GitLab

(POLARSSL_RIPEMD160_ALT)

If one of the calls to mpi_grow() before setting Apos would fail, then
mpi_free( &Apos ) would be executed without Apos being initialised.

Makes secp256k1 about 4x faster

Only affects curves with nbits != pbits (currently only secp224k1)

The issue would happen for curves whose bitlength is not a multiple of eight
(the only case is NIST P-521) with hashes that are longer than the bitlength
of the curve: since the wides hash is 512 bits long, this can't happen.
Fixing however as a matter of principle and readability.