| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * 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 android.security; |
| |
| import android.content.Context; |
| import android.text.TextUtils; |
| |
| import java.math.BigInteger; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.PrivateKey; |
| import java.security.cert.Certificate; |
| import java.security.spec.AlgorithmParameterSpec; |
| import java.util.Date; |
| |
| import javax.security.auth.x500.X500Principal; |
| |
| /** |
| * This provides the required parameters needed for initializing the |
| * {@code KeyPairGenerator} that works with |
| * <a href="{@docRoot}training/articles/keystore.html">Android KeyStore |
| * facility</a>. The Android KeyStore facility is accessed through a |
| * {@link java.security.KeyPairGenerator} API using the {@code AndroidKeyStore} |
| * provider. The {@code context} passed in may be used to pop up some UI to ask |
| * the user to unlock or initialize the Android KeyStore facility. |
| * <p> |
| * After generation, the {@code keyStoreAlias} is used with the |
| * {@link java.security.KeyStore#getEntry(String, java.security.KeyStore.ProtectionParameter)} |
| * interface to retrieve the {@link PrivateKey} and its associated |
| * {@link Certificate} chain. |
| * <p> |
| * The KeyPair generator will create a self-signed certificate with the subject |
| * as its X.509v3 Subject Distinguished Name and as its X.509v3 Issuer |
| * Distinguished Name along with the other parameters specified with the |
| * {@link Builder}. |
| * <p> |
| * The self-signed X.509 certificate may be replaced at a later time by a |
| * certificate signed by a real Certificate Authority. |
| */ |
| public final class KeyPairGeneratorSpec implements AlgorithmParameterSpec { |
| |
| private static final X500Principal DEFAULT_CERT_SUBJECT = new X500Principal("CN=fake"); |
| private static final BigInteger DEFAULT_CERT_SERIAL_NUMBER = new BigInteger("1"); |
| private static final Date DEFAULT_CERT_NOT_BEFORE = new Date(0L); // Jan 1 1970 |
| private static final Date DEFAULT_CERT_NOT_AFTER = new Date(2461449600000L); // Jan 1 2048 |
| |
| private final Context mContext; |
| |
| private final String mKeystoreAlias; |
| |
| private final String mKeyType; |
| |
| private final int mKeySize; |
| |
| private final AlgorithmParameterSpec mSpec; |
| |
| private final X500Principal mSubjectDN; |
| |
| private final BigInteger mSerialNumber; |
| |
| private final Date mStartDate; |
| |
| private final Date mEndDate; |
| |
| private final int mFlags; |
| |
| private final Date mKeyValidityStart; |
| |
| private final Date mKeyValidityForOriginationEnd; |
| |
| private final Date mKeyValidityForConsumptionEnd; |
| |
| private final @KeyStoreKeyProperties.PurposeEnum int mPurposes; |
| |
| private final String[] mDigests; |
| |
| private final String[] mEncryptionPaddings; |
| |
| private final String[] mSignaturePaddings; |
| |
| private final String[] mBlockModes; |
| |
| private final boolean mRandomizedEncryptionRequired; |
| |
| private final @KeyStoreKeyProperties.UserAuthenticatorEnum int mUserAuthenticators; |
| |
| private final int mUserAuthenticationValidityDurationSeconds; |
| |
| /** |
| * Parameter specification for the "{@code AndroidKeyPairGenerator}" |
| * instance of the {@link java.security.KeyPairGenerator} API. The |
| * {@code context} passed in may be used to pop up some UI to ask the user |
| * to unlock or initialize the Android keystore facility. |
| * <p> |
| * After generation, the {@code keyStoreAlias} is used with the |
| * {@link java.security.KeyStore#getEntry(String, java.security.KeyStore.ProtectionParameter)} |
| * interface to retrieve the {@link PrivateKey} and its associated |
| * {@link Certificate} chain. |
| * <p> |
| * The KeyPair generator will create a self-signed certificate with the |
| * properties of {@code subjectDN} as its X.509v3 Subject Distinguished Name |
| * and as its X.509v3 Issuer Distinguished Name, using the specified |
