add support for user attributes (during canonicalization)

5 files changed, 366 insertions, 1 deletions

diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/results/OperationResult.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/results/OperationResult.java
index 1388c0eac..5884dd2d5 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/results/OperationResult.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/results/OperationResult.java
@@ -416,6 +416,21 @@ public abstract class OperationResult implements Parcelable {
         MSG_KC_UID_REVOKE_OLD (LogLevel.DEBUG, R.string.msg_kc_uid_revoke_old),
         MSG_KC_UID_REMOVE (LogLevel.DEBUG, R.string.msg_kc_uid_remove),
         MSG_KC_UID_WARN_ENCODING (LogLevel.WARN, R.string.msg_kc_uid_warn_encoding),
+        MSG_KC_UAT_JPEG (LogLevel.DEBUG, R.string.msg_kc_uat_jpeg),
+        MSG_KC_UAT_UNKNOWN (LogLevel.DEBUG, R.string.msg_kc_uat_unknown),
+        MSG_KC_UAT_BAD_ERR (LogLevel.WARN, R.string.msg_kc_uat_bad_err),
+        MSG_KC_UAT_BAD_LOCAL (LogLevel.WARN, R.string.msg_kc_uat_bad_local),
+        MSG_KC_UAT_BAD_TIME (LogLevel.WARN, R.string.msg_kc_uat_bad_time),
+        MSG_KC_UAT_BAD_TYPE (LogLevel.WARN, R.string.msg_kc_uat_bad_type),
+        MSG_KC_UAT_BAD (LogLevel.WARN, R.string.msg_kc_uat_bad),
+        MSG_KC_UAT_CERT_DUP (LogLevel.DEBUG, R.string.msg_kc_uat_cert_dup),
+        MSG_KC_UAT_DUP (LogLevel.DEBUG, R.string.msg_kc_uat_dup),
+        MSG_KC_UAT_FOREIGN (LogLevel.DEBUG, R.string.msg_kc_uat_foreign),
+        MSG_KC_UAT_NO_CERT (LogLevel.DEBUG, R.string.msg_kc_uat_no_cert),
+        MSG_KC_UAT_REVOKE_DUP (LogLevel.DEBUG, R.string.msg_kc_uat_revoke_dup),
+        MSG_KC_UAT_REVOKE_OLD (LogLevel.DEBUG, R.string.msg_kc_uat_revoke_old),
+        MSG_KC_UAT_REMOVE (LogLevel.DEBUG, R.string.msg_kc_uat_remove),
+        MSG_KC_UAT_WARN_ENCODING (LogLevel.WARN, R.string.msg_kc_uat_warn_encoding),
 
 
         // keyring consolidation
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java
index a445e161f..404228a3e 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java
@@ -21,6 +21,7 @@ package org.sufficientlysecure.keychain.pgp;
 import org.spongycastle.bcpg.ArmoredOutputStream;
 import org.spongycastle.bcpg.PublicKeyAlgorithmTags;
 import org.spongycastle.bcpg.SignatureSubpacketTags;
+import org.spongycastle.bcpg.UserAttributeSubpacketTags;
 import org.spongycastle.bcpg.sig.KeyFlags;
 import org.spongycastle.openpgp.PGPKeyRing;
 import org.spongycastle.openpgp.PGPObjectFactory;
@@ -30,6 +31,7 @@ import org.spongycastle.openpgp.PGPSecretKey;
 import org.spongycastle.openpgp.PGPSecretKeyRing;
 import org.spongycastle.openpgp.PGPSignature;
 import org.spongycastle.openpgp.PGPSignatureList;
+import org.spongycastle.openpgp.PGPUserAttributeSubpacketVector;
 import org.spongycastle.openpgp.PGPUtil;
 import org.spongycastle.openpgp.operator.jcajce.JcaKeyFingerprintCalculator;
 import org.sufficientlysecure.keychain.Constants;
@@ -605,6 +607,170 @@ public class UncachedKeyRing {
                 return null;
             }
 
+            ArrayList<PGPUserAttributeSubpacketVector> processedUserAttributes = new ArrayList<>();
+            for (PGPUserAttributeSubpacketVector userAttribute :
+                    new IterableIterator<PGPUserAttributeSubpacketVector>(masterKey.getUserAttributes())) {
+
+                if (userAttribute.getSubpacket(UserAttributeSubpacketTags.IMAGE_ATTRIBUTE) != null) {
+                    log.add(LogType.MSG_KC_UAT_JPEG, indent);
+                } else {
+                    log.add(LogType.MSG_KC_UAT_UNKNOWN, indent);
+                }
+
+                try {
+                    indent += 1;
+
+                    // check for duplicate user attributes
+                    if (processedUserAttributes.contains(userAttribute)) {
+                        log.add(LogType.MSG_KC_UAT_DUP, indent);
+                        // strip out the first found user id with this name
+                        modified = PGPPublicKey.removeCertification(modified, userAttribute);
+                    }
+                    processedUserAttributes.add(userAttribute);
+
+                    PGPSignature selfCert = null;
+                    revocation = null;
+
+                    // look through signatures for this specific user id
