cifs: dynamic allocation of ntlmssp blob
[pandora-kernel.git] / fs / cifs / sess.c
index 4ec3ee9..91b51e4 100644 (file)
@@ -198,7 +198,7 @@ static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
                bytes_ret = 0;
        } else
                bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->domainName,
-                                         256, nls_cp);
+                                         CIFS_MAX_DOMAINNAME_LEN, nls_cp);
        bcc_ptr += 2 * bytes_ret;
        bcc_ptr += 2;  /* account for null terminator */
 
@@ -246,19 +246,18 @@ static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
        /* copy user */
        /* BB what about null user mounts - check that we do this BB */
        /* copy user */
-       if (ses->user_name != NULL)
+       if (ses->user_name != NULL) {
                strncpy(bcc_ptr, ses->user_name, MAX_USERNAME_SIZE);
+               bcc_ptr += strnlen(ses->user_name, MAX_USERNAME_SIZE);
+       }
        /* else null user mount */
-
-       bcc_ptr += strnlen(ses->user_name, MAX_USERNAME_SIZE);
        *bcc_ptr = 0;
        bcc_ptr++; /* account for null termination */
 
        /* copy domain */
-
        if (ses->domainName != NULL) {
-               strncpy(bcc_ptr, ses->domainName, 256);
-               bcc_ptr += strnlen(ses->domainName, 256);
+               strncpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
+               bcc_ptr += strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
        } /* else we will send a null domain name
             so the server will default to its own domain */
        *bcc_ptr = 0;
@@ -445,19 +444,43 @@ static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
        sec_blob->DomainName.MaximumLength = 0;
 }
 
-/* We do not malloc the blob, it is passed in pbuffer, because its
-   maximum possible size is fixed and small, making this approach cleaner.
-   This function returns the length of the data in the blob */
-static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
+static int size_of_ntlmssp_blob(struct cifs_ses *ses)
+{
+       int sz = sizeof(AUTHENTICATE_MESSAGE) + ses->auth_key.len
+               - CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
+
+       if (ses->domainName)
+               sz += 2 * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
+       else
+               sz += 2;
+
+       if (ses->user_name)
+               sz += 2 * strnlen(ses->user_name, MAX_USERNAME_SIZE);
+       else
+               sz += 2;
+
+       return sz;
+}
+
+static int build_ntlmssp_auth_blob(unsigned char **pbuffer,
                                        u16 *buflen,
                                   struct cifs_ses *ses,
                                   const struct nls_table *nls_cp)
 {
        int rc;
-       AUTHENTICATE_MESSAGE *sec_blob = (AUTHENTICATE_MESSAGE *)pbuffer;
+       AUTHENTICATE_MESSAGE *sec_blob;
        __u32 flags;
        unsigned char *tmp;
 
+       rc = setup_ntlmv2_rsp(ses, nls_cp);
+       if (rc) {
+               cERROR(1, "Error %d during NTLMSSP authentication", rc);
+               *buflen = 0;
+               goto setup_ntlmv2_ret;
+       }
+       *pbuffer = kmalloc(size_of_ntlmssp_blob(ses), GFP_KERNEL);
+       sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
+
        memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
        sec_blob->MessageType = NtLmAuthenticate;
 
@@ -472,7 +495,7 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
                        flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
        }
 
-       tmp = pbuffer + sizeof(AUTHENTICATE_MESSAGE);
+       tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
        sec_blob->NegotiateFlags = cpu_to_le32(flags);
 
        sec_blob->LmChallengeResponse.BufferOffset =
@@ -480,23 +503,27 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
        sec_blob->LmChallengeResponse.Length = 0;
        sec_blob->LmChallengeResponse.MaximumLength = 0;
 
-       sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
-       rc = setup_ntlmv2_rsp(ses, nls_cp);
-       if (rc) {
-               cERROR(1, "Error %d during NTLMSSP authentication", rc);
-               goto setup_ntlmv2_ret;
-       }
-       memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
-                       ses->auth_key.len - CIFS_SESS_KEY_SIZE);
-       tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
+       sec_blob->NtChallengeResponse.BufferOffset =
+                               cpu_to_le32(tmp - *pbuffer);
+       if (ses->user_name != NULL) {
+               memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+                               ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+               tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
 
