/* * fs/cifs/cifsencrypt.c * * Copyright (C) International Business Machines Corp., 2005,2006 * Author(s): Steve French (sfrench@us.ibm.com) * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/fs.h> #include "cifspdu.h" #include "cifsglob.h" #include "cifs_debug.h" #include "md5.h" #include "cifs_unicode.h" #include "cifsproto.h" #include <linux/ctype.h> #include <linux/random.h> /* Calculate and return the CIFS signature based on the mac key and the smb pdu */ /* the 16 byte signature must be allocated by the caller */ /* Note we only use the 1st eight bytes */ /* Note that the smb header signature field on input contains the sequence number before this function is called */ extern void mdfour(unsigned char *out, unsigned char *in, int n); extern void E_md4hash(const unsigned char *passwd, unsigned char *p16); extern void SMBencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24); static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu, const char * key, char * signature) { struct MD5Context context; if((cifs_pdu == NULL) || (signature == NULL)) return -EINVAL; MD5Init(&context); MD5Update(&context,key,CIFS_SESS_KEY_SIZE+16); MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length); MD5Final(signature,&context); return 0; } int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server, __u32 * pexpected_response_sequence_number) { int rc = 0; char smb_signature[20]; if((cifs_pdu == NULL) || (server == NULL)) return -EINVAL; if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) return rc; spin_lock(&GlobalMid_Lock); 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++; spin_unlock(&GlobalMid_Lock); rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature); if(rc) memset(cifs_pdu->Signature.SecuritySignature, 0, 8); else memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8); return rc; } static int cifs_calc_signature2(const struct kvec * iov, int n_vec, const char * key, char * signature) { struct MD5Context context; int i; if((iov == NULL) || (signature == NULL)) return -EINVAL; MD5Init(&context); MD5Update(&context,key,CIFS_SESS_KEY_SIZE+16); for(i=0;i<n_vec;i++) { if(iov[i].iov_base == NULL) { cERROR(1,("null iovec entry")); return -EIO; } else if(iov[i].iov_len == 0) break; /* bail out if we are sent nothing to sign */ /* The first entry includes a length field (which does not get signed that occupies the first 4 bytes before the header */ if(i==0) { if (iov[0].iov_len <= 8 ) /* cmd field at offset 9 */ break; /* nothing to sign or corrupt header */ MD5Update(&context,iov[0].iov_base+4, iov[0].iov_len-4); } else MD5Update(&context,iov[i].iov_base, iov[i].iov_len); } MD5Final(signature,&context); return 0; } int cifs_sign_smb2(struct kvec * iov, int n_vec, struct TCP_Server_Info *server, __u32 * pexpected_response_sequence_number) { int rc = 0; char smb_signature[20]; struct smb_hdr * cifs_pdu = iov[0].iov_base; if((cifs_pdu == NULL) || (server == NULL)) return -EINVAL; if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0) return rc; spin_lock(&GlobalMid_Lock); 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++; spin_unlock(&GlobalMid_Lock); rc = cifs_calc_signature2(iov, n_vec, server->mac_signing_key, 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 smb_hdr * cifs_pdu, const char * mac_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)) return -EINVAL; if (cifs_pdu->Command == SMB_COM_NEGOTIATE) 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; rc = cifs_calculate_signature(cifs_pdu, mac_key, what_we_think_sig_should_be); 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; } /* We fill in key by putting in 40 byte array which was allocated by caller */ int cifs_calculate_mac_key(char * key, const char * rn, const char * password) { char temp_key[16]; if ((key == NULL) || (rn == NULL)) return -EINVAL; E_md4hash(password, temp_key); mdfour(key,temp_key,16); memcpy(key+16,rn, CIFS_SESS_KEY_SIZE); return 0; } int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, const struct nls_table * nls_info) { char temp_hash[16]; struct HMACMD5Context ctx; char * ucase_buf; __le16 * unicode_buf; unsigned int i,user_name_len,dom_name_len; if(ses == NULL) return -EINVAL; E_md4hash(ses->password, temp_hash); hmac_md5_init_limK_to_64(temp_hash, 16, &ctx); user_name_len = strlen(ses->userName); if(user_name_len > MAX_USERNAME_SIZE) return -EINVAL; if(ses->domainName == NULL) return -EINVAL; /* BB should we use CIFS_LINUX_DOM */ dom_name_len = strlen(ses->domainName); if(dom_name_len > MAX_USERNAME_SIZE) return -EINVAL; ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL); if(ucase_buf == NULL) return -ENOMEM; unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL); if(unicode_buf == NULL) { kfree(ucase_buf); return -ENOMEM; } for(i=0;i<user_name_len;i++) ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]]; ucase_buf[i] = 0; user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info); unicode_buf[user_name_len] = 0; user_name_len++; for(i=0;i<dom_name_len;i++) ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]]; ucase_buf[i] = 0; dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info); unicode_buf[user_name_len + dom_name_len] = 0; hmac_md5_update((const unsigned char *) unicode_buf, (user_name_len+dom_name_len)*2,&ctx); hmac_md5_final(ses->server->mac_signing_key,&ctx); kfree(ucase_buf); kfree(unicode_buf); return 0; } #ifdef CONFIG_CIFS_WEAK_PW_HASH void calc_lanman_hash(struct cifsSesInfo * ses, char * lnm_session_key) { int i; char password_with_pad[CIFS_ENCPWD_SIZE]; if(ses->server == NULL) return; memset(password_with_pad, 0, CIFS_ENCPWD_SIZE); if(ses->password) strncpy(password_with_pad, ses->password, CIFS_ENCPWD_SIZE); if((ses->server->secMode & SECMODE_PW_ENCRYPT) == 0) if(extended_security & CIFSSEC_MAY_PLNTXT) { memcpy(lnm_session_key, password_with_pad, CIFS_ENCPWD_SIZE); return; } /* calculate old style session key */ /* calling toupper is less broken than repeatedly calling nls_toupper would be since that will never work for UTF8, but neither handles multibyte code pages but the only alternative would be converting to UCS-16 (Unicode) (using a routine something like UniStrupr) then uppercasing and then converting back from Unicode - which would only worth doing it if we knew it were utf8. Basically utf8 and other multibyte codepages each need their own strupper function since a byte at a time will ont work. */ for(i = 0; i < CIFS_ENCPWD_SIZE; i++) { password_with_pad[i] = toupper(password_with_pad[i]); } SMBencrypt(password_with_pad, ses->server->cryptKey, lnm_session_key); /* clear password before we return/free memory */ memset(password_with_pad, 0, CIFS_ENCPWD_SIZE); } #endif /* CIFS_WEAK_PW_HASH */ static int calc_ntlmv2_hash(struct cifsSesInfo *ses, const struct nls_table * nls_cp) { int rc = 0; int len; char nt_hash[16]; struct HMACMD5Context * pctxt; wchar_t * user; wchar_t * domain; pctxt = kmalloc(sizeof(struct HMACMD5Context), GFP_KERNEL); if(pctxt == NULL) return -ENOMEM; /* calculate md4 hash of password */ E_md4hash(ses->password, nt_hash); /* convert Domainname to unicode and uppercase */ hmac_md5_init_limK_to_64(nt_hash, 16, pctxt); /* convert ses->userName to unicode and uppercase */ len = strlen(ses->userName); user = kmalloc(2 + (len * 2), GFP_KERNEL); if(user == NULL) goto calc_exit_2; len = cifs_strtoUCS(user, ses->userName, len, nls_cp); UniStrupr(user); hmac_md5_update((char *)user, 2*len, pctxt); /* convert ses->domainName to unicode and uppercase */ if(ses->domainName) { len = strlen(ses->domainName); domain = kmalloc(2 + (len * 2), GFP_KERNEL); if(domain == NULL) goto calc_exit_1; len = cifs_strtoUCS(domain, ses->domainName, len, nls_cp); UniStrupr(domain); hmac_md5_update((char *)domain, 2*len, pctxt); kfree(domain); } calc_exit_1: kfree(user); calc_exit_2: /* BB FIXME what about bytes 24 through 40 of the signing key? compare with the NTLM example */ hmac_md5_final(ses->server->mac_signing_key, pctxt); return rc; } void setup_ntlmv2_rsp(struct cifsSesInfo * ses, char * resp_buf, const struct nls_table * nls_cp) { int rc; struct ntlmv2_resp * buf = (struct ntlmv2_resp *)resp_buf; buf->blob_signature = cpu_to_le32(0x00000101); buf->reserved = 0; buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME)); get_random_bytes(&buf->client_chal, sizeof(buf->client_chal)); buf->reserved2 = 0; buf->names[0].type = 0; buf->names[0].length = 0; /* calculate buf->ntlmv2_hash */ rc = calc_ntlmv2_hash(ses, nls_cp); if(rc) cERROR(1,("could not get v2 hash rc %d",rc)); CalcNTLMv2_response(ses, resp_buf); } void CalcNTLMv2_response(const struct cifsSesInfo * ses, char * v2_session_response) { struct HMACMD5Context context; /* rest of v2 struct already generated */ memcpy(v2_session_response + 8, ses->server->cryptKey,8); hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context); hmac_md5_update(v2_session_response+8, sizeof(struct ntlmv2_resp) - 8, &context); hmac_md5_final(v2_session_response,&context); /* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */ }