methods: Add new sqv method

The new sqv method uses sequoia's sqv tool to verify files. The
tool's interface is quite simple: It returns 0 on success, and
prints one line per good signer with the fingerprint.

sqv has a configurable crypto policy. We have defined apt-specific
override mechanisms for sequoia's standard policy, allowing both
users, distributions, and apt package to provide overrides for
Sequoia's default policy in meaningful ways.

The sqv method will be built and be the standard method for
verifying OpenPGP signatures provided that `sqv` is in the
PATH during building. It is not built if there was no sqv
at build time, so you need a rebuild to enable sqv later
on.

On the flip side, the gpgv method is always built, but it
does need to be always built: If APT::Key::GPGVCommand is
set, we need to fallback to it - this is important to
support existing users of that interface such as
mmdebstrap. Also we want to fall back to it when /usr/bin/sqv
disappears - for example in our CI :D

A couple of concessions have been made for test suite purposes:

- Failure to split a clearsigned file only shows the summary,
  as the gpgv method also only showed it, and no details why
  it failed.
- We write "Got GOODSIG <fingerprint>" in debug mode to mimic
  the gpgv code to keep the test suite happy.

- In various places in the test suite we assert minimal output
  from sqv, but sqv's human output is not intended to be stable.
  This will incur additional work when it breaks. However we do
  not _parse_ the output, so actual operation of apt is unaffected.

A couple of things are suboptimal here:

- We are still doing clearsigned splitting ourselves. sqv only
  has support for detached signatures right now, whereas sqopv
  has support for clearsigned files as well (but sqopv does not
  provide any reasons for why signature verification fails or
  means to set a policy).

- Deprecation of algorithms happens on a timebomb basis in
  sequoia. We have no means to give users warnings ahead of
  time if their configuration is outdated.

We have implemented various bits that probably should be going away:

- Fallback to trusted.gpg
  This is just annoying...
- Support for fingerprints in Signed-By (no subkey matching though)
  The extra work here is arguably less compared to gpgv.
- Check the keyring for correctness.
  With Signed-By everywhere, we should just error out rather than
  skip broken keyrings.

Moo

13 files changed, 456 insertions, 49 deletions

diff --git a/CMake/config.h.in b/CMake/config.h.in
index ced74d8d8..b2c5eac56 100644
--- a/CMake/config.h.in
+++ b/CMake/config.h.in
@@ -85,3 +85,4 @@
 
 #cmakedefine DEFAULT_PAGER "${DEFAULT_PAGER}"
 #cmakedefine PAGER_ENV "${PAGER_ENV}"
+#cmakedefine SQV_EXECUTABLE "${SQV_EXECUTABLE}"
diff --git a/CMakeLists.txt b/CMakeLists.txt
index af2ec3a86..03796e09c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -46,6 +46,7 @@ find_package(Iconv REQUIRED)
 find_package(Perl REQUIRED)
 
 find_program(TRIEHASH_EXECUTABLE NAMES triehash)
+find_program(SQV_EXECUTABLE NAMES sqv)
 
 if (NOT TRIEHASH_EXECUTABLE)
   message(FATAL_ERROR "Could not find triehash executable")
diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index 12524778e..69644883b 100644
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -1423,7 +1423,15 @@ string pkgAcqMetaBase::Custom600Headers() const
 void pkgAcqMetaBase::QueueForSignatureVerify(pkgAcqTransactionItem * const I, std::string const &File, std::string const &Signature)
 {
    AuthPass = true;
+#ifdef SQV_EXECUTABLE
+   if (not _config->Find("APT::Key::GPGVCommand").empty() || not FileExists(SQV_EXECUTABLE))
+      I->Desc.URI = "gpgv:" + pkgAcquire::URIEncode(Signature);
+   else {
+      I->Desc.URI = "sqv:" + pkgAcquire::URIEncode(Signature);
+   }
+#else
    I->Desc.URI = "gpgv:" + pkgAcquire::URIEncode(Signature);
+#endif
    I->DestFile = File;
    QueueURI(I->Desc);
    I->SetActiveSubprocess("gpgv");
diff --git a/apt-pkg/contrib/gpgv.cc b/apt-pkg/contrib/gpgv.cc
index 7b0a0d240..48d31a44c 100644
--- a/apt-pkg/contrib/gpgv.cc
+++ b/apt-pkg/contrib/gpgv.cc
@@ -169,7 +169,7 @@ static bool CheckGPGV(std::unordered_map<std::string, std::forward_list<std::str
 
