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glibc  2.9
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svcauth_des.c File Reference
#include <limits.h>
#include <string.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <rpc/rpc.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/auth_des.h>
#include <rpc/svc_auth.h>
#include <rpc/svc.h>
#include <rpc/des_crypt.h>

Go to the source code of this file.

Classes

struct  cache_entry
struct  bsdcred

Defines

#define debug(msg)   /*printf("svcauth_des: %s\n", msg) */
#define USEC_PER_SEC   ((uint32_t) 1000000L)
#define BEFORE(t1, t2)   timercmp(t1, t2, <)
#define AUTHDES_CACHESZ   64
#define UNKNOWN   -2 /* grouplen, if cached cred is unknown user */
#define INVALID   -1 /* grouplen, if cache entry is invalid */

Functions

static void cache_init (void)
enum auth_stat _svcauth_des (register struct svc_req *rqst, register struct rpc_msg *msg)
static short cache_victim (void)
static void internal_function cache_ref (register uint32_t sid)
static short internal_function cache_spot (register des_block *key, char *name, struct rpc_timeval *timestamp)
int authdes_getucred (const struct authdes_cred *adc, uid_t *uid, gid_t *gid, short *grouplen, gid_t *groups)
static void internal_function invalidate (char *cred)

Variables

static struct cache_entryauthdes_cache
static intauthdes_lru
 svcauthdes_stats

Class Documentation

struct cache_entry

Definition at line 37 of file cache.c.

Collaboration diagram for cache_entry:
Class Members
int bits_hwcap
int flags
uint64_t hwcap
des_block key
char * lib
char * localcred
struct cache_entry * next
unsigned int osversion
char * path
char * rname
u_int window
struct bsdcred

Definition at line 485 of file svcauth_des.c.

Class Members
gid_t gid
int grouplen
int grouplen_max
gid_t groups
uid_t uid

Define Documentation

#define AUTHDES_CACHESZ   64

Definition at line 66 of file svcauth_des.c.

#define BEFORE (   t1,
  t2 
)    timercmp(t1, t2, <)

Definition at line 61 of file svcauth_des.c.

#define debug (   msg)    /*printf("svcauth_des: %s\n", msg) */

Definition at line 58 of file svcauth_des.c.

#define INVALID   -1 /* grouplen, if cache entry is invalid */

Definition at line 483 of file svcauth_des.c.

#define UNKNOWN   -2 /* grouplen, if cached cred is unknown user */

Definition at line 482 of file svcauth_des.c.

#define USEC_PER_SEC   ((uint32_t) 1000000L)

Definition at line 60 of file svcauth_des.c.


Function Documentation

enum auth_stat _svcauth_des ( register struct svc_req rqst,
register struct rpc_msg msg 
)

Definition at line 107 of file svcauth_des.c.

{
  register uint32_t *ixdr;
  des_block cryptbuf[2];
  register struct authdes_cred *cred;
  struct authdes_verf verf;
  int status;
  register struct cache_entry *entry;
  uint32_t sid = 0;
  des_block *sessionkey;
  des_block ivec;
  u_int window;
  struct rpc_timeval timestamp;
  uint32_t namelen;
  struct area
    {
      struct authdes_cred area_cred;
      char area_netname[MAXNETNAMELEN + 1];
    }
   *area;

  if (authdes_cache == NULL)
    cache_init ();
  if (authdes_cache == NULL) /* No free memory */
    return AUTH_FAILED;

  area = (struct area *) rqst->rq_clntcred;
  cred = (struct authdes_cred *) &area->area_cred;

  /*
   * Get the credential
   */
  if (msg->rm_call.cb_cred.oa_length <= 0 ||
      msg->rm_call.cb_cred.oa_length > MAX_AUTH_BYTES)
    return AUTH_BADCRED;

  ixdr = (uint32_t *) msg->rm_call.cb_cred.oa_base;
  cred->adc_namekind = IXDR_GET_ENUM (ixdr, enum authdes_namekind);
  switch (cred->adc_namekind)
    {
    case ADN_FULLNAME:
      namelen = IXDR_GET_U_INT32 (ixdr);
      if (namelen > MAXNETNAMELEN)
       {
         return AUTH_BADCRED;
       }
      cred->adc_fullname.name = area->area_netname;
      memcpy (cred->adc_fullname.name, (char *) ixdr, namelen);
      cred->adc_fullname.name[namelen] = 0;
      ixdr += (RNDUP (namelen) / BYTES_PER_XDR_UNIT);
      cred->adc_fullname.key.key.high = *ixdr++;
      cred->adc_fullname.key.key.low = *ixdr++;
      cred->adc_fullname.window = *ixdr++;
      break;
    case ADN_NICKNAME:
      cred->adc_nickname = *ixdr++;
      break;
    default:
      return AUTH_BADCRED;
    }

