Updated on 2026-08-14

app/src/main/java/com/tangem/wallet/Digest.java

@@ -0,0 +1,114 @@
+package com.tangem.wallet;
+
+/**
+ * Created by Ilia on 18.12.2017.
+ */
+
+public interface Digest{
+
+    /**
+     * Insert one more input data byte.
+     *
+     * @param in   the input byte
+     */
+    void update(byte in);
+
+    /**
+     * Insert some more bytes.
+     *
+     * @param inbuf   the data bytes
+     */
+    void update(byte[] inbuf);
+
+    /**
+     * Insert some more bytes.
+     *
+     * @param inbuf   the data buffer
+     * @param off     the data offset in {@code inbuf}
+     * @param len     the data length (in bytes)
+     */
+    void update(byte[] inbuf, int off, int len);
+
+    /**
+     * Finalize the current hash computation and return the hash value
+     * in a newly-allocated array. The object is resetted.
+     *
+     * @return  the hash output
+     */
+    byte[] digest();
+
+    /**
+     * Input some bytes, then finalize the current hash computation
+     * and return the hash value in a newly-allocated array. The object
+     * is resetted.
+     *
+     * @param inbuf   the input data
+     * @return  the hash output
+     */
+    byte[] digest(byte[] inbuf);
+
+    /**
+     * Finalize the current hash computation and store the hash value
+     * in the provided output buffer. The {@code len} parameter
+     * contains the maximum number of bytes that should be written;
+     * no more bytes than the natural hash function output length will
+     * be produced. If {@code len} is smaller than the natural
+     * hash output length, the hash output is truncated to its first
+     * {@code len} bytes. The object is resetted.
+     *
+     * @param outbuf   the output buffer
+     * @param off      the output offset within {@code outbuf}
+     * @param len      the requested hash output length (in bytes)
+     * @return  the number of bytes actually written in {@code outbuf}
+     */
+    int digest(byte[] outbuf, int off, int len);
+
+    /**
+     * Get the natural hash function output length (in bytes).
+     *
+     * @return  the digest output length (in bytes)
+     */
+    int getDigestLength();
+
+    /**
+     * Reset the object: this makes it suitable for a new hash
+     * computation. The current computation, if any, is discarded.
+     */
+    void reset();
+
+    /**
+     * Clone the current state. The returned object evolves independantly
+     * of this object.
+     *
+     * @return  the clone
+     */
+    Digest copy();
+
+    /**
+     * <p>Return the "block length" for the hash function. This
+     * value is naturally defined for iterated hash functions
+     * (Merkle-Damgard). It is used in HMAC (that's what the
+     * <a href="http://tools.ietf.org/html/rfc2104">HMAC specification</a>
+     * names the "{@code B}" parameter).</p>
+     *
+     * <p>If the function is "block-less" then this function may
+     * return {@code -n} where {@code n} is an integer such that the
+     * block length for HMAC ("{@code B}") will be inferred from the
+     * key length, by selecting the smallest multiple of {@code n}
+     * which is no smaller than the key length. For instance, for
+     * the Fugue-xxx hash functions, this function returns -4: the
+     * virtual block length B is the HMAC key length, rounded up to
+     * the next multiple of 4.</p>
+     *
+     * @return  the internal block length (in bytes), or {@code -n}
+     */
+    int getBlockLength();
+
+    /**
+     * <p>Get the display name for this function (e.g. {@code "SHA-1"}
+     * for SHA-1).</p>
+     *
+     * @see Object
+     */
+    String toString();
+}