On Thu, 9 Sep 2010 13:12:40 -0500
[email protected] wrote:
> From: Shirish Pargaonkar <[email protected]>
>
> To calculate ntlmv2 response we need ti/av pair blob.
>
> For sec mech like ntlmssp, the blob is plucked from type 2 response from
> the server. From this blob, netbios name of the domain is retrieved,
> if user has not already provided, to be included in the Target String
> as part of ntlmv2 hash calculations.
>
> For sec mech like ntlmv2, create a minimal, two av pair blob.
>
> The allocated blob is freed in case of error. In case there is no error,
> this blob is used in calculating ntlmv2 response (in CalcNTLMv2_response)
> and is also copied on the response to the server, and then freed.
>
> The type 3 ntlmssp response is prepared on a buffer,
> 5 * sizeof of struct _AUTHENTICATE_MESSAGE, an empirical value large
> enough to hold _AUTHENTICATE_MESSAGE plus a blob with max possible
> 10 values as part of ntlmv2 response and lmv2 keys and domain, user,
> workstation names etc.
>
> Also, kerberos gets selected as a default mechanism if server supports it,
> over the other security mechanisms.
>
> The reason mac_key was changed to session key is, this structure does not hold
> message authentication code, it holds the session key (for ntlmv2, ntlmv1
> etc.).
> mac is generated as a signature in cifs_calc* functions.
>
>
> Signed-off-by: Shirish Pargaonkar <[email protected]>
> ---
> fs/cifs/cifsencrypt.c | 58 +++++++++++++++++++++++-------
> fs/cifs/cifsglob.h | 4 +-
> fs/cifs/cifsproto.h | 6 ++--
> fs/cifs/cifssmb.c | 16 +++++----
> fs/cifs/sess.c | 93 ++++++++++++++++++++++++++++++++++--------------
> fs/cifs/transport.c | 6 ++--
> 6 files changed, 128 insertions(+), 55 deletions(-)
>
> diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
> index 346fb64..7e15cd0 100644
> --- a/fs/cifs/cifsencrypt.c
> +++ b/fs/cifs/cifsencrypt.c
> @@ -43,7 +43,8 @@ extern void SMBencrypt(unsigned char *passwd, const
> unsigned char *c8,
> unsigned char *p24);
>
> static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
> - const struct mac_key *key, char *signature)
> + const struct session_key *key,
> + char *signature)
> {
> struct MD5Context context;
>
> @@ -79,7 +80,7 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct
> TCP_Server_Info *server,
> server->sequence_number++;
> spin_unlock(&GlobalMid_Lock);
>
> - rc = cifs_calculate_signature(cifs_pdu, &server->mac_signing_key,
> + rc = cifs_calculate_signature(cifs_pdu, &server->session_key,
> smb_signature);
> if (rc)
> memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
> @@ -90,7 +91,7 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct
> TCP_Server_Info *server,
> }
>
> static int cifs_calc_signature2(const struct kvec *iov, int n_vec,
> - const struct mac_key *key, char *signature)
> + const struct session_key *key, char *signature)
> {
> struct MD5Context context;
> int i;
> @@ -146,7 +147,7 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct
> TCP_Server_Info *server,
> server->sequence_number++;
> spin_unlock(&GlobalMid_Lock);
>
> - rc = cifs_calc_signature2(iov, n_vec, &server->mac_signing_key,
> + rc = cifs_calc_signature2(iov, n_vec, &server->session_key,
> smb_signature);
> if (rc)
> memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
> @@ -157,14 +158,14 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct
> TCP_Server_Info *server,
> }
>
> int cifs_verify_signature(struct smb_hdr *cifs_pdu,
> - const struct mac_key *mac_key,
> + const struct session_key *session_key,
> __u32 expected_sequence_number)
> {
> unsigned int rc;
> char server_response_sig[8];
> char what_we_think_sig_should_be[20];
>
