Length comparison of the linearized version is not correct.

[Samba/ekacnet.git] / source4 / libcli / auth / smbencrypt.c

/* 
   Unix SMB/CIFS implementation.
   SMB parameters and setup
   Copyright (C) Andrew Tridgell 1992-1998
   Modified by Jeremy Allison 1995.
   Copyright (C) Jeremy Allison 1995-2000.
   Copyright (C) Luke Kennethc Casson Leighton 1996-2000.
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program 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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "system/time.h"
#include "auth/ntlmssp/ntlmssp.h"
#include "auth/ntlmssp/msrpc_parse.h"
#include "../lib/crypto/crypto.h"
#include "libcli/auth/libcli_auth.h"

/*
   This implements the X/Open SMB password encryption
   It takes a password ('unix' string), a 8 byte "crypt key" 
   and puts 24 bytes of encrypted password into p24 

   Returns false if password must have been truncated to create LM hash
*/
bool SMBencrypt(const char *passwd, const uint8_t *c8, uint8_t p24[24])
{
        bool ret;
        uint8_t p21[21];

        memset(p21,'\0',21);
        ret = E_deshash(passwd, p21); 

        SMBOWFencrypt(p21, c8, p24);

#ifdef DEBUG_PASSWORD
        DEBUG(100,("SMBencrypt: lm#, challenge, response\n"));
        dump_data(100, p21, 16);
        dump_data(100, c8, 8);
        dump_data(100, p24, 24);
#endif

        return ret;
}

/**
 * Creates the MD4 Hash of the users password in NT UNICODE.
 * @param passwd password in 'unix' charset.
 * @param p16 return password hashed with md4, caller allocated 16 byte buffer
 */
 
bool E_md4hash(const char *passwd, uint8_t p16[16])
{
        int len;
        void *wpwd;

        len = push_ucs2_talloc(NULL, &wpwd, passwd);
        if (len < 2) {
                /* We don't want to return fixed data, as most callers
                 * don't check */
                mdfour(p16, (const uint8_t *)passwd, strlen(passwd));
                return false;
        }
        
        len -= 2;
        mdfour(p16, wpwd, len);

        talloc_free(wpwd);
        return true;
}

/**
 * Creates the DES forward-only Hash of the users password in DOS ASCII charset
 * @param passwd password in 'unix' charset.
 * @param p16 return password hashed with DES, caller allocated 16 byte buffer
 * @return false if password was > 14 characters, and therefore may be incorrect, otherwise true
 * @note p16 is filled in regardless
 */
 
bool E_deshash(const char *passwd, uint8_t p16[16])
{
        bool ret = true;
        char dospwd[256];
        ZERO_STRUCT(dospwd);

        /* Password must be converted to DOS charset - null terminated, uppercase. */
        push_string(dospwd, passwd, sizeof(dospwd), STR_ASCII|STR_UPPER|STR_TERMINATE);

        /* Only the first 14 chars are considered, password need not be null terminated. */
        E_P16((const uint8_t *)dospwd, p16);

        if (strlen(dospwd) > 14) {
                ret = false;
        }

        ZERO_STRUCT(dospwd);    

        return ret;
}

/* Does both the NTLMv2 owfs of a user's password */
bool ntv2_owf_gen(const uint8_t owf[16],
                  const char *user_in, const char *domain_in,
                  bool upper_case_domain, /* Transform the domain into UPPER case */
                  uint8_t kr_buf[16])
{
        void *user;
        void *domain;   
        size_t user_byte_len;
        size_t domain_byte_len;

