int cca_cipher2protkey()

in crypto/zcrypt_ccamisc.c [1183:1346]
139 lines of code
17 McCabe index (conditional complexity)

int cca_cipher2protkey(u16 cardnr, u16 domain, const u8 *ckey,
		       u8 *protkey, u32 *protkeylen, u32 *protkeytype)
{
	int rc;
	u8 *mem, *ptr;
	struct CPRBX *preqcblk, *prepcblk;
	struct ica_xcRB xcrb;
	struct aureqparm {
		u8  subfunc_code[2];
		u16 rule_array_len;
		u8  rule_array[8];
		struct {
			u16 len;
			u16 tk_blob_len;
			u16 tk_blob_tag;
			u8  tk_blob[66];
		} vud;
		struct {
			u16 len;
			u16 cca_key_token_len;
			u16 cca_key_token_flags;
			u8  cca_key_token[0]; // 64 or more
		} kb;
	} __packed * preqparm;
	struct aurepparm {
		u8  subfunc_code[2];
		u16 rule_array_len;
		struct {
			u16 len;
			u16 sublen;
			u16 tag;
			struct cpacfkeyblock {
				u8  version;  /* version of this struct */
				u8  flags[2];
				u8  algo;
				u8  form;
				u8  pad1[3];
				u16 keylen;
				u8  key[64];  /* the key (keylen bytes) */
				u16 keyattrlen;
				u8  keyattr[32];
				u8  pad2[1];
				u8  vptype;
				u8  vp[32];  /* verification pattern */
			} ckb;
		} vud;
		struct {
			u16 len;
		} kb;
	} __packed * prepparm;
	int keytoklen = ((struct cipherkeytoken *)ckey)->len;

	/* 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 AU request */
	preqparm = (struct aureqparm __force *) preqcblk->req_parmb;
	memcpy(preqparm->subfunc_code, "AU", 2);
	preqparm->rule_array_len =
		sizeof(preqparm->rule_array_len)
		+ sizeof(preqparm->rule_array);
	memcpy(preqparm->rule_array, "EXPT-SK ", 8);
	/* vud, tk blob */
	preqparm->vud.len = sizeof(preqparm->vud);
	preqparm->vud.tk_blob_len = sizeof(preqparm->vud.tk_blob)
		+ 2 * sizeof(uint16_t);
	preqparm->vud.tk_blob_tag = 0x00C2;
	/* kb, cca token */
	preqparm->kb.len = keytoklen + 3 * sizeof(uint16_t);
	preqparm->kb.cca_key_token_len = keytoklen + 2 * sizeof(uint16_t);
	memcpy(preqparm->kb.cca_key_token, ckey, keytoklen);
	/* now fill length of param block into cprb */
	preqcblk->req_parml = sizeof(struct aureqparm) + keytoklen;

	/* 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 unwrap secure key failure, card response %d/%d\n",
			__func__,
			(int) prepcblk->ccp_rtcode,
			(int) prepcblk->ccp_rscode);
		if (prepcblk->ccp_rtcode == 8 && prepcblk->ccp_rscode == 2290)
			rc = -EAGAIN;
		else
			rc = -EIO;
		goto out;
	}
	if (prepcblk->ccp_rscode != 0) {
		DEBUG_WARN(
			"%s unwrap secure key warning, card response %d/%d\n",
			__func__,
			(int) prepcblk->ccp_rtcode,
			(int) prepcblk->ccp_rscode);
	}

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

	/* check the returned keyblock */
	if (prepparm->vud.ckb.version != 0x01 &&
	    prepparm->vud.ckb.version != 0x02) {
		DEBUG_ERR("%s reply param keyblock version mismatch 0x%02x\n",
			  __func__, (int) prepparm->vud.ckb.version);
		rc = -EIO;
		goto out;
	}
	if (prepparm->vud.ckb.algo != 0x02) {
		DEBUG_ERR(
			"%s reply param keyblock algo mismatch 0x%02x != 0x02\n",
			__func__, (int) prepparm->vud.ckb.algo);
		rc = -EIO;
		goto out;
	}

	/* copy the translated protected key */
	switch (prepparm->vud.ckb.keylen) {
	case 16+32:
		/* AES 128 protected key */
		if (protkeytype)
			*protkeytype = PKEY_KEYTYPE_AES_128;
		break;
	case 24+32:
		/* AES 192 protected key */
		if (protkeytype)
			*protkeytype = PKEY_KEYTYPE_AES_192;
		break;
	case 32+32:
		/* AES 256 protected key */
		if (protkeytype)
			*protkeytype = PKEY_KEYTYPE_AES_256;
		break;
	default:
		DEBUG_ERR("%s unknown/unsupported keylen %d\n",
			  __func__, prepparm->vud.ckb.keylen);
		rc = -EIO;
		goto out;
	}
	memcpy(protkey, prepparm->vud.ckb.key, prepparm->vud.ckb.keylen);
	if (protkeylen)
		*protkeylen = prepparm->vud.ckb.keylen;

out:
	free_cprbmem(mem, PARMBSIZE, 0);
	return rc;
}