/* keybox-blob.c - KBX Blob handling * Copyright (C) 2000, 2001, 2002, 2003, 2008 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 3 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, see . */ /* 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' u32 reserved u32 file_created_at u32 last_maintenance_run u32 reserved u32 reserved The OpenPGP and X.509 blob are very similiar, things which are X.509 specific are noted like [X.509: xxx] u32 length of this blob (including these 4 bytes) byte Blob type (2) [X509: 3] byte version number of this blob type (1) u16 Blob flags bit 0 = contains secret key material bit 1 = ephemeral blob (e.g. used while quering external resources) u32 offset to the OpenPGP keyblock or X509 DER encoded certificate u32 and its length u16 number of keys (at least 1!) [X509: always 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) or 0 if not known which is the case only for X509. u16 special key flags bit 0 = qualified signature (not yet implemented} u16 reserved u16 size of serialnumber(may be zero) n u16 (see above) bytes of serial number 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 [For X509, the first user ID is the Issuer, the second the Subject and the others are subjectAltNames] 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 [X509: not used] u8 all_validity OpenPGP: see ../g10/trustdb/TRUST_* [not yet used] X509: Bit 4 set := key has been revoked. Note that this value matches TRUST_FLAG_REVOKED 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), we might also want to use a mac here. b4 reserved */ #include #include #include #include #include #include #include #include "keybox-defs.h" #include #ifdef KEYBOX_WITH_OPENPGP /* include stuff to parse the packets */ #endif #ifdef KEYBOX_WITH_X509 #include #endif /* 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; char *name; /* used only with x509 */ 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; off_t fileoffset; /* stuff used only by keybox_create_blob */ unsigned char *serialbuf; const unsigned char *serial; size_t seriallen; int nkeys; struct keyboxblob_key *keys; int nuids; struct keyboxblob_uid *uids; int nsigs; u32 *sigs; struct fixup_list *fixups; int fixup_out_of_core; struct keyid_list *temp_kids; struct membuf bufbuf; /* temporary store for the blob */ struct membuf *buf; }; /* A simple implemention 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); } /* Store a value in the fixup list */ static void add_fixup (KEYBOXBLOB blob, u32 off, u32 val) { struct fixup_list *fl; if (blob->fixup_out_of_core) return; fl = xtrycalloc(1, sizeof *fl); if (!fl) blob->fixup_out_of_core = 1; else { fl->off = off; fl->val = val; fl->next = blob->fixups; blob->fixups = fl; } } /* 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; add_fixup (blob, kbstart); 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 */ add_fixup (blob, blob->uids[n].off_addr, u->stored_at); n++; } } assert (n == blob->nuids); add_fixup (blob, a->len - kbstart); return 0; } #endif /*KEYBOX_WITH_OPENPGP*/ #ifdef KEYBOX_WITH_X509 /* X.509 specific stuff */ /* Write the raw certificate out */ static int x509_create_blob_cert (KEYBOXBLOB blob, ksba_cert_t cert) { struct membuf *a = blob->buf; const unsigned char *image; size_t length; u32 kbstart = a->len; /* Store our offset for later fixup */ add_fixup (blob, 8, kbstart); image = ksba_cert_get_image (cert, &length); if (!image) return gpg_error (GPG_ERR_GENERAL); put_membuf (a, image, length); add_fixup (blob, 12, a->len - kbstart); return 0; } #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, int as_ephemeral) { 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, as_ephemeral? 