| * {@code serialNumber}, and the validity date starting at {@code startDate} |
| * and ending at {@code endDate}. |
| * |
| * @param context Android context for the activity |
| * @param keyStoreAlias name to use for the generated key in the Android |
| * keystore |
| * @param keyType key algorithm to use (EC, RSA) |
| * @param keySize size of key to generate |
| * @param spec the underlying key type parameters |
| * @param subjectDN X.509 v3 Subject Distinguished Name |
| * @param serialNumber X509 v3 certificate serial number |
| * @param startDate the start of the self-signed certificate validity period |
| * @param endDate the end date of the self-signed certificate validity |
| * period |
| * @throws IllegalArgumentException when any argument is {@code null} or |
| * {@code endDate} is before {@code startDate}. |
| * @hide should be built with KeyPairGeneratorSpecBuilder |
| */ |
| public KeyPairGeneratorSpec(Context context, String keyStoreAlias, String keyType, int keySize, |
| AlgorithmParameterSpec spec, X500Principal subjectDN, BigInteger serialNumber, |
| Date startDate, Date endDate, int flags, |
| Date keyValidityStart, |
| Date keyValidityForOriginationEnd, |
| Date keyValidityForConsumptionEnd, |
| @KeyStoreKeyProperties.PurposeEnum int purposes, |
| String[] digests, |
| String[] encryptionPaddings, |
| String[] signaturePaddings, |
| String[] blockModes, |
| boolean randomizedEncryptionRequired, |
| @KeyStoreKeyProperties.UserAuthenticatorEnum int userAuthenticators, |
| int userAuthenticationValidityDurationSeconds) { |
| if (context == null) { |
| throw new IllegalArgumentException("context == null"); |
| } else if (TextUtils.isEmpty(keyStoreAlias)) { |
| throw new IllegalArgumentException("keyStoreAlias must not be empty"); |
| } else if ((userAuthenticationValidityDurationSeconds < 0) |
| && (userAuthenticationValidityDurationSeconds != -1)) { |
| throw new IllegalArgumentException( |
| "userAuthenticationValidityDurationSeconds must not be negative"); |
| } |
| |
| if (subjectDN == null) { |
| subjectDN = DEFAULT_CERT_SUBJECT; |
| } |
| if (startDate == null) { |
| startDate = DEFAULT_CERT_NOT_BEFORE; |
| } |
| if (endDate == null) { |
| endDate = DEFAULT_CERT_NOT_AFTER; |
| } |
| if (serialNumber == null) { |
| serialNumber = DEFAULT_CERT_SERIAL_NUMBER; |
| } |
| |
| if (endDate.before(startDate)) { |
| throw new IllegalArgumentException("endDate < startDate"); |
| } |
| |
| mContext = context; |
| mKeystoreAlias = keyStoreAlias; |
| mKeyType = keyType; |
| mKeySize = keySize; |
| mSpec = spec; |
| mSubjectDN = subjectDN; |
| mSerialNumber = serialNumber; |
| mStartDate = startDate; |
| mEndDate = endDate; |
| mFlags = flags; |
| mKeyValidityStart = keyValidityStart; |
| mKeyValidityForOriginationEnd = keyValidityForOriginationEnd; |
| mKeyValidityForConsumptionEnd = keyValidityForConsumptionEnd; |
| mPurposes = purposes; |
| mDigests = ArrayUtils.cloneIfNotEmpty(ArrayUtils.nullToEmpty(digests)); |
| mEncryptionPaddings = |
| ArrayUtils.cloneIfNotEmpty(ArrayUtils.nullToEmpty(encryptionPaddings)); |
| mSignaturePaddings = ArrayUtils.cloneIfNotEmpty(ArrayUtils.nullToEmpty(signaturePaddings)); |
| mBlockModes = ArrayUtils.cloneIfNotEmpty(ArrayUtils.nullToEmpty(blockModes)); |
| mRandomizedEncryptionRequired = randomizedEncryptionRequired; |
| mUserAuthenticators = userAuthenticators; |
| mUserAuthenticationValidityDurationSeconds = userAuthenticationValidityDurationSeconds; |
| } |
| |
| /** |
| * TODO: Remove this constructor once tests are switched over to the new one above. |
| * @hide |
| */ |
| public KeyPairGeneratorSpec(Context context, String keyStoreAlias, String keyType, int keySize, |
| AlgorithmParameterSpec spec, X500Principal subjectDN, BigInteger serialNumber, |
| Date startDate, Date endDate, int flags) { |
| this(context, |
| keyStoreAlias, |
| keyType, |
| keySize, |
| spec, |
| subjectDN, |
| serialNumber, |
| startDate, |
| endDate, |
| flags, |
| startDate, |
| endDate, |
| endDate, |
| 0, // purposes |
| null, // digests |
| null, // encryption paddings |
| null, // signature paddings |
| null, // block modes |
| false, // randomized encryption required |
| 0, // user authenticators |
| -1 // user authentication validity duration (seconds) |
| ); |
| } |
| |
| /** |
| * Gets the Android context used for operations with this instance. |
| */ |
| public Context getContext() { |
| return mContext; |
| } |
| |
| /** |
| * Returns the alias that will be used in the {@code java.security.KeyStore} |
| * in conjunction with the {@code AndroidKeyStore}. |
| */ |
| public String getKeystoreAlias() { |
| return mKeystoreAlias; |
| } |
| |
| /** |
| * Returns the key type (e.g., "EC", "RSA") specified by this parameter. |
| */ |
| public String getKeyType() { |
| return mKeyType; |
| } |
| |
| /** |
| * Returns the key size specified by this parameter. For instance, for RSA |
| * this will return the modulus size and for EC it will return the field |
| * size. |
| */ |
| public int getKeySize() { |
| return mKeySize; |
| } |
| |
| /** |
| * Returns the {@link AlgorithmParameterSpec} that will be used for creation |
| * of the key pair. |
| */ |
| public AlgorithmParameterSpec getAlgorithmParameterSpec() { |
| return mSpec; |
| } |
| |
| /** |
| * Gets the subject distinguished name to be used on the X.509 certificate |
| * that will be put in the {@link java.security.KeyStore}. |
| */ |
| public X500Principal getSubjectDN() { |
| return mSubjectDN; |
| } |
| |
| /** |
| * Gets the serial number to be used on the X.509 certificate that will be |
| * put in the {@link java.security.KeyStore}. |
| */ |
| public BigInteger getSerialNumber() { |
| return mSerialNumber; |
| } |
| |
| /** |
| * Gets the start date to be used on the X.509 certificate that will be put |
| * in the {@link java.security.KeyStore}. |
| */ |
| public Date getStartDate() { |
| return mStartDate; |
| } |
| |
| /** |
| * Gets the end date to be used on the X.509 certificate that will be put in |
| * the {@link java.security.KeyStore}. |
| */ |
| public Date getEndDate() { |
| return mEndDate; |
| } |
| |
| /** |
| * @hide |
| */ |
| int getFlags() { |
| return mFlags; |
| } |
| |
| /** |
| * Returns {@code true} if this parameter will require generated keys to be |
| * encrypted in the {@link java.security.KeyStore}. |
| */ |
| public boolean isEncryptionRequired() { |
| return (mFlags & KeyStore.FLAG_ENCRYPTED) != 0; |
| } |
| |
| /** |
| * Gets the time instant before which the key pair is not yet valid. |
| * |
| * @return instant or {@code null} if not restricted. |
| * |
| * @hide |
| */ |
| public Date getKeyValidityStart() { |
| return mKeyValidityStart; |
| } |
| |
| /** |
| * Gets the time instant after which the key pair is no longer valid for decryption and |
| * verification. |
| * |
| * @return instant or {@code null} if not restricted. |
| * |
| * @hide |
| */ |
| public Date getKeyValidityForConsumptionEnd() { |
| return mKeyValidityForConsumptionEnd; |
| } |
| |
| /** |
| * Gets the time instant after which the key pair is no longer valid for encryption and signing. |
| * |
| * @return instant or {@code null} if not restricted. |
| * |
| * @hide |
| */ |
| public Date getKeyValidityForOriginationEnd() { |
| return mKeyValidityForOriginationEnd; |
| } |
| |
| /** |
| * Gets the set of purposes for which the key can be used. |
| * |
| * @hide |
| */ |
| public @KeyStoreKeyProperties.PurposeEnum int getPurposes() { |
| return mPurposes; |
| } |
| |
| /** |
| * Gets the set of digest algorithms with which the key can be used. |
| * |
| * @hide |
| */ |
| public String[] getDigests() { |
| return ArrayUtils.cloneIfNotEmpty(mDigests); |
| } |
| |
| /** |
| * Gets the set of padding schemes with which the key can be used when encrypting/decrypting. |
| * |
| * @hide |
| */ |
| public String[] getEncryptionPaddings() { |
| return ArrayUtils.cloneIfNotEmpty(mEncryptionPaddings); |
| } |
| |
| /** |
