mac80111: Add GCMP and GCMP-256 ciphers

This allows mac80211 to configure GCMP and GCMP-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>
[remove a spurious newline]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/net/mac80211/aes_gcm.c b/net/mac80211/aes_gcm.c
new file mode 100644
index 000000000000..c2bf6698d738
--- /dev/null
+++ b/net/mac80211/aes_gcm.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2014-2015, 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_gcm.h"
+
+void ieee80211_aes_gcm_encrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
+			       u8 *data, size_t data_len, u8 *mic)
+{
+	struct scatterlist assoc, pt, ct[2];
+
+	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;
+
+	memset(aead_req, 0, sizeof(aead_req_data));
+
+	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_GCMP_MIC_LEN);
+
+	aead_request_set_tfm(aead_req, tfm);
+	aead_request_set_assoc(aead_req, &assoc, assoc.length);
+	aead_request_set_crypt(aead_req, &pt, ct, data_len, j_0);
+
+	crypto_aead_encrypt(aead_req);
+}
+
+int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
+			      u8 *data, size_t data_len, u8 *mic)
+{
+	struct scatterlist assoc, pt, ct[2];
+	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;
+
+	if (data_len == 0)
+		return -EINVAL;
+
+	memset(aead_req, 0, sizeof(aead_req_data));
+
+	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_GCMP_MIC_LEN);
+
+	aead_request_set_tfm(aead_req, tfm);
+	aead_request_set_assoc(aead_req, &assoc, assoc.length);
+	aead_request_set_crypt(aead_req, ct, &pt,
+			       data_len + IEEE80211_GCMP_MIC_LEN, j_0);
+
+	return crypto_aead_decrypt(aead_req);
+}
+
+struct crypto_aead *ieee80211_aes_gcm_key_setup_encrypt(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, IEEE80211_GCMP_MIC_LEN);
+	if (!err)
+		return tfm;
+
+	crypto_free_aead(tfm);
+	return ERR_PTR(err);
+}
+
+void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm)
+{
+	crypto_free_aead(tfm);
+}