mac80111: Add BIP-GMAC-128 and BIP-GMAC-256 ciphers

This allows mac80211 to configure BIP-GMAC-128 and BIP-GMAC-256 to the
driver and also use software-implementation within mac80211 when the
driver does not support this with hardware accelaration.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/net/mac80211/aes_gmac.c b/net/mac80211/aes_gmac.c
new file mode 100644
index 000000000000..1c72edcb0083
--- /dev/null
+++ b/net/mac80211/aes_gmac.c
@@ -0,0 +1,84 @@
+/*
+ * AES-GMAC for IEEE 802.11 BIP-GMAC-128 and BIP-GMAC-256
+ * Copyright 2015, Qualcomm Atheros, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/err.h>
+#include <crypto/aes.h>
+
+#include <net/mac80211.h>
+#include "key.h"
+#include "aes_gmac.h"
+
+#define GMAC_MIC_LEN 16
+#define GMAC_NONCE_LEN 12
+#define AAD_LEN 20
+
+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[3], ct[1];
+	char aead_req_data[sizeof(struct aead_request) +
+			   crypto_aead_reqsize(tfm)]
+		__aligned(__alignof__(struct aead_request));
+	struct aead_request *aead_req = (void *)aead_req_data;
+	u8 zero[GMAC_MIC_LEN], iv[AES_BLOCK_SIZE];
+
+	if (data_len < GMAC_MIC_LEN)
+		return -EINVAL;
+
+	memset(aead_req, 0, sizeof(aead_req_data));
+
+	memset(zero, 0, GMAC_MIC_LEN);
+	sg_init_table(sg, 3);
+	sg_set_buf(&sg[0], aad, AAD_LEN);
+	sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN);
+	sg_set_buf(&sg[2], zero, 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;
+
+	sg_init_table(ct, 1);
+	sg_set_buf(&ct[0], mic, GMAC_MIC_LEN);
+
+	aead_request_set_tfm(aead_req, tfm);
+	aead_request_set_assoc(aead_req, sg, AAD_LEN + data_len);
+	aead_request_set_crypt(aead_req, NULL, ct, 0, iv);
+
+	crypto_aead_encrypt(aead_req);
+
+	return 0;
+}
+
+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)
+		return tfm;
+	if (!err)
+		err = crypto_aead_setauthsize(tfm, GMAC_MIC_LEN);
+
+	crypto_free_aead(tfm);
+	return ERR_PTR(err);
+}
+
+void ieee80211_aes_gmac_key_free(struct crypto_aead *tfm)
+{
+	crypto_free_aead(tfm);
+}