remove duplicated 'the' from guides doc-base abstract

[apt.git] / methods / gpgv.cc

diff --git a/methods/gpgv.cc b/methods/gpgv.cc
index c58e6cc45781253b1d53b4b2e63007e66e6bfd07..dd395d6598c8fb34d3327b0307810e9ac68b7c57 100644 (file)
--- a/methods/gpgv.cc
+++ b/methods/gpgv.cc
@@ -1,178 +1,183 @@
-#include <apt-pkg/error.h>
+#include <config.h>
+

 #include <apt-pkg/acquire-method.h>
 #include <apt-pkg/acquire-method.h>

+#include <apt-pkg/configuration.h>
+#include <apt-pkg/error.h>
+#include <apt-pkg/gpgv.h>

 #include <apt-pkg/strutl.h>
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/fileutl.h>

-#include <apti18n.h>
+#include "aptmethod.h"

 
 

-#include <utime.h>
-#include <stdio.h>
-#include <fcntl.h>
+#include <ctype.h>

 #include <errno.h>
 #include <errno.h>

+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>

 #include <sys/wait.h>
 #include <sys/wait.h>

-#include <iostream>
+#include <unistd.h>
+
+#include <array>
+#include <algorithm>

 #include <sstream>
 #include <sstream>

+#include <iterator>
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include <apti18n.h>
+
+using std::string;
+using std::vector;

 
 #define GNUPGPREFIX "[GNUPG:]"
 #define GNUPGBADSIG "[GNUPG:] BADSIG"
 
 #define GNUPGPREFIX "[GNUPG:]"
 #define GNUPGBADSIG "[GNUPG:] BADSIG"

+#define GNUPGERRSIG "[GNUPG:] ERRSIG"

 #define GNUPGNOPUBKEY "[GNUPG:] NO_PUBKEY"
 #define GNUPGVALIDSIG "[GNUPG:] VALIDSIG"
 #define GNUPGGOODSIG "[GNUPG:] GOODSIG"
 #define GNUPGNOPUBKEY "[GNUPG:] NO_PUBKEY"
 #define GNUPGVALIDSIG "[GNUPG:] VALIDSIG"
 #define GNUPGGOODSIG "[GNUPG:] GOODSIG"

-#define GNUPGKEYEXPIRED "[GNUPG:] KEYEXPIRED"
+#define GNUPGEXPKEYSIG "[GNUPG:] EXPKEYSIG"
+#define GNUPGEXPSIG "[GNUPG:] EXPSIG"

 #define GNUPGREVKEYSIG "[GNUPG:] REVKEYSIG"
 #define GNUPGNODATA "[GNUPG:] NODATA"
 
 #define GNUPGREVKEYSIG "[GNUPG:] REVKEYSIG"
 #define GNUPGNODATA "[GNUPG:] NODATA"
 

-class GPGVMethod : public pkgAcqMethod
+struct Digest {
+   enum class State {
+      Untrusted,
+      Weak,
+      Trusted,
+   } state;
+   char name[32];
+
+   State getState() const {
+      std::string optionUntrusted;
+      std::string optionWeak;
+      strprintf(optionUntrusted, "APT::Hashes::%s::Untrusted", name);
+      strprintf(optionWeak, "APT::Hashes::%s::Weak", name);
+      if (_config->FindB(optionUntrusted, state == State::Untrusted) == true)
+        return State::Untrusted;
+      if (_config->FindB(optionWeak, state == State::Weak) == true)
+        return State::Weak;
+
+      return state;
+   }
+};
+
+static constexpr Digest Digests[] = {
+   {Digest::State::Untrusted, "Invalid digest"},
+   {Digest::State::Untrusted, "MD5"},
+   {Digest::State::Weak, "SHA1"},
+   {Digest::State::Weak, "RIPE-MD/160"},
+   {Digest::State::Trusted, "Reserved digest"},
+   {Digest::State::Trusted, "Reserved digest"},
+   {Digest::State::Trusted, "Reserved digest"},
+   {Digest::State::Trusted, "Reserved digest"},
+   {Digest::State::Trusted, "SHA256"},
+   {Digest::State::Trusted, "SHA384"},
+   {Digest::State::Trusted, "SHA512"},
+   {Digest::State::Trusted, "SHA224"},
+};
+
+static Digest FindDigest(std::string const & Digest)
+{
+   int id = atoi(Digest.c_str());
+   if (id >= 0 && static_cast<unsigned>(id) < _count(Digests)) {
+      return Digests[id];
+   } else {
+      return Digests[0];
+   }
+}
+
+struct Signer {
+   std::string key;
+   std::string note;
+};
+static bool IsTheSameKey(std::string const &validsig, std::string const &goodsig) {
+   // VALIDSIG reports a keyid (40 = 24 + 16), GOODSIG is a longid (16) only
+   return validsig.compare(24, 16, goodsig, strlen("GOODSIG "), 16) == 0;
+}
+
+class GPGVMethod : public aptMethod

