Cannot output correct hash in Java. What is wrong?

Question

In my Android app I have a SHA256 hash which I must further hash with the RIPEMD160 message digest algorithm.

I can output the correct sha256 and ripemd160 hash of any s

Answer 1

Your "online calculator" result is the result of hashing the bytes of the string "test" with SHA-256, converting the result of that hash to a hex string, then taking the bytes corresponding to the ASCII characters of that hex string and hashing those a second time. This is very different from your Java code, which passes the bytes that come out of the first hash directly to the second one, without printing them as hex and turning those characters back into bytes in between. The single byte with value 254 (decimal) becomes "fe" in hex, which becomes the two-byte sequence [0x66, 0x65] when converted back to bytes.