BF_cbc_encrypt
void BF_cbc_encrypt(const unsigned char *, unsigned char *, long,
BF_cbc_encrypt(blkno, iv, CGD_BF_BLOCK_SIZE, &bp->bp_key, zero,
BF_cbc_encrypt(src, dst, nbytes, &bp->bp_key, iv,
BF_cbc_encrypt(src, dst, nbytes, &bp->bp_key, iv,