Add base32 decoder.

Thanks to GitHub user 'markov':
https://gist.github.com/markov/5206312

4 files changed, 672 insertions, 29 deletions

diff --git a/util/build.gradle b/util/build.gradle
index 394342ba..8812b1e9 100644
--- a/util/build.gradle
+++ b/util/build.gradle
@@ -41,7 +41,6 @@ dependencies {
     implementation group: 'org.bouncycastle', name: 'bcprov-jdk15on', version: '1.64'
     implementation group: 'org.xerial', name: 'sqlite-jdbc', version: '3.28.0'
     implementation group: 'org.apache.commons', name: 'commons-compress', version: '1.20'
-    implementation("com.msiops.ground:ground-crockford32:0.1")
 
     testImplementation group: 'junit', name: 'junit', version: '4.12'
     testImplementation 'org.jetbrains.kotlin:kotlin-test-junit:1.3.50'
diff --git a/util/src/main/kotlin/CrockfordBase32.java b/util/src/main/kotlin/CrockfordBase32.java
new file mode 100644
index 00000000..ba5ec8ff
--- /dev/null
+++ b/util/src/main/kotlin/CrockfordBase32.java
@@ -0,0 +1,655 @@
+import java.nio.charset.Charset;
+
+/**
+ * <p>Provides Base32 encoding and decoding as defined by <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a>.
+ * However it uses a custom alphabet first coined by Douglas Crockford. Only addition to the alphabet is that 'u' and
+ * 'U' characters decode as if they were 'V' to improve mistakes by human input.<p/>
+ * <p>
+ * This class operates directly on byte streams, and not character streams.
+ * </p>
+ *
+ * @version $Id: Base32.java 1382498 2012-09-09 13:41:55Z sebb $
+ * @see <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a>
+ * @see <a href="http://www.crockford.com/wrmg/base32.html">Douglas Crockford's Base32 Encoding</a>
+ * @since 1.5
+ */
+public class CrockfordBase32 {
+
+    /**
+     * Mask used to extract 8 bits, used in decoding bytes
+     */
+    protected static final int MASK_8BITS = 0xff;
+    private static final Charset UTF8 = Charset.forName("UTF-8");
+    private static final int DEFAULT_BUFFER_RESIZE_FACTOR = 2;
+    /**
+     * Defines the default buffer size - currently {@value}
+     * - must be large enough for at least one encoded block+separator
+     */
+    private static final int DEFAULT_BUFFER_SIZE = 8192;
+    /**
+     * Mask used to extract 5 bits, used when encoding Base32 bytes
+     */
+    private static final int MASK_5BITS = 0x1f;
+    /**
+     * BASE32 characters are 5 bits in length.
+     * They are formed by taking a block of five octets to form a 40-bit string,
+     * which is converted into eight BASE32 characters.
+     */
+    private static final int BITS_PER_ENCODED_BYTE = 5;
+    private static final int BYTES_PER_ENCODED_BLOCK = 8;
+    private static final int BYTES_PER_UNENCODED_BLOCK = 5;
+    private static final byte PAD = '=';
+    /**
+     * This array is a lookup table that translates 5-bit positive integer index values into their "Base32 Alphabet"
+     * equivalents as specified in Table 3 of RFC 2045.
+     */
+    private static final byte[] ENCODE_TABLE = {
+            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'M',
+            'N', 'P', 'Q', 'R', 'S', 'T', 'V', 'W', 'X', 'Y', 'Z'
+    };
+    /**
+     * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
+     * <code>decodeSize = {@link #BYTES_PER_ENCODED_BLOCK} - 1 + lineSeparator.length;</code>
+     */
+    private final int decodeSize;
+    /**
+     * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
+     * <code>encodeSize = {@link #BYTES_PER_ENCODED_BLOCK} + lineSeparator.length;</code>
+     */
+    private final int encodeSize;
+    /**
+     * Wheather this encoder should use a padding character at the end of encoded Strings.
+     */
+    private final boolean usePaddingCharacter;
+    /**
+     * Buffer for streaming.
+     */
+    protected byte[] buffer;
+    /**
+     * Position where next character should be written in the buffer.
+     */
+    protected int pos;
+    /**
+     * Boolean flag to indicate the EOF has been reached. Once EOF has been reached, this object becomes useless,
+     * and must be thrown away.