  /*
   * Get the verifier
   */
  if (msg->rm_call.cb_verf.oa_length <= 0 ||
      msg->rm_call.cb_verf.oa_length > MAX_AUTH_BYTES)
    return AUTH_BADCRED;

  ixdr = (uint32_t *) msg->rm_call.cb_verf.oa_base;
  verf.adv_xtimestamp.key.high = *ixdr++;
  verf.adv_xtimestamp.key.low = *ixdr++;
  verf.adv_int_u = *ixdr++;

  /*
   * Get the conversation key
   */
  if (cred->adc_namekind == ADN_FULLNAME)
    {
      netobj pkey;
      char pkey_data[1024];

      sessionkey = &cred->adc_fullname.key;
      if (!getpublickey (cred->adc_fullname.name, pkey_data))
       {
         debug("getpublickey");
         return AUTH_BADCRED;
       }
      pkey.n_bytes = pkey_data;
      pkey.n_len = strlen (pkey_data) + 1;
      if (key_decryptsession_pk (cred->adc_fullname.name, &pkey,
                             sessionkey) < 0)
       {
         debug ("decryptsessionkey");
         return AUTH_BADCRED;      /* key not found */
       }
    }
  else
    {                       /* ADN_NICKNAME */
      if (cred->adc_nickname >= AUTHDES_CACHESZ)
       {
         debug ("bad nickname");
         return AUTH_BADCRED;      /* garbled credential */
       }
      else
       sid = cred->adc_nickname;

      /* XXX This could be wrong, but else we have a
        security problem */
      if (authdes_cache[sid].rname == NULL)
       return AUTH_BADCRED;
      sessionkey = &authdes_cache[sid].key;
    }


  /*
   * Decrypt the timestamp
   */
  cryptbuf[0] = verf.adv_xtimestamp;
  if (cred->adc_namekind == ADN_FULLNAME)
    {
      cryptbuf[1].key.high = cred->adc_fullname.window;
      cryptbuf[1].key.low = verf.adv_winverf;
      ivec.key.high = ivec.key.low = 0;
      status = cbc_crypt ((char *) sessionkey, (char *) cryptbuf,
                       2 * sizeof (des_block), DES_DECRYPT | DES_HW,
                       (char *) &ivec);
    }
  else
    status = ecb_crypt ((char *) sessionkey, (char *) cryptbuf,
                     sizeof (des_block), DES_DECRYPT | DES_HW);

  if (DES_FAILED (status))
    {
      debug ("decryption failure");
      return AUTH_FAILED;   /* system error */
    }

  /*
   * XDR the decrypted timestamp
   */
  ixdr = (uint32_t *) cryptbuf;
  timestamp.tv_sec = IXDR_GET_INT32 (ixdr);
  timestamp.tv_usec = IXDR_GET_INT32 (ixdr);

  /*
   * Check for valid credentials and verifiers.
   * They could be invalid because the key was flushed
   * out of the cache, and so a new session should begin.
   * Be sure and send AUTH_REJECTED{CRED, VERF} if this is the case.
   */
  {
    struct timeval current;
    int nick;
    u_int winverf;

    if (cred->adc_namekind == ADN_FULLNAME)
      {
       short tmp_spot;

       window = IXDR_GET_U_INT32 (ixdr);
       winverf = IXDR_GET_U_INT32 (ixdr);
       if (winverf != window - 1)
         {
           debug ("window verifier mismatch");
           return AUTH_BADCRED;    /* garbled credential */
         }
       tmp_spot = cache_spot (sessionkey, cred->adc_fullname.name,
                            &timestamp);
       if (tmp_spot < 0 || tmp_spot > AUTHDES_CACHESZ)
         {
           debug ("replayed credential");
           return AUTH_REJECTEDCRED;             /* replay */
         }
       sid = tmp_spot;
       nick = 0;
      }
    else
      {                            /* ADN_NICKNAME */
       window = authdes_cache[sid].window;
       nick = 1;
      }

