| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: key-pack.c,v 1.2 2004/03/28 01:58:47 mdw Exp $ |
| 4 | * |
| 5 | * Packing and unpacking key data |
| 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 | /*----- Revision history --------------------------------------------------* |
| 31 | * |
| 32 | * $Log: key-pack.c,v $ |
| 33 | * Revision 1.2 2004/03/28 01:58:47 mdw |
| 34 | * Generate, store and retreive elliptic curve keys. |
| 35 | * |
| 36 | * Revision 1.1 2000/06/17 10:42:41 mdw |
| 37 | * Packing and unpacking structured keys. |
| 38 | * |
| 39 | */ |
| 40 | |
| 41 | /*----- Header files ------------------------------------------------------*/ |
| 42 | |
| 43 | #include <mLib/dstr.h> |
| 44 | |
| 45 | #include "key.h" |
| 46 | #include "key-data.h" |
| 47 | |
| 48 | /*----- Generic packing and unpacking -------------------------------------*/ |
| 49 | |
| 50 | /* --- @key_pack@ --- * |
| 51 | * |
| 52 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
| 53 | * @key_data *kd@ = pointer to destination key data |
| 54 | * @dstr *d@ = pointer to tag string for the key data |
| 55 | * |
| 56 | * Returns: Error code, or zero. |
| 57 | * |
| 58 | * Use: Packs a key from a data structure. |
| 59 | */ |
| 60 | |
| 61 | int key_pack(key_packdef *kp, key_data *kd, dstr *d) |
| 62 | { |
| 63 | switch (kp->kd.e & KF_ENCMASK) { |
| 64 | |
| 65 | /* --- Binary and integer keys are easy --- */ |
| 66 | |
| 67 | case KENC_BINARY: |
| 68 | kd->u.k = *(key_bin *)kp->p; |
| 69 | return (0); |
| 70 | case KENC_MP: |
| 71 | kd->u.m = *(mp **)kp->p; |
| 72 | return (0); |
| 73 | case KENC_STRING: |
| 74 | kd->u.p = *(char **)kp->p; |
| 75 | return (0); |
| 76 | case KENC_EC: |
| 77 | kd->u.e = *(ec *)kp->p; |
| 78 | return (0); |
| 79 | |
| 80 | /* --- Encrypted keys are a little tricky --- * |
| 81 | * |
| 82 | * This works rather differently to unpacking. |
| 83 | */ |
| 84 | |
| 85 | case KENC_ENCRYPT: { |
| 86 | key_data kkd; |
| 87 | int err = key_pack(kp->p, &kkd, d); |
| 88 | if (!err) { |
| 89 | if (key_plock(d->buf, &kkd, kd)) |
| 90 | err = KERR_BADPASS; |
| 91 | key_destroy(&kkd); |
| 92 | } |
| 93 | return (err); |
| 94 | } |
| 95 | |
| 96 | /* --- Structured keys, as ever, are a nuisance --- */ |
| 97 | |
| 98 | case KENC_STRUCT: { |
| 99 | int err; |
| 100 | key_packstruct *p; |
| 101 | size_t l = d->len; |
| 102 | |
| 103 | key_structure(kd); |
| 104 | DPUTC(d, '.'); |
| 105 | for (p = kp->p; p->name; p++) { |
| 106 | key_data *kkd; |
| 107 | d->len = l + 1; |
| 108 | DPUTS(d, p->name); |
| 109 | kkd = key_structcreate(kd, p->name); |
| 110 | if ((err = key_pack(&p->kp, kkd, d)) != 0) { |
| 111 | key_destroy(kd); |
| 112 | return (err); |
| 113 | } |
| 114 | } |
| 115 | d->len = l; |
| 116 | d->buf[l] = 0; |
| 117 | return (0); |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | return (KERR_BADTYPE); |
| 122 | } |
| 123 | |
| 124 | /* --- @key_unpack@ --- * |
| 125 | * |
| 126 | * Arguments: @key_packdef *kp@ = pointer to packing structure |
| 127 | * @key_data *kd@ = pointer to source key data |
| 128 | * @dstr *d@ = pointer to tag string for the key data |
| 129 | * |
| 130 | * Returns: Error code, or zero. |
| 131 | * |
| 132 | * Use: Unpacks a key into an appropriate data structure. |
| 133 | */ |
| 134 | |
