/*
 * snmpv3.c
 */

#include <config.h>

#include <stdio.h>
#include <sys/types.h>
#if TIME_WITH_SYS_TIME
# ifdef WIN32
#  include <sys/timeb.h>
# else
#  include <sys/time.h>
# endif
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_WINSOCK_H
#include <winsock.h>
#endif
#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if HAVE_NETDB_H
#include <netdb.h>
#endif
#if HAVE_STDLIB_H
#       include <stdlib.h>
#endif

/* Stuff needed for getHwAddress(...) */
#ifdef HAVE_SYS_IOCTL_H
#	include <sys/ioctl.h>
#endif
#ifdef HAVE_NET_IF_H
#	include <net/if.h>
#endif

#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif

#include "system.h"
#include "asn1.h"
#include "snmpv3.h"
#include "callback.h"
#include "snmp.h"
#include "snmp_api.h"
#include "snmp_impl.h"
#include "read_config.h"
#include "lcd_time.h"
#include "scapi.h"
#include "tools.h"
#include "keytools.h"
#include "lcd_time.h"
#include "snmp_debug.h"
#include "snmp_logging.h"
#include "default_store.h"
#include "snmpusm.h"

#include "transform_oids.h"

static u_long		 engineBoots	   = 1;
static unsigned int	 engineIDType	   = ENGINEID_TYPE_UCD_RND;
static unsigned char	*engineID	   = NULL;
static size_t		 engineIDLength	   = 0;
static unsigned char	*engineIDNic	   = NULL;
static unsigned int	 engineIDIsSet	   = 0; /* flag if ID set by config */
static unsigned char	*oldEngineID	   = NULL;
static size_t		 oldEngineIDLength = 0;
static struct timeval	 snmpv3starttime;

/* 
 * Set up default snmpv3 parameter value storage.
 */
static oid	*defaultAuthType	= NULL;
static size_t	 defaultAuthTypeLen	= 0;
static oid	*defaultPrivType	= NULL;
static size_t	 defaultPrivTypeLen	= 0;

#if defined(IFHWADDRLEN) && defined(SIOCGIFHWADDR)
static int getHwAddress(const char * networkDevice, char * addressOut);
#endif

void
snmpv3_authtype_conf(const char *word, char *cptr)
{
  if (strcasecmp(cptr,"MD5") == 0)
    defaultAuthType = usmHMACMD5AuthProtocol;
  else if (strcasecmp(cptr,"SHA") == 0)
    defaultAuthType = usmHMACSHA1AuthProtocol;
  else
    config_perror("Unknown authentication type");
  defaultAuthTypeLen = USM_LENGTH_OID_TRANSFORM;
  DEBUGMSGTL(("snmpv3","set default authentication type: %s\n", cptr));
}

oid *
get_default_authtype(size_t *len)
{
  if (defaultAuthType == NULL) {
    defaultAuthType = SNMP_DEFAULT_AUTH_PROTO;
    defaultAuthTypeLen = SNMP_DEFAULT_AUTH_PROTOLEN;
  }
  if (len)
    *len = defaultAuthTypeLen;
  return defaultAuthType;
}

void
snmpv3_privtype_conf(const char *word, char *cptr)
{
  if (strcasecmp(cptr,"DES") == 0)
    defaultPrivType = SNMP_DEFAULT_PRIV_PROTO;
  else
    config_perror("Unknown privacy type");
  defaultPrivTypeLen = SNMP_DEFAULT_PRIV_PROTOLEN;
  DEBUGMSGTL(("snmpv3","set default privacy type: %s\n", cptr));
}

oid *
get_default_privtype(size_t *len)
{
  if (defaultPrivType == NULL) {
    defaultPrivType = usmDESPrivProtocol;
    defaultPrivTypeLen = USM_LENGTH_OID_TRANSFORM;
  }
  if (len)
    *len = defaultPrivTypeLen;
  return defaultPrivType;
}