        HMACMD5Context ctx;
        TALLOC_CTX *mem_ctx = talloc_init("ntv2_owf_gen for %s\\%s", domain_in, user_in); 

        if (!mem_ctx) {
                return false;
        }

        if (!user_in) {
                user_in = "";
        }

        if (!domain_in) {
                domain_in = "";
        }

        user_in = strupper_talloc(mem_ctx, user_in);
        if (user_in == NULL) {
                talloc_free(mem_ctx);
                return false;
        }

        if (upper_case_domain) {
                domain_in = strupper_talloc(mem_ctx, domain_in);
                if (domain_in == NULL) {
                        talloc_free(mem_ctx);
                        return false;
                }
        }

        user_byte_len = push_ucs2_talloc(mem_ctx, &user, user_in);
        if (user_byte_len == (ssize_t)-1) {
                DEBUG(0, ("push_uss2_talloc() for user returned -1 (probably talloc() failure)\n"));
                talloc_free(mem_ctx);
                return false;
        }

        domain_byte_len = push_ucs2_talloc(mem_ctx, &domain, domain_in);
        if (domain_byte_len == (ssize_t)-1) {
                DEBUG(0, ("push_ucs2_talloc() for domain returned -1 (probably talloc() failure)\n"));
                talloc_free(mem_ctx);
                return false;
        }

        SMB_ASSERT(user_byte_len >= 2);
        SMB_ASSERT(domain_byte_len >= 2);

        /* We don't want null termination */
        user_byte_len = user_byte_len - 2;
        domain_byte_len = domain_byte_len - 2;
        
        hmac_md5_init_limK_to_64(owf, 16, &ctx);
        hmac_md5_update(user, user_byte_len, &ctx);
        hmac_md5_update(domain, domain_byte_len, &ctx);
        hmac_md5_final(kr_buf, &ctx);

#ifdef DEBUG_PASSWORD
        DEBUG(100, ("ntv2_owf_gen: user, domain, owfkey, kr\n"));
        dump_data(100, user, user_byte_len);
        dump_data(100, domain, domain_byte_len);
        dump_data(100, owf, 16);
        dump_data(100, kr_buf, 16);
#endif

        talloc_free(mem_ctx);
        return true;
}

/* Does the des encryption from the NT or LM MD4 hash. */
void SMBOWFencrypt(const uint8_t passwd[16], const uint8_t *c8, uint8_t p24[24])
{
        uint8_t p21[21];

        ZERO_STRUCT(p21);
 
        memcpy(p21, passwd, 16);    
        E_P24(p21, c8, p24);
}

/* Does the NT MD4 hash then des encryption. */
 
void SMBNTencrypt(const char *passwd, uint8_t *c8, uint8_t *p24)
{
        uint8_t p21[21];
 
        memset(p21,'\0',21);
 
        E_md4hash(passwd, p21);    
        SMBOWFencrypt(p21, c8, p24);

#ifdef DEBUG_PASSWORD
        DEBUG(100,("SMBNTencrypt: nt#, challenge, response\n"));
        dump_data(100, p21, 16);
        dump_data(100, c8, 8);
        dump_data(100, p24, 24);
#endif
}

/* Does the md5 encryption from the Key Response for NTLMv2. */
void SMBOWFencrypt_ntv2(const uint8_t kr[16],
                        const DATA_BLOB *srv_chal,
                        const DATA_BLOB *smbcli_chal,
                        uint8_t resp_buf[16])
{
        HMACMD5Context ctx;

        hmac_md5_init_limK_to_64(kr, 16, &ctx);
        hmac_md5_update(srv_chal->data, srv_chal->length, &ctx);
        hmac_md5_update(smbcli_chal->data, smbcli_chal->length, &ctx);
        hmac_md5_final(resp_buf, &ctx);

#ifdef DEBUG_PASSWORD
        DEBUG(100, ("SMBOWFencrypt_ntv2: srv_chal, smbcli_chal, resp_buf\n"));
        dump_data(100, srv_chal->data, srv_chal->length);
        dump_data(100, smbcli_chal->data, smbcli_chal->length);
        dump_data(100, resp_buf, 16);
#endif
}

void SMBsesskeygen_ntv2(const uint8_t kr[16],
                        const uint8_t * nt_resp, uint8_t sess_key[16])
{
        /* a very nice, 128 bit, variable session key */
        
        HMACMD5Context ctx;

        hmac_md5_init_limK_to_64(kr, 16, &ctx);
        hmac_md5_update(nt_resp, 16, &ctx);
        hmac_md5_final((uint8_t *)sess_key, &ctx);