| * Gets the set of padding schemes with which the key can be used when signing/verifying. |
| * |
| * @hide |
| */ |
| public String[] getSignaturePaddings() { |
| return ArrayUtils.cloneIfNotEmpty(mSignaturePaddings); |
| } |
| |
| /** |
| * Gets the set of block modes with which the key can be used. |
| * |
| * @hide |
| */ |
| public String[] getBlockModes() { |
| return ArrayUtils.cloneIfNotEmpty(mBlockModes); |
| } |
| |
| /** |
| * Returns {@code true} if encryption using this key must be sufficiently randomized to produce |
| * different ciphertexts for the same plaintext every time. The formal cryptographic property |
| * being required is <em>indistinguishability under chosen-plaintext attack ({@code |
| * IND-CPA})</em>. This property is important because it mitigates several classes of |
| * weaknesses due to which ciphertext may leak information about plaintext. For example, if a |
| * given plaintext always produces the same ciphertext, an attacker may see the repeated |
| * ciphertexts and be able to deduce something about the plaintext. |
| * |
| * @hide |
| */ |
| public boolean isRandomizedEncryptionRequired() { |
| return mRandomizedEncryptionRequired; |
| } |
| |
| /** |
| * Gets the set of user authenticators which protect access to the private key. The key can only |
| * be used iff the user has authenticated to at least one of these user authenticators. |
| * |
| * <p>This restriction applies only to private key operations. Public key operations are not |
| * restricted. |
| * |
| * @return user authenticators or {@code 0} if the key can be used without user authentication. |
| * |
| * @hide |
| */ |
| public @KeyStoreKeyProperties.UserAuthenticatorEnum int getUserAuthenticators() { |
| return mUserAuthenticators; |
| } |
| |
| /** |
| * Gets the duration of time (seconds) for which the private key can be used after the user |
| * successfully authenticates to one of the associated user authenticators. |
| * |
| * <p>This restriction applies only to private key operations. Public key operations are not |
| * restricted. |
| * |
| * @return duration in seconds or {@code -1} if not restricted. {@code 0} means authentication |
| * is required for every use of the key. |
| * |
| * @hide |
| */ |
| public int getUserAuthenticationValidityDurationSeconds() { |
| return mUserAuthenticationValidityDurationSeconds; |
| } |
| |
| /** |
| * Builder class for {@link KeyPairGeneratorSpec} objects. |
| * <p> |
| * This will build a parameter spec for use with the <a href="{@docRoot} |
| * training/articles/keystore.html">Android KeyStore facility</a>. |
| * <p> |
| * The required fields must be filled in with the builder. |
| * <p> |
| * Example: |
| * |
| * <pre class="prettyprint"> |
| * Calendar start = new Calendar(); |
| * Calendar end = new Calendar(); |
| * end.add(1, Calendar.YEAR); |
| * |
| * KeyPairGeneratorSpec spec = |
| * new KeyPairGeneratorSpec.Builder(mContext).setAlias("myKey") |
| * .setSubject(new X500Principal("CN=myKey")).setSerial(BigInteger.valueOf(1337)) |
| * .setStartDate(start.getTime()).setEndDate(end.getTime()).build(); |
| * </pre> |
| */ |
| public final static class Builder { |
| private final Context mContext; |
| |
| private String mKeystoreAlias; |
| |
| private String mKeyType; |
| |
| private int mKeySize = -1; |
| |
| private AlgorithmParameterSpec mSpec; |
| |
| private X500Principal mSubjectDN; |
| |
| private BigInteger mSerialNumber; |
| |
| private Date mStartDate; |
| |
| private Date mEndDate; |
| |
| private int mFlags; |
| |
| private Date mKeyValidityStart; |
| |
| private Date mKeyValidityForOriginationEnd; |
| |
| private Date mKeyValidityForConsumptionEnd; |
| |
| private @KeyStoreKeyProperties.PurposeEnum int mPurposes; |
| |
| private String[] mDigests; |
| |
| private String[] mEncryptionPaddings; |
| |
| private String[] mSignaturePaddings; |
| |
| private String[] mBlockModes; |
| |
| private boolean mRandomizedEncryptionRequired = true; |
| |