 /// Verifies a file containing a detached signature has the right format
 /// @return 0 if succesful, or an exit code for ExecGPGV otherwise.
-static int VerifyDetachedSignatureFile(std::string FileGPG, int fd[2], int statusfd = -1)
+static int VerifyDetachedSignatureFile(std::string const &FileGPG, int fd[2], int statusfd = -1)
 {
    auto detached = make_unique_FILE(FileGPG, "r");
    if (detached.get() == nullptr)
@@ -211,10 +211,17 @@ static int VerifyDetachedSignatureFile(std::string FileGPG, int fd[2], int statu
 	 }
       }
    }
-   if (found_signatures == 0 && statusfd != -1)
+   if (found_signatures == 0)
    {
-      auto const errtag = "[GNUPG:] NODATA\n";
-      FileFd::Write(fd[1], errtag, strlen(errtag));
+      if (statusfd != -1 && fd)
+      {
+	 auto const errtag = "[GNUPG:] NODATA\n";
+	 FileFd::Write(fd[1], errtag, strlen(errtag));
+      }
+      else
+      {
+	 _error->Error("Signed file isn't valid, got 'NODATA' (does the network require authentication?)");
+      }
       // guess if this is a binary signature, we never officially supported them,
       // but silently accepted them via passing them unchecked to gpgv
       if (found_badcontent)
@@ -247,6 +254,11 @@ static int VerifyDetachedSignatureFile(std::string FileGPG, int fd[2], int statu
    return 0;
 }
 
+bool VerifyDetachedSignatureFile(std::string const &DetachedSignatureFileName)
+{
+   return VerifyDetachedSignatureFile(DetachedSignatureFileName, nullptr, -1) == 0;
+}
+
 std::pair<std::string, std::forward_list<std::string>> APT::Internal::FindGPGV(bool Debug)
 {
    static thread_local std::unordered_map<std::string, std::forward_list<std::string>> checkedCommands;
diff --git a/apt-pkg/contrib/gpgv.h b/apt-pkg/contrib/gpgv.h
index d4520f3a2..0b84f6bb7 100644
--- a/apt-pkg/contrib/gpgv.h
+++ b/apt-pkg/contrib/gpgv.h
@@ -96,5 +96,14 @@ APT_PUBLIC bool SplitClearSignedFile(std::string const &InFile, FileFd * const C
  */
 APT_PUBLIC bool OpenMaybeClearSignedFile(std::string const &ClearSignedFileName, FileFd &MessageFile);
 
+/** \brief verifiy a detached signature file for correctness.
+ *
+ * We want to expect unavoided content. This may set an error when returning false
+ * but it might not necessarily do so (in case of empty signature file).
+ *
+ * @return true if the detached signature files contains ASCII-armored signatures, otherwise false
+ */
+APT_PUBLIC bool VerifyDetachedSignatureFile(std::string const &DetachedSignatureFileName);
+
 APT_PUBLIC bool IsAssertedPubKeyAlgo(std::string const &pkstr, std::string const &option);
 #endif
diff --git a/methods/CMakeLists.txt b/methods/CMakeLists.txt
index beb08a81d..161cd91d1 100644
--- a/methods/CMakeLists.txt
+++ b/methods/CMakeLists.txt
@@ -8,6 +8,11 @@ add_executable(file file.cc)
 add_executable(copy copy.cc)
 add_executable(store store.cc)
 add_executable(gpgv gpgv.cc)
+if (SQV_EXECUTABLE)
+add_executable(sqv sqv.cc)
+install(TARGETS sqv
+        RUNTIME DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}/apt/methods)
+endif()
 add_executable(cdrom cdrom.cc)
 add_executable(http http.cc basehttp.cc $<TARGET_OBJECTS:connectlib>)
 add_executable(mirror mirror.cc)
@@ -23,7 +28,7 @@ target_link_libraries(http OpenSSL::SSL $<$<BOOL:${SYSTEMD_FOUND}>:${SYSTEMD_LIB
 target_link_libraries(rred apt-private)
 
 # Install the library
-install(TARGETS file copy store gpgv cdrom http rred mirror
+install(TARGETS file copy store cdrom gpgv http rred mirror
         RUNTIME DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}/apt/methods)
 