#ifdef DEBUG_PASSWORD
        DEBUG(100, ("SMBsesskeygen_ntv2:\n"));
        dump_data(100, sess_key, 16);
#endif
}

void SMBsesskeygen_ntv1(const uint8_t kr[16], uint8_t sess_key[16])
{
        /* yes, this session key does not change - yes, this 
           is a problem - but it is 128 bits */
        
        mdfour((uint8_t *)sess_key, kr, 16);

#ifdef DEBUG_PASSWORD
        DEBUG(100, ("SMBsesskeygen_ntv1:\n"));
        dump_data(100, sess_key, 16);
#endif
}

void SMBsesskeygen_lm_sess_key(const uint8_t lm_hash[16],
                               const uint8_t lm_resp[24], /* only uses 8 */ 
                               uint8_t sess_key[16])
{
        /* Calculate the LM session key (effective length 40 bits,
           but changes with each session) */
        uint8_t p24[24];
        uint8_t partial_lm_hash[14];
 
        memcpy(partial_lm_hash, lm_hash, 8);    
        memset(partial_lm_hash + 8, 0xbd, 6);

        des_crypt56(p24,   lm_resp, partial_lm_hash,     1);
        des_crypt56(p24+8, lm_resp, partial_lm_hash + 7, 1);

        memcpy(sess_key, p24, 16);

#ifdef DEBUG_PASSWORD
        DEBUG(100, ("SMBsesskeygen_lm_sess_key: \n"));
        dump_data(100, sess_key, 16);
#endif
}

DATA_BLOB NTLMv2_generate_names_blob(TALLOC_CTX *mem_ctx, 
                                     const char *hostname, 
                                     const char *domain)
{
        DATA_BLOB names_blob = data_blob_talloc(mem_ctx, NULL, 0);
        
        msrpc_gen(mem_ctx, &names_blob, 
                  "aaa", 
                  NTLMSSP_NAME_TYPE_DOMAIN, domain,
                  NTLMSSP_NAME_TYPE_SERVER, hostname,
                  0, "");
        return names_blob;
}

static DATA_BLOB NTLMv2_generate_client_data(TALLOC_CTX *mem_ctx, const DATA_BLOB *names_blob) 
{
        uint8_t client_chal[8];
        DATA_BLOB response = data_blob(NULL, 0);
        uint8_t long_date[8];
        NTTIME nttime;

        unix_to_nt_time(&nttime, time(NULL));

        generate_random_buffer(client_chal, sizeof(client_chal));

        push_nttime(long_date, 0, nttime);

        /* See http://www.ubiqx.org/cifs/SMB.html#SMB.8.5 */

        msrpc_gen(mem_ctx, &response, "ddbbdb", 
                  0x00000101,     /* Header  */
                  0,              /* 'Reserved'  */
                  long_date, 8,   /* Timestamp */
                  client_chal, 8, /* client challenge */
                  0,              /* Unknown */
                  names_blob->data, names_blob->length);        /* End of name list */

        return response;
}

static DATA_BLOB NTLMv2_generate_response(TALLOC_CTX *out_mem_ctx, 
                                          const uint8_t ntlm_v2_hash[16],
                                          const DATA_BLOB *server_chal,
                                          const DATA_BLOB *names_blob)
{
        uint8_t ntlmv2_response[16];
        DATA_BLOB ntlmv2_client_data;
        DATA_BLOB final_response;
        
        TALLOC_CTX *mem_ctx = talloc_named(out_mem_ctx, 0, 
                                           "NTLMv2_generate_response internal context");

        if (!mem_ctx) {
                return data_blob(NULL, 0);
        }
        
        /* NTLMv2 */
        /* generate some data to pass into the response function - including
           the hostname and domain name of the server */
        ntlmv2_client_data = NTLMv2_generate_client_data(mem_ctx, names_blob);

