cifsd: add support for AES256 encryption

Now that 256 bit encryption can be negotiated, update
names of the nonces to match the updated official protocol
documentation (e.g. AES_GCM_NONCE instead of AES_128GCM_NONCE)
since they apply to both 128 bit and 256 bit encryption.
update smb encryption code to set 32 byte key length and to
set gcm256/ccm256 when requested on mount.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Namjae Jeon 2021-05-06 11:43:37 +09:00 committed by Steve French
parent 1fca8038e9
commit 5a0ca77005
6 changed files with 68 additions and 34 deletions

View file

@ -835,7 +835,8 @@ static int generate_key(struct ksmbd_session *sess, struct kvec label,
{
unsigned char zero = 0x0;
__u8 i[4] = {0, 0, 0, 1};
__u8 L[4] = {0, 0, 0, 128};
__u8 L128[4] = {0, 0, 0, 128};
__u8 L256[4] = {0, 0, 1, 0};
int rc = -EINVAL;
unsigned char prfhash[SMB2_HMACSHA256_SIZE];
unsigned char *hashptr = prfhash;
@ -890,7 +891,11 @@ static int generate_key(struct ksmbd_session *sess, struct kvec label,
goto smb3signkey_ret;
}
rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L, 4);
if (sess->conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
sess->conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM)
rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L256, 4);
else
rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L128, 4);
if (rc) {
ksmbd_debug(AUTH, "could not update with L\n");
goto smb3signkey_ret;
@ -981,24 +986,33 @@ static int generate_smb3encryptionkey(struct ksmbd_session *sess,
rc = generate_key(sess, ptwin->encryption.label,
ptwin->encryption.context, sess->smb3encryptionkey,
SMB3_SIGN_KEY_SIZE);
SMB3_ENC_DEC_KEY_SIZE);
if (rc)
return rc;
rc = generate_key(sess, ptwin->decryption.label,
ptwin->decryption.context,
sess->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
sess->smb3decryptionkey, SMB3_ENC_DEC_KEY_SIZE);
if (rc)
return rc;
ksmbd_debug(AUTH, "dumping generated AES encryption keys\n");
ksmbd_debug(AUTH, "Cipher type %d\n", sess->conn->cipher_type);
ksmbd_debug(AUTH, "Session Id %llu\n", sess->id);
ksmbd_debug(AUTH, "Session Key %*ph\n",
SMB2_NTLMV2_SESSKEY_SIZE, sess->sess_key);
ksmbd_debug(AUTH, "ServerIn Key %*ph\n",
SMB3_SIGN_KEY_SIZE, sess->smb3encryptionkey);
ksmbd_debug(AUTH, "ServerOut Key %*ph\n",
SMB3_SIGN_KEY_SIZE, sess->smb3decryptionkey);
if (sess->conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
sess->conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM) {
ksmbd_debug(AUTH, "ServerIn Key %*ph\n",
SMB3_GCM256_CRYPTKEY_SIZE, sess->smb3encryptionkey);
ksmbd_debug(AUTH, "ServerOut Key %*ph\n",
SMB3_GCM256_CRYPTKEY_SIZE, sess->smb3decryptionkey);
} else {
ksmbd_debug(AUTH, "ServerIn Key %*ph\n",
SMB3_GCM128_CRYPTKEY_SIZE, sess->smb3encryptionkey);
ksmbd_debug(AUTH, "ServerOut Key %*ph\n",
SMB3_GCM128_CRYPTKEY_SIZE, sess->smb3decryptionkey);
}
return rc;
}
@ -1136,7 +1150,7 @@ static int ksmbd_get_encryption_key(struct ksmbd_conn *conn, __u64 ses_id,
ses_enc_key = enc ? sess->smb3encryptionkey :
sess->smb3decryptionkey;
memcpy(key, ses_enc_key, SMB3_SIGN_KEY_SIZE);
memcpy(key, ses_enc_key, SMB3_ENC_DEC_KEY_SIZE);
return 0;
}
@ -1224,7 +1238,7 @@ int ksmbd_crypt_message(struct ksmbd_conn *conn, struct kvec *iov,
int rc = 0;
struct scatterlist *sg;
u8 sign[SMB2_SIGNATURE_SIZE] = {};
u8 key[SMB3_SIGN_KEY_SIZE];
u8 key[SMB3_ENC_DEC_KEY_SIZE];
struct aead_request *req;
char *iv;
unsigned int iv_len;
@ -1241,7 +1255,8 @@ int ksmbd_crypt_message(struct ksmbd_conn *conn, struct kvec *iov,
return 0;
}
if (conn->cipher_type == SMB2_ENCRYPTION_AES128_GCM)
if (conn->cipher_type == SMB2_ENCRYPTION_AES128_GCM ||
conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM)
ctx = ksmbd_crypto_ctx_find_gcm();
else
ctx = ksmbd_crypto_ctx_find_ccm();
@ -1250,12 +1265,17 @@ int ksmbd_crypt_message(struct ksmbd_conn *conn, struct kvec *iov,
return -EINVAL;
}
if (conn->cipher_type == SMB2_ENCRYPTION_AES128_GCM)
if (conn->cipher_type == SMB2_ENCRYPTION_AES128_GCM ||
conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM)
tfm = CRYPTO_GCM(ctx);
else
tfm = CRYPTO_CCM(ctx);
rc = crypto_aead_setkey(tfm, key, SMB3_SIGN_KEY_SIZE);
if (conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM)
rc = crypto_aead_setkey(tfm, key, SMB3_GCM256_CRYPTKEY_SIZE);
else
rc = crypto_aead_setkey(tfm, key, SMB3_GCM128_CRYPTKEY_SIZE);
if (rc) {
ksmbd_err("Failed to set aead key %d\n", rc);
goto free_ctx;
@ -1294,11 +1314,12 @@ int ksmbd_crypt_message(struct ksmbd_conn *conn, struct kvec *iov,
goto free_sg;
}
if (conn->cipher_type == SMB2_ENCRYPTION_AES128_GCM) {
memcpy(iv, (char *)tr_hdr->Nonce, SMB3_AES128GCM_NONCE);
if (conn->cipher_type == SMB2_ENCRYPTION_AES128_GCM ||
conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM) {
memcpy(iv, (char *)tr_hdr->Nonce, SMB3_AES_GCM_NONCE);
} else {
iv[0] = 3;
memcpy(iv + 1, (char *)tr_hdr->Nonce, SMB3_AES128CCM_NONCE);
memcpy(iv + 1, (char *)tr_hdr->Nonce, SMB3_AES_CCM_NONCE);
}
aead_request_set_crypt(req, sg, sg, crypt_len, iv);

