/* must be called with server->srv_mutex held */ int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server, __u32 *pexpected_response_sequence_number) { int rc = 0; char smb_signature[20]; struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base; if ((cifs_pdu == NULL) || (server == NULL)) return -EINVAL; if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) || server->tcpStatus == CifsNeedNegotiate) return rc; if (!server->session_estab) { memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8); return rc; } cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number); cifs_pdu->Signature.Sequence.Reserved = 0; *pexpected_response_sequence_number = ++server->sequence_number; ++server->sequence_number; rc = cifs_calc_signature(rqst, server, smb_signature); if (rc) memset(cifs_pdu->Signature.SecuritySignature, 0, 8); else memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8); return rc; }
int cifs_verify_signature(struct kvec *iov, unsigned int nr_iov, struct TCP_Server_Info *server, __u32 expected_sequence_number) { unsigned int rc; char server_response_sig[8]; char what_we_think_sig_should_be[20]; struct smb_hdr *cifs_pdu = (struct smb_hdr *)iov[0].iov_base; if (cifs_pdu == NULL || server == NULL) return -EINVAL; if (!server->session_estab) return 0; if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) { struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)cifs_pdu; if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE) return 0; } /* BB what if signatures are supposed to be on for session but server does not send one? BB */ /* Do not need to verify session setups with signature "BSRSPYL " */ if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0) cFYI(1, "dummy signature received for smb command 0x%x", cifs_pdu->Command); /* save off the origiginal signature so we can modify the smb and check its signature against what the server sent */ memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8); cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number); cifs_pdu->Signature.Sequence.Reserved = 0; mutex_lock(&server->srv_mutex); rc = cifs_calc_signature(iov, nr_iov, server, what_we_think_sig_should_be); mutex_unlock(&server->srv_mutex); if (rc) return rc; /* cifs_dump_mem("what we think it should be: ", what_we_think_sig_should_be, 16); */ if (memcmp(server_response_sig, what_we_think_sig_should_be, 8)) return -EACCES; else return 0; }