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staging: rtl8192e: rtllib_crypt_ccmp.c: Use crypto API ccm(aes)
Use ccm(aes) aead transform instead of invoking the AES block cipher block by block. Signed-off-by: Christina Quast <contact@christina-quast.de> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Link: https://lore.kernel.org/r/20190816065936.12214-3-contact@christina-quast.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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parent
eb0e7bf3ca
commit
5ee5265674
2 changed files with 78 additions and 110 deletions
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@ -15,6 +15,7 @@ config RTLLIB_CRYPTO_CCMP
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tristate "Support for rtllib CCMP crypto"
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depends on RTLLIB
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select CRYPTO_AES
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select CRYPTO_CCM
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default y
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help
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CCMP crypto driver for rtllib.
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@ -17,6 +17,7 @@
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#include "rtllib.h"
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#include <linux/crypto.h>
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#include <crypto/aead.h>
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#include <linux/scatterlist.h>
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@ -39,20 +40,13 @@ struct rtllib_ccmp_data {
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int key_idx;
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struct crypto_tfm *tfm;
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struct crypto_aead *tfm;
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/* scratch buffers for virt_to_page() (crypto API) */
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u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
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tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
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u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
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u8 tx_aad[2 * AES_BLOCK_LEN];
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u8 rx_aad[2 * AES_BLOCK_LEN];
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};
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static void rtllib_ccmp_aes_encrypt(struct crypto_tfm *tfm,
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const u8 pt[16], u8 ct[16])
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{
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crypto_cipher_encrypt_one((void *)tfm, ct, pt);
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}
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static void *rtllib_ccmp_init(int key_idx)
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{
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struct rtllib_ccmp_data *priv;
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@ -62,7 +56,7 @@ static void *rtllib_ccmp_init(int key_idx)
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goto fail;
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priv->key_idx = key_idx;
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priv->tfm = (void *)crypto_alloc_cipher("aes", 0, 0);
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priv->tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
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if (IS_ERR(priv->tfm)) {
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pr_debug("Could not allocate crypto API aes\n");
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priv->tfm = NULL;
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@ -73,7 +67,7 @@ static void *rtllib_ccmp_init(int key_idx)
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fail:
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if (priv) {
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if (priv->tfm)
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crypto_free_cipher((void *)priv->tfm);
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crypto_free_aead(priv->tfm);
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kfree(priv);
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}
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@ -86,31 +80,18 @@ static void rtllib_ccmp_deinit(void *priv)
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struct rtllib_ccmp_data *_priv = priv;
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if (_priv && _priv->tfm)
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crypto_free_cipher((void *)_priv->tfm);
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crypto_free_aead(_priv->tfm);
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kfree(priv);
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}
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static inline void xor_block(u8 *b, u8 *a, size_t len)
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{
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int i;
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for (i = 0; i < len; i++)
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b[i] ^= a[i];
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}
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static void ccmp_init_blocks(struct crypto_tfm *tfm,
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struct rtllib_hdr_4addr *hdr,
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u8 *pn, size_t dlen, u8 *b0, u8 *auth,
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u8 *s0)
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static int ccmp_init_iv_and_aad(struct rtllib_hdr_4addr *hdr,
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u8 *pn, u8 *iv, u8 *aad)
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{
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u8 *pos, qc = 0;
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size_t aad_len;
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u16 fc;
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int a4_included, qc_included;
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u8 aad[2 * AES_BLOCK_LEN];
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fc = le16_to_cpu(hdr->frame_ctl);
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a4_included = ((fc & (RTLLIB_FCTL_TODS | RTLLIB_FCTL_FROMDS)) ==
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@ -128,18 +109,19 @@ static void ccmp_init_blocks(struct crypto_tfm *tfm,
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qc = *pos & 0x0f;
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aad_len += 2;
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}
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/* CCM Initial Block:
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* Flag (Include authentication header, M=3 (8-octet MIC),
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* L=1 (2-octet Dlen))
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* Nonce: 0x00 | A2 | PN
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* Dlen
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/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
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* mode authentication are not allowed to collide, yet both are derived
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* from the same vector. We only set L := 1 here to indicate that the
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* data size can be represented in (L+1) bytes. The CCM layer will take
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* care of storing the data length in the top (L+1) bytes and setting
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* and clearing the other bits as is required to derive the two IVs.