> - if ((cifs_pdu == NULL) || (mac_key == NULL))
> + if (cifs_pdu == NULL || session_key == NULL)
> return -EINVAL;
>
> if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
> @@ -193,7 +194,7 @@ int cifs_verify_signature(struct smb_hdr *cifs_pdu,
> cpu_to_le32(expected_sequence_number);
> cifs_pdu->Signature.Sequence.Reserved = 0;
>
> - rc = cifs_calculate_signature(cifs_pdu, mac_key,
> + rc = cifs_calculate_signature(cifs_pdu, session_key,
> what_we_think_sig_should_be);
>
> if (rc)
> @@ -210,7 +211,7 @@ int cifs_verify_signature(struct smb_hdr *cifs_pdu,
> }
>
> /* We fill in key by putting in 40 byte array which was allocated by caller
> */
> -int cifs_calculate_mac_key(struct mac_key *key, const char *rn,
> +int cifs_calculate_session_key(struct session_key *key, const char *rn,
> const char *password)
> {
> char temp_key[16];
> @@ -395,7 +396,8 @@ calc_exit_2:
> return rc;
> }
>
> -void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
> +int
> +setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
> const struct nls_table *nls_cp)
> {
> int rc;
> @@ -408,20 +410,46 @@ void setup_ntlmv2_rsp(struct cifsSesInfo *ses, char
> *resp_buf,
> get_random_bytes(&buf->client_chal, sizeof(buf->client_chal));
> buf->reserved2 = 0;
>
> + if (ses->server->secType == RawNTLMSSP) {
> + if (!ses->domainName) {
> + rc = find_domain_name(ses);
> + if (rc) {
> + cERROR(1, "error %d finding domain name", rc);
> + goto setup_ntlmv2_rsp_ret;
> + }
> + }
> + } else {
> + rc = build_avpair_blob(ses);
> + if (rc) {
> + cERROR(1, "error %d building av pair blob", rc);
> + return rc;
> + }
> + }
> +
> /* calculate buf->ntlmv2_hash */
> rc = calc_ntlmv2_hash(ses, nls_cp);
> - if (rc)
> + if (rc) {
> cERROR(1, "could not get v2 hash rc %d", rc);
> + goto setup_ntlmv2_rsp_ret;
> + }
> CalcNTLMv2_response(ses, resp_buf);
>
> /* now calculate the MAC key for NTLMv2 */
> hmac_md5_init_limK_to_64(ses->server->ntlmv2_hash, 16, &context);
> hmac_md5_update(resp_buf, 16, &context);
> - hmac_md5_final(ses->server->mac_signing_key.data.ntlmv2.key, &context);
> + hmac_md5_final(ses->server->session_key.data.ntlmv2.key, &context);
>
> - memcpy(&ses->server->mac_signing_key.data.ntlmv2.resp, resp_buf,
> + memcpy(&ses->server->session_key.data.ntlmv2.resp, resp_buf,
> sizeof(struct ntlmv2_resp));
> - ses->server->mac_signing_key.len = 16 + sizeof(struct ntlmv2_resp);
> + ses->server->session_key.len = 16 + sizeof(struct ntlmv2_resp);
> +
> + return 0;
> +
> +setup_ntlmv2_rsp_ret:
> + kfree(ses->tiblob);
> + ses->tilen = 0;
> +
> + return rc;
> }
>
> void CalcNTLMv2_response(const struct cifsSesInfo *ses,
> @@ -435,6 +463,10 @@ void CalcNTLMv2_response(const struct cifsSesInfo *ses,
> hmac_md5_update(v2_session_response+8,
> sizeof(struct ntlmv2_resp) - 8, &context);
>
> + if (ses->tilen)
> + hmac_md5_update(ses->tiblob,
> + ses->tilen, &context);
> +
> hmac_md5_final(v2_session_response, &context);
> /* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
> }
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 2bfe682..c68f31c 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -97,7 +97,7 @@ enum protocolEnum {
> /* Netbios frames protocol not supported at this time */
> };
>
> -struct mac_key {
> +struct session_key {
> unsigned int len;
> union {
> char ntlm[CIFS_SESS_KEY_SIZE + 16];
> @@ -182,7 +182,7 @@ struct TCP_Server_Info {
> /* 16th byte of RFC1001 workstation name is always null */
> char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL];
> __u32 sequence_number; /* needed for CIFS PDU signature */
> - struct mac_key mac_signing_key;
> + struct session_key session_key;
> char ntlmv2_hash[16];