 {
    private:
    string VerifyGetSigners(const char *file, const char *outfile,
 {
    private:
    string VerifyGetSigners(const char *file, const char *outfile,

-                               vector<string> &GoodSigners, 
+                               std::string const &key,
+                               vector<string> &GoodSigners,

                                 vector<string> &BadSigners,
                                 vector<string> &WorthlessSigners,
                                 vector<string> &BadSigners,
                                 vector<string> &WorthlessSigners,

+                                vector<Signer> &SoonWorthlessSigners,

                                vector<string> &NoPubKeySigners);
                                vector<string> &NoPubKeySigners);

-   

    protected:
    protected:

-   virtual bool Fetch(FetchItem *Itm);
-   
+   virtual bool URIAcquire(std::string const &Message, FetchItem *Itm) APT_OVERRIDE;

    public:
    public:

-   
-   GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
+   GPGVMethod() : aptMethod("gpgv","1.0",SingleInstance | SendConfig) {};

 };
 };

-
+static void PushEntryWithKeyID(std::vector<std::string> &Signers, char * const buffer, bool const Debug)
+{
+   char * const msg = buffer + sizeof(GNUPGPREFIX);
+   char *p = msg;
+   // skip the message
+   while (*p && !isspace(*p))
+      ++p;
+   // skip the seperator whitespace
+   ++p;
+   // skip the hexdigit fingerprint
+   while (*p && isxdigit(*p))
+      ++p;
+   // cut the rest from the message
+   *p = '\0';
+   if (Debug == true)
+      std::clog << "Got " << msg << " !" << std::endl;
+   Signers.push_back(msg);
+}
+static void PushEntryWithUID(std::vector<std::string> &Signers, char * const buffer, bool const Debug)
+{
+   std::string msg = buffer + sizeof(GNUPGPREFIX);
+   auto const nuke = msg.find_last_not_of("\n\t\r");
+   if (nuke != std::string::npos)
+      msg.erase(nuke + 1);
+   if (Debug == true)
+      std::clog << "Got " << msg << " !" << std::endl;
+   Signers.push_back(msg);
+}

 string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
 string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,

+                                        std::string const &key,

                                         vector<string> &GoodSigners,
                                         vector<string> &BadSigners,
                                         vector<string> &WorthlessSigners,
                                         vector<string> &GoodSigners,
                                         vector<string> &BadSigners,
                                         vector<string> &WorthlessSigners,

+                                        vector<Signer> &SoonWorthlessSigners,

                                         vector<string> &NoPubKeySigners)
 {
    bool const Debug = _config->FindB("Debug::Acquire::gpgv", false);
                                         vector<string> &NoPubKeySigners)
 {
    bool const Debug = _config->FindB("Debug::Acquire::gpgv", false);

-   // setup a (empty) stringstream for formating the return value
-   std::stringstream ret;
-   ret.str("");

 
    if (Debug == true)
       std::clog << "inside VerifyGetSigners" << std::endl;
 
 
    if (Debug == true)
       std::clog << "inside VerifyGetSigners" << std::endl;
 

-   pid_t pid;

    int fd[2];
    int fd[2];