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*/
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b0[0] = 0x59;
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b0[1] = qc;
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memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
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memcpy(b0 + 8, pn, CCMP_PN_LEN);
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b0[14] = (dlen >> 8) & 0xff;
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b0[15] = dlen & 0xff;
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iv[0] = 0x1;
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/* Nonce: QC | A2 | PN */
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iv[1] = qc;
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memcpy(iv + 2, hdr->addr2, ETH_ALEN);
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memcpy(iv + 8, pn, CCMP_PN_LEN);
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/* AAD:
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* FC with bits 4..6 and 11..13 masked to zero; 14 is always one
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@ -149,31 +131,21 @@ static void ccmp_init_blocks(struct crypto_tfm *tfm,
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* QC (if present)
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*/
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pos = (u8 *) hdr;
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aad[0] = 0; /* aad_len >> 8 */
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aad[1] = aad_len & 0xff;
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aad[2] = pos[0] & 0x8f;
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aad[3] = pos[1] & 0xc7;
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memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
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aad[0] = pos[0] & 0x8f;
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aad[1] = pos[1] & 0xc7;
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memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN);
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pos = (u8 *) &hdr->seq_ctl;
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aad[22] = pos[0] & 0x0f;
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aad[23] = 0; /* all bits masked */
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memset(aad + 24, 0, 8);
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aad[20] = pos[0] & 0x0f;
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aad[21] = 0; /* all bits masked */
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memset(aad + 22, 0, 8);
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if (a4_included)
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memcpy(aad + 24, hdr->addr4, ETH_ALEN);
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memcpy(aad + 22, hdr->addr4, ETH_ALEN);
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if (qc_included) {
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aad[a4_included ? 30 : 24] = qc;
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aad[a4_included ? 28 : 22] = qc;
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/* rest of QC masked */
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}
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/* Start with the first block and AAD */
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rtllib_ccmp_aes_encrypt(tfm, b0, auth);
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xor_block(auth, aad, AES_BLOCK_LEN);
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rtllib_ccmp_aes_encrypt(tfm, auth, auth);
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xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
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rtllib_ccmp_aes_encrypt(tfm, auth, auth);
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b0[0] &= 0x07;
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b0[14] = b0[15] = 0;
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rtllib_ccmp_aes_encrypt(tfm, b0, s0);
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return aad_len;
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}
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@ -213,40 +185,37 @@ static int rtllib_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
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*pos++ = key->tx_pn[1];
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*pos++ = key->tx_pn[0];
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hdr = (struct rtllib_hdr_4addr *) skb->data;
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if (!tcb_desc->bHwSec) {
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int blocks, last, len;
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u8 *mic;
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u8 *b0 = key->tx_b0;
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u8 *b = key->tx_b;
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u8 *e = key->tx_e;
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u8 *s0 = key->tx_s0;
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struct aead_request *req;
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struct scatterlist sg[2];
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u8 *aad = key->tx_aad;
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u8 iv[AES_BLOCK_LEN];
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int aad_len, ret;
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int data_len = skb->len - hdr_len - CCMP_HDR_LEN;
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mic = skb_put(skb, CCMP_MIC_LEN);
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req = aead_request_alloc(key->tfm, GFP_ATOMIC);
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if (!req)
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return -ENOMEM;
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ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len,
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b0, b, s0);
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aad_len = ccmp_init_iv_and_aad(hdr, key->tx_pn, iv, aad);
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blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
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last = data_len % AES_BLOCK_LEN;
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skb_put(skb, CCMP_MIC_LEN);
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sg_init_table(sg, 2);
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sg_set_buf(&sg[0], aad, aad_len);
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sg_set_buf(&sg[1], skb->data + hdr_len + CCMP_HDR_LEN,
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data_len + CCMP_MIC_LEN);
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for (i = 1; i <= blocks; i++) {
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len = (i == blocks && last) ? last : AES_BLOCK_LEN;
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/* Authentication */
