--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: key-data.c,v 1.1 1999/12/22 15:47:48 mdw Exp $
+ *
+ * Encoding and decoding of key data
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: key-data.c,v $
+ * Revision 1.1 1999/12/22 15:47:48 mdw
+ * Major key-management revision.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <mLib/alloc.h>
+#include <mLib/base64.h>
+#include <mLib/bits.h>
+#include <mLib/dstr.h>
+#include <mLib/sub.h>
+#include <mLib/sym.h>
+
+#include "key.h"
+#include "mp.h"
+#include "mptext.h"
+
+/*----- Disposal ----------------------------------------------------------*/
+
+/* --- @key_destroy@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data to destroy
+ *
+ * Returns: ---
+ *
+ * Use: Destroys a lump of key data.
+ */
+
+void key_destroy(key_data *k)
+{
+ switch (k->e & KF_ENCMASK) {
+ case KENC_BINARY:
+ case KENC_ENCRYPT:
+ if (k->e & KF_BURN)
+ memset(k->u.k.k, 0, k->u.k.sz);
+ sub_free(k->u.k.k, k->u.k.sz);
+ break;
+ case KENC_MP:
+ mp_drop(k->u.m);
+ break;
+ case KENC_STRUCT: {
+ sym_iter i;
+ key_struct *ks;
+
+ for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; )
+ key_destroy(&ks->k);
+ sym_destroy(&k->u.s);
+ } break;
+ }
+}
+
+/*----- Setting new values ------------------------------------------------*/
+
+/* --- @key_binary@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const void *p@ = pointer to key data
+ * @size_t sz@ = size of the key data
+ *
+ * Returns: ---
+ *
+ * Use: Sets a binary key in a key data block.
+ */
+
+void key_binary(key_data *k, const void *p, size_t sz)
+{
+ k->e = (k->e & ~KF_ENCMASK) | KENC_BINARY;
+ k->u.k.k = sub_alloc(sz);
+ memcpy(k->u.k.k, p, sz);
+ k->u.k.sz = sz;
+}
+
+/* --- @key_encrypted@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const void *p@ = pointer to key data
+ * @size_t sz@ = size of the key data
+ *
+ * Returns: ---
+ *
+ * Use: Sets an encrypted key in a key data block.
+ */
+
+void key_encrypted(key_data *k, const void *p, size_t sz)
+{
+ k->e = (k->e & ~KF_ENCMASK) | KENC_ENCRYPT;
+ k->u.k.k = sub_alloc(sz);
+ memcpy(k->u.k.k, p, sz);
+ k->u.k.sz = sz;
+}
+
+/* --- @key_mp@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @mp *m@ = pointer to the value to set
+ *
+ * Returns: ---
+ *
+ * Use: Sets a multiprecision integer key in a key block.
+ */
+
+void key_mp(key_data *k, mp *m)
+{
+ k->e = (k->e & ~KF_ENCMASK) | KENC_MP;
+ k->u.m = MP_COPY(m);
+}
+
+/* --- @key_structure@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a structured key type.
+ */
+
+void key_structure(key_data *k)
+{
+ k->e = KENC_STRUCT;
+ sym_create(&k->u.s);
+}
+
+/* --- @key_structfind@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const char *tag@ = pointer to tag string
+ *
+ * Returns: Pointer to key data block, or null.
+ *
+ * Use: Looks up the tag in a structured key.
+ */
+
+key_data *key_structfind(key_data *k, const char *tag)
+{
+ key_struct *ks;
+ assert(((void)"Key is not structured", k->e == KENC_STRUCT));
+ ks = sym_find(&k->u.s, tag, -1, 0, 0);
+ return (&ks->k);
+}
+
+/* --- @key_structcreate@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const char *tag@ = pointer to tag string
+ *
+ * Returns: Pointer to newly created key data.
+ *
+ * Use: Creates a new uninitialized subkey.
