author | jnimeh |
Wed, 30 May 2018 11:36:46 -0700 | |
branch | JDK-8145252-TLS13-branch |
changeset 56637 | d66751750b72 |
parent 56542 | 56aaa6cb3693 |
child 56648 | 88da002507ab |
permissions | -rwxr-xr-x |
56542 | 1 |
/* |
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* Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package sun.security.ssl; |
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import java.security.NoSuchAlgorithmException; |
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import java.security.InvalidKeyException; |
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import javax.crypto.Mac; |
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import javax.crypto.SecretKey; |
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import javax.crypto.ShortBufferException; |
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import javax.crypto.spec.SecretKeySpec; |
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import java.util.Objects; |
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/** |
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* An implementation of the HKDF key derivation algorithm outlined in RFC 5869, |
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* specific to the needs of TLS 1.3 key derivation in JSSE. This is not a |
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* general purpose HKDF implementation and is suited only to single-key output |
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* derivations. |
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* |
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* HKDF objects are created by specifying a message digest algorithm. That |
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* digest algorithm will be used by the HMAC function as part of the HKDF |
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* derivation process. |
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*/ |
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class HKDF { |
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private final String hmacAlg; |
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private final Mac hmacObj; |
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private final int hmacLen; |
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/** |
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* Create an HDKF object, specifying the underlying message digest |
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* algorithm. |
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* |
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* @param hashAlg a standard name corresponding to a supported message |
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* digest algorithm. |
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* |
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* @throws NoSuchAlgorithmException if that message digest algorithm does |
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* not have an HMAC variant supported on any available provider. |
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*/ |
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HKDF(String hashAlg) throws NoSuchAlgorithmException { |
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Objects.requireNonNull(hashAlg, |
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"Must provide underlying HKDF Digest algorithm."); |
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hmacAlg = "Hmac" + hashAlg.replace("-", ""); |
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hmacObj = Mac.getInstance(hmacAlg); |
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hmacLen = hmacObj.getMacLength(); |
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} |
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/** |
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* Perform the HMAC-Extract derivation. |
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* |
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* @param salt a salt value, implemented as a {@code SecretKey}. A |
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* {@code null} value is allowed, which will internally use an array of |
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* zero bytes the same size as the underlying hash output length. |
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* @param inputKey the input keying material provided as a |
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* {@code SecretKey}. |
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* @param keyAlg the algorithm name assigned to the resulting |
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* {@code SecretKey} object. |
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* |
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* @return a {@code SecretKey} that is the result of the HKDF extract |
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* operation. |
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* |
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* @throws InvalidKeyException if the {@code salt} parameter cannot be |
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* used to initialize the underlying HMAC. |
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*/ |
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SecretKey extract(SecretKey salt, SecretKey inputKey, String keyAlg) |
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throws InvalidKeyException { |
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if (salt == null) { |
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salt = new SecretKeySpec(new byte[hmacLen], "HKDF-Salt"); |
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} |
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hmacObj.init(salt); |
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return new SecretKeySpec(hmacObj.doFinal(inputKey.getEncoded()), |
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keyAlg); |
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} |
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/** |
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* Perform the HMAC-Extract derivation. |
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* |
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* @param salt a salt value as cleartext bytes. A {@code null} value is |
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* allowed, which will internally use an array of zero bytes the same |
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* size as the underlying hash output length. |
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* @param inputKey the input keying material provided as a |
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* {@code SecretKey}. |
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* @param keyAlg the algorithm name assigned to the resulting |
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* {@code SecretKey} object. |
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* |
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* @return a {@code SecretKey} that is the result of the HKDF extract |
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* operation. |
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* |
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* @throws InvalidKeyException if the {@code salt} parameter cannot be |
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* used to initialize the underlying HMAC. |
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*/ |
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SecretKey extract(byte[] salt, SecretKey inputKey, String keyAlg) |
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throws InvalidKeyException { |
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if (salt == null) { |
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salt = new byte[hmacLen]; |
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} |
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return extract(new SecretKeySpec(salt, "HKDF-Salt"), inputKey, keyAlg); |
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} |
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/** |
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* Perform the HKDF-Expand derivation for a single-key output. |
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* |
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* @param pseudoRandKey the pseudo random key (PRK). |
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* @param info optional context-specific info. A {@code null} value is |
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* allowed in which case a zero-length byte array will be used. |
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* @param outLen the length of the resulting {@code SecretKey} |
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* @param keyAlg the algorithm name applied to the resulting |
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* {@code SecretKey} |
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* |
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* @return the resulting key derivation as a {@code SecretKey} object |
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* |
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* @throws InvalidKeyException if the underlying HMAC operation cannot |
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* be initialized using the provided {@code pseudoRandKey} object. |
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*/ |