-       sec_blob->NtChallengeResponse.Length =
-                       cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
-       sec_blob->NtChallengeResponse.MaximumLength =
-                       cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+               sec_blob->NtChallengeResponse.Length =
+                               cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+               sec_blob->NtChallengeResponse.MaximumLength =
+                               cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+       } else {
+               /*
+                * don't send an NT Response for anonymous access
+                */
+               sec_blob->NtChallengeResponse.Length = 0;
+               sec_blob->NtChallengeResponse.MaximumLength = 0;
+       }
 
        if (ses->domainName == NULL) {
-               sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
+               sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - *pbuffer);
                sec_blob->DomainName.Length = 0;
                sec_blob->DomainName.MaximumLength = 0;
                tmp += 2;
@@ -505,14 +532,14 @@ 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 */
-               sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
+               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);
                tmp += len;
        }
 
        if (ses->user_name == NULL) {
-               sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
+               sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - *pbuffer);
                sec_blob->UserName.Length = 0;
                sec_blob->UserName.MaximumLength = 0;
                tmp += 2;
@@ -521,13 +548,13 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
                len = cifs_strtoUCS((__le16 *)tmp, ses->user_name,
                                    MAX_USERNAME_SIZE, nls_cp);
                len *= 2; /* unicode is 2 bytes each */
-               sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
+               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);
                tmp += len;
        }
 
-       sec_blob->WorkstationName.BufferOffset = cpu_to_le32(tmp - pbuffer);
+       sec_blob->WorkstationName.BufferOffset = cpu_to_le32(tmp - *pbuffer);
        sec_blob->WorkstationName.Length = 0;
        sec_blob->WorkstationName.MaximumLength = 0;
        tmp += 2;
@@ -536,19 +563,19 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
                (ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC))
                        && !calc_seckey(ses)) {
                memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
-               sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+               sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
                sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
                sec_blob->SessionKey.MaximumLength =
                                cpu_to_le16(CIFS_CPHTXT_SIZE);
                tmp += CIFS_CPHTXT_SIZE;
        } else {
-               sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+               sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
                sec_blob->SessionKey.Length = 0;
                sec_blob->SessionKey.MaximumLength = 0;
        }
 
+       *buflen = tmp - *pbuffer;
 setup_ntlmv2_ret:
-       *buflen = tmp - pbuffer;
        return rc;
 }
 
@@ -571,7 +598,7 @@ CIFS_SessSetup(unsigned int xid, struct cifs_ses *ses,
        struct key *spnego_key = NULL;
        __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
        u16 blob_len;
-       char *ntlmsspblob = NULL;
+       unsigned char *ntlmsspblob = NULL;
 
        if (ses == NULL)
                return -EINVAL;
@@ -648,23 +675,25 @@ ssetup_ntlmssp_authenticate:
 
                pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;
 
-               /* no capabilities flags in old lanman negotiation */
-
-               pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);
-
-               /* Calculate hash with password and copy into bcc_ptr.
-                * Encryption Key (stored as in cryptkey) gets used if the
-                * security mode bit in Negottiate Protocol response states
-                * to use challenge/response method (i.e. Password bit is 1).
-                */
-
-               rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
-                                ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
-                                       true : false, lnm_session_key);
+               if (ses->user_name != NULL) {
+                       /* no capabilities flags in old lanman negotiation */
+                       pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);
 
+                       /* Calculate hash with password and copy into bcc_ptr.
+                        * Encryption Key (stored as in cryptkey) gets used if the
+                        * security mode bit in Negottiate Protocol response states
+                        * to use challenge/response method (i.e. Password bit is 1).
+                        */
+                       rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
+                                             ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
+                                             true : false, lnm_session_key);
+
+                       memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
+                       bcc_ptr += CIFS_AUTH_RESP_SIZE;
+               } else {
+                       pSMB->old_req.PasswordLength = 0;
+               }
                ses->flags |= CIFS_SES_LANMAN;
-               memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
-               bcc_ptr += CIFS_AUTH_RESP_SIZE;
 