+                    @SuppressWarnings("unchecked")
+                    Iterator<PGPSignature> signaturesIt = masterKey.getSignaturesForUserAttribute(userAttribute);
+                    if (signaturesIt != null) {
+                        for (PGPSignature zert : new IterableIterator<PGPSignature>(signaturesIt)) {
+                            WrappedSignature cert = new WrappedSignature(zert);
+                            long certId = cert.getKeyId();
+
+                            int type = zert.getSignatureType();
+                            if (type != PGPSignature.DEFAULT_CERTIFICATION
+                                    && type != PGPSignature.NO_CERTIFICATION
+                                    && type != PGPSignature.CASUAL_CERTIFICATION
+                                    && type != PGPSignature.POSITIVE_CERTIFICATION
+                                    && type != PGPSignature.CERTIFICATION_REVOCATION) {
+                                log.add(LogType.MSG_KC_UAT_BAD_TYPE,
+                                        indent, "0x" + Integer.toString(zert.getSignatureType(), 16));
+                                modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                badCerts += 1;
+                                continue;
+                            }
+
+                            if (cert.getCreationTime().after(nowPlusOneDay)) {
+                                // Creation date in the future? No way!
+                                log.add(LogType.MSG_KC_UAT_BAD_TIME, indent);
+                                modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                badCerts += 1;
+                                continue;
+                            }
+
+                            if (cert.isLocal()) {
+                                // Creation date in the future? No way!
+                                log.add(LogType.MSG_KC_UAT_BAD_LOCAL, indent);
+                                modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                badCerts += 1;
+                                continue;
+                            }
+
+                            // If this is a foreign signature, ...
+                            if (certId != masterKeyId) {
+                                // never mind any further for public keys, but remove them from secret ones
+                                if (isSecret()) {
+                                    log.add(LogType.MSG_KC_UAT_FOREIGN,
+                                            indent, KeyFormattingUtils.convertKeyIdToHex(certId));
+                                    modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                    badCerts += 1;
+                                }
+                                continue;
+                            }
+
+                            // Otherwise, first make sure it checks out
+                            try {
+                                cert.init(masterKey);
+                                if (!cert.verifySignature(masterKey, userAttribute)) {
+                                    log.add(LogType.MSG_KC_UAT_BAD,
+                                            indent);
+                                    modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                    badCerts += 1;
+                                    continue;
+                                }
+                            } catch (PgpGeneralException e) {
+                                log.add(LogType.MSG_KC_UAT_BAD_ERR,
+                                        indent);
+                                modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                badCerts += 1;
+                                continue;
+                            }
+
+                            switch (type) {
+                                case PGPSignature.DEFAULT_CERTIFICATION:
+                                case PGPSignature.NO_CERTIFICATION:
+                                case PGPSignature.CASUAL_CERTIFICATION:
+                                case PGPSignature.POSITIVE_CERTIFICATION:
+                                    if (selfCert == null) {
+                                        selfCert = zert;