+     */
+    protected boolean eof;
+    /**
+     * Writes to the buffer only occur after every 3/5 reads when encoding, and every 4/8 reads when decoding.
+     * This variable helps track that.
+     */
+    protected int modulus;
+    /**
+     * Place holder for the bytes we're dealing with for our based logic.
+     * Bitwise operations store and extract the encoding or decoding from this variable.
+     */
+    private long bitWorkArea;
+
+    public CrockfordBase32() {
+        this(false);
+    }
+
+    /**
+     * Creates a Base32 codec used for decoding and encoding.
+     * <p>
+     * When encoding the line length is 0 (no chunking).
+     * </p>
+     */
+    public CrockfordBase32(boolean usePaddingCharacter) {
+        this.usePaddingCharacter = usePaddingCharacter;
+        this.encodeSize = BYTES_PER_ENCODED_BLOCK;
+        this.decodeSize = this.encodeSize - 1;
+    }
+
+    private static byte decode(byte octet) {
+        switch (octet) {
+            case '0':
+            case 'O':
+            case 'o':
+                return 0;
+
+            case '1':
+            case 'I':
+            case 'i':
+            case 'L':
+            case 'l':
+                return 1;
+
+            case '2':
+                return 2;
+            case '3':
+                return 3;
+            case '4':
+                return 4;
+            case '5':
+                return 5;
+            case '6':
+                return 6;
+            case '7':
+                return 7;
+            case '8':
+                return 8;
+            case '9':
+                return 9;
+
+            case 'A':
+            case 'a':
+                return 10;
+
+            case 'B':
+            case 'b':
+                return 11;
+
+            case 'C':
+            case 'c':
+                return 12;
+
+            case 'D':
+            case 'd':
+                return 13;
+
+            case 'E':
+            case 'e':
+                return 14;
+
+            case 'F':
+            case 'f':
+                return 15;
+
+            case 'G':
+            case 'g':
+                return 16;
+
+            case 'H':
+            case 'h':
+                return 17;
+
+            case 'J':
+            case 'j':
+                return 18;
+
+            case 'K':
+            case 'k':
+                return 19;
+
+            case 'M':
+            case 'm':
+                return 20;
+
+            case 'N':
+            case 'n':
+                return 21;
+
+            case 'P':
+            case 'p':
+                return 22;
+
+            case 'Q':
+            case 'q':
+                return 23;
+
+            case 'R':
+            case 'r':
+                return 24;
+
+            case 'S':
+            case 's':
+                return 25;
+
+            case 'T':
+            case 't':
+                return 26;
+
+            case 'U':
+            case 'u':
+            case 'V':
+            case 'v':
+                return 27;
+
+            case 'W':
+            case 'w':
+                return 28;
+
+            case 'X':
+            case 'x':
+                return 29;
+
+            case 'Y':
+            case 'y':
+                return 30;
+
+            case 'Z':
+            case 'z':
+                return 31;
+
+            default:
+                return -1;
+        }
+    }
+
+    /**
+     * Checks if a byte value is whitespace or not.
+     * Whitespace is taken to mean: space, tab, CR, LF
+     *
+     * @param byteToCheck the byte to check
+     * @return true if byte is whitespace, false otherwise
+     */
+    protected static boolean isWhiteSpace(byte byteToCheck) {
+        switch (byteToCheck) {
+            case ' ':
+            case '\n':
+            case '\r':
+            case '\t':
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    /**
+     * Tests a given String to see if it contains only valid characters within the alphabet.
+     * The method treats whitespace and PAD as valid.
+     *
+     * @param base32 String to test
+     * @return <code>true</code> if all characters in the String are valid characters in the alphabet or if
+     *         the String is empty; <code>false</code>, otherwise
+     * @see #isInAlphabet(byte[], boolean)
+     */
+    public static boolean isInAlphabet(String base32) {
+        return isInAlphabet(base32.getBytes(UTF8), true);
+    }
+
+    /**
+     * Tests a given byte array to see if it contains only valid characters within the alphabet.
+     * The method optionally treats whitespace and pad as valid.
