implement Signed-By without using gpg for verification

[apt.git] / methods / gpgv.cc

diff --git a/methods/gpgv.cc b/methods/gpgv.cc
index 25ba0d06350e433701b85add7c392201c36b65c7..d88a0678927fec71cd7e48dd0106c0bd5a315f83 100644 (file)
--- a/methods/gpgv.cc
+++ b/methods/gpgv.cc
@@ -1,19 +1,24 @@
 #include <config.h>
 
 #include <config.h>
 

-#include <apt-pkg/error.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 <apt-pkg/indexcopy.h>
-#include <apt-pkg/configuration.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 <unistd.h>
+
+#include <algorithm>

 #include <iostream>
 #include <iostream>

-#include <sstream>
+#include <string>

 #include <vector>
 
 #include <apti18n.h>
 #include <vector>
 
 #include <apti18n.h>


@@ -34,34 +39,44 @@ class GPGVMethod : public pkgAcqMethod
 {
    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> &NoPubKeySigners);
    
    protected:
                                 vector<string> &BadSigners,
                                 vector<string> &WorthlessSigners,
                                vector<string> &NoPubKeySigners);
    
    protected:

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

    public:
    
    GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
 };
 
    public:
    
    GPGVMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
 };
 

+bool GPGVMethod::Configuration(string Message)
+{
+   if (pkgAcqMethod::Configuration(Message) == false)
+      return false;
+
+   DropPrivsOrDie();
+
+   return true;
+}
+

 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> &NoPubKeySigners)
 {
    bool const Debug = _config->FindB("Debug::Acquire::gpgv", false);
                                         vector<string> &GoodSigners,
                                         vector<string> &BadSigners,
                                         vector<string> &WorthlessSigners,
                                         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;
 
    int fd[2];
 
    if (Debug == true)
       std::clog << "inside VerifyGetSigners" << std::endl;
 
    int fd[2];

+   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";


@@ -70,51 +85,19 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
    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)

-   {
-      _error->PushToStack();
-      bool const success = SigVerify::RunGPGV(outfile, file, 3, fd);
-      if (success == false)
-      {
-        string errmsg;
-        _error->PopMessage(errmsg);
-        _error->RevertToStack();
-        return errmsg;
-      }
-      _error->RevertToStack();
-      exit(111);
-   }
+      ExecGPGV(outfile, file, 3, fd, (keyIsID ? "" : key));

    close(fd[1]);
 
    FILE *pipein = fdopen(fd[0], "r");
 
    close(fd[1]);
 
    FILE *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;
+   // Loop over the output of apt-key (which really is gnupg), and check the signatures.
+   std::vector<std::string> ValidSigners;
+   size_t buffersize = 0;
+   char *buffer = NULL;

    while (1)
    {
    while (1)
    {

-      int c;
-
-      // Read a line.  Sigh.
-      while ((c = getc(pipein)) != EOF && c != '\n')
-      {
-        if (bufferoff == buffersize)
-        {
-           char* newBuffer = (char *) realloc(buffer, buffersize *= 2);
-           if (newBuffer == NULL)
-           {
-              free(buffer);
-              return "Couldn't allocate a buffer big enough for reading";
-           }
-           buffer = newBuffer;
-        }
-         *(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;
 


@@ -128,32 +111,31 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
             std::clog << "Got BADSIG! " << std::endl;
          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }
             std::clog << "Got BADSIG! " << std::endl;
          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }

-      
-      if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0)
+      else if (strncmp(buffer, GNUPGNOPUBKEY, sizeof(GNUPGNOPUBKEY)-1) == 0)

       {
          if (Debug == true)
             std::clog << "Got NO_PUBKEY " << std::endl;
          NoPubKeySigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }
       {
          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)
+      else 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 (Debug == true)
             std::clog << "Got NODATA! " << std::endl;
          BadSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }

-      if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0)
+      else if (strncmp(buffer, GNUPGKEYEXPIRED, sizeof(GNUPGKEYEXPIRED)-1) == 0)

       {
          if (Debug == true)
             std::clog << "Got KEYEXPIRED! " << std::endl;
          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }
       {
          if (Debug == true)
             std::clog << "Got KEYEXPIRED! " << std::endl;
          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }

-      if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0)
+      else if (strncmp(buffer, GNUPGREVKEYSIG, sizeof(GNUPGREVKEYSIG)-1) == 0)