View file

@ -42,10 +42,10 @@ static struct crypto_aead *alloc_aead(int id)
struct crypto_aead *tfm = NULL;
switch (id) {
case CRYPTO_AEAD_AES128_GCM:
case CRYPTO_AEAD_AES_GCM:
tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
break;
case CRYPTO_AEAD_AES128_CCM:
case CRYPTO_AEAD_AES_CCM:
tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
break;
default:
@ -248,12 +248,12 @@ static struct ksmbd_crypto_ctx *____crypto_aead_ctx_find(int id)
struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_gcm(void)
{
return ____crypto_aead_ctx_find(CRYPTO_AEAD_AES128_GCM);
return ____crypto_aead_ctx_find(CRYPTO_AEAD_AES_GCM);
}
struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_ccm(void)
{
return ____crypto_aead_ctx_find(CRYPTO_AEAD_AES128_CCM);
return ____crypto_aead_ctx_find(CRYPTO_AEAD_AES_CCM);
}
void ksmbd_crypto_destroy(void)

View file

@ -21,8 +21,8 @@ enum {
};
enum {
CRYPTO_AEAD_AES128_GCM = 16,
CRYPTO_AEAD_AES128_CCM,
CRYPTO_AEAD_AES_GCM = 16,
CRYPTO_AEAD_AES_CCM,
CRYPTO_AEAD_MAX,
};
@ -55,8 +55,8 @@ struct ksmbd_crypto_ctx {
#define CRYPTO_MD4_TFM(c) ((c)->desc[CRYPTO_SHASH_MD4]->tfm)
#define CRYPTO_MD5_TFM(c) ((c)->desc[CRYPTO_SHASH_MD5]->tfm)
#define CRYPTO_GCM(c) ((c)->ccmaes[CRYPTO_AEAD_AES128_GCM])
#define CRYPTO_CCM(c) ((c)->ccmaes[CRYPTO_AEAD_AES128_CCM])
#define CRYPTO_GCM(c) ((c)->ccmaes[CRYPTO_AEAD_AES_GCM])
#define CRYPTO_CCM(c) ((c)->ccmaes[CRYPTO_AEAD_AES_CCM])
void ksmbd_release_crypto_ctx(struct ksmbd_crypto_ctx *ctx);