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SecretKey expand(SecretKey pseudoRandKey, byte[] info, int outLen, |
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String keyAlg) throws InvalidKeyException { |
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byte[] kdfOutput; |
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// Calculate the number of rounds of HMAC that are needed to |
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// meet the requested data. Then set up the buffers we will need. |
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Objects.requireNonNull(pseudoRandKey, "A null PRK is not allowed."); |
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56637
d66751750b72
Add bounds check for output length in HKDF expand operation
jnimeh
parents:
56542
diff
changeset
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d66751750b72
Add bounds check for output length in HKDF expand operation
jnimeh
parents:
56542
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changeset
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// Output from the expand operation must be <= 255 * hmac length |
d66751750b72
Add bounds check for output length in HKDF expand operation
jnimeh
parents:
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if (outLen > 255 * hmacLen) { |
d66751750b72
Add bounds check for output length in HKDF expand operation
jnimeh
parents:
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throw new IllegalArgumentException("Requested output length " + |
d66751750b72
Add bounds check for output length in HKDF expand operation
jnimeh
parents:
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"exceeds maximum length allowed for HKDF expansion"); |
d66751750b72
Add bounds check for output length in HKDF expand operation
jnimeh
parents:
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} |
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hmacObj.init(pseudoRandKey); |
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if (info == null) { |
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info = new byte[0]; |
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} |
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int rounds = (outLen + hmacLen - 1) / hmacLen; |
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kdfOutput = new byte[rounds * hmacLen]; |
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int offset = 0; |
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int tLength = 0; |
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for (int i = 0; i < rounds ; i++) { |
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// Calculate this round |
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try { |
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// Add T(i). This will be an empty string on the first |
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// iteration since tLength starts at zero. After the first |
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// iteration, tLength is changed to the HMAC length for the |
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// rest of the loop. |
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hmacObj.update(kdfOutput, |
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Math.max(0, offset - hmacLen), tLength); |
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hmacObj.update(info); // Add info |
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hmacObj.update((byte)(i + 1)); // Add round number |
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hmacObj.doFinal(kdfOutput, offset); |
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tLength = hmacLen; |
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offset += hmacLen; // For next iteration |
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} catch (ShortBufferException sbe) { |
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// This really shouldn't happen given that we've |
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// sized the buffers to their largest possible size up-front, |
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// but just in case... |
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throw new RuntimeException(sbe); |
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} |
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} |
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return new SecretKeySpec(kdfOutput, 0, outLen, keyAlg); |
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} |
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/** |
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* Perform the HKDF Extract-then-Expand operation. |
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* |
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* @param inputKey the input keying material provided as a |
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* {@code SecretKey}. |
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* @param salt a salt value, implemented as a {@code SecretKey}. A |
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* {@code null} value is allowed, which will internally use an array of |
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* zero bytes the same size as the underlying hash output length. |
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* @param info optional context-specific info. A {@code null} value is |
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* allowed in which case a zero-length byte array will be used. |
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* @param outLen the length of the resulting {@code SecretKey} |
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* @param keyAlg the algorithm name applied to the resulting |
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* {@code SecretKey} |
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* |
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* @return the resulting derivation stored in a {@code SecretKey} object. |
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* |
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* @throws InvalidKeyException if initialization of the underlying HMAC |
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* process fails with the salt during the extract phase, or with the |
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* resulting PRK during the expand phase. |
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*/ |
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SecretKey extractExpand(SecretKey inputKey, SecretKey salt, byte[] info, |
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int outLen, String keyAlg) throws InvalidKeyException { |
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SecretKey prk = extract(salt, inputKey, "HKDF-PRK"); |
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return expand(prk, info, outLen, keyAlg); |
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} |
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/** |
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* Perform the HKDF Extract-then-Expand operation. |
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* |
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* @param inputKey the input keying material provided as a |
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* {@code SecretKey}. |
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* @param salt a salt value as cleartext bytes. A {@code null} value is |
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* allowed, which will internally use an array of zero bytes the same |
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* size as the underlying hash output length. |
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* @param info optional context-specific info. A {@code null} value is |
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* allowed in which case a zero-length byte array will be used. |
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* @param outLen the length of the resulting {@code SecretKey} |
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* @param keyAlg the algorithm name applied to the resulting |
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* {@code SecretKey} |
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* |
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* @return the resulting derivation stored in a {@code SecretKey} object. |
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* |
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* @throws InvalidKeyException if initialization of the underlying HMAC |
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* process fails with the salt during the extract phase, or with the |
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* resulting PRK during the expand phase. |
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*/ |
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SecretKey extractExpand(SecretKey inputKey, byte[] salt, byte[] info, |
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int outLen, String keyAlg) throws InvalidKeyException { |
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byte[] saltBytes = (salt != null) ? salt : new byte[hmacLen]; |
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return extractExpand(inputKey, |
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new SecretKeySpec(saltBytes, "HKDF-PRK"), info, outLen, keyAlg); |
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} |
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} |