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();
+}