add insecure (and weak) allow-options for sources.list

Weak had no dedicated option before and Insecure and Downgrade were both
global options, which given the effect they all have on security is
rather bad. Setting them for individual repositories only isn't great
but at least slightly better and also more consistent with other
settings for repositories.

1 files changed, 43 insertions, 9 deletions

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index 63b3c9a1f..a4b1d4897 100644
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -175,7 +175,7 @@ static void ReportMirrorFailureToCentral(pkgAcquire::Item const &I, std::string
 }
 									/*}}}*/
 
-static bool MessageInsecureRepository(bool const isError, char const * const msg, std::string const &repo)/*{{{*/
+static APT_NONNULL(2) bool MessageInsecureRepository(bool const isError, char const * const msg, std::string const &repo)/*{{{*/
 {
    std::string m;
    strprintf(m, msg, repo.c_str());
@@ -195,7 +195,28 @@ static bool MessageInsecureRepository(bool const isError, char const * const msg
 									/*}}}*/
 // AllowInsecureRepositories						/*{{{*/
 enum class InsecureType { UNSIGNED, WEAK, NORELEASE };
-static bool APT_NONNULL(3, 4, 5) AllowInsecureRepositories(InsecureType msg, std::string const &repo,
+static bool TargetIsAllowedToBe(IndexTarget const &Target, InsecureType const type)
+{
+   if (_config->FindB("Acquire::AllowInsecureRepositories"))
+      return true;
+
+   if (Target.OptionBool(IndexTarget::ALLOW_INSECURE))
+      return true;
+
+   switch (type)
+   {
+      case InsecureType::UNSIGNED: break;
+      case InsecureType::NORELEASE: break;
+      case InsecureType::WEAK:
+	 if (_config->FindB("Acquire::AllowWeakRepositories"))
+	    return true;
+	 if (Target.OptionBool(IndexTarget::ALLOW_WEAK))
+	    return true;
+	 break;
+   }
+   return false;
+}
+static bool APT_NONNULL(3, 4, 5) AllowInsecureRepositories(InsecureType const msg, std::string const &repo,
       metaIndex const * const MetaIndexParser, pkgAcqMetaClearSig * const TransactionManager, pkgAcquire::Item * const I)
 {
    // we skip weak downgrades as its unlikely that a repository gets really weaker –
@@ -213,7 +234,8 @@ static bool APT_NONNULL(3, 4, 5) AllowInsecureRepositories(InsecureType msg, std
 	    case InsecureType::NORELEASE: msgstr = _("The repository '%s' does no longer have a Release file."); break;
 	    case InsecureType::WEAK: /* unreachable */ break;
 	 }
-	 if (_config->FindB("Acquire::AllowDowngradeToInsecureRepositories"))
+	 if (_config->FindB("Acquire::AllowDowngradeToInsecureRepositories") ||
+	       TransactionManager->Target.OptionBool(IndexTarget::ALLOW_DOWNGRADE_TO_INSECURE))
 	 {
 	    // meh, the users wants to take risks (we still mark the packages
 	    // from this repository as unauthenticated)
@@ -241,7 +263,7 @@ static bool APT_NONNULL(3, 4, 5) AllowInsecureRepositories(InsecureType msg, std
       case InsecureType::WEAK: msgstr = _("The repository '%s' provides only weak security information."); break;
    }
 
-   if (_config->FindB("Acquire::AllowInsecureRepositories") == true)
+   if (TargetIsAllowedToBe(TransactionManager->Target, msg) == true)
    {
       MessageInsecureRepository(false, msgstr, repo);
       return true;
@@ -277,7 +299,20 @@ APT_CONST bool pkgAcqTransactionItem::HashesRequired() const
       we can at least trust them for integrity of the download itself.
       Only repositories without a Release file can (obviously) not have
       hashes – and they are very uncommon and strongly discouraged */
-   return TransactionManager->MetaIndexParser->GetLoadedSuccessfully() == metaIndex::TRI_YES;
+   if (TransactionManager->MetaIndexParser->GetLoadedSuccessfully() != metaIndex::TRI_YES)
+      return false;
+   if (TargetIsAllowedToBe(Target, InsecureType::WEAK))
+   {
+      /* If we allow weak hashes, we check that we have some (weak) and then
+         declare hashes not needed. That will tip us in the right direction
+	 as if hashes exist, they will be used, even if not required */
+      auto const hsl = GetExpectedHashes();
+      if (hsl.usable())
+	 return true;
+      if (hsl.empty() == false)
+	 return false;
+   }
+   return true;
 }
 HashStringList pkgAcqTransactionItem::GetExpectedHashes() const
 {
@@ -1333,7 +1368,7 @@ void pkgAcqMetaClearSig::QueueIndexes(bool const verify)			/*{{{*/
 	    auto const hashes = GetExpectedHashesFor(Target.MetaKey);
 	    if (hashes.empty() == false)
 	    {
-	       if (hashes.usable() == false)
+	       if (hashes.usable() == false && TargetIsAllowedToBe(TransactionManager->Target, InsecureType::WEAK) == false)
 	       {
 		  new CleanupItem(Owner, TransactionManager, Target);
 		  _error->Warning(_("Skipping acquire of configured file '%s' as repository '%s' provides only weak security information for it"),
@@ -1525,8 +1560,7 @@ pkgAcqMetaClearSig::pkgAcqMetaClearSig(pkgAcquire * const Owner,	/*{{{*/
       IndexTarget const &DetachedDataTarget, IndexTarget const &DetachedSigTarget,
       metaIndex * const MetaIndexParser) :
    pkgAcqMetaIndex(Owner, this, ClearsignedTarget, DetachedSigTarget),
-   d(NULL), ClearsignedTarget(ClearsignedTarget),
-   DetachedDataTarget(DetachedDataTarget),
+   d(NULL), DetachedDataTarget(DetachedDataTarget),
    MetaIndexParser(MetaIndexParser), LastMetaIndexParser(NULL)
 {
    // index targets + (worst case:) Release/Release.gpg
@@ -1640,7 +1674,7 @@ void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig c
       if(CheckStopAuthentication(this, Message))
          return;
 
-      if(AllowInsecureRepositories(InsecureType::UNSIGNED, ClearsignedTarget.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)
+      if(AllowInsecureRepositories(InsecureType::UNSIGNED, Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)
       {
 	 Status = StatDone;