Implement rpmkeys --rebuild

This rebuildis the public key storage. If _keyring is set to a new value
and there are keys left in an old store this fails with an error message.

The keys can either be included by using one or more instances of
--include_backend or dropped with --drop_backends.

Keys are stored in the latest format. Keys no longer accepted are
dropped.

Resolves: rpm-software-management#3347

docs/man/rpmkeys.8.md

@@ -27,6 +27,8 @@ The general forms of rpm digital signature commands are
 
 **rpmkeys** {**-e\|\--erase\|-d\|\--delete**} *FINGERPRINT \...*
 
+**rpmkeys** {**\--rebuild**} \[*\--drop_backends*\] \[*--\include_backend_backend BACKEND*\] \[*--\include_backend_backend BACKEND*\]
+
 **rpmkeys** {**-K\|\--checksig**} *PACKAGE\_FILE \...*
 
 The **\--checksig** option checks all the digests and signatures
@@ -64,6 +66,22 @@ Erase the key(s) designated by *FINGERPRINT*. For example:
 
 **rpmkeys** **\--erase 771b18d3d7baa28734333c424344591e1964c5fc**
 
+Rebuild the key storage:
+
+**rpmkeys** **\--rebuild**
+
+Recreate the public key storage. Update to the latest format and drop
+unreadable keys. This will fail if there are public keys in other
+storage backends.
+
+Adding **\--drop_backends** will delete those keys during rebuilding.
+
+Adding **\--include_backend BACKEND** will keep the keys from the given
+backend and add it to the configured one during rebuilding.
+The parameter can be given more than once. Valid values for the backends
+are **rpmdb**, **fs**, **openpgp**. This can be used to convert from
+one key storage to another.
+
 SEE ALSO
 ========
 

include/rpm/rpmts.h

@@ -754,6 +754,8 @@ rpmtsi rpmtsiInit(rpmts ts);
  */
 rpmte rpmtsiNext(rpmtsi tsi, rpmElementTypes types);
 
+rpmRC rpmtsRebuildKeystore(rpmts ts, char ** loadBackends, int flags);
+
 #ifdef __cplusplus
 }
 #endif

lib/keystore.cc

@@ -1,6 +1,8 @@
 #include "system.h"
 
+#include <filesystem>
 #include <string>
+#include <set>
 
 #include <fcntl.h>
 #include <unistd.h>
@@ -18,11 +20,13 @@
 #include <rpm/rpmtypes.h>
 
 #include "rpmts_internal.hh"
+#include "rpmmacro_internal.hh"
 
 #include "debug.h"
 
 using std::string;
 using namespace rpm;
+namespace fs = std::filesystem;
 
 static int makePubkeyHeader(rpmts ts, rpmPubkey key, Header * hdrp);
 
@@ -118,6 +122,42 @@ rpmRC rpm::check_backends(rpmtxn txn, rpmts ts)
     return rc;
 }
 
+rpmRC rebuild_dir(rpmtxn txn, keystore * store, rpmKeyring keys)
+{
+
+    auto macros = rpm::macros();
+    std::string keyringpath = rpm::expand_path({"%{_keyringpath}"});
+    std::string path = rpm::expand_path({rpmtxnRootDir(txn), keyringpath});
+    std::string oldpath = path + ".rpmold/";
+    std::error_code ec = {};
+    rpmRC rc = RPMRC_OK;
+    macros.push("_keyringpath", "", (keyringpath + ".tmp/").c_str(), 0);
+
+    rpmPubkey key = NULL;
+    auto iter = rpmKeyringInitIterator(keys, 0);
+    while ((rc == RPMRC_OK) && (key = rpmKeyringIteratorNext(iter))) {
+	rc = store->import_key(txn, key, 0, 0);
+    }
+    rpmKeyringIteratorFree(iter);
+
+    if (rc != RPMRC_OK)
+	goto exit;
+
+    /* Ignore errors from (re)moving old directory as it might not exist */
+    fs::rename(path, oldpath, ec);
+    fs::rename(path + ".tmp", path, ec);
+    if (ec) {
+	rpmlog(RPMLOG_ERR, _("can't move new key store to %s: %s.\n"), path.c_str(), ec.message().c_str());
+	rc = RPMRC_FAIL;
+    }
+    fs::remove_all(oldpath);
+
+ exit:
+    macros.pop("_keyringpath");
+
+    return rc;
+}
+
 /*****************************************************************************/
 
 rpmRC keystore_fs::load_keys(rpmtxn txn, rpmKeyring keyring)
@@ -171,6 +211,11 @@ rpmRC keystore_fs::import_key(rpmtxn txn, rpmPubkey key, int replace, rpmFlags f
     return rc;
 }
 
+rpmRC keystore_fs::rebuild(rpmtxn txn, rpmKeyring keys)
+{
+    return rebuild_dir(txn, this, keys);
+}
+
 /*****************************************************************************/
 
 static int acquire_write_lock(rpmtxn txn)
@@ -256,6 +301,12 @@ rpmRC keystore_openpgp_cert_d::import_key(rpmtxn txn, rpmPubkey key, int replace
     return rc;
 }
 
