libsmb/ntlm_check.c

ソースコードを見る。

関数
static BOOL	smb_pwd_check_ntlmv1 (const DATA_BLOB *nt_response, const uchar *part_passwd, const DATA_BLOB *sec_blob, DATA_BLOB *user_sess_key)
static BOOL	smb_pwd_check_ntlmv2 (const DATA_BLOB *ntv2_response, const uchar *part_passwd, const DATA_BLOB *sec_blob, const char *user, const char *domain, BOOL upper_case_domain, DATA_BLOB *user_sess_key)
NTSTATUS	ntlm_password_check (TALLOC_CTX *mem_ctx, const DATA_BLOB *challenge, const DATA_BLOB *lm_response, const DATA_BLOB *nt_response, const DATA_BLOB *lm_interactive_pwd, const DATA_BLOB *nt_interactive_pwd, const char *username, const char *client_username, const char *client_domain, const uint8 *lm_pw, const uint8 *nt_pw, DATA_BLOB *user_sess_key, DATA_BLOB *lm_sess_key)
	Check a challenge-response password against the value of the NT or LM password hash.

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関数

static BOOL smb_pwd_check_ntlmv1	(	const DATA_BLOB *	nt_response,
		const uchar *	part_passwd,
		const DATA_BLOB *	sec_blob,
		DATA_BLOB *	user_sess_key
	)			[static]

ntlm_check.c の 33 行で定義されています。

参照先 data_blob_::data・data_blob()・dump_data()・data_blob_::length・SMBOWFencrypt()・SMBsesskeygen_ntv1().

参照元 ntlm_password_check().

{
        /* Finish the encryption of part_passwd. */
        uchar p24[24];
        
        if (part_passwd == NULL) {
                DEBUG(10,("No password set - DISALLOWING access\n"));
                /* No password set - always false ! */
                return False;
        }
        
        if (sec_blob->length != 8) {
                DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect challenge size (%lu)\n", 
                          (unsigned long)sec_blob->length));
                return False;
        }
        
        if (nt_response->length != 24) {
                DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect password length (%lu)\n", 
                          (unsigned long)nt_response->length));
                return False;
        }

        SMBOWFencrypt(part_passwd, sec_blob->data, p24);
        if (user_sess_key != NULL) {
                *user_sess_key = data_blob(NULL, 16);
                SMBsesskeygen_ntv1(part_passwd, NULL, user_sess_key->data);
        }
        
        
#ifdef DEBUG_PASSWORD
        DEBUG(100,("Part password (P16) was |\n"));
        dump_data(100, (const char *)part_passwd, 16);
        DEBUGADD(100,("Password from client was |\n"));
        dump_data(100, (const char *)nt_response->data, nt_response->length);
        DEBUGADD(100,("Given challenge was |\n"));
        dump_data(100, (const char *)sec_blob->data, sec_blob->length);
        DEBUGADD(100,("Value from encryption was |\n"));
        dump_data(100, (const char *)p24, 24);
#endif
        return (memcmp(p24, nt_response->data, 24) == 0);
}

static BOOL smb_pwd_check_ntlmv2	(	const DATA_BLOB *	ntv2_response,
		const uchar *	part_passwd,
		const DATA_BLOB *	sec_blob,
		const char *	user,
		const char *	domain,
		BOOL	upper_case_domain,
		DATA_BLOB *	user_sess_key
	)			[static]

ntlm_check.c の 84 行で定義されています。

参照先 data_blob_::data・data_blob()・data_blob_clear_free()・dump_data()・data_blob_::length・ntv2_owf_gen()・SMBOWFencrypt_ntv2()・SMBsesskeygen_ntv2().

参照元 ntlm_password_check().

