path: root/apt-pkg/deb/debmetaindex.cc

#include <config.h>

#include <apt-pkg/acquire-item.h>
#include <apt-pkg/aptconfiguration.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/debindexfile.h>
#include <apt-pkg/debmetaindex.h>
#include <apt-pkg/error.h>
#include <apt-pkg/fileutl.h>
#include <apt-pkg/gpgv.h>
#include <apt-pkg/hashes.h>
#include <apt-pkg/macros.h>
#include <apt-pkg/metaindex.h>
#include <apt-pkg/pkgcachegen.h>
#include <apt-pkg/sourcelist.h>
#include <apt-pkg/strutl.h>
#include <apt-pkg/tagfile.h>

#include <algorithm>
#include <cassert>
#include <map>
#include <optional>
#include <sstream>
#include <string>
#include <utility>
#include <vector>

#include <cstring>
#include <sys/stat.h>

#include <apti18n.h>

static std::string transformFingergrpints(std::string finger) /*{{{*/
{
   std::transform(finger.begin(), finger.end(), finger.begin(), ::toupper);
   if (finger.length() == 40)
   {
      if (finger.find_first_not_of("0123456789ABCDEF") == std::string::npos)
	 return finger;
   }
   else if (finger.length() == 41)
   {
      auto bang = finger.find_first_not_of("0123456789ABCDEF");
      if (bang == 40 && finger[bang] == '!')
	 return finger;
   }
   return "";
}
									/*}}}*/
static std::string transformFingergrpintsWithFilenames(std::string const &finger) /*{{{*/
{
   // no check for existence as we could be chrooting later or such things
   if (finger.empty() == false && finger[0] == '/')
      return finger;
   return transformFingergrpints(finger);
}
									/*}}}*/
// Introducer is set if additional keys may be introduced, for example	/*{{{*/
// by setting it to a filename or a complete key
static std::string NormalizeSignedBy(std::string SignedBy, bool const Introducer)
{
   // This is an embedded public pgp key, normalize spaces inside it and empty "." lines
   if (Introducer && SignedBy.find("-----BEGIN PGP PUBLIC KEY BLOCK-----") != std::string::npos) {
      std::istringstream is(SignedBy);
      std::ostringstream os;
      std::string line;

      while (std::getline(is, line)) {
	 line = APT::String::Strip(line);
	 // The special encoding for empty lines in deb822
	 if (line == ".")
	    line="";
	 os << line << std::endl;
      }
      return os.str();
   }

   // we could go all fancy and allow short/long/string matches as gpgv/apt-key does,
   // but fingerprints are harder to fake than the others and this option is set once,
   // not interactively all the time so easy to type is not really a concern.
   std::transform(SignedBy.begin(), SignedBy.end(), SignedBy.begin(), [](char const c) {
      return (isspace_ascii(c) == 0) ? c : ',';
   });
   auto fingers = VectorizeString(SignedBy, ',');
   auto const isAnEmptyString = [](std::string const &s) { return s.empty(); };
   fingers.erase(std::remove_if(fingers.begin(), fingers.end(), isAnEmptyString), fingers.end());
   if (unlikely(fingers.empty()))
      return "";
   if (Introducer)
      std::transform(fingers.begin(), fingers.end(), fingers.begin(), transformFingergrpintsWithFilenames);
   else
      std::transform(fingers.begin(), fingers.end(), fingers.begin(), transformFingergrpints);
   if (std::any_of(fingers.begin(), fingers.end(), isAnEmptyString))
      return "";
   std::stringstream os;
   std::copy(fingers.begin(), fingers.end() - 1, std::ostream_iterator<std::string>(os, ","));
   os << *fingers.rbegin();
   return os.str();
}
									/*}}}*/

class APT_HIDDEN debReleaseIndexPrivate					/*{{{*/
{
   public:
   struct APT_HIDDEN debSectionEntry
   {
      std::string const sourcesEntry;
      std::string const Name;
      std::vector<std::string> const Targets;
      std::vector<std::string> const Architectures;
      std::vector<std::string> const Languages;
      bool const UsePDiffs;
      std::string const UseByHash;
   };

   std::vector<debSectionEntry> DebEntries;
   std::vector<debSectionEntry> DebSrcEntries;

   metaIndex::TriState CheckValidUntil;
   time_t ValidUntilMin;
   time_t ValidUntilMax;

   metaIndex::TriState CheckDate;
   time_t DateMaxFuture;
   time_t NotBefore;

   std::string Snapshot;
   std::string SnapshotsServer;

   std::vector<std::string> Architectures;
   std::vector<std::string> NoSupportForAll;
   std::vector<std::string> SupportedComponents;
   std::map<std::string, std::string> const ReleaseOptions;

   explicit debReleaseIndexPrivate(std::map<std::string, std::string> const &Options) : CheckValidUntil(metaIndex::TRI_UNSET), ValidUntilMin(0), ValidUntilMax(0), CheckDate(metaIndex::TRI_UNSET), DateMaxFuture(0), NotBefore(0), ReleaseOptions(Options) {}
};
									/*}}}*/
// ReleaseIndex::MetaIndex* - display helpers				/*{{{*/
std::string debReleaseIndex::MetaIndexInfo(const char *Type) const
{
   std::string Info = ::URI::ArchiveOnly(URI) + ' ';
   if (Dist[Dist.size() - 1] == '/')
   {
      if (Dist != "/")
	 Info += Dist;
   }
   else
      Info += Dist;
   Info += " ";
   Info += Type;
   return Info;
}
std::string debReleaseIndex::Describe() const
{
   return MetaIndexInfo("Release");
}

std::string debReleaseIndex::MetaIndexFile(const char *Type) const
{
   return _config->FindDir("Dir::State::lists") +
      URItoFileName(MetaIndexURI(Type));
}
static std::string constructMetaIndexURI(std::string URI, std::string const &Dist, char const * const Type)
{
   if (Dist == "/")
      ;
   else if (Dist[Dist.size()-1] == '/')
      URI += pkgAcquire::URIEncode(Dist);
   else
      URI += "dists/" + pkgAcquire::URIEncode(Dist) + "/";
   return URI + pkgAcquire::URIEncode(Type);
}
std::string debReleaseIndex::MetaIndexURI(const char *Type) const
{
   return constructMetaIndexURI(URI, Dist, Type);
}
									/*}}}*/
// ReleaseIndex Con- and Destructors					/*{{{*/
debReleaseIndex::debReleaseIndex(std::string const &URI, std::string const &Dist, std::map<std::string, std::string> const &Options) :
					metaIndex(URI, Dist, "deb"), d(new debReleaseIndexPrivate(Options))
{}
debReleaseIndex::debReleaseIndex(std::string const &URI, std::string const &Dist, bool const pTrusted, std::map<std::string, std::string> const &Options) :
					metaIndex(URI, Dist, "deb"), d(new debReleaseIndexPrivate(Options))
{
   Trusted = pTrusted ? TRI_YES : TRI_NO;
}
debReleaseIndex::~debReleaseIndex() {
   if (d != NULL)
      delete d;
}
									/*}}}*/
// ReleaseIndex::GetIndexTargets					/*{{{*/
static void GetIndexTargetsFor(char const * const Type, std::string const &URI, std::string const &Dist,
      std::vector<debReleaseIndexPrivate::debSectionEntry> const &entries,
      std::vector<IndexTarget> &IndexTargets, std::map<std::string, std::string> const &ReleaseOptions)
{
   bool const flatArchive = (Dist[Dist.length() - 1] == '/');
   std::string const baseURI = constructMetaIndexURI(URI, Dist, "");

