On Thu, Sep 9, 2010 at 7:00 AM, Suresh Jayaraman <sjayaraman@xxxxxxx> wrote:
> On 09/08/2010 10:15 AM, shirishpargaonkar@xxxxxxxxx wrote:
>> From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
>>
>>
>> Allocate crypto hashing functions, ecurity descriptiors, and respective
>> contexts when a smb/tcp connection is established.
>> Release them when a tcp/smb connection is taken down.
>>
>> md5 and hmac-md5 are two crypto hashing functions that are used
>> throught the life of an smb/tcp connection by various functions that
>> calcualte signagure and ntlmv2 hash, HMAC etc.
>>
>>
>> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
>> ---
>> fs/cifs/cifsencrypt.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/cifs/cifsproto.h | 2 +
>> fs/cifs/connect.c | 16 +++++++++--
>> 3 files changed, 86 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
>> index 4bdcf13..4772c4d 100644
>> --- a/fs/cifs/cifsencrypt.c
>> +++ b/fs/cifs/cifsencrypt.c
>> @@ -369,3 +369,74 @@ void CalcNTLMv2_response(const struct cifsSesInfo *ses,
>> hmac_md5_final(v2_session_response, &context);
>> /* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
>> }
>> +
>> +void
>> +cifs_crypto_shash_release(struct TCP_Server_Info *server)
>> +{
>> + if (server->secmech.md5)
>> + crypto_free_shash(server->secmech.md5);
>> +
>> + if (server->secmech.hmacmd5)
>> + crypto_free_shash(server->secmech.hmacmd5);
>> +
>> + kfree(server->secmech.sdeschmacmd5);
>> +
>> + kfree(server->secmech.sdescmd5);
>> +}
>> +
>> +int
>> +cifs_crypto_shash_allocate(struct TCP_Server_Info *server)
>> +{
>> + int rc;
>> + unsigned int size;
>> +
>> + server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
>> + if (!server->secmech.hmacmd5 ||
>> + IS_ERR(server->secmech.hmacmd5)) {
>
> crypto_alloc_hash() seems to return a pointer to struct crypto_shash.
> Would it be sufficient to use IS_ERR() to check?
Suresh, not sure I understand, I check for NULL value of what
crypto_alloc_shash()
returns. IS_ERR() is what crypto code is using.
Copying crypto folks on the this thread.
>
> Also, instead of returning 1, we should use PTR_ERR() to propagate the
> appropriate error back. Otherwise, rc will always be 1 which gives
> little clue in case of error..
Done.
>
>
>> + cERROR(1, "could not allocate crypto hmacmd5\n");
>> + return 1;
>> + }
>> +
>> + server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
>> + if (!server->secmech.md5 || IS_ERR(server->secmech.md5)) {
>> + cERROR(1, "could not allocate crypto md5\n");
>> + rc = 1;
>
> ditto here..
Done here too.
>
>> + goto cifs_crypto_shash_allocate_ret1;
>
> nit: the goto labels could use better names..?
OK, will make them more meaningful in the next iteration.
>
>> + }
>
>> +
>> + size = sizeof(struct shash_desc) +
>> + crypto_shash_descsize(server->secmech.hmacmd5);
>> + server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
>> + if (!server->secmech.sdeschmacmd5) {
>> + cERROR(1, "cifs_crypto_shash_allocate: can't alloc hmacmd5\n");
>> + rc = -ENOMEM;
>> + goto cifs_crypto_shash_allocate_ret2;
>> + }
>> + server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
>> + server->secmech.sdeschmacmd5->shash.flags = 0x0;
>> +
>> +
>> + size = sizeof(struct shash_desc) +
>> + crypto_shash_descsize(server->secmech.md5);
>> + server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
>> + if (!server->secmech.sdescmd5) {
>> + cERROR(1, "cifs_crypto_shash_allocate: can't alloc md5\n");
>> + rc = -ENOMEM;
>> + goto cifs_crypto_shash_allocate_ret3;
>> + }
>> + server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
>> + server->secmech.sdescmd5->shash.flags = 0x0;
>> +
>> + return 0;
>> +
>> +cifs_crypto_shash_allocate_ret3:
>> + kfree(server->secmech.sdeschmacmd5);
>> +
>> +cifs_crypto_shash_allocate_ret2:
>> + crypto_free_shash(server->secmech.md5);
>> +
>> +cifs_crypto_shash_allocate_ret1:
>> + crypto_free_shash(server->secmech.hmacmd5);
>> +
>> + return rc;
>> +}
>> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
>> index eadf78c..fa3716c 100644
>> --- a/fs/cifs/cifsproto.h
>> +++ b/fs/cifs/cifsproto.h
>> @@ -368,6 +368,8 @@ extern int cifs_calculate_mac_key(struct session_key *key, const char *rn,
>> extern void CalcNTLMv2_response(const struct cifsSesInfo *, char *);
>> extern void setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
>> const struct nls_table *);
>> +extern int cifs_crypto_shash_allocate(struct TCP_Server_Info *);
>> +extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
>> #ifdef CONFIG_CIFS_WEAK_PW_HASH
>> extern void calc_lanman_hash(const char *password, const char *cryptkey,
>> bool encrypt, char *lnm_session_key);
>> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
>> index 0ea52e9..f5369e7 100644
>> --- a/fs/cifs/connect.c
>> +++ b/fs/cifs/connect.c
>> @@ -1520,6 +1520,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server)
>> server->tcpStatus = CifsExiting;
>> spin_unlock(&GlobalMid_Lock);
>>
>> + cifs_crypto_shash_release(server);
>> cifs_fscache_release_client_cookie(server);
>>
>> task = xchg(&server->tsk, NULL);
>> @@ -1574,10 +1575,16 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
>> goto out_err;
>> }
>>
>> + rc = cifs_crypto_shash_allocate(tcp_ses);
>> + if (rc) {
>> + cERROR(1, "could not setup hash structures rc %d", rc);
>> + goto out_err;
>> + }
>> +
>> tcp_ses->hostname = extract_hostname(volume_info->UNC);
>> if (IS_ERR(tcp_ses->hostname)) {
>> rc = PTR_ERR(tcp_ses->hostname);
>> - goto out_err;
>> + goto out_err2;
>> }
>>
>> tcp_ses->noblocksnd = volume_info->noblocksnd;
>> @@ -1618,7 +1625,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
>> }
>> if (rc < 0) {
>> cERROR(1, "Error connecting to socket. Aborting operation");
>> - goto out_err;
>> + goto out_err2;
>> }
>>
>> /*
>> @@ -1632,7 +1639,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
>> rc = PTR_ERR(tcp_ses->tsk);
>> cERROR(1, "error %d create cifsd thread", rc);
>> module_put(THIS_MODULE);
>> - goto out_err;
>> + goto out_err2;
>> }
>>
>> /* thread spawned, put it on the list */
>> @@ -1644,6 +1651,9 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
>>
>> return tcp_ses;
>>
>> +out_err2:
>> + cifs_crypto_shash_release(tcp_ses);
>> +
>> out_err:
>> if (tcp_ses) {
>> if (!IS_ERR(tcp_ses->hostname))
>
>
> --
> Suresh Jayaraman
>
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