        /* Given that data, and the challenge from the server, generate a response */
        SMBOWFencrypt_ntv2(ntlm_v2_hash, server_chal, &ntlmv2_client_data, ntlmv2_response);
        
        final_response = data_blob_talloc(out_mem_ctx, NULL, sizeof(ntlmv2_response) + ntlmv2_client_data.length);

        memcpy(final_response.data, ntlmv2_response, sizeof(ntlmv2_response));

        memcpy(final_response.data+sizeof(ntlmv2_response), 
               ntlmv2_client_data.data, ntlmv2_client_data.length);

        talloc_free(mem_ctx);

        return final_response;
}

static DATA_BLOB LMv2_generate_response(TALLOC_CTX *mem_ctx, 
                                        const uint8_t ntlm_v2_hash[16],
                                        const DATA_BLOB *server_chal)
{
        uint8_t lmv2_response[16];
        DATA_BLOB lmv2_client_data = data_blob_talloc(mem_ctx, NULL, 8);
        DATA_BLOB final_response = data_blob_talloc(mem_ctx, NULL,24);
        
        /* LMv2 */
        /* client-supplied random data */
        generate_random_buffer(lmv2_client_data.data, lmv2_client_data.length); 

        /* Given that data, and the challenge from the server, generate a response */
        SMBOWFencrypt_ntv2(ntlm_v2_hash, server_chal, &lmv2_client_data, lmv2_response);
        memcpy(final_response.data, lmv2_response, sizeof(lmv2_response));

        /* after the first 16 bytes is the random data we generated above, 
           so the server can verify us with it */
        memcpy(final_response.data+sizeof(lmv2_response), 
               lmv2_client_data.data, lmv2_client_data.length);

        data_blob_free(&lmv2_client_data);

        return final_response;
}

bool SMBNTLMv2encrypt_hash(TALLOC_CTX *mem_ctx, 
                           const char *user, const char *domain, const uint8_t nt_hash[16],
                           const DATA_BLOB *server_chal, 
                           const DATA_BLOB *names_blob,
                           DATA_BLOB *lm_response, DATA_BLOB *nt_response, 
                           DATA_BLOB *lm_session_key, DATA_BLOB *user_session_key) 
{
        uint8_t ntlm_v2_hash[16];

        /* We don't use the NT# directly.  Instead we use it mashed up with
           the username and domain.
           This prevents username swapping during the auth exchange
        */
        if (!ntv2_owf_gen(nt_hash, user, domain, true, ntlm_v2_hash)) {
                return false;
        }
        
        if (nt_response) {
                *nt_response = NTLMv2_generate_response(mem_ctx, 
                                                        ntlm_v2_hash, server_chal,
                                                        names_blob); 
                if (user_session_key) {
                        *user_session_key = data_blob_talloc(mem_ctx, NULL, 16);
                        
                        /* The NTLMv2 calculations also provide a session key, for signing etc later */
                        /* use only the first 16 bytes of nt_response for session key */
                        SMBsesskeygen_ntv2(ntlm_v2_hash, nt_response->data, user_session_key->data);
                }
        }
        
        /* LMv2 */
        
        if (lm_response) {
                *lm_response = LMv2_generate_response(mem_ctx, 
                                                      ntlm_v2_hash, server_chal);
                if (lm_session_key) {
                        *lm_session_key = data_blob_talloc(mem_ctx, NULL, 16);
                        
                        /* The NTLMv2 calculations also provide a session key, for signing etc later */
                        /* use only the first 16 bytes of lm_response for session key */
                        SMBsesskeygen_ntv2(ntlm_v2_hash, lm_response->data, lm_session_key->data);
                }
        }
        
        return true;
}

bool SMBNTLMv2encrypt(TALLOC_CTX *mem_ctx, 
                      const char *user, const char *domain, 
                      const char *password, 
                      const DATA_BLOB *server_chal, 
                      const DATA_BLOB *names_blob,
                      DATA_BLOB *lm_response, DATA_BLOB *nt_response, 
                      DATA_BLOB *lm_session_key, DATA_BLOB *user_session_key) 
{
        uint8_t nt_hash[16];
        E_md4hash(password, nt_hash);

        return SMBNTLMv2encrypt_hash(mem_ctx, 
                                     user, domain, nt_hash, server_chal, names_blob,
                                     lm_response, nt_response, lm_session_key, user_session_key);
}