   std::string DefCompressionTypes;
   {
      std::vector<std::string> types = APT::Configuration::getCompressionTypes();
      if (types.empty() == false)
      {
	 std::ostringstream os;
	 std::copy(types.begin(), types.end()-1, std::ostream_iterator<std::string>(os, " "));
	 os << *types.rbegin();
	 DefCompressionTypes = os.str();
      }
   }
   std::string DefKeepCompressedAs;
   {
      std::vector<APT::Configuration::Compressor> comps = APT::Configuration::getCompressors();
      if (comps.empty() == false)
      {
	 std::sort(comps.begin(), comps.end(),
	       [](APT::Configuration::Compressor const &a, APT::Configuration::Compressor const &b) { return a.Cost < b.Cost; });
	 std::ostringstream os;
	 for (auto const &c : comps)
	    if (c.Cost != 0)
	       os << c.Extension.substr(1) << ' ';
	 DefKeepCompressedAs = os.str();
      }
      DefKeepCompressedAs += "uncompressed";
   }

   std::vector<std::string> const NativeArchs = { _config->Find("APT::Architecture"), "implicit:all" };
   bool const GzipIndex = _config->FindB("Acquire::GzipIndexes", false);
   for (std::vector<debReleaseIndexPrivate::debSectionEntry>::const_iterator E = entries.begin(); E != entries.end(); ++E)
   {
      for (std::vector<std::string>::const_iterator T = E->Targets.begin(); T != E->Targets.end(); ++T)
      {
#define APT_T_CONFIG_STR(X, Y) _config->Find(std::string("Acquire::IndexTargets::") + Type  + "::" + *T + "::" + (X), (Y))
#define APT_T_CONFIG_BOOL(X, Y) _config->FindB(std::string("Acquire::IndexTargets::") + Type  + "::" + *T + "::" + (X), (Y))
	 std::string const tplMetaKey = APT_T_CONFIG_STR(flatArchive ? "flatMetaKey" : "MetaKey", "");
	 std::string const tplShortDesc = APT_T_CONFIG_STR("ShortDescription", "");
	 std::string const tplLongDesc = "$(SITE) " + APT_T_CONFIG_STR(flatArchive ? "flatDescription" : "Description", "");
	 std::string const tplIdentifier = APT_T_CONFIG_STR("Identifier", *T);
	 bool const IsOptional = APT_T_CONFIG_BOOL("Optional", true);
	 bool const KeepCompressed = APT_T_CONFIG_BOOL("KeepCompressed", GzipIndex);
	 bool const DefaultEnabled = APT_T_CONFIG_BOOL("DefaultEnabled", true);
	 bool const UsePDiffs = APT_T_CONFIG_BOOL("PDiffs", E->UsePDiffs);
	 std::string const UseByHash = APT_T_CONFIG_STR("By-Hash", E->UseByHash);
	 std::string const CompressionTypes = APT_T_CONFIG_STR("CompressionTypes", DefCompressionTypes);
	 std::string KeepCompressedAs = APT_T_CONFIG_STR("KeepCompressedAs", "");
	 std::string const FallbackOf = APT_T_CONFIG_STR("Fallback-Of", "");
#undef APT_T_CONFIG_BOOL
#undef APT_T_CONFIG_STR
	 if (tplMetaKey.empty())
	    continue;

	 if (KeepCompressedAs.empty())
	    KeepCompressedAs = DefKeepCompressedAs;
	 else
	 {
	    std::vector<std::string> const defKeep = VectorizeString(DefKeepCompressedAs, ' ');
	    std::vector<std::string> const valKeep = VectorizeString(KeepCompressedAs, ' ');
	    std::vector<std::string> keep;
	    for (auto const &val : valKeep)
	    {
	       if (val.empty())
		  continue;
	       if (std::find(defKeep.begin(), defKeep.end(), val) == defKeep.end())
		  continue;
	       keep.push_back(val);
	    }
	    if (std::find(keep.begin(), keep.end(), "uncompressed") == keep.end())
	       keep.push_back("uncompressed");
	    std::ostringstream os;
	    std::copy(keep.begin(), keep.end()-1, std::ostream_iterator<std::string>(os, " "));
	    os << *keep.rbegin();
	    KeepCompressedAs = os.str();
	 }

	 for (std::vector<std::string>::const_iterator L = E->Languages.begin(); L != E->Languages.end(); ++L)
	 {
	    if (*L == "none" && tplMetaKey.find("$(LANGUAGE)") != std::string::npos)
	       continue;

	    for (std::vector<std::string>::const_iterator A = E->Architectures.begin(); A != E->Architectures.end(); ++A)
	    {
	       for (auto const &NativeArch: NativeArchs)
	       {
		  constexpr static auto BreakPoint = "$(NATIVE_ARCHITECTURE)";
		  // available in templates
		  std::map<std::string, std::string> Options;
		  Options.insert(ReleaseOptions.begin(), ReleaseOptions.end());
		  if (tplMetaKey.find("$(COMPONENT)") != std::string::npos)
		     Options.emplace("COMPONENT", E->Name);
		  if (tplMetaKey.find("$(LANGUAGE)") != std::string::npos)
		     Options.emplace("LANGUAGE", *L);
		  if (tplMetaKey.find("$(ARCHITECTURE)") != std::string::npos)
		     Options.emplace("ARCHITECTURE", (*A == "implicit:all") ? "all" : *A);
		  else if (tplMetaKey.find("$(NATIVE_ARCHITECTURE)") != std::string::npos)
		     Options.emplace("ARCHITECTURE", (NativeArch == "implicit:all") ? "all" : NativeArch);
		  if (tplMetaKey.find("$(NATIVE_ARCHITECTURE)") != std::string::npos)
		     Options.emplace("NATIVE_ARCHITECTURE", (NativeArch == "implicit:all") ? "all" : NativeArch);

		  std::string MetaKey = tplMetaKey;
		  std::string ShortDesc = tplShortDesc;
		  std::string LongDesc = tplLongDesc;
		  std::string Identifier = tplIdentifier;
		  for (std::map<std::string, std::string>::const_iterator O = Options.begin(); O != Options.end(); ++O)
		  {
		     std::string const varname = "$(" + O->first + ")";
		     MetaKey = SubstVar(MetaKey, varname, O->second);
		     ShortDesc = SubstVar(ShortDesc, varname, O->second);
		     LongDesc = SubstVar(LongDesc, varname, O->second);
		     Identifier = SubstVar(Identifier, varname, O->second);
		  }

		  {
		     auto const dup = std::find_if(IndexTargets.begin(), IndexTargets.end(), [&](IndexTarget const &IT) {
			return MetaKey == IT.MetaKey && baseURI == IT.Option(IndexTarget::BASE_URI) &&
			   E->sourcesEntry == IT.Option(IndexTarget::SOURCESENTRY) && *T == IT.Option(IndexTarget::CREATED_BY);
		     });
		     if (dup != IndexTargets.end())
		     {
			if (tplMetaKey.find(BreakPoint) == std::string::npos)
			   break;
			continue;
		     }
		  }

		  {
		     auto const dup = std::find_if(IndexTargets.begin(), IndexTargets.end(), [&](IndexTarget const &IT) {
			return MetaKey == IT.MetaKey && baseURI == IT.Option(IndexTarget::BASE_URI) &&
			   E->sourcesEntry == IT.Option(IndexTarget::SOURCESENTRY) && *T != IT.Option(IndexTarget::CREATED_BY);
			});
		     if (dup != IndexTargets.end())
		     {
			std::string const dupT = dup->Option(IndexTarget::CREATED_BY);
			std::string const dupEntry = dup->Option(IndexTarget::SOURCESENTRY);
			//TRANSLATOR: an identifier like Packages; Releasefile key indicating
			// a file like main/binary-amd64/Packages; another identifier like Contents;
			// filename and linenumber of the sources.list entry currently parsed
			_error->Warning(_("Target %s wants to acquire the same file (%s) as %s from source %s"),
			      T->c_str(), MetaKey.c_str(), dupT.c_str(), dupEntry.c_str());
			if (tplMetaKey.find(BreakPoint) == std::string::npos)
			   break;
			continue;
		     }
		  }

