I used 3 resources
I can’t get the first test vector to work out.
I SHA256 0x00000000000000000000000000000000 into 374708fff7719dd5979ec875d56cd2286f6d3cf7ec317a3b25632aab28ec37bb
The first four checksum bits are 0b1101
The makes the last 11 bits (the last word) 0b00000001101
which is word 13 or index 12 “accident”. However in the test vector it’s index 4 “about”.
I get the wrong word for every test vector. Probably a silly mistake. Thanks.