2:0 ); /* 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->seriallen); /*fixme: check that it fits into 16 bits*/ if (blob->serial) put_membuf (a, blob->serial, blob->seriallen); 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) */ /* space where we write keyIDs and and other stuff so that the pointers can actually point to somewhere */ if (blobtype == BLOBTYPE_PGP) { /* 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++ ) { if (blob->keys[i].off_kid) { /* this is a v3 one */ add_fixup (blob, blob->keys[i].off_kid_addr, a->len); write_stored_kid (blob, blob->keys[i].off_kid); } else { /* the better v4 key IDs - just store an offset 8 bytes back */ add_fixup (blob, blob->keys[i].off_kid_addr, blob->keys[i].off_kid_addr - 8); } } } if (blobtype == BLOBTYPE_X509) { /* We don't want to point to ASN.1 encoded UserIDs (DNs) but to the utf-8 string represenation of them */ for (i=0; i < blob->nuids; i++ ) { if (blob->uids[i].name) { /* this is a v3 one */ add_fixup (blob, blob->uids[i].off_addr, a->len); put_membuf (blob->buf, blob->uids[i].name, blob->uids[i].len); } } } return 0; } static int create_blob_trailer (KEYBOXBLOB blob) { (void)blob; return 0; } static int create_blob_finish (KEYBOXBLOB blob) { struct membuf *a = blob->buf; unsigned char *p; unsigned char *pp; int i; size_t n; /* write a placeholder for the checksum */ for (i = 0; i < 16; i++ ) put32 (a, 0); /* Hmmm: why put32() ?? */ /* get the memory area */ n = 0; /* (Just to avoid compiler warning.) */ p = get_membuf (a, &n); if (!p) return gpg_error (GPG_ERR_ENOMEM); assert (n >= 20); /* fixup the length */ add_fixup (blob, 0, n); /* do the fixups */ if (blob->fixup_out_of_core) return gpg_error (GPG_ERR_ENOMEM); { 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 gpg_error_from_syserror (); 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 as_ephemeral) { int rc = 0; KBNODE node; KEYBOXBLOB blob; *r_blob = NULL; blob = xtrycalloc (1, sizeof *blob); if (!blob) return gpg_error_from_syserror (); /* 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 = gpg_error (GPG_ERR_ENOMEM); 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->bufbuf, 1024); blob->buf = &blob->bufbuf; rc = create_blob_header (blob, BLOBTYPE_OPENPGP, as_ephemeral); 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*/ #ifdef KEYBOX_WITH_X509 /* Return an allocated string with the email address extracted from a DN. Note hat we use this code also in ../sm/keylist.c. */ static char * x509_email_kludge (const char *name) { const char *p, *string; unsigned char *buf; int n; string = name; for (;;) { p = strstr (string, "1.2.840.113549.1.9.1=#"); if (!p) return NULL; if (p == name || (p > string+1 && p[-1] == ',' && p[-2] != '\\')) { name = p + 22; break; } string = p + 22; } /* This looks pretty much like an email address in the subject's DN we use this to add an additional user ID entry. This way, OpenSSL generated keys get a nicer and usable listing. */ for (n=0, p=name; hexdigitp (p) && hexdigitp (p+1); p +=2, n++) ; if (!n) return NULL; buf = xtrymalloc (n+3); if (!buf) return NULL; /* oops, out of core */ *buf = '<'; for (n=1, p=name; hexdigitp (p); p +=2, n++) buf[n] = xtoi_2 (p); buf[n++] = '>'; buf[n] = 0; return (char*)buf; } /* Note: We should move calculation of the digest into libksba and remove that parameter */ int _keybox_create_x509_blob (KEYBOXBLOB *r_blob, ksba_cert_t cert, unsigned char *sha1_digest, int