 add_links(${CMAKE_INSTALL_LIBEXECDIR}/apt/methods mirror mirror+http mirror+https mirror+file mirror+copy)
diff --git a/methods/sqv.cc b/methods/sqv.cc
new file mode 100644
index 000000000..63ccdc08f
--- /dev/null
+++ b/methods/sqv.cc
@@ -0,0 +1,346 @@
+#include <config.h>
+
+#include "aptmethod.h"
+#include <apt-pkg/gpgv.h>
+#include <apt-pkg/strutl.h>
+#include <iterator>
+#include <optional>
+#include <ostream>
+#include <sstream>
+
+using std::string;
+using std::vector;
+
+class SQVMethod : public aptMethod
+{
+   private:
+   std::optional<std::string> policy{};
+   void SetPolicy();
+   bool VerifyGetSigners(const char *file, const char *outfile,
+			 vector<string> keyFiles,
+			 vector<string> &signers);
+
+   protected:
+   virtual bool URIAcquire(std::string const &Message, FetchItem *Itm) APT_OVERRIDE;
+
+   public:
+   SQVMethod();
+};
+
+SQVMethod::SQVMethod() : aptMethod("sqv", "1.1", SingleInstance | SendConfig | SendURIEncoded)
+{
+}
+
+void SQVMethod::SetPolicy()
+{
+   constexpr const char *policies[] = {
+      // APT overrides
+      "APT_SEQUOIA_CRYPTO_POLICY",
+      "/etc/crypto-policies/back-ends/apt-sequoia.config",
+      "/var/lib/crypto-config/profiles/current/apt-sequoia.config",
+      // Sequoia overrides
+      "SEQUOIA_CRYPTO_POLICY",
+      "/etc/crypto-policies/back-ends/sequoia.config",
+      "/var/lib/crypto-config/profiles/current/sequoia.config",
+      // Fallback APT defaults
+      "/usr/share/apt/default-sequoia.config",
+   };
+
+   if (policy)
+      return;
+
+   policy = "";
+
+   for (auto policy : policies)
+   {
+      if (not strchr(policy, '/'))
+      {
+	 if (auto value = getenv(policy))
+	 {
+	    this->policy = value;
+	    break;
+	 }
+      }
+      else if (FileExists(policy))
+      {
+	 this->policy = policy;
+	 break;
+      }
+   }
+
+   if (not policy->empty())
+   {
+      if (DebugEnabled())
+	 std::clog << "Setting SEQUOIA_CRYPTO_POLICY=" << *policy << std::endl;
+      setenv("SEQUOIA_CRYPTO_POLICY", policy->c_str(), 1);
+   }
+}
+bool SQVMethod::VerifyGetSigners(const char *file, const char *outfile,
+				 vector<string> keyFiles,
+				 vector<string> &signers)
+{
+   bool const Debug = DebugEnabled();
+
+   std::vector<std::string> args;
+
+   SetPolicy();
+
+   args.push_back(SQV_EXECUTABLE);
+   auto dearmorKeyOrCheckFormat = [&](std::string const &k) -> bool
+   {
+      _error->PushToStack();
+      FileFd keyFd(k, FileFd::ReadOnly);
+      _error->RevertToStack();
+      if (not keyFd.IsOpen())
+	 return _error->Warning("The key(s) in the keyring %s are ignored as the file is not readable by user executing gpgv.\n", k.c_str());
+      else if (APT::String::Endswith(k, ".asc"))
+      {
+	 std::string b64msg;
+	 int state = 0;
+	 for (std::string line; keyFd.ReadLine(line);)
+	 {
+	    line = APT::String::Strip(line);
+	    if (APT::String::Startswith(line, "-----BEGIN PGP PUBLIC KEY BLOCK-----"))
+	       state = 1;
+	    else if (state == 1 && line == "")
+	       state = 2;
+	    else if (state == 2 && line != "" && line[0] != '=' && line[0] != '-')
+	       b64msg += line;
+	    else if (APT::String::Startswith(line, "-----END"))
+	       state = 3;
+	 }
+	 if (state != 3)
+	    goto err;
+
+	 return true;
+      }
+      else
+      {
+	 unsigned char c;
+	 if (not keyFd.Read(&c, sizeof(c)))
+	    goto err;
+	 // Identify the leading byte of an OpenPGP public key packet
+	 // 0x98 -- old-format OpenPGP public key packet, up to 255 octets
+	 // 0x99 -- old-format OpenPGP public key packet, 256-65535 octets
+	 // 0xc6 -- new-format OpenPGP public key packet, any length
+	 if (c != 0x98 && c != 0x99 && c != 0xc6)
+	    goto err;
+	 return true;
+      }
+   err:
+      return _error->Warning("The key(s) in the keyring %s are ignored as the file has an unsupported filetype.", k.c_str());
+   };
+   if (keyFiles.empty())
+   {
+      auto Parts = GetListOfFilesInDir(_config->FindDir("Dir::Etc::TrustedParts"), std::vector<std::string>{"gpg", "asc"}, true);
+      for (auto &Part : Parts)
+      {
+	 if (Debug)
+	    std::clog << "Trying TrustedPart: " << Part << std::endl;
+	 if (struct stat st; stat(Part.c_str(), &st) != 0 || st.st_size == 0)
+	    continue;
+	 if (not dearmorKeyOrCheckFormat(Part))
+	 {
+	    std::string msg;
+	    _error->PopMessage(msg);
+	    if (not msg.empty())
+	       Warning(std::move(msg));
+	    continue;
+	 }
+	 keyFiles.push_back(Part);
+      }
+   }
+
+   if (keyFiles.empty())
+      return _error->Error("The signatures couldn't be verified because no keyring is specified");
+
+   for (auto const &keyring : keyFiles)
+   {
+      args.push_back("--keyring");
+      args.push_back(keyring);
+   }
+
+   FileFd signatureFd;
+   FileFd messageFd;
+   DEFER([&]
+	 {
+	 if (signatureFd.IsOpen()) RemoveFile("RemoveSignature", signatureFd.Name());
+	 if (messageFd.IsOpen()) RemoveFile("RemoveMessage", messageFd.Name()); });
+
+   if (strcmp(file, outfile) == 0)
+   {
+      if (GetTempFile("apt.sig", false, &signatureFd) == nullptr)
+	 return false;
+      if (GetTempFile("apt.data", false, &messageFd) == nullptr)
+	 return false;
+
+      // FIXME: The test suite only expects the final message.
+      _error->PushToStack();
+      if (signatureFd.Failed() || messageFd.Failed() ||
+	  not SplitClearSignedFile(file, &messageFd, nullptr, &signatureFd))
+	 return _error->RevertToStack(), _error->Error("Splitting up %s into data and signature failed", file);
+      _error->RevertToStack();
