1 files changed, 153 insertions, 0 deletions
diff --git a/src/xmpp/jid.cpp b/src/xmpp/jid.cpp
new file mode 100644
index 0000000..0751387
--- /dev/null
+++ b/src/xmpp/jid.cpp
@@ -0,0 +1,153 @@
+#include <xmpp/jid.hpp>
+#include <algorithm>
+#include <cstring>
+#include <map>
+
+#include <biboumi.h>
+#ifdef LIBIDN_FOUND
+ #include <stringprep.h>
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ #include <netdb.h>
+ #include <utils/scopeguard.hpp>
+ #include <set>
+#endif
+
+#include <logger/logger.hpp>
+
+Jid::Jid(const std::string& jid)
+{
+  std::string::size_type slash = jid.find('/');
+  if (slash != std::string::npos)
+    {
+      this->resource = jid.substr(slash + 1);
+    }
+
+  std::string::size_type at = jid.find('@');
+  if (at != std::string::npos && at < slash)
+    {
+      this->local = jid.substr(0, at);
+      at++;
+    }
+  else
+    at = 0;
+
+  this->domain = jid.substr(at, slash - at);
+}
+
+static constexpr size_t max_jid_part_len = 1023;
+
+std::string jidprep(const std::string& original)
+{
+#ifdef LIBIDN_FOUND
+  using CacheType = std::map<std::string, std::string>;
+  static CacheType cache;
+  std::pair<CacheType::iterator, bool> cached = cache.insert({original, {}});
+  if (std::get<1>(cached) == false)
+    { // Insertion failed: the result is already in the cache, return it
+      return std::get<0>(cached)->second;
+    }
+
+  const std::string error_msg("Failed to convert " + original + " into a valid JID:");
+  Jid jid(original);
+
+  char local[max_jid_part_len] = {};
+  memcpy(local, jid.local.data(), std::min(max_jid_part_len, jid.local.size()));
+  Stringprep_rc rc = static_cast<Stringprep_rc>(::stringprep(local, max_jid_part_len,
+                     static_cast<Stringprep_profile_flags>(0), stringprep_xmpp_nodeprep));
+  if (rc != STRINGPREP_OK)
+  {
+    log_error(error_msg + stringprep_strerror(rc));
+    return "";
+  }
+
+  char domain[max_jid_part_len] = {};
+  memcpy(domain, jid.domain.data(), std::min(max_jid_part_len, jid.domain.size()));
+
+  {
+    // Using getaddrinfo, check if the domain part is a valid IPv4 (then use
+    // it as is), or IPv6 (surround it with []), or a domain name (run
+    // nameprep)
+    struct addrinfo hints;
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_flags = AI_NUMERICHOST;
+    hints.ai_family = AF_UNSPEC;
+
+    struct addrinfo* addr_res = nullptr;
+    const auto ret = ::getaddrinfo(domain, nullptr, &hints, &addr_res);
+    auto addrinfo_deleter = utils::make_scope_guard([addr_res] { if (addr_res) freeaddrinfo(addr_res); });
+    if (ret || !addr_res || (addr_res->ai_family != AF_INET && addr_res->ai_family != AF_INET6))
+      { // Not an IP, run nameprep on it
+        rc = static_cast<Stringprep_rc>(::stringprep(domain, max_jid_part_len,
+                                                     static_cast<Stringprep_profile_flags>(0), stringprep_nameprep));
+        if (rc != STRINGPREP_OK)
+          {
+            log_error(error_msg + stringprep_strerror(rc));
+            return "";
+          }
+
+        // Make sure it contains only allowed characters
+        using std::begin;
+        using std::end;
+        char* domain_end = domain + ::strlen(domain);
+        std::replace_if(std::begin(domain), domain + ::strlen(domain),
+                        [](const char c) -> bool
+                        {
+                          return !((c >= 'a' && c <= 'z') || c == '-' ||
+                                   (c >= '0' && c <= '9') || c == '.');
+                        }, '-');
+        // Make sure there are no doubled - or .
+        std::set<char> special_chars{'-', '.'};
+        domain_end = std::unique(begin(domain), domain + ::strlen(domain), [&special_chars](const char& a, const char& b) -> bool
+        {
+          return special_chars.count(a) && special_chars.count(b);
+        });
+        // remove leading and trailing -. if any
+        if (domain_end != domain && special_chars.count(*(domain_end - 1)))
+          --domain_end;
+        if (domain_end != domain && special_chars.count(domain[0]))
+          {
+            std::memmove(domain, domain + 1, domain_end - domain + 1);
+            --domain_end;
+          }
+        // And if the final result is an empty string, return a dummy hostname
+        if (domain_end == domain)
+          ::strcpy(domain, "empty");
+        else
+          *domain_end = '\0';
+      }
+    else if (addr_res->ai_family == AF_INET6)
+      { // IPv6, surround it with []. The length is always enough:
+        // the longest possible IPv6 is way shorter than max_jid_part_len
+        ::memmove(domain + 1, domain, jid.domain.size());
+        domain[0] = '[';
+        domain[jid.domain.size() + 1] = ']';
+      }
+  }
+
+
+  // If there is no resource, stop here
+  if (jid.resource.empty())
+    {
+      std::get<0>(cached)->second = std::string(local) + "@" + domain;
+      return std::get<0>(cached)->second;
+    }
+
+  // Otherwise, also process the resource part
+  char resource[max_jid_part_len] = {};
+  memcpy(resource, jid.resource.data(), std::min(max_jid_part_len, jid.resource.size()));
+  rc = static_cast<Stringprep_rc>(::stringprep(resource, max_jid_part_len,
+       static_cast<Stringprep_profile_flags>(0), stringprep_xmpp_resourceprep));
+  if (rc != STRINGPREP_OK)
+    {
+      log_error(error_msg + stringprep_strerror(rc));
+      return "";
+    }
+  std::get<0>(cached)->second = std::string(local) + "@" + domain + "/" + resource;
+  return std::get<0>(cached)->second;
+
+#else
+  (void)original;
+  return "";
+#endif
+}