		  {
		     auto const dup = std::find_if(IndexTargets.begin(), IndexTargets.end(), [&](IndexTarget const &T) {
			return MetaKey == T.MetaKey && baseURI == T.Option(IndexTarget::BASE_URI) &&
			   E->sourcesEntry != T.Option(IndexTarget::SOURCESENTRY);
		     });
		     if (dup != IndexTargets.end())
		     {
			std::string const dupEntry = dup->Option(IndexTarget::SOURCESENTRY);
			if (T->find("legacy") == std::string::npos)
			{
			   //TRANSLATOR: an identifier like Packages; Releasefile key indicating
			   // a file like main/binary-amd64/Packages; filename and linenumber of
			   // two sources.list entries
			   _error->Warning(_("Target %s (%s) is configured multiple times in %s and %s"),
					   T->c_str(), MetaKey.c_str(), dupEntry.c_str(), E->sourcesEntry.c_str());
			}
			if (tplMetaKey.find(BreakPoint) == std::string::npos)
			   break;
			continue;
		     }
		  }

		  // not available in templates, but in the indextarget
		  Options.insert(std::make_pair("IDENTIFIER", Identifier));
		  Options.insert(std::make_pair("TARGET_OF", Type));
		  Options.insert(std::make_pair("CREATED_BY", *T));
		  Options.insert(std::make_pair("FALLBACK_OF", FallbackOf));
		  Options.insert(std::make_pair("PDIFFS", UsePDiffs ? "yes" : "no"));
		  Options.insert(std::make_pair("BY_HASH", UseByHash));
		  Options.insert(std::make_pair("DEFAULTENABLED", DefaultEnabled ? "yes" : "no"));
		  Options.insert(std::make_pair("COMPRESSIONTYPES", CompressionTypes));
		  Options.insert(std::make_pair("KEEPCOMPRESSEDAS", KeepCompressedAs));
		  Options.insert(std::make_pair("SOURCESENTRY", E->sourcesEntry));

		  bool IsOpt = IsOptional;
		  {
		     auto const arch = Options.find("ARCHITECTURE");
		     if (arch != Options.end() && arch->second == "all")
		     {
			// one of them must be implicit:all then
			if (*A != "all" && NativeArch != "all")
			   IsOpt = true;
			else // user used arch=all explicitly
			   Options.emplace("Force-Support-For-All", "yes");
		     }
		  }

		  IndexTarget Target(
			MetaKey,
			ShortDesc,
			LongDesc,
			baseURI + MetaKey,
			IsOpt,
			KeepCompressed,
			Options
			);
		  IndexTargets.push_back(Target);

		  if (tplMetaKey.find(BreakPoint) == std::string::npos)
		     break;
	       }

	       if (tplMetaKey.find("$(ARCHITECTURE)") == std::string::npos)
		  break;

	    }

	    if (tplMetaKey.find("$(LANGUAGE)") == std::string::npos)
	       break;

	 }

      }
   }
}
std::vector<IndexTarget> debReleaseIndex::GetIndexTargets() const
{
   std::vector<IndexTarget> IndexTargets;
   GetIndexTargetsFor("deb-src", URI, Dist, d->DebSrcEntries, IndexTargets, d->ReleaseOptions);
   GetIndexTargetsFor("deb", URI, Dist, d->DebEntries, IndexTargets, d->ReleaseOptions);
   return IndexTargets;
}
									/*}}}*/
void debReleaseIndex::AddComponent(std::string const &sourcesEntry,	/*{{{*/
	 bool const isSrc, std::string const &Name,
	 std::vector<std::string> const &Targets,
	 std::vector<std::string> const &Architectures,
	 std::vector<std::string> Languages,
	 bool const usePDiffs, std::string const &useByHash)
{
   if (Languages.empty() == true)
      Languages.push_back("none");
   debReleaseIndexPrivate::debSectionEntry const entry = {
      sourcesEntry, Name, Targets, Architectures, Languages, usePDiffs, useByHash
   };
   if (isSrc)
      d->DebSrcEntries.push_back(entry);
   else
      d->DebEntries.push_back(entry);
}
									/*}}}*/
std::string debReleaseIndex::ArchiveURI(std::string const &File) const	/*{{{*/
{
   if (File.empty())
      return URI;
   return URI + pkgAcquire::URIEncode(File);
}
									/*}}}*/

bool debReleaseIndex::Load(std::string const &Filename, std::string * const ErrorText)/*{{{*/
{
   LoadedSuccessfully = TRI_NO;
   FileFd Fd;
   if (OpenMaybeClearSignedFile(Filename, Fd) == false)
      return false;

   pkgTagFile TagFile(&Fd, Fd.Size());
   if (Fd.IsOpen() == false || Fd.Failed())
   {
      if (ErrorText != NULL)
	 strprintf(*ErrorText, _("Unable to parse Release file %s"),Filename.c_str());
      return false;
   }

   pkgTagSection Section;
   const char *Start, *End;
   if (TagFile.Step(Section) == false)
   {
      if (ErrorText != NULL)
	 strprintf(*ErrorText, _("No sections in Release file %s"), Filename.c_str());
      return false;
   }
   // FIXME: find better tag name
   SupportsAcquireByHash = Section.FindB("Acquire-By-Hash", false);

   Origin = Section.FindS("Origin");
   Label = Section.FindS("Label");
   Version = Section.FindS("Version");
   Suite = Section.FindS("Suite");
   Codename = Section.FindS("Codename");
   ReleaseNotes = Section.FindS("Release-Notes");
   d->SnapshotsServer = Section.FindS("Snapshots");
   {
      std::string const archs = Section.FindS("Architectures");
      if (archs.empty() == false)
	 d->Architectures = VectorizeString(archs, ' ');
   }
   {
      std::string const targets = Section.FindS("No-Support-for-Architecture-all");
      if (targets.empty() == false)
	 d->NoSupportForAll = VectorizeString(targets, ' ');
   }
   for (auto const &comp: VectorizeString(Section.FindS("Components"), ' '))
   {
      if (comp.empty())
	 continue;
      auto const pos = comp.find_last_of('/');
      if (pos != std::string::npos) // e.g. security.debian.org uses this style
	 d->SupportedComponents.push_back(comp.substr(pos + 1));
      d->SupportedComponents.push_back(std::move(comp));
   }
   {
      decltype(pkgCache::ReleaseFile::Flags) flags = 0;
      Section.FindFlag("NotAutomatic", flags, pkgCache::Flag::NotAutomatic);
      signed short defaultpin = 500;
      if ((flags & pkgCache::Flag::NotAutomatic) == pkgCache::Flag::NotAutomatic)
      {
	 Section.FindFlag("ButAutomaticUpgrades", flags, pkgCache::Flag::ButAutomaticUpgrades);
	 if ((flags & pkgCache::Flag::ButAutomaticUpgrades) == pkgCache::Flag::ButAutomaticUpgrades)
	    defaultpin = 100;
	 else
	    defaultpin = 1;
      }
      DefaultPin = defaultpin;
   }

   bool FoundHashSum = false;
   bool FoundStrongHashSum = false;
   for (auto const hashinfo : HashString::SupportedHashesInfo())
   {
      if (not Section.Find(hashinfo.namekey, Start, End))
	 continue;

      std::string Name;
      std::string Hash;
      unsigned long long Size;
      while (Start < End)
      {
	 if (!parseSumData(Start, End, Name, Hash, Size))
	    return false;