+ */
+
+key_data *key_structcreate(key_data *k, const char *tag)
+{
+ key_struct *ks;
+ unsigned f;
+
+ assert(((void)"Key is not structured", k->e == KENC_STRUCT));
+ ks = sym_find(&k->u.s, tag, -1, sizeof(*ks), &f);
+ if (f)
+ key_destroy(&ks->k);
+ ks->k.e = 0;
+ return (&ks->k);
+}
+
+/* --- @key_match@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const key_filter *kf@ = pointer to filter block
+ *
+ * Returns: Nonzero if the key matches the filter.
+ *
+ * Use: Checks whether a key matches a filter.
+ */
+
+int key_match(key_data *k, const key_filter *kf)
+{
+ sym_iter i;
+ key_struct *ks;
+
+ if (!kf)
+ return (1);
+ if ((k->e & KF_ENCMASK) != KENC_STRUCT)
+ return ((k->e & kf->m) == kf->f);
+
+ for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
+ if (key_match(&ks->k, kf))
+ return (1);
+ }
+ return (0);
+}
+
+/* --- @key_do@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const key_filter *kf@ = pointer to filter block
+ * @dstr *d@ = pointer to base string
+ * @int (*func)(key_data *kd, dstr *d, void *p@ = function
+ * @void *p@ = argument to function
+ *
+ * Returns: Nonzero return code from function, or zero.
+ *
+ * Use: Runs a function over all the leaves of a key.
+ */
+
+int key_do(key_data *k, const key_filter *kf, dstr *d,
+ int (*func)(key_data */*kd*/, dstr */*d*/, void */*p*/),
+ void *p)
+{
+ if (!KEY_MATCH(k, kf))
+ return (0);
+ if ((k->e & KF_ENCMASK) != KENC_STRUCT)
+ return (func(k, d, p));
+ else {
+ sym_iter i;
+ key_struct *ks;
+ size_t n;
+ int rc;
+
+ if (d)
+ n = d->len;
+ for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
+ if (d) {
+ d->len = n;
+ dstr_putf(d, ".%s", SYM_NAME(ks));
+ }
+ if ((rc = key_do(&ks->k, kf, d, func, p)) != 0)
+ return (rc);
+ }
+ return (0);
+ }
+}
+
+/*----- Copying -----------------------------------------------------------*/
+
+/* --- @key_copy@ --- *
+ *
+ * Arguments: @key_data *kd@ = pointer to destination data block
+ * @key_data *k@ = pointer to source data block
+ * @const key_filter *kf@ = pointer to filter block
+ *
+ * Returns: Nonzero if an item was actually copied.
+ *
+ * Use: Copies a chunk of key data from one place to another.
+ */
+
+int key_copy(key_data *kd, key_data *k, const key_filter *kf)
+{
+ kd->e = k->e;
+
+ if (!KEY_MATCH(kd, kf))
+ return (0);
+ switch (k->e & KF_ENCMASK) {
+
+ /* --- Plain binary data --- */
+
+ case KENC_BINARY:
+ case KENC_ENCRYPT:
+ kd->u.k.k = sub_alloc(k->u.k.sz);
+ memcpy(kd->u.k.k, k->u.k.k, k->u.k.sz);
+ kd->u.k.sz = k->u.k.sz;
+ break;
+
+ /* --- Multiprecision integers --- */
+
+ case KENC_MP:
+ kd->u.m = MP_COPY(k->u.m);
+ break;
+
+ /* --- Structured key data --- */
+
+ case KENC_STRUCT: {
+ sym_iter i;
+ key_struct *ks;
+ int rc = 0;
+
+ sym_create(&kd->u.s);
+ for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
+ unsigned f;
+ key_struct *kks = sym_find(&kd->u.s, SYM_NAME(ks), -1,
+ sizeof(*kks), &f);
+ assert(((void)"Duplicate subkey tags", !f));
+ if (key_copy(&kks->k, &ks->k, kf))
+ rc = 1;
+ else
+ sym_remove(&kd->u.s, kks);
+ }
+ if (!rc) {
+ sym_destroy(&kd->u.s);
+ return (0);
+ }
+ } break;
+ }
+ return (1);
+}
+
+/*----- Textual encoding --------------------------------------------------*/
+
+/* --- @key_read@ --- *
+ *
+ * Arguments: @const char *p@ = pointer to textual key representation
+ * @key_data *k@ = pointer to output block for key data
+ * @char **pp@ = where to store the end pointer
+ *
+ * Returns: Zero if all went well, nonzero if there was a problem.