+
+      args.push_back(signatureFd.Name());
+      args.push_back(messageFd.Name());
+   }
+   else
+   {
+      if (not VerifyDetachedSignatureFile(file))
+	 return false;
+      args.push_back(file);
+      args.push_back(outfile);
+   }
+
+   // FIXME: Use a select() loop
+   FileFd sqvout;
+   FileFd sqverr;
+   if (GetTempFile("apt.sqvout", false, &sqvout) == nullptr)
+      return "Internal error: Cannot create temporary file";
+
+   DEFER([&]
+	 { RemoveFile("CleanSQVOut", sqvout.Name()); });
+
+   if (GetTempFile("apt.sqverr", false, &sqverr) == nullptr)
+      return "Internal error: Cannot create temporary file";
+
+   DEFER([&]
+	 { RemoveFile("CleanSQVErr", sqverr.Name()); });
+
+   // Translate the argument list to a C array. This should happen before
+   // the fork so we don't allocate money between fork() and execvp().
+   if (Debug)
+      std::clog << "Executing " << APT::String::Join(args, " ") << std::endl;
+   std::vector<const char *> cArgs;
+   cArgs.reserve(args.size() + 1);
+   for (auto const &arg : args)
+      cArgs.push_back(arg.c_str());
+   cArgs.push_back(nullptr);
+   pid_t pid = ExecFork({sqvout.Fd(), sqverr.Fd()});
+   if (pid < 0)
+      return _error->Errno("VerifyGetSigners", "Couldn't spawn new process");
+   else if (pid == 0)
+   {
+      dup2(sqvout.Fd(), STDOUT_FILENO);
+      dup2(sqverr.Fd(), STDERR_FILENO);
+      execvp(cArgs[0], (char **)&cArgs[0]);
+      _exit(123);
+   }
+
+   int status;
+   waitpid(pid, &status, 0);
+   sqverr.Seek(0);
+   sqvout.Seek(0);
+
+   if (Debug == true)
+      ioprintf(std::clog, "sqv exited with status %i\n", WEXITSTATUS(status));
+   if (WEXITSTATUS(status) != 0)
+   {
+      std::string msg;
+      for (std::string err; sqverr.ReadLine(err);)
+	 msg.append(err).append("\n");
+      return _error->Error(_("Sub-process %s returned an error code (%u), error message is:\n%s"), cArgs[0], WEXITSTATUS(status), msg.c_str());
+   }
+
+   for (std::string signer; sqvout.ReadLine(signer);)
+   {
+      if (Debug)
+	 std::clog << "Got GOODSIG " << signer << std::endl;
+      signers.push_back(signer);
+   }
+
+   return true;
+}
+
+static std::string GenerateKeyFile(std::string const key)
+{
+   FileFd fd;
+   GetTempFile("apt-key.XXXXXX.asc", false, &fd);
+   fd.Write(key.data(), key.size());
+   return fd.Name();
+}
+
+bool SQVMethod::URIAcquire(std::string const &Message, FetchItem *Itm)
+{
+   URI const Get(Itm->Uri);
+   std::string const Path = DecodeSendURI(Get.Host + Get.Path); // To account for relative paths
+
+   std::vector<std::string> Signers, keyFpts, keyFiles;
+   struct TemporaryFile
+   {
+      std::string name = "";
+      ~TemporaryFile() { RemoveFile("~TemporaryFile", name); }
+   } tmpKey;
+
+   std::string SignedBy = DeQuoteString(LookupTag(Message, "Signed-By"));
+
+   if (SignedBy.find("-----BEGIN PGP PUBLIC KEY BLOCK-----") != std::string::npos)
+   {
+      tmpKey.name = GenerateKeyFile(SignedBy);
+      keyFiles.emplace_back(tmpKey.name);
+   }
+   else
+   {
+      for (auto &&key : VectorizeString(SignedBy, ','))
+	 if (key.empty() == false && key[0] == '/')
+	    keyFiles.emplace_back(std::move(key));
+	 else
+	    keyFpts.emplace_back(std::move(key));
+   }
+
+   // Run apt-key on file, extract contents and get the key ID of the signer
+   VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(), keyFiles, Signers);
+   if (_error->PendingError())
+   {
+      // Legacy fallback to trusted.gpg
+      auto trusted = _config->FindFile("Dir::Etc::Trusted");
+      _error->PushToStack();
+      VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(), {trusted}, Signers);
+      bool error = _error->PendingError();
+      _error->RevertToStack();
+      if (error)
+	 return false;
+      std::string warning;
+      strprintf(warning,
+		_("Key is stored in legacy trusted.gpg keyring (%s). Use Signed-By instead. See the USER CONFIGURATION section in apt-secure(8) for details."),
+		trusted.c_str());
+      Warning(std::move(warning));
+   }
+
+   if (Signers.empty())
+      return _error->Error("No good signature");
+
+   if (not keyFpts.empty())
+   {
+      Signers.erase(std::remove_if(Signers.begin(), Signers.end(), [&](std::string const &signer)
+				   {
+	 bool allowedSigner = std::find(keyFpts.begin(), keyFpts.end(), signer) != keyFpts.end();
+	 if (not allowedSigner && DebugEnabled())
+	       std::cerr << "NoPubKey: GOODSIG " << signer << "\n";
+	 return not allowedSigner; }),
+		    Signers.end());
+
+      if (Signers.empty())
+      {
+	 if (keyFpts.size() > 1)
+	    return _error->Error(_("No good signature from required signers: %s"), APT::String::Join(keyFpts, ", ").c_str());
+	 return _error->Error(_("No good signature from required signer: %s"), APT::String::Join(keyFpts, ", ").c_str());
+      }
+   }
+   std::unordered_map<std::string, std::string> fields;
+   fields.emplace("URI", Itm->Uri);
+   fields.emplace("Filename", Itm->DestFile);
+   fields.emplace("Signed-By", APT::String::Join(Signers, "\n"));
+   SendMessage("201 URI Done", std::move(fields));
+   Dequeue();
+
+   if (DebugEnabled())
+      std::clog << "sqv succeeded\n";
+
+   return true;
+}
+
+int main()
+{
+   return SQVMethod().Run();
+}
diff --git a/test/integration/test-apt-update-ims b/test/integration/test-apt-update-ims
index 1894c3adf..101c2f298 100755
--- a/test/integration/test-apt-update-ims
+++ b/test/integration/test-apt-update-ims
@@ -48,7 +48,7 @@ runtest() {
 