	 HashString const hs(hashinfo.name.to_string(), Hash);
         if (Entries.find(Name) == Entries.end())
         {
            metaIndex::checkSum *Sum = new metaIndex::checkSum;
            Sum->MetaKeyFilename = Name;
            Sum->Size = Size;
	    Sum->Hashes.FileSize(Size);
	    Entries[Name] = Sum;
         }
         Entries[Name]->Hashes.push_back(hs);
         FoundHashSum = true;
	 if (FoundStrongHashSum == false && hs.usable() == true)
	    FoundStrongHashSum = true;
      }
   }

   bool AuthPossible = false;
   if(FoundHashSum == false)
      _error->Warning(_("No Hash entry in Release file %s"), Filename.c_str());
   else if(FoundStrongHashSum == false)
      _error->Warning(_("No Hash entry in Release file %s which is considered strong enough for security purposes"), Filename.c_str());
   else
      AuthPossible = true;

   std::string const StrDate = Section.FindS("Date");
   if (RFC1123StrToTime(StrDate, Date) == false)
   {
      _error->Warning( _("Invalid '%s' entry in Release file %s"), "Date", Filename.c_str());
      Date = 0;
   }

   bool CheckDate = _config->FindB("Acquire::Check-Date", true);
   if (d->CheckDate == metaIndex::TRI_NO)
      CheckDate = false;
   else if (d->CheckDate == metaIndex::TRI_YES)
      CheckDate = true;

   if (CheckDate)
   {
      auto const Label = GetLabel();
      // get the user settings for this archive
      time_t MaxFuture = d->DateMaxFuture;
      if (MaxFuture == 0)
      {
	 MaxFuture = _config->FindI("Acquire::Max-FutureTime", 10);
	 if (Label.empty() == false)
	    MaxFuture = _config->FindI(("Acquire::Max-FutureTime::" + Label).c_str(), MaxFuture);
      }

      d->NotBefore = Date - MaxFuture;

      bool CheckValidUntil = _config->FindB("Acquire::Check-Valid-Until", true);
      if (d->CheckValidUntil == metaIndex::TRI_NO)
	 CheckValidUntil = false;
      else if (d->CheckValidUntil == metaIndex::TRI_YES)
	 CheckValidUntil = true;

      if (CheckValidUntil == true)
      {
	 std::string const StrValidUntil = Section.FindS("Valid-Until");

	 // if we have a Valid-Until header in the Release file, use it as default
	 if (StrValidUntil.empty() == false)
	 {
	    if (RFC1123StrToTime(StrValidUntil, ValidUntil) == false)
	    {
	       if (ErrorText != NULL)
		  strprintf(*ErrorText, _("Invalid '%s' entry in Release file %s"), "Valid-Until", Filename.c_str());
	       return false;
	    }
	 }
	 auto const Label = GetLabel();
	 // get the user settings for this archive and use what expires earlier
	 time_t MaxAge = d->ValidUntilMax;
	 if (MaxAge == 0)
	 {
	    MaxAge = _config->FindI("Acquire::Max-ValidTime", 0);
	    if (Label.empty() == false)
	       MaxAge = _config->FindI(("Acquire::Max-ValidTime::" + Label).c_str(), MaxAge);
	 }
	 time_t MinAge = d->ValidUntilMin;
	 if (MinAge == 0)
	 {
	    MinAge = _config->FindI("Acquire::Min-ValidTime", 0);
	    if (Label.empty() == false)
	       MinAge = _config->FindI(("Acquire::Min-ValidTime::" + Label).c_str(), MinAge);
	 }

	 if (MinAge != 0 || ValidUntil != 0 || MaxAge != 0)
	 {
	    if (MinAge != 0 && ValidUntil != 0)
	    {
	       time_t const min_date = Date + MinAge;
	       if (ValidUntil < min_date)
		  ValidUntil = min_date;
	    }
	    if (MaxAge != 0 && Date != 0)
	    {
	       time_t const max_date = Date + MaxAge;
	       if (ValidUntil == 0 || ValidUntil > max_date)
		  ValidUntil = max_date;
	    }
	 }
      }
   }

   /* as the Release file is parsed only after it was verified, the Signed-By field
      does not effect the current, but the "next" Release file */
   auto Sign = Section.FindS("Signed-By");
   if (Sign.empty() == false)
   {
      SignedBy = NormalizeSignedBy(Sign, false);
      if (SignedBy.empty() && ErrorText != NULL)
	 strprintf(*ErrorText, _("Invalid '%s' entry in Release file %s"), "Signed-By", Filename.c_str());
   }

   if (AuthPossible)
      LoadedSuccessfully = TRI_YES;
   return AuthPossible;
}
									/*}}}*/
time_t debReleaseIndex::GetNotBefore() const /*{{{*/
{
   return d->NotBefore;
}
									/*}}}*/
metaIndex * debReleaseIndex::UnloadedClone() const			/*{{{*/
{
   if (Trusted == TRI_NO)
      return new debReleaseIndex(URI, Dist, false, d->ReleaseOptions);
   else if (Trusted == TRI_YES)
      return new debReleaseIndex(URI, Dist, true, d->ReleaseOptions);
   else
      return new debReleaseIndex(URI, Dist, d->ReleaseOptions);
}
									/*}}}*/
bool debReleaseIndex::parseSumData(const char *&Start, const char *End,	/*{{{*/
				   std::string &Name, std::string &Hash, unsigned long long &Size)
{
   Name = "";
   Hash = "";
   Size = 0;
   /* Skip over the first blank */
   while ((*Start == '\t' || *Start == ' ' || *Start == '\n' || *Start == '\r')
	  && Start < End)
      Start++;
   if (Start >= End)
      return false;

   /* Move EntryEnd to the end of the first entry (the hash) */
   const char *EntryEnd = Start;
   while ((*EntryEnd != '\t' && *EntryEnd != ' ')
	  && EntryEnd < End)
      EntryEnd++;
   if (EntryEnd == End)
      return false;

   Hash.append(Start, EntryEnd-Start);

   /* Skip over intermediate blanks */
   Start = EntryEnd;
   while (*Start == '\t' || *Start == ' ')
      Start++;
   if (Start >= End)
      return false;
   
   EntryEnd = Start;
   /* Find the end of the second entry (the size) */
   while ((*EntryEnd != '\t' && *EntryEnd != ' ' )
	  && EntryEnd < End)
      EntryEnd++;
   if (EntryEnd == End)
      return false;
   
   Size = strtoull (Start, NULL, 10);
      
   /* Skip over intermediate blanks */
   Start = EntryEnd;
   while (*Start == '\t' || *Start == ' ')
      Start++;
   if (Start >= End)
      return false;
   
   EntryEnd = Start;
   /* Find the end of the third entry (the filename) */
   while ((*EntryEnd != '\t' && *EntryEnd != ' ' && 
           *EntryEnd != '\n' && *EntryEnd != '\r')
	  && EntryEnd < End)
      EntryEnd++;

   Name.append(Start, EntryEnd-Start);
   Start = EntryEnd; //prepare for the next round
   return true;
}
									/*}}}*/

bool debReleaseIndex::GetIndexes(pkgAcquire *Owner, bool const &GetAll)/*{{{*/
{
#define APT_TARGET(X) IndexTarget("", X, MetaIndexInfo(X), MetaIndexURI(X), false, false, d->ReleaseOptions)
   pkgAcqMetaClearSig * const TransactionManager = new pkgAcqMetaClearSig(Owner,
	 APT_TARGET("InRelease"), APT_TARGET("Release"), APT_TARGET("Release.gpg"), this);
#undef APT_TARGET
   // special case for --print-uris
   if (GetAll)
      for (auto const &Target: GetIndexTargets())
	 if (Target.Option(IndexTarget::FALLBACK_OF).empty())
	    new pkgAcqIndex(Owner, TransactionManager, Target);