    if (timestamp.tv_usec >= USEC_PER_SEC)
      {
       debug ("invalid usecs");
       /* cached out (bad key), or garbled verifier */
       return nick ? AUTH_REJECTEDVERF : AUTH_BADVERF;
      }
    if (nick && BEFORE (&timestamp, &authdes_cache[sid].laststamp))
      {
       debug ("timestamp before last seen");
       return AUTH_REJECTEDVERF;   /* replay */
      }
    __gettimeofday (&current, (struct timezone *) NULL);
    current.tv_sec -= window;      /* allow for expiration */
    if (!BEFORE (&current, &timestamp))
      {
       debug ("timestamp expired");
       /* replay, or garbled credential */
       return nick ? AUTH_REJECTEDVERF : AUTH_BADCRED;
      }
  }

  /*
   * Set up the reply verifier
   */
  verf.adv_nickname = sid;

  /*
   * xdr the timestamp before encrypting
   */
  ixdr = (uint32_t *) cryptbuf;
  IXDR_PUT_INT32 (ixdr, timestamp.tv_sec - 1);
  IXDR_PUT_INT32 (ixdr, timestamp.tv_usec);

  /*
   * encrypt the timestamp
   */
  status = ecb_crypt ((char *) sessionkey, (char *) cryptbuf,
                    sizeof (des_block), DES_ENCRYPT | DES_HW);
  if (DES_FAILED (status))
    {
      debug ("encryption failure");
      return AUTH_FAILED;   /* system error */
    }
  verf.adv_xtimestamp = cryptbuf[0];

  /*
   * Serialize the reply verifier, and update rqst
   */
  ixdr = (uint32_t *) msg->rm_call.cb_verf.oa_base;
  *ixdr++ = verf.adv_xtimestamp.key.high;
  *ixdr++ = verf.adv_xtimestamp.key.low;
  *ixdr++ = verf.adv_int_u;

  rqst->rq_xprt->xp_verf.oa_flavor = AUTH_DES;
  rqst->rq_xprt->xp_verf.oa_base = msg->rm_call.cb_verf.oa_base;
  rqst->rq_xprt->xp_verf.oa_length =
    (char *) ixdr - msg->rm_call.cb_verf.oa_base;

  /*
   * We succeeded, commit the data to the cache now and
   * finish cooking the credential.
   */
  entry = &authdes_cache[sid];
  entry->laststamp = timestamp;
  cache_ref (sid);
  if (cred->adc_namekind == ADN_FULLNAME)
    {
      size_t full_len;

      cred->adc_fullname.window = window;
      cred->adc_nickname = sid;    /* save nickname */
      if (entry->rname != NULL)
       mem_free (entry->rname, strlen (entry->rname) + 1);
      full_len = strlen (cred->adc_fullname.name) + 1;
      entry->rname = mem_alloc ((u_int) full_len);
      if (entry->rname != NULL)
       memcpy (entry->rname, cred->adc_fullname.name, full_len);
      else
       {
         debug ("out of memory");
         return AUTH_FAILED; /* out of memory is bad */
       }
      entry->key = *sessionkey;
      entry->window = window;
      invalidate (entry->localcred);      /* mark any cached cred invalid */
    }
  else
    {                       /* ADN_NICKNAME */
      /*
       * nicknames are cooked into fullnames
       */
      cred->adc_namekind = ADN_FULLNAME;
      cred->adc_fullname.name = entry->rname;
      cred->adc_fullname.key = entry->key;
      cred->adc_fullname.window = entry->window;
    }
  return AUTH_OK;           /* we made it! */
}

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int authdes_getucred ( const struct authdes_cred adc,
uid_t uid,
gid_t gid,
short *  grouplen,
gid_t groups 
)

Definition at line 501 of file svcauth_des.c.

