Windows");
append_opt(request_body, "os-version", vpninfo->platname);
- if (!strcmp(vpninfo->platname, "win"))
- append_opt(request_body, "clientos", "Windows");
- else
- append_opt(request_body, "clientos", vpninfo->platname);
append_opt(request_body, "hmac-algo", "sha1,md5");
append_opt(request_body, "enc-algo", "aes-128-cbc,aes-256-cbc");
if (old_addr) {