     # ensure that we still do a hash check for other files on ims hit of Release
     if grep -q '^Hit:[0-9]\+ .* InRelease$' expected.output || ! grep -q '^Ign:[0-9]\+ .* Release\(\.gpg\)\?$' expected.output; then
-	    $TEST aptget update -o Debug::Acquire::gpgv=1 $APTOPT
+	    $TEST aptget update -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1 $APTOPT
 	    cp rootdir/tmp/${TEST}.output goodsign.output
 	    testfileequal 'listsdir.lst' "$(listcurrentlistsdirectory)"
 	    testsuccess grep '^Got GOODSIG ' goodsign.output
diff --git a/test/integration/test-apt-update-nofallback b/test/integration/test-apt-update-nofallback
index 18f12b1e3..c9ee75756 100755
--- a/test/integration/test-apt-update-nofallback
+++ b/test/integration/test-apt-update-nofallback
@@ -198,9 +198,16 @@ test_inrelease_to_invalid_inrelease()
     sed -i 's/^Codename:.*/Codename: evil!/' "$APTARCHIVE/dists/unstable/InRelease"
     inject_evil_package
 
-    testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable InRelease: The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>
+    if test -e /usr/bin/sqv; then
+        # FIXME: Do not assert sqv output
+        testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable InRelease: Sub-process /usr/bin/sqv returned an error code (1), error message is: Verifying signature:            Message has been manipulated
+W: Failed to fetch file:${APTARCHIVE}/dists/unstable/InRelease  Sub-process /usr/bin/sqv returned an error code (1), error message is: Verifying signature:            Message has been manipulated
+W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq
+    else
+        testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable InRelease: The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>
 W: Failed to fetch file:${APTARCHIVE}/dists/unstable/InRelease  The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>
 W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq
+    fi
 
     # ensure we keep the repo
     testfailure grep 'evil' rootdir/var/lib/apt/lists/*InRelease
@@ -218,10 +225,16 @@ test_release_gpg_to_invalid_release_release_gpg()
     # now subvert Release do no longer verify
     echo "Some evil data" >> "$APTARCHIVE/dists/unstable/Release"
     inject_evil_package
-
-    testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable Release: The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>
+    if test -e /usr/bin/sqv; then
+        # FIXME: Do not assert sqv output
+        testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable Release: Sub-process /usr/bin/sqv returned an error code (1), error message is: Verifying signature:            Message has been manipulated
+W: Failed to fetch file:${APTARCHIVE}/dists/unstable/Release.gpg  Sub-process /usr/bin/sqv returned an error code (1), error message is: Verifying signature:            Message has been manipulated
+W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq
+    else
+        testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable Release: The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>
 W: Failed to fetch file:${APTARCHIVE}/dists/unstable/Release.gpg  The following signatures were invalid: BADSIG 5A90D141DBAC8DAE Joe Sixpack (APT Testcases Dummy) <joe@example.org>
 W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq
+    fi
 
     testfailure grep 'evil' rootdir/var/lib/apt/lists/*Release
     testfileequal lists.before "$(listcurrentlistsdirectory)"
diff --git a/test/integration/test-apt-update-repeated-ims-hit b/test/integration/test-apt-update-repeated-ims-hit
index 74d46b31b..43871a31f 100755
--- a/test/integration/test-apt-update-repeated-ims-hit
+++ b/test/integration/test-apt-update-repeated-ims-hit
@@ -40,7 +40,11 @@ rm -f rootdir/etc/apt/trusted.gpg.d/*
 sed -i -e 's#^deb #deb [trusted=yes] #' rootdir/etc/apt/sources.list.d/*
 
 APTARCHIVE="$(readlink -f ./aptarchive)"
+if test -e /usr/bin/sqv; then
+GPGERROR="W: GPG error: file:$APTARCHIVE  Release: The signatures couldn't be verified because no keyring is specified"
+else
 GPGERROR="W: GPG error: file:$APTARCHIVE  Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5A90D141DBAC8DAE"
+fi
 
 msgmsg 'Running update again does not change result' '0'
 testwarningmsg "$GPGERROR" apt update
diff --git a/test/integration/test-apt-update-rollback b/test/integration/test-apt-update-rollback
index 8235968bb..68505f6ba 100755
--- a/test/integration/test-apt-update-rollback
+++ b/test/integration/test-apt-update-rollback
@@ -156,9 +156,16 @@ test_inrelease_to_unauth_inrelease() {
 
     signreleasefiles 'Marvin Paranoid'
 