| private @KeyStoreKeyProperties.UserAuthenticatorEnum int mUserAuthenticators; |
| |
| private int mUserAuthenticationValidityDurationSeconds = -1; |
| |
| /** |
| * Creates a new instance of the {@code Builder} with the given |
| * {@code context}. The {@code context} passed in may be used to pop up |
| * some UI to ask the user to unlock or initialize the Android KeyStore |
| * facility. |
| */ |
| public Builder(Context context) { |
| if (context == null) { |
| throw new NullPointerException("context == null"); |
| } |
| mContext = context; |
| } |
| |
| /** |
| * Sets the alias to be used to retrieve the key later from a |
| * {@link java.security.KeyStore} instance using the |
| * {@code AndroidKeyStore} provider. |
| */ |
| public Builder setAlias(String alias) { |
| if (alias == null) { |
| throw new NullPointerException("alias == null"); |
| } |
| mKeystoreAlias = alias; |
| return this; |
| } |
| |
| /** |
| * Sets the key type (e.g., EC, RSA) of the keypair to be created. |
| */ |
| public Builder setKeyType(String keyType) throws NoSuchAlgorithmException { |
| if (keyType == null) { |
| throw new NullPointerException("keyType == null"); |
| } else { |
| if (KeyStore.getKeyTypeForAlgorithm(keyType) == -1) { |
| throw new NoSuchAlgorithmException("Unsupported key type: " + keyType); |
| } |
| } |
| mKeyType = keyType; |
| return this; |
| } |
| |
| /** |
| * Sets the key size for the keypair to be created. For instance, for a |
| * key type of RSA this will set the modulus size and for a key type of |
| * EC it will select a curve with a matching field size. |
| */ |
| public Builder setKeySize(int keySize) { |
| if (keySize < 0) { |
| throw new IllegalArgumentException("keySize < 0"); |
| } |
| mKeySize = keySize; |
| return this; |
| } |
| |
| /** |
| * Sets the algorithm-specific key generation parameters. For example, for RSA keys |
| * this may be an instance of {@link java.security.spec.RSAKeyGenParameterSpec}. |
| */ |
| public Builder setAlgorithmParameterSpec(AlgorithmParameterSpec spec) { |
| if (spec == null) { |
| throw new NullPointerException("spec == null"); |
| } |
| mSpec = spec; |
| return this; |
| } |
| |
| /** |
| * Sets the subject used for the self-signed certificate of the |
| * generated key pair. |
| * |
| * <p>The subject must be specified on API Level |
| * {@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1 LOLLIPOP_MR1} and older platforms. On |
| * newer platforms the subject defaults to {@code CN=fake} if not specified. |
| */ |
| public Builder setSubject(X500Principal subject) { |
| if (subject == null) { |
| throw new NullPointerException("subject == null"); |
| } |
| mSubjectDN = subject; |
| return this; |
| } |
| |
| /** |
| * Sets the serial number used for the self-signed certificate of the |
| * generated key pair. |
| * |
| * <p>The serial number must be specified on API Level |
| * {@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1 LOLLIPOP_MR1} and older platforms. On |
| * newer platforms the serial number defaults to {@code 1} if not specified. |
| */ |
| public Builder setSerialNumber(BigInteger serialNumber) { |
| if (serialNumber == null) { |
| throw new NullPointerException("serialNumber == null"); |
| } |
| mSerialNumber = serialNumber; |
| return this; |
| } |
| |
| /** |
| * Sets the start of the validity period for the self-signed certificate |
| * of the generated key pair. |
| * |
| * <p>The date must be specified on API Level |
| * {@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1 LOLLIPOP_MR1} and older platforms. On |
| * newer platforms the date defaults to {@code Jan 1 1970} if not specified. |
| */ |
| public Builder setStartDate(Date startDate) { |
| if (startDate == null) { |
| throw new NullPointerException("startDate == null"); |
| } |
| mStartDate = startDate; |
| return this; |
| } |
| |
| /** |
| * Sets the end of the validity period for the self-signed certificate |
| * of the generated key pair. |
| * |
