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: Mathias Krause <mathias.krause@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/authenc.c b/crypto/authenc.c
index 2b3f4abda9291c217158647e44daad03871b7567..1875e7026e8f7fad661e2051cdc139f733d6c19a 100644 (file)
--- a/crypto/authenc.c
+++ b/crypto/authenc.c
@@ -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,
-                                unsigned int keylen)
+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);
 

diff --git a/include/crypto/authenc.h b/include/crypto/authenc.h
index e47b044929a84b7cd1e54fb17b8e87de3020d7b6..6775059539b56f2ffe870d28c4d2ab35821c013a 100644 (file)
--- a/include/crypto/authenc.h
+++ b/include/crypto/authenc.h
@@ -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 */