   return true;
}
									/*}}}*/
// ReleaseIndex::Set* TriState options					/*{{{*/
bool debReleaseIndex::SetTrusted(TriState const pTrusted)
{
   if (Trusted == TRI_UNSET)
      Trusted = pTrusted;
   else if (Trusted != pTrusted)
      // TRANSLATOR: The first is an option name from sources.list manpage, the other two URI and Suite
      return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), "Trusted", URI.c_str(), Dist.c_str());
   return true;
}
bool debReleaseIndex::SetCheckValidUntil(TriState const pCheckValidUntil)
{
   if (d->CheckValidUntil == TRI_UNSET)
      d->CheckValidUntil = pCheckValidUntil;
   else if (d->CheckValidUntil != pCheckValidUntil)
      return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), "Check-Valid-Until", URI.c_str(), Dist.c_str());
   return true;
}
bool debReleaseIndex::SetValidUntilMin(time_t const Valid)
{
   if (d->ValidUntilMin == 0)
      d->ValidUntilMin = Valid;
   else if (d->ValidUntilMin != Valid)
      return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), "Min-ValidTime", URI.c_str(), Dist.c_str());
   return true;
}
bool debReleaseIndex::SetValidUntilMax(time_t const Valid)
{
   if (d->ValidUntilMax == 0)
      d->ValidUntilMax = Valid;
   else if (d->ValidUntilMax != Valid)
      return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), "Max-ValidTime", URI.c_str(), Dist.c_str());
   return true;
}
bool debReleaseIndex::SetCheckDate(TriState const pCheckDate)
{
   if (d->CheckDate == TRI_UNSET)
      d->CheckDate = pCheckDate;
   else if (d->CheckDate != pCheckDate)
      return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), "Check-Date", URI.c_str(), Dist.c_str());
   return true;
}
bool debReleaseIndex::SetDateMaxFuture(time_t const DateMaxFuture)
{
   if (d->DateMaxFuture == 0)
      d->DateMaxFuture = DateMaxFuture;
   else if (d->DateMaxFuture != DateMaxFuture)
      return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), "Date-Max-Future", URI.c_str(), Dist.c_str());
   return true;
}
bool debReleaseIndex::SetSnapshot(std::string const Snapshot)
{
   if (d->Snapshot.empty())
      d->Snapshot = Snapshot;
   else if (d->Snapshot != Snapshot)
      return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), "Snapshot", URI.c_str(), Dist.c_str());
   return true;
}
std::string debReleaseIndex::GetSnapshotsServer() const
{
   return d->SnapshotsServer;
}
bool debReleaseIndex::SetSignedBy(std::string const &pSignedBy)
{
   if (SignedBy.empty() == true && pSignedBy.empty() == false)
   {
      SignedBy = NormalizeSignedBy(pSignedBy, true);
      if (SignedBy.empty())
	 _error->Error(_("Invalid value set for option %s regarding source %s %s (%s)"), "Signed-By", URI.c_str(), Dist.c_str(), "not a fingerprint");
   }
   else
   {
      auto const normalSignedBy = NormalizeSignedBy(pSignedBy, true);
      if (normalSignedBy.empty() == true)
         return true;
      if (normalSignedBy != SignedBy)
	 return _error->Error(_("Conflicting values set for option %s regarding source %s %s: %s != %s"), "Signed-By", URI.c_str(), Dist.c_str(), SignedBy.c_str(), normalSignedBy.c_str());
   }
   return true;
}
									/*}}}*/
// ReleaseIndex::IsTrusted						/*{{{*/
bool debReleaseIndex::IsTrusted() const
{
   if (Trusted == TRI_YES)
      return true;
   else if (Trusted == TRI_NO)
      return false;


   if(_config->FindB("APT::Authentication::TrustCDROM", false))
      if(URI.substr(0,strlen("cdrom:")) == "cdrom:")
	 return true;

   if (FileExists(MetaIndexFile("Release.gpg")))
      return true;

   return FileExists(MetaIndexFile("InRelease"));
}
									/*}}}*/
bool debReleaseIndex::IsArchitectureSupported(std::string const &arch) const/*{{{*/
{
   if (d->Architectures.empty())
      return true;
   return std::find(d->Architectures.begin(), d->Architectures.end(), arch) != d->Architectures.end();
}
									/*}}}*/
bool debReleaseIndex::IsArchitectureAllSupportedFor(IndexTarget const &target) const/*{{{*/
{
   if (target.Options.find("Force-Support-For-All") != target.Options.end())
      return true;
   if (IsArchitectureSupported("all") == false)
      return false;
   if (d->NoSupportForAll.empty())
      return true;
   return std::find(d->NoSupportForAll.begin(), d->NoSupportForAll.end(), target.Option(IndexTarget::CREATED_BY)) == d->NoSupportForAll.end();
}
									/*}}}*/
bool debReleaseIndex::HasSupportForComponent(std::string const &component) const/*{{{*/
{
   if (d->SupportedComponents.empty())
      return true;
   return std::find(d->SupportedComponents.begin(), d->SupportedComponents.end(), component) != d->SupportedComponents.end();
}
									/*}}}*/
std::vector <pkgIndexFile *> *debReleaseIndex::GetIndexFiles()		/*{{{*/
{
   if (Indexes != NULL)
      return Indexes;

   Indexes = new std::vector<pkgIndexFile*>();
   bool const istrusted = IsTrusted();
   for (auto const &T: GetIndexTargets())
   {
      std::string const TargetName = T.Option(IndexTarget::CREATED_BY);
      if (TargetName == "Packages")
	 Indexes->push_back(new debPackagesIndex(T, istrusted));
      else if (TargetName == "Sources")
	 Indexes->push_back(new debSourcesIndex(T, istrusted));
      else if (TargetName == "Translations")
	 Indexes->push_back(new debTranslationsIndex(T));
   }
   return Indexes;
}
									/*}}}*/
std::map<std::string, std::string> debReleaseIndex::GetReleaseOptions()
{
   return d->ReleaseOptions;
}

static bool ReleaseFileName(debReleaseIndex const * const That, std::string &ReleaseFile)/*{{{*/
{
   ReleaseFile = That->MetaIndexFile("InRelease");
   bool releaseExists = false;
   if (FileExists(ReleaseFile) == true)
      releaseExists = true;
   else
   {
      ReleaseFile = That->MetaIndexFile("Release");
      if (FileExists(ReleaseFile))
	 releaseExists = true;
   }
   return releaseExists;
}
									/*}}}*/
bool debReleaseIndex::Merge(pkgCacheGenerator &Gen,OpProgress * /*Prog*/) const/*{{{*/
{
   std::string ReleaseFile;
   bool const releaseExists = ReleaseFileName(this, ReleaseFile);

   ::URI Tmp(URI);
   if (Gen.SelectReleaseFile(ReleaseFile, Tmp.Host) == false)
      return _error->Error("Problem with SelectReleaseFile %s", ReleaseFile.c_str());

   if (releaseExists == false)
      return true;

   FileFd Rel;
   // Beware: The 'Release' file might be clearsigned in case the
   // signature for an 'InRelease' file couldn't be checked
   if (OpenMaybeClearSignedFile(ReleaseFile, Rel) == false)
      return false;

   // Store the IMS information
   pkgCache::RlsFileIterator File = Gen.GetCurRlsFile();
   pkgCacheGenerator::Dynamic<pkgCache::RlsFileIterator> DynFile(File);
   // Rel can't be used as this is potentially a temporary file
   struct stat Buf;
   if (stat(ReleaseFile.c_str(), &Buf) != 0)
      return _error->Errno("fstat", "Unable to stat file %s", ReleaseFile.c_str());
   File->Size = Buf.st_size;
   File->mtime = Buf.st_mtime;

   pkgTagFile TagFile(&Rel, Rel.Size());
   pkgTagSection Section;
   if (Rel.IsOpen() == false || Rel.Failed() || TagFile.Step(Section) == false)
      return false;

   std::string data;
   #define APT_INRELEASE(TYPE, TAG, STORE) \
   data = Section.FindS(TAG); \
   if (data.empty() == false) \
   { \
      map_stringitem_t const storage = Gen.StoreString(pkgCacheGenerator::TYPE, data); \
      if (storage == 0) return false; \
      STORE = storage; \
   }
   APT_INRELEASE(MIXED, "Suite", File->Archive)
   APT_INRELEASE(VERSIONNUMBER, "Version", File->Version)
   APT_INRELEASE(MIXED, "Origin", File->Origin)
   APT_INRELEASE(MIXED, "Codename", File->Codename)
   APT_INRELEASE(MIXED, "Label", File->Label)
   #undef APT_INRELEASE
   Section.FindFlag("NotAutomatic", File->Flags, pkgCache::Flag::NotAutomatic);
   Section.FindFlag("ButAutomaticUpgrades", File->Flags, pkgCache::Flag::ButAutomaticUpgrades);

   return true;
}
									/*}}}*/
// ReleaseIndex::FindInCache - Find this index				/*{{{*/
pkgCache::RlsFileIterator debReleaseIndex::FindInCache(pkgCache &Cache, bool const ModifyCheck) const
{
   std::string ReleaseFile;
   bool const releaseExists = ReleaseFileName(this, ReleaseFile);

   pkgCache::RlsFileIterator File = Cache.RlsFileBegin();
   for (; File.end() == false; ++File)
   {
       if (File->FileName == 0 || ReleaseFile != File.FileName())
	 continue;