+     *
+     * @param arrayOctet byte array to test
+     * @param allowWSPad if <code>true</code>, then whitespace and PAD are also allowed
+     * @return <code>true</code> if all bytes are valid characters in the alphabet or if the byte array is empty;
+     *         <code>false</code>, otherwise
+     */
+    public static boolean isInAlphabet(byte[] arrayOctet, boolean allowWSPad) {
+        for (int i = 0; i < arrayOctet.length; i++) {
+            if (!isInAlphabet(arrayOctet[i]) &&
+                    (!allowWSPad || (arrayOctet[i] != PAD) && !isWhiteSpace(arrayOctet[i]))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Returns whether or not the <code>octet</code> is in the Base32 alphabet.
+     *
+     * @param octet The value to test
+     * @return <code>true</code> if the value is defined in the the Base32 alphabet <code>false</code> otherwise.
+     */
+    public static boolean isInAlphabet(byte octet) {
+        return decode(octet) != -1;
+    }
+
+    /**
+     * Returns the amount of buffered data available for reading.
+     *
+     * @return The amount of buffered data available for reading.
+     */
+    int available() {  // package protected for access from I/O streams
+        return buffer != null ? pos : 0;
+    }
+
+    /**
+     * Increases our buffer by the {@link #DEFAULT_BUFFER_RESIZE_FACTOR}.
+     */
+    private void resizeBuffer() {
+        if (buffer == null) {
+            buffer = new byte[DEFAULT_BUFFER_SIZE];
+            pos = 0;
+        } else {
+            byte[] b = new byte[buffer.length * DEFAULT_BUFFER_RESIZE_FACTOR];
+            System.arraycopy(buffer, 0, b, 0, buffer.length);
+            buffer = b;
+        }
+    }
+
+    /**
+     * Ensure that the buffer has room for <code>size</code> bytes
+     *
+     * @param size minimum spare space required
+     */
+    protected void ensureBufferSize(int size) {
+        if ((buffer == null) || (buffer.length < pos + size)) {
+            resizeBuffer();
+        }
+    }
+
+    /**
+     * Extracts buffered data into the provided byte[] array, starting at position bPos,
+     * up to a maximum of bAvail bytes. Returns how many bytes were actually extracted.
+     *
+     * @param b byte[] array to extract the buffered data into.
+     * @return The number of bytes successfully extracted into the provided byte[] array.
+     */
+    int readResults(byte[] b) {  // package protected for access from I/O streams
+        if (buffer != null) {
+            int len = available();
+            System.arraycopy(buffer, 0, b, 0, len);
+            buffer = null; // so hasData() will return false, and this method can return -1
+            return len;
+        }
+        return eof ? -1 : 0;
+    }
+
+    /**
+     * Resets this object to its initial newly constructed state.
+     */
+    private void reset() {
+        buffer = null;
+        pos = 0;
+        modulus = 0;
+        eof = false;
+    }
+
+    /**
+     * Encodes a String containing characters in the Base32 alphabet.
+     *
+     * @param pArray A String containing Base32 character data
+     * @return A String containing only Base32 character data
+     */
+    public String encodeToString(String pArray) {
+        return encodeToString(pArray.getBytes(UTF8));
+    }
+
+    /**
+     * Encodes a byte[] containing binary data, into a String containing characters in the Base-N alphabet.
+     *
+     * @param pArray a byte array containing binary data
+     * @return A String containing only Base32 character data
+     */
+    public String encodeToString(byte[] pArray) {
+        return new String(encode(pArray), UTF8);
+    }
+
+    /**
+     * Encodes a String containing characters in the Base32 alphabet.
+     *
+     * @param pArray A String containing Base32 character data
+     * @return A UTF-8 decoded String
+     */
+    public String decodeToString(String pArray) {
+        return decodeToString(pArray.getBytes(UTF8));
+    }
+
+    /**
+     * Decodes a byte[] containing binary data, into a String containing UTF-8 decoded String.
+     *
+     * @param pArray a byte array containing binary data
+     * @return A UTF-8 decoded String
+     */
+    public String decodeToString(byte[] pArray) {
+        return new String(decode(pArray), UTF8);
+    }
+
+    /**
+     * Decodes a String containing characters in the Base-N alphabet.
+     *
+     * @param pArray A String containing Base-N character data
+     * @return a byte array containing binary data
+     */
+    public byte[] decode(String pArray) {
+        return decode(pArray.getBytes(UTF8));
+    }
+
+    /**
+     * Encodes a String containing characters in the Base32 alphabet.
