client: remove NPN support (Ruby 2.3.0 will be released soon)

3 files changed, 4 insertions, 11 deletions

diff --git a/.gitignore b/.gitignore
index 6c58a7a..a456d3f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 /.bundle/
 /.yardoc
+/.ruby-version
 /Gemfile.lock
 /_yardoc/
 /coverage/
diff --git a/README.md b/README.md
index bbf7575..b05e22d 100644
--- a/README.md
+++ b/README.md
@@ -63,7 +63,7 @@ If the server does't support HTTP/2, `Plum::Client` tries to use HTTP/1.x instea
    +-----------------+
             v "https"
    +-----------------+
-   | ALPN(/NPN)      | failed
+   | ALPN            | failed
    | negotiation     |-------> HTTP/1.x
    +-----------------+
             | "h2"
diff --git a/lib/plum/client.rb b/lib/plum/client.rb
index 103d938..020b372 100644
--- a/lib/plum/client.rb
+++ b/lib/plum/client.rb
@@ -143,8 +143,7 @@ module Plum
         @socket.connect
         @socket.post_connection_check(@config[:hostname]) if ctx.verify_mode != OpenSSL::SSL::VERIFY_NONE
 
-        @socket.respond_to?(:alpn_protocol) && @socket.alpn_protocol == "h2" ||
-          @socket.respond_to?(:npn_protocol) && @socket.npn_protocol == "h2"
+        @socket.alpn_protocol == "h2"
       end
     end
 
@@ -176,14 +175,7 @@ module Plum
       ctx.cert_store = cert_store
       if @config[:http2]
         ctx.ciphers = "ALL:!" + SSLSocketServerConnection::CIPHER_BLACKLIST.join(":!")
-        if ctx.respond_to?(:alpn_protocols)
-          ctx.alpn_protocols = ["h2", "http/1.1"]
-        end
-        if ctx.respond_to?(:npn_select_cb) # TODO: RFC 7540 does not define protocol negotiation with NPN
-          ctx.npn_select_cb = -> protocols {
-            protocols.include?("h2") ? "h2" : protocols.first
-         }
-        end
+        ctx.alpn_protocols = ["h2", "http/1.1"]
       end
       ctx
     end