+ *
+ * Use: Parses a textual key description.
+ */
+
+int key_read(const char *p, key_data *k, char **pp)
+{
+ unsigned e;
+
+ /* --- Read the encoding type --- *
+ *
+ * The key format is `[FLAGS:]DATA'. If there is no encoding type
+ * named, assume that it's `binary' for backwards compatibility.
+ */
+
+ if (strchr(p, ':') == 0)
+ e = 0;
+ else {
+ char *q;
+ if (key_readflags(p, &q, &e, 0))
+ return (-1);
+ p = q + 1;
+ }
+
+ /* --- Now scan the data based on the encoding type --- */
+
+ k->e = e;
+ switch (e & KF_ENCMASK) {
+
+ /* --- Binary encoding --- *
+ *
+ * Simply read out the Base64-encoded data. Since `,' and `]' are our
+ * delimeter characters, and they can't appear in Base64-encoded data, I
+ * can just do a simple search to find the end of the encoded data.
+ */
+
+ case KENC_BINARY:
+ case KENC_ENCRYPT: {
+ dstr d = DSTR_INIT;
+ base64_ctx b;
+ size_t sz = strcspn(p, ",]");
+
+ base64_init(&b);
+ base64_decode(&b, p, sz, &d);
+ base64_decode(&b, 0, 0, &d);
+ k->u.k.k = sub_alloc(d.len);
+ k->u.k.sz = d.len;
+ memcpy(k->u.k.k, d.buf, d.len);
+ dstr_destroy(&d);
+ p += sz;
+ } break;
+
+ /* --- Multiprecision integer encoding --- *
+ *
+ * Multiprecision integers have a convenient reading function.
+ */
+
+ case KENC_MP: {
+ char *q;
+ mp *m = mp_readstring(MP_NEW, p, &q, 0);
+ if (!m)
+ return (-1);
+ if (k->e & KF_BURN)
+ mp_burn(m);
+ k->u.m = m;
+ p = q;
+ } break;
+
+ /* --- Structured information encoding --- *
+ *
+ * The format for structured key data is `[NAME=KEY,...]', where the
+ * brackets are part of the syntax. Structured keys have no flags apart
+ * from the encoding.
+ *
+ * The binary encoding only allows names up to 255 bytes long. Check for
+ * this here.
+ */
+
+ case KENC_STRUCT: {
+ dstr d = DSTR_INIT;
+ char *q;
+
+ /* --- Read the opening bracket --- */
+
+ k->e &= KF_ENCMASK;
+ if (*p != '[')
+ return (-1);
+ p++;
+ sym_create(&k->u.s);
+
+ /* --- Read named key subparts --- */
+
+ for (;;) {
+ size_t sz;
+ key_struct *ks;
+
+ /* --- Stop if there's a close-bracket --- *
+ *
+ * This allows `[]' to be an empty structured key, which is good. It
+ * also makes `[foo=enc:bar,]' legal, and that's less good but I can
+ * live with it.
+ */
+
+ if (*p == ']')
+ break;
+
+ /* --- Read the name out and check the length --- */
+
+ if ((q = strchr(p, '=')) == 0)
+ goto fail;
+ sz = q - p;
+ if (sz >= 256)
+ goto fail;
+ DRESET(&d);
+ DPUTM(&d, p, sz);
+ DPUTZ(&d);
+
+ /* --- Add an appropriate block to the key table --- *
+ *
+ * Simply destroy old data if there's already a match.
