diff options
Diffstat (limited to 'OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java')
| -rw-r--r-- | OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java | 644 |
1 files changed, 644 insertions, 0 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java new file mode 100644 index 000000000..4c786f555 --- /dev/null +++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java @@ -0,0 +1,644 @@ +/* + * Copyright (C) 2012-2013 Dominik Schürmann <dominik@dominikschuermann.de> + * Copyright (C) 2010 Thialfihar <thi@thialfihar.org> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.sufficientlysecure.keychain.pgp; + +import android.content.Context; +import android.graphics.Color; +import android.text.Spannable; +import android.text.SpannableStringBuilder; +import android.text.style.ForegroundColorSpan; + +import org.spongycastle.bcpg.sig.KeyFlags; +import org.spongycastle.openpgp.PGPPublicKey; +import org.spongycastle.openpgp.PGPPublicKeyRing; +import org.spongycastle.openpgp.PGPSecretKey; +import org.spongycastle.openpgp.PGPSecretKeyRing; +import org.spongycastle.openpgp.PGPSignature; +import org.spongycastle.openpgp.PGPSignatureSubpacketVector; +import org.spongycastle.util.encoders.Hex; +import org.sufficientlysecure.keychain.Constants; +import org.sufficientlysecure.keychain.R; +import org.sufficientlysecure.keychain.provider.ProviderHelper; +import org.sufficientlysecure.keychain.util.IterableIterator; +import org.sufficientlysecure.keychain.util.Log; + +import java.security.DigestException; +import java.security.MessageDigest; +import java.security.NoSuchAlgorithmException; +import java.util.Calendar; +import java.util.Date; +import java.util.GregorianCalendar; +import java.util.Locale; +import java.util.Vector; +import java.util.regex.Matcher; +import java.util.regex.Pattern; + +public class PgpKeyHelper { + + private static final Pattern USER_ID_PATTERN = Pattern.compile("^(.*?)(?: \\((.*)\\))?(?: <(.*)>)?$"); + + public static Date getCreationDate(PGPPublicKey key) { + return key.getCreationTime(); + } + + public static Date getCreationDate(PGPSecretKey key) { + return key.getPublicKey().getCreationTime(); + } + + @SuppressWarnings("unchecked") + public static PGPSecretKey getKeyNum(PGPSecretKeyRing keyRing, long num) { + long cnt = 0; + if (keyRing == null) { + return null; + } + for (PGPSecretKey key : new IterableIterator<PGPSecretKey>(keyRing.getSecretKeys())) { + if (cnt == num) { + return key; + } + cnt++; + } + + return null; + } + + @SuppressWarnings("unchecked") + public static Vector<PGPPublicKey> getEncryptKeys(PGPPublicKeyRing keyRing) { + Vector<PGPPublicKey> encryptKeys = new Vector<PGPPublicKey>(); + + for (PGPPublicKey key : new IterableIterator<PGPPublicKey>(keyRing.getPublicKeys())) { + if (isEncryptionKey(key)) { + encryptKeys.add(key); + } + } + + return encryptKeys; + } + + @SuppressWarnings("unchecked") + public static Vector<PGPSecretKey> getSigningKeys(PGPSecretKeyRing keyRing) { + Vector<PGPSecretKey> signingKeys = new Vector<PGPSecretKey>(); + + for (PGPSecretKey key : new IterableIterator<PGPSecretKey>(keyRing.getSecretKeys())) { + if (isSigningKey(key)) { + signingKeys.add(key); + } + } + + return signingKeys; + } + + @SuppressWarnings("unchecked") + public static Vector<PGPSecretKey> getCertificationKeys(PGPSecretKeyRing keyRing) { + Vector<PGPSecretKey> signingKeys = new Vector<PGPSecretKey>(); + + for (PGPSecretKey key : new IterableIterator<PGPSecretKey>(keyRing.getSecretKeys())) { + if (isCertificationKey(key)) { + signingKeys.add(key); + } + } + + return signingKeys; + } + + public static Vector<PGPPublicKey> getUsableEncryptKeys(PGPPublicKeyRing keyRing) { + Vector<PGPPublicKey> usableKeys = new Vector<PGPPublicKey>(); + Vector<PGPPublicKey> encryptKeys = getEncryptKeys(keyRing); + PGPPublicKey masterKey = null; + for (int i = 0; i < encryptKeys.size(); ++i) { + PGPPublicKey key = encryptKeys.get(i); + if (!isExpired(key) && !key.isRevoked()) { + if (key.isMasterKey()) { + masterKey = key; + } else { + usableKeys.add(key); + } + } + } + if (masterKey != null) { + usableKeys.add(masterKey); + } + return usableKeys; + } + + public static boolean isExpired(PGPPublicKey key) { + Date creationDate = getCreationDate(key); + Date expiryDate = getExpiryDate(key); + Date now = new Date(); + if (now.compareTo(creationDate) >= 0 + && (expiryDate == null || now.compareTo(expiryDate) <= 0)) { + return false; + } + return true; + } + + public static Vector<PGPSecretKey> getUsableCertificationKeys(PGPSecretKeyRing keyRing) { + Vector<PGPSecretKey> usableKeys = new Vector<PGPSecretKey>(); + Vector<PGPSecretKey> signingKeys = getCertificationKeys(keyRing); + PGPSecretKey masterKey = null; + for (int i = 0; i < signingKeys.size(); ++i) { + PGPSecretKey key = signingKeys.get(i); + if (key.isMasterKey()) { + masterKey = key; + } else { + usableKeys.add(key); + } + } + if (masterKey != null) { + usableKeys.add(masterKey); + } + return usableKeys; + } + + public static Vector<PGPSecretKey> getUsableSigningKeys(PGPSecretKeyRing keyRing) { + Vector<PGPSecretKey> usableKeys = new Vector<PGPSecretKey>(); + Vector<PGPSecretKey> signingKeys = getSigningKeys(keyRing); + PGPSecretKey masterKey = null; + for (int i = 0; i < signingKeys.size(); ++i) { + PGPSecretKey key = signingKeys.get(i); + if (key.isMasterKey()) { + masterKey = key; + } else { + usableKeys.add(key); + } + } + if (masterKey != null) { + usableKeys.add(masterKey); + } + return usableKeys; + } + + public static Date getExpiryDate(PGPPublicKey key) { + Date creationDate = getCreationDate(key); + if (key.getValidDays() == 0) { + // no expiry + return null; + } + Calendar calendar = GregorianCalendar.getInstance(); + calendar.setTime(creationDate); + calendar.add(Calendar.DATE, key.getValidDays()); + + return calendar.getTime(); + } + + public static Date getExpiryDate(PGPSecretKey key) { + return getExpiryDate(key.getPublicKey()); + } + + public static PGPPublicKey getEncryptPublicKey(Context context, long masterKeyId) { + PGPPublicKeyRing keyRing = ProviderHelper.getPGPPublicKeyRing(context, masterKeyId); + if (keyRing == null) { + Log.e(Constants.TAG, "keyRing is null!"); + return null; + } + Vector<PGPPublicKey> encryptKeys = getUsableEncryptKeys(keyRing); + if (encryptKeys.size() == 0) { + Log.e(Constants.TAG, "encryptKeys is null!"); + return null; + } + return encryptKeys.get(0); + } + + public static PGPSecretKey getCertificationKey(Context context, long masterKeyId) { + PGPSecretKeyRing keyRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId); + if (keyRing == null) { + return null; + } + Vector<PGPSecretKey> signingKeys = getUsableCertificationKeys(keyRing); + if (signingKeys.size() == 0) { + return null; + } + return signingKeys.get(0); + } + + public static PGPSecretKey getSigningKey(Context context, long masterKeyId) { + PGPSecretKeyRing keyRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId); + if (keyRing == null) { + return null; + } + Vector<PGPSecretKey> signingKeys = getUsableSigningKeys(keyRing); + if (signingKeys.size() == 0) { + return null; + } + return signingKeys.get(0); + } + + @SuppressWarnings("unchecked") + public static String getMainUserId(PGPPublicKey key) { + for (String userId : new