       // empty means the file does not exist by "design"
       if (ModifyCheck == false || (releaseExists == false && File->Size == 0))
	  return File;

      struct stat St;
      if (stat(File.FileName(),&St) != 0)
      {
         if (_config->FindB("Debug::pkgCacheGen", false))
	    std::clog << "ReleaseIndex::FindInCache - stat failed on " << File.FileName() << std::endl;
	 return pkgCache::RlsFileIterator(Cache);
      }
      if ((unsigned)St.st_size != File->Size || St.st_mtime != File->mtime)
      {
         if (_config->FindB("Debug::pkgCacheGen", false))
	    std::clog << "ReleaseIndex::FindInCache - size (" << St.st_size << " <> " << File->Size
			<< ") or mtime (" << St.st_mtime << " <> " << File->mtime
			<< ") doesn't match for " << File.FileName() << std::endl;
	 return pkgCache::RlsFileIterator(Cache);
      }
      return File;
   }

   return File;
}
									/*}}}*/

class APT_HIDDEN debSLTypeDebian : public pkgSourceList::Type		/*{{{*/
{
   static std::optional<std::vector<std::string>> getDefaultSetOf(std::string const &Name,
	 std::map<std::string, std::string> const &Options)
   {
      auto const val = Options.find(Name);
      if (val != Options.end())
	 return VectorizeString(val->second, ',');
      return {};
   }
   static std::vector<std::string> applyPlusMinusOptions(std::string const &Name,
	 std::map<std::string, std::string> const &Options, std::vector<std::string> &&Values)
   {
      auto val = Options.find(Name + "+");
      if (val != Options.end())
      {
	 std::vector<std::string> const plus = VectorizeString(val->second, ',');
	 std::copy_if(plus.begin(), plus.end(), std::back_inserter(Values), [&Values](std::string const &v) {
	       return std::find(Values.begin(), Values.end(), v) == Values.end();
	       });
      }
      if ((val = Options.find(Name + "-")) != Options.end())
      {
	 std::vector<std::string> const minus = VectorizeString(val->second, ',');
	 Values.erase(std::remove_if(Values.begin(), Values.end(), [&minus](std::string const &v) {
		  return std::find(minus.begin(), minus.end(), v) != minus.end();
		  }), Values.end());
      }
      return std::move(Values);
   }
   static std::vector<std::string> parsePlusMinusOptions(std::string const &Name,
	 std::map<std::string, std::string> const &Options, std::vector<std::string> const &defaultValues)
   {
      return applyPlusMinusOptions(Name, Options, getDefaultSetOf(Name, Options).value_or(defaultValues));
   }
   static std::vector<std::string> parsePlusMinusArchOptions(std::string const &Name,
	 std::map<std::string, std::string> const &Options)
   {
      std::vector<std::string> Values;
     if (auto opt = getDefaultSetOf(Name, Options); opt.has_value())
        Values = opt.value();
     else
     {
	Values = APT::Configuration::getArchitectures();
	auto veryforeign = _config->FindVector("APT::BarbarianArchitectures");
	Values.reserve(Values.size() + veryforeign.size());
	std::move(veryforeign.begin(), veryforeign.end(), std::back_inserter(Values));
     }
      // all is a very special architecture users shouldn't be concerned with explicitly
      // but if the user does, do not override the choice
      auto const val = Options.find(Name + "-");
      if (val != Options.end())
      {
	 std::vector<std::string> const minus = VectorizeString(val->second, ',');
	 if (std::find(minus.begin(), minus.end(), "all") != minus.end())
	    return applyPlusMinusOptions(Name, Options, std::move(Values));
      }
      Values = applyPlusMinusOptions(Name, Options, std::move(Values));
      if (std::find(Values.begin(), Values.end(), "all") == Values.end())
	 Values.push_back("implicit:all");
      return Values;
   }
   static std::vector<std::string> parsePlusMinusTargetOptions(char const * const Name,
	 std::map<std::string, std::string> const &Options)
   {
      std::vector<std::string> const alltargets = _config->FindVector(std::string("Acquire::IndexTargets::") + Name, "", true);
      std::vector<std::string> deftargets;
      deftargets.reserve(alltargets.size());
      std::copy_if(alltargets.begin(), alltargets.end(), std::back_inserter(deftargets), [&](std::string const &t) {
	 std::string c = "Acquire::IndexTargets::";
	 c.append(Name).append("::").append(t).append("::DefaultEnabled");
	 return _config->FindB(c, true);
      });
      std::vector<std::string> mytargets = parsePlusMinusOptions("target", Options, deftargets);
      for (auto const &target : alltargets)
      {
	 std::map<std::string, std::string>::const_iterator const opt = Options.find(target);
	 if (opt == Options.end())
	    continue;
	 auto const idMatch = [&](std::string const &t) {
	    return target == _config->Find(std::string("Acquire::IndexTargets::") + Name + "::" + t + "::Identifier", t);
	 };
	 if (StringToBool(opt->second))
	    std::copy_if(alltargets.begin(), alltargets.end(), std::back_inserter(mytargets), idMatch);
	 else
	    mytargets.erase(std::remove_if(mytargets.begin(), mytargets.end(), idMatch), mytargets.end());
      }
      // if we can't order it in a 1000 steps we give up… probably a cycle
      for (auto i = 0; i < 1000; ++i)
      {
	 bool Changed = false;
	 for (auto t = mytargets.begin(); t != mytargets.end(); ++t)
	 {
	    std::string const fallback = _config->Find(std::string("Acquire::IndexTargets::") + Name + "::" + *t + "::Fallback-Of");
	    if (fallback.empty())
	       continue;
	    auto const faller = std::find(mytargets.begin(), mytargets.end(), fallback);
	    if (faller == mytargets.end() || faller < t)
	       continue;
	    Changed = true;
	    auto const tv = *t;
	    mytargets.erase(t);
	    mytargets.emplace_back(tv);
	    break;
	 }
	 if (Changed == false)
	    break;
      }
      // remove duplicates without changing the order (in first appearance)
      {
	 std::set<std::string> seenOnce;
	 mytargets.erase(std::remove_if(mytargets.begin(), mytargets.end(), [&](std::string const &t) {
	    return seenOnce.insert(t).second == false;
	 }), mytargets.end());
      }
      return mytargets;
   }

   metaIndex::TriState GetTriStateOption(std::map<std::string, std::string>const &Options, char const * const name) const
   {
      std::map<std::string, std::string>::const_iterator const opt = Options.find(name);
      if (opt != Options.end())
	 return StringToBool(opt->second, false) ? metaIndex::TRI_YES : metaIndex::TRI_NO;
      return metaIndex::TRI_DONTCARE;
   }