{
  unsigned sid;
  register int i;
  uid_t i_uid;
  gid_t i_gid;
  int i_grouplen;
  struct bsdcred *cred;

  sid = adc->adc_nickname;
  if (sid >= AUTHDES_CACHESZ)
    {
      debug ("invalid nickname");
      return 0;
    }
  cred = (struct bsdcred *) authdes_cache[sid].localcred;
  if (cred == NULL || cred->grouplen == INVALID)
    {
      /*
       * not in cache: lookup
       */
      if (!netname2user (adc->adc_fullname.name, &i_uid, &i_gid,
                      &i_grouplen, groups))
       {
         debug ("unknown netname");
         if (cred != NULL)
           cred->grouplen = UNKNOWN;      /* mark as lookup up, but not found */
         return 0;
       }

      if (cred != NULL && cred->grouplen_max < i_grouplen)
       {
         /* We already have an allocated data structure.  But it is
            too small.  */
         free (cred);
         authdes_cache[sid].localcred = NULL;
         cred = NULL;
       }

      if (cred == NULL)
       {
         /* We should allocate room for at least NGROUPS groups.  */
         int ngroups_max = MAX (i_grouplen, NGROUPS);

         cred = (struct bsdcred *) mem_alloc (sizeof (struct bsdcred)
                                          + ngroups_max * sizeof (gid_t));
         if (cred == NULL)
           return 0;

         authdes_cache[sid].localcred = (char *) cred;
         cred->grouplen = INVALID;
         cred->grouplen_max = ngroups_max;
       }

      debug ("missed ucred cache");
      *uid = cred->uid = i_uid;
      *gid = cred->gid = i_gid;
      cred->grouplen = i_grouplen;
      for (i = i_grouplen - 1; i >= 0; --i)
       cred->groups[i] = groups[i];
      /* Make sure no too large values are reported.  */
      *grouplen = MIN (SHRT_MAX, i_grouplen);
      return 1;
    }
  else if (cred->grouplen == UNKNOWN)
    {
      /*
       * Already lookup up, but no match found
       */
      return 0;
    }

  /*
   * cached credentials
   */
  *uid = cred->uid;
  *gid = cred->gid;

  /* Another stupidity in the interface: *grouplen is of type short.
     So we might have to cut the information passed up short.  */
  int grouplen_copy = MIN (SHRT_MAX, cred->grouplen);
  *grouplen = grouplen_copy;
  for (i = grouplen_copy - 1; i >= 0; --i)
    groups[i] = cred->groups[i];
  return 1;
}

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static void internal_function cache_init ( void  ) [static]

Definition at line 83 of file svcauth_des.c.

  {
    u_long ncachehits;             /* times cache hit, and is not replay */
    u_long ncachereplays;   /* times cache hit, and is replay */
    u_long ncachemisses;    /* times cache missed */
  }

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static void internal_function cache_ref ( register uint32_t  sid) [static]

Definition at line 426 of file svcauth_des.c.

{
  register int i;
  register int curr;
  register int prev;

  prev = authdes_lru[0];
  authdes_lru[0] = sid;
  for (i = 1; prev != sid; ++i)
    {
      curr = authdes_lru[i];
      authdes_lru[i] = prev;
      prev = curr;
    }
}

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static short internal_function cache_spot ( register des_block key,
char *  name,
struct rpc_timeval timestamp 
) [static]

Definition at line 449 of file svcauth_des.c.

{
  register struct cache_entry *cp;
  register int i;
  register uint32_t hi;

  hi = key->key.high;
  for (cp = authdes_cache, i = 0; i < AUTHDES_CACHESZ; ++i, ++cp)
    {
      if (cp->key.key.high == hi &&
         cp->key.key.low == key->key.low &&
         cp->rname != NULL &&
         memcmp (cp->rname, name, strlen (name) + 1) == 0)
       {
         if (BEFORE (timestamp, &cp->laststamp))
           {
             ++svcauthdes_stats.ncachereplays;
             return -1;     /* replay */
           }
         ++svcauthdes_stats.ncachehits;
         return i;          /* refresh */
       }
    }
  ++svcauthdes_stats.ncachemisses;
  return cache_victim ();   /* new credential */
}

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static short cache_victim ( void  ) [static]

Definition at line 416 of file svcauth_des.c.

{
  return authdes_lru[AUTHDES_CACHESZ - 1];
}

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static void internal_function invalidate ( char *  cred) [static]

Definition at line 591 of file svcauth_des.c.

{
  if (cred == NULL)
    return;
  ((struct bsdcred *) cred)->grouplen = INVALID;
}

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Variable Documentation

struct cache_entry* authdes_cache [static]

Definition at line 79 of file svcauth_des.c.

int* authdes_lru [static]

Definition at line 80 of file svcauth_des.c.

Definition at line 101 of file svcauth_des.c.