fs/cifs/cifsencrypt.c

   1 /*
   2  *   fs/cifs/cifsencrypt.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2005,2006
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Lesser General Public License as published
   9  *   by the Free Software Foundation; either version 2.1 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This library is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15  *   the GNU Lesser General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Lesser General Public License
  18  *   along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <linux/fs.h>
  23 #include "cifspdu.h"
  24 #include "cifsglob.h"
  25 #include "cifs_debug.h"
  26 #include "md5.h"
  27 #include "cifs_unicode.h"
  28 #include "cifsproto.h"
  29
  30 /* Calculate and return the CIFS signature based on the mac key and the smb pdu */
  31 /* the 16 byte signature must be allocated by the caller  */
  32 /* Note we only use the 1st eight bytes */
  33 /* Note that the smb header signature field on input contains the
  34         sequence number before this function is called */
  35
  36 extern void mdfour(unsigned char *out, unsigned char *in, int n);
  37 extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
  38
  39 static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu,
  40                                     const char * key, char * signature)
  41 {
  42         struct  MD5Context context;
  43
  44         if((cifs_pdu == NULL) || (signature == NULL))
  45                 return -EINVAL;
  46
  47         MD5Init(&context);
  48         MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
  49         MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
  50         MD5Final(signature,&context);
  51         return 0;
  52 }
  53
  54 int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server,
  55         __u32 * pexpected_response_sequence_number)
  56 {
  57         int rc = 0;
  58         char smb_signature[20];
  59
  60         /* BB remember to initialize sequence number elsewhere and initialize mac_signing key elsewhere BB */
  61         /* BB remember to add code to save expected sequence number in midQ entry BB */
  62
  63         if((cifs_pdu == NULL) || (server == NULL))
  64                 return -EINVAL;
  65
  66         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
  67                 return rc;
  68
  69         spin_lock(&GlobalMid_Lock);
  70         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number);
  71         cifs_pdu->Signature.Sequence.Reserved = 0;
  72
  73         *pexpected_response_sequence_number = server->sequence_number++;
  74         server->sequence_number++;
  75         spin_unlock(&GlobalMid_Lock);
  76
  77         rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature);
  78         if(rc)
  79                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
  80         else
  81                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
  82
  83         return rc;
  84 }
  85
  86 static int cifs_calc_signature2(const struct kvec * iov, int n_vec,
  87                                 const char * key, char * signature)
  88 {
  89         struct  MD5Context context;
  90
  91         if((iov == NULL) || (signature == NULL))
  92                 return -EINVAL;
  93
  94         MD5Init(&context);
  95         MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
  96
  97 /*        MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length); */ /* BB FIXME BB */
  98
  99         MD5Final(signature,&context);
 100
 101         return -EOPNOTSUPP;
 102 /*        return 0; */
 103 }
 104
 105
 106 int cifs_sign_smb2(struct kvec * iov, int n_vec, struct TCP_Server_Info *server,
 107                    __u32 * pexpected_response_sequence_number)
 108 {
 109         int rc = 0;
 110         char smb_signature[20];
 111         struct smb_hdr * cifs_pdu = iov[0].iov_base;
 112
 113         if((cifs_pdu == NULL) || (server == NULL))
 114                 return -EINVAL;
 115
 116         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
 117                 return rc;
 118
 119         spin_lock(&GlobalMid_Lock);
 120         cifs_pdu->Signature.Sequence.SequenceNumber =
 121                                 cpu_to_le32(server->sequence_number);
 122         cifs_pdu->Signature.Sequence.Reserved = 0;
 123
 124         *pexpected_response_sequence_number = server->sequence_number++;
 125         server->sequence_number++;
 126         spin_unlock(&GlobalMid_Lock);
 127
 128         rc = cifs_calc_signature2(iov, n_vec, server->mac_signing_key,
 129                                       smb_signature);
 130         if(rc)
 131                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 132         else
 133                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
 134
 135         return rc;