   static time_t GetTimeOption(std::map<std::string, std::string>const &Options, char const * const name)
   {
      std::map<std::string, std::string>::const_iterator const opt = Options.find(name);
      if (opt == Options.end())
	 return 0;
      return strtoull(opt->second.c_str(), NULL, 10);
   }

   static bool GetBoolOption(std::map<std::string, std::string> const &Options, char const * const name, bool const defVal)
   {
      std::map<std::string, std::string>::const_iterator const opt = Options.find(name);
      if (opt == Options.end())
	 return defVal;
      return StringToBool(opt->second, defVal);
   }
   static std::string GetSnapshotOption(std::map<std::string, std::string> const &Options, char const * const name, const std::string defVal="")
   {
      std::map<std::string, std::string>::const_iterator const opt = Options.find(name);
      if (opt == Options.end())
	 return defVal;
      int boolVal = StringToBool(opt->second, -1);
      if (boolVal != -1)
	 return boolVal ? _config->Find("APT::Snapshot") : "";
      return opt->second;
   }


   static std::vector<std::string> GetMapKeys(std::map<std::string, std::string> const &Options)
   {
      std::vector<std::string> ret;
      ret.reserve(Options.size());
      std::transform(Options.begin(), Options.end(), std::back_inserter(ret),
		     [](auto &&O) { return O.first; });
      std::sort(ret.begin(), ret.end());
      auto r = std::remove(ret.begin(), ret.end(), "SHADOWED");
      ret.erase(r, ret.end());
      return ret;
   }

   static bool MapsAreEqual(std::map<std::string, std::string> const &OptionsA,
	 std::map<std::string, std::string> const &OptionsB,
	 std::string const &URI, std::string const &Dist)
   {
      auto const KeysA = GetMapKeys(OptionsA);
      auto const KeysB = GetMapKeys(OptionsB);
      auto const m = std::mismatch(KeysA.begin(), KeysA.end(), KeysB.begin());
      if (m.first != KeysA.end())
      {
	 if (std::find(KeysB.begin(), KeysB.end(), *m.first) == KeysB.end())
	    return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), m.first->c_str(), "<set>", "<unset>");
	 else
	    return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), m.second->c_str(), "<set>", "<unset>");
      }
      if (m.second != KeysB.end())
      {
	 if (std::find(KeysA.begin(), KeysA.end(), *m.second) == KeysA.end())
	    return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), m.first->c_str(), "<set>", "<unset>");
	 else
	    return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), m.second->c_str(), "<set>", "<unset>");
      }
      for (auto&& key: KeysA)
      {
	 if (key == "BASE_URI" || key == "REPO_URI" || key == "SITE" || key == "RELEASE")
	    continue;
	 auto const a = OptionsA.find(key);
	 auto const b = OptionsB.find(key);
	 if (unlikely(a == OptionsA.end() || b == OptionsB.end()) || a->second != b->second)
	    return _error->Error(_("Conflicting values set for option %s regarding source %s %s"), key.c_str(), URI.c_str(), Dist.c_str());
      }
      return true;
   }

   static debReleaseIndex * GetDebReleaseIndexBy(std::vector<metaIndex *> &List, std::string URI,
			   std::string const &Dist, std::map<std::string, std::string> const &Options)
   {
      std::map<std::string, std::string> ReleaseOptions{{
	 {"BASE_URI", constructMetaIndexURI(URI, Dist, "")},
	 {"REPO_URI", URI},
	 {"SITE", ::URI::ArchiveOnly(URI)},
	 {"RELEASE", (Dist == "/") ? "" : Dist},
      }};
      if (GetBoolOption(Options, "allow-insecure", _config->FindB("Acquire::AllowInsecureRepositories")))
	 ReleaseOptions.emplace("ALLOW_INSECURE", "true");
      if (GetBoolOption(Options, "allow-weak", _config->FindB("Acquire::AllowWeakRepositories")))
	 ReleaseOptions.emplace("ALLOW_WEAK", "true");
      if (GetBoolOption(Options, "allow-downgrade-to-insecure", _config->FindB("Acquire::AllowDowngradeToInsecureRepositories")))
	 ReleaseOptions.emplace("ALLOW_DOWNGRADE_TO_INSECURE", "true");
      if (GetBoolOption(Options, "SHADOWED", false))
	 ReleaseOptions.emplace("SHADOWED", "true");

      auto InReleasePath = Options.find("inrelease-path");
      if (InReleasePath != Options.end())
	 ReleaseOptions.emplace("INRELEASE_PATH", InReleasePath->second);

      debReleaseIndex * Deb = nullptr;
      std::string const FileName = URItoFileName(constructMetaIndexURI(URI, Dist, "Release"));
      for (auto const &I: List)
      {
	 // We only worry about debian entries here
	 if (strcmp(I->GetType(), "deb") != 0)
	    continue;

	 auto const D = dynamic_cast<debReleaseIndex*>(I);
	 if (unlikely(D == nullptr))
	    continue;

	 /* This check ensures that there will be only one Release file
	    queued for all the Packages files and Sources files it
	    corresponds to. */
	 if (URItoFileName(D->MetaIndexURI("Release")) == FileName)
	 {
	    if (MapsAreEqual(ReleaseOptions, D->GetReleaseOptions(), URI, Dist) == false)
	       return nullptr;
	    Deb = D;
	    break;
	 }
      }

      // No currently created Release file indexes this entry, so we create a new one.
      if (Deb == nullptr)
      {
	 Deb = new debReleaseIndex(URI, Dist, ReleaseOptions);
	 List.push_back(Deb);
      }
      return Deb;
   }

   protected:
   // This is a duplicate of pkgAcqChangelog::URITemplate()  with some changes to work 
   // on metaIndex instead of cache structures, and using Snapshots
   std::string SnapshotServer(debReleaseIndex const *Rls) const
   {
      if (Rls->GetLabel().empty() && Rls->GetOrigin().empty())
	 return "";
      std::string const serverConfig = "Acquire::Snapshots::URI";
      std::string server;
#define APT_EMPTY_SERVER        \
   if (server.empty() == false) \
   {                            \
      return server;         \
   }
#define APT_CHECK_SERVER(X, Y)                                                                     \
   if (not Rls->Get##X().empty())                                                                  \
   {                                                                                               \
      std::string const specialServerConfig = serverConfig + "::" + Y + #X + "::" + Rls->Get##X(); \
      server = _config->Find(specialServerConfig);                                                 \
      APT_EMPTY_SERVER                                                                             \
   }
      // this way e.g. Debian-Security can fallback to Debian
      APT_CHECK_SERVER(Label, "Override::")
      APT_CHECK_SERVER(Origin, "Override::")

      server = Rls->GetSnapshotsServer();
      APT_EMPTY_SERVER

      APT_CHECK_SERVER(Label, "")
      APT_CHECK_SERVER(Origin, "")
#undef APT_CHECK_SERVER
#undef APT_EMPTY_SERVER
      return "";
   }

   /// \brief Given a hostname, strip one level down, e.g. a.b.c -> .b.c -> .c, this
   ///        allows you to match a.b.c against itself, .b.c, and .c, but not b.c
   static inline std::string NextLevelDomain(std::string Host)
   {
      auto nextDot = Host.find(".", 1);
      if (nextDot == Host.npos)
	 return "";
      return Host.substr(nextDot);
   }
   bool CreateItemInternal(std::vector<metaIndex *> &List, std::string URI,
			   std::string const &Dist, std::string const &Section,
			   bool const &IsSrc, std::map<std::string, std::string> Options) const
   {
      std::string SnapshotAptConf = _config->Find("APT::Snapshot");
      std::string Snapshot = GetSnapshotOption(Options, "snapshot", SnapshotAptConf.empty() ? "" : SnapshotAptConf + "?");
      if (not Snapshot.empty()) {
	 std::map<std::string, std::string> SnapshotOptions = Options;

	 Options.emplace("SHADOWED", "true");