       {
          if (Debug == true)
             std::clog << "Got REVKEYSIG! " << std::endl;
          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }
       {
          if (Debug == true)
             std::clog << "Got REVKEYSIG! " << std::endl;
          WorthlessSigners.push_back(string(buffer+sizeof(GNUPGPREFIX)));
       }

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

       {
          char *sig = buffer + sizeof(GNUPGPREFIX);
          char *p = sig + sizeof("GOODSIG");
       {
          char *sig = buffer + sizeof(GNUPGPREFIX);
          char *p = sig + sizeof("GOODSIG");


@@ -164,42 +146,92 @@ string GPGVMethod::VerifyGetSigners(const char *file, const char *outfile,
             std::clog << "Got GOODSIG, key ID:" << sig << std::endl;
          GoodSigners.push_back(string(sig));
       }
             std::clog << "Got GOODSIG, key ID:" << sig << std::endl;
          GoodSigners.push_back(string(sig));
       }

+      else if (strncmp(buffer, GNUPGVALIDSIG, sizeof(GNUPGVALIDSIG)-1) == 0)
+      {
+         char *sig = buffer + sizeof(GNUPGVALIDSIG);
+         char *p = sig;
+         while (*p && isxdigit(*p))
+            p++;
+         *p = 0;
+         if (Debug == true)
+            std::clog << "Got VALIDSIG, key ID: " << sig << std::endl;
+         ValidSigners.push_back(string(sig));
+      }

    }
    fclose(pipein);
    }
    fclose(pipein);

+   free(buffer);
+
+   // 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;
+      std::vector<std::string>::iterator const foundItr = std::find(ValidSigners.begin(), ValidSigners.end(), key);
+      bool const found = (foundItr != ValidSigners.end());
+      std::copy(GoodSigners.begin(), GoodSigners.end(), std::back_insert_iterator<std::vector<std::string> >(NoPubKeySigners));
+      if (found)
+      {
+        // 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 " + key.substr(24, 16);
+        bool const foundGood = std::find(GoodSigners.begin(), GoodSigners.end(), goodlongkeyid) != GoodSigners.end();
+        if (Debug == true)
+           std::clog << "Key " << key << " is valid sig, is " << goodlongkeyid << " also a good one? " << (foundGood ? "yes" : "no") << std::endl;
+        GoodSigners.clear();
+        if (foundGood)
+        {
+           GoodSigners.push_back(goodlongkeyid);
+           NoPubKeySigners.erase(std::remove(NoPubKeySigners.begin(), NoPubKeySigners.end(), goodlongkeyid), NoPubKeySigners.end());
+        }
+      }
+      else
+        GoodSigners.clear();
+   }

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

-      if (GoodSigners.empty())
-         return _("Internal error: Good signature, but could not determine key fingerprint?!");
+      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 "";
    }
    else if (WEXITSTATUS(status) == 1)

-   {

       return _("At least one invalid signature was encountered.");
       return _("At least one invalid signature was encountered.");

-   }

    else if (WEXITSTATUS(status) == 111)
    else if (WEXITSTATUS(status) == 111)

+      return _("Could not execute 'apt-key' to verify signature (is gnupg installed?)");
+   else if (WEXITSTATUS(status) == 112)

    {
    {

-      ioprintf(ret, _("Could not execute 'gpgv' to verify signature (is gpgv installed?)"));
-      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, _("Clearsigned file isn't valid, got '%s' (does the network require authentication?)"), "NODATA");
+      return errmsg;

    }
    else
    }
    else

-   {
-      return _("Unknown error executing gpgv");
-   }
+      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> GoodSigners;
    vector<string> BadSigners;
    // a worthless signature is a expired or revoked one


@@ -210,8 +242,8 @@ bool GPGVMethod::Fetch(FetchItem *Itm)
    Res.Filename = Itm->DestFile;
    URIStart(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,
                                  NoPubKeySigners);
    if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty())
                                  GoodSigners, BadSigners, WorthlessSigners,
                                  NoPubKeySigners);
    if (GoodSigners.empty() || !BadSigners.empty() || !NoPubKeySigners.empty())


@@ -262,7 +294,7 @@ bool GPGVMethod::Fetch(FetchItem *Itm)
 
    if (_config->FindB("Debug::Acquire::gpgv", false))
    {
 
    if (_config->FindB("Debug::Acquire::gpgv", false))
    {

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

    }
 
    return true;
    }
 
    return true;


@@ -272,7 +304,7 @@ 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();