From 1c72c8d1260036cfd35a1827cf6b2101068ed6bd Mon Sep 17 00:00:00 2001
From: Kedar Sovani <kedars@gmail.com>
Date: Thu, 30 Nov 2017 11:35:34 +0530
Subject: [PATCH] Supports TLS with HTTP2 client

---
 components/esp-tls/esp-tls.c | 19 +++++++++++++++----
 components/esp-tls/esp-tls.h | 28 +++++++++++++++++++++++++++-
 2 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/components/esp-tls/esp-tls.c b/components/esp-tls/esp-tls.c
index 9906fdbf7..59ccd1a81 100644
--- a/components/esp-tls/esp-tls.c
+++ b/components/esp-tls/esp-tls.c
@@ -95,7 +95,7 @@ err_freeaddr:
     return -1;
 }
 
-static int create_ssl_handle(struct esp_tls *tls)
+static int create_ssl_handle(struct esp_tls *tls, const char *hostname, size_t hostlen, struct esp_tls_cfg *cfg)
 {
     int ret;
 
@@ -108,12 +108,23 @@ static int create_ssl_handle(struct esp_tls *tls)
     SSL_CTX_set_mode(ssl_ctx, SSL_MODE_AUTO_RETRY);
     SSL_CTX_set_mode(ssl_ctx, SSL_MODE_RELEASE_BUFFERS);
 #endif
+    if (cfg->alpn_protos) {
+	SSL_CTX_set_alpn_protos(ssl_ctx, cfg->alpn_protos, strlen((char *)cfg->alpn_protos));
+    }
     SSL *ssl = SSL_new(ssl_ctx);
     if (!ssl) {
         SSL_CTX_free(ssl_ctx);
         return -1;
     }
 
+    char *use_host = strndup(hostname, hostlen);
+    if (!use_host) {
+	SSL_CTX_free(ssl_ctx);
+	return -1;
+    }
+    SSL_set_tlsext_host_name(ssl, use_host);
+    free(use_host);
+
     SSL_set_fd(ssl, tls->sockfd);
     ret = SSL_connect(ssl);
     if (ret < 1) {
@@ -155,7 +166,7 @@ static ssize_t tls_write(struct esp_tls *tls, const char *data, size_t datalen)
     return SSL_write(tls->ssl, data, datalen);
 }
 
-struct esp_tls *esp_tls_conn_new(const char *hostname, int hostlen, int port, bool is_tls)
+struct esp_tls *esp_tls_conn_new(const char *hostname, int hostlen, int port, struct esp_tls_cfg *cfg)
 {
     int sockfd = esp_tcp_connect(hostname, hostlen, port);
     if (sockfd < 0) {
@@ -171,8 +182,8 @@ struct esp_tls *esp_tls_conn_new(const char *hostname, int hostlen, int port, bo
     tls->read = tcp_read;
     tls->write = tcp_write;
 
-    if (is_tls) {
-        if (create_ssl_handle(tls) != 0) {
+    if (cfg) {
+        if (create_ssl_handle(tls, hostname, hostlen, cfg) != 0) {
             esp_tls_conn_delete(tls);
             return NULL;
         }
diff --git a/components/esp-tls/esp-tls.h b/components/esp-tls/esp-tls.h
index bff2eda4d..08cc63cf2 100644
--- a/components/esp-tls/esp-tls.h
+++ b/components/esp-tls/esp-tls.h
@@ -5,6 +5,22 @@
 #include <sys/socket.h>
 #include <openssl/ssl.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct esp_tls_cfg {
+    /* If HTTP2/ALPN support is required, a list of protocols that
+     * should be negotiated. The format is length followed by protocol
+     * name.
+     * For the most common cases the following is ok:
+     * "\x02h2"
+     * - where the first '2' is the length of the protocol and
+     * - the subsequent 'h2' is the protocol name
+     */
+    const unsigned char *alpn_protos;
+};
+
 struct esp_tls {
     SSL_CTX  *ctx;
     SSL      *ssl;
@@ -13,7 +29,13 @@ struct esp_tls {
     ssize_t (*write)(struct esp_tls *tls, const char *data, size_t datalen);
 };
 
-struct esp_tls *esp_tls_conn_new(const char *hostname, int hostlen, int port, bool is_tls);
+/*
+ *
+ * cfg: If you wish to open non-TLS connection, keep this NULL. For TLS
+ * connection, a pass pointer to 'struct esp_tls_cfg'. At a minimum, this
+ * structure should be zero-initialized.
+ */
+struct esp_tls *esp_tls_conn_new(const char *hostname, int hostlen, int port, struct esp_tls_cfg *cfg);
 
 static inline ssize_t esp_tls_conn_write(struct esp_tls *tls, const char *data, size_t datalen)
 {
@@ -27,4 +49,8 @@ static inline ssize_t esp_tls_conn_read(struct esp_tls *tls, char *data, size_t
 
 void esp_tls_conn_delete(struct esp_tls *tls);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* ! _ESP_TLS_H_ */