Merge branch 'curves_list'

5 files changed, 102 insertions, 3 deletions

diff --git a/doc/luaossl.pdf b/doc/luaossl.pdf
index 25c58ca..81142cb 100644
--- a/doc/luaossl.pdf
+++ b/doc/luaossl.pdf
diff --git a/doc/luaossl.tex b/doc/luaossl.tex
index 5e19e66..7bb85df 100644
--- a/doc/luaossl.tex
+++ b/doc/luaossl.tex
@@ -933,11 +933,17 @@ Sets the private key \module{openssl.pkey} object $key$ for use during SSL conne
 
 Sets the allowed public key and private key algorithm(s). The string format is documented in the \href{http://www.openssl.org/docs/apps/ciphers.html#CIPHER_LIST_FORMAT}{OpenSSL ciphers(1) utility documentation}.
 
+\subsubsection[\fn{context:setCurvesList}]{\fn{context:setCurvesList($string$ [, ...])}}
+
+Sets the supported curves. The string format is a list of colon separated curve names similar to \texttt{ctx:setCipherList(...)}. A list of supported curves can be found by running \texttt{openssl ecparam -list\_curves}.
+
+\emph{Only supported since OpenSSL 1.0.2.}
+
 \subsubsection[\fn{context:setEphemeralKey}]{\fn{context:setEphemeralKey($key$)}}
 
 Sets \module{openssl.pkey} object $key$ as the ephemeral key during key exchanges which use that particular key type. Typically $key$ will be either a Diffie-Hellman or Elliptic Curve key.
 
-\emph{In order to configure an SSL server to support an ephemeral key exchange cipher suite (i.e. DHE-* and ECDHE-*), the application must explicitly set the ephemeral keys. Simply enabling the cipher suite is not sufficient. The application can statically generate Diffie-Hellman public key parameters, and many servers ship with such a key compiled into the software. Elliptic curve keys are necessarily static, and instantiated by curve name\footnote{\href{http://en.wikipedia.org/w/index.php?title=Comparison\_of\_TLS\_implementations&oldid=629779090\#Supported\_elliptic\_curves}{According to Wikipedia} the most widely supported curve is prime256v1, so to enable ECDHE-* applications can simply do \texttt{ctx:setEphemeralKey(pkey.new\{ type = ``EC'', curve = ``prime256v1'' \})}. To achieve Perfect Forward Secrecy for ECDHE-*, applications must also do \texttt{ctx:setOptions(context.OP\_SINGLE\_ECDH\_USE)}. The \texttt{ctx} object must then be used to configure each SSL session, such as by passing it to \fn{cqueues.socket:starttls()}.}.}
+\emph{In order to configure an SSL server to support an ephemeral key exchange cipher suite (i.e. DHE-* and ECDHE-*), the application must explicitly set the ephemeral keys. Simply enabling the cipher suite is not sufficient. The application can statically generate Diffie-Hellman public key parameters, and many servers ship with such a key compiled into the software. Elliptic curve keys are necessarily static, and instantiated by curve name\footnote{OpenSSL < 1.0.2 only supports a single curve, \href{http://en.wikipedia.org/w/index.php?title=Comparison\_of\_TLS\_implementations&oldid=629779090\#Supported\_elliptic\_curves}{according to Wikipedia} the most widely supported curve is prime256v1, so to enable ECDHE-*, applications can simply do \texttt{ctx:setEphemeralKey(pkey.new\{ type = ``EC'', curve = ``prime256v1'' \})}. To achieve Perfect Forward Secrecy for ECDHE-*, applications must also do \texttt{ctx:setOptions(context.OP\_SINGLE\_ECDH\_USE)}. The \texttt{ctx} object must then be used to configure each SSL session, such as by passing it to \fn{cqueues.socket:starttls()}.}.}
 
 \emph{In addition, to attain Perfect Forward Secrecy the options \texttt{OP\_SINGLE\_DH\_USE} and \texttt{OP\_SINGLE\_ECDH\_USE} must be set so that OpenSSL discards and regenerates the secret keying parameters for each key exchange.}
 
@@ -1070,6 +1076,12 @@ TLS1\_2\_VERSION & 16-bit TLSv1.2 identifier (0x0303).  \\
 
 Returns the SSL/TLS version supported by the client, which should be greater than or equal to the negotiated version. See \fn{ssl:getVersion}.
 
+\subsubsection[\fn{ssl:setCurvesList}]{\fn{ssl:setCurvesList($string$ [, ...])}}
+
+Sets the supported curves for this SSL connection instance. See \fn{openssl.ssl.context:setCurvesList}.
+
+\emph{Only supported since OpenSSL 1.0.2.}
+
 \subsubsection[\fn{ssl:getAlpnSelected}]{\fn{ssl:getAlpnSelected()}}
 
 Returns the negotiated ALPN protocol as a string.
diff --git a/src/openssl.c b/src/openssl.c
index ac053fd..a3e5637 100644
--- a/src/openssl.c
+++ b/src/openssl.c
@@ -253,6 +253,14 @@
 #define HAVE_SSL_CTX_GET0_PARAM OPENSSL_PREREQ(1,0,2)
 #endif
 
+#ifndef HAVE_SSL_CTX_SET_CURVES_LIST
+#define HAVE_SSL_CTX_SET_CURVES_LIST (OPENSSL_PREREQ(1,0,2) || LIBRESSL_PREREQ(2,5,1))
+#endif
+
+#ifndef HAVE_SSL_CTX_SET_ECDH_AUTO
+#define HAVE_SSL_CTX_SET_ECDH_AUTO ((OPENSSL_PREREQ(1,0,2) && !OPENSSL_PREREQ(1,1,0)) || LIBRESSL_PREREQ(2,1,2))
+#endif
+
 #ifndef HAVE_SSL_CTX_SET_ALPN_PROTOS
 #define HAVE_SSL_CTX_SET_ALPN_PROTOS (OPENSSL_PREREQ(1,0,2) || LIBRESSL_PREREQ(2,1,3))
 #endif
@@ -297,6 +305,10 @@
 #define HAVE_SSL_SET_ALPN_PROTOS HAVE_SSL_CTX_SET_ALPN_PROTOS
 #endif
 
+#ifndef HAVE_SSL_SET_CURVES_LIST
+#define HAVE_SSL_SET_CURVES_LIST (OPENSSL_PREREQ(1,0,2) || LIBRESSL_PREREQ(2,5,1))
+#endif
+
 #ifndef HAVE_SSL_SET1_PARAM
 #define HAVE_SSL_SET1_PARAM OPENSSL_PREREQ(1,0,2)
 #endif
@@ -7824,6 +7836,15 @@ static int sx_new(lua_State *L) {
 
         SSL_CTX_set_options(*ud, options);
 
+#if HAVE_SSL_CTX_SET_ECDH_AUTO
+        /* OpenSSL 1.0.2 introduced SSL_CTX_set_ecdh_auto to automatically select
+         * from the curves set via SSL_CTX_set1_curves_list. However as of OpenSSL
+         * 1.1.0, the functionality was turned on permanently and the option
+         * removed. */
+        if (!SSL_CTX_set_ecdh_auto(*ud, 1))
+                return auxL_error(L, auxL_EOPENSSL, "ssl.context.new");
+#endif
+
         return 1;
 } /* sx_new() */
 
@@ -7999,6 +8020,21 @@ static int sx_setCipherList(lua_State *L) {
 } /* sx_setCipherList() */
 