                /* can not sign if LANMAN negotiated so no need
                to calculate signing key? but what if server
@@ -677,25 +706,31 @@ ssetup_ntlmssp_authenticate:
 #endif
        } else if (type == NTLM) {
                pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
-               pSMB->req_no_secext.CaseInsensitivePasswordLength =
-                       cpu_to_le16(CIFS_AUTH_RESP_SIZE);
-               pSMB->req_no_secext.CaseSensitivePasswordLength =
-                       cpu_to_le16(CIFS_AUTH_RESP_SIZE);
-
-               /* calculate ntlm response and session key */
-               rc = setup_ntlm_response(ses, nls_cp);
-               if (rc) {
-                       cERROR(1, "Error %d during NTLM authentication", rc);
-                       goto ssetup_exit;
-               }
+               if (ses->user_name != NULL) {
+                       pSMB->req_no_secext.CaseInsensitivePasswordLength =
+                                       cpu_to_le16(CIFS_AUTH_RESP_SIZE);
+                       pSMB->req_no_secext.CaseSensitivePasswordLength =
+                                       cpu_to_le16(CIFS_AUTH_RESP_SIZE);
+
+                       /* calculate ntlm response and session key */
+                       rc = setup_ntlm_response(ses, nls_cp);
+                       if (rc) {
+                               cERROR(1, "Error %d during NTLM authentication",
+                                                rc);
+                               goto ssetup_exit;
+                       }
 
-               /* copy ntlm response */
-               memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
-                               CIFS_AUTH_RESP_SIZE);
-               bcc_ptr += CIFS_AUTH_RESP_SIZE;
-               memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
-                               CIFS_AUTH_RESP_SIZE);
-               bcc_ptr += CIFS_AUTH_RESP_SIZE;
+                       /* copy ntlm response */
+                       memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+                                       CIFS_AUTH_RESP_SIZE);
+                       bcc_ptr += CIFS_AUTH_RESP_SIZE;
+                       memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+                                       CIFS_AUTH_RESP_SIZE);
+                       bcc_ptr += CIFS_AUTH_RESP_SIZE;
+               } else {
+                       pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
+                       pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
+               }
 
                if (ses->capabilities & CAP_UNICODE) {
                        /* unicode strings must be word aligned */
@@ -712,21 +747,26 @@ ssetup_ntlmssp_authenticate:
                /* LM2 password would be here if we supported it */
                pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
 
-               /* calculate nlmv2 response and session key */
-               rc = setup_ntlmv2_rsp(ses, nls_cp);
-               if (rc) {
-                       cERROR(1, "Error %d during NTLMv2 authentication", rc);
-                       goto ssetup_exit;
-               }
-               memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
-                               ses->auth_key.len - CIFS_SESS_KEY_SIZE);
-               bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
+               if (ses->user_name != NULL) {
+                       /* calculate nlmv2 response and session key */
+                       rc = setup_ntlmv2_rsp(ses, nls_cp);
+                       if (rc) {
+                               cERROR(1, "Error %d during NTLMv2 authentication", rc);
+                               goto ssetup_exit;
+                       }
 
-               /* set case sensitive password length after tilen may get
-                * assigned, tilen is 0 otherwise.
-                */
-               pSMB->req_no_secext.CaseSensitivePasswordLength =
-                       cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+                       memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+                                       ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+                       bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
+
+                       /* set case sensitive password length after tilen may get
+                        * assigned, tilen is 0 otherwise.
+                        */
+                       pSMB->req_no_secext.CaseSensitivePasswordLength =
+                               cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+               } else {
+                       pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
+               }
 
                if (ses->capabilities & CAP_UNICODE) {
                        if (iov[0].iov_len % 2) {
@@ -812,21 +852,7 @@ ssetup_ntlmssp_authenticate:
                                cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));
                        break;
                case NtLmAuthenticate:
-                       /*
-                        * 5 is an empirical value, large enough to hold
-                        * authenticate message plus max 10 of av paris,
-                        * domain, user, workstation names, flags, etc.
-                        */
-                       ntlmsspblob = kzalloc(
-                               5*sizeof(struct _AUTHENTICATE_MESSAGE),
-                               GFP_KERNEL);
-                       if (!ntlmsspblob) {
-                               cERROR(1, "Can't allocate NTLMSSP blob");
-                               rc = -ENOMEM;
-                               goto ssetup_exit;
-                       }
-
-                       rc = build_ntlmssp_auth_blob(ntlmsspblob,
+                       rc = build_ntlmssp_auth_blob(&ntlmsspblob,
                                                &blob_len, ses, nls_cp);
                        if (rc)
                                goto ssetup_exit;