+ */
+
+ {
+ unsigned f;
+ ks = sym_find(&k->u.s, d.buf, d.len + 1, sizeof(*ks), &f);
+ if (f)
+ key_destroy(&ks->k);
+ }
+
+ /* --- Read the key data for the subkey --- */
+
+ if (key_read(q + 1, &ks->k, &q)) {
+ sym_remove(&k->u.s, ks);
+ goto fail;
+ }
+ p = q;
+
+ /* --- Read the comma or close-bracket --- */
+
+ if (*p == ']')
+ break;
+ else if (*p == ',')
+ p++;
+ else
+ goto fail;
+ }
+
+ /* --- Step past the close bracket --- */
+
+ p++;
+ dstr_destroy(&d);
+ break;
+
+ /* --- Tidy up after a failure --- */
+
+ fail:
+ dstr_destroy(&d);
+ key_destroy(k);
+ return (-1);
+ } break;
+
+ /* --- Anything else is unknown --- */
+
+ default:
+ return (-1);
+ }
+
+ /* --- Return the end pointer --- */
+
+ if (pp)
+ *pp = (char *)p;
+ return (0);
+}
+
+/* --- @key_write@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data
+ * @dstr *d@ = destination string to write on
+ * @const key_filter *kf@ = pointer to key selection block
+ *
+ * Returns: Nonzero if an item was actually written.
+ *
+ * Use: Writes a key in a textual encoding.
+ */
+
+int key_write(key_data *k, dstr *d, const key_filter *kf)
+{
+ int rc = 0;
+ if (!KEY_MATCH(k, kf))
+ return (0);
+ switch (k->e & KF_ENCMASK) {
+ case KENC_BINARY:
+ case KENC_ENCRYPT: {
+ base64_ctx b;
+
+ if ((k->e & KF_ENCMASK) == KENC_BINARY)
+ key_writeflags(k->e, d);
+ else
+ DPUTS(d, "encrypt,secret");
+ DPUTC(d, ':');
+ base64_init(&b);
+ b.indent = "";
+ b.maxline = 0;
+ base64_encode(&b, k->u.k.k, k->u.k.sz, d);
+ base64_encode(&b, 0, 0, d);
+ rc = 1;
+ } break;
+ case KENC_MP:
+ key_writeflags(k->e, d);
+ DPUTC(d, ':');
+ mp_writedstr(k->u.m, d, 10);
+ rc = 1;
+ break;
+ case KENC_STRUCT: {
+ sym_iter i;
+ key_struct *ks;
+ char del = 0;
+ size_t n = d->len;
+
+ DPUTS(d, "struct:[");
+ for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
+ size_t o = d->len;
+ if (del)
+ DPUTC(d, del);
+ DPUTS(d, SYM_NAME(ks));
+ DPUTC(d, '=');
+ if (!key_write(&ks->k, d, kf))
+ d->len = o;
+ else {
+ del = ',';
+ rc = 1;
+ }
+ }
+ if (!rc)
+ d->len = n;
+ else
+ DPUTC(d, ']');
+ } break;
+ }
+ DPUTZ(d);
+
+ return (rc);
+}
+
+/*----- Binary encoding ---------------------------------------------------*/
+
+/* --- @key_decode@ --- *
+ *
+ * Arguments: @const void *p@ = pointer to buffer to read
+ * @size_t sz@ = size of the buffer
+ * @key_data *k@ = pointer to key data block to write to
+ *
+ * Returns: Zero if everything worked, nonzero otherwise.
+ *
+ * Use: Decodes a binary representation of a key.
+ */
+
+int key_decode(const void *p, size_t sz, key_data *k)
+{
+ const octet *q = p;
+ size_t psz;
+ unsigned e;
+
+ /* --- Parse the header information --- *
+ *
+ * Make sure the size matches external reality. Security holes have been
+ * known to creep in without this sort of check. (No, this isn't an after-
+ * the-fact patch-up.)
