Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v3 1/2] staging: rtl8188eu: Replace a custom function with crc32_le() | Date | Thu, 22 Jul 2021 15:30:08 +0000 |
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From: Fabio M. De Francesco > Sent: 21 July 2021 12:01 > > Use crc32_le() in place of the custom getcrc32(). > ... > @@ -609,14 +595,15 @@ u32 rtw_tkip_encrypt(struct adapter *padapter, struct xmit_frame > *pxmitframe) > > if ((curfragnum + 1) == pattrib->nr_frags) { /* 4 the last fragment */ > length = pattrib->last_txcmdsz - pattrib->hdrlen - pattrib->iv_len - > pattrib->icv_len; > - *((__le32 *)crc) = getcrc32(payload, length);/* modified by Amy*/ > + *((__le32 *)crc) = cpu_to_le32(~crc32_le(~0, payload, length)); > > arcfour_init(&mycontext, rc4key, 16); > arcfour_encrypt(&mycontext, payload, payload, length); > arcfour_encrypt(&mycontext, payload + length, crc, 4); > } else { > length = pxmitpriv->frag_len - pattrib->hdrlen - pattrib->iv_len - > pattrib->icv_len; > - *((__le32 *)crc) = getcrc32(payload, length);/* modified by Amy*/ > + *((__le32 *)crc) = cpu_to_le32(~crc32_le(~0, payload, length)); > + > arcfour_init(&mycontext, rc4key, 16); > arcfour_encrypt(&mycontext, payload, payload, length); > arcfour_encrypt(&mycontext, payload + length, crc, 4);
Change crc to be __le32, kill the casts and pass &crc in the last call.
> @@ -682,7 +669,7 @@ u32 rtw_tkip_decrypt(struct adapter *padapter, struct recv_frame *precvframe) > arcfour_init(&mycontext, rc4key, 16); > arcfour_encrypt(&mycontext, payload, payload, length); > > - *((__le32 *)crc) = getcrc32(payload, length - 4); > + *((__le32 *)crc) = cpu_to_le32(~crc32_le(~0, payload, length - 4)); > > if (crc[3] != payload[length - 1] || > crc[2] != payload[length - 2] ||
You could to the same here, or make crc u32, remove the cpu_to_le32() and use get_unaligned_u32(payload + length - 4) (or whatever it is called).
But it is much better to do: crc = crc32_le(~0, payload, length); if (crc != VALID_CRC32) res = _FAIL;
You can lookup VALID_CRC32, but it is crc32_le(0, "\xff\xff\xff\xff", 4);
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
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