/*******************************************************************-o-******
 * snmpv3_secLevel_conf
 *
 * Parameters:
 *	*word
 *	*cptr
 *
 * Line syntax:
 *	defSecurityLevel "noAuthNoPriv" | "authNoPriv" | "authPriv"
 */
void
snmpv3_secLevel_conf(const char *word, char *cptr)
{
  char buf[1024];
  
  if (strcasecmp(cptr,"noAuthNoPriv") == 0 || strcmp(cptr, "1") == 0
	|| strcasecmp(cptr, "nanp") == 0)
    ds_set_int(DS_LIBRARY_ID, DS_LIB_SECLEVEL, SNMP_SEC_LEVEL_NOAUTH);
  else if (strcasecmp(cptr,"authNoPriv") == 0 || strcmp(cptr, "2") == 0
	|| strcasecmp(cptr, "anp") == 0)
    ds_set_int(DS_LIBRARY_ID, DS_LIB_SECLEVEL, SNMP_SEC_LEVEL_AUTHNOPRIV);
  else if (strcasecmp(cptr,"authPriv") == 0 || strcmp(cptr, "3") == 0
	|| strcasecmp(cptr, "ap") == 0)
    ds_set_int(DS_LIBRARY_ID, DS_LIB_SECLEVEL, SNMP_SEC_LEVEL_AUTHPRIV);
  else {
    sprintf(buf,"Unknown security level: %s", cptr);
    config_perror(buf);
  }
  DEBUGMSGTL(("snmpv3","default secLevel set to: %s = %d\n", cptr,
              ds_get_int(DS_LIBRARY_ID, DS_LIB_SECLEVEL)));
}

/*******************************************************************-o-******
 * setup_engineID
 *
 * Parameters:
 *	**eidp
 *	 *text	Printable (?) text to be plugged into the snmpEngineID.
 *
 * Return:
 *	Length of allocated engineID string in bytes,  -OR-
 *	-1 on error.
 *
 *
 * Create an snmpEngineID using text and the local IP address.  If eidp
 * is defined, use it to return a pointer to the newly allocated data.
 * Otherwise, use the result to define engineID defined in this module.
 *
 * Line syntax:
 *	engineID <text> | NULL
 *
 * XXX	What if a node has multiple interfaces?
 * XXX	What if multiple engines all choose the same address?
 *      (answer:  You're screwed, because you might need a kul database
 *       which is dependant on the current engineID.  Enumeration and other
 *       tricks won't work). 
 */
int
setup_engineID(u_char **eidp, const char *text)
{
  int		  enterpriseid	= htonl(ENTERPRISE_NUMBER),
		  localsetup	= (eidp) ? 0 : 1;

			/* Use local engineID if *eidp == NULL.  */
#ifdef HAVE_GETHOSTNAME
  u_char	  buf[SNMP_MAXBUF_SMALL];
  struct hostent *hent;
#endif
  u_char     *bufp = NULL;
  size_t	  len;
  int	    localEngineIDType = engineIDType;
  int tmpint;
  time_t tmptime;
  
  engineIDIsSet = 1;
  
/* get the host name and save the information */
#ifdef HAVE_GETHOSTNAME
  gethostname((char *)buf, sizeof(buf));
  hent = gethostbyname((char *)buf);
/* Determine if we are using IPV6 */
#ifdef AF_INET6
  /* see if they selected IPV4 or IPV6 support */
  if ( (ENGINEID_TYPE_IPV6 == localEngineIDType ) || \
       (ENGINEID_TYPE_IPV4 == localEngineIDType ) )
  {
    if (hent && hent->h_addrtype == AF_INET6)
    {
      localEngineIDType=ENGINEID_TYPE_IPV6;
    }
    else
    {
      /* Not IPV6 so we go with default */
      localEngineIDType=ENGINEID_TYPE_IPV4;
    }
  }
#else
/* No IPV6 support.  Check if they selected IPV6 engineID type.  If so
 * make it IPV4 for them */
  if ( ENGINEID_TYPE_IPV6 == localEngineIDType )
  {
    localEngineIDType = ENGINEID_TYPE_IPV4;
  }
#endif
#endif /* HAVE_GETHOSTNAME */

