git.distorted.org.uk Git - u/mdw/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
  36 #include "key-data.h"
  37
  38 /*----- Data structures ---------------------------------------------------*/
  39
  40 typedef struct key_flags {
  41   unsigned f;
  42   unsigned m;
  43 } key_flags;
  44
  45 /*----- Flags table -------------------------------------------------------*/
  46
  47 typedef struct flagent {
  48   const char *name;
  49   unsigned f;
  50   unsigned m;
  51 } flagent;
  52
  53 static const flagent flagtab[] = {
  54
  55   /* --- Encoding types --- */
  56
  57   { "binary",           KENC_BINARY,    KF_ENCMASK },
  58   { "integer",          KENC_MP,        KF_ENCMASK },
  59   { "struct",           KENC_STRUCT,    KF_ENCMASK },
  60   { "encrypt",          KENC_ENCRYPT,   KF_ENCMASK },
  61   { "string",           KENC_STRING,    KF_ENCMASK },
  62   { "ec",               KENC_EC,        KF_ENCMASK },
  63
  64   /* --- Classes of keys --- */
  65
  66   { "shared",           KCAT_SHARE,     KF_CATMASK },
  67   { "public",           KCAT_PUB,       KF_CATMASK },
  68   { "private",          KCAT_PRIV,      KF_CATMASK },
  69   { "symmetric",        KCAT_SYMM,      KF_CATMASK },
  70   { "secret",           0,              KF_NONSECRET },
  71   { "-secret",          KF_NONSECRET,   KF_NONSECRET },
  72
  73   /* --- Other flags --- */
  74
  75   { "burn",             KF_BURN,        KF_BURN },
  76   { "-burn",            0,              KF_BURN },
  77
  78   /* --- End marker --- */
  79
  80   { 0,                  0,              0 }
  81 };
  82
  83 /*----- Main code ---------------------------------------------------------*/
  84
  85 /* --- @key_readflags@ --- *
  86  *
  87  * Arguments:   @const char *p@ = pointer to string to read
  88  *              @char **pp@ = where to store the end pointer
  89  *              @unsigned *ff@ = where to store the flags
  90  *              @unsigned *mm@ = where to store the mask
  91  *
  92  * Returns:     Zero if all went well, nonzero if there was an error.
  93  *
  94  * Use:         Reads a flag string.
  95  */
  96
  97 int key_readflags(const char *p, char **pp, unsigned *ff, unsigned *mm)
  98 {
  99   unsigned f = 0, m = 0;
 100
 101   for (;;) {
 102     size_t sz = strcspn(p, ",:");
 103     const flagent *e, *ee = 0;
 104
 105     /* --- Look up the string in the flags table --- */
 106
 107     if (sz == 4 && strncmp(p, "none", 4) == 0)
 108       goto next;
 109     for (e = flagtab; e->name; e++) {
 110       if (strncmp(e->name, p, sz) == 0) {
 111         if (e->name[sz] == 0) {
 112           ee = e;
 113           break;
 114         } else if (ee)
 115           return (KERR_BADFLAGS);
 116         else
 117           ee = e;
 118       }
 119     }
 120     if (!ee)
 121       return (KERR_BADFLAGS);
 122
 123     /* --- Adjust the flag words --- *
 124      *
 125      * Ensure that the flags set are disjoint.
 126      */
 127
 128     if (m & ee->m)
 129       return (KERR_BADFLAGS);
 130     m |= ee->m;
 131     f |= ee->f;
 132   next:
 133     p += sz;
 134     if (*p == 0 || *p == ':')
 135       break;
 136     p++;
 137   }
 138
 139   /* --- Report the results --- */
 140
 141   if (ff) *ff = f;
 142   if (mm) *mm = m;
 143   if (pp) *pp = (char *)p;
 144   return (0);
 145 }
 146
 147 /* --- @key_writeflags@ --- *
 148  *
 149  * Arguments:   @unsigned f@ = flags to write
 150  *              @dstr *d@ = pointer to destination string
 151  *
 152  * Returns:     ---
 153  *
 154  * Use:         Emits a flags word as a string representation.
 155  */
 156
 157 void key_writeflags(unsigned f, dstr *d)
 158 {
 159   int del = 0;
 160   const flagent *e;
 161   unsigned m = 0;
 162
 163   for (e = flagtab; e->name; e++) {
 164     if (m & e->m || e->name[0] == '-' || (f & e->m) != e->f)
 165       continue;
 166     if (del)
 167       DPUTC(d, ',');
 168     DPUTS(d, e->name);
 169     m |= e->m;
 170     del = 1;
 171   }
 172 }
 173
 174 /* --- @key_match@ --- *
 175  *
 176  * Arguments:   @key_data *k@ = pointer to key data block
 177  *              @const key_filter *kf@ = pointer to filter block
 178  *
 179  * Returns:     Nonzero if the key matches the filter.
 180  *
 181  * Use:         Checks whether a key matches a filter.
 182  */
 183
 184 int key_match(key_data *k, const key_filter *kf)
 185 {
 186   key_subkeyiter i;
 187   const char *tag;
 188   key_data *kd;
 189
 190   if (!kf)
 191     return (1);
 192   if ((k->e & KF_ENCMASK) != KENC_STRUCT)
 193     return ((k->e & kf->m) == kf->f);
 194
 195   for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &kd); ) {
 196     if (key_match(kd, kf))
 197       return (1);
 198   }
 199   return (0);
 200 }
 201
 202 /*----- That's all, folks -------------------------------------------------*/