> unsigned long lstrp; /* when we got last response from this server */
> u16 dialect; /* dialect index that server chose */
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index 1d60c65..c155479 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -362,12 +362,12 @@ extern int cifs_sign_smb(struct smb_hdr *, struct
> TCP_Server_Info *, __u32 *);
> extern int cifs_sign_smb2(struct kvec *iov, int n_vec, struct
> TCP_Server_Info *,
> __u32 *);
> extern int cifs_verify_signature(struct smb_hdr *,
> - const struct mac_key *mac_key,
> + const struct session_key *session_key,
> __u32 expected_sequence_number);
> -extern int cifs_calculate_mac_key(struct mac_key *key, const char *rn,
> +extern int cifs_calculate_session_key(struct session_key *key, const char
> *rn,
> const char *pass);
> extern void CalcNTLMv2_response(const struct cifsSesInfo *, char *);
> -extern void setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
> +extern int setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
> const struct nls_table *);
> #ifdef CONFIG_CIFS_WEAK_PW_HASH
> extern void calc_lanman_hash(const char *password, const char *cryptkey,
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index c65c341..13c854e 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -603,13 +603,15 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo
> *ses)
> rc = 0;
> else
> rc = -EINVAL;
> -
> - if (server->sec_kerberos || server->sec_mskerberos)
> - server->secType = Kerberos;
> - else if (server->sec_ntlmssp)
> - server->secType = RawNTLMSSP;
> - else
> - rc = -EOPNOTSUPP;
> + if (server->secType == Kerberos) {
> + if (!server->sec_kerberos &&
> + !server->sec_mskerberos)
> + rc = -EOPNOTSUPP;
> + } else if (server->secType == RawNTLMSSP) {
> + if (!server->sec_ntlmssp)
> + rc = -EOPNOTSUPP;
> + } else
> + rc = -EOPNOTSUPP;
^^^^^^^^^^^^^^
This was a separate patch before. It probably ought to remain
one.
> }
> } else
> server->capabilities &= ~CAP_EXTENDED_SECURITY;
> diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
> index 2de5f08..8f44fde 100644
> --- a/fs/cifs/sess.c
> +++ b/fs/cifs/sess.c
> @@ -440,7 +440,7 @@ static void build_ntlmssp_negotiate_blob(unsigned char
> *pbuffer,
> /* BB is NTLMV2 session security format easier to use here? */
> flags = NTLMSSP_NEGOTIATE_56 | NTLMSSP_REQUEST_TARGET |
> NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
> - NTLMSSP_NEGOTIATE_NT_ONLY | NTLMSSP_NEGOTIATE_NTLM;
> + NTLMSSP_NEGOTIATE_NTLM;
> if (ses->server->secMode &
> (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
> flags |= NTLMSSP_NEGOTIATE_SIGN;
> @@ -466,10 +466,12 @@ static int build_ntlmssp_auth_blob(unsigned char
> *pbuffer,
> struct cifsSesInfo *ses,
> const struct nls_table *nls_cp, bool first)
> {
> + int rc;
> + unsigned int size;
> AUTHENTICATE_MESSAGE *sec_blob = (AUTHENTICATE_MESSAGE *)pbuffer;
> __u32 flags;
> unsigned char *tmp;
> - char ntlm_session_key[CIFS_SESS_KEY_SIZE];
> + struct ntlmv2_resp ntlmv2_response = {};
>
> memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
> sec_blob->MessageType = NtLmAuthenticate;
> @@ -477,7 +479,7 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> flags = NTLMSSP_NEGOTIATE_56 |
> NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
> NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
> - NTLMSSP_NEGOTIATE_NT_ONLY | NTLMSSP_NEGOTIATE_NTLM;
> + NTLMSSP_NEGOTIATE_NTLM;
> if (ses->server->secMode &
> (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
> flags |= NTLMSSP_NEGOTIATE_SIGN;
> @@ -492,19 +494,26 @@ static int build_ntlmssp_auth_blob(unsigned char
> *pbuffer,
> sec_blob->LmChallengeResponse.Length = 0;
> sec_blob->LmChallengeResponse.MaximumLength = 0;
>
