Do not allow going from authenticated to unauthenticated repo

Also rework the way we load the Release file, so it only after
Release.gpg verified the Release file. The rational is that we
never want to load untrusted data into our parsers. Only stuff
verified with gpg or by its hashes get loaded. To load untrusted
data you now need to use apt-get update --allow-unauthenticated.

1 files changed, 64 insertions, 15 deletions

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index 4e843ecaf..7fad5605d 100644
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -193,6 +193,14 @@ bool pkgAcquire::Item::RenameOnError(pkgAcquire::Item::RenameOnErrorState const
 	 Status = StatError;
 	 // do not report as usually its not the mirrors fault, but Portal/Proxy
 	 break;
+      case SignatureError:
+	 ErrorText = _("Signature error");
+	 Status = StatError;
+	 break;
+      case NotClearsigned:
+         ErrorText = _("Does not start with a cleartext signature");
+	 Status = StatError;
+	 break;
    }
    return false;
 }
@@ -1307,6 +1315,8 @@ void pkgAcqMetaBase::AbortTransaction()
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
       std::clog << "AbortTransaction: " << TransactionManager << std::endl;
 
+   // ensure the toplevel is in error state too
+   Status = pkgAcquire::Item::StatError;
    for (std::vector<Item*>::iterator I = Transaction.begin();
         I != Transaction.end(); ++I)
    {
@@ -1407,6 +1417,7 @@ pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,          		/*{{{*/
 			     indexRecords* MetaIndexParser) :
    pkgAcqMetaBase(Owner, HashStringList(), TransactionManager), RealURI(URI), 
    MetaIndexParser(MetaIndexParser), MetaIndexFile(MetaIndexFile),
+   URIDesc(URIDesc), ShortDesc(ShortDesc),
    IndexTargets(IndexTargets), AuthPass(false), IMSHit(false)
 {
    DestFile = _config->FindDir("Dir::State::lists") + "partial/";
@@ -1505,13 +1516,35 @@ void pkgAcqMetaSig::Done(string Message,unsigned long long Size, HashStringList
       DestFile += URItoFileName(RealURI);
    }
 
-   Complete = true;
+   // we parse the MetaIndexFile here because at this point we can
+   // trust the data
+   if(AuthPass == true)
+   {
+      // load indexes and queue further downloads
+      MetaIndexParser->Load(MetaIndexFile);
+      ((pkgAcqMetaIndex*)TransactionManager)->QueueIndexes(true);
+   }
 
+   Complete = true;
 }
 									/*}}}*/
 void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)/*{{{*/
 {
    string Final = _config->FindDir("Dir::State::lists") + URItoFileName(RealURI);
+   
+   // FIXME: meh, this is not really elegant
+   string InReleaseURI = RealURI.replace(RealURI.rfind("Release.gpg"), 12,
+                                         "InRelease");
+   string FinalInRelease = _config->FindDir("Dir::State::lists") + URItoFileName(InReleaseURI);
+
+   if(RealFileExists(Final) || RealFileExists(FinalInRelease))
+   {
+      _error->Error("The repository '%s' is no longer signed.",
+                    URIDesc.c_str());
+      Rename(MetaIndexFile, MetaIndexFile+".FAILED");
+      TransactionManager->AbortTransaction();
+      return;
+   }
 
    // this ensures that any file in the lists/ dir is removed by the
    // transaction
@@ -1527,6 +1560,19 @@ void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)/*{{{*/
          return;
    }
 
+   // only allow going further if the users explicitely wants it
+   if(_config->FindB("APT::Get::AllowUnauthenticated", false))
+   {
+      _error->Warning("Please use --allow-unauthenticated");
+   } 
+   else 
+   {
+      // we parse the indexes here because at this point the user wanted
+      // a repository that may potentially harm him
+      MetaIndexParser->Load(MetaIndexFile);
+      ((pkgAcqMetaIndex*)TransactionManager)->QueueIndexes(true);
+   }
+
    // FIXME: this is used often (e.g. in pkgAcqIndexTrans) so refactor
    if (Cnf->LocalOnly == true || 
        StringToBool(LookupTag(Message,"Transient-Failure"),false) == false)
@@ -1547,6 +1593,7 @@ pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,			/*{{{*/
 				 const vector<IndexTarget*>* IndexTargets,
 				 indexRecords* MetaIndexParser) :
    pkgAcqMetaBase(Owner, HashStringList(), TransactionManager), RealURI(URI), IndexTargets(IndexTargets),
+   URIDesc(URIDesc), ShortDesc(ShortDesc),
    MetaIndexParser(MetaIndexParser), AuthPass(false), IMSHit(false),
    MetaIndexSigURI(MetaIndexSigURI), MetaIndexSigURIDesc(MetaIndexSigURIDesc),
    MetaIndexSigShortDesc(MetaIndexSigShortDesc)
@@ -1619,13 +1666,7 @@ void pkgAcqMetaIndex::Done(string Message,unsigned long long Size,HashStringList
          // Still more retrieving to do
          return;
 
-      if (SigFile == "")
-      {
-         // load indexes, the signature will downloaded afterwards
-         MetaIndexParser->Load(DestFile);
-         QueueIndexes(true);
-      }
-      else
+      if (SigFile != "")
       {
          // There was a signature file, so pass it to gpgv for
          // verification
@@ -1952,7 +1993,8 @@ void pkgAcqMetaIndex::Failed(string Message,
 
    /* Always move the meta index, even if gpgv failed. This ensures
     * that PackageFile objects are correctly filled in */
-   if (FileExists(DestFile)) {
+   if (FileExists(DestFile)) 
+   {
       string FinalFile = _config->FindDir("Dir::State::lists");
       FinalFile += URItoFileName(RealURI);
       /* InRelease files become Release files, otherwise
@@ -1970,13 +2012,19 @@ void pkgAcqMetaIndex::Failed(string Message,
       DestFile = FinalFile;
    }
 
-   // warn if the repository is unsinged
-   _error->Warning(_("The data from '%s' is not signed. Packages "
-                     "from that repository can not be authenticated."),
-                   URIDesc.c_str());
    // No Release file was present, or verification failed, so fall
    // back to queueing Packages files without verification
-   QueueIndexes(false);
+   // only allow going further if the users explicitely wants it
+   if(_config->FindB("APT::Get::AllowUnauthenticated", false))
+   {
+      // warn if the repository is unsinged
+      _error->Warning(_("The data from '%s' is not signed. Packages "
+                     "from that repository can not be authenticated."),
+                   URIDesc.c_str());
+      _error->Warning("Please use --allow-unauthenticated");
+   } else {
+      QueueIndexes(false);
+   }
 }
 									/*}}}*/
 
@@ -2060,7 +2108,8 @@ void pkgAcqMetaClearSig::Done(std::string Message,unsigned long long Size,
    if (FileExists(DestFile) && !StartsWithGPGClearTextSignature(DestFile))
    {
       pkgAcquire::Item::Failed(Message, Cnf);
-      ErrorText = _("Does not start with a cleartext signature");
+      RenameOnError(NotClearsigned);
+      TransactionManager->AbortTransaction();
       return;
    }
    pkgAcqMetaIndex::Done(Message, Size, Hashes, Cnf);