diff options
| -rw-r--r-- | net/mac80211/Kconfig | 1 | ||||
| -rw-r--r-- | net/mac80211/aes_ccm.c | 169 | ||||
| -rw-r--r-- | net/mac80211/aes_ccm.h | 14 | ||||
| -rw-r--r-- | net/mac80211/key.h | 2 | ||||
| -rw-r--r-- | net/mac80211/wpa.c | 44 |
5 files changed, 84 insertions, 146 deletions
diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig index 62535fe9f570..dc31ec3db404 100644 --- a/net/mac80211/Kconfig +++ b/net/mac80211/Kconfig @@ -4,6 +4,7 @@ config MAC80211 select CRYPTO select CRYPTO_ARC4 select CRYPTO_AES + select CRYPTO_CCM select CRC32 select AVERAGE ---help--- diff --git a/net/mac80211/aes_ccm.c b/net/mac80211/aes_ccm.c index be7614b9ed27..7c7df475a401 100644 --- a/net/mac80211/aes_ccm.c +++ b/net/mac80211/aes_ccm.c @@ -2,6 +2,8 @@ * Copyright 2003-2004, Instant802 Networks, Inc. * Copyright 2005-2006, Devicescape Software, Inc. * + * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org> + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. @@ -17,134 +19,75 @@ #include "key.h" #include "aes_ccm.h" -static void aes_ccm_prepare(struct crypto_cipher *tfm, u8 *scratch, u8 *a) +void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, + u8 *data, size_t data_len, u8 *mic) { - int i; - u8 *b_0, *aad, *b, *s_0; - - b_0 = scratch + 3 * AES_BLOCK_SIZE; - aad = scratch + 4 * AES_BLOCK_SIZE; - b = scratch; - s_0 = scratch + AES_BLOCK_SIZE; - - crypto_cipher_encrypt_one(tfm, b, b_0); + struct scatterlist assoc, pt, ct[2]; + struct { + struct aead_request req; + u8 priv[crypto_aead_reqsize(tfm)]; + } aead_req; - /* Extra Authenticate-only data (always two AES blocks) */ - for (i = 0; i < AES_BLOCK_SIZE; i++) - aad[i] ^= b[i]; - crypto_cipher_encrypt_one(tfm, b, aad); + memset(&aead_req, 0, sizeof(aead_req)); - aad += AES_BLOCK_SIZE; + sg_init_one(&pt, data, data_len); + sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad)); + sg_init_table(ct, 2); + sg_set_buf(&ct[0], data, data_len); + sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN); - for (i = 0; i < AES_BLOCK_SIZE; i++) - aad[i] ^= b[i]; - crypto_cipher_encrypt_one(tfm, a, aad); + aead_request_set_tfm(&aead_req.req, tfm); + aead_request_set_assoc(&aead_req.req, &assoc, assoc.length); + aead_request_set_crypt(&aead_req.req, &pt, ct, data_len, b_0); - /* Mask out bits from auth-only-b_0 */ - b_0[0] &= 0x07; - - /* S_0 is used to encrypt T (= MIC) */ - b_0[14] = 0; - b_0[15] = 0; - crypto_cipher_encrypt_one(tfm, s_0, b_0); + crypto_aead_encrypt(&aead_req.req); } - -void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch, - u8 *data, size_t data_len, - u8 *cdata, u8 *mic) +int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, + u8 *data, size_t data_len, u8 *mic) { - int i, j, last_len, num_blocks; - u8 *pos, *cpos, *b, *s_0, *e, *b_0; - - b = scratch; - s_0 = scratch + AES_BLOCK_SIZE; - e = scratch + 2 * AES_BLOCK_SIZE; - b_0 = scratch + 3 * AES_BLOCK_SIZE; - - num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_SIZE); - last_len = data_len % AES_BLOCK_SIZE; - aes_ccm_prepare(tfm, scratch, b); - - /* Process payload blocks */ - pos = data; - cpos = cdata; - for (j = 1; j <= num_blocks; j++) { - int blen = (j == num_blocks && last_len) ? - last_len : AES_BLOCK_SIZE; - - /* Authentication followed by encryption */ - for (i = 0; i < blen; i++) - b[i] ^= pos[i]; - crypto_cipher_encrypt_one(tfm, b, b); - - b_0[14] = (j >> 8) & 0xff; - b_0[15] = j & 0xff; - crypto_cipher_encrypt_one(tfm, e, b_0); - for (i = 0; i < blen; i++) - *cpos++ = *pos++ ^ e[i]; - } - - for (i = 0; i < IEEE80211_CCMP_MIC_LEN; i++) - mic[i] = b[i] ^ s_0[i]; + struct scatterlist assoc, pt, ct[2]; + struct { + struct aead_request req; + u8 priv[crypto_aead_reqsize(tfm)]; + } aead_req; + + memset(&aead_req, 0, sizeof(aead_req)); + + sg_init_one(&pt, data, data_len); + sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad)); + sg_init_table(ct, 2); + sg_set_buf(&ct[0], data, data_len); + sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN); + + aead_request_set_tfm(&aead_req.req, tfm); + aead_request_set_assoc(&aead_req.req, &assoc, assoc.length); + aead_request_set_crypt(&aead_req.req, ct, &pt, + data_len + IEEE80211_CCMP_MIC_LEN, b_0); + + return crypto_aead_decrypt(&aead_req.req); } - -int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch, - u8 *cdata, size_t data_len, u8 *mic, u8 *data) +struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[]) { - int i, j, last_len, num_blocks; - u8 *pos, *cpos, *b, *s_0, *a, *b_0; - - b = scratch; - s_0 = scratch + AES_BLOCK_SIZE; - a = scratch + 2 * AES_BLOCK_SIZE; - b_0 = scratch + 3 * AES_BLOCK_SIZE; - - num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_SIZE); - last_len = data_len % AES_BLOCK_SIZE; - aes_ccm_prepare(tfm, scratch, a); - - /* Process payload blocks */ - cpos = cdata; - pos = data; - for (j = 1; j <= num_blocks; j++) { - int blen = (j == num_blocks && last_len) ? - last_len : AES_BLOCK_SIZE; - - /* Decryption followed by authentication */ - b_0[14] = (j >> 8) & 0xff; - b_0[15] = j & 0xff; - crypto_cipher_encrypt_one(tfm, b, b_0); - for (i = 0; i < blen; i++) { - *pos = *cpos++ ^ b[i]; - a[i] ^= *pos++; - } - crypto_cipher_encrypt_one(tfm, a, a); - } - - for (i = 0; i < IEEE80211_CCMP_MIC_LEN; i++) { - if ((mic[i] ^ s_0[i]) != a[i]) - return -1; - } - - return 0; -} + struct crypto_aead *tfm; + int err; + tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) + return tfm; -struct crypto_cipher *ieee80211_aes_key_setup_encrypt(const u8 key[]) -{ - struct crypto_cipher *tfm; + err = crypto_aead_setkey(tfm, key, WLAN_KEY_LEN_CCMP); + if (!err) + err = crypto_aead_setauthsize(tfm, IEEE80211_CCMP_MIC_LEN); + if (!err) + return tfm; - tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); - if (!IS_ERR(tfm)) - crypto_cipher_setkey(tfm, key, WLAN_KEY_LEN_CCMP); - - return tfm; + crypto_free_aead(tfm); + return ERR_PTR(err); } - -void ieee80211_aes_key_free(struct crypto_cipher *tfm) +void ieee80211_aes_key_free(struct crypto_aead *tfm) { - crypto_free_cipher(tfm); + crypto_free_aead(tfm); } diff --git a/net/mac80211/aes_ccm.h b/net/mac80211/aes_ccm.h index 5b7d744e2370..2c7ab1948a2e 100644 --- a/net/mac80211/aes_ccm.h +++ b/net/mac80211/aes_ccm.h @@ -12,13 +12,11 @@ #include <linux/crypto.h> -struct crypto_cipher *ieee80211_aes_key_setup_encrypt(const u8 key[]); -void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch, - u8 *data, size_t data_len, - u8 *cdata, u8 *mic); -int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch, - u8 *cdata, size_t data_len, - u8 *mic, u8 *data); -void ieee80211_aes_key_free(struct crypto_cipher *tfm); +struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[]); +void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, + u8 *data, size_t data_len, u8 *mic); +int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, + u8 *data, size_t data_len, u8 *mic); +void ieee80211_aes_key_free(struct crypto_aead *tfm); #endif /* AES_CCM_H */ diff --git a/net/mac80211/key.h b/net/mac80211/key.h index 036d57e76a5e..aaae0ed37004 100644 --- a/net/mac80211/key.h +++ b/net/mac80211/key.h @@ -83,7 +83,7 @@ struct ieee80211_key { * Management frames. */ u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_CCMP_PN_LEN]; - struct crypto_cipher *tfm; + struct crypto_aead *tfm; u32 replays; /* dot11RSNAStatsCCMPReplays */ } ccmp; struct { diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index c9edfcb7a13b..d65728220763 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -301,22 +301,16 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) } -static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, +static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad, int encrypted) { __le16 mask_fc; int a4_included, mgmt; u8 qos_tid; - u8 *b_0, *aad; - u16 data_len, len_a; + u16 len_a; unsigned int hdrlen; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; - memset(scratch, 0, 6 * AES_BLOCK_SIZE); - - b_0 = scratch + 3 * AES_BLOCK_SIZE; - aad = scratch + 4 * AES_BLOCK_SIZE; - /* * Mask FC: zero subtype b4 b5 b6 (if not mgmt) * Retry, PwrMgt, MoreData; set Protected @@ -338,20 +332,21 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, else qos_tid = 0; - data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN; - if (encrypted) - data_len -= IEEE80211_CCMP_MIC_LEN; + /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC + * mode authentication are not allowed to collide, yet both are derived + * from this vector b_0. We only set L := 1 here to indicate that the + * data size can be represented in (L+1) bytes. The CCM layer will take + * care of storing the data length in the top (L+1) bytes and setting + * and clearing the other bits as is required to derive the two IVs. + */ + b_0[0] = 0x1; - /* First block, b_0 */ - b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ /* Nonce: Nonce Flags | A2 | PN * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) */ b_0[1] = qos_tid | (mgmt << 4); memcpy(&b_0[2], hdr->addr2, ETH_ALEN); memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN); - /* l(m) */ - put_unaligned_be16(data_len, &b_0[14]); /* AAD (extra authenticate-only data) / masked 802.11 header * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ @@ -407,7 +402,8 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) u8 *pos; u8 pn[6]; u64 pn64; - u8 scratch[6 * AES_BLOCK_SIZE]; + u8 aad[2 * AES_BLOCK_SIZE]; + u8 b_0[AES_BLOCK_SIZE]; if (info->control.hw_key && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && @@ -460,9 +456,9 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) return 0; pos += IEEE80211_CCMP_HDR_LEN; - ccmp_special_blocks(skb, pn, scratch, 0); - ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, pos, len, - pos, skb_put(skb, IEEE80211_CCMP_MIC_LEN)); + ccmp_special_blocks(skb, pn, b_0, aad, 0); + ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len, + skb_put(skb, IEEE80211_CCMP_MIC_LEN)); return 0; } @@ -525,16 +521,16 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) } if (!(status->flag & RX_FLAG_DECRYPTED)) { - u8 scratch[6 * AES_BLOCK_SIZE]; + u8 aad[2 * AES_BLOCK_SIZE]; + u8 b_0[AES_BLOCK_SIZE]; /* hardware didn't decrypt/verify MIC */ - ccmp_special_blocks(skb, pn, scratch, 1); + ccmp_special_blocks(skb, pn, b_0, aad, 1); if (ieee80211_aes_ccm_decrypt( - key->u.ccmp.tfm, scratch, + key->u.ccmp.tfm, b_0, aad, skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN, data_len, - skb->data + skb->len - IEEE80211_CCMP_MIC_LEN, - skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN)) + skb->data + skb->len - IEEE80211_CCMP_MIC_LEN)) return RX_DROP_UNUSABLE; } |