 
+#if HAVE_SSL_CTX_SET_CURVES_LIST
+static int sx_setCurvesList(lua_State *L) {
+        SSL_CTX *ctx = checksimple(L, 1, SSL_CTX_CLASS);
+        const char *curves = luaL_checkstring(L, 2);
+
+        if (!SSL_CTX_set1_curves_list(ctx, curves))
+                return auxL_error(L, auxL_EOPENSSL, "ssl.context:setCurvesList");
+
+        lua_pushboolean(L, 1);
+
+        return 1;
+} /* sx_setCurvesList() */
+#endif
+
+
 static int sx_setEphemeralKey(lua_State *L) {
         SSL_CTX *ctx = checksimple(L, 1, SSL_CTX_CLASS);
         EVP_PKEY *key = checksimple(L, 2, PKEY_CLASS);
@@ -8303,6 +8339,9 @@ static const auxL_Reg sx_methods[] = {
         { "setCertificate",   &sx_setCertificate },
         { "setPrivateKey",    &sx_setPrivateKey },
         { "setCipherList",    &sx_setCipherList },
+#if HAVE_SSL_CTX_SET_CURVES_LIST
+        { "setCurvesList",    &sx_setCurvesList },
+#endif
         { "setEphemeralKey",  &sx_setEphemeralKey },
 #if HAVE_SSL_CTX_SET_ALPN_PROTOS
         { "setAlpnProtos",    &sx_setAlpnProtos },
@@ -8627,6 +8666,21 @@ static int ssl_getCipherInfo(lua_State *L) {
 } /* ssl_getCipherInfo() */
 
 
+#if HAVE_SSL_SET_CURVES_LIST
+static int ssl_setCurvesList(lua_State *L) {
+        SSL *ssl = checksimple(L, 1, SSL_CLASS);
+        const char *curves = luaL_checkstring(L, 2);
+
+        if (!SSL_set1_curves_list(ssl, curves))
+                return auxL_error(L, auxL_EOPENSSL, "ssl:setCurvesList");
+
+        lua_pushboolean(L, 1);
+
+        return 1;
+} /* ssl_setCurvesList() */
+#endif
+
+
 static int ssl_getHostName(lua_State *L) {
         SSL *ssl = checksimple(L, 1, SSL_CLASS);
         const char *host;
@@ -8881,6 +8935,9 @@ static const auxL_Reg ssl_methods[] = {
         { "getPeerCertificate", &ssl_getPeerCertificate },
         { "getPeerChain",     &ssl_getPeerChain },
         { "getCipherInfo",    &ssl_getCipherInfo },
+#if HAVE_SSL_SET_CURVES_LIST
+        { "setCurvesList",    &ssl_setCurvesList },
+#endif
         { "getHostName",      &ssl_getHostName },
         { "setHostName",      &ssl_setHostName },
         { "getVersion",       &ssl_getVersion },
diff --git a/src/openssl.ssl.context.lua b/src/openssl.ssl.context.lua
index 2098b54..3263fb1 100644
--- a/src/openssl.ssl.context.lua
+++ b/src/openssl.ssl.context.lua
@@ -13,4 +13,18 @@ local setCipherList; setCipherList = ctx.interpose("setCipherList", function (se
         return setCipherList(self, ciphers)
 end)
 
+-- Allow passing a vararg of curves, or an array
+local setCurvesList = ctx.interpose("setCurvesList", nil)
+if setCurvesList then
+        ctx.interpose("setCurvesList", function (self, curves, ...)
+                if (...) then
+                        local curves_t = pack(curves, ...)
+                        curves = table.concat(curves_t, ":", 1, curves_t.n)
+                elseif type(curves) == "table" then
+                        curves = table.concat(curves, ":")
+                end
+                return setCurvesList(self, curves)
+        end)
+end
+
 return ctx
diff --git a/src/openssl.ssl.lua b/src/openssl.ssl.lua
index 3c348f6..bf90f29 100644
--- a/src/openssl.ssl.lua
+++ b/src/openssl.ssl.lua
@@ -1,3 +1,19 @@
-local ctx = require"_openssl.ssl"
+local ssl = require"_openssl.ssl"
 
-return ctx
+local pack = table.pack or function(...) return { n = select("#", ...); ... } end
+
+-- Allow passing a vararg of curves, or an array
+local setCurvesList = ssl.interpose("setCurvesList", nil)
+if setCurvesList then
+        ssl.interpose("setCurvesList", function (self, curves, ...)
+                if (...) then
+                        local curves_t = pack(curves, ...)
+                        curves = table.concat(curves_t, ":", 1, curves_t.n)
+                elseif type(curves) == "table" then
+                        curves = table.concat(curves, ":")
+                end
+                return setCurvesList(self, curves)
+        end)
+end
+
+return ssl