-   FILE *pipein;
-   int status;
-   string const gpgvpath = _config->Find("Dir::Bin::gpg", "/usr/bin/gpgv");
-   // FIXME: remove support for deprecated APT::GPGV setting
-   string const trustedFile = _config->FindFile("Dir::Etc::Trusted",
-                       _config->Find("APT::GPGV::TrustedKeyring", "/etc/apt/trusted.gpg").c_str());
-   string const trustedPath = _config->FindDir("Dir::Etc::TrustedParts", "/etc/apt/trusted.gpg.d");
-   if (Debug == true)
-   {
-      std::clog << "gpgv path: " << gpgvpath << std::endl;
-      std::clog << "Keyring file: " << trustedFile << std::endl;
-      std::clog << "Keyring path: " << trustedPath << std::endl;
-   }
-
-   vector<string> keyrings = GetListOfFilesInDir(trustedPath, "gpg", false);
-   if (FileExists(trustedFile) == true)
-      keyrings.push_back(trustedFile);
-
-   if (keyrings.empty() == true)
-   {
-      // TRANSLATOR: %s is the trusted keyring parts directory
-      ioprintf(ret, _("No keyring installed in %s."), trustedPath.c_str());
-      return ret.str();
-   }
+   bool const keyIsID = (key.empty() == false && key[0] != '/');

 
    if (pipe(fd) < 0)
       return "Couldn't create pipe";
 
 
    if (pipe(fd) < 0)
       return "Couldn't create pipe";
 

-   pid = fork();
+   pid_t pid = fork();

    if (pid < 0)
       return string("Couldn't spawn new process") + strerror(errno);
    else if (pid == 0)
    if (pid < 0)
       return string("Couldn't spawn new process") + strerror(errno);
    else if (pid == 0)

-   {
-      const char *Args[400];
-      unsigned int i = 0;
-
-      Args[i++] = gpgvpath.c_str();
-      Args[i++] = "--status-fd";
-      Args[i++] = "3";
-      Args[i++] = "--ignore-time-conflict";
-      for (vector<string>::const_iterator K = keyrings.begin();
-          K != keyrings.end(); ++K)
-      {
-        Args[i++] = "--keyring";
-        Args[i++] = K->c_str();
-        // check overflow (minus a bit of extra space at the end)
-        if(i >= sizeof(Args)/sizeof(char*)-5) {
-           std::clog << _("E: Too many keyrings should be passed to gpgv. Exiting.") << std::endl;
-           exit(111);
-        }
-      }
-
-      Configuration::Item const *Opts;
-      Opts = _config->Tree("Acquire::gpgv::Options");
-      if (Opts != 0)
-      {
-         Opts = Opts->Child;
-        for (; Opts != 0; Opts = Opts->Next)
-         {
-            if (Opts->Value.empty() == true)
-               continue;
-            Args[i++] = Opts->Value.c_str();
-           // check overflow (minus a bit of extra space at the end)
-           if(i >= sizeof(Args)/sizeof(char*)-5) { 
-              std::clog << _("E: Argument list from Acquire::gpgv::Options too long. Exiting.") << std::endl;
-              exit(111);
-           }
-         }
-      }
-      Args[i++] = file;
-      Args[i++] = outfile;
-      Args[i++] = NULL;
-
-      if (Debug == true)
-      {
-         std::clog << "Preparing to exec: " << gpgvpath;
-        for(unsigned int j=0;Args[j] != NULL; j++)
-           std::clog << " " << Args[j];
-        std::clog << std::endl;
-      }
-      int const nullfd = open("/dev/null", O_RDONLY);
-      close(fd[0]);
-      // Redirect output to /dev/null; we read from the status fd
-      dup2(nullfd, STDOUT_FILENO); 
-      dup2(nullfd, STDERR_FILENO); 
-      // Redirect the pipe to the status fd (3)
-      dup2(fd[1], 3);
-
-      putenv((char *)"LANG=");
-      putenv((char *)"LC_ALL=");
-      putenv((char *)"LC_MESSAGES=");
-      execvp(gpgvpath.c_str(), (char **)Args);
-             
-      exit(111);
-   }
+      ExecGPGV(outfile, file, 3, fd, (keyIsID ? "" : key));

    close(fd[1]);
 
    close(fd[1]);
 