+                                    } else if (selfCert.getCreationTime().before(cert.getCreationTime())) {
+                                        log.add(LogType.MSG_KC_UAT_CERT_DUP,
+                                                indent);
+                                        modified = PGPPublicKey.removeCertification(modified, userAttribute, selfCert);
+                                        redundantCerts += 1;
+                                        selfCert = zert;
+                                    } else {
+                                        log.add(LogType.MSG_KC_UAT_CERT_DUP,
+                                                indent);
+                                        modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                        redundantCerts += 1;
+                                    }
+                                    // If there is a revocation certificate, and it's older than this, drop it
+                                    if (revocation != null
+                                            && revocation.getCreationTime().before(selfCert.getCreationTime())) {
+                                        log.add(LogType.MSG_KC_UAT_REVOKE_OLD,
+                                                indent);
+                                        modified = PGPPublicKey.removeCertification(modified, userAttribute, revocation);
+                                        revocation = null;
+                                        redundantCerts += 1;
+                                    }
+                                    break;
+
+                                case PGPSignature.CERTIFICATION_REVOCATION:
+                                    // If this is older than the (latest) self cert, drop it
+                                    if (selfCert != null && selfCert.getCreationTime().after(zert.getCreationTime())) {
+                                        log.add(LogType.MSG_KC_UAT_REVOKE_OLD,
+                                                indent);
+                                        modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                        redundantCerts += 1;
+                                        continue;
+                                    }
+                                    // first revocation? remember it.
+                                    if (revocation == null) {
+                                        revocation = zert;
+                                        // more revocations? at least one is superfluous, then.
+                                    } else if (revocation.getCreationTime().before(cert.getCreationTime())) {
+                                        log.add(LogType.MSG_KC_UAT_REVOKE_DUP,
+                                                indent);
+                                        modified = PGPPublicKey.removeCertification(modified, userAttribute, revocation);
+                                        redundantCerts += 1;
+                                        revocation = zert;
+                                    } else {
+                                        log.add(LogType.MSG_KC_UAT_REVOKE_DUP,
+                                                indent);
+                                        modified = PGPPublicKey.removeCertification(modified, userAttribute, zert);
+                                        redundantCerts += 1;
+                                    }
+                                    break;
+                            }
+                        }
+                    }
+
+                    // If no valid certificate (if only a revocation) remains, drop it
+                    if (selfCert == null && revocation == null) {
+                        log.add(LogType.MSG_KC_UAT_REMOVE,
+                                indent);
+                        modified = PGPPublicKey.removeCertification(modified, userAttribute);
+                    }
+
+                } finally {
+                    indent -= 1;
+                }
+            }
+
+
             // Replace modified key in the keyring
             ring = replacePublicKey(ring, modified);
             indent -= 1;
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSignature.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSignature.java
