crypto: ixp4xx - Simplify and harden key parsing

Use the common helper function crypto_authenc_extractkeys() for key
parsing. Also ensure the keys do fit into the corresponding buffers.
Otherwise memory corruption might occur.

Cc: Christian Hohnstaedt <chohnstaedt@innominate.com>
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/drivers/crypto/ixp4xx_crypto.c b/drivers/crypto/ixp4xx_crypto.c
index 21180d6cad6e27f2f316a04b1e98fb2e61ac90d3..153f73c12d3e7895dfdaa078543d801238536fa8 100644 (file)
--- a/drivers/crypto/ixp4xx_crypto.c
+++ b/drivers/crypto/ixp4xx_crypto.c
@@ -1159,32 +1159,24 @@ static int aead_setkey(struct crypto_aead *tfm, const u8 *key,
                        unsigned int keylen)
 {
        struct ixp_ctx *ctx = crypto_aead_ctx(tfm);
-       struct rtattr *rta = (struct rtattr *)key;
-       struct crypto_authenc_key_param *param;
+       struct crypto_authenc_keys keys;
 
-       if (!RTA_OK(rta, keylen))
-               goto badkey;
-       if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
-               goto badkey;
-       if (RTA_PAYLOAD(rta) < sizeof(*param))
+       if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
                goto badkey;
 
-       param = RTA_DATA(rta);
-       ctx->enckey_len = be32_to_cpu(param->enckeylen);
-
-       key += RTA_ALIGN(rta->rta_len);
-       keylen -= RTA_ALIGN(rta->rta_len);
+       if (keys.authkeylen > sizeof(ctx->authkey))
+               goto badkey;
 
-       if (keylen < ctx->enckey_len)
+       if (keys.enckeylen > sizeof(ctx->enckey))
                goto badkey;
 
-       ctx->authkey_len = keylen - ctx->enckey_len;
-       memcpy(ctx->enckey, key + ctx->authkey_len, ctx->enckey_len);
-       memcpy(ctx->authkey, key, ctx->authkey_len);
+       memcpy(ctx->authkey, keys.authkey, keys.authkeylen);
+       memcpy(ctx->enckey, keys.enckey, keys.enckeylen);
+       ctx->authkey_len = keys.authkeylen;
+       ctx->enckey_len = keys.enckeylen;
 
        return aead_setup(tfm, crypto_aead_authsize(tfm));
 badkey:
-       ctx->enckey_len = 0;
        crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
        return -EINVAL;
 }