IterableIterator<String>(key.getUserIDs())) { + return userId; + } + return null; + } + + @SuppressWarnings("unchecked") + public static String getMainUserId(PGPSecretKey key) { + for (String userId : new IterableIterator<String>(key.getUserIDs())) { + return userId; + } + return null; + } + + public static String getMainUserIdSafe(Context context, PGPPublicKey key) { + String userId = getMainUserId(key); + if (userId == null || userId.equals("")) { + userId = context.getString(R.string.user_id_no_name); + } + return userId; + } + + public static String getMainUserIdSafe(Context context, PGPSecretKey key) { + String userId = getMainUserId(key); + if (userId == null || userId.equals("")) { + userId = context.getString(R.string.user_id_no_name); + } + return userId; + } + + public static int getKeyUsage(PGPSecretKey key) { + return getKeyUsage(key.getPublicKey()); + } + + @SuppressWarnings("unchecked") + private static int getKeyUsage(PGPPublicKey key) { + int usage = 0; + if (key.getVersion() >= 4) { + for (PGPSignature sig : new IterableIterator<PGPSignature>(key.getSignatures())) { + if (key.isMasterKey() && sig.getKeyID() != key.getKeyID()) { + continue; + } + + PGPSignatureSubpacketVector hashed = sig.getHashedSubPackets(); + if (hashed != null) { + usage |= hashed.getKeyFlags(); + } + + PGPSignatureSubpacketVector unhashed = sig.getUnhashedSubPackets(); + if (unhashed != null) { + usage |= unhashed.getKeyFlags(); + } + } + } + return usage; + } + + @SuppressWarnings("unchecked") + public static boolean isEncryptionKey(PGPPublicKey key) { + if (!key.isEncryptionKey()) { + return false; + } + + if (key.getVersion() <= 3) { + // this must be true now + return key.isEncryptionKey(); + } + + // special cases + if (key.getAlgorithm() == PGPPublicKey.ELGAMAL_ENCRYPT) { + return true; + } + + if (key.getAlgorithm() == PGPPublicKey.RSA_ENCRYPT) { + return true; + } + + for (PGPSignature sig : new IterableIterator<PGPSignature>(key.getSignatures())) { + if (key.isMasterKey() && sig.getKeyID() != key.getKeyID()) { + continue; + } + PGPSignatureSubpacketVector hashed = sig.getHashedSubPackets(); + + if (hashed != null + && (hashed.getKeyFlags() & (KeyFlags.ENCRYPT_COMMS | KeyFlags.ENCRYPT_STORAGE)) != 0) { + return true; + } + + PGPSignatureSubpacketVector unhashed = sig.getUnhashedSubPackets(); + + if (unhashed != null + && (unhashed.getKeyFlags() & (KeyFlags.ENCRYPT_COMMS | KeyFlags.ENCRYPT_STORAGE)) != 0) { + return true; + } + } + return false; + } + + public static boolean isEncryptionKey(PGPSecretKey key) { + return isEncryptionKey(key.getPublicKey()); + } + + @SuppressWarnings("unchecked") + public static boolean isSigningKey(PGPPublicKey key) { + if (key.getVersion() <= 3) { + return true; + } + + // special case + if (key.getAlgorithm() == PGPPublicKey.RSA_SIGN) { + return true; + } + + for (PGPSignature sig : new IterableIterator<PGPSignature>(key.getSignatures())) { + if (key.isMasterKey() && sig.getKeyID() != key.getKeyID()) { + continue; + } + PGPSignatureSubpacketVector hashed = sig.getHashedSubPackets(); + + if (hashed != null && (hashed.getKeyFlags() & KeyFlags.SIGN_DATA) != 0) { + return true; + } + + PGPSignatureSubpacketVector unhashed = sig.getUnhashedSubPackets(); + + if (unhashed != null && (unhashed.getKeyFlags() & KeyFlags.SIGN_DATA) != 0) { + return true; + } + } + + return false; + } + + public static boolean isSigningKey(PGPSecretKey key) { + return isSigningKey(key.getPublicKey()); + } + + @SuppressWarnings("unchecked") + public static boolean isCertificationKey(PGPPublicKey key) { + if (key.getVersion() <= 3) { + return true; + } + + for (PGPSignature sig : new