diff options
Diffstat (limited to 'kbx/keybox-blob.c')
| -rw-r--r-- | kbx/keybox-blob.c | 755 |
1 files changed, 755 insertions, 0 deletions
diff --git a/kbx/keybox-blob.c b/kbx/keybox-blob.c new file mode 100644 index 000000000..7db62165a --- /dev/null +++ b/kbx/keybox-blob.c @@ -0,0 +1,755 @@ +/* keybox-blob.c - KBX Blob handling + * Copyright (C) 2000, 2001 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * GnuPG 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + + +/* The keybox data formats + +The KeyBox uses an augmented OpenPGP/X.509 key format. This makes +random access to a keyblock/Certificate easier and also gives the +opportunity to store additional information (e.g. the fingerprint) +along with the key. All integers are stored in network byte order, +offsets are counted from the beginning of the Blob. + +The first record of a plain KBX file has a special format: + + u32 length of the first record + byte Blob type (1) + byte version number (1) + byte reserved + byte reserved + u32 magic 'KBXf' + byte pgp_marginals used for validity calculation of this file + byte pgp_completes ditto. + byte pgp_cert_depth ditto. + +The OpenPGP KBX Blob looks like this: + + u32 length of this blob (including these 4 bytes) + byte Blob type (2) + byte version number of this blob type (1) + u16 Blob flags + bit 0 = contains secret key material + + u32 offset to the OpenPGP keyblock + u32 length of the keyblock + u16 number of keys (at least 1!) + u16 size of additional key information + n times: + b20 The keys fingerprint + (fingerprints are always 20 bytes, MD5 left padded with zeroes) + u32 offset to the n-th key's keyID (a keyID is always 8 byte) + u16 special key flags + bit 0 = + u16 reserved + u16 number of user IDs + u16 size of additional user ID information + n times: + u32 offset to the n-th user ID + u32 length of this user ID. + u16 special user ID flags. + bit 0 = + byte validity + byte reserved + u16 number of signatures + u16 size of signature information (4) + u32 expiration time of signature with some special values: + 0x00000000 = not checked + 0x00000001 = missing key + 0x00000002 = bad signature + 0x10000000 = valid and expires at some date in 1978. + 0xffffffff = valid and does not expire + u8 assigned ownertrust + u8 all_validity + u16 reserved + u32 recheck_after + u32 Newest timestamp in the keyblock (useful for KS syncronsiation?) + u32 Blob created at + u32 size of reserved space (not including this field) + reserved space + + Here we might want to put other data + + Here comes the keyblock + + maybe we put a signature here later. + + b16 MD5 checksum (useful for KS syncronisation) + +*/ + + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <assert.h> +#include <gcrypt.h> + +#include "keybox-defs.h" + +/* special values of the signature status */ +#define SF_NONE(a) ( !