View file

@ -56,8 +56,8 @@ struct ksmbd_session {
__u8 smb3encryptionkey[SMB3_SIGN_KEY_SIZE];
__u8 smb3decryptionkey[SMB3_SIGN_KEY_SIZE];
__u8 smb3encryptionkey[SMB3_ENC_DEC_KEY_SIZE];
__u8 smb3decryptionkey[SMB3_ENC_DEC_KEY_SIZE];
__u8 smb3signingkey[SMB3_SIGN_KEY_SIZE];
struct list_head sessions_entry;

View file

@ -904,7 +904,9 @@ static int decode_encrypt_ctxt(struct ksmbd_conn *conn,
for (i = 0; i < cph_cnt; i++) {
if (pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES128_GCM ||
pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES128_CCM) {
pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES128_CCM ||
pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES256_CCM ||
pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES256_GCM) {
ksmbd_debug(SMB, "Cipher ID = 0x%x\n",
pneg_ctxt->Ciphers[i]);
conn->cipher_type = pneg_ctxt->Ciphers[i];
@ -7979,10 +7981,11 @@ static void fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, char *old_buf,
tr_hdr->ProtocolId = SMB2_TRANSFORM_PROTO_NUM;
tr_hdr->OriginalMessageSize = cpu_to_le32(orig_len);
tr_hdr->Flags = cpu_to_le16(0x01);
if (cipher_type == SMB2_ENCRYPTION_AES128_GCM)
get_random_bytes(&tr_hdr->Nonce, SMB3_AES128GCM_NONCE);
if (cipher_type == SMB2_ENCRYPTION_AES128_GCM ||
cipher_type == SMB2_ENCRYPTION_AES256_GCM)
get_random_bytes(&tr_hdr->Nonce, SMB3_AES_GCM_NONCE);
else
get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CCM_NONCE);
get_random_bytes(&tr_hdr->Nonce, SMB3_AES_CCM_NONCE);
memcpy(&tr_hdr->SessionId, &hdr->SessionId, 8);
inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - 4);
inc_rfc1001_len(tr_hdr, orig_len);

View file

@ -77,6 +77,13 @@
#define SMB2_SIGNATURE_SIZE 16
#define SMB2_HMACSHA256_SIZE 32
#define SMB2_CMACAES_SIZE 16
#define SMB3_GCM128_CRYPTKEY_SIZE 16
#define SMB3_GCM256_CRYPTKEY_SIZE 32
/*
* Size of the smb3 encryption/decryption keys
*/
#define SMB3_ENC_DEC_KEY_SIZE 32
/*
* Size of the smb3 signing key
@ -151,8 +158,8 @@ struct smb2_pdu {
__le16 StructureSize2; /* size of wct area (varies, request specific) */
} __packed;
#define SMB3_AES128CCM_NONCE 11
#define SMB3_AES128GCM_NONCE 12
#define SMB3_AES_CCM_NONCE 11
#define SMB3_AES_GCM_NONCE 12
struct smb2_transform_hdr {
__be32 smb2_buf_length; /* big endian on wire */
@ -283,13 +290,16 @@ struct smb2_preauth_neg_context {
/* Encryption Algorithms Ciphers */
#define SMB2_ENCRYPTION_AES128_CCM cpu_to_le16(0x0001)
#define SMB2_ENCRYPTION_AES128_GCM cpu_to_le16(0x0002)
#define SMB2_ENCRYPTION_AES256_CCM cpu_to_le16(0x0003)
#define SMB2_ENCRYPTION_AES256_GCM cpu_to_le16(0x0004)
struct smb2_encryption_neg_context {
__le16 ContextType; /* 2 */
__le16 DataLength;
__le32 Reserved;
__le16 CipherCount; /* AES-128-GCM and AES-128-CCM */
__le16 Ciphers[1]; /* Ciphers[0] since only one used now */
/* CipherCount usally 2, but can be 3 when AES256-GCM enabled */
__le16 CipherCount; /* AES-128-GCM and AES-128-CCM by default */
__le16 Ciphers[1];
} __packed;
#define SMB3_COMPRESS_NONE cpu_to_le16(0x0000)