// SPDX-License-Identifier: GPL-2.0-only /* * AES-GMAC for IEEE 802.11 BIP-GMAC-128 and BIP-GMAC-256 * Copyright 2015, Qualcomm Atheros, Inc. */ #include <linux/kernel.h> #include <linux/types.h> #include <linux/err.h> #include <crypto/aead.h> #include <crypto/aes.h> #include <net/mac80211.h> #include "key.h" #include "aes_gmac.h" int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce, const u8 *data, size_t data_len, u8 *mic) { struct scatterlist sg[5]; u8 *zero, *__aad, iv[AES_BLOCK_SIZE]; struct aead_request *aead_req; int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm); const __le16 *fc; int ret; if (data_len < GMAC_MIC_LEN) return -EINVAL; aead_req = kzalloc(reqsize + GMAC_MIC_LEN + GMAC_AAD_LEN, GFP_ATOMIC); if (!aead_req) return -ENOMEM; zero = (u8 *)aead_req + reqsize; __aad = zero + GMAC_MIC_LEN; memcpy(__aad, aad, GMAC_AAD_LEN); fc = (const __le16 *)aad; if (ieee80211_is_beacon(*fc)) { /* mask Timestamp field to zero */ sg_init_table(sg, 5); sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN); sg_set_buf(&sg[1], zero, 8); sg_set_buf(&sg[2], data + 8, data_len - 8 - GMAC_MIC_LEN); sg_set_buf(&sg[3], zero, GMAC_MIC_LEN); sg_set_buf(&sg[4], mic, GMAC_MIC_LEN); } else { sg_init_table(sg, 4); sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN); sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN); sg_set_buf(&sg[2], zero, GMAC_MIC_LEN); sg_set_buf(&sg[3], mic, GMAC_MIC_LEN); } memcpy(iv, nonce, GMAC_NONCE_LEN); memset(iv + GMAC_NONCE_LEN, 0, sizeof(iv) - GMAC_NONCE_LEN); iv[AES_BLOCK_SIZE - 1] = 0x01; aead_request_set_tfm(aead_req, tfm); aead_request_set_crypt(aead_req, sg, sg, 0, iv); aead_request_set_ad(aead_req, GMAC_AAD_LEN + data_len); ret = crypto_aead_encrypt(aead_req); kfree_sensitive(aead_req); return ret; } struct crypto_aead *ieee80211_aes_gmac_key_setup(const u8 key[], size_t key_len) { struct crypto_aead *tfm; int err; tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(tfm)) return tfm; err = crypto_aead_setkey(tfm, key, key_len); if (!err) err = crypto_aead_setauthsize(tfm, GMAC_MIC_LEN); if (!err) return tfm; crypto_free_aead(tfm); return ERR_PTR(err); } void ieee80211_aes_gmac_key_free(struct crypto_aead *tfm) { crypto_free_aead(tfm); }