  /* Determine if we have text and if so setup our localEngineIDType
   * appropriately.  */
  if ( NULL != text )
  {
      engineIDType = localEngineIDType = ENGINEID_TYPE_TEXT;
  }
  /* Determine length of the engineID string. */
  len = 5;  /* always have 5 leading bytes */
  switch(localEngineIDType)
  {
    case ENGINEID_TYPE_TEXT:
      len += strlen(text);	/* 5 leading bytes+text. No NULL char */
      break;
#if defined(IFHWADDRLEN) && defined(SIOCGIFHWADDR)
    case ENGINEID_TYPE_MACADDR: /* MAC address */
      len += 6;   /* + 6 bytes for MAC address */
      break;
#endif
    case ENGINEID_TYPE_IPV4: /* IPv4 */
      len +=4; /* + 4 byte IPV4 address */
      break;
    case ENGINEID_TYPE_IPV6: /* IPv6 */
      len += 16; /* + 16 byte IPV6 address */
      break;
    case ENGINEID_TYPE_UCD_RND: /* UCD specific encoding */
        if (engineID) /* already setup, keep current value */
            return engineIDLength;
        if (oldEngineID) {
            len = oldEngineIDLength;
        } else {
            len += sizeof(int) + sizeof(time_t);
        }
        break;
    default:
      snmp_log(LOG_ERR, "Unknown EngineID type requested for setup (%d).  Using IPv4.\n", localEngineIDType);
      localEngineIDType=ENGINEID_TYPE_IPV4; /* make into IPV4 */
      len += 4;		/* + 4 byte IPv4 address */
      break;
  } /* switch */


  /*
   * Allocate memory and store enterprise ID.
   */
  if ((bufp = (u_char *) malloc(len)) == NULL) {
    snmp_log_perror("setup_engineID malloc");
    return -1;
  }
  memcpy(bufp, &enterpriseid, sizeof(enterpriseid)); /* XXX Must be 4 bytes! */
  bufp[0] |= 0x80;
  

  /*
   * Store the given text  -OR-   the first found IP address.
   */
  switch (localEngineIDType)
  {
    case ENGINEID_TYPE_UCD_RND:
      if (oldEngineID) {
          /* keep our previous notion of the engineID */
          memcpy(bufp, oldEngineID, oldEngineIDLength);
      } else {
          /*
            Here we've desigend our own ENGINEID that is not based on
            an address which may change and may even become conflicting
            in the future like most of the default v3 engineID types
            suffer from.

            Ours is built from 2 fairly random elements: a random number and
            the current time in seconds.  This method suffers from boxes
            that may not have a correct clock setting and random number
            seed at startup, but few OSes should have that problem.
          */
          bufp[4] = ENGINEID_TYPE_UCD_RND;
          tmpint = random();
          memcpy(bufp+5, &tmpint, sizeof(tmpint));
          tmptime = time(NULL);
          memcpy(bufp+5+sizeof(tmpint), &tmptime, sizeof(tmptime));
      }
      break;
    case ENGINEID_TYPE_TEXT:
      bufp[4] = ENGINEID_TYPE_TEXT;
      memcpy((char *)bufp+5, text, strlen(text));
      break;
#ifdef HAVE_GETHOSTNAME
#ifdef AF_INET6
    case ENGINEID_TYPE_IPV6:
      bufp[4] = ENGINEID_TYPE_IPV6;
      memcpy(bufp+5, hent->h_addr_list[0], hent->h_length);
      break;
#endif
#endif
#if defined(IFHWADDRLEN) && defined(SIOCGIFHWADDR)
    case ENGINEID_TYPE_MACADDR:
	{ int x;
		bufp[4] = ENGINEID_TYPE_MACADDR;
		/* use default NIC if none provided */
		if ( NULL == engineIDNic )
		{
			x = getHwAddress(DEFAULT_NIC,&bufp[5]);
		}
		else
		{
			x = getHwAddress(engineIDNic,&bufp[5]);
		}
		if ( 0 != x)
		/* function failed fill MAC address with zeros */
		{
			memset(&bufp[5], 0, 6);
		}
	}
      break;
#endif
    case ENGINEID_TYPE_IPV4:
    default:
      bufp[4] = ENGINEID_TYPE_IPV4;
#ifdef HAVE_GETHOSTNAME
      if (hent && hent->h_addrtype == AF_INET)
      {
	memcpy(bufp+5, hent->h_addr_list[0], hent->h_length);
      }
      else /* Unknown address type.  Default to 127.0.0.1. */
      {
	bufp[5] = 127;
	bufp[6] = 0;
	bufp[7] = 0;
	bufp[8] = 1;
      }
#else /* HAVE_GETHOSTNAME */
      /* Unknown address type.  Default to 127.0.0.1. */
      bufp[5] = 127;
      bufp[6] = 0;
      bufp[7] = 0;
      bufp[8] = 1;
#endif /* HAVE_GETHOSTNAME */
      break;
  }