(a) ) +#define SF_NOKEY(a) ((a) & (1<<0)) +#define SF_BAD(a) ((a) & (1<<1)) +#define SF_VALID(a) ((a) & (1<<29)) + + +struct membuf { + size_t len; + size_t size; + char *buf; + int out_of_core; +}; + + +/* #if MAX_FINGERPRINT_LEN < 20 */ +/* #error fingerprints are 20 bytes */ +/* #endif */ + +struct keyboxblob_key { + char fpr[20]; + u32 off_kid; + ulong off_kid_addr; + u16 flags; +}; +struct keyboxblob_uid { + ulong off_addr; + u32 len; + u16 flags; + byte validity; +}; + +struct keyid_list { + struct keyid_list *next; + int seqno; + byte kid[8]; +}; + +struct fixup_list { + struct fixup_list *next; + u32 off; + u32 val; +}; + + +struct keyboxblob { + byte *blob; + size_t bloblen; + + /* stuff used only by keybox_create_blob */ + int nkeys; + struct keyboxblob_key *keys; + int nuids; + struct keyboxblob_uid *uids; + int nsigs; + u32 *sigs; + struct fixup_list *fixups; + + struct keyid_list *temp_kids; + struct membuf *buf; /* temporary store for the blob */ +}; + + + +/* A simple implemnation of a dynamic buffer. Use init_membuf() to + create a buffer, put_membuf to append bytes and get_membuf to + release and return the buffer. Allocation errors are detected but + only returned at the final get_membuf(), this helps not to clutter + the code with out of core checks. */ + +static void +init_membuf (struct membuf *mb, int initiallen) +{ + mb->len = 0; + mb->size = initiallen; + mb->out_of_core = 0; + mb->buf = xtrymalloc (initiallen); + if (!mb->buf) + mb->out_of_core = 1; +} + +static void +put_membuf (struct membuf *mb, const void *buf, size_t len) +{ + if (mb->out_of_core) + return; + + if (mb->len + len >= mb->size) + { + char *p; + + mb->size += len + 1024; + p = xtryrealloc (mb->buf, mb->size); + if (!p) + { + mb->out_of_core = 1; + return; + } + mb->buf = p; + } + memcpy (mb->buf + mb->len, buf, len); + mb->len += len; +} + +static void * +get_membuf (struct membuf *mb, size_t *len) +{ + char *p; + + if (mb->out_of_core) + { + xfree (mb->buf); + mb->buf = NULL; + return NULL; + } + + p = mb->buf; + *len = mb->len; + mb->buf = NULL; + mb->out_of_core = 1; /* don't allow a reuse */ + return p; +} + + +static void +put8 (struct membuf *mb, byte a ) +{ + put_membuf (mb, &a, 1); +} + +static void +put16 (struct membuf *mb, u16 a ) +{ + unsigned char tmp[2]; + tmp[0] = a>>8; + tmp[1] = a; + put_membuf (mb, tmp, 2); +} + +static void +put32 (struct membuf *mb, u32 a ) +{ + unsigned char tmp[4]; + tmp[0] = a>>24; + tmp[1] = a>>16; + tmp[2] = a>>8; + tmp[3] = a; + put_membuf (mb, tmp, 4); +} + + +/* + Some wrappers +*/ + +static u32 +make_timestamp (void) +{ + return time(NULL); +} + + + +#ifdef KEYBOX_WITH_OPENPGP +/* + OpenPGP specific stuff +*/ + + +/* + We must store the keyid at some place because we can't calculate the + offset yet. This is only used for v3 keyIDs. Function returns an + index value for later fixup or -1 for out of core. The value must be + a non-zero value */ +static int +pgp_temp_store_kid (KEYBOXBLOB blob, PKT_public_key *pk) +{ + struct keyid_list *k, *r; + + k = xtrymalloc (sizeof *k); + if (!k) + return -1; + k->kid[0] = pk->keyid[0] >> 24 ; + k->kid[1] = pk->keyid[0] >> 16 ; + k->kid[2] = pk->keyid[0] >> 8 ; + k->kid[3] = pk->keyid[0] ; + k->kid[4] = pk->keyid[0] >> 24 ; + k->kid[5] = pk->keyid[0] >> 16 ; + k->kid[6] = pk->keyid[0] >> 8 ; + k->kid[7] = pk->keyid[0] ; + k->seqno = 0; + k->next = blob->temp_kids; + blob->temp_kids = k; + for (r=k; r; r = r->next) + k->seqno++; + + return k->seqno; +} + +static int +pgp_create_key_part (KEYBOXBLOB blob, KBNODE keyblock) +{ + KBNODE node; + size_t fprlen; + int n; + + for (n=0, node = keyblock; node; node = node->next) + { + if ( node->pkt->pkttype == PKT_PUBLIC_KEY + || node->pkt->pkttype == PKT_PUBLIC_SUBKEY ) + { + PKT_public_key *pk = node->pkt->pkt.public_key; + char tmp[20]; + + fingerprint_from_pk (pk, tmp , &fprlen); + memcpy (blob->keys[n].fpr, tmp, 20); + if ( fprlen != 20 ) /*v3 fpr - shift right and fill with zeroes*/ + { + assert (fprlen == 16); + memmove (blob->keys[n].fpr+4, blob->keys[n].fpr, 16); + memset (blob->keys[n].fpr, 0, 4); + blob->keys[n].off_kid = pgp_temp_store_kid (blob, pk); + } + else + { + blob->keys[n].off_kid = 0; /* will be fixed up later */ + } + blob->keys[n].flags = 0; + n++; + } + else if ( node->pkt->pkttype == PKT_SECRET_KEY + || node->pkt->pkttype == PKT_SECRET_SUBKEY ) + { + never_reached (); /* actually not yet implemented */ + } + } + assert (n == blob->nkeys); + return 0; +} + +static int +pgp_create_uid_part (KEYBOXBLOB blob, KBNODE keyblock) +{ + KBNODE node; + int n; + + for (n=0, node = keyblock; node; node = node->next) + { + if (node->pkt->pkttype == PKT_USER_ID) + { + PKT_user_id *u = node->pkt->pkt.user_id; + + blob->uids[n].len = u->len; + blob->uids[n].flags = 0; + blob->uids[n].validity = 0; + n++; + } + } + assert (n == blob->nuids); + return 0; +} + +static int +pgp_create_sig_part (KEYBOXBLOB blob, KBNODE keyblock) +{ + KBNODE node; + int n; + + for (n=0, node = keyblock; node; node = node->next) + { + if (node->pkt->pkttype == PKT_SIGNATURE) + { + PKT_signature *sig = node->pkt->pkt.signature; + + blob->sigs[n] = 0; /* FIXME: check the signature here */ + n++; + } + } + assert( n == blob->nsigs ); + return 0; +} + +static int +pgp_create_blob_keyblock (KEYBOXBLOB blob, KBNODE keyblock) +{ + struct membuf *a = blob->buf; + KBNODE node; + int rc; + int n; + u32 kbstart = a->len; + + { + struct fixup_list *fl = xtrycalloc(1, sizeof *fl ); + + if (!fl) + return KEYBOX_Out_Of_Core; + fl->off = 8; + fl->val = kbstart; + fl->next = blob->fixups; + blob->fixups = fl; + } + + for (n = 0, node = keyblock; node; node = node->next) + { + rc = build_packet ( a, node->pkt ); + if ( rc ) { + gpg_log_error ("build_packet(%d) for keyboxblob failed: %s\n", + node->pkt->pkttype, gpg_errstr(rc) ); + return GPGERR_WRITE_FILE; + } + if ( node->pkt->pkttype == PKT_USER_ID ) + { + PKT_user_id *u = node->pkt->pkt.user_id; + /* build_packet has set the offset of the name into u ; + * now we can do the fixup */ + struct fixup_list *fl = xcalloc(1, sizeof *fl ); /* fixme */ + fl->off = blob->uids[n].off_addr; + fl->val = u->stored_at; + fl->next = blob->fixups; + blob->fixups = fl; + n++; + } + } + assert (n == blob->nuids); + + { + struct fixup_list *fl = xcalloc(1, sizeof *fl ); /* fixme */ + + fl->off = 12; + fl->val = a->len - kbstart; + fl->next = blob->fixups; + blob->fixups = fl; + } + + return 0; +} + +#endif /*KEYBOX_WITH_OPENPGP*/ + + +#ifdef KEYBOX_WITH_X509 +/* + X.509 specific stuff + */ + +#endif /*KEYBOX_WITH_X509*/ + +/* Write a stored keyID out to the buffer */ +static void +write_stored_kid (KEYBOXBLOB blob, int seqno) +{ + struct keyid_list *r; + + for ( r = blob->temp_kids; r; r = r->next ) + { + if (r->seqno == seqno ) + { + put_membuf (blob->buf, r->kid, 8); + return; + } + } + never_reached (); +} + +/* Release a list of key IDs */ +static void +release_kid_list (struct keyid_list *kl) +{ + struct keyid_list *r, *r2; + + for ( r = kl; r; r = r2 ) + { + r2 = r->next; + xfree (r); + } +} + + + +static int +create_blob_header (KEYBOXBLOB blob, int blobtype) +{ + struct membuf *a = blob->buf; + int i; + + put32 ( a, 0 ); /* blob length, needs fixup */ + put8 ( a, blobtype); + put8 ( a, 1 ); /* blob type version */ + put16 ( a, 0 ); /* blob flags */ + + put32 ( a, 0 ); /* offset to the raw data, needs fixup */ + put32 ( a, 0 ); /* length of the raw data, needs fixup */ + + put16 ( a, blob->nkeys ); + put16 ( a, 20 + 4 + 2 + 2 ); /* size of key info */ + for ( i=0; i < blob->nkeys; i++ ) + { + put_membuf (a, blob->keys[i].fpr, 20); + blob->keys[i].off_kid_addr = a->len; + put32 ( a, 0 ); /* offset to keyid, fixed up later */ + put16 ( a, blob->keys[i].flags ); + put16 ( a, 0 ); /* reserved */ + } + + put16 ( a, blob->nuids ); + put16 ( a, 4 + 4 + 2 + 1 + 1 ); /* size of uid info */ + for (i=0; i < blob->nuids; i++) + { + blob->uids[i].off_addr = a->len; + put32 ( a, 0 ); /* offset to userid, fixed up later */ + put32 ( a, blob->uids[i].len ); + put16 ( a, blob->uids[i].flags ); + put8 ( a, 0 ); /* validity */ + put8 ( a, 0 ); /* reserved */ + } + + put16 ( a, blob->nsigs ); + put16 ( a, 4 ); /* size of sig info */ + for (i=0; i < blob->nsigs; i++) + { + put32 ( a, blob->sigs[i]); + } + + put8 ( a, 0 ); /* assigned ownertrust */ + put8 ( a, 0 ); /* validity of all user IDs */ + put16 ( a, 0 ); /* reserved */ + put32 ( a, 0 ); /* time of next recheck */ + put32 ( a, 0 ); /* newest timestamp (none) */ + put32 ( a, make_timestamp() ); /* creation time */ + put32 ( a, 0 ); /* size of reserved space */ + /* reserved space (which is currently of size 0) */ + + /* We need to store the keyids for all pgp v3 keys because those key + IDs are not part of the fingerprint. While we are doing that, we + fixup all the keyID offsets */ + for (i=0; i < blob->nkeys; i++ ) + { + struct fixup_list *fl = xtrycalloc(1, sizeof *fl ); + + if (!fl) + return KEYBOX_Out_Of_Core; + + fl->off = blob->keys[i].off_kid_addr; + fl->next = blob->fixups; + blob->fixups = fl; + + if (blob->keys[i].off_kid) + { /* this is a v3 one */ + fl->val = a->len; + write_stored_kid (blob, blob->keys[i].off_kid); + } + else + { /* the better v4 key IDs - just store an offset 8 bytes back */ + fl->val = blob->keys[i].off_kid_addr - 8; + } + } + + return 0; +} + + + +static int +create_blob_trailer (KEYBOXBLOB blob) +{ + return 0; +} + + +static int +create_blob_finish (KEYBOXBLOB blob) +{ + struct membuf *a = blob->buf; + byte *p; + char *pp; + int i; + size_t n; + + /* write a placeholder for the checksum */ + for (i = 0; i < 16; i++ ) + put32 (a, 0); + + /* get the memory area */ + p = a->buf; + n = a->len; + assert (n >= 20); + + /* fixup the length */ + { + struct fixup_list *fl = xtrycalloc(1, sizeof *fl); + if (!fl) + return KEYBOX_Out_Of_Core; + fl->off = 0; + fl->val = n; + fl->next = blob->fixups; + blob->fixups = fl; + } + + /* do the fixups */ + { + struct fixup_list *fl; + for (fl = blob->fixups; fl; fl = fl->next) + { + assert (fl->off+4 <= n); + p[fl->off+0] = fl->val >> 24; + p[fl->off+1] = fl->val >> 16; + p[fl->off+2] = fl->val >> 8; + p[fl->off+3] = fl->val; + } + } + + /* calculate and store the MD5 checksum */ + gcry_md_hash_buffer (GCRY_MD_MD5, p + n - 16, p, n - 16); + + pp = xtrymalloc (n); + if ( !pp ) + return KEYBOX_Out_Of_Core; + memcpy (pp , p, n); + blob->blob = pp; + blob->bloblen = n; + + return 0; +} + + +#ifdef KEYBOX_WITH_OPENPGP + +int +_keybox_create_pgp_blob (KEYBOXBLOB *r_blob, KBNODE keyblock) +{ + int rc = 0; + KBNODE node; + KEYBOXBLOB blob; + + *r_blob = NULL; + blob = xtrycalloc (1, sizeof *blob); + if( !blob ) + return KEYBOX_Out_Of_Core; + + /* fixme: Do some sanity checks on the keyblock */ + + /* count userids and keys so that we can allocate the arrays */ + for (node = keyblock; node; node = node->next) + { + switch (node->pkt->pkttype) + { + case PKT_PUBLIC_KEY: + case PKT_SECRET_KEY: + case PKT_PUBLIC_SUBKEY: + case PKT_SECRET_SUBKEY: blob->nkeys++; break; + case PKT_USER_ID: blob->nuids++; break; + case PKT_SIGNATURE: blob->nsigs++; break; + default: break; + } + } + + blob->keys = xtrycalloc (blob->nkeys, sizeof *blob->keys ); + blob->uids = xtrycalloc (blob->nuids, sizeof *blob->uids ); + blob->sigs = xtrycalloc (blob->nsigs, sizeof *blob->sigs ); + if (!blob->keys || !blob->uids || !blob->sigs) + { + rc = KEYBOX_Out_Of_Core; + goto leave; + } + + rc = pgp_create_key_part ( blob, keyblock ); + if (rc) + goto leave; + rc = pgp_create_uid_part ( blob, keyblock ); + if (rc) + goto leave; + rc = pgp_create_sig_part ( blob, keyblock ); + if (rc) + goto leave; + + init_membuf (blob->buf, 1024); + rc = create_blob_header (blob, BLOBTYPE_OPENPGP); + if (rc) + goto leave; + rc = pgp_create_blob_keyblock (blob, keyblock); + if (rc) + goto leave; + rc = create_blob_trailer (blob); + if (rc) + goto leave; + rc = create_blob_finish ( blob ); + if (rc) + goto leave; + + + leave: + release_kid_list (blob->temp_kids); + blob->temp_kids = NULL; + if (rc) + { + keybox_release_blob (blob); + *r_blob = NULL; + } + else + { + *r_blob = blob; + } + return rc; +} +#endif /*KEYBOX_WITH_OPENPGP*/ + + + +int +_keybox_new_blob (KEYBOXBLOB *r_blob, char *image, size_t imagelen) +{ + KEYBOXBLOB blob; + + *r_blob = NULL; + blob = xtrycalloc (1, sizeof *blob); + if (!blob) + return KEYBOX_Out_Of_Core; + + blob->blob = image; + blob->bloblen = imagelen; + *r_blob = blob; + return 0; +} + +void +_keybox_release_blob (KEYBOXBLOB blob) +{ + if (!blob) + return; +/* if (blob->buf) */ +/* iobuf_cancel( blob->buf ); */ + xfree (blob->keys ); + xfree (blob->uids ); + xfree (blob->sigs ); + xfree (blob->blob ); + xfree (blob ); +} + + + +const char * +_keybox_get_blob_image ( KEYBOXBLOB blob, size_t *n ) +{ + *n = blob->bloblen; + return blob->blob; +} + + |