+ */
+
+ e = LOAD16(q);
+ psz = LOAD16(q + 2);
+ if (psz + 4 > sz)
+ return (-1);
+ k->e = e;
+
+ /* --- Now decide what to do --- */
+
+ switch (e & KF_ENCMASK) {
+
+ /* --- Plain binary data --- */
+
+ case KENC_BINARY:
+ case KENC_ENCRYPT:
+ k->u.k.k = sub_alloc(psz);
+ memcpy(k->u.k.k, q + 4, psz);
+ k->u.k.sz = psz;
+ break;
+
+ /* --- Multiprecision integer data --- */
+
+ case KENC_MP:
+ k->u.m = mp_loadb(MP_NEW, q + 4, psz);
+ if (k->e & KF_BURN)
+ mp_burn(k->u.m);
+ break;
+
+ /* --- Structured key data --- */
+
+ case KENC_STRUCT: {
+ dstr d = DSTR_INIT;
+ key_struct *ks;
+ unsigned f;
+
+ if ((k->e & ~KF_ENCMASK) || (psz & 3))
+ return (-1);
+ q += 4;
+ sym_create(&k->u.s);
+
+ while (psz) {
+
+ /* --- Read the tag string --- */
+
+ DRESET(&d);
+ sz = LOAD8(q);
+ if (sz >= psz)
+ goto fail;
+ DPUTM(&d, q + 1, sz);
+ DPUTZ(&d);
+ sz = (sz + 4) & ~3;
+ q += sz; psz -= sz;
+
+ /* --- Read the encoding and size --- */
+
+ e = LOAD16(q);
+ sz = (LOAD16(q + 2) + 7) & ~3;
+ if (sz > psz)
+ goto fail;
+
+ /* --- Create a table node and fill it in --- */
+
+ ks = sym_find(&k->u.s, d.buf, d.len + 1, sizeof(*ks), &f);
+ if (f)
+ goto fail;
+ if (key_decode(q, sz, &ks->k)) {
+ sym_remove(&k->u.s, ks);
+ goto fail;
+ }
+ psz -= sz;
+ q += sz;
+ }
+ dstr_destroy(&d);
+ break;
+
+ /* --- Tidy up after a failure --- */
+
+ fail:
+ dstr_destroy(&d);
+ key_destroy(k);
+ return (-1);
+ } break;
+
+ /* --- Everything else --- */
+
+ default:
+ return (-1);
+ }
+
+ /* --- OK, that was good --- */
+
+ return (0);
+}
+
+/* --- @key_encode@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @dstr *d@ = pointer to destination string
+ * @const key_filter *kf@ = pointer to key selection block
+ *
+ * Returns: Nonzero if an item was actually written.
+ *
+ * Use: Encodes a key block as binary data.
+ */
+
+int key_encode(key_data *k, dstr *d, const key_filter *kf)
+{
+ int rc = 0;
+ if (!KEY_MATCH(k, kf))
+ return (0);
+ switch (k->e & KF_ENCMASK) {
+ case KENC_BINARY:
+ case KENC_ENCRYPT: {
+ char *p;
+
+ DENSURE(d, (k->u.k.sz + 7) & ~3);
+ p = d->buf + d->len;
+ STORE16(p, k->e);
+ STORE16(p + 2, k->u.k.sz);
+ d->len += 4;
+ DPUTM(d, k->u.k.k, k->u.k.sz);
+ rc = 1;
+ } break;
+
+ case KENC_MP: {
+ char *p;
+ size_t sz = mp_octets(k->u.m);
+
+ DENSURE(d, (sz + 7) & ~3);
+ p = d->buf + d->len;
+ STORE16(p, k->e);
+ STORE16(p + 2, sz);
+ mp_storeb(k->u.m, p + 4, sz);
+ d->len += sz + 4;
+ rc = 1;
+ } break;
+
+ case KENC_STRUCT: {
+ size_t n;
+ char *p;
+ key_struct *ks;
+ sym_iter i;
+
+ n = d->len;
+ DENSURE(d, 4);
+ p = d->buf + n;
+ STORE16(p, k->e & KF_ENCMASK);
+ d->len += 4;
+ for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
+ size_t o = d->len;
+ DENSURE(d, 1);
+ *(octet *)(d->buf + d->len++) = strlen(SYM_NAME(ks));
+ DPUTS(d, SYM_NAME(ks));
+ while (d->len & 3)
+ DPUTC(d, 0);
+ if (key_encode(&ks->k, d, kf))
+ rc = 1;
+ else
+ d->len = o;
+ }
+ if (!rc)
+ d->len = n;
+ else {
+ p = d->buf + n + 2;
+ n = d->len - n - 4;
+ STORE16(p, n);
+ }
+ } break;
+ }
+ while (d->len & 3)
+ DPUTC(d, 0);
+ return (rc);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff