md5_blocks
md5_blocks(&ctx->state, ctx->buf, 1);
md5_blocks(&ctx->state, data, nblocks);
md5_blocks(&ctx->state, ctx->buf, 1);
md5_blocks(&ctx->state, ctx->buf, 1);
md5_blocks(istate, derived_key.b, 1);
md5_blocks(ostate, derived_key.b, 1);
md5_blocks(&ctx->ostate, ctx->hash_ctx.buf, 1);