-   pipein = fdopen(fd[0], "r"); 
-   
-   // Loop over the output of gpgv, and check the signatures.
-   size_t buffersize = 64;
-   char *buffer = (char *) malloc(buffersize);
-   size_t bufferoff = 0;
+   FILE *pipein = fdopen(fd[0], "r");
+
+   // Loop over the output of apt-key (which really is gnupg), and check the signatures.
+   std::vector<std::string> ValidSigners;
+   std::vector<std::string> ErrSigners;
+   size_t buffersize = 0;
+   char *buffer = NULL;
+   bool gotNODATA = false;

    while (1)
    {
    while (1)
    {

-      int c;
-
-      // Read a line.  Sigh.
-      while ((c = getc(pipein)) != EOF && c != '\n')
-      {
-         if (bufferoff == buffersize)
-            buffer = (char *) realloc(buffer, buffersize *= 2);
-         *(buffer+bufferoff) = c;
-         bufferoff++;
-      }
-      if (bufferoff == 0 && c == EOF)
-         break;
-      *(buffer+bufferoff) = '\0';
-      bufferoff = 0;
+      if (getline(&buffer, &buffersize, pipein) == -1)
+        break;

       if (Debug == true)
          std::clog << "Read: " << buffer << std::endl;
 
       if (Debug == true)
          std::clog << "Read: " << buffer << std::endl;
 


@@ -181,96 +186,190 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
       // if we improve the apt method communication stuff later
       // it will be better.
       if (strncmp(buffer, GNUPGBADSIG, sizeof(GNUPGBADSIG)-1) == 0)
       // if we improve the apt method communication stuff later
       // it will be better.
       if (strncmp(buffer, GNUPGBADSIG, sizeof(GNUPGBADSIG)-1) == 0)

+        PushEntryWithUID(BadSigners, buffer, Debug);
+      else if (strncmp(buffer, GNUPGERRSIG, sizeof(GNUPGERRSIG)-1) == 0)
+        PushEntryWithKeyID(ErrSigners, buffer, Debug);
+      else if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0)

       {
       {

-         if (Debug == true)
-            std::clog << "Got BADSIG! " << std::endl;
-         BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
+        PushEntryWithKeyID(NoPubKeySigners, buffer, Debug);
+        ErrSigners.erase(std::remove_if(ErrSigners.begin(), ErrSigners.end(), [&](std::string const &errsig) {
+                 return errsig.compare(strlen("ERRSIG "), 16, buffer, sizeof(GNUPGNOPUBKEY), 16) == 0;  }), ErrSigners.end());

       }
       }

-      
-      if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0)
+      else if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGNODATA)-1) == 0)
+        gotNODATA = true;
+      else if (strncmp(buffer, GNUPGEXPKEYSIG, sizeof(GNUPGEXPKEYSIG)-1) == 0)
+        PushEntryWithUID(WorthlessSigners, buffer, Debug);
+      else if (strncmp(buffer, GNUPGEXPSIG, sizeof(GNUPGEXPSIG)-1) == 0)
+        PushEntryWithUID(WorthlessSigners, buffer, Debug);
+      else if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0)
+        PushEntryWithUID(WorthlessSigners, buffer, Debug);
+      else if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0)
+        PushEntryWithKeyID(GoodSigners, buffer, Debug);
+      else if (strncmp(buffer, GNUPGVALIDSIG, sizeof(GNUPGVALIDSIG)-1) == 0)

       {
       {

-         if (Debug == true)
-            std::clog << "Got NO_PUBKEY " << std::endl;
-         NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
-      }
-      if (strncmp(buffer, GNUPGNODATA, sizeof(GNUPGBADSIG)-1) == 0)
-      {
-         if (Debug == true)
-            std::clog << "Got NODATA! " << std::endl;
-         BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
-      }
-      if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0)
-      {
-         if (Debug == true)
-            std::clog << "Got KEYEXPIRED! " << std::endl;
-         WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
+         std::istringstream iss(buffer + sizeof(GNUPGVALIDSIG));
+         vector<string> tokens{std::istream_iterator<string>{iss},
+                               std::istream_iterator<string>{}};
+         auto const sig = tokens[0];
+         // Reject weak digest algorithms
+         Digest digest = FindDigest(tokens[7]);
+         switch (digest.getState()) {
+         case Digest::State::Weak:
+            // Treat them like an expired key: For that a message about expiry
+            // is emitted, a VALIDSIG, but no GOODSIG.
+            SoonWorthlessSigners.push_back({sig, digest.name});
+           if (Debug == true)
+              std::clog << "Got weak VALIDSIG, key ID: " << sig << std::endl;
+            break;
+         case Digest::State::Untrusted:
+            // Treat them like an expired key: For that a message about expiry
+            // is emitted, a VALIDSIG, but no GOODSIG.
+            WorthlessSigners.push_back(sig);
+            GoodSigners.erase(std::remove_if(GoodSigners.begin(), GoodSigners.end(), [&](std::string const &goodsig) {
+                    return IsTheSameKey(sig, goodsig); }), GoodSigners.end());
+           if (Debug == true)
+              std::clog << "Got untrusted VALIDSIG, key ID: " << sig << std::endl;
+            break;
+
+        case Digest::State::Trusted:
+           if (Debug == true)
+              std::clog << "Got trusted VALIDSIG, key ID: " << sig << std::endl;
+            break;
+         }
+
+         ValidSigners.push_back(sig);