 136
 137 }
 138
 139 int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
 140         __u32 expected_sequence_number)
 141 {
 142         unsigned int rc;
 143         char server_response_sig[8];
 144         char what_we_think_sig_should_be[20];
 145
 146         if((cifs_pdu == NULL) || (mac_key == NULL))
 147                 return -EINVAL;
 148
 149         if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
 150                 return 0;
 151
 152         if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
 153                 struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
 154             if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
 155                         return 0;
 156         }
 157
 158         /* BB what if signatures are supposed to be on for session but server does not
 159                 send one? BB */
 160
 161         /* Do not need to verify session setups with signature "BSRSPYL "  */
 162         if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
 163                 cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));
 164
 165         /* save off the origiginal signature so we can modify the smb and check
 166                 its signature against what the server sent */
 167         memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);
 168
 169         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
 170         cifs_pdu->Signature.Sequence.Reserved = 0;
 171
 172         rc = cifs_calculate_signature(cifs_pdu, mac_key,
 173                 what_we_think_sig_should_be);
 174
 175         if(rc)
 176                 return rc;
 177
 178
 179 /*      cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */
 180
 181         if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
 182                 return -EACCES;
 183         else
 184                 return 0;
 185
 186 }
 187
 188 /* We fill in key by putting in 40 byte array which was allocated by caller */
 189 int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
 190 {
 191         char temp_key[16];
 192         if ((key == NULL) || (rn == NULL))
 193                 return -EINVAL;
 194
 195         E_md4hash(password, temp_key);
 196         mdfour(key,temp_key,16);
 197         memcpy(key+16,rn, CIFS_SESSION_KEY_SIZE);
 198         return 0;
 199 }
 200
 201 int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
 202 {
 203         char temp_hash[16];
 204         struct HMACMD5Context ctx;
 205         char * ucase_buf;
 206         __le16 * unicode_buf;
 207         unsigned int i,user_name_len,dom_name_len;
 208
 209         if(ses == NULL)
 210                 return -EINVAL;
 211
 212         E_md4hash(ses->password, temp_hash);
 213
 214         hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
 215         user_name_len = strlen(ses->userName);
 216         if(user_name_len > MAX_USERNAME_SIZE)
 217                 return -EINVAL;
 218         dom_name_len = strlen(ses->domainName);
 219         if(dom_name_len > MAX_USERNAME_SIZE)
 220                 return -EINVAL;
 221
 222         ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
 223         if(ucase_buf == NULL)
 224                 return -ENOMEM;
 225         unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
 226         if(unicode_buf == NULL) {
 227                 kfree(ucase_buf);
 228                 return -ENOMEM;
 229         }
 230
 231         for(i=0;i<user_name_len;i++)
 232                 ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
 233         ucase_buf[i] = 0;
 234         user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
 235         unicode_buf[user_name_len] = 0;
 236         user_name_len++;
 237
 238         for(i=0;i<dom_name_len;i++)
 239                 ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
 240         ucase_buf[i] = 0;
 241         dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
 242
 243         unicode_buf[user_name_len + dom_name_len] = 0;
 244         hmac_md5_update((const unsigned char *) unicode_buf,
 245                 (user_name_len+dom_name_len)*2,&ctx);
 246
 247         hmac_md5_final(ses->server->mac_signing_key,&ctx);
 248         kfree(ucase_buf);
 249         kfree(unicode_buf);
 250         return 0;
 251 }
 252 void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
 253 {
 254         struct HMACMD5Context context;
 255         memcpy(v2_session_response + 8, ses->server->cryptKey,8);
 256         /* gen_blob(v2_session_response + 16); */
 257         hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context);
 258
 259         hmac_md5_update(ses->server->cryptKey,8,&context);
 260 /*      hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */
 261
 262         hmac_md5_final(v2_session_response,&context);
 263         cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); /* BB removeme BB */
 264 }