| * <p>The date must be specified on API Level |
| * {@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1 LOLLIPOP_MR1} and older platforms. On |
| * newer platforms the date defaults to {@code Jan 1 2048} if not specified. |
| */ |
| public Builder setEndDate(Date endDate) { |
| if (endDate == null) { |
| throw new NullPointerException("endDate == null"); |
| } |
| mEndDate = endDate; |
| return this; |
| } |
| |
| /** |
| * Indicates that this key must be encrypted at rest on storage. Note |
| * that enabling this will require that the user enable a strong lock |
| * screen (e.g., PIN, password) before creating or using the generated |
| * key is successful. |
| */ |
| public Builder setEncryptionRequired() { |
| mFlags |= KeyStore.FLAG_ENCRYPTED; |
| return this; |
| } |
| |
| /** |
| * Sets the time instant before which the key is not yet valid. |
| * |
| * <p>By default, the key is valid at any instant. |
| * |
| * @see #setKeyValidityEnd(Date) |
| * |
| * @hide |
| */ |
| public Builder setKeyValidityStart(Date startDate) { |
| mKeyValidityStart = startDate; |
| return this; |
| } |
| |
| /** |
| * Sets the time instant after which the key is no longer valid. |
| * |
| * <p>By default, the key is valid at any instant. |
| * |
| * @see #setKeyValidityStart(Date) |
| * @see #setKeyValidityForConsumptionEnd(Date) |
| * @see #setKeyValidityForOriginationEnd(Date) |
| * |
| * @hide |
| */ |
| public Builder setKeyValidityEnd(Date endDate) { |
| setKeyValidityForOriginationEnd(endDate); |
| setKeyValidityForConsumptionEnd(endDate); |
| return this; |
| } |
| |
| /** |
| * Sets the time instant after which the key is no longer valid for encryption and signing. |
| * |
| * <p>By default, the key is valid at any instant. |
| * |
| * @see #setKeyValidityForConsumptionEnd(Date) |
| * |
| * @hide |
| */ |
| public Builder setKeyValidityForOriginationEnd(Date endDate) { |
| mKeyValidityForOriginationEnd = endDate; |
| return this; |
| } |
| |
| /** |
| * Sets the time instant after which the key is no longer valid for decryption and |
| * verification. |
| * |
| * <p>By default, the key is valid at any instant. |
| * |
| * @see #setKeyValidityForOriginationEnd(Date) |
| * |
| * @hide |
| */ |
| public Builder setKeyValidityForConsumptionEnd(Date endDate) { |
| mKeyValidityForConsumptionEnd = endDate; |
| return this; |
| } |
| |
| /** |
| * Sets the set of purposes for which the key can be used. |
| * |
| * <p>This must be specified for all keys. There is no default. |
| * |
| * @hide |
| */ |
| public Builder setPurposes(@KeyStoreKeyProperties.PurposeEnum int purposes) { |
| mPurposes = purposes; |
| return this; |
| } |
| |
| /** |
| * Sets the set of digests with which the key can be used when signing/verifying. Attempts |
| * to use the key with any other digest will be rejected. |
| * |
| * <p>This must be specified for keys which are used for signing/verification. |
| * |
| * @hide |
| */ |
| public Builder setDigests(String... digests) { |
| mDigests = ArrayUtils.cloneIfNotEmpty(digests); |
| return this; |
| } |
| |
| /** |
| * Sets the set of padding schemes with which the key can be used when |
| * encrypting/decrypting. Attempts to use the key with any other padding scheme will be |
| * rejected. |
| * |
| * <p>This must be specified for keys which are used for encryption/decryption. |
| * |
| * @hide |
| */ |
| public Builder setEncryptionPaddings(String... paddings) { |
| mEncryptionPaddings = ArrayUtils.cloneIfNotEmpty(paddings); |
| return this; |
| } |
| |
| /** |
| * Sets the set of padding schemes with which the key can be used when |
| * signing/verifying. Attempts to use the key with any other padding scheme will be |
| * rejected. |
| * |
| * <p>This must be specified for RSA keys which are used for signing/verification. |
| * |
| * @hide |
| */ |
| public Builder setSignaturePaddings(String... paddings) { |
| mSignaturePaddings = ArrayUtils.cloneIfNotEmpty(paddings); |
| return this; |
| } |
| |
| /** |
