Refactor the sha1 digest into its own function, and do not use sprintf

louloulibs/xmpp/auth.cpp

@@ -0,0 +1,21 @@
+#include <xmpp/auth.hpp>
+
+#include <utils/sha1.hpp>
+
+#include <iomanip>
+#include <sstream>
+
+std::string get_handshake_digest(const std::string& stream_id, const std::string& secret)
+{
+  sha1nfo sha1;
+  sha1_init(&sha1);
+  sha1_write(&sha1, stream_id.data(), stream_id.size());
+  sha1_write(&sha1, secret.data(), secret.size());
+  const uint8_t* result = sha1_result(&sha1);
+
+  std::ostringstream digest;
+  for (int i = 0; i < HASH_LENGTH; i++)
+    digest << std::hex << std::setfill('0') << std::setw(2) << static_cast<int>(result[i]);
+
+  return digest.str();
+}

louloulibs/xmpp/auth.hpp

@@ -0,0 +1,6 @@
+#pragma once
+
+#include <string>
+
+std::string get_handshake_digest(const std::string& stream_id, const std::string& secret);
+

louloulibs/xmpp/xmpp_component.cpp

@@ -5,15 +5,14 @@
 
 #include <xmpp/xmpp_component.hpp>
 #include <config/config.hpp>
-#include <xmpp/jid.hpp>
-#include <utils/sha1.hpp>
 #include <utils/time.hpp>
+#include <xmpp/auth.hpp>
+#include <xmpp/jid.hpp>
 
 #include <stdexcept>
 #include <iostream>
 #include <set>
 
-#include <stdio.h>
 #include <uuid/uuid.h>
 
 #include <cstdlib>
@@ -139,17 +138,7 @@ void XmppComponent::on_remote_stream_open(const XmlNode& node)
     }
 
   // Try to authenticate
-  char digest[HASH_LENGTH * 2 + 1];
+  auto data = "<handshake xmlns='" COMPONENT_NS "'>"s + get_handshake_digest(this->stream_id, this->secret) + "</handshake>";
-  sha1nfo sha1;
-  sha1_init(&sha1);
-  sha1_write(&sha1, this->stream_id.data(), this->stream_id.size());
-  sha1_write(&sha1, this->secret.data(),  this->secret.size());
-  const uint8_t* result = sha1_result(&sha1);
-  for (int i=0; i < HASH_LENGTH; i++)
-    sprintf(digest + (i*2), "%02x", result[i]);
-  digest[HASH_LENGTH * 2] = '\0';
-
-  auto data = "<handshake xmlns='" COMPONENT_NS "'>"s + digest + "</handshake>";
   log_debug("XMPP SENDING: ", data);
   this->send_data(std::move(data));
 }

tests/xmpp.cpp

@@ -1,6 +1,7 @@
 #include "catch.hpp"
 
 #include <xmpp/xmpp_parser.hpp>
+#include <xmpp/auth.hpp>
 
 TEST_CASE("Test basic XML parsing")
 {
@@ -45,3 +46,9 @@ TEST_CASE("XML escape")
   const std::string unescaped = "'coucou'<cc>/&\"gaga\"";
   CHECK(xml_escape(unescaped) == "&apos;coucou&apos;&lt;cc&gt;/&amp;&quot;gaga&quot;");
 }
+
+TEST_CASE("handshake_digest")
+{
+  const auto res = get_handshake_digest("id1234", "S4CR3T");
+  CHECK(res == "c92901b5d376ad56269914da0cce3aab976847df");
+}