Merge "Stop using charAt for Signatures"

     * {@link #toChars} or {@link #toCharsString()}.

     */

    public Signature(String text) {

        final int N = text.length()/2;

        byte[] sig = new byte[N];

        for (int i=0; i<N; i++) {

            char c = text.charAt(i*2);

            byte b = (byte)(

                    (c >= 'a' ? (c - 'a' + 10) : (c - '0'))<<4);

            c = text.charAt(i*2 + 1);

            b |= (byte)(c >= 'a' ? (c - 'a' + 10) : (c - '0'));

            sig[i] = b;

        final byte[] input = text.getBytes();

        final int N = input.length;

        final byte[] sig = new byte[N / 2];

        int sigIndex = 0;

        for (int i = 0; i < N;) {

            int b;

            final int hi = input[i++];

            b = (hi >= 'a' ? (hi - 'a' + 10) : (hi - '0')) << 4;

            final int lo = input[i++];

            b |= (lo >= 'a' ? (lo - 'a' + 10) : (lo - '0')) & 0x0F;

            sig[sigIndex++] = (byte) (b & 0xFF);

        }

        mSignature = sig;

    }