as_ephemeral) { int i, rc = 0; KEYBOXBLOB blob; unsigned char *sn; char *p; char **names = NULL; size_t max_names; *r_blob = NULL; blob = xtrycalloc (1, sizeof *blob); if( !blob ) return gpg_error_from_syserror (); sn = ksba_cert_get_serial (cert); if (sn) { size_t n, len; n = gcry_sexp_canon_len (sn, 0, NULL, NULL); if (n < 2) { xfree (sn); return gpg_error (GPG_ERR_GENERAL); } blob->serialbuf = sn; sn++; n--; /* skip '(' */ for (len=0; n && *sn && *sn != ':' && digitp (sn); n--, sn++) len = len*10 + atoi_1 (sn); if (*sn != ':') { xfree (blob->serialbuf); blob->serialbuf = NULL; return gpg_error (GPG_ERR_GENERAL); } sn++; blob->serial = sn; blob->seriallen = len; } blob->nkeys = 1; /* create list of names */ blob->nuids = 0; max_names = 100; names = xtrymalloc (max_names * sizeof *names); if (!names) { rc = gpg_error_from_syserror (); goto leave; } p = ksba_cert_get_issuer (cert, 0); if (!p) { rc = gpg_error (GPG_ERR_MISSING_VALUE); goto leave; } names[blob->nuids++] = p; for (i=0; (p = ksba_cert_get_subject (cert, i)); i++) { if (blob->nuids >= max_names) { char **tmp; max_names += 100; tmp = xtryrealloc (names, max_names * sizeof *names); if (!tmp) { rc = gpg_error_from_syserror (); goto leave; } } names[blob->nuids++] = p; if (!i && (p=x509_email_kludge (p))) names[blob->nuids++] = p; /* due to !i we don't need to check bounds*/ } /* space for signature information */ blob->nsigs = 1; 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 = gpg_error (GPG_ERR_ENOMEM); goto leave; } memcpy (blob->keys[0].fpr, sha1_digest, 20); blob->keys[0].off_kid = 0; /* We don't have keyids */ blob->keys[0].flags = 0; /* issuer and subject names */ for (i=0; i < blob->nuids; i++) { blob->uids[i].name = names[i]; blob->uids[i].len = strlen(names[i]); names[i] = NULL; blob->uids[i].flags = 0; blob->uids[i].validity = 0; } xfree (names); names = NULL; /* signatures */ blob->sigs[0] = 0; /* not yet checked */ /* Create a temporary buffer for further processing */ init_membuf (&blob->bufbuf, 1024); blob->buf = &blob->bufbuf; /* write out what we already have */ rc = create_blob_header (blob, BLOBTYPE_X509, as_ephemeral); if (rc) goto leave; rc = x509_create_blob_cert (blob, cert); 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 (blob && names) { for (i=0; i < blob->nuids; i++) xfree (names[i]); } xfree (names); if (rc) { _keybox_release_blob (blob); *r_blob = NULL; } else { *r_blob = blob; } return rc; } #endif /*KEYBOX_WITH_X509*/ int _keybox_new_blob (KEYBOXBLOB *r_blob, unsigned char *image, size_t imagelen, off_t off) { KEYBOXBLOB blob; *r_blob = NULL; blob = xtrycalloc (1, sizeof *blob); if (!blob) return gpg_error_from_syserror (); blob->blob = image; blob->bloblen = imagelen; blob->fileoffset = off; *r_blob = blob; return 0; } void _keybox_release_blob (KEYBOXBLOB blob) { int i; if (!blob) return; /* hmmm: release membuf here?*/ xfree (blob->keys ); xfree (blob->serialbuf); for (i=0; i < blob->nuids; i++) xfree (blob->uids[i].name); xfree (blob->uids ); xfree (blob->sigs ); xfree (blob->blob ); xfree (blob ); } const unsigned char * _keybox_get_blob_image ( KEYBOXBLOB blob, size_t *n ) { *n = blob->bloblen; return blob->blob; } off_t _keybox_get_blob_fileoffset (KEYBOXBLOB blob) { return blob->fileoffset; } void _keybox_update_header_blob (KEYBOXBLOB blob) { if (blob->bloblen >= 32 && blob->blob[4] == BLOBTYPE_HEADER) { u32 val = make_timestamp (); /* Update the last maintenance run times tamp. */ blob->blob[20] = (val >> 24); blob->blob[20+1] = (val >> 16); blob->blob[20+2] = (val >> 8); blob->blob[20+3] = (val ); } }