> - /* calculate session key, BB what about adding similar ntlmv2 path? */
> - SMBNTencrypt(ses->password, ses->server->cryptKey, ntlm_session_key);
> - if (first)
> - cifs_calculate_mac_key(&ses->server->mac_signing_key,
> - ntlm_session_key, ses->password);
> -
> - memcpy(tmp, ntlm_session_key, CIFS_SESS_KEY_SIZE);
> sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
> - sec_blob->NtChallengeResponse.Length = cpu_to_le16(CIFS_SESS_KEY_SIZE);
> - sec_blob->NtChallengeResponse.MaximumLength =
> - cpu_to_le16(CIFS_SESS_KEY_SIZE);
> + rc = setup_ntlmv2_rsp(ses, (char *)&ntlmv2_response, nls_cp);
> + if (rc) {
> + cERROR(1, "Error %d during NTLMSSP authentication", rc);
> + goto setup_ntlmv2_ret;
> + }
> + size = sizeof(struct ntlmv2_resp);
> + memcpy(tmp, (char *)&ntlmv2_response, size);
> + tmp += size;
> + if (ses->tilen > 0) {
> + memcpy(tmp, ses->tiblob, ses->tilen);
> + tmp += ses->tilen;
> + }
>
> - tmp += CIFS_SESS_KEY_SIZE;
> + sec_blob->NtChallengeResponse.Length = cpu_to_le16(size +
> + ses->tilen);
> + sec_blob->NtChallengeResponse.MaximumLength =
> + cpu_to_le16(size + ses->tilen);
> + kfree(ses->tiblob);
> + ses->tilen = 0;
>
> if (ses->domainName == NULL) {
> sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
> @@ -516,7 +525,6 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> len = cifs_strtoUCS((__le16 *)tmp, ses->domainName,
> MAX_USERNAME_SIZE, nls_cp);
> len *= 2; /* unicode is 2 bytes each */
> - len += 2; /* trailing null */
> sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
> sec_blob->DomainName.Length = cpu_to_le16(len);
> sec_blob->DomainName.MaximumLength = cpu_to_le16(len);
> @@ -533,7 +541,6 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> len = cifs_strtoUCS((__le16 *)tmp, ses->userName,
> MAX_USERNAME_SIZE, nls_cp);
> len *= 2; /* unicode is 2 bytes each */
> - len += 2; /* trailing null */
> sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
> sec_blob->UserName.Length = cpu_to_le16(len);
> sec_blob->UserName.MaximumLength = cpu_to_le16(len);
> @@ -548,6 +555,8 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
> sec_blob->SessionKey.Length = 0;
> sec_blob->SessionKey.MaximumLength = 0;
> +
> +setup_ntlmv2_ret:
> return tmp - pbuffer;
> }
>
> @@ -561,15 +570,14 @@ static void setup_ntlmssp_neg_req(SESSION_SETUP_ANDX
> *pSMB,
> return;
> }
>
> -static int setup_ntlmssp_auth_req(SESSION_SETUP_ANDX *pSMB,
> +static int setup_ntlmssp_auth_req(char *ntlmsspblob,
> struct cifsSesInfo *ses,
> const struct nls_table *nls, bool first_time)
> {
> int bloblen;
>
> - bloblen = build_ntlmssp_auth_blob(&pSMB->req.SecurityBlob[0], ses, nls,
> + bloblen = build_ntlmssp_auth_blob(ntlmsspblob, ses, nls,
> first_time);
> - pSMB->req.SecurityBlobLength = cpu_to_le16(bloblen);
>
> return bloblen;
> }
> @@ -705,7 +713,7 @@ ssetup_ntlmssp_authenticate:
>
> if (first_time) /* should this be moved into common code
> with similar ntlmv2 path? */
> - cifs_calculate_mac_key(&ses->server->mac_signing_key,
> + cifs_calculate_session_key(&ses->server->session_key,
> ntlm_session_key, ses->password);
> /* copy session key */
>
> @@ -744,12 +752,23 @@ ssetup_ntlmssp_authenticate:
> cpu_to_le16(sizeof(struct ntlmv2_resp));
>
> /* calculate session key */
> - setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
> - /* FIXME: calculate MAC key */
> + rc = setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
> + if (rc) {
> + cERROR(1, "Error %d during NTLMv2 authentication", rc);
> + kfree(v2_sess_key);
> + goto ssetup_exit;
> + }
> memcpy(bcc_ptr, (char *)v2_sess_key,
> sizeof(struct ntlmv2_resp));
> bcc_ptr += sizeof(struct ntlmv2_resp);
> kfree(v2_sess_key);