+rpmRC keystore_openpgp_cert_d::rebuild(rpmtxn txn, rpmKeyring keys)
+{
+    return rebuild_dir(txn, this, keys);
+}
+
+
 /*****************************************************************************/
 
 rpmRC keystore_rpmdb::load_keys(rpmtxn txn, rpmKeyring keyring)
@@ -357,6 +408,51 @@ rpmRC keystore_rpmdb::import_key(rpmtxn txn, rpmPubkey key, int replace, rpmFlag
     return rc;
 }
 
+rpmRC keystore_rpmdb::rebuild(rpmtxn txn, rpmKeyring keys)
+{
+    rpmRC rc = RPMRC_OK;
+    std::set<unsigned int> packages = {};
+    Header h = NULL;
+    rpmPubkey key = NULL;
+
+    auto iter = rpmKeyringInitIterator(keys, 0);
+    while ((key = rpmKeyringIteratorNext(iter))) {
+	if (makePubkeyHeader(rpmtxnTs(txn), key, &h) != 0) {
+	    rpmlog(RPMLOG_ERR, _("can't create header for key %s\n"),
+		   rpmPubkeyFingerprintAsHex(key));
+	    rc = RPMRC_FAIL;
+	    break;
+	}
+	if ((rc = rpmtsImportHeader(txn, h, 0)) != RPMRC_OK) {
+	    headerFree(h);
+	    rpmlog(RPMLOG_ERR, _("can't add header to rpmdb for key %s\n"),
+		   rpmPubkeyFingerprintAsHex(key));
+	    break;
+	}
+	packages.insert(headerGetInstance(h));
+	headerFree(h);
+    }
+    rpmKeyringIteratorFree(iter);
+
+    if (rc != RPMRC_OK) {
+	return rc;
+    }
+
+    rpmdbMatchIterator mi = rpmtsInitIterator(rpmtxnTs(txn), RPMDBI_NAME, "gpg-pubkey", 0);
+    while ((h = rpmdbNextIterator(mi)) != NULL) {
+	if (!packages.count(headerGetInstance(h))) {
+	    rpmRC rrc = rpmdbRemove(rpmtsGetRdb(rpmtxnTs(txn)), headerGetInstance(h)) ?
+                RPMRC_FAIL : RPMRC_OK;
+	    if (rc != RPMRC_OK) {
+		rpmlog(RPMLOG_WARNING, "can't remove key %s", headerGetString(h, RPMTAG_NEVR));
+		rc = rrc;
+	    }
+	}
+    }
+    rpmdbFreeIterator(mi);
+    return rc;
+}
+
 static void addGpgProvide(Header h, const char *n, const char *v)
 {
     rpmsenseFlags pflags = (RPMSENSE_KEYRING|RPMSENSE_EQUAL);

lib/keystore.hh

@@ -16,6 +16,7 @@ public:
     virtual rpmRC load_keys(rpmtxn txn, rpmKeyring keyring) = 0;
     virtual rpmRC import_key(rpmtxn txn, rpmPubkey key, int replace = 1, rpmFlags flags = 0) = 0;
     virtual rpmRC delete_key(rpmtxn txn, rpmPubkey key) = 0;
+    virtual rpmRC rebuild(rpmtxn txn, rpmKeyring keys) = 0;
 
     virtual ~keystore() = default;
 };
@@ -26,6 +27,7 @@ public:
     virtual rpmRC load_keys(rpmtxn txn, rpmKeyring keyring);
     virtual rpmRC import_key(rpmtxn txn, rpmPubkey key, int replace = 1, rpmFlags flags = 0);
     virtual rpmRC delete_key(rpmtxn txn, rpmPubkey key);
+    virtual rpmRC rebuild(rpmtxn txn, rpmKeyring keys);
 
 private:
     rpmRC delete_key(rpmtxn txn, const std::string & keyid, const std::string & newname = "");
@@ -37,6 +39,7 @@ public:
     virtual rpmRC load_keys(rpmtxn txn, rpmKeyring keyring);
     virtual rpmRC import_key(rpmtxn txn, rpmPubkey key, int replace = 1, rpmFlags flags = 0);
     virtual rpmRC delete_key(rpmtxn txn, rpmPubkey key);
+    virtual rpmRC rebuild(rpmtxn txn, rpmKeyring keys);
 
 private:
     rpmRC delete_key(rpmtxn txn, const std::string & keyid, unsigned int newinstance = 0);
@@ -48,6 +51,7 @@ public:
     virtual rpmRC load_keys(rpmtxn txn, rpmKeyring keyring);
     virtual rpmRC import_key(rpmtxn txn, rpmPubkey key, int replace = 1, rpmFlags flags = 0);
     virtual rpmRC delete_key(rpmtxn txn, rpmPubkey key);
+    virtual rpmRC rebuild(rpmtxn txn, rpmKeyring keys);
 };
 