  /*
   * Pass the string back to the calling environment, or use it for
   * our local engineID.
   */
  if (localsetup) {
	SNMP_FREE(engineID);
	engineID	= bufp;
	engineIDLength	= len;

  } else {
	*eidp = bufp;
  }


  return len;

}  /* end setup_engineID() */

void
usm_parse_create_usmUser(const char *token, char *line) {
  char *cp;
  char buf[SNMP_MAXBUF_MEDIUM], buf2[SNMP_MAXBUF_SMALL];
  struct usmUser *newuser;
  u_char	  userKey[SNMP_MAXBUF_SMALL];
  size_t	  userKeyLen = SNMP_MAXBUF_SMALL;
  size_t ret;
  int    ret2;

  newuser = usm_create_user();

  /* READ: Security Name */
  cp = copy_word(line, buf);

  /* might be a -e ENGINEID argument */
  if (strcmp(buf,"-e") == 0) {
      /* get the specified engineid from the line */
      cp = copy_word(cp, buf);
      ret2 = hex_to_binary(buf, (u_char *)buf2);
      if (ret2 <= 0) {
          usm_free_user(newuser);
          config_perror("invalid EngineID argument to -e");
          return;
      }
      newuser->engineIDLen = ret2;
      memdup(&newuser->engineID, (u_char *)buf2, newuser->engineIDLen);
      cp = copy_word(cp, buf);
  } else {
      newuser->engineID = snmpv3_generate_engineID(&ret);
      if ( ret == 0 ) {
          usm_free_user(newuser);
          return;
      }
      newuser->engineIDLen = ret;
  }
  
  newuser->secName = strdup(buf);
  newuser->name = strdup(buf);

  if (!cp)
    goto add; /* no authentication or privacy type */

  /* READ: Authentication Type */
  if (strncmp(cp, "MD5", 3) == 0) {
    memcpy(newuser->authProtocol, usmHMACMD5AuthProtocol,
           sizeof(usmHMACMD5AuthProtocol));
  } else if (strncmp(cp, "SHA", 3) == 0) {
    memcpy(newuser->authProtocol, usmHMACSHA1AuthProtocol,
           sizeof(usmHMACSHA1AuthProtocol));
  } else {
    config_perror("Unknown authentication protocol");
    usm_free_user(newuser);
    return;
  }

  cp = skip_token(cp);

  /* READ: Authentication Pass Phrase */
  if (!cp) {
    config_perror("no authentication pass phrase");
    usm_free_user(newuser);
    return;
  }
  cp = copy_word(cp, buf);
  /* And turn it into a localized key */
  ret = generate_Ku(newuser->authProtocol, newuser->authProtocolLen,
		    (u_char *)buf, strlen(buf),
		    userKey, &userKeyLen );
  if (ret != SNMPERR_SUCCESS) {
    config_perror("Error generating auth key from pass phrase.");
    usm_free_user(newuser);
    return;
  }
  newuser->authKeyLen =
    sc_get_properlength(newuser->authProtocol, newuser->authProtocolLen);
  newuser->authKey = (u_char *) malloc(newuser->authKeyLen);
  ret = generate_kul(newuser->authProtocol, newuser->authProtocolLen,
		     newuser->engineID, newuser->engineIDLen,
		     userKey, userKeyLen,
		     newuser->authKey, &newuser->authKeyLen );
  if (ret != SNMPERR_SUCCESS) {
    config_perror("Error generating localized auth key (Kul) from Ku.");
    usm_free_user(newuser);
    return;
  }

  if (!cp)
    goto add; /* no privacy type (which is legal) */
  
  /* READ: Privacy Type */
  if (strncmp(cp, "DES", 3) == 0) {
    memcpy(newuser->privProtocol, usmDESPrivProtocol,
           sizeof(usmDESPrivProtocol));
  } else {
    config_perror("Unknown privacy protocol");
    usm_free_user(newuser);
    return;
  }

  cp = skip_token(cp);
  /* READ: Authentication Pass Phrase */
  if (!cp) {
    /* assume the same as the authentication key */
    memdup(&newuser->privKey, newuser->authKey, newuser->authKeyLen);
    newuser->privKeyLen = newuser->authKeyLen;
  } else {
    cp = copy_word(cp, buf);
    /* And turn it into a localized key */
    ret = generate_Ku(newuser->authProtocol, newuser->authProtocolLen,
                      (u_char *)buf, strlen(buf),
                      userKey, &userKeyLen );
    if (ret != SNMPERR_SUCCESS) {
      config_perror("Error generating priv key from pass phrase.");
      usm_free_user(newuser);
      return;
    }

    ret = sc_get_properlength(newuser->authProtocol, newuser->authProtocolLen);
    if (ret < 0) {
      config_perror("Error getting proper key length for priv algorithm.");
      usm_free_user(newuser);
      return;
    }
    newuser->privKeyLen = ret;
      
    newuser->privKey = (u_char *) malloc(newuser->privKeyLen);
    ret = generate_kul(newuser->authProtocol, newuser->authProtocolLen,
                       newuser->engineID, newuser->engineIDLen,
                       userKey, userKeyLen,
                       newuser->privKey, &newuser->privKeyLen );
    if (ret != SNMPERR_SUCCESS) {
      config_perror("Error generating localized priv key (Kul) from Ku.");
      usm_free_user(newuser);
      return;
    }
  }
add:
  usm_add_user(newuser);
  DEBUGMSGTL(("usmUser","created a new user %s at ", newuser->secName));
  DEBUGMSGHEX(("usmUser", newuser->engineID, newuser->engineIDLen));
  DEBUGMSG(("usmUser", "\n"));
}

/*******************************************************************-o-******
 * engineBoots_conf
 *
 * Parameters:
 *	*word
 *	*cptr
 *
 * Line syntax:
 *	engineBoots <num_boots>
 */
void
engineBoots_conf(const char *word, char *cptr)
{
  engineBoots = atoi(cptr)+1;
  DEBUGMSGTL(("snmpv3","engineBoots: %d\n",engineBoots));
}

/*******************************************************************-o-******
 * engineIDType_conf
 *
 * Parameters:
 *	*word
 *	*cptr
 *
 * Line syntax:
 *	engineIDType <1 or 3>
 *		1 is default for IPv4 engine ID type.  Will automatically
 *		    chose between IPv4 & IPv6 if either 1 or 2 is specified.
 *		2 is for IPv6.
 *		3 is hardware (MAC) address, currently supported under Linux
 */
void
engineIDType_conf(const char *word, char *cptr)
{
    engineIDType = atoi(cptr);
    /* verify valid type selected */
    switch (engineIDType) {
        case ENGINEID_TYPE_IPV4: /* IPv4 */
        case ENGINEID_TYPE_IPV6: /* IPv6 */
            /* IPV? is always good */
            break;
#if defined(IFHWADDRLEN) && defined(SIOCGIFHWADDR)
        case ENGINEID_TYPE_MACADDR: /* MAC address */
            break;
#endif
        default:
            /* unsupported one chosen */
            config_perror("Unsupported enginedIDType, forcing IPv4");
            engineIDType=ENGINEID_TYPE_IPV4;
    }
    DEBUGMSGTL(("snmpv3","engineIDType: %d\n",engineIDType));
}

/*******************************************************************-o-******
 * engineIDNic_conf
 *
 * Parameters:
 *	*word
 *	*cptr
 *
 * Line syntax:
 *	engineIDNic <string>
 *		eth0 is default
 */
void
engineIDNic_conf(const char *word, char *cptr)
{
  /* Make sure they haven't already specified the engineID via the
   * configuration file */
  if ( 0 == engineIDIsSet )
  /* engineID has NOT been set via configuration file */
  {
    /* See if already set if so erase & release it */
    if ( NULL != engineIDNic )
    {
      free(engineIDNic);
    }
    engineIDNic=(u_char *)malloc(strlen(cptr)+1);
    if ( NULL != engineIDNic )
    {
      strcpy((char *)engineIDNic,cptr);
      DEBUGMSGTL(("snmpv3","Initializing engineIDNic: %s\n", engineIDNic));
    }
    else
    {
      DEBUGMSGTL(("snmpv3","Error allocating memory for engineIDNic!\n"));
    }
  }
  else
  {
    DEBUGMSGTL(("snmpv3","NOT setting engineIDNic, engineID already set\n"));
  }
}

/*******************************************************************-o-******
 * engineID_conf
 *
 * Parameters:
 *	*word
 *	*cptr
 *
 * This function reads a string from the configuration file and uses that
 * string to initialize the engineID.  It's assumed to be human readable.
 */
void
engineID_conf(const char *word, char *cptr)
{
  setup_engineID(NULL, cptr);
  DEBUGMSGTL(("snmpv3","initialized engineID with: %s\n",cptr));
}

void
version_conf(const char *word, char *cptr)
{
  if (strcmp(cptr,"1") == 0) {
    ds_set_int(DS_LIBRARY_ID, DS_LIB_SNMPVERSION, SNMP_VERSION_1);
  } else if (strcasecmp(cptr,"2c") == 0) {
    ds_set_int(DS_LIBRARY_ID, DS_LIB_SNMPVERSION, SNMP_VERSION_2c);
  } else if (strcmp(cptr,"3") == 0) {
    ds_set_int(DS_LIBRARY_ID, DS_LIB_SNMPVERSION, SNMP_VERSION_3);
  } else {
    config_perror("Unknown version specification");
    return;
  }
  DEBUGMSGTL(("snmpv3","set default version to %d\n",
              ds_get_int(DS_LIBRARY_ID, DS_LIB_SNMPVERSION)));
}

/* engineID_old_conf(const char *, char *):

   Reads a octet string encoded engineID into the oldEngineID and
   oldEngineIDLen pointers.
*/
void
oldengineID_conf(const char *word, char *cptr)
{
  read_config_read_octet_string(cptr, &oldEngineID, &oldEngineIDLength);
}


/*******************************************************************-o-******
 * init_snmpv3
 *
 * Parameters:
 *	*type	Label for the config file "type" used by calling entity.
 *      
 * Set time and engineID.
 * Set parsing functions for config file tokens.
 * Initialize SNMP Crypto API (SCAPI).
 */
void
init_snmpv3(const char *type) {

  gettimeofday(&snmpv3starttime, NULL);

  if (!type) type = "__snmpapp__";

  /* we need to be called back later */
  snmp_register_callback(SNMP_CALLBACK_LIBRARY, SNMP_CALLBACK_POST_READ_CONFIG,
                         init_snmpv3_post_config, NULL);
  snmp_register_callback(SNMP_CALLBACK_LIBRARY,
                         SNMP_CALLBACK_POST_PREMIB_READ_CONFIG,
                         init_snmpv3_post_premib_config, NULL);
  /* we need to be called back later */
  snmp_register_callback(SNMP_CALLBACK_LIBRARY, SNMP_CALLBACK_STORE_DATA,
                         snmpv3_store, (void *) strdup(type));

  /* initialize submodules */
  /*   NOTE: this must be after the callbacks are registered above,
             since they need to be called before the USM callbacks. */
  init_usm();

#if		!defined(USE_INTERNAL_MD5)
  /* doesn't belong here at all */
  sc_init();
#endif		/* !USE_INTERNAL_MD5 */

  /* register all our configuration handlers (ack, there's a lot) */

  /* handle engineID setup before everything else which may depend on it */
  register_premib_handler(type,"engineID", engineID_conf, NULL, "string");
  register_premib_handler(type,"oldEngineID", oldengineID_conf, NULL, NULL);
  register_premib_handler(type,"engineIDType", engineIDType_conf, NULL,"num");
  register_premib_handler(type,"engineIDNic", engineIDNic_conf, NULL,"string");
  register_config_handler(type,"engineBoots", engineBoots_conf, NULL, NULL);

  /* default store config entries */
  ds_register_config(ASN_OCTET_STR, "snmp", "defSecurityName", DS_LIBRARY_ID,
                     DS_LIB_SECNAME);
  ds_register_config(ASN_OCTET_STR, "snmp", "defContext", DS_LIBRARY_ID,
                     DS_LIB_CONTEXT);
  ds_register_config(ASN_OCTET_STR, "snmp", "defPassphrase", DS_LIBRARY_ID,
                     DS_LIB_PASSPHRASE);
  ds_register_config(ASN_OCTET_STR, "snmp", "defAuthPassphrase", DS_LIBRARY_ID,
                     DS_LIB_AUTHPASSPHRASE);
  ds_register_config(ASN_OCTET_STR, "snmp", "defPrivPassphrase", DS_LIBRARY_ID,
                     DS_LIB_PRIVPASSPHRASE);
  register_config_handler("snmp","defVersion", version_conf, NULL, "1|2c|3");

  register_config_handler("snmp","defAuthType", snmpv3_authtype_conf, NULL,
                          "MD5|SHA");
  register_config_handler("snmp","defPrivType", snmpv3_privtype_conf, NULL,
                          "DES (currently the only possible value)");
  register_config_handler("snmp","defSecurityLevel", snmpv3_secLevel_conf,
                          NULL, "noAuthNoPriv|authNoPriv|authPriv");
  register_config_handler(type,"userSetAuthPass", usm_set_password, NULL,
                          NULL);
  register_config_handler(type,"userSetPrivPass", usm_set_password, NULL,
                          NULL);
  register_config_handler(type,"userSetAuthKey", usm_set_password, NULL,
                          NULL);
  register_config_handler(type,"userSetPrivKey", usm_set_password, NULL,
                          NULL);
  register_config_handler(type,"userSetAuthLocalKey", usm_set_password, NULL,
                          NULL);
  register_config_handler(type,"userSetPrivLocalKey", usm_set_password, NULL,
                          NULL);
}

/*
 * initializations for SNMPv3 to be called after the configuration files
 * have been read.
 */

int
init_snmpv3_post_config(int majorid, int minorid, void *serverarg,
                        void *clientarg) {

  size_t engineIDLen;
  u_char *c_engineID;

  c_engineID = snmpv3_generate_engineID(&engineIDLen);

  if ( engineIDLen == 0 ) {
    /* Somethine went wrong - help! */
    return SNMPERR_GENERR;
  }

  /* if our engineID has changed at all, the boots record must be set to 1 */
  if (engineIDLen != (int)oldEngineIDLength ||
      oldEngineID == NULL || c_engineID == NULL ||
      memcmp(oldEngineID, c_engineID, engineIDLen) != 0) {
    engineBoots = 1;
  }

  /* set our local engineTime in the LCD timing cache */
  set_enginetime(c_engineID, engineIDLen, 
                 snmpv3_local_snmpEngineBoots(), 
                 snmpv3_local_snmpEngineTime(),
                 TRUE);

  free(c_engineID);
  return SNMPERR_SUCCESS;
}

int
init_snmpv3_post_premib_config(int majorid, int minorid, void *serverarg,
                               void *clientarg) {
    if (!engineIDIsSet)
        setup_engineID(NULL, NULL);
    
    return SNMPERR_SUCCESS;
}

/*******************************************************************-o-******
 * store_snmpv3
 *
 * Parameters:
 *	*type
 */
int
snmpv3_store(int majorID, int minorID, void *serverarg, void *clientarg) {
  char line[SNMP_MAXBUF_SMALL];
  u_char c_engineID[SNMP_MAXBUF_SMALL];
  int  engineIDLen;
  const char *type = (const char *) clientarg;

  if (type == NULL)  /* should never happen, since the arg is ours */
    type = "unknown";

  sprintf(line, "engineBoots %ld", engineBoots);
  read_config_store(type, line);

  engineIDLen = snmpv3_get_engineID(c_engineID, SNMP_MAXBUF_SMALL);

  if (engineIDLen) {
    /* store the engineID used for this run */
    sprintf(line, "oldEngineID ");
    read_config_save_octet_string(line+strlen(line), c_engineID,
                                  engineIDLen);
    read_config_store(type, line);
  }
  return SNMPERR_SUCCESS;
}  /* snmpv3_store() */

u_long
snmpv3_local_snmpEngineBoots(void)
{
  return engineBoots;
}


/*******************************************************************-o-******
 * snmpv3_get_engineID
 *
 * Parameters:
 *	*buf
 *	 buflen
 *      
 * Returns:
 *	Length of engineID	On Success
 *	SNMPERR_GENERR		Otherwise.
 *
 *
 * Store engineID in buf; return the length.
 *
 */
size_t
snmpv3_get_engineID(u_char *buf, size_t buflen)
{
  /*
   * Sanity check.
   */
  if ( !buf || (buflen < engineIDLength) ) {
    return 0;
  }

  memcpy(buf,engineID,engineIDLength);
  return engineIDLength;