-    testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E8525D47528144E2
+    if test -e /usr/bin/sqv; then
+        # FIXME: Do not assert sqv output
+        testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable InRelease: Sub-process /usr/bin/sqv returned an error code (1), error message is: Missing key DE66AECA9151AFA1877EC31DE8525D47528144E2, which is needed to verify signature.
+W: Failed to fetch file:$APTARCHIVE/dists/unstable/InRelease  Sub-process /usr/bin/sqv returned an error code (1), error message is: Missing key DE66AECA9151AFA1877EC31DE8525D47528144E2, which is needed to verify signature.
+W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq
+    else
+        testwarningequal "W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:${APTARCHIVE} unstable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E8525D47528144E2
 W: Failed to fetch file:$APTARCHIVE/dists/unstable/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E8525D47528144E2
 W: Some index files failed to download. They have been ignored, or old ones used instead." aptget update -qq
+    fi
 
     testfileequal lists.before "$(listcurrentlistsdirectory)"
     testnotempty find "${ROOTDIR}/var/lib/apt/lists" -name '*_InRelease'
diff --git a/test/integration/test-releasefile-verification b/test/integration/test-releasefile-verification
index 1392a05d1..00c72d7d9 100755
--- a/test/integration/test-releasefile-verification
+++ b/test/integration/test-releasefile-verification
@@ -97,13 +97,20 @@ echo -n 'apt' > aptarchive/apt.deb
 PKGFILE="${TESTDIR}/$(echo "$(basename "$0")" | sed 's#^test-#Packages-#')"
 
 updatewithwarnings() {
-	testwarning aptget update -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1
+	testwarning aptget update -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1
 	testsuccess grep -E "$1" rootdir/tmp/testwarning.output
 }
 
 foreachgpg() {
     rm -f rootdir/etc/apt/apt.conf.d/00gpgvcmd
-	"$@"
+	local sqv="true"
+	if [ "$1" = "--no-sqv" ]; then
+		local sqv=
+		shift
+	fi
+	if [ "$sqv" ]; then
+		"$@"
+	fi
 	for GPGV in "gpgv-sq" "gpgv-g10code"; do
 		msgmsg "Forcing $GPGV to be used"
 		echo "APT::Key::GPGVCommand \"$GPGV\";" > "rootdir/etc/apt/apt.conf.d/00gpgvcmd"
@@ -147,7 +154,7 @@ runtest() {
 	rm -rf rootdir/var/lib/apt/lists
 	cp keys/rexexpired.pub rootdir/etc/apt/trusted.gpg.d/rexexpired.gpg
 	signreleasefiles 'Rex Expired'
-	updatewithwarnings '^W: .* EXPKEYSIG'
+	updatewithwarnings '^W: .* (EXPKEYSIG|Expired)'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	failaptold
@@ -157,7 +164,7 @@ runtest() {
 	prepare "${PKGFILE}"
 	rm -rf rootdir/var/lib/apt/lists
 	signreleasefiles 'Joe Sixpack,Marvin Paranoid'
-	successfulaptgetupdate 'NO_PUBKEY'
+	successfulaptgetupdate 'NO_PUBKEY\|GOODSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	installaptold
@@ -167,7 +174,7 @@ runtest() {
 	rm -rf rootdir/var/lib/apt/lists
 	signreleasefiles 'Joe Sixpack,Rex Expired'
 	cp keys/rexexpired.pub rootdir/etc/apt/trusted.gpg.d/rexexpired.gpg
-	successfulaptgetupdate 'EXPKEYSIG'
+	successfulaptgetupdate 'EXPKEYSIG\|GOODSIG 34A8E9D18DB320F367E8EAA05A90D141DBAC8DAE'
 	rm -f rootdir/etc/apt/trusted.gpg.d/rexexpired.gpg
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
@@ -177,7 +184,7 @@ runtest() {
 	prepare "${PKGFILE}"
 	rm -rf rootdir/var/lib/apt/lists
 	signreleasefiles 'Marvin Paranoid'
-	updatewithwarnings '^W: .* NO_PUBKEY'
+	updatewithwarnings '^W: .* (NO_PUBKEY|Missing key)'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	failaptold
@@ -202,7 +209,7 @@ runtest() {
 	msgmsg 'Good warm archive signed by' 'Marvin Paranoid'
 	prepare "${PKGFILE}-new"
 	signreleasefiles 'Marvin Paranoid'
-	updatewithwarnings '^W: .* NO_PUBKEY'
+	updatewithwarnings '^W: .* (NO_PUBKEY|Missing key)'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	installaptold
@@ -212,7 +219,7 @@ runtest() {
     # Use a colon here to test weird filenames too
 	cp keys/rexexpired.pub rootdir/etc/apt/trusted.gpg.d/rex:expired.gpg
 	signreleasefiles 'Rex Expired'
-	updatewithwarnings '^W: .* EXPKEYSIG'
+	updatewithwarnings '^W: .* (EXPKEYSIG|Expired)'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	installaptold
@@ -230,7 +237,7 @@ runtest() {
 	rm -rf rootdir/var/lib/apt/lists
 	local MARVIN="$(readlink -f keys/marvinparanoid.pub)"
 	sed -i "s#^\(deb\(-src\)\?\) #\1 [signed-by=$MARVIN] #" rootdir/etc/apt/sources.list.d/*
-	updatewithwarnings '^W: .* NO_PUBKEY'
+	updatewithwarnings '^W: .* (NO_PUBKEY|Missing key)'
 
