power: improve inline asm memory constraints

[linux/fpc-iii.git] / fs / cifs / cifsencrypt.c

/*
 *   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);
        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); */
}