fs/cifs/cifsencrypt.c

   1 /*
   2  *   fs/cifs/cifsencrypt.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2005
   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, const char * key, char * signature)
  40 {
  41         struct  MD5Context context;
  42
  43         if((cifs_pdu == NULL) || (signature == NULL))
  44                 return -EINVAL;
  45
  46         MD5Init(&context);
  47         MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
  48         MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
  49         MD5Final(signature,&context);
  50         return 0;
  51 }
  52
  53 int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server,
  54         __u32 * pexpected_response_sequence_number)
  55 {
  56         int rc = 0;
  57         char smb_signature[20];
  58
  59         /* BB remember to initialize sequence number elsewhere and initialize mac_signing key elsewhere BB */
  60         /* BB remember to add code to save expected sequence number in midQ entry BB */
  61
  62         if((cifs_pdu == NULL) || (server == NULL))
  63                 return -EINVAL;
  64
  65         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
  66                 return rc;
  67
  68         spin_lock(&GlobalMid_Lock);
  69         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number);
  70         cifs_pdu->Signature.Sequence.Reserved = 0;
  71
  72         *pexpected_response_sequence_number = server->sequence_number++;
  73         server->sequence_number++;
  74         spin_unlock(&GlobalMid_Lock);
  75
  76         rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature);
  77         if(rc)
  78                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
  79         else
  80                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
  81
  82         return rc;
  83 }
  84
  85 static int cifs_calc_signature2(const struct kvec * iov, int n_vec,
  86                                 const char * key, char * signature)
  87 {
  88         struct  MD5Context context;
  89
  90         if((iov == NULL) || (signature == NULL))
  91                 return -EINVAL;
  92
  93         MD5Init(&context);
  94         MD5Update(&context,key,CIFS_SESSION_KEY_SIZE+16);
  95
  96 /*        MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length); */ /* BB FIXME BB */
  97
  98         MD5Final(signature,&context);
  99
 100         return -EOPNOTSUPP;
 101 /*        return 0; */
 102 }
 103
 104
 105 int cifs_sign_smb2(struct kvec * iov, int n_vec, struct TCP_Server_Info *server,
 106                    __u32 * pexpected_response_sequence_number)
 107 {
 108         int rc = 0;
 109         char smb_signature[20];
 110         struct smb_hdr * cifs_pdu = iov[0].iov_base;
 111
 112         if((cifs_pdu == NULL) || (server == NULL))
 113                 return -EINVAL;
 114
 115         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
 116                 return rc;
 117
 118         spin_lock(&GlobalMid_Lock);
 119         cifs_pdu->Signature.Sequence.SequenceNumber =
 120                                 cpu_to_le32(server->sequence_number);
 121         cifs_pdu->Signature.Sequence.Reserved = 0;
 122
 123         *pexpected_response_sequence_number = server->sequence_number++;
 124         server->sequence_number++;
 125         spin_unlock(&GlobalMid_Lock);
 126
 127         rc = cifs_calc_signature2(iov, n_vec, server->mac_signing_key,
 128                                       smb_signature);
 129         if(rc)
 130                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 131         else
 132                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
 133
 134         return rc;
 135
 136 }
 137
 138 int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
 139         __u32 expected_sequence_number)
 140 {
 141         unsigned int rc;
 142         char server_response_sig[8];
 143         char what_we_think_sig_should_be[20];
 144
 145         if((cifs_pdu == NULL) || (mac_key == NULL))
 146                 return -EINVAL;
 147
 148         if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
 149                 return 0;
 150
 151         if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
 152                 struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
 153             if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
 154                         return 0;
 155         }
 156
 157         /* BB what if signatures are supposed to be on for session but server does not
 158                 send one? BB */
 159
 160         /* Do not need to verify session setups with signature "BSRSPYL "  */
 161         if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
 162                 cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));
 163
 164         /* save off the origiginal signature so we can modify the smb and check
 165                 its signature against what the server sent */
 166         memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);
 167
 168         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
 169         cifs_pdu->Signature.Sequence.Reserved = 0;
 170
 171         rc = cifs_calculate_signature(cifs_pdu, mac_key,
 172                 what_we_think_sig_should_be);
 173
 174         if(rc)
 175                 return rc;
 176
 177
 178 /*      cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */
 179
 180         if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
 181                 return -EACCES;
 182         else
 183                 return 0;
 184
 185 }
 186
 187 /* We fill in key by putting in 40 byte array which was allocated by caller */
 188 int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
 189 {
 190         char temp_key[16];
 191         if ((key == NULL) || (rn == NULL))
 192                 return -EINVAL;
 193
 194         E_md4hash(password, temp_key);
 195         mdfour(key,temp_key,16);
 196         memcpy(key+16,rn, CIFS_SESSION_KEY_SIZE);
 197         return 0;
 198 }
 199
 200 int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
 201 {
 202         char temp_hash[16];
 203         struct HMACMD5Context ctx;
 204         char * ucase_buf;
 205         __le16 * unicode_buf;
 206         unsigned int i,user_name_len,dom_name_len;
 207
 208         if(ses == NULL)
 209                 return -EINVAL;
 210
 211         E_md4hash(ses->password, temp_hash);
 212
 213         hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
 214         user_name_len = strlen(ses->userName);
 215         if(user_name_len > MAX_USERNAME_SIZE)
 216                 return -EINVAL;
 217         dom_name_len = strlen(ses->domainName);
 218         if(dom_name_len > MAX_USERNAME_SIZE)
 219                 return -EINVAL;
 220
 221         ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
 222         if(ucase_buf == NULL)
 223                 return -ENOMEM;
 224         unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
 225         if(unicode_buf == NULL) {
 226                 kfree(ucase_buf);
 227                 return -ENOMEM;
 228         }
 229
 230         for(i=0;i<user_name_len;i++)
 231                 ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
 232         ucase_buf[i] = 0;
 233         user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
 234         unicode_buf[user_name_len] = 0;
 235         user_name_len++;
 236
 237         for(i=0;i<dom_name_len;i++)
 238                 ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
 239         ucase_buf[i] = 0;
 240         dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
 241
 242         unicode_buf[user_name_len + dom_name_len] = 0;
 243         hmac_md5_update((const unsigned char *) unicode_buf,
 244                 (user_name_len+dom_name_len)*2,&ctx);
 245
 246         hmac_md5_final(ses->server->mac_signing_key,&ctx);
 247         kfree(ucase_buf);
 248         kfree(unicode_buf);
 249         return 0;
 250 }
 251 void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
 252 {
 253         struct HMACMD5Context context;
 254         memcpy(v2_session_response + 8, ses->server->cryptKey,8);
 255         /* gen_blob(v2_session_response + 16); */
 256         hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context);
 257
 258         hmac_md5_update(ses->server->cryptKey,8,&context);
 259 /*      hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */
 260
 261         hmac_md5_final(v2_session_response,&context);
 262 }