       }
       }

-      if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0)
+   }
+   fclose(pipein);
+   free(buffer);
+   std::move(ErrSigners.begin(), ErrSigners.end(), std::back_inserter(WorthlessSigners));
+
+   // apt-key has a --keyid parameter, but this requires gpg, so we call it without it
+   // and instead check after the fact which keyids where used for verification
+   if (keyIsID == true)
+   {
+      if (Debug == true)
+        std::clog << "GoodSigs needs to be limited to keyid " << key << std::endl;
+      bool foundGood = false;
+      for (auto const &k: VectorizeString(key, ','))

       {
       {

-         if (Debug == true)
-            std::clog << "Got REVKEYSIG! " << std::endl;
-         WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
+        if (std::find(ValidSigners.begin(), ValidSigners.end(), k) == ValidSigners.end())
+           continue;
+        // we look for GOODSIG here as well as an expired sig is a valid sig as well (but not a good one)
+        std::string const goodlongkeyid = "GOODSIG " + k.substr(24, 16);
+        foundGood = std::find(GoodSigners.begin(), GoodSigners.end(), goodlongkeyid) != GoodSigners.end();
+        if (Debug == true)
+           std::clog << "Key " << k << " is valid sig, is " << goodlongkeyid << " also a good one? " << (foundGood ? "yes" : "no") << std::endl;
+        if (foundGood == false)
+           continue;
+        std::copy(GoodSigners.begin(), GoodSigners.end(), std::back_insert_iterator<std::vector<std::string> >(NoPubKeySigners));
+        GoodSigners.clear();
+        GoodSigners.push_back(goodlongkeyid);
+        NoPubKeySigners.erase(std::remove(NoPubKeySigners.begin(), NoPubKeySigners.end(), goodlongkeyid), NoPubKeySigners.end());
+        break;

       }
       }

-      if (strncmp(buffer, GNUPGGOODSIG, sizeof(GNUPGGOODSIG)-1) == 0)
+      if (foundGood == false)

       {
       {

-         char *sig = buffer + sizeof(GNUPGPREFIX);
-         char *p = sig + sizeof("GOODSIG");
-         while (*p && isxdigit(*p)) 
-            p++;
-         *p = 0;
-         if (Debug == true)
-            std::clog << "Got GOODSIG, key ID:" << sig << std::endl;
-         GoodSigners.push_back(string(sig));
+        std::copy(GoodSigners.begin(), GoodSigners.end(), std::back_insert_iterator<std::vector<std::string> >(NoPubKeySigners));
+        GoodSigners.clear();

       }
    }
       }
    }

-   fclose(pipein);

 
 

+   int status;

    waitpid(pid, &status, 0);
    if (Debug == true)
    {
    waitpid(pid, &status, 0);
    if (Debug == true)
    {

-      std::clog << "gpgv exited\n";
+      ioprintf(std::clog, "gpgv exited with status %i\n", WEXITSTATUS(status));

    }
    }

-   
-   if (WEXITSTATUS(status) == 0)
+
+   if (Debug)

    {
    {

-      if (GoodSigners.empty())
-         return _("Internal error: Good signature, but could not determine key fingerprint?!");
-      return "";
+      std::cerr << "Summary:" << std::endl << "  Good: ";
+      std::copy(GoodSigners.begin(), GoodSigners.end(), std::ostream_iterator<std::string>(std::cerr, ", "));
+      std::cerr << std::endl << "  Bad: ";
+      std::copy(BadSigners.begin(), BadSigners.end(), std::ostream_iterator<std::string>(std::cerr, ", "));
+      std::cerr << std::endl << "  Worthless: ";
+      std::copy(WorthlessSigners.begin(), WorthlessSigners.end(), std::ostream_iterator<std::string>(std::cerr, ", "));
+      std::cerr << std::endl << "  SoonWorthless: ";
+      std::for_each(SoonWorthlessSigners.begin(), SoonWorthlessSigners.end(), [](Signer const &sig) { std::cerr << sig.key << ", "; });
+      std::cerr << std::endl << "  NoPubKey: ";
+      std::copy(NoPubKeySigners.begin(), NoPubKeySigners.end(), std::ostream_iterator<std::string>(std::cerr, ", "));
+      std::cerr << std::endl << "  NODATA: " << (gotNODATA ? "yes" : "no") << std::endl;

    }
    }

-   else if (WEXITSTATUS(status) == 1)
+
+   if (WEXITSTATUS(status) == 112)

    {
    {

-      return _("At least one invalid signature was encountered.");
+      // acquire system checks for "NODATA" to generate GPG errors (the others are only warnings)
+      std::string errmsg;
+      //TRANSLATORS: %s is a single techy word like 'NODATA'
+      strprintf(errmsg, _("Clearsigned file isn't valid, got '%s' (does the network require authentication?)"), "NODATA");
+      return errmsg;

    }
    }

-   else if (WEXITSTATUS(status) == 111)
+   else if (gotNODATA)

    {
    {

-      ioprintf(ret, _("Could not execute '%s' to verify signature (is gpgv installed?)"), gpgvpath.c_str());
-      return ret.str();
+      // acquire system checks for "NODATA" to generate GPG errors (the others are only warnings)
+      std::string errmsg;
+      //TRANSLATORS: %s is a single techy word like 'NODATA'
+      strprintf(errmsg, _("Signed file isn't valid, got '%s' (does the network require authentication?)"), "NODATA");
+      return errmsg;

    }
    }

-   else
+   else if (WEXITSTATUS(status) == 0)

    {
    {

-      return _("Unknown error executing gpgv");
+      if (keyIsID)
+      {
+        // gpgv will report success, but we want to enforce a certain keyring
+        // so if we haven't found the key the valid we found is in fact invalid
+        if (GoodSigners.empty())
+           return _("At least one invalid signature was encountered.");
+      }
+      else
+      {
+        if (GoodSigners.empty())
+           return _("Internal error: Good signature, but could not determine key fingerprint?!");
+      }
+      return "";

    }
    }

+   else if (WEXITSTATUS(status) == 1)
+      return _("At least one invalid signature was encountered.");
+   else if (WEXITSTATUS(status) == 111)
+      return _("Could not execute 'apt-key' to verify signature (is gnupg installed?)");
+   else
+      return _("Unknown error executing apt-key");

 }
 
 }
 

-bool GPGVMethod::Fetch(FetchItem *Itm)
+bool GPGVMethod::URIAcquire(std::string const &Message, FetchItem *Itm)

 {
 {

-   URI Get = Itm->Uri;
-   string Path = Get.Host + Get.Path; // To account for relative paths
-   string keyID;
+   URI const Get = Itm->Uri;
+   string const Path = Get.Host + Get.Path; // To account for relative paths
+   std::string const key = LookupTag(Message, "Signed-By");

    vector<string> GoodSigners;
    vector<string> BadSigners;
    // a worthless signature is a expired or revoked one
    vector<string> WorthlessSigners;
    vector<string> GoodSigners;
    vector<string> BadSigners;
    // a worthless signature is a expired or revoked one
    vector<string> WorthlessSigners;

+   vector<Signer> SoonWorthlessSigners;

    vector<string> NoPubKeySigners;
    
    FetchResult Res;
    Res.Filename = Itm->DestFile;
    URIStart(Res);
 
    vector<string> NoPubKeySigners;
    
    FetchResult Res;
    Res.Filename = Itm->DestFile;
    URIStart(Res);
 

-   // Run gpgv on file, extract contents and get the key ID of the signer
-   string msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(),
+   // Run apt-key on file, extract contents and get the key ID of the signer
+   string msg = VerifyGetSigners(Path.c_str(), Itm->DestFile.c_str(), key,

                                  GoodSigners, BadSigners, WorthlessSigners,
                                  GoodSigners, BadSigners, WorthlessSigners,

