diff options
Diffstat (limited to 'third_party/heimdal/lib/hdb/mkey.c')
| -rw-r--r-- | third_party/heimdal/lib/hdb/mkey.c | 769 |
1 files changed, 769 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/hdb/mkey.c b/third_party/heimdal/lib/hdb/mkey.c new file mode 100644 index 0000000..cfc27d4 --- /dev/null +++ b/third_party/heimdal/lib/hdb/mkey.c @@ -0,0 +1,769 @@ +/* + * Copyright (c) 2000 - 2004 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "hdb_locl.h" +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +struct hdb_master_key_data { + krb5_keytab_entry keytab; + krb5_crypto crypto; + struct hdb_master_key_data *next; + unsigned int key_usage; +}; + +void +hdb_free_master_key(krb5_context context, hdb_master_key mkey) +{ + struct hdb_master_key_data *ptr; + while(mkey) { + krb5_kt_free_entry(context, &mkey->keytab); + if (mkey->crypto) + krb5_crypto_destroy(context, mkey->crypto); + ptr = mkey; + mkey = mkey->next; + free(ptr); + } +} + +krb5_error_code +hdb_process_master_key(krb5_context context, + int kvno, krb5_keyblock *key, krb5_enctype etype, + hdb_master_key *mkey) +{ + krb5_error_code ret; + + *mkey = calloc(1, sizeof(**mkey)); + if(*mkey == NULL) { + krb5_set_error_message(context, ENOMEM, "malloc: out of memory"); + return ENOMEM; + } + (*mkey)->key_usage = HDB_KU_MKEY; + (*mkey)->keytab.vno = kvno; + ret = krb5_parse_name(context, "K/M", &(*mkey)->keytab.principal); + if(ret) + goto fail; + ret = krb5_copy_keyblock_contents(context, key, &(*mkey)->keytab.keyblock); + if(ret) + goto fail; + if(etype != 0) + (*mkey)->keytab.keyblock.keytype = etype; + (*mkey)->keytab.timestamp = time(NULL); + ret = krb5_crypto_init(context, key, etype, &(*mkey)->crypto); + if(ret) + goto fail; + return 0; + fail: + hdb_free_master_key(context, *mkey); + *mkey = NULL; + return ret; +} + +krb5_error_code +hdb_add_master_key(krb5_context context, krb5_keyblock *key, + hdb_master_key *inout) +{ + int vno = 0; + hdb_master_key p; + krb5_error_code ret; + + for(p = *inout; p; p = p->next) + vno = max(vno, p->keytab.vno); + vno++; + ret = hdb_process_master_key(context, vno, key, 0, &p); + if(ret) + return ret; + p->next = *inout; + *inout = p; + return 0; +} + +static krb5_error_code +read_master_keytab(krb5_context context, const char *filename, + hdb_master_key *mkey) +{ + krb5_error_code ret; + krb5_keytab id; + krb5_kt_cursor cursor; + krb5_keytab_entry entry; + hdb_master_key p; + + *mkey = NULL; + ret = krb5_kt_resolve(context, filename, &id); + if(ret) + return ret; + + ret = krb5_kt_start_seq_get(context, id, &cursor); + if(ret) + goto out; + while(krb5_kt_next_entry(context, id, &entry, &cursor) == 0) { + p = calloc(1, sizeof(*p)); + if (p == NULL) { + ret = ENOMEM; + break; + } + p->keytab = entry; + p->next = *mkey; + *mkey = p; + ret = krb5_crypto_init(context, &p->keytab.keyblock, 0, &p->crypto); + if (ret) + break; + } + krb5_kt_end_seq_get(context, id, &cursor); + out: + krb5_kt_close(context, id); + if (ret) { + hdb_free_master_key(context, *mkey); + *mkey = NULL; + } + return ret; +} + +/* read a MIT master keyfile */ +static krb5_error_code +read_master_mit(krb5_context context, const char *filename, + int byteorder, hdb_master_key *mkey) +{ + int fd; + krb5_error_code ret; + krb5_storage *sp; + int16_t enctype; + krb5_keyblock key; + + fd = open(filename, O_RDONLY | O_BINARY); + if(fd < 0) { + int save_errno = errno; + krb5_set_error_message(context, save_errno, "failed to open %s: %s", + filename, strerror(save_errno)); + return save_errno; + } + sp = krb5_storage_from_fd(fd); + if(sp == NULL) { + close(fd); + return errno; + } + krb5_storage_set_flags(sp, byteorder); + /* could