| 135 | int key_unpack(key_packdef *kp, key_data *kd, dstr *d) |
| 136 | { |
| 137 | unsigned e = kp->kd.e & KF_ENCMASK; |
| 138 | int err; |
| 139 | |
| 140 | /* --- Decrypt the encrypted key --- */ |
| 141 | |
| 142 | while ((kd->e & KF_ENCMASK) == KENC_ENCRYPT) { |
| 143 | if (key_punlock(d->buf, kd, &kp->kd)) { |
| 144 | err = KERR_BADPASS; |
| 145 | goto fail; |
| 146 | } |
| 147 | kd = &kp->kd; |
| 148 | kd->e |= KF_TEMP; |
| 149 | } |
| 150 | |
| 151 | /* --- Ensure that the key has the right type --- */ |
| 152 | |
| 153 | if ((kd->e & KF_ENCMASK) != e) { |
| 154 | err = KERR_BADTYPE; |
| 155 | goto fail; |
| 156 | } |
| 157 | |
| 158 | /* --- Unpack the key --- * |
| 159 | * |
| 160 | * Only three possibilities left now. |
| 161 | */ |
| 162 | |
| 163 | switch (e) { |
| 164 | |
| 165 | /* --- Binary and integer keys are easy --- */ |
| 166 | |
| 167 | case KENC_BINARY: |
| 168 | *(key_bin *)kp->p = kd->u.k; |
| 169 | break; |
| 170 | case KENC_MP: |
| 171 | *(mp **)kp->p = kd->u.m; |
| 172 | break; |
| 173 | case KENC_STRING: |
| 174 | *(char **)kp->p = kd->u.p; |
| 175 | break; |
| 176 | case KENC_EC: |
| 177 | *(ec *)kp->p = kd->u.e; |
| 178 | break; |
| 179 | |
| 180 | /* --- Structured keys take a little care --- */ |
| 181 | |
| 182 | case KENC_STRUCT: { |
| 183 | key_packstruct *p, *q; |
| 184 | size_t l = d->len; |
| 185 | |
| 186 | /* --- Iterate over the requested subparts --- */ |
| 187 | |
| 188 | DPUTC(d, '.'); |
| 189 | for (p = kp->p; p->name; p++) { |
| 190 | key_data *kkd; |
| 191 | |
| 192 | /* --- Build the name --- */ |
| 193 | |
| 194 | d->len = l + 1; |
| 195 | DPUTS(d, p->name); |
| 196 | |
| 197 | /* --- Find and unpack the subkey --- */ |
| 198 | |
| 199 | if ((kkd = key_structfind(kd, p->name)) == 0) { |
| 200 | if (!(p->kp.kd.e & KF_OPT)) { |
| 201 | err = KERR_NOTFOUND; |
| 202 | goto tidy; |
| 203 | } |
| 204 | } else if ((err = key_unpack(&p->kp, kkd, d)) != 0) { |
| 205 | p++; |
| 206 | goto tidy; |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | /* --- Done --- */ |
| 211 | |
| 212 | d->len = l; |
| 213 | d->buf[l] = 0; |
| 214 | break; |
| 215 | |
| 216 | /* --- Tidy up if something went wrong --- */ |
| 217 | |
| 218 | tidy: |
| 219 | for (q = kp->p; q < p; q++) |
| 220 | key_unpackdone(&q->kp); |
| 221 | goto fail; |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | return (0); |
| 226 | |
| 227 | /* --- Something went wrong --- */ |
| 228 | |
| 229 | fail: |
| 230 | if (kd == &kp->kd) |
| 231 | key_destroy(kd); |
| 232 | return (err); |
| 233 | } |
| 234 | |
| 235 | /* --- @key_unpackdone@ --- * |
| 236 | * |
| 237 | * Arguments: @key_packdef *kp@ = pointer to packing definition |
| 238 | * |
| 239 | * Returns: --- |
| 240 | * |
| 241 | * Use: Frees the key components contained within a packing |
| 242 | * definition, created during key unpacking. |
| 243 | */ |
| 244 | |
| 245 | void key_unpackdone(key_packdef *kp) |
| 246 | { |
| 247 | if (kp->kd.e & KF_TEMP) |
| 248 | key_destroy(&kp->kd); |
| 249 | if ((kp->kd.e & KF_ENCMASK) == KENC_STRUCT) { |
| 250 | key_packstruct *p; |
| 251 | for (p = kp->p; p->name; p++) |
| 252 | key_unpackdone(&p->kp); |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | /*----- That's all, folks -------------------------------------------------*/ |