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xor_block(b, pos, len);
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rtllib_ccmp_aes_encrypt(key->tfm, b, b);
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/* Encryption, with counter */
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b0[14] = (i >> 8) & 0xff;
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b0[15] = i & 0xff;
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rtllib_ccmp_aes_encrypt(key->tfm, b0, e);
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xor_block(pos, e, len);
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pos += len;
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}
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aead_request_set_callback(req, 0, NULL, NULL);
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aead_request_set_ad(req, aad_len);
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aead_request_set_crypt(req, sg, sg, data_len, iv);
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for (i = 0; i < CCMP_MIC_LEN; i++)
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mic[i] = b[i] ^ s0[i];
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ret = crypto_aead_encrypt(req);
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aead_request_free(req);
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return ret;
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}
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return 0;
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}
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@ -302,35 +271,31 @@ static int rtllib_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
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return -4;
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}
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if (!tcb_desc->bHwSec) {
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size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN -
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CCMP_MIC_LEN;
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u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
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u8 *b0 = key->rx_b0;
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u8 *b = key->rx_b;
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u8 *a = key->rx_a;
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int i, blocks, last, len;
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size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN;
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struct aead_request *req;
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struct scatterlist sg[2];
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u8 *aad = key->rx_aad;
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u8 iv[AES_BLOCK_LEN];
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int aad_len, ret;
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req = aead_request_alloc(key->tfm, GFP_ATOMIC);
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if(!req)
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return -ENOMEM;
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ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
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xor_block(mic, b, CCMP_MIC_LEN);
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aad_len = ccmp_init_iv_and_aad(hdr, pn, iv, aad);
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blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
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last = data_len % AES_BLOCK_LEN;
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sg_init_table(sg, 2);
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sg_set_buf(&sg[0], aad, aad_len);
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sg_set_buf(&sg[1], pos, data_len);
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for (i = 1; i <= blocks; i++) {
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len = (i == blocks && last) ? last : AES_BLOCK_LEN;
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/* Decrypt, with counter */
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b0[14] = (i >> 8) & 0xff;
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b0[15] = i & 0xff;
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rtllib_ccmp_aes_encrypt(key->tfm, b0, b);
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xor_block(pos, b, len);
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/* Authentication */
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xor_block(a, pos, len);
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rtllib_ccmp_aes_encrypt(key->tfm, a, a);
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pos += len;
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}
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aead_request_set_callback(req, 0, NULL, NULL);
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aead_request_set_ad(req, aad_len);
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aead_request_set_crypt(req, sg, sg, data_len, iv);
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if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
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ret = crypto_aead_decrypt(req);
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aead_request_free(req);
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if (ret) {
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if (net_ratelimit()) {
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pr_debug("CCMP: decrypt failed: STA= %pM\n",
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hdr->addr2);
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{
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struct rtllib_ccmp_data *data = priv;
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int keyidx;
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struct crypto_tfm *tfm = data->tfm;
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struct crypto_aead *tfm = data->tfm;
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keyidx = data->key_idx;
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memset(data, 0, sizeof(*data));
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data->rx_pn[4] = seq[1];
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data->rx_pn[5] = seq[0];
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}
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crypto_cipher_setkey((void *)data->tfm, data->key, CCMP_TK_LEN);
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if (crypto_aead_setauthsize(data->tfm, CCMP_MIC_LEN) ||
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crypto_aead_setkey(data->tfm, data->key, CCMP_TK_LEN))
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return -1;
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} else if (len == 0) {
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data->key_set = 0;
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} else {
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