index c395ca52d..3dc02d3ed 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSignature.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSignature.java
@@ -29,6 +29,7 @@ import org.spongycastle.openpgp.PGPObjectFactory;
 import org.spongycastle.openpgp.PGPPublicKey;
 import org.spongycastle.openpgp.PGPSignature;
 import org.spongycastle.openpgp.PGPSignatureList;
+import org.spongycastle.openpgp.PGPUserAttributeSubpacketVector;
 import org.spongycastle.openpgp.operator.jcajce.JcaPGPContentVerifierBuilderProvider;
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException;
@@ -199,6 +200,14 @@ public class WrappedSignature {
         }
     }
 
+    boolean verifySignature(PGPPublicKey key, PGPUserAttributeSubpacketVector attribute) throws PgpGeneralException {
+        try {
+            return mSig.verifyCertification(attribute, key);
+        } catch (PGPException e) {
+            throw new PgpGeneralException("Error!", e);
+        }
+    }
+
     public boolean verifySignature(UncachedPublicKey key, byte[] rawUserId) throws PgpGeneralException {
         return verifySignature(key.getPublicKey(), rawUserId);
     }
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/affirmation/LinkedIdentity.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/affirmation/LinkedIdentity.java
new file mode 100644
index 000000000..dcbaa1c1c
--- /dev/null
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/affirmation/LinkedIdentity.java
@@ -0,0 +1,160 @@
+package org.sufficientlysecure.keychain.pgp.affirmation;
+
+import org.spongycastle.bcpg.UserAttributeSubpacket;
+import org.spongycastle.util.Strings;
+import org.spongycastle.util.encoders.Hex;
+import org.sufficientlysecure.keychain.Constants;
+import org.sufficientlysecure.keychain.util.Log;
+
+import java.net.URI;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map.Entry;
+import java.util.Set;
+
+public class LinkedIdentity {
+
+    protected byte[] mData;
+    public final String mNonce;
+    public final URI mSubUri;
+    final Set<String> mFlags;
+    final HashMap<String,String> mParams;
+
+    protected LinkedIdentity(byte[] data, String nonce, Set<String> flags,
+                             HashMap<String, String> params, URI subUri) {
+        if ( ! nonce.matches("[0-9a-zA-Z]+")) {
+            throw new AssertionError("bug: nonce must be hexstring!");
+        }
+
+        mData = data;
+        mNonce = nonce;
+        mFlags = flags;
+        mParams = params;
+        mSubUri = subUri;
+    }
+
+    LinkedIdentity(String nonce, Set<String> flags,
+                   HashMap<String, String> params, URI subUri) {
+        this(null, nonce, flags, params, subUri);
+    }
+
+    public byte[] encode() {
+        if (mData != null) {
+            return mData;
+        }
+
+        StringBuilder b = new StringBuilder();
+        b.append("pgpid:");
+
+        // add flags
+        if (mFlags != null) {
+            boolean first = true;
+            for (String flag : mFlags) {
+                if (!first) {
+                    b.append(";");
+                }
+                first = false;
+                b.append(flag);
+            }
+        }
+
+        // add parameters
+        if (mParams != null) {
+            boolean first = true;
+            Iterator<Entry<String, String>> it = mParams.entrySet().iterator();
+            while (it.hasNext()) {
+                if (!first) {
+                    b.append(";");
+                }
+                first = false;
+                Entry<String, String> entry = it.next();
+                b.append(entry.getKey()).append("=").append(entry.getValue());
+            }
+        }
+
+        b.append("@");
+        b.append(mSubUri);
+
+        byte[] nonceBytes = Hex.decode(mNonce);
+        byte[] data = Strings.toUTF8ByteArray(b.toString());
+
+        byte[] result = new byte[data.length+12];
+        System.arraycopy(nonceBytes, 0, result, 0, 12);
+        System.arraycopy(data, 0, result, 12, result.length);
+
+        return result;
+    }
+
+    /** This method parses an affirmation from a UserAttributeSubpacket, or returns null if the
+     * subpacket can not be parsed as a valid affirmation.
+     */
+    public static LinkedIdentity parseAffirmation(UserAttributeSubpacket subpacket) {
+        if (subpacket.getType() != 100) {
+            return null;
+        }
+
+        byte[] data = subpacket.getData();
+        String nonce = Hex.toHexString(data, 0, 12);
+
+        try {
+            return parseUri(nonce, Strings.fromUTF8ByteArray(Arrays.copyOfRange(data, 12, data.length)));
+
+        } catch (IllegalArgumentException e) {
+            Log.e(Constants.TAG, "error parsing uri in (suspected) affirmation packet");
+            return null;
+        }
+    }
+
+    protected static LinkedIdentity parseUri (String nonce, String uriString) {
+        URI uri = URI.create(uriString);
+
+        if ("pgpid".equals(uri.getScheme())) {
+            Log.e(Constants.TAG, "unknown uri scheme in (suspected) affirmation packet");
+            return null;
+        }
+
+        if (!uri.isOpaque()) {
+            Log.e(Constants.TAG, "non-opaque uri in (suspected) affirmation packet");
+            return null;
+        }
+
+        String specific = uri.getSchemeSpecificPart();
+        if (!specific.contains("@")) {
+            Log.e(Constants.TAG, "unknown uri scheme in affirmation packet");
+            return null;
+        }
+
+        String[] pieces = specific.split("@", 2);
+        URI subUri = URI.create(pieces[1]);
+
+        Set<String> flags = new HashSet<String>();
+        HashMap<String,String> params = new HashMap<String,String>();
+        {
+            String[] rawParams = pieces[0].split(";");
+            for (String param : rawParams) {
+                String[] p = param.split("=", 2);
+                if (p.length == 1) {
+                    flags.add(param);
+                } else {
+                    params.put(p[0], p[1]);
+                }
+            }
+        }
+
+        return new LinkedIdentity(nonce, flags, params, subUri);
+
+    }
+
+    public static String generateNonce() {
+        // TODO make this actually random
+        // byte[] data = new byte[96];
+        // new SecureRandom().nextBytes(data);
+        // return Hex.toHexString(data);
+
+        // debug for now
+        return "0123456789ABCDEF01234567";
+    }
+
+}
diff --git a/OpenKeychain/src/main/res/values/strings.xml b/OpenKeychain/src/main/res/values/strings.xml
index 301de0be1..4b5c46a5f 100644
--- a/OpenKeychain/src/main/res/values/strings.xml
+++ b/OpenKeychain/src/main/res/values/strings.xml
@@ -760,8 +760,23 @@
     <string name="msg_kc_uid_revoke_old">"Removing outdated revocation certificate for user ID '%s'"</string>
     <string name="msg_kc_uid_no_cert">"No valid self-certificate found for user ID '%s', removing from ring"</string>
     <string name="msg_kc_uid_remove">"Removing invalid user ID '%s'"</string>
-    <string name="msg_kc_uid_dup">"Removing duplicate user ID '%s'. The secret key contained two of them. This may result in missing certificates!"</string>
+    <string name="msg_kc_uid_dup">"Removing duplicate user ID '%s'. The keyring contained two of them. This may result in missing certificates!"</string>
     <string name="msg_kc_uid_warn_encoding">"User id does not verify as UTF-8!"</string>
+    <string name="msg_kc_uat_jpeg">"Processing user attribute of type JPEG"</string>
+    <string name="msg_kc_uat_unknown">"Processing user attribute of unknown type"</string>
+    <string name="msg_kc_uat_bad_err">"Removing bad self certificate for user attribute"</string>
+    <string name="msg_kc_uat_bad_local">"Removing user attribute certificate with 'local' flag"</string>
+    <string name="msg_kc_uat_bad_time">"Removing user attribute with future timestamp"</string>
+    <string name="msg_kc_uat_bad_type">"Removing user attribute certificate of unknown type (%s)"</string>
+    <string name="msg_kc_uat_bad">"Removing bad self certificate for user attribute"</string>
+    <string name="msg_kc_uat_cert_dup">"Removing outdated self certificate for user attribute"</string>
+    <string name="msg_kc_uat_dup">"Removing duplicate user attribute. The keyring contained two of them. This may result in missing certificates!"</string>
+    <string name="msg_kc_uat_foreign">"Removing foreign user attribute certificate by"</string>
+    <string name="msg_kc_uat_revoke_dup">"Removing redundant revocation certificate for user attribute"</string>
+    <string name="msg_kc_uat_revoke_old">"Removing outdated revocation certificate for user attribute"</string>
+    <string name="msg_kc_uat_no_cert">"No valid self-certificate found for user attribute, removing from ring"</string>
+    <string name="msg_kc_uat_remove">"Removing invalid user attribute"</string>
+    <string name="msg_kc_uat_warn_encoding">"User id does not verify as UTF-8!"</string>
 
     <!-- Keyring merging log entries -->
     <string name="msg_mg_error_secret_dummy">"New public subkey found, but secret subkey dummy generation is not supported!"</string>