From 5715c21a077ee1c2fe8957cb4adcea14fd2eda6b Mon Sep 17 00:00:00 2001
From: Laurent Bercot <ska-skaware@skarnet.org>
Date: Fri, 20 Nov 2020 23:24:29 +0000
Subject:  Refactor tls code to support ucspi-tls

 That includes:
 - new architecture: the tls binary is now a child of the app
instead of the other way around
 - the sbearssl_run engine now takes a post-handshake callback.
This allows s6-tlsc and s6-tlsd to only exec into the app when
the handshake succeeds (which was already the case with libressl).
 - new binaries s6-tlsc-io and s6-tlsd-io encapsulate the crypto
code; they init and run the engine, connecting to 4 already open
fds (stdin/stdout = network, argv[1] and argv[2] = local)
 - s6-tlsc is now a simple wrapper around s6-tlsc-io
 - s6-tlsd is now a simple wrapper around s6-tlsd-io
 - new binary: s6-ucspitlsd, which is also a wrapper around
s6-tlsd-io, but differently: the parent execs the app which should
be ucspi-tls-aware, the child waits for a command from the parent
and execs into s6-tlsd-io if it receives it.
---
 src/stls/stls_server_init_and_handshake.c | 81 +++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 src/stls/stls_server_init_and_handshake.c

(limited to 'src/stls/stls_server_init_and_handshake.c')

diff --git a/src/stls/stls_server_init_and_handshake.c b/src/stls/stls_server_init_and_handshake.c
new file mode 100644
index 0000000..58d812e
--- /dev/null
+++ b/src/stls/stls_server_init_and_handshake.c
@@ -0,0 +1,81 @@
+/* ISC license. */
+
+#include <stdlib.h>
+
+#include <tls.h>
+
+#include <skalibs/strerr2.h>
+
+#include <s6-networking/stls.h>
+#include "stls-internal.h"
+
+#define diecfg(cfg, s) strerr_diefu3x(96, (s), ": ", tls_config_error(cfg))
+#define diectx(e, ctx, s) strerr_diefu3x(e, (s), ": ", tls_error(ctx))
+
+struct tls *stls_server_init_and_handshake (int const *fds, uint32_t preoptions)
+{
+  struct tls *cctx ;
+  struct tls *ctx ;
+  struct tls_config *cfg ;
+  char const *x ;
+
+  if (tls_init() < 0) strerr_diefu1sys(111, "tls_init") ;
+  cfg = tls_config_new() ;
+  if (!cfg) strerr_diefu1sys(111, "tls_config_new") ;
+
+  x = getenv("CERTFILE") ;
+  if (!x) strerr_dienotset(100, "CERTFILE") ;
+  if (tls_config_set_cert_file(cfg, x) < 0)
+    diecfg(cfg, "tls_config_set_cert_file") ;
+
+  x = getenv("KEYFILE") ;
+  if (!x) strerr_dienotset(100, "KEYFILE") ;
+  if (tls_config_set_key_file(cfg, x) < 0)
+    diecfg(cfg, "tls_config_set_key_file") ;
+
+  if (tls_config_set_ciphers(cfg, "secure") < 0)
+    diecfg(cfg, "tls_config_set_ciphers") ;
+
+  if (tls_config_set_dheparams(cfg, "auto") < 0)
+    diecfg(cfg, "tls_config_set_dheparams") ;
+
+  if (tls_config_set_ecdhecurve(cfg, "auto") < 0)
+    diecfg(cfg, "tls_config_set_ecdhecurve") ;
+
+  if (preoptions & 1)
+  {
+    x = getenv("CADIR") ;
+    if (x)
+    {
+      if (tls_config_set_ca_path(cfg, x) < 0)
+        diecfg(cfg, "tls_config_set_ca_path") ;
+    }
+    else
+    {
+      x = getenv("CAFILE") ;
+      if (x)
+      {
+        if (tls_config_set_ca_file(cfg, x) < 0)
+          diecfg(cfg, "tls_config_set_ca_file") ;
+      }
+      else strerr_dienotset(100, "CADIR or CAFILE") ;
+    }
+    if (preoptions & 2) tls_config_verify_client(cfg) ;
+    else tls_config_verify_client_optional(cfg) ;
+  }
+  else tls_config_insecure_noverifycert(cfg) ;
+
+  tls_config_set_protocols(cfg, TLS_PROTOCOLS_DEFAULT) ;
+  tls_config_prefer_ciphers_server(cfg) ;
+
+  ctx = tls_server() ;
+  if (!ctx) strerr_diefu1sys(111, "tls_server") ;
+  if (tls_configure(ctx, cfg) < 0) diectx(97, ctx, "tls_configure") ;
+  tls_config_free(cfg) ;
+  if (tls_accept_fds(ctx, &cctx, fds[0], fds[1]) < 0)
+    diectx(97, ctx, "tls_accept_fds") ;
+  tls_free(ctx) ;
+  if (tls_handshake(cctx) < 0)
+    diectx(97, cctx, "perform SSL handshake") ;
+  return cctx ;
+}
-- 
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