	 ::URI ArchiveURI(URI);
	 // Trim trailing and leading / from the path because we don't want them when calculating snapshot url
	 if (not ArchiveURI.Path.empty() && ArchiveURI.Path[ArchiveURI.Path.length() - 1] == '/')
	    ArchiveURI.Path.erase(ArchiveURI.Path.length() - 1);
	 if (not ArchiveURI.Path.empty() && ArchiveURI.Path[0] == '/')
	    ArchiveURI.Path.erase(0, 1);
	 std::string Server;

	 auto const PreviousDeb = List.empty() ? nullptr : List.back();
	 auto const Deb = GetDebReleaseIndexBy(List, URI, Dist, Options);
	 std::string filename;

	 // The Release file and config based on that should be the ultimate source of truth.
	 if (Deb && ReleaseFileName(Deb, filename))
	 {
	    auto OldDeb = dynamic_cast<debReleaseIndex *>(Deb->UnloadedClone());
	    if (not OldDeb->Load(filename, nullptr))
	       return _error->Error("Cannot identify snapshot server for %s %s - run update without snapshot id first", URI.c_str(), Dist.c_str());
	    Server = SnapshotServer(OldDeb);
	    delete OldDeb;
	 }
	 // We did not find a server based on the release file.
	 // Lookup a fallback based on the host. For a.b.c, this will
	 // try a.b.c, .b.c, and .c to allow generalization for cc.archive.ubuntu.com
	 if (Server.empty())
	 {
	    for (std::string Host = ArchiveURI.Host; not Host.empty(); Host = NextLevelDomain(Host))
	    {
	       Server = _config->Find("Acquire::Snapshots::URI::Host::" + Host);
	       if (not Server.empty())
		  break;
	    }
	 }
	 if (Server.empty() || Server == "no")
	 {
	    if (APT::String::Endswith(Snapshot, "?"))
	    {
	       // Erase the SHADOWED option and remove the release index from the list if we created it.
	       Options.erase("SHADOWED");
	       if (Deb && Deb != PreviousDeb) {
		  assert(List.back() == Deb);
		  List.pop_back();
		  delete Deb;
	       }
	       goto nosnapshot;
	    }
	    if (Server != "no" && filename.empty())
	       return _error->Error("Cannot identify snapshot server for %s %s - run update without snapshot id first", URI.c_str(), Dist.c_str());
	    return _error->Error("Snapshots not supported for %s %s", URI.c_str(), Dist.c_str());
	 }
	 // We have found a server by now, so we enable snapshots for this source.
	 if (APT::String::Endswith(Snapshot, "?"))
	 {
	    Snapshot.pop_back();
	 }

	 assert(not Snapshot.empty());
	 auto SnapshotURI = SubstVar(SubstVar(Server, "@SNAPSHOTID@", Snapshot), "@PATH@", ArchiveURI.Path);

	 if (not CreateItemInternalOne(List, SnapshotURI, Dist, Section, IsSrc, SnapshotOptions))
	    return false;
      }
   nosnapshot:
      if (not CreateItemInternalOne(List, URI, Dist, Section, IsSrc, Options))
	 return false;


      return true;
   }
   bool CreateItemInternalOne(std::vector<metaIndex *> &List, std::string URI,
			   std::string const &Dist, std::string const &Section,
			   bool const &IsSrc, std::map<std::string, std::string> Options) const
   {
      auto const Deb = GetDebReleaseIndexBy(List, URI, Dist, Options);
      if (Deb == nullptr)
	 return false;

      bool const UsePDiffs = GetBoolOption(Options, "pdiffs", _config->FindB("Acquire::PDiffs", true));

      std::string UseByHash = _config->Find("APT::Acquire::By-Hash", "yes");
      UseByHash = _config->Find("Acquire::By-Hash", UseByHash);
      {
	 std::string const host = ::URI(URI).Host;
	 if (host.empty() == false)
	 {
	    UseByHash = _config->Find("APT::Acquire::" + host + "::By-Hash", UseByHash);
	    UseByHash = _config->Find("Acquire::" + host + "::By-Hash", UseByHash);
	 }
	 std::map<std::string, std::string>::const_iterator const opt = Options.find("by-hash");
	 if (opt != Options.end())
	    UseByHash = opt->second;
      }

      auto const entry = Options.find("sourceslist-entry");
      Deb->AddComponent(
	    entry->second,
	    IsSrc,
	    Section,
	    parsePlusMinusTargetOptions(Name, Options),
	    parsePlusMinusArchOptions("arch", Options),
	    parsePlusMinusOptions("lang", Options, APT::Configuration::getLanguages(true)),
	    UsePDiffs,
	    UseByHash
	    );

      if (Deb->SetTrusted(GetTriStateOption(Options, "trusted")) == false ||
	  Deb->SetCheckValidUntil(GetTriStateOption(Options, "check-valid-until")) == false ||
	  Deb->SetValidUntilMax(GetTimeOption(Options, "valid-until-max")) == false ||
	  Deb->SetValidUntilMin(GetTimeOption(Options, "valid-until-min")) == false ||
	  Deb->SetCheckDate(GetTriStateOption(Options, "check-date")) == false ||
	  Deb->SetDateMaxFuture(GetTimeOption(Options, "date-max-future")) == false ||
	  Deb->SetSnapshot(GetSnapshotOption(Options, "snapshot")) == false)
	 return false;

      if (GetBoolOption(Options, "sourceslist-entry-is-deb822", false))
	 Deb->SetFlag(metaIndex::Flag::DEB822);

      std::map<std::string, std::string>::const_iterator const signedby = Options.find("signed-by");
      if (signedby == Options.end())
      {
	 bool alreadySet = false;
	 std::string filename;
	 if (ReleaseFileName(Deb, filename))
	 {
	    auto OldDeb = Deb->UnloadedClone();
	    _error->PushToStack();
	    OldDeb->Load(filename, nullptr);
	    bool const goodLoad = _error->PendingError() == false;
	    _error->RevertToStack();
	    if (goodLoad)
	    {
	       if (OldDeb->GetValidUntil() > 0)
	       {
		  time_t const invalid_since = time(NULL) - OldDeb->GetValidUntil();
		  if (invalid_since <= 0)
		  {
		     Deb->SetSignedBy(OldDeb->GetSignedBy());
		     alreadySet = true;
		  }
	       }
	    }
	    delete OldDeb;
	 }
	 if (alreadySet == false && Deb->SetSignedBy("") == false)
	    return false;
      }
      else
      {
	 if (Deb->SetSignedBy(signedby->second) == false)
	    return false;
      }

      return true;
   }

   debSLTypeDebian(char const * const Name, char const * const Label) : Type(Name, Label)
   {
   }
};
									/*}}}*/
class APT_HIDDEN debSLTypeDeb : public debSLTypeDebian			/*{{{*/
{
   public:

   bool CreateItem(std::vector<metaIndex *> &List, std::string const &URI,
		   std::string const &Dist, std::string const &Section,
		   std::map<std::string, std::string> const &Options) const APT_OVERRIDE
   {
      return CreateItemInternal(List, URI, Dist, Section, false, Options);
   }

   debSLTypeDeb() : debSLTypeDebian("deb", "Debian binary tree")
   {
   }
};
									/*}}}*/
class APT_HIDDEN debSLTypeDebSrc : public debSLTypeDebian		/*{{{*/
{
   public:

   bool CreateItem(std::vector<metaIndex *> &List, std::string const &URI,
		   std::string const &Dist, std::string const &Section,
		   std::map<std::string, std::string> const &Options) const APT_OVERRIDE
   {
      return CreateItemInternal(List, URI, Dist, Section, true, Options);
   }

   debSLTypeDebSrc() : debSLTypeDebian("deb-src", "Debian source tree")
   {
   }
};
									/*}}}*/

APT_HIDDEN debSLTypeDeb _apt_DebType;
APT_HIDDEN debSLTypeDebSrc _apt_DebSrcType;