{
        /* Finish the encryption of part_passwd. */
        uchar kr[16];
        uchar value_from_encryption[16];
        uchar client_response[16];
        DATA_BLOB client_key_data;
        BOOL res;

        if (part_passwd == NULL) {
                DEBUG(10,("No password set - DISALLOWING access\n"));
                /* No password set - always False */
                return False;
        }

        if (sec_blob->length != 8) {
                DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect challenge size (%lu)\n", 
                          (unsigned long)sec_blob->length));
                return False;
        }
        
        if (ntv2_response->length < 24) {
                /* We MUST have more than 16 bytes, or the stuff below will go
                   crazy.  No known implementation sends less than the 24 bytes
                   for LMv2, let alone NTLMv2. */
                DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n", 
                          (unsigned long)ntv2_response->length));
                return False;
        }

        client_key_data = data_blob(ntv2_response->data+16, ntv2_response->length-16);
        /* 
           todo:  should we be checking this for anything?  We can't for LMv2, 
           but for NTLMv2 it is meant to contain the current time etc.
        */

        memcpy(client_response, ntv2_response->data, sizeof(client_response));

        if (!ntv2_owf_gen(part_passwd, user, domain, upper_case_domain, kr)) {
                return False;
        }

        SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption);
        if (user_sess_key != NULL) {
                *user_sess_key = data_blob(NULL, 16);
                SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data);
        }

#if DEBUG_PASSWORD
        DEBUG(100,("Part password (P16) was |\n"));
        dump_data(100, (const char *)part_passwd, 16);
        DEBUGADD(100,("Password from client was |\n"));
        dump_data(100, (const char *)ntv2_response->data, ntv2_response->length);
        DEBUGADD(100,("Variable data from client was |\n"));
        dump_data(100, (const char *)client_key_data.data, client_key_data.length);
        DEBUGADD(100,("Given challenge was |\n"));
        dump_data(100, (const char *)sec_blob->data, sec_blob->length);
        DEBUGADD(100,("Value from encryption was |\n"));
        dump_data(100, (const char *)value_from_encryption, 16);
#endif
        data_blob_clear_free(&client_key_data);
        res = (memcmp(value_from_encryption, client_response, 16) == 0);
        if ((!res) && (user_sess_key != NULL))
                data_blob_clear_free(user_sess_key);
        return res;
}

NTSTATUS ntlm_password_check	(	TALLOC_CTX *	mem_ctx,
		const DATA_BLOB *	challenge,
		const DATA_BLOB *	lm_response,
		const DATA_BLOB *	nt_response,
		const DATA_BLOB *	lm_interactive_pwd,
		const DATA_BLOB *	nt_interactive_pwd,
		const char *	username,
		const char *	client_username,
		const char *	client_domain,
		const uint8 *	lm_pw,
		const uint8 *	nt_pw,
		DATA_BLOB *	user_sess_key,
		DATA_BLOB *	lm_sess_key
	)

Check a challenge-response password against the value of the NT or LM password hash.

引数:

	mem_ctx	talloc context
	challenge	8-byte challenge. If all zero, forces plaintext comparison
	nt_response	'unicode' NT response to the challenge, or unicode password
	lm_response	ASCII or LANMAN response to the challenge, or password in DOS code page
	username	internal Samba username, for log messages
	client_username	username the client used
	client_domain	domain name the client used (may be mapped)
	nt_pw	MD4 unicode password from our passdb or similar
	lm_pw	LANMAN ASCII password from our passdb or similar
	user_sess_key	User session key
	lm_sess_key	LM session key (first 8 bytes of the LM hash)

ntlm_check.c の 173 行で定義されています。

参照先 data_blob_::data・data_blob()・E_P16()・data_blob_::length・mdfour()・smb_pwd_check_ntlmv1()・smb_pwd_check_ntlmv2()・SMBsesskeygen_ntv1().

参照元 local_pw_check()・sam_password_ok().

{
        static const unsigned char zeros[8] = { 0, };
        if (nt_pw == NULL) {
                DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n", 
                         username));
        }

        if (nt_interactive_pwd && nt_interactive_pwd->length && nt_pw) { 
                if (nt_interactive_pwd->length != 16) {
                        DEBUG(3,("ntlm_password_check: Interactive logon: Invalid NT password length (%d) supplied for user %s\n", (int)nt_interactive_pwd->length,
                                 username));
                        return NT_STATUS_WRONG_PASSWORD;
                }

                if (memcmp(nt_interactive_pwd->data, nt_pw, 16) == 0) {
                        if (user_sess_key) {
                                *user_sess_key = data_blob(NULL, 16);
                                SMBsesskeygen_ntv1(nt_pw, NULL, user_sess_key->data);
                        }
                        return NT_STATUS_OK;
                } else {
                        DEBUG(3,("ntlm_password_check: Interactive logon: NT password check failed for user %s\n",
                                 username));
                        return NT_STATUS_WRONG_PASSWORD;
                }

