From ee03c646dd70dafb28a894119f6e8f0033c974dc Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Mon, 16 Jun 2014 15:35:27 +0100 Subject: [PATCH] cifs: Split Kerberos authentication off CIFS_SessSetup() Signed-off-by: Sachin Prabhu Reviewed-by: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/sess.c | 215 +++++++++++++++++++++++++++++++++++-------------- 1 file changed, 153 insertions(+), 62 deletions(-) diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index 4f481c133f6e..b413fae993aa 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -963,6 +963,155 @@ out: ses->auth_key.response = NULL; } +#ifdef CONFIG_CIFS_UPCALL +static void +sess_auth_kerberos(struct sess_data *sess_data) +{ + int rc = 0; + struct smb_hdr *smb_buf; + SESSION_SETUP_ANDX *pSMB; + char *bcc_ptr; + struct cifs_ses *ses = sess_data->ses; + __u32 capabilities; + __u16 bytes_remaining; + struct key *spnego_key = NULL; + struct cifs_spnego_msg *msg; + u16 blob_len; + + /* extended security */ + /* wct = 12 */ + rc = sess_alloc_buffer(sess_data, 12); + if (rc) + goto out; + + pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base; + bcc_ptr = sess_data->iov[2].iov_base; + capabilities = cifs_ssetup_hdr(ses, pSMB); + + spnego_key = cifs_get_spnego_key(ses); + if (IS_ERR(spnego_key)) { + rc = PTR_ERR(spnego_key); + spnego_key = NULL; + goto out; + } + + msg = spnego_key->payload.data; + /* + * check version field to make sure that cifs.upcall is + * sending us a response in an expected form + */ + if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) { + cifs_dbg(VFS, + "incorrect version of cifs.upcall (expected %d but got %d)", + CIFS_SPNEGO_UPCALL_VERSION, msg->version); + rc = -EKEYREJECTED; + goto out_put_spnego_key; + } + + ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len, + GFP_KERNEL); + if (!ses->auth_key.response) { + cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory", + msg->sesskey_len); + rc = -ENOMEM; + goto out_put_spnego_key; + } + ses->auth_key.len = msg->sesskey_len; + + pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC; + capabilities |= CAP_EXTENDED_SECURITY; + pSMB->req.Capabilities = cpu_to_le32(capabilities); + sess_data->iov[1].iov_base = msg->data + msg->sesskey_len; + sess_data->iov[1].iov_len = msg->secblob_len; + pSMB->req.SecurityBlobLength = cpu_to_le16(sess_data->iov[1].iov_len); + + if (ses->capabilities & CAP_UNICODE) { + /* unicode strings must be word aligned */ + if ((sess_data->iov[0].iov_len + + sess_data->iov[1].iov_len) % 2) { + *bcc_ptr = 0; + bcc_ptr++; + } + unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp); + unicode_domain_string(&bcc_ptr, ses, sess_data->nls_cp); + } else { + /* BB: is this right? */ + ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp); + } + + sess_data->iov[2].iov_len = (long) bcc_ptr - + (long) sess_data->iov[2].iov_base; + + rc = sess_sendreceive(sess_data); + if (rc) + goto out_put_spnego_key; + + pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base; + smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base; + + if (smb_buf->WordCount != 4) { + rc = -EIO; + cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount); + goto out_put_spnego_key; + } + + if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN) + cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */ + + ses->Suid = smb_buf->Uid; /* UID left in wire format (le) */ + cifs_dbg(FYI, "UID = %llu\n", ses->Suid); + + bytes_remaining = get_bcc(smb_buf); + bcc_ptr = pByteArea(smb_buf); + + blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength); + if (blob_len > bytes_remaining) { + cifs_dbg(VFS, "bad security blob length %d\n", + blob_len); + rc = -EINVAL; + goto out_put_spnego_key; + } + bcc_ptr += blob_len; + bytes_remaining -= blob_len; + + /* BB check if Unicode and decode strings */ + if (bytes_remaining == 0) { + /* no string area to decode, do nothing */ + } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) { + /* unicode string area must be word-aligned */ + if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) { + ++bcc_ptr; + --bytes_remaining; + } + decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses, + sess_data->nls_cp); + } else { + decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses, + sess_data->nls_cp); + } + + rc = sess_establish_session(sess_data); +out_put_spnego_key: + key_invalidate(spnego_key); + key_put(spnego_key); +out: + sess_data->result = rc; + sess_data->func = NULL; + sess_free_buffer(sess_data); + kfree(ses->auth_key.response); + ses->auth_key.response = NULL; +} + +#else + +static void +sess_auth_kerberos(struct sess_data *sess_data) +{ + cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n"); + sess_data->result = -ENOSYS; + sess_data->func = NULL; +} +#endif /* ! CONFIG_CIFS_UPCALL */ int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses, @@ -980,7 +1129,6 @@ CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses, struct kvec iov[3]; enum securityEnum type; __u16 action, bytes_remaining; - struct key *spnego_key = NULL; __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */ u16 blob_len; char *ntlmsspblob = NULL; @@ -1017,6 +1165,9 @@ CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses, case NTLMv2: sess_auth_ntlmv2(sess_data); goto out; + case Kerberos: + sess_auth_kerberos(sess_data); + goto out; default: cifs_dbg(FYI, "Continuing with CIFS_SessSetup\n"); } @@ -1072,63 +1223,7 @@ ssetup_ntlmssp_authenticate: iov[1].iov_base = NULL; iov[1].iov_len = 0; - if (type == Kerberos) { -#ifdef CONFIG_CIFS_UPCALL - struct cifs_spnego_msg *msg; - - spnego_key = cifs_get_spnego_key(ses); - if (IS_ERR(spnego_key)) { - rc = PTR_ERR(spnego_key); - spnego_key = NULL; - goto ssetup_exit; - } - - msg = spnego_key->payload.data; - /* check version field to make sure that cifs.upcall is - sending us a response in an expected form */ - if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) { - cifs_dbg(VFS, "incorrect version of cifs.upcall " - "expected %d but got %d)", - CIFS_SPNEGO_UPCALL_VERSION, msg->version); - rc = -EKEYREJECTED; - goto ssetup_exit; - } - - ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len, - GFP_KERNEL); - if (!ses->auth_key.response) { - cifs_dbg(VFS, - "Kerberos can't allocate (%u bytes) memory", - msg->sesskey_len); - rc = -ENOMEM; - goto ssetup_exit; - } - ses->auth_key.len = msg->sesskey_len; - - pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC; - capabilities |= CAP_EXTENDED_SECURITY; - pSMB->req.Capabilities = cpu_to_le32(capabilities); - iov[1].iov_base = msg->data + msg->sesskey_len; - iov[1].iov_len = msg->secblob_len; - pSMB->req.SecurityBlobLength = cpu_to_le16(iov[1].iov_len); - - if (ses->capabilities & CAP_UNICODE) { - /* unicode strings must be word aligned */ - if ((iov[0].iov_len + iov[1].iov_len) % 2) { - *bcc_ptr = 0; - bcc_ptr++; - } - unicode_oslm_strings(&bcc_ptr, nls_cp); - unicode_domain_string(&bcc_ptr, ses, nls_cp); - } else - /* BB: is this right? */ - ascii_ssetup_strings(&bcc_ptr, ses, nls_cp); -#else /* ! CONFIG_CIFS_UPCALL */ - cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n"); - rc = -ENOSYS; - goto ssetup_exit; -#endif /* CONFIG_CIFS_UPCALL */ - } else if (type == RawNTLMSSP) { + if (type == RawNTLMSSP) { if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) { cifs_dbg(VFS, "NTLMSSP requires Unicode support\n"); rc = -ENOSYS; @@ -1268,10 +1363,6 @@ ssetup_ntlmssp_authenticate: } ssetup_exit: - if (spnego_key) { - key_invalidate(spnego_key); - key_put(spnego_key); - } kfree(str_area); kfree(ntlmsspblob); ntlmsspblob = NULL; -- 2.20.1