/***********************************************************
 encode a password buffer with a unicode password.  The buffer
 is filled with random data to make it harder to attack.
************************************************************/
bool encode_pw_buffer(uint8_t buffer[516], const char *password, int string_flags)
{
        uint8_t new_pw[512];
        size_t new_pw_len;

        /* the incoming buffer can be any alignment. */
        string_flags |= STR_NOALIGN;

        new_pw_len = push_string(new_pw,
                                 password, 
                                 sizeof(new_pw), string_flags);
        
        memcpy(&buffer[512 - new_pw_len], new_pw, new_pw_len);

        generate_random_buffer(buffer, 512 - new_pw_len);

        /* 
         * The length of the new password is in the last 4 bytes of
         * the data buffer.
         */
        SIVAL(buffer, 512, new_pw_len);
        ZERO_STRUCT(new_pw);
        return true;
}


/***********************************************************
 decode a password buffer
 *new_pw_len is the length in bytes of the possibly mulitbyte
 returned password including termination.
************************************************************/
bool decode_pw_buffer(uint8_t in_buffer[516], char *new_pwrd,
                      int new_pwrd_size, int string_flags)
{
        int byte_len=0;
        ssize_t converted_pw_len;

        /* the incoming buffer can be any alignment. */
        string_flags |= STR_NOALIGN;

        /*
          Warning !!! : This function is called from some rpc call.
          The password IN the buffer may be a UNICODE string.
          The password IN new_pwrd is an ASCII string
          If you reuse that code somewhere else check first.
        */

        /* The length of the new password is in the last 4 bytes of the data buffer. */

        byte_len = IVAL(in_buffer, 512);

#ifdef DEBUG_PASSWORD
        dump_data(100, in_buffer, 516);
#endif

        /* Password cannot be longer than the size of the password buffer */
        if ( (byte_len < 0) || (byte_len > 512)) {
                return false;
        }

        /* decode into the return buffer.  Buffer length supplied */
        converted_pw_len = pull_string(new_pwrd, &in_buffer[512 - byte_len], new_pwrd_size, 
                                  byte_len, string_flags);

        if (converted_pw_len == -1) {
                return false;
        }

#ifdef DEBUG_PASSWORD
        DEBUG(100,("decode_pw_buffer: new_pwrd: "));
        dump_data(100, (const uint8_t *)new_pwrd, converted_pw_len);
        DEBUG(100,("multibyte len:%d\n", (int)converted_pw_len));
        DEBUG(100,("original char len:%d\n", byte_len/2));
#endif
        
        return true;
}

/***********************************************************
 encode a password buffer with an already unicode password.  The
 rest of the buffer is filled with random data to make it harder to attack.
************************************************************/
bool set_pw_in_buffer(uint8_t buffer[516], DATA_BLOB *password)
{
        if (password->length > 512) {
                return false;
        }

        memcpy(&buffer[512 - password->length], password->data, password->length);

        generate_random_buffer(buffer, 512 - password->length);

        /* 
         * The length of the new password is in the last 4 bytes of
         * the data buffer.
         */
        SIVAL(buffer, 512, password->length);
        return true;
}

/***********************************************************
 decode a password buffer
 *new_pw_size is the length in bytes of the extracted unicode password
************************************************************/
bool extract_pw_from_buffer(TALLOC_CTX *mem_ctx, 
                            uint8_t in_buffer[516], DATA_BLOB *new_pass)
{
        int byte_len=0;

        /* The length of the new password is in the last 4 bytes of the data buffer. */

        byte_len = IVAL(in_buffer, 512);

#ifdef DEBUG_PASSWORD
        dump_data(100, in_buffer, 516);
#endif

        /* Password cannot be longer than the size of the password buffer */
        if ( (byte_len < 0) || (byte_len > 512)) {
                return false;
        }

        *new_pass = data_blob_talloc(mem_ctx, &in_buffer[512 - byte_len], byte_len);

        if (!*new_pass->data) {
                return false;
        }

        return true;
}