possibly use ret_keyblock here, but do it with more + checks for now */ + { + ret = krb5_ret_int16(sp, &enctype); + if (ret) + goto out; + ret = krb5_enctype_valid(context, enctype); + if (ret) + goto out; + key.keytype = enctype; + ret = krb5_ret_data(sp, &key.keyvalue); + if(ret) + goto out; + } + ret = hdb_process_master_key(context, 1, &key, 0, mkey); + krb5_free_keyblock_contents(context, &key); + out: + krb5_storage_free(sp); + close(fd); + return ret; +} + +/* read an old master key file */ +static krb5_error_code +read_master_encryptionkey(krb5_context context, const char *filename, + hdb_master_key *mkey) +{ + int fd; + krb5_keyblock key; + krb5_error_code ret; + unsigned char buf[256]; + ssize_t len; + size_t ret_len; + + fd = open(filename, O_RDONLY | O_BINARY); + if(fd < 0) { + int save_errno = errno; + krb5_set_error_message(context, save_errno, "failed to open %s: %s", + filename, strerror(save_errno)); + return save_errno; + } + + len = read(fd, buf, sizeof(buf)); + close(fd); + if(len < 0) { + int save_errno = errno; + krb5_set_error_message(context, save_errno, "error reading %s: %s", + filename, strerror(save_errno)); + return save_errno; + } + + ret = decode_EncryptionKey(buf, len, &key, &ret_len); + memset_s(buf, sizeof(buf), 0, sizeof(buf)); + if(ret) + return ret; + + /* Originally, the keytype was just that, and later it got changed + to des-cbc-md5, but we always used des in cfb64 mode. This + should cover all cases, but will break if someone has hacked + this code to really use des-cbc-md5 -- but then that's not my + problem. */ + if(key.keytype == ETYPE_DES_CBC_CRC || key.keytype == ETYPE_DES_CBC_MD5) + key.keytype = ETYPE_DES_CFB64_NONE; + + ret = hdb_process_master_key(context, 0, &key, 0, mkey); + krb5_free_keyblock_contents(context, &key); + return ret; +} + +/* read a krb4 /.k style file */ +static krb5_error_code +read_master_krb4(krb5_context context, const char *filename, + hdb_master_key *mkey) +{ + int fd; + krb5_keyblock key; + krb5_error_code ret; + unsigned char buf[256]; + ssize_t len; + + fd = open(filename, O_RDONLY | O_BINARY); + if(fd < 0) { + int save_errno = errno; + krb5_set_error_message(context, save_errno, "failed to open %s: %s", + filename, strerror(save_errno)); + return save_errno; + } + + len = read(fd, buf, sizeof(buf)); + close(fd); + if(len < 0) { + int save_errno = errno; + krb5_set_error_message(context, save_errno, "error reading %s: %s", + filename, strerror(save_errno)); + return save_errno; + } + if(len != 8) { + krb5_set_error_message(context, HEIM_ERR_EOF, + "bad contents of %s", filename); + return HEIM_ERR_EOF; /* XXX file might be too large */ + } + + memset(&key, 0, sizeof(key)); + key.keytype = ETYPE_DES_PCBC_NONE; + ret = krb5_data_copy(&key.keyvalue, buf, len); + memset_s(buf, sizeof(buf), 0, sizeof(buf)); + if(ret) + return ret; + + ret = hdb_process_master_key(context, 0, &key, 0, mkey); + krb5_free_keyblock_contents(context, &key); + return ret; +} + +krb5_error_code +hdb_read_master_key(krb5_context context, const char *filename, + hdb_master_key *mkey) +{ + FILE *f; + unsigned char buf[16]; + krb5_error_code ret; + + off_t len; + + *mkey = NULL; + + if(filename == NULL) + filename = HDB_DB_DIR "/m-key"; + + f = fopen(filename, "r"); + if(f == NULL) { + int save_errno = errno; + krb5_set_error_message(context, save_errno, "failed to open %s: %s", + filename, strerror(save_errno)); + return save_errno; + } + + if(fread(buf, 1, 2, f) != 2) { + fclose(f); + krb5_set_error_message(context, HEIM_ERR_EOF, "end of file reading %s", filename); + return HEIM_ERR_EOF; + } + + fseek(f, 0, SEEK_END); + len = ftell(f); + + if(fclose(f) != 