-                                 NoPubKeySigners);
+                                 SoonWorthlessSigners, NoPubKeySigners);
+
+   // Check if all good signers are soon worthless and warn in that case
+   if (std::all_of(GoodSigners.begin(), GoodSigners.end(), [&](std::string const &good) {
+           return std::any_of(SoonWorthlessSigners.begin(), SoonWorthlessSigners.end(), [&](Signer const &weak) {
+                 return IsTheSameKey(weak.key, good);
+                 });
+           }))
+   {
+      for (auto const & Signer : SoonWorthlessSigners)
+         // TRANSLATORS: The second %s is the reason and is untranslated for repository owners.
+         Warning(_("Signature by key %s uses weak digest algorithm (%s)"), Signer.key.c_str(), Signer.note.c_str());
+   }
+

    if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty())
    {
       string errmsg;
    if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty())
    {
       string errmsg;


@@ -284,21 +383,21 @@ bool GPGVMethod::Fetch(FetchItem *Itm)
          {
             errmsg += _("The following signatures were invalid:\n");
             for (vector<string>::iterator I = BadSigners.begin();
          {
             errmsg += _("The following signatures were invalid:\n");
             for (vector<string>::iterator I = BadSigners.begin();

-                I != BadSigners.end(); I++)
+                I != BadSigners.end(); ++I)

                errmsg += (*I + "\n");
          }
          if (!WorthlessSigners.empty())
          {
             errmsg += _("The following signatures were invalid:\n");
             for (vector<string>::iterator I = WorthlessSigners.begin();
                errmsg += (*I + "\n");
          }
          if (!WorthlessSigners.empty())
          {
             errmsg += _("The following signatures were invalid:\n");
             for (vector<string>::iterator I = WorthlessSigners.begin();

-                I != WorthlessSigners.end(); I++)
+                I != WorthlessSigners.end(); ++I)

                errmsg += (*I + "\n");
          }
          if (!NoPubKeySigners.empty())
          {
              errmsg += _("The following signatures couldn't be verified because the public key is not available:\n");
             for (vector<string>::iterator I = NoPubKeySigners.begin();
                errmsg += (*I + "\n");
          }
          if (!NoPubKeySigners.empty())
          {
              errmsg += _("The following signatures couldn't be verified because the public key is not available:\n");
             for (vector<string>::iterator I = NoPubKeySigners.begin();

-                I != NoPubKeySigners.end(); I++)
+                I != NoPubKeySigners.end(); ++I)

                errmsg += (*I + "\n");
          }
       }
                errmsg += (*I + "\n");
          }
       }


@@ -313,13 +412,13 @@ bool GPGVMethod::Fetch(FetchItem *Itm)
    // structure is too difficult with the method stuff.  We keep it
    // as three separate vectors for future extensibility.
    Res.GPGVOutput = GoodSigners;
    // structure is too difficult with the method stuff.  We keep it
    // as three separate vectors for future extensibility.
    Res.GPGVOutput = GoodSigners;

-   Res.GPGVOutput.insert(Res.GPGVOutput.end(),BadSigners.begin(),BadSigners.end());
-   Res.GPGVOutput.insert(Res.GPGVOutput.end(),NoPubKeySigners.begin(),NoPubKeySigners.end());
+   std::move(BadSigners.begin(), BadSigners.end(), std::back_inserter(Res.GPGVOutput));
+   std::move(NoPubKeySigners.begin(), NoPubKeySigners.end(), std::back_inserter(Res.GPGVOutput));

    URIDone(Res);
 
    if (_config->FindB("Debug::Acquire::gpgv", false))
    {
    URIDone(Res);
 
    if (_config->FindB("Debug::Acquire::gpgv", false))
    {

-      std::clog << "gpgv succeeded\n";
+      std::clog << "apt-key succeeded\n";

    }
 
    return true;
    }
 
    return true;


@@ -329,7 +428,7 @@ bool GPGVMethod::Fetch(FetchItem *Itm)
 int main()
 {
    setlocale(LC_ALL, "");
 int main()
 {
    setlocale(LC_ALL, "");

-   
+

    GPGVMethod Mth;
 
    return Mth.Run();
    GPGVMethod Mth;
 
    return Mth.Run();