 }; /* namespace */

lib/rpmts.cc

@@ -9,6 +9,8 @@
 #include <fcntl.h>
 #include <errno.h>
 
+#include <filesystem>
+
 #include <rpm/rpmtypes.h>
 #include <rpm/rpmlib.h>			/* rpmReadPackage etc */
 #include <rpm/rpmmacro.h>
@@ -31,13 +33,15 @@
 #include "rpmts_internal.hh"
 #include "rpmte_internal.hh"
 #include "rpmlog_internal.hh"
+#include "rpmmacro_internal.hh"
 #include "misc.hh"
 #include "rpmtriggers.hh"
 
 #include "debug.h"
 
 using std::string;
 using namespace rpm;
+namespace fs = std::filesystem;
 
 /**
  * Iterator across transaction elements, forward on install, backward on erase.
@@ -396,6 +400,95 @@ rpmRC rpmtxnDeletePubkey(rpmtxn txn, rpmPubkey key)
     return rc;
 }
 
+rpmRC rpmtsRebuildKeystore(rpmts ts,  char ** loadBackends, int flags)
+{
+    rpmRC rc = RPMRC_OK;
+    rpmtxn txn = rpmtxnBegin(ts, RPMTXN_WRITE);
+    rpmVSFlags oflags = rpmtsVSFlags(ts);
+
+    rpmtsOpenDB(ts, O_RDWR);
+
+    /* XXX keyring wont load if sigcheck disabled, force it temporarily */
+    rpmtsSetVSFlags(ts, (oflags & ~RPMVSF_MASK_NOSIGNATURES));
+
+    keystore * ts_keystore = getKeystore(ts);
+    rpmKeyring keyring = rpmKeyringNew();
+
+    keystore_fs ks_fs = {};
+    keystore_rpmdb ks_rpmdb = {};
+    keystore_openpgp_cert_d ks_opengpg = {};
+
+    for (keystore * ks: std::vector<keystore *>{&ks_fs, &ks_rpmdb, &ks_opengpg}) {
+	rpmKeyring kr = rpmKeyringNew();
+	ks->load_keys(txn, kr);
+
+	char ** name = loadBackends;
+	if (name) {
+	    for (;*name; name++) {
+		if (!strcmp(*name, ks->get_name().c_str()))
+		    break;
+
+	    }
+	}
+
+	/* backend not to be included */
+	if (ks->get_name() != ts->keystore->get_name() && (!name || !*name)) {
+	    if (!rpmKeyringIsEmpty(kr) && !flags) {
+		rpmlog(RPMLOG_ERR, _("public key backend %s is not empty\n"),
+		       ks->get_name().c_str());
+		rpmKeyringFree(kr);
+		rc = RPMRC_FAIL;
+		goto exit;
+	    }
+	    rpmKeyringFree(kr);
+	    continue;
+	}
+
+	rpmKeyringIterator iter = rpmKeyringInitIterator(kr, 0);
+	rpmPubkey key = NULL;
+	while ((key = rpmKeyringIteratorNext(iter)) != NULL) {
+	    const unsigned char * pkt = NULL;
+	    size_t pktlen = 0;
+	    char *lints = NULL;
+
+	    rpmPubkeyRawData(key, &pkt, &pktlen);
+	    int lrc = pgpPubKeyLint(pkt, pktlen, &lints) ;
+	    if (lints) {
+		if (lrc != RPMRC_OK)
+		    rpmlog(RPMLOG_WARNING, "dropping public key %s:\n", rpmPubkeyFingerprintAsHex(key));
+		rpmlog(RPMLOG_WARNING, "%s\n", lints);
+		free(lints);
+		if (lrc != RPMRC_OK)
+		    continue;
+	    }
+	    rpmKeyringModify(keyring, key, RPMKEYRING_MERGE);
+	}
+	rpmKeyringIteratorFree(iter);
+	rpmKeyringFree(kr);
+    }
+
+    rc = ts_keystore->rebuild(txn, keyring);
+
+    if (dynamic_cast<keystore_rpmdb*>(ts_keystore)) {
+	fs::remove_all(rpm::expand_path({rpmtxnRootDir(txn),
+		    "%{_keyringpath}"}));
+    } else {
+	/* remove all gpg-pubkey packages */
+	rpmKeyring kr = rpmKeyringNew();
+	ks_rpmdb.rebuild(txn, kr);
+	rpmKeyringFree(kr);
+    }
+
+ exit:
+
+    ts->keyring = rpmKeyringFree(ts->keyring);
+    rpmKeyringFree(keyring);
+    rpmtxnEnd(txn);
+    rpmtsSetVSFlags(ts, oflags);
+
+    return rc;
+}
+
 rpmRC rpmtsImportPubkey(const rpmts ts, const unsigned char * pkt, size_t pktlen)
 {
     rpmRC rc = RPMRC_FAIL;