0) + return errno; + + if(len < 0) + return errno; + + if(len == 8) { + ret = read_master_krb4(context, filename, mkey); + } else if(buf[0] == 0x30 && len <= 127 && buf[1] == len - 2) { + ret = read_master_encryptionkey(context, filename, mkey); + } else if(buf[0] == 5 && buf[1] >= 1 && buf[1] <= 2) { + ret = read_master_keytab(context, filename, mkey); + } else { + /* + * Check both LittleEndian and BigEndian since they key file + * might be moved from a machine with diffrent byte order, or + * its running on MacOS X that always uses BE master keys. + */ + ret = read_master_mit(context, filename, KRB5_STORAGE_BYTEORDER_LE, mkey); + if (ret) + ret = read_master_mit(context, filename, KRB5_STORAGE_BYTEORDER_BE, mkey); + } + return ret; +} + +krb5_error_code +hdb_write_master_key(krb5_context context, const char *filename, + hdb_master_key mkey) +{ + krb5_error_code ret; + hdb_master_key p; + krb5_keytab kt; + + if(filename == NULL) + filename = HDB_DB_DIR "/m-key"; + + ret = krb5_kt_resolve(context, filename, &kt); + if(ret) + return ret; + + for(p = mkey; p; p = p->next) { + ret = krb5_kt_add_entry(context, kt, &p->keytab); + } + + krb5_kt_close(context, kt); + + return ret; +} + +krb5_error_code +_hdb_set_master_key_usage(krb5_context context, HDB *db, unsigned int key_usage) +{ + if (db->hdb_master_key_set == 0) + return HDB_ERR_NO_MKEY; + db->hdb_master_key->key_usage = key_usage; + return 0; +} + +hdb_master_key +_hdb_find_master_key(unsigned int *mkvno, hdb_master_key mkey) +{ + hdb_master_key ret = NULL; + while(mkey) { + if(ret == NULL && mkey->keytab.vno == 0) + ret = mkey; + if(mkvno == NULL) { + if(ret == NULL || mkey->keytab.vno > ret->keytab.vno) + ret = mkey; + } else if((uint32_t)mkey->keytab.vno == *mkvno) + return mkey; + mkey = mkey->next; + } + return ret; +} + +int +_hdb_mkey_version(hdb_master_key mkey) +{ + return mkey->keytab.vno; +} + +int +_hdb_mkey_decrypt(krb5_context context, hdb_master_key key, + krb5_key_usage usage, + void *ptr, size_t size, krb5_data *res) +{ + return krb5_decrypt(context, key->crypto, usage, + ptr, size, res); +} + +int +_hdb_mkey_encrypt(krb5_context context, hdb_master_key key, + krb5_key_usage usage, + const void *ptr, size_t size, krb5_data *res) +{ + return krb5_encrypt(context, key->crypto, usage, + ptr, size, res); +} + +krb5_error_code +hdb_unseal_key_mkey(krb5_context context, Key *k, hdb_master_key mkey) +{ + + krb5_error_code ret; + krb5_data res; + size_t keysize; + + hdb_master_key key; + + if(k->mkvno == NULL) + return 0; + + key = _hdb_find_master_key(k->mkvno, mkey); + + if (key == NULL) + return HDB_ERR_NO_MKEY; + + ret = _hdb_mkey_decrypt(context, key, HDB_KU_MKEY, + k->key.keyvalue.data, + k->key.keyvalue.length, + &res); + if(ret == KRB5KRB_AP_ERR_BAD_INTEGRITY) { + /* try to decrypt with MIT key usage */ + ret = _hdb_mkey_decrypt(context, key, 0, + k->key.keyvalue.data, + k->key.keyvalue.length, + &res); + } + if (ret) + return ret; + + /* fixup keylength if the key got padded when encrypting it */ + ret = krb5_enctype_keysize(context, k->key.keytype, &keysize); + if (ret) { + krb5_data_free(&res); + return ret; + } + if (keysize > res.length) { + krb5_data_free(&res); + return KRB5_BAD_KEYSIZE; + } + + memset(k->key.keyvalue.data, 0, k->key.keyvalue.length); + free(k->key.keyvalue.data); + k->key.keyvalue = res; + k->key.keyvalue.length = keysize; + free(k->mkvno); + k->mkvno = NULL; + + return 0; +} + +krb5_error_code +hdb_unseal_keys_mkey(krb5_context context, hdb_entry *ent, hdb_master_key mkey) +{ + size_t i; + + for(i = 0; i < ent->keys.len; i++){ + krb5_error_code ret; + + ret = hdb_unseal_key_mkey(context, &ent->keys.val[i], mkey); + if (ret) + return ret; + } + return 0; +} + +krb5_error_code +hdb_unseal_keys(krb5_context context, HDB *db, hdb_entry *ent) +{ + if (db->hdb_master_key_set == 0) + return 0; + return hdb_unseal_keys_mkey(context, ent, db->hdb_master_key); +} + +/* + * Unseal the keys for the given kvno (or all of them) of entry. + * + * If kvno == 0 -> unseal all. + * if kvno != 0 -> unseal the requested kvno and make sure it's the one listed + * as the current keyset for the entry (swapping it with a + * historical keyset if need be). + */ +krb5_error_code +hdb_unseal_keys_kvno(krb5_context context, HDB *db, krb5_kvno kvno, + unsigned flags, hdb_entry *ent) +{ + krb5_error_code ret = HDB_ERR_NOENTRY; + HDB_extension *ext; + HDB_Ext_KeySet *hist_keys; + Key *tmp_val; + time_t tmp_set_time; + unsigned int tmp_len; + unsigned int kvno_diff = 0; + krb5_kvno tmp_kvno; + size_t i, k; + int exclude_dead = 0; + KerberosTime now = 0; + + if (kvno == 0) + ret = 0; + + if ((flags & HDB_F_LIVE_CLNT_KVNOS) || (flags & HDB_F_LIVE_SVC_KVNOS)) { + exclude_dead = 1; + now = time(NULL); + if (HDB_F_LIVE_CLNT_KVNOS) + kvno_diff = hdb_entry_get_kvno_diff_clnt(ent); + else + kvno_diff = hdb_entry_get_kvno_diff_svc(ent); + } + + ext = hdb_find_extension(ent, choice_HDB_extension_data_hist_keys); + if (ext == NULL || (&ext->data.u.hist_keys)->len == 0) + return hdb_unseal_keys_mkey(context, ent, db->hdb_master_key); + + /* For swapping; see below */ + tmp_len = ent->keys.len; + tmp_val = ent->keys.val; + tmp_kvno = ent->kvno; + (void) hdb_entry_get_pw_change_time(ent, &tmp_set_time); + + hist_keys = &ext->data.u.hist_keys; + + for (i = 0; i < hist_keys->len; i++) { + if (kvno != 0 && hist_keys->val[i].kvno != kvno) + continue; + + if (exclude_dead && + ((ent->max_life != NULL && + hist_keys->val[i].set_time != NULL && + (*hist_keys->val[i].set_time) < (now - (*ent->max_life))) || + (hist_keys->val[i].kvno < kvno && + (kvno - hist_keys->val[i].kvno) > kvno_diff))) + /* + * The KDC may want to to check for this keyset's set_time + * is within the TGS principal's max_life, say. But we stop + * here. + */ + continue; + + /* Either the keys we want, or all the keys */ + for (k = 0; k < hist_keys->val[i].keys.len; k++) { + ret = hdb_unseal_key_mkey(context, + &hist_keys->val[i].keys.val[k], + db->hdb_master_key); + /* + * If kvno == 0 we might not want to bail here! E.g., if we + * no longer have the right master key, so just ignore this. + * + * We could filter out keys that we can't decrypt here + * because of HDB_ERR_NO_MKEY. However, it seems safest to + * filter them out only where necessary, say, in kadm5. + */ + if (ret && kvno != 0) + return ret; + if (ret && ret != HDB_ERR_NO_MKEY) + return (ret); + } + + if (kvno == 0) + continue; + + /* + * What follows is a bit of a hack. + * + * This is the keyset we're being asked for, but it's not the + * current keyset. So we add the current keyset to the history, + * leave the one we were asked for in the history, and pretend + * the one we were asked for is also the current keyset. + * + * This is a bit of a defensive hack in case an entry fetched + * this way ever gets modified then stored: if the keyset is not + * changed we can detect this and put things back, else we won't + * drop any keysets from history by accident. + * + * Note too that we only ever get called with a non-zero kvno + * either in the KDC or in cases where we aren't changing the + * HDB entry anyways, which is why this is just a defensive + * hack. We also don't fetch specific kvnos in the dump case, + * so there's no danger that we'll dump this entry and load it + * again, repeatedly