 	msgmsg 'Cold archive signed by good keyring' 'Marvin Paranoid'
 	prepare "${PKGFILE}"
@@ -265,7 +272,7 @@ runtest() {
 	rm -rf rootdir/var/lib/apt/lists
 	signreleasefiles 'Joe Sixpack'
 	sed -i "s#^\(deb\(-src\)\?\) #\1 [signed-by=$MARVIN] #" rootdir/etc/apt/sources.list.d/*
-	updatewithwarnings '^W: .* be verified because the public key is not available: .*'
+	updatewithwarnings '^W: .* (be verified because the public key is not available: .*|No good signature from required signer)'
 
 	msgmsg 'Cold archive signed by good keyid' 'Marvin Paranoid'
 	rm -rf rootdir/var/lib/apt/lists
@@ -279,7 +286,7 @@ runtest() {
 	msgmsg 'Cold archive signed by good keyid' 'Marvin Paranoid,Joe Sixpack'
 	rm -rf rootdir/var/lib/apt/lists
 	signreleasefiles 'Marvin Paranoid,Joe Sixpack'
-	successfulaptgetupdate 'NoPubKey: GOODSIG'
+	successfulaptgetupdate 'NoPubKey: GOODSIG\|DE66AECA9151AFA1877EC31DE8525D47528144E2'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	installaptold
@@ -324,7 +331,7 @@ Signed-By: ${SIXPACK}" rootdir/var/lib/apt/lists/*Release
 	sed -i "/^Valid-Until: / a\
 Signed-By: ${MARVIN}" rootdir/var/lib/apt/lists/*Release
 	touch -d 'now - 1 year' rootdir/var/lib/apt/lists/*Release
-	updatewithwarnings 'W: .* public key is not available: GOODSIG'
+	updatewithwarnings 'W: .* (public key is not available: GOODSIG|No good signature from required signer:)'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	installaptold
@@ -373,22 +380,26 @@ Signed-By: ${SEBASTIAN}" rootdir/var/lib/apt/lists/*Release
 	sed -i "/^Valid-Until: / a\
 Signed-By: ${SEBASTIAN}!" rootdir/var/lib/apt/lists/*Release
 	touch -d 'now - 1 year' rootdir/var/lib/apt/lists/*Release
-	updatewithwarnings 'W: .* public key is not available: GOODSIG'
+	updatewithwarnings 'W: .* (public key is not available: GOODSIG|No good signature from required signer:)'
 	testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 	installaptold
 
 	local SUBKEY="4281DEDBD466EAE8C1F4157E5B6896415D44C43E"
+	# This is only supported for gpgv, so require an explicit gpgv command,
+	# otherwise the default verification backend may be sqv.
+	if [ "$GPGV" ]; then
 	msgmsg 'Warm archive with correct exact subkey signing' 'Sebastian Subkey'
 	rm -rf rootdir/var/lib/apt/lists
 	cp -a rootdir/var/lib/apt/lists-bak rootdir/var/lib/apt/lists
-	sed -i "/^Valid-Until: / a\
+		sed -i "/^Valid-Until: / a\
 Signed-By: ${SUBKEY}!" rootdir/var/lib/apt/lists/*Release
-	touch -d 'now - 1 year' rootdir/var/lib/apt/lists/*Release
-	successfulaptgetupdate
-	testsuccessequal "$(cat "${PKGFILE}-new")
+		touch -d 'now - 1 year' rootdir/var/lib/apt/lists/*Release
+		successfulaptgetupdate
+		testsuccessequal "$(cat "${PKGFILE}-new")
 " aptcache show apt
-	installaptnew
+		installaptnew
+	fi
 	rm -f rootdir/etc/apt/trusted.gpg.d/sebastiansubkey.gpg
 }
 
@@ -419,16 +430,6 @@ runtest2() {
 	find aptarchive -name Release -exec sh -c "echo Hello > {}.gpg" \;
 	testfailuremsg "E: GPG error: http://localhost:${APTHTTPPORT}  Release: Signed file isn't valid, got 'NODATA' (does the network require authentication?)" aptget update
 