+     *
+     * @param pArray A String containing Base-N character data
+     * @return a byte array containing binary data
+     */
+    public byte[] encode(String pArray) {
+        return encode(pArray.getBytes(UTF8));
+    }
+
+    /**
+     * Decodes a byte[] containing characters in the Base-N alphabet.
+     *
+     * @param pArray A byte array containing Base-N character data
+     * @return a byte array containing binary data
+     */
+    public byte[] decode(byte[] pArray) {
+        reset();
+        if (pArray == null || pArray.length == 0) {
+            return pArray;
+        }
+        decode(pArray, 0, pArray.length);
+        decode(pArray, 0, -1); // Notify decoder of EOF.
+        byte[] result = new byte[pos];
+        readResults(result);
+        return result;
+    }
+
+    // The static final fields above are used for the original static byte[] methods on Base32.
+    // The private member fields below are used with the new streaming approach, which requires
+    // some state be preserved between calls of encode() and decode().
+
+    /**
+     * Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
+     *
+     * @param pArray a byte array containing binary data
+     * @return A byte array containing only the basen alphabetic character data
+     */
+    public byte[] encode(byte[] pArray) {
+        reset();
+        if (pArray == null || pArray.length == 0) {
+            return pArray;
+        }
+        encode(pArray, 0, pArray.length);
+        encode(pArray, 0, -1); // Notify encoder of EOF.
+        byte[] buf = new byte[pos];
+        readResults(buf);
+        return buf;
+    }
+
+    /**
+     * Calculates the amount of space needed to encode the supplied array.
+     *
+     * @param pArray byte[] array which will later be encoded
+     * @return amount of space needed to encoded the supplied array.
+     *         Returns a long since a max-len array will require > Integer.MAX_VALUE
+     */
+    public long getEncodedLength(byte[] pArray) {
+        // Calculate non-chunked size - rounded up to allow for padding
+        // cast to long is needed to avoid possibility of overflow
+        long len = ((pArray.length + BYTES_PER_UNENCODED_BLOCK - 1) / BYTES_PER_UNENCODED_BLOCK) * (long) BYTES_PER_ENCODED_BLOCK;
+        return len;
+    }
+
+    /**
+     * <p>
+     * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once
+     * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1"
+     * call is not necessary when decoding, but it doesn't hurt, either.
+     * </p>
+     * <p>
+     * Ignores all non-Base32 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are
+     * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in,
+     * garbage-out philosophy: it will not check the provided data for validity.
+     * </p>
+     *
+     * @param in      byte[] array of ascii data to Base32 decode.
+     * @param inPos   Position to start reading data from.
+     * @param inAvail Amount of bytes available from input for encoding.
+     *                <p/>
+     *                Output is written to {@link #buffer} as 8-bit octets, using {@link #pos} as the buffer position
+     */
+    void decode(byte[] in, int inPos, int inAvail) { // package protected for access from I/O streams
+        if (eof) {
+            return;
+        }
+        if (inAvail < 0) {
+            eof = true;
+        }
+        for (int i = 0; i < inAvail; i++) {
+            byte b = in[inPos++];
+            if (b == PAD) {
+                // We're done.
+                eof = true;
+                break;
+            } else {
+                ensureBufferSize(decodeSize);
+                if (isInAlphabet(b)) {
+                    int result = decode(b);
+                    modulus = (modulus + 1) % BYTES_PER_ENCODED_BLOCK;
+                    bitWorkArea = (bitWorkArea << BITS_PER_ENCODED_BYTE) + result; // collect decoded bytes
+                    if (modulus == 0) { // we can output the 5 bytes
+                        buffer[pos++] = (byte) ((bitWorkArea >> 32) & MASK_8BITS);
+                        buffer[pos++] = (byte) ((bitWorkArea >> 24) & MASK_8BITS);
+                        buffer[pos++] = (byte) ((bitWorkArea >> 16) & MASK_8BITS);
+                        buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS);
+                        buffer[pos++] = (byte) (bitWorkArea & MASK_8BITS);
+                    }
+                }
+            }
+        }
+
+        // Two forms of EOF as far as Base32 decoder is concerned: actual
+        // EOF (-1) and first time '=' character is encountered in stream.
+        // This approach makes the '=' padding characters completely optional.
+        if (eof && modulus >= 2) { // if modulus < 2, nothing to do
+            ensureBufferSize(decodeSize);
+
+            //  we ignore partial bytes, i.e. only multiples of 8 count
+            switch (modulus) {
+                case 2: // 10 bits, drop 2 and output one byte
+                    buffer[pos++] = (byte) ((bitWorkArea >> 2) & MASK_8BITS);
+                    break;
+                case 3: // 15 bits, drop 7 and output 1 byte
+                    buffer[pos++] = (byte) ((bitWorkArea >> 7) & MASK_8BITS);
+                    break;
+                case 4: // 20 bits = 2*8 + 4
+                    bitWorkArea = bitWorkArea >> 4; // drop 4 bits
+                    buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS);
+                    break;
+                case 5: // 25bits = 3*8 + 1
+                    bitWorkArea = bitWorkArea >> 1;
+                    buffer[pos++] = (byte) ((bitWorkArea >> 16) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS);
+                    break;
+                case 6: // 30bits = 3*8 + 6
+                    bitWorkArea = bitWorkArea >> 6;
+                    buffer[pos++] = (byte) ((bitWorkArea >> 16) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS);
+                    break;
+                case 7: // 35 = 4*8 +3
+                    bitWorkArea = bitWorkArea >> 3;
+                    buffer[pos++] = (byte) ((bitWorkArea >> 24) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea >> 16) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS);
+                    buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS);
+                    break;
+            }
+        }
+    }
+
+    /**
+     * <p>
+     * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with
+     * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last
+     * remaining bytes (if not multiple of 5).
+     * </p>
+     *
+     * @param in      byte[] array of binary data to Base32 encode.
+     * @param inPos   Position to start reading data from.
+     * @param inAvail Amount of bytes available from input for encoding.
+     */
+    void encode(byte[] in, int inPos, int inAvail) { // package protected for access from I/O streams
+        if (eof) {
+            return;
+        }
+        // inAvail < 0 is how we're informed of EOF in the underlying data we're
+        // encoding.
+        if (inAvail < 0) {
+            eof = true;
+            if (0 == modulus) {
+                return; // no leftovers to process
+            }
+            ensureBufferSize(encodeSize);
+            int savedPos = pos;
+            switch (modulus) { // % 5
+                case 1: // Only 1 octet; take top 5 bits then remainder
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 3) & MASK_5BITS]; // 8-1*5 = 3
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea << 2) & MASK_5BITS]; // 5-3=2
+                    if (usePaddingCharacter) {
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                    }
+                    break;
+
+                case 2: // 2 octets = 16 bits to use
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 11) & MASK_5BITS]; // 16-1*5 = 11
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 6) & MASK_5BITS]; // 16-2*5 = 6
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 1) & MASK_5BITS]; // 16-3*5 = 1
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea << 4) & MASK_5BITS]; // 5-1 = 4
+                    if (usePaddingCharacter) {
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                    }
+                    break;
+                case 3: // 3 octets = 24 bits to use
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 19) & MASK_5BITS]; // 24-1*5 = 19
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 14) & MASK_5BITS]; // 24-2*5 = 14
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 9) & MASK_5BITS]; // 24-3*5 = 9
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 4) & MASK_5BITS]; // 24-4*5 = 4
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea << 1) & MASK_5BITS]; // 5-4 = 1
+                    if (usePaddingCharacter) {
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                        buffer[pos++] = PAD;
+                    }
+                    break;
+                case 4: // 4 octets = 32 bits to use
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 27) & MASK_5BITS]; // 32-1*5 = 27
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 22) & MASK_5BITS]; // 32-2*5 = 22
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 17) & MASK_5BITS]; // 32-3*5 = 17
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 12) & MASK_5BITS]; // 32-4*5 = 12
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 7) & MASK_5BITS]; // 32-5*5 =  7
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 2) & MASK_5BITS]; // 32-6*5 =  2
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea << 3) & MASK_5BITS]; // 5-2 = 3
+                    if (usePaddingCharacter) {
+                        buffer[pos++] = PAD;
+                    }
+                    break;
+            }
+        } else {
+            for (int i = 0; i < inAvail; i++) {
+                ensureBufferSize(encodeSize);
+                modulus = (modulus + 1) % BYTES_PER_UNENCODED_BLOCK;
+                int b = in[inPos++];
+                if (b < 0) {
+                    b += 256;
+                }
+                bitWorkArea = (bitWorkArea << 8) + b; // BITS_PER_BYTE
+                if (0 == modulus) { // we have enough bytes to create our output
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 35) & MASK_5BITS];
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 30) & MASK_5BITS];
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 25) & MASK_5BITS];
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 20) & MASK_5BITS];
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 15) & MASK_5BITS];
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 10) & MASK_5BITS];
+                    buffer[pos++] = ENCODE_TABLE[(int) (bitWorkArea >> 5) & MASK_5BITS];
+                    buffer[pos++] = ENCODE_TABLE[(int) bitWorkArea & MASK_5BITS];
+                }
+            }
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/util/src/main/kotlin/strings.kt b/util/src/main/kotlin/strings.kt
index 0092e633..d57b53ab 100644
--- a/util/src/main/kotlin/strings.kt
+++ b/util/src/main/kotlin/strings.kt
@@ -2,8 +2,6 @@ package tech.libeufin.util
 import org.apache.commons.codec.binary.Base32
 import java.math.BigInteger
 import java.util.*
-import com.msiops.ground.crockford32.Crockford32
-
 
 fun ByteArray.toHexString() : String {
     return this.joinToString("") {
@@ -43,26 +41,6 @@ fun base64ToBytes(encoding: String): ByteArray {
     return Base64.getDecoder().decode(encoding)
 }
 
-/**
- * Crockford's base32 decoding.
- */
-fun base32ToBytes(encoding: String): ByteArray {
-    val i: BigInteger = Crockford32.decode(encoding)
-    if ((i.bitLength() % 4) != 0) {
-        logger.debug("No extra 4-bits element added (bitLength: ${i.bitLength()})")
-        return i.toByteArray()
-    }
-    val extraByteBlob = i.toByteArray()
-    return Arrays.copyOfRange(extraByteBlob, 1, extraByteBlob.size)
-}
-
-/**
- * Crockford's base32 encoding.
- */
-fun bytesToBase32(bytes: ByteArray): String {
-    return Crockford32.encode(BigInteger(bytes))
-}
-
 fun BigInteger.toUnsignedHexString(): String {
     val signedValue = this.toByteArray()
     require(this.signum() > 0) { "number must be positive" }
diff --git a/util/src/test/kotlin/CryptoUtilTest.kt b/util/src/test/kotlin/CryptoUtilTest.kt
index e3d27ed0..2ef9f823 100644
--- a/util/src/test/kotlin/CryptoUtilTest.kt
+++ b/util/src/test/kotlin/CryptoUtilTest.kt
@@ -22,10 +22,8 @@ import org.bouncycastle.asn1.x509.AlgorithmIdentifier
 import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo
 import org.junit.Test
 import tech.libeufin.util.*
-import java.math.BigInteger
 import java.security.KeyFactory
 import java.security.KeyPairGenerator
-import java.security.Security
 import java.security.interfaces.RSAPrivateCrtKey
 import java.security.spec.KeySpec
 import java.security.spec.X509EncodedKeySpec
@@ -146,11 +144,14 @@ class CryptoUtilTest {
 
     @Test
     fun importEdDSAPublicKeyTest() {
+        val decoder = CrockfordBase32()
         val givenEnc = "XZH3P6NF9DSG3BH0C082X38N2RVK1RV2H24KF76028QBKDM24BCG"
         // import a public key
-        val spki = SubjectPublicKeyInfo(AlgorithmIdentifier(
-            EdECObjectIdentifiers.id_Ed25519),
-            base32ToBytes(givenEnc)
+        val spki = SubjectPublicKeyInfo(
+            AlgorithmIdentifier(
+                EdECObjectIdentifiers.id_Ed25519
+            ),
+            decoder.decode(givenEnc.toByteArray(Charsets.UTF_8))
         )
         val ks: KeySpec = X509EncodedKeySpec(spki.encoded)
         val kpg = KeyFactory.getInstance(
@@ -159,4 +160,14 @@ class CryptoUtilTest {
         )
         kpg.generatePublic(ks)
     }
-}
\ No newline at end of file
+
+    @Test
+    // from Crockford32 encoding to binary.
+    fun base32ToBytesTest() {
+        val decoder = CrockfordBase32()
+        // blob
+        val blob = "blob".toByteArray(Charsets.UTF_8)
+        assert(decoder.decode("C9P6YRG".toByteArray(Charsets.UTF_8)).toString(Charsets.UTF_8) == "blob")
+    }
+}
+