| * Sets the set of block modes with which the key can be used when encrypting/decrypting. |
| * Attempts to use the key with any other block modes will be rejected. |
| * |
| * <p>This must be specified for encryption/decryption keys. |
| * |
| * @hide |
| */ |
| public Builder setBlockModes(String... blockModes) { |
| mBlockModes = ArrayUtils.cloneIfNotEmpty(blockModes); |
| return this; |
| } |
| |
| /** |
| * Sets whether encryption using this key must be sufficiently randomized to produce |
| * different ciphertexts for the same plaintext every time. The formal cryptographic |
| * property being required is <em>indistinguishability under chosen-plaintext attack |
| * ({@code IND-CPA})</em>. This property is important because it mitigates several classes |
| * of weaknesses due to which ciphertext may leak information about plaintext. For example, |
| * if a given plaintext always produces the same ciphertext, an attacker may see the |
| * repeated ciphertexts and be able to deduce something about the plaintext. |
| * |
| * <p>By default, {@code IND-CPA} is required. |
| * |
| * <p>When {@code IND-CPA} is required, encryption/decryption transformations which do not |
| * offer {@code IND-CPA}, such as RSA without padding, are prohibited. |
| * |
| * <p>Before disabling this requirement, consider the following approaches instead: |
| * <ul> |
| * <li>If you are using RSA encryption without padding, consider switching to padding |
| * schemes which offer {@code IND-CPA}, such as PKCS#1 or OAEP.</li> |
| * </ul> |
| * |
| * @hide |
| */ |
| public Builder setRandomizedEncryptionRequired(boolean required) { |
| mRandomizedEncryptionRequired = required; |
| return this; |
| } |
| |
| /** |
| * Sets the user authenticators which protect access to this key. The key can only be used |
| * iff the user has authenticated to at least one of these user authenticators. |
| * |
| * <p>By default, the key can be used without user authentication. |
| * |
| * <p>This restriction applies only to private key operations. Public key operations are not |
| * restricted. |
| * |
| * @param userAuthenticators user authenticators or {@code 0} if this key can be accessed |
| * without user authentication. |
| * |
| * @see #setUserAuthenticationValidityDurationSeconds(int) |
| * |
| * @hide |
| */ |
| public Builder setUserAuthenticators( |
| @KeyStoreKeyProperties.UserAuthenticatorEnum int userAuthenticators) { |
| mUserAuthenticators = userAuthenticators; |
| return this; |
| } |
| |
| /** |
| * Sets the duration of time (seconds) for which this key can be used after the user |
| * successfully authenticates to one of the associated user authenticators. |
| * |
| * <p>By default, the user needs to authenticate for every use of the key. |
| * |
| * <p>This restriction applies only to private key operations. Public key operations are not |
| * restricted. |
| * |
| * @param seconds duration in seconds or {@code 0} if the user needs to authenticate for |
| * every use of the key. |
| * |
| * @see #setUserAuthenticators(int) |
| * |
| * @hide |
| */ |
| public Builder setUserAuthenticationValidityDurationSeconds(int seconds) { |
| mUserAuthenticationValidityDurationSeconds = seconds; |
| return this; |
| } |
| |
| /** |
| * Builds the instance of the {@code KeyPairGeneratorSpec}. |
| * |
| * @throws IllegalArgumentException if a required field is missing |
| * @return built instance of {@code KeyPairGeneratorSpec} |
| */ |
| public KeyPairGeneratorSpec build() { |
| return new KeyPairGeneratorSpec(mContext, |
| mKeystoreAlias, |
| mKeyType, |
| mKeySize, |
| mSpec, |
| mSubjectDN, |
| mSerialNumber, |
| mStartDate, |
| mEndDate, |
| mFlags, |
| mKeyValidityStart, |
| mKeyValidityForOriginationEnd, |
| mKeyValidityForConsumptionEnd, |
| mPurposes, |
| mDigests, |
| mEncryptionPaddings, |
| mSignaturePaddings, |
| mBlockModes, |
| mRandomizedEncryptionRequired, |
| mUserAuthenticators, |
| mUserAuthenticationValidityDurationSeconds); |
| } |
| } |
| } |