causing the history to grow boundelessly. + */ + + /* Swap key sets */ + ent->kvno = hist_keys->val[i].kvno; + ent->keys.val = hist_keys->val[i].keys.val; + ent->keys.len = hist_keys->val[i].keys.len; + if (hist_keys->val[i].set_time != NULL) + /* Sloppy, but the callers we expect won't care */ + (void) hdb_entry_set_pw_change_time(context, ent, + *hist_keys->val[i].set_time); + hist_keys->val[i].kvno = tmp_kvno; + hist_keys->val[i].keys.val = tmp_val; + hist_keys->val[i].keys.len = tmp_len; + if (hist_keys->val[i].set_time != NULL) + /* Sloppy, but the callers we expect won't care */ + *hist_keys->val[i].set_time = tmp_set_time; + + return 0; + } + + return (ret); +} + +krb5_error_code +hdb_unseal_key(krb5_context context, HDB *db, Key *k) +{ + if (db->hdb_master_key_set == 0) + return 0; + return hdb_unseal_key_mkey(context, k, db->hdb_master_key); +} + +krb5_error_code +hdb_seal_key_mkey(krb5_context context, Key *k, hdb_master_key mkey) +{ + krb5_error_code ret; + krb5_data res; + hdb_master_key key; + + if(k->mkvno != NULL) + return 0; + + key = _hdb_find_master_key(k->mkvno, mkey); + + if (key == NULL) + return HDB_ERR_NO_MKEY; + + ret = _hdb_mkey_encrypt(context, key, HDB_KU_MKEY, + k->key.keyvalue.data, + k->key.keyvalue.length, + &res); + if (ret) + return ret; + + memset(k->key.keyvalue.data, 0, k->key.keyvalue.length); + free(k->key.keyvalue.data); + k->key.keyvalue = res; + + if (k->mkvno == NULL) { + k->mkvno = malloc(sizeof(*k->mkvno)); + if (k->mkvno == NULL) + return ENOMEM; + } + *k->mkvno = key->keytab.vno; + + return 0; +} + +krb5_error_code +hdb_seal_keys_mkey(krb5_context context, hdb_entry *ent, hdb_master_key mkey) +{ + HDB_extension *ext; + HDB_Ext_KeySet *hist_keys; + size_t i, k; + krb5_error_code ret; + + for(i = 0; i < ent->keys.len; i++){ + ret = hdb_seal_key_mkey(context, &ent->keys.val[i], mkey); + if (ret) + return ret; + } + + ext = hdb_find_extension(ent, choice_HDB_extension_data_hist_keys); + if (ext == NULL) + return 0; + hist_keys = &ext->data.u.hist_keys; + + for (i = 0; i < hist_keys->len; i++) { + for (k = 0; k < hist_keys->val[i].keys.len; k++) { + ret = hdb_seal_key_mkey(context, &hist_keys->val[i].keys.val[k], + mkey); + if (ret) + return ret; + } + } + + return 0; +} + +krb5_error_code +hdb_seal_keys(krb5_context context, HDB *db, hdb_entry *ent) +{ + if (db->hdb_master_key_set == 0) + return 0; + + return hdb_seal_keys_mkey(context, ent, db->hdb_master_key); +} + +krb5_error_code +hdb_seal_key(krb5_context context, HDB *db, Key *k) +{ + if (db->hdb_master_key_set == 0) + return 0; + + return hdb_seal_key_mkey(context, k, db->hdb_master_key); +} + +krb5_error_code +hdb_set_master_key(krb5_context context, + HDB *db, + krb5_keyblock *key) +{ + krb5_error_code ret; + hdb_master_key mkey; + + ret = hdb_process_master_key(context, 0, key, 0, &mkey); + if (ret) + return ret; + db->hdb_master_key = mkey; +#if 0 /* XXX - why? */ + des_set_random_generator_seed(key.keyvalue.data); +#endif + db->hdb_master_key_set = 1; + db->hdb_master_key->key_usage = HDB_KU_MKEY; + return 0; +} + +krb5_error_code +hdb_set_master_keyfile (krb5_context context, + HDB *db, + const char *keyfile) +{ + hdb_master_key key; + krb5_error_code ret; + + ret = hdb_read_master_key(context, keyfile, &key); + if (ret) { + if (ret != ENOENT) + return ret; + krb5_clear_error_message(context); + return 0; + } + db->hdb_master_key = key; + db->hdb_master_key_set = 1; + return ret; +} + +krb5_error_code +hdb_clear_master_key (krb5_context context, + HDB *db) +{ + if (db->hdb_master_key_set) { + hdb_free_master_key(context, db->hdb_master_key); + db->hdb_master_key_set = 0; + } + return 0; +} |