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

   1 /* -*-c-*-
   2  *
   3  * $Id: key-flags.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * Reading and writing key flag strings
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Header files ------------------------------------------------------*/
  31
  32 #include <stdlib.h>
  33 #include <string.h>
  34
  35 #include <mLib/bits.h>
  36 #include <mLib/dstr.h>
  37
  38 #include "key.h"
  39
  40 /*----- Data structures ---------------------------------------------------*/
  41
  42 typedef struct key_flags {
  43   unsigned f;
  44   unsigned m;
  45 } key_flags;
  46
  47 /*----- Flags table -------------------------------------------------------*/
  48
  49 typedef struct flagent {
  50   const char *name;
  51   unsigned f;
  52   unsigned m;
  53 } flagent;
  54
  55 static const flagent flagtab[] = {
  56
  57   /* --- Encoding types --- */
  58
  59   { "binary",           KENC_BINARY,    KF_ENCMASK },
  60   { "integer",          KENC_MP,        KF_ENCMASK },
  61   { "struct",           KENC_STRUCT,    KF_ENCMASK },
  62   { "encrypt",          KENC_ENCRYPT,   KF_ENCMASK },
  63   { "string",           KENC_STRING,    KF_ENCMASK },
  64   { "ec",               KENC_EC,        KF_ENCMASK },
  65
  66   /* --- Classes of keys --- */
  67
  68   { "shared",           KCAT_SHARE,     KF_CATMASK },
  69   { "public",           KCAT_PUB,       KF_CATMASK },
  70   { "private",          KCAT_PRIV,      KF_CATMASK },
  71   { "symmetric",        KCAT_SYMM,      KF_CATMASK },
  72   { "secret",           0,              KF_NONSECRET },
  73   { "-secret",          KF_NONSECRET,   KF_NONSECRET },
  74
  75   /* --- Other flags --- */
  76
  77   { "burn",             KF_BURN,        KF_BURN },
  78   { "-burn",            0,              KF_BURN },
  79
  80   /* --- End marker --- */
  81
  82   { 0,                  0,              0 }
  83 };
  84
  85 /*----- Main code ---------------------------------------------------------*/
  86
  87 /* --- @key_readflags@ --- *
  88  *
  89  * Arguments:   @const char *p@ = pointer to string to read
  90  *              @char **pp@ = where to store the end pointer
  91  *              @unsigned *ff@ = where to store the flags
  92  *              @unsigned *mm@ = where to store the mask
  93  *
  94  * Returns:     Zero if all went well, nonzero if there was an error.
  95  *
  96  * Use:         Reads a flag string.
  97  */
  98
  99 int key_readflags(const char *p, char **pp, unsigned *ff, unsigned *mm)
 100 {
 101   unsigned f = 0, m = 0;
 102
 103   for (;;) {
 104     size_t sz = strcspn(p, ",:");
 105     const flagent *e, *ee = 0;
 106
 107     /* --- Look up the string in the flags table --- */
 108
 109     if (sz == 4 && strncmp(p, "none", 4) == 0)
 110       goto next;
 111     for (e = flagtab; e->name; e++) {
 112       if (strncmp(e->name, p, sz) == 0) {
 113         if (e->name[sz] == 0) {
 114           ee = e;
 115           break;
 116         } else if (ee)
 117           return (KERR_BADFLAGS);
 118         else
 119           ee = e;
 120       }
 121     }
 122     if (!ee)
 123       return (KERR_BADFLAGS);
 124
 125     /* --- Adjust the flag words --- *
 126      *
 127      * Ensure that the flags set are disjoint.
 128      */
 129
 130     if (m & ee->m)
 131       return (KERR_BADFLAGS);
 132     m |= ee->m;
 133     f |= ee->f;
 134   next:
 135     p += sz;
 136     if (*p == 0 || *p == ':')
 137       break;
 138     p++;
 139   }
 140
 141   /* --- Report the results --- */
 142
 143   if (ff) *ff = f;
 144   if (mm) *mm = m;
 145   if (pp) *pp = (char *)p;
 146   return (0);
 147 }
 148
 149 /* --- @key_writeflags@ --- *
 150  *
 151  * Arguments:   @unsigned f@ = flags to write
 152  *              @dstr *d@ = pointer to destination string
 153  *
 154  * Returns:     ---
 155  *
 156  * Use:         Emits a flags word as a string representation.
 157  */
 158
 159 void key_writeflags(unsigned f, dstr *d)
 160 {
 161   int del = 0;
 162   const flagent *e;
 163   unsigned m = 0;
 164
 165   for (e = flagtab; e->name; e++) {
 166     if (m & e->m || e->name[0] == '-' || (f & e->m) != e->f)
 167       continue;
 168     if (del)
 169       DPUTC(d, ',');
 170     DPUTS(d, e->name);
 171     m |= e->m;
 172     del = 1;
 173   }
 174 }
 175
 176 /* --- @key_match@ --- *
 177  *
 178  * Arguments:   @key_data *k@ = pointer to key data block
 179  *              @const key_filter *kf@ = pointer to filter block
 180  *
 181  * Returns:     Nonzero if the key matches the filter.
 182  *
 183  * Use:         Checks whether a key matches a filter.
 184  */
 185
 186 int key_match(key_data *k, const key_filter *kf)
 187 {
 188   sym_iter i;
 189   key_struct *ks;
 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 (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
 197     if (key_match(&ks->k, kf))
 198       return (1);
 199   }
 200   return (0);
 201 }
 202
 203 /*----- That's all, folks -------------------------------------------------*/