-	msgmsg 'Cold archive signed by' 'Empty inline'
-	rm -rf rootdir/var/lib/apt/lists
-	find aptarchive -name Release -exec sh -c '( echo -----BEGIN PGP SIGNED MESSAGE-----; echo Hash: SHA512; echo; cat {} ; echo; echo -----BEGIN PGP SIGNATURE-----; echo ; echo -----END PGP SIGNATURE----- ) > $(dirname {})/In$(basename {})' \;
-	testfailuremsg "E: GPG error: http://localhost:${APTHTTPPORT}  InRelease: Signed file isn't valid, got 'NODATA' (does the network require authentication?)" aptget update
-
-	msgmsg 'Cold archive signed by' 'Bad inline'
-	rm -rf rootdir/var/lib/apt/lists
-	find aptarchive -name Release -exec sh -c '( echo -----BEGIN PGP SIGNED MESSAGE-----; echo Hash: SHA512; echo; cat {} ; echo; echo -----BEGIN PGP SIGNATURE-----; echo ; echo SGVsbG8K; echo =nFa9; echo -----END PGP SIGNATURE----- ) > $(dirname {})/In$(basename {})' \;
-	testfailuremsg "E: GPG error: http://localhost:${APTHTTPPORT}  InRelease: Signed file isn't valid, got 'NODATA' (does the network require authentication?)" aptget update
-
 	find aptarchive/ \( -name InRelease -o -name Release.gpg \) -delete
 
 	# Unsigned archive from the beginning must also be detected.
@@ -463,7 +464,7 @@ EOF
 export APT_TESTS_DIGEST_ALGO='SHA512'
 
 successfulaptgetupdate() {
-	testsuccess aptget update -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1
+	testsuccess aptget update -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1
 	if [ -n "$1" ]; then
 		cp rootdir/tmp/testsuccess.output aptupdate.output
 		testsuccess grep "$1" aptupdate.output
@@ -472,13 +473,13 @@ successfulaptgetupdate() {
 foreachgpg runtest3 'Trusted'
 
 successfulaptgetupdate() {
-	testwarning aptget update -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1
+	testwarning aptget update -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1
 	if [ -n "$1" ]; then
 		testsuccess grep "$1" rootdir/tmp/testwarning.output
 	fi
 	testsuccess grep 'uses weak algorithm' rootdir/tmp/testwarning.output
 }
-foreachgpg runtest3 'Weak'
+foreachgpg --no-sqv runtest3 'Weak'
 
 msgmsg "Running test with apt-untrusted digest"
 echo "APT::Hashes::$APT_TESTS_DIGEST_ALGO::Untrusted \"yes\";" > rootdir/etc/apt/apt.conf.d/truststate
@@ -489,14 +490,14 @@ runfailure() {
 		prepare "${PKGFILE}"
 		rm -rf rootdir/var/lib/apt/lists
 		signreleasefiles 'Joe Sixpack'
-		testfailure aptget update --no-allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1
-		testsuccess grep 'The following signatures were invalid' rootdir/tmp/testfailure.output
+		testfailure aptget update --no-allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1
+		testsuccess grep 'The following signatures were invalid\|MD5 is not considered secure' rootdir/tmp/testfailure.output
 		testnopackage 'apt'
-		testwarning aptget update --allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1
+		testwarning aptget update --allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1
 		failaptold
 		rm -rf rootdir/var/lib/apt/lists
 		sed -i 's#^deb\(-src\)\? #deb\1 [allow-insecure=yes] #' rootdir/etc/apt/sources.list.d/*
-		testwarning aptget update --no-allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1
+		testwarning aptget update --no-allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1
 		failaptold
 		sed -i 's#^deb\(-src\)\? \[allow-insecure=yes\] #deb\1 #' rootdir/etc/apt/sources.list.d/*
 
@@ -504,13 +505,13 @@ runfailure() {
 		prepare "${PKGFILE}"
 		rm -rf rootdir/var/lib/apt/lists
 		signreleasefiles 'Marvin Paranoid'
-		testfailure aptget update --no-allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1
+		testfailure aptget update --no-allow-insecure-repositories -o Debug::pkgAcquire::Worker=1 -o Debug::Acquire::gpgv=1 -o Debug::Acquire::sqv=1
 		testnopackage 'apt'
-		updatewithwarnings '^W: .* NO_PUBKEY'
+		updatewithwarnings '^W: .* (NO_PUBKEY|Missing key)'
 		testsuccessequal "$(cat "${PKGFILE}")
 " aptcache show apt
 		failaptold
 		export APT_DONT_SIGN='Release.gpg'
 	done
 }
-foreachgpg runfailure
+foreachgpg --no-sqv runfailure
diff --git a/test/integration/test-signed-by-option b/test/integration/test-signed-by-option
index 8e1e9a8c2..e6a3fbb86 100755
--- a/test/integration/test-signed-by-option
+++ b/test/integration/test-signed-by-option
@@ -66,7 +66,7 @@ xSigned-By:
     -----END PGP PUBLIC KEY BLOCK-----
 EOF
 testfailure apt update  -o Debug::Acquire::gpgv=1
-testsuccess grep "NO_PUBKEY 5A90D141DBAC8DAE" rootdir/tmp/testfailure.output
+testsuccess grep -E "(NO_PUBKEY 5A90D141DBAC8DAE|no keyring is specified)" rootdir/tmp/testfailure.output
 sed -i s/^xSigned-By/Signed-By/ rootdir/etc/apt/sources.list.d/deb822.sources
 testsuccess apt update  -o Debug::Acquire::gpgv=1
 # make sure we did not leave leftover files (LP: #1995247)