}  /* end snmpv3_get_engineID() */

/*******************************************************************-o-******
 * snmpv3_clone_engineID
 *
 * Parameters:
 *	**dest
 *       *dest_len
 *       src
 *	 srclen
 *      
 * Returns:
 *	Length of engineID	On Success
 *	0		        Otherwise.
 *
 *
 * Clones engineID, creates memory
 *
 */
int
snmpv3_clone_engineID(u_char **dest, size_t* destlen, u_char*src, size_t srclen)
{
  if ( !dest || !destlen ) return 0;

  *dest = NULL; *destlen = 0;

  if (srclen && src) {
    *dest = (u_char*)malloc(srclen);
    if (*dest == NULL) return 0;
    memmove(*dest, src, srclen);
    *destlen = srclen;
  }
  return *destlen;
}  /* end snmpv3_clone_engineID() */


/*******************************************************************-o-******
 * snmpv3_generate_engineID
 *
 * Parameters:
 *	*length
 *      
 * Returns:
 *	Pointer to copy of engineID	On Success.
 *	NULL				If malloc() or snmpv3_get_engineID()
 *						fail.
 *
 * Generates a malloced copy of our engineID.
 *
 * 'length' is set to the length of engineID  -OR-  < 0 on failure.
 */
u_char *
snmpv3_generate_engineID(size_t *length)
{
  u_char *newID;
  newID = (u_char *) malloc(engineIDLength);

  if (newID) {
    *length = snmpv3_get_engineID(newID, engineIDLength);
  }

  if (*length == 0) {
    SNMP_FREE(newID);
    newID = NULL;
  }

  return newID;

}  /* end snmpv3_generate_engineID() */

/* snmpv3_local_snmpEngineTime(): return the number of seconds since the
   snmpv3 engine last incremented engine_boots */
u_long
snmpv3_local_snmpEngineTime(void)
{
  struct timeval now;

  gettimeofday(&now, NULL);
  return calculate_time_diff(&now, &snmpv3starttime)/100;
}


/* Code only for Linux systems */
#if defined(IFHWADDRLEN) && defined(SIOCGIFHWADDR)
static int getHwAddress(
	const char * networkDevice, /* e.g. "eth0", "eth1" */
	char * addressOut)	    /* return address. Len=IFHWADDRLEN */
/*  getHwAddress(...)
 *
 *  This function will return a Network Interfaces Card's Hardware
 *  address (aka MAC address).
 *
 *  Input Parameter(s):
 *	networkDevice - a null terminated string with the name of a network
 *			device.  Examples: eth0, eth1, etc...
 *
 *  Output Parameter(s):
 *	addressOut -	This is the binary value of the hardware address.
 *			This value is NOT converted into a hexadecimal string.
 *			The caller must pre-allocate for a return value of
 *			length IFHWADDRLEN
 *
 *  Return value:   This function will return zero (0) for success.  If
 *		    an error occurred the function will return -1.
 *
 *  Caveats:	This has only been tested on Ethernet networking cards.
 */
{
    int sock;		    /* our socket */
    struct ifreq request;   /* struct which will have HW address */

    if ( (NULL == networkDevice) || (NULL == addressOut) )
    {
	    return -1;
    }
    /* In order to find out the hardware (MAC) address of our system under
     * Linux we must do the following:
     * 1.  Create a socket
     * 2.  Do an ioctl(...) call with the SIOCGIFHWADDRLEN operation.
     */
    sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock < 0)
    {
	return -1;
    }
    /* erase the request block */
    memset(&request,0,sizeof(request));
    /* copy the name of the net device we want to find the HW address for */
    strncpy(request.ifr_name, networkDevice,IFNAMSIZ-1);
    /* Get the HW address */
    if (ioctl(sock, SIOCGIFHWADDR, &request))
    {
	close(sock);
	return -1;
    }
    close(sock);
    memcpy(addressOut, request.ifr_hwaddr.sa_data, IFHWADDRLEN);
    return 0;
}
#endif

#ifdef SNMP_TESTING_CODE
/* snmpv3_set_engineBootsAndTime(): this function does not exist.  Go away. */
/*   It certainly should never be used, unless in a testing scenero,
     which is why it was created */
void
snmpv3_set_engineBootsAndTime(int boots, int ttime) {
  engineBoots = boots;
  gettimeofday(&snmpv3starttime, NULL);
  snmpv3starttime.tv_sec -= ttime;
}
#endif