        } else if (lm_interactive_pwd && lm_interactive_pwd->length && lm_pw) { 
                if (lm_interactive_pwd->length != 16) {
                        DEBUG(3,("ntlm_password_check: Interactive logon: Invalid LANMAN password length (%d) supplied for user %s\n", (int)lm_interactive_pwd->length,
                                 username));
                        return NT_STATUS_WRONG_PASSWORD;
                }

                if (!lp_lanman_auth()) {
                        DEBUG(3,("ntlm_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n",
                                 username));
                        return NT_STATUS_WRONG_PASSWORD;
                }

                if (memcmp(lm_interactive_pwd->data, lm_pw, 16) == 0) {
                        return NT_STATUS_OK;
                } else {
                        DEBUG(3,("ntlm_password_check: Interactive logon: LANMAN password check failed for user %s\n",
                                 username));
                        return NT_STATUS_WRONG_PASSWORD;
                }
        }

        /* Check for cleartext netlogon. Used by Exchange 5.5. */
        if (challenge->length == sizeof(zeros) && 
            (memcmp(challenge->data, zeros, challenge->length) == 0 )) {

                DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
                         username));
                if (nt_pw && nt_response->length) {
                        unsigned char pwhash[16];
                        mdfour(pwhash, nt_response->data, nt_response->length);
                        if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
                                return NT_STATUS_OK;
                        } else {
                                DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n",
                                         username));
                                return NT_STATUS_WRONG_PASSWORD;
                        }

                } else if (!lp_lanman_auth()) {
                        DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
                                 username));

                } else if (lm_pw && lm_response->length) {
                        uchar dospwd[14]; 
                        uchar p16[16]; 
                        ZERO_STRUCT(dospwd);
                        
                        memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
                        /* Only the fisrt 14 chars are considered, password need not be null terminated. */

                        /* we *might* need to upper-case the string here */
                        E_P16((const unsigned char *)dospwd, p16);

                        if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
                                return NT_STATUS_OK;
                        } else {
                                DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n",
                                         username));
                                return NT_STATUS_WRONG_PASSWORD;
                        }
                } else {
                        DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
                        return NT_STATUS_WRONG_PASSWORD;
                }
        }

        if (nt_response->length != 0 && nt_response->length < 24) {
                DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n", 
                         (unsigned long)nt_response->length, username));                
        }
        
        if (nt_response->length >= 24 && nt_pw) {
                if (nt_response->length > 24) {
                        /* We have the NT MD4 hash challenge available - see if we can
                           use it 
                        */
                        DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain));
                        if (smb_pwd_check_ntlmv2( nt_response, 
                                                  nt_pw, challenge, 
                                                  client_username, 
                                                  client_domain,
                                                  False,
                                                  user_sess_key)) {
                                return NT_STATUS_OK;
                        }
                        
                        DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with uppercased version of domain [%s]\n", client_domain));
                        if (smb_pwd_check_ntlmv2( nt_response, 
                                                  nt_pw, challenge, 
                                                  client_username, 
                                                  client_domain,
                                                  True,
                                                  user_sess_key)) {
                                return NT_STATUS_OK;
                        }
                        
                        DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n"));
                        if (smb_pwd_check_ntlmv2( nt_response, 
                                                  nt_pw, challenge, 
                                                  client_username, 
                                                  "",
                                                  False,
                                                  user_sess_key)) {
                                return NT_STATUS_OK;
                        } else {
                                DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
                                return NT_STATUS_WRONG_PASSWORD;
                        }
                }

                if (lp_ntlm_auth()) {           
                        /* We have the NT MD4 hash challenge available - see if we can
                           use it (ie. does it exist in the smbpasswd file).
                        */
                        DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
                        if (smb_pwd_check_ntlmv1(nt_response, 
                                                 nt_pw, challenge,
                                                 user_sess_key)) {
                                /* The LM session key for this response is not very secure, 
                                   so use it only if we otherwise allow LM authentication */

