mdw@git.distorted.org.uk Git - catacomb/blob - key/key-flags.c

   1 /* -*-c-*-
   2  *
   3  * Reading and writing key flag strings
   4  *
   5  * (c) 1999 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include <stdlib.h>
  31 #include <string.h>
  32
  33 #include <mLib/bits.h>
  34 #include <mLib/dstr.h>
  35 #include <mLib/macros.h>
  36
  37 #include "key-data.h"
  38
  39 /*----- Data structures ---------------------------------------------------*/
  40
  41 typedef struct key_flags {
  42   unsigned f;
  43   unsigned m;
  44 } key_flags;
  45
  46 /*----- Flags table -------------------------------------------------------*/
  47
  48 typedef struct flagent {
  49   const char *name;
  50   unsigned f;
  51   unsigned m;
  52 } flagent;
  53
  54 static const flagent flagtab[] = {
  55
  56   /* --- Encoding types --- */
  57
  58   { "binary",           KENC_BINARY,    KF_ENCMASK },
  59   { "integer",          KENC_MP,        KF_ENCMASK },
  60   { "struct",           KENC_STRUCT,    KF_ENCMASK },
  61   { "encrypt",          KENC_ENCRYPT,   KF_ENCMASK },
  62   { "string",           KENC_STRING,    KF_ENCMASK },
  63   { "ec",               KENC_EC,        KF_ENCMASK },
  64
  65   /* --- Classes of keys --- */
  66
  67   { "shared",           KCAT_SHARE,     KF_CATMASK },
  68   { "public",           KCAT_PUB,       KF_CATMASK },
  69   { "private",          KCAT_PRIV,      KF_CATMASK },
  70   { "symmetric",        KCAT_SYMM,      KF_CATMASK },
  71   { "secret",           0,              KF_NONSECRET },
  72   { "-secret",          KF_NONSECRET,   KF_NONSECRET },
  73
  74   /* --- Other flags --- */
  75
  76   { "burn",             KF_BURN,        KF_BURN },
  77   { "-burn",            0,              KF_BURN },
  78
  79   /* --- End marker --- */
  80
  81   { 0,                  0,              0 }
  82 };
  83
  84 /*----- Main code ---------------------------------------------------------*/
  85
  86 /* --- @key_readflags@ --- *
  87  *
  88  * Arguments:   @const char *p@ = pointer to string to read
  89  *              @char **pp@ = where to store the end pointer
  90  *              @unsigned *ff@ = where to store the flags
  91  *              @unsigned *mm@ = where to store the mask
  92  *
  93  * Returns:     Zero if all went well, nonzero if there was an error.
  94  *
  95  * Use:         Reads a flag string.
  96  */
  97
  98 int key_readflags(const char *p, char **pp, unsigned *ff, unsigned *mm)
  99 {
 100   unsigned f = 0, m = 0;
 101
 102   for (;;) {
 103     size_t sz = strcspn(p, ",:");
 104     const flagent *e, *ee = 0;
 105
 106     /* --- Look up the string in the flags table --- */
 107
 108     if (sz == 4 && STRNCMP(p, ==, "none", 4))
 109       goto next;
 110     for (e = flagtab; e->name; e++) {
 111       if (STRNCMP(e->name, ==, p, sz)) {
 112         if (e->name[sz] == 0) {
 113           ee = e;
 114           break;
 115         } else if (ee)
 116           return (KERR_BADFLAGS);
 117         else
 118           ee = e;
 119       }
 120     }
 121     if (!ee)
 122       return (KERR_BADFLAGS);
 123
 124     /* --- Adjust the flag words --- *
 125      *
 126      * Ensure that the flags set are disjoint.
 127      */
 128
 129     if (m & ee->m)
 130       return (KERR_BADFLAGS);
 131     m |= ee->m;
 132     f |= ee->f;
 133   next:
 134     p += sz;
 135     if (*p == 0 || *p == ':')
 136       break;
 137     p++;
 138   }
 139
 140   /* --- Report the results --- */
 141
 142   if (ff) *ff = f;
 143   if (mm) *mm = m;
 144   if (pp) *pp = (char *)p;
 145   return (0);
 146 }
 147
 148 /* --- @key_writeflags@ --- *
 149  *
 150  * Arguments:   @unsigned f@ = flags to write
 151  *              @dstr *d@ = pointer to destination string
 152  *
 153  * Returns:     ---
 154  *
 155  * Use:         Emits a flags word as a string representation.
 156  */
 157
 158 void key_writeflags(unsigned f, dstr *d)
 159 {
 160   int del = 0;
 161   const flagent *e;
 162   unsigned m = 0;
 163
 164   for (e = flagtab; e->name; e++) {
 165     if (m & e->m || e->name[0] == '-' || (f & e->m) != e->f)
 166       continue;
 167     if (del)
 168       DPUTC(d, ',');
 169     DPUTS(d, e->name);
 170     m |= e->m;
 171     del = 1;
 172   }
 173 }
 174
 175 /* --- @key_match@ --- *
 176  *
 177  * Arguments:   @key_data *k@ = pointer to key data block
 178  *              @const key_filter *kf@ = pointer to filter block
 179  *
 180  * Returns:     Nonzero if the key matches the filter.
 181  *
 182  * Use:         Checks whether a key matches a filter.
 183  */
 184
 185 int key_match(key_data *k, const key_filter *kf)
 186 {
 187   key_subkeyiter i;
 188   const char *tag;
 189   key_data *kd;
 190
 191   if (!kf)
 192     return (1);
 193   if ((k->e & KF_ENCMASK) != KENC_STRUCT)
 194     return ((k->e & kf->m) == kf->f);
 195
 196   for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &kd); ) {
 197     if (key_match(kd, kf))
 198       return (1);
 199   }
 200   return (0);
 201 }
 202
 203 /*----- That's all, folks -------------------------------------------------*/