> + if (ses->tilen > 0) {
> + memcpy(bcc_ptr, ses->tiblob,
> + ses->tilen);
> + bcc_ptr += ses->tilen;
> + kfree(ses->tiblob);
> + ses->tilen = 0;
> + }
> if (ses->capabilities & CAP_UNICODE) {
> if (iov[0].iov_len % 2) {
> *bcc_ptr = 0;
> @@ -780,15 +799,15 @@ ssetup_ntlmssp_authenticate:
> }
> /* bail out if key is too long */
> if (msg->sesskey_len >
> - sizeof(ses->server->mac_signing_key.data.krb5)) {
> + sizeof(ses->server->session_key.data.krb5)) {
> cERROR(1, "Kerberos signing key too long (%u bytes)",
> msg->sesskey_len);
> rc = -EOVERFLOW;
> goto ssetup_exit;
> }
> if (first_time) {
> - ses->server->mac_signing_key.len = msg->sesskey_len;
> - memcpy(ses->server->mac_signing_key.data.krb5,
> + ses->server->session_key.len = msg->sesskey_len;
> + memcpy(ses->server->session_key.data.krb5,
> msg->data, msg->sesskey_len);
> }
> pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
> @@ -830,12 +849,33 @@ ssetup_ntlmssp_authenticate:
> if (phase == NtLmNegotiate) {
> setup_ntlmssp_neg_req(pSMB, ses);
> iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
> + iov[1].iov_base = &pSMB->req.SecurityBlob[0];
> } else if (phase == NtLmAuthenticate) {
> int blob_len;
> - blob_len = setup_ntlmssp_auth_req(pSMB, ses,
> + char *ntlmsspblob;
> +
> + /* 5 is an empirical value, large enought to
> + * hold authenticate message, max 10 of
> + * av paris, doamin,user,workstation mames,
> + * flags etc..
> + */
> + ntlmsspblob = kmalloc(5 *
> + sizeof(struct _AUTHENTICATE_MESSAGE),
> + GFP_KERNEL);
> + if (!ntlmsspblob) {
> + cERROR(1, "Can't allocate NTLMSSP");
> + rc = -ENOMEM;
> + goto ssetup_exit;
> + }
> +
> + blob_len = setup_ntlmssp_auth_req(ntlmsspblob,
> + ses,
> nls_cp,
> first_time);
> iov[1].iov_len = blob_len;
> + iov[1].iov_base = ntlmsspblob;
> + pSMB->req.SecurityBlobLength =
> + cpu_to_le16(blob_len);
> /* Make sure that we tell the server that we
> are using the uid that it just gave us back
> on the response (challenge) */
> @@ -845,7 +885,6 @@ ssetup_ntlmssp_authenticate:
> rc = -ENOSYS;
> goto ssetup_exit;
> }
> - iov[1].iov_base = &pSMB->req.SecurityBlob[0];
> /* unicode strings must be word aligned */
> if ((iov[0].iov_len + iov[1].iov_len) % 2) {
> *bcc_ptr = 0;
> diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> index 82f78c4..a66c91e 100644
> --- a/fs/cifs/transport.c
> +++ b/fs/cifs/transport.c
> @@ -543,7 +543,7 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo
> *ses,
> (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
> SECMODE_SIGN_ENABLED))) {
> rc = cifs_verify_signature(midQ->resp_buf,
> - &ses->server->mac_signing_key,
> + &ses->server->session_key,
> midQ->sequence_number+1);
> if (rc) {
> cERROR(1, "Unexpected SMB signature");
> @@ -731,7 +731,7 @@ SendReceive(const unsigned int xid, struct cifsSesInfo
> *ses,
> (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
> SECMODE_SIGN_ENABLED))) {
> rc = cifs_verify_signature(out_buf,
> - &ses->server->mac_signing_key,
> + &ses->server->session_key,
> midQ->sequence_number+1);
> if (rc) {
> cERROR(1, "Unexpected SMB signature");
> @@ -981,7 +981,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct
> cifsTconInfo *tcon,
> (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
> SECMODE_SIGN_ENABLED))) {
> rc = cifs_verify_signature(out_buf,
> - &ses->server->mac_signing_key,
> + &ses->server->session_key,
> midQ->sequence_number+1);
> if (rc) {
> cERROR(1, "Unexpected SMB signature");
Would it be reasonable to split the simple mac_key to session_key
rename part into a separate patch from the ones that actually change
behavior?
--
Jeff Layton <[email protected]>
--
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