IterableIterator<PGPSignature>(key.getSignatures())) { + if (key.isMasterKey() && sig.getKeyID() != key.getKeyID()) { + continue; + } + PGPSignatureSubpacketVector hashed = sig.getHashedSubPackets(); + + if (hashed != null && (hashed.getKeyFlags() & KeyFlags.CERTIFY_OTHER) != 0) { + return true; + } + + PGPSignatureSubpacketVector unhashed = sig.getUnhashedSubPackets(); + + if (unhashed != null && (unhashed.getKeyFlags() & KeyFlags.CERTIFY_OTHER) != 0) { + return true; + } + } + + return false; + } + + public static boolean isAuthenticationKey(PGPSecretKey key) { + return isAuthenticationKey(key.getPublicKey()); + } + + @SuppressWarnings("unchecked") + public static boolean isAuthenticationKey(PGPPublicKey key) { + if (key.getVersion() <= 3) { + return true; + } + + for (PGPSignature sig : new IterableIterator<PGPSignature>(key.getSignatures())) { + if (key.isMasterKey() && sig.getKeyID() != key.getKeyID()) { + continue; + } + PGPSignatureSubpacketVector hashed = sig.getHashedSubPackets(); + + if (hashed != null && (hashed.getKeyFlags() & KeyFlags.AUTHENTICATION) != 0) { + return true; + } + + PGPSignatureSubpacketVector unhashed = sig.getUnhashedSubPackets(); + + if (unhashed != null && (unhashed.getKeyFlags() & KeyFlags.AUTHENTICATION) != 0) { + return true; + } + } + + return false; + } + + public static boolean isCertificationKey(PGPSecretKey key) { + return isCertificationKey(key.getPublicKey()); + } + + public static String getAlgorithmInfo(PGPPublicKey key) { + return getAlgorithmInfo(key.getAlgorithm(), key.getBitStrength()); + } + + public static String getAlgorithmInfo(PGPSecretKey key) { + return getAlgorithmInfo(key.getPublicKey()); + } + + public static String getAlgorithmInfo(int algorithm, int keySize) { + String algorithmStr; + + switch (algorithm) { + case PGPPublicKey.RSA_ENCRYPT: + case PGPPublicKey.RSA_GENERAL: + case PGPPublicKey.RSA_SIGN: { + algorithmStr = "RSA"; + break; + } + case PGPPublicKey.DSA: { + algorithmStr = "DSA"; + break; + } + + case PGPPublicKey.ELGAMAL_ENCRYPT: + case PGPPublicKey.ELGAMAL_GENERAL: { + algorithmStr = "ElGamal"; + break; + } + + default: { + algorithmStr = "Unknown"; + break; + } + } + if(keySize > 0) + return algorithmStr + ", " + keySize + " bit"; + else + return algorithmStr; + } + + /** + * Converts fingerprint to hex (optional: with whitespaces after 4 characters) + * <p/> + * Fingerprint is shown using lowercase characters. Studies have shown that humans can + * better differentiate between numbers and letters when letters are lowercase. + * + * @param fingerprint + * @return + */ + public static String convertFingerprintToHex(byte[] fingerprint) { + String hexString = Hex.toHexString(fingerprint); + + return hexString; + } + + /** + * Convert key id from long to 64 bit hex string + * <p/> + * V4: "The Key ID is the low-order 64 bits of the fingerprint" + * <p/> + * see http://tools.ietf.org/html/rfc4880#section-12.2 + * + * @param keyId + * @return + */ + public static String convertKeyIdToHex(long keyId) { + long upper = keyId >> 32; + if (upper == 0) { + // this is a short key id + return convertKeyIdToHexShort(keyId); + } + return "0x" + convertKeyIdToHex32bit(keyId >> 32) + convertKeyIdToHex32bit(keyId); + } + + public static String convertKeyIdToHexShort(long keyId) { + return "0x" + convertKeyIdToHex32bit(keyId); + } + + private static String convertKeyIdToHex32bit(long keyId) { + String hexString = Long.toHexString(keyId & 0xffffffffL).toLowerCase(Locale.US); + while (hexString.length() < 8) { + hexString = "0" + hexString; + } + return hexString; + } + + + public static SpannableStringBuilder colorizeFingerprint(String fingerprint) { + // split by 4 characters + fingerprint = fingerprint.replaceAll("(.{4})(?!$)", "$1 "); + + // add line breaks to have a consistent "image" that can be recognized + char[] chars = fingerprint.toCharArray(); + chars[24] = '\n'; + fingerprint = String.valueOf(chars); + + SpannableStringBuilder sb = new SpannableStringBuilder(fingerprint); + try { + // for each 4 characters of the fingerprint + 1 space + for (int i = 0; i < fingerprint.length(); i += 5) { + int spanEnd = Math.min(i + 4, fingerprint.length()); + String fourChars = fingerprint.substring(i, spanEnd); + + int raw = Integer.parseInt(fourChars, 16); + byte[] bytes = {(byte) ((raw >> 8) & 0xff - 128), (byte) (raw & 0xff - 128)}; + int[] color = getRgbForData(bytes); + int r = color[0]; + int g = color[1]; + int b = color[2]; + + // we cannot change black by multiplication, so adjust it to an almost-black grey, + // which will then be brightened to the minimal brightness level + if (r == 0 && g == 0 && b == 0) { + r = 1; + g = 1; + b = 1; + } + + // Convert rgb to brightness + double brightness = 0.2126 * r + 0.7152 * g + 0.0722 * b; + + // If a color is too dark to be seen on black, + // then brighten it up to a minimal brightness. + if (brightness < 80) { + double factor = 80.0 / brightness; + r = Math.min(255, (int) (r * factor)); + g = Math.min(255, (int) (g * factor)); + b = Math.min(255, (int) (b * factor)); + + // If it is too light, then darken it to a respective maximal brightness. + } else if (brightness > 180) { + double factor = 180.0 / brightness; + r = (int) (r * factor); + g = (int) (g * factor); + b = (int) (b * factor); + } + + // Create a foreground color with the 3 digest integers as RGB + // and then converting that int to hex to use as a color + sb.setSpan(new ForegroundColorSpan(Color.rgb(r, g, b)), + i, spanEnd, Spannable.SPAN_INCLUSIVE_INCLUSIVE); + } + } catch (Exception e) { + Log.e(Constants.TAG, "Colorization failed", e); + // if anything goes wrong, then just display the fingerprint without colour, + // instead of partially correct colour or wrong colours + return new SpannableStringBuilder(fingerprint); + } + + return sb; + } + + /** + * Converts the given bytes to a unique RGB color using SHA1 algorithm + * + * @param bytes + * @return an integer array containing 3 numeric color representations (Red, Green, Black) + * @throws java.security.NoSuchAlgorithmException + * @throws java.security.DigestException + */ + private static int[] getRgbForData(byte[] bytes) throws NoSuchAlgorithmException, DigestException { + MessageDigest md = MessageDigest.getInstance("SHA1"); + + md.update(bytes); + byte[] digest = md.digest(); + + int[] result = {((int) digest[0] + 256) % 256, + ((int) digest[1] + 256) % 256, + ((int) digest[2] + 256) % 256}; + return result; + } + + /** + * Splits userId string into naming part, email part, and comment part + * + * @param userId + * @return array with naming (0), email (1), comment (2) + */ + public static String[] splitUserId(String userId) { + String[] result = new String[]{null, null, null}; + + if (userId == null || userId.equals("")) { + return result; + } + + /* + * User ID matching: + * http://fiddle.re/t4p6f + * + * test cases: + * "Max Mustermann (this is a comment) <max@example.com>" + * "Max Mustermann <max@example.com>" + * "Max Mustermann (this is a comment)" + * "Max Mustermann [this is nothing]" + */ + Matcher matcher = USER_ID_PATTERN.matcher(userId); + if (matcher.matches()) { + result[0] = matcher.group(1); + result[1] = matcher.group(3); + result[2] = matcher.group(2); + } + + return result; + } + +} |