                                if (lp_lanman_auth() && lm_pw) {
                                        uint8 first_8_lm_hash[16];
                                        memcpy(first_8_lm_hash, lm_pw, 8);
                                        memset(first_8_lm_hash + 8, '\0', 8);
                                        if (lm_sess_key) {
                                                *lm_sess_key = data_blob(first_8_lm_hash, 16);
                                        }
                                }
                                return NT_STATUS_OK;
                        } else {
                                DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
                                         username));
                                return NT_STATUS_WRONG_PASSWORD;
                        }
                } else {
                        DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
                                 username));                    
                        /* no return, becouse we might pick up LMv2 in the LM field */
                }
        }
        
        if (lm_response->length == 0) {
                DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
                         username));
                return NT_STATUS_WRONG_PASSWORD;
        }
        
        if (lm_response->length < 24) {
                DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n", 
                         (unsigned long)nt_response->length, username));                
                return NT_STATUS_WRONG_PASSWORD;
        }
                
        if (!lp_lanman_auth()) {
                DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
                         username));
        } else if (!lm_pw) {
                DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
                         username));
        } else {
                DEBUG(4,("ntlm_password_check: Checking LM password\n"));
                if (smb_pwd_check_ntlmv1(lm_response, 
                                         lm_pw, challenge,
                                         NULL)) {
                        uint8 first_8_lm_hash[16];
                        memcpy(first_8_lm_hash, lm_pw, 8);
                        memset(first_8_lm_hash + 8, '\0', 8);
                        if (user_sess_key) {
                                *user_sess_key = data_blob(first_8_lm_hash, 16);
                        }

                        if (lm_sess_key) {
                                *lm_sess_key = data_blob(first_8_lm_hash, 16);
                        }
                        return NT_STATUS_OK;
                }
        }
        
        if (!nt_pw) {
                DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username));
                return NT_STATUS_WRONG_PASSWORD;
        }
        
        /* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
           - related to Win9X, legacy NAS pass-though authentication
        */
        DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n", client_domain));
        if (smb_pwd_check_ntlmv2( lm_response, 
                                  nt_pw, challenge, 
                                  client_username,
                                  client_domain,
                                  False,
                                  NULL)) {
                return NT_STATUS_OK;
        }
        
        DEBUG(4,("ntlm_password_check: Checking LMv2 password with upper-cased version of domain %s\n", client_domain));
        if (smb_pwd_check_ntlmv2( lm_response, 
                                  nt_pw, challenge, 
                                  client_username,
                                  client_domain,
                                  True,
                                  NULL)) {
                return NT_STATUS_OK;
        }
        
        DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
        if (smb_pwd_check_ntlmv2( lm_response, 
                                  nt_pw, challenge, 
                                  client_username,
                                  "",
                                  False,
                                  NULL)) {
                return NT_STATUS_OK;
        }

        /* Apparently NT accepts NT responses in the LM field
           - I think this is related to Win9X pass-though authentication
        */
        DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
        if (lp_ntlm_auth()) {
                if (smb_pwd_check_ntlmv1(lm_response, 
                                         nt_pw, challenge,
                                         NULL)) {
                        /* The session key for this response is still very odd.  
                           It not very secure, so use it only if we otherwise 
                           allow LM authentication */

                        if (lp_lanman_auth() && lm_pw) {
                                uint8 first_8_lm_hash[16];
                                memcpy(first_8_lm_hash, lm_pw, 8);
                                memset(first_8_lm_hash + 8, '\0', 8);
                                if (user_sess_key) {
                                        *user_sess_key = data_blob(first_8_lm_hash, 16);
                                }

                                if (lm_sess_key) {
                                        *lm_sess_key = data_blob(first_8_lm_hash, 16);
                                }
                        }
                        return NT_STATUS_OK;
                }
                DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
        } else {
                DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
        }
        return NT_STATUS_WRONG_PASSWORD;
}

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