int cca_clr2seckey()

in crypto/zcrypt_ccamisc.c [440:573]
112 lines of code
13 McCabe index (conditional complexity)

int cca_clr2seckey(u16 cardnr, u16 domain, u32 keybitsize,
		   const u8 *clrkey, u8 *seckey)
{
	int rc, keysize, seckeysize;
	u8 *mem, *ptr;
	struct CPRBX *preqcblk, *prepcblk;
	struct ica_xcRB xcrb;
	struct cmreqparm {
		u8  subfunc_code[2];
		u16 rule_array_len;
		char  rule_array[8];
		struct lv1 {
			u16 len;
			u8  clrkey[0];
		} lv1;
		struct lv2 {
			u16 len;
			struct keyid {
				u16 len;
				u16 attr;
				u8  data[SECKEYBLOBSIZE];
			} keyid;
		} lv2;
	} __packed * preqparm;
	struct lv2 *plv2;
	struct cmrepparm {
		u8  subfunc_code[2];
		u16 rule_array_len;
		struct lv3 {
			u16 len;
			u16 keyblocklen;
			struct {
				u16 toklen;
				u16 tokattr;
				u8  tok[];
				/* ... some more data ... */
			} keyblock;
		} lv3;
	} __packed * prepparm;

	/* get already prepared memory for 2 cprbs with param block each */
	rc = alloc_and_prep_cprbmem(PARMBSIZE, &mem, &preqcblk, &prepcblk);
	if (rc)
		return rc;

	/* fill request cprb struct */
	preqcblk->domain = domain;

	/* fill request cprb param block with CM request */
	preqparm = (struct cmreqparm __force *) preqcblk->req_parmb;
	memcpy(preqparm->subfunc_code, "CM", 2);
	memcpy(preqparm->rule_array, "AES     ", 8);
	preqparm->rule_array_len =
		sizeof(preqparm->rule_array_len) + sizeof(preqparm->rule_array);
	switch (keybitsize) {
	case PKEY_SIZE_AES_128:
	case PKEY_KEYTYPE_AES_128: /* older ioctls used this */
		keysize = 16;
		break;
	case PKEY_SIZE_AES_192:
	case PKEY_KEYTYPE_AES_192: /* older ioctls used this */
		keysize = 24;
		break;
	case PKEY_SIZE_AES_256:
	case PKEY_KEYTYPE_AES_256: /* older ioctls used this */
		keysize = 32;
		break;
	default:
		DEBUG_ERR("%s unknown/unsupported keybitsize %d\n",
			  __func__, keybitsize);
		rc = -EINVAL;
		goto out;
	}
	preqparm->lv1.len = sizeof(struct lv1) + keysize;
	memcpy(preqparm->lv1.clrkey, clrkey, keysize);
	plv2 = (struct lv2 *) (((u8 *) &preqparm->lv2) + keysize);
	plv2->len = sizeof(struct lv2);
	plv2->keyid.len = sizeof(struct keyid);
	plv2->keyid.attr = 0x30;
	preqcblk->req_parml = sizeof(struct cmreqparm) + keysize;

	/* fill xcrb struct */
	prep_xcrb(&xcrb, cardnr, preqcblk, prepcblk);

	/* forward xcrb with request CPRB and reply CPRB to zcrypt dd */
	rc = zcrypt_send_cprb(&xcrb);
	if (rc) {
		DEBUG_ERR("%s zcrypt_send_cprb (cardnr=%d domain=%d) failed, rc=%d\n",
			  __func__, (int) cardnr, (int) domain, rc);
		goto out;
	}

	/* check response returncode and reasoncode */
	if (prepcblk->ccp_rtcode != 0) {
		DEBUG_ERR("%s clear key import failure, card response %d/%d\n",
			  __func__,
			  (int) prepcblk->ccp_rtcode,
			  (int) prepcblk->ccp_rscode);
		rc = -EIO;
		goto out;
	}

	/* process response cprb param block */
	ptr = ((u8 *) prepcblk) + sizeof(struct CPRBX);
	prepcblk->rpl_parmb = (u8 __user *) ptr;
	prepparm = (struct cmrepparm *) ptr;

	/* check length of the returned secure key token */
	seckeysize = prepparm->lv3.keyblock.toklen
		- sizeof(prepparm->lv3.keyblock.toklen)
		- sizeof(prepparm->lv3.keyblock.tokattr);
	if (seckeysize != SECKEYBLOBSIZE) {
		DEBUG_ERR("%s secure token size mismatch %d != %d bytes\n",
			  __func__, seckeysize, SECKEYBLOBSIZE);
		rc = -EIO;
		goto out;
	}

	/* check secure key token */
	rc = cca_check_secaeskeytoken(zcrypt_dbf_info, DBF_ERR,
				      prepparm->lv3.keyblock.tok, 8*keysize);
	if (rc) {
		rc = -EIO;
		goto out;
	}

	/* copy the generated secure key token */
	if (seckey)
		memcpy(seckey, prepparm->lv3.keyblock.tok, SECKEYBLOBSIZE);

out:
	free_cprbmem(mem, PARMBSIZE, 1);
	return rc;
}