Commit bc6e2bdb authored by Mathias Krause's avatar Mathias Krause Committed by Herbert Xu
Browse files

crypto: authenc - Export key parsing helper function 



AEAD key parsing is duplicated to multiple places in the kernel. Add a
common helper function to consolidate that functionality.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: default avatarMathias Krause <mathias.krause@secunet.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 6d3aab4e

crypto/authenc.c

+30 −18
Original line number Diff line number Diff line
@@ -52,40 +52,52 @@ static void authenc_request_complete(struct aead_request *req, int err) 
		aead_request_complete(req, err);

}



static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,

int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,

			       unsigned int keylen)

{

	unsigned int authkeylen;

	unsigned int enckeylen;

	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);

	struct crypto_ahash *auth = ctx->auth;

	struct crypto_ablkcipher *enc = ctx->enc;

	struct rtattr *rta = (void *)key;

	struct rtattr *rta = (struct rtattr *)key;

	struct crypto_authenc_key_param *param;

	int err = -EINVAL;



	if (!RTA_OK(rta, keylen))

		goto badkey;

		return -EINVAL;

	if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)

		goto badkey;

		return -EINVAL;

	if (RTA_PAYLOAD(rta) < sizeof(*param))

		goto badkey;

		return -EINVAL;



	param = RTA_DATA(rta);

	enckeylen = be32_to_cpu(param->enckeylen);

	keys->enckeylen = be32_to_cpu(param->enckeylen);



	key += RTA_ALIGN(rta->rta_len);

	keylen -= RTA_ALIGN(rta->rta_len);



	if (keylen < enckeylen)

		goto badkey;

	if (keylen < keys->enckeylen)

		return -EINVAL;



	authkeylen = keylen - enckeylen;

	keys->authkeylen = keylen - keys->enckeylen;

	keys->authkey = key;

	keys->enckey = key + keys->authkeylen;



	return 0;

}

EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys);



static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,

				 unsigned int keylen)

{

	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);

	struct crypto_ahash *auth = ctx->auth;

	struct crypto_ablkcipher *enc = ctx->enc;

	struct crypto_authenc_keys keys;

	int err = -EINVAL;



	if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)

		goto badkey;



	crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);

	crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) &

				    CRYPTO_TFM_REQ_MASK);

	err = crypto_ahash_setkey(auth, key, authkeylen);

	err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen);

	crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) &

				       CRYPTO_TFM_RES_MASK);
@@ -95,7 +107,7 @@ static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key, 
	crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);

	crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &

					 CRYPTO_TFM_REQ_MASK);

	err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);

	err = crypto_ablkcipher_setkey(enc, keys.enckey, keys.enckeylen);

	crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &

				       CRYPTO_TFM_RES_MASK);

include/crypto/authenc.h

+11 −1
Original line number Diff line number Diff line
@@ -23,5 +23,15 @@ struct crypto_authenc_key_param { 
	__be32 enckeylen;

};



#endif	/* _CRYPTO_AUTHENC_H */

struct crypto_authenc_keys {

	const u8 *authkey;

	const u8 *enckey;



	unsigned int authkeylen;

	unsigned int enckeylen;

};



int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,

			       unsigned int keylen);



#endif	/* _CRYPTO_AUTHENC_H */

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