diff options
Diffstat (limited to 'source4/heimdal/lib/krb5/fcache.c')
| -rw-r--r-- | source4/heimdal/lib/krb5/fcache.c | 718 |
1 files changed, 718 insertions, 0 deletions
diff --git a/source4/heimdal/lib/krb5/fcache.c b/source4/heimdal/lib/krb5/fcache.c new file mode 100644 index 0000000000..03848abb9a --- /dev/null +++ b/source4/heimdal/lib/krb5/fcache.c @@ -0,0 +1,718 @@ +/* + * Copyright (c) 1997 - 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 "krb5_locl.h" + +RCSID("$Id: fcache.c,v 1.49 2005/06/16 20:25:20 lha Exp $"); + +typedef struct krb5_fcache{ + char *filename; + int version; +}krb5_fcache; + +struct fcc_cursor { + int fd; + krb5_storage *sp; +}; + +#define KRB5_FCC_FVNO_1 1 +#define KRB5_FCC_FVNO_2 2 +#define KRB5_FCC_FVNO_3 3 +#define KRB5_FCC_FVNO_4 4 + +#define FCC_TAG_DELTATIME 1 + +#define FCACHE(X) ((krb5_fcache*)(X)->data.data) + +#define FILENAME(X) (FCACHE(X)->filename) + +#define FCC_CURSOR(C) ((struct fcc_cursor*)(C)) + +static const char* +fcc_get_name(krb5_context context, + krb5_ccache id) +{ + return FILENAME(id); +} + +int +_krb5_xlock(krb5_context context, int fd, krb5_boolean exclusive, + const char *filename) +{ + int ret; +#ifdef HAVE_FCNTL + struct flock l; + + l.l_start = 0; + l.l_len = 0; + l.l_type = exclusive ? F_WRLCK : F_RDLCK; + l.l_whence = SEEK_SET; + ret = fcntl(fd, F_SETLKW, &l); +#else + ret = flock(fd, exclusive ? LOCK_EX : LOCK_SH); +#endif + if(ret < 0) + ret = errno; + if(ret == EACCES) /* fcntl can return EACCES instead of EAGAIN */ + ret = EAGAIN; + + switch (ret) { + case 0: + break; + case EINVAL: /* filesystem doesn't support locking, let the user have it */ + ret = 0; + break; + case EAGAIN: + krb5_set_error_string(context, "timed out locking cache file %s", + filename); + break; + default: + krb5_set_error_string(context, "error locking cache file %s: %s", + filename, strerror(ret)); + break; + } + return ret; +} + +int +_krb5_xunlock(krb5_context context, int fd) +{ + int ret; +#ifdef HAVE_FCNTL_LOCK + struct flock l; + l.l_start = 0; + l.l_len = 0; + l.l_type = F_UNLCK; + l.l_whence = SEEK_SET; + ret = fcntl(fd, F_SETLKW, &l); +#else + ret = flock(fd, LOCK_UN); +#endif + if (ret < 0) + ret = errno; + switch (ret) { + case 0: + break; + case EINVAL: /* filesystem doesn't support locking, let the user have it */ + ret = 0; + break; + default: + krb5_set_error_string(context, + "Failed to unlock file: %s", strerror(ret)); + break; + } + return ret; +} + +static krb5_error_code +fcc_lock(krb5_context context, krb5_ccache id, + int fd, krb5_boolean exclusive) +{ + return _krb5_xlock(context, fd, exclusive, fcc_get_name(context, id)); +} + +static krb5_error_code +fcc_unlock(krb5_context context, int fd) +{ + return _krb5_xunlock(context, fd); +} + +static krb5_error_code +fcc_resolve(krb5_context context, krb5_ccache *id, const char *res) +{ + krb5_fcache *f; + f = malloc(sizeof(*f)); + if(f == NULL) { + krb5_set_error_string(context, "malloc: out of memory"); + return KRB5_CC_NOMEM; + } + f->filename = strdup(res); + if(f->filename == NULL){ + free(f); + krb5_set_error_string(context, "malloc: out of memory"); + return KRB5_CC_NOMEM; + } + f->version = 0; + (*id)->data.data = f; + (*id)->data.length = sizeof(*f); + return 0; +} + +/* + * Try to scrub the contents of `filename' safely. + */ + +static int +scrub_file (int fd) +{ + off_t pos; + char buf[128]; + + pos = lseek(fd, 0, SEEK_END); + if (pos < 0) + return errno; + if (lseek(fd, 0, SEEK_SET) < 0) + return errno; + memset(buf, 0, sizeof(buf)); + while(pos > 0) { + ssize_t tmp = write(fd, buf, min(sizeof(buf), pos)); + + if (tmp < 0) + return errno; + pos -= tmp; + } + fsync (fd); + return 0; +} + +/* + * Erase `filename' if it exists, trying to remove the contents if + * it's `safe'. We always try to remove the file, it it exists. It's + * only overwritten if it's a regular file (not a symlink and not a + * hardlink) + */ + +static krb5_error_code +erase_file(const char *filename) +{ + int fd; + struct stat sb1, sb2; + int ret; + + ret = lstat (filename, &sb1); + if (ret < 0) + return errno; + + fd = open(filename, O_RDWR | O_BINARY); + if(fd < 0) { + if(errno == ENOENT) + return 0; + else + return errno; + } + if (unlink(filename) < 0) { + close (fd); + return errno; + } + ret = fstat (fd, &sb2); + if (ret < 0) { + close (fd); + return errno; + } + + /* check if someone was playing with symlinks */ + + if (sb1.st_dev != sb2.st_dev || sb1.st_ino != sb2.st_ino) { + close (fd); + return EPERM; + } + + /* there are still hard links to this file */ + + if (sb2.st_nlink != 0) { + close (fd); + return 0; + } + + ret = scrub_file (fd); + close (fd); + return ret; +} + +static krb5_error_code +fcc_gen_new(krb5_context context, krb5_ccache *id) +{ + krb5_fcache *f; + int fd; + char *file; + + f = malloc(sizeof(*f)); + if(f == NULL) { + krb5_set_error_string(context, "malloc: out of memory"); + return KRB5_CC_NOMEM; + } + asprintf (&file, "%sXXXXXX", KRB5_DEFAULT_CCFILE_ROOT); + if(file == NULL) { + free(f); + krb5_set_error_string(context, "malloc: out of memory"); + return KRB5_CC_NOMEM; + } + fd = mkstemp(file); + if(fd < 0) { + free(f); + free(file); + krb5_set_error_string(context, "mkstemp %s", file); + return errno; + } + close(fd); + f->filename = file; + f->version = 0; + (*id)->data.data = f; + (*id)->data.length = sizeof(*f); + return 0; +} + +static void +storage_set_flags(krb5_context context, krb5_storage *sp, int vno) +{ + int flags = 0; + switch(vno) { + case KRB5_FCC_FVNO_1: + flags |= KRB5_STORAGE_PRINCIPAL_WRONG_NUM_COMPONENTS; + flags |= KRB5_STORAGE_PRINCIPAL_NO_NAME_TYPE; + flags |= KRB5_STORAGE_HOST_BYTEORDER; + break; + case KRB5_FCC_FVNO_2: + flags |= KRB5_STORAGE_HOST_BYTEORDER; + break; + case KRB5_FCC_FVNO_3: + flags |= KRB5_STORAGE_KEYBLOCK_KEYTYPE_TWICE; + break; + case KRB5_FCC_FVNO_4: + break; + default: + krb5_abortx(context, + "storage_set_flags called with bad vno (%x)", vno); + } + krb5_storage_set_flags(sp, flags); +} + +static krb5_error_code +fcc_open(krb5_context context, + krb5_ccache id, + int *fd_ret, + int flags, + mode_t mode) +{ + krb5_boolean exclusive = ((flags | O_WRONLY) == flags || + (flags | O_RDWR) == flags); + krb5_error_code ret; + const char *filename = FILENAME(id); + int fd; + fd = open(filename, flags, mode); + if(fd < 0) { + ret = errno; + krb5_set_error_string(context, "open(%s): %s", filename, + strerror(ret)); + return ret; + } + + if((ret = fcc_lock(context, id, fd, exclusive)) != 0) { + close(fd); + return ret; + } + *fd_ret = fd; + return 0; +} + +static krb5_error_code +fcc_initialize(krb5_context context, + krb5_ccache id, + krb5_principal primary_principal) +{ + krb5_fcache *f = FCACHE(id); + int ret = 0; + int fd; + char *filename = f->filename; + + unlink (filename); + + ret = fcc_open(context, id, &fd, O_RDWR | O_CREAT | O_EXCL | O_BINARY, 0600); + if(ret) + return ret; + { + krb5_storage *sp; + sp = krb5_storage_from_fd(fd); + krb5_storage_set_eof_code(sp, KRB5_CC_END); + if(context->fcache_vno != 0) + f->version = context->fcache_vno; + else + f->version = KRB5_FCC_FVNO_4; + ret |= krb5_store_int8(sp, 5); + ret |= krb5_store_int8(sp, f->version); + storage_set_flags(context, sp, f->version); + if(f->version == KRB5_FCC_FVNO_4 && ret == 0) { + /* V4 stuff */ + if (context->kdc_sec_offset) { + ret |= krb5_store_int16 (sp, 12); /* length */ + ret |= krb5_store_int16 (sp, FCC_TAG_DELTATIME); /* Tag */ + ret |= krb5_store_int16 (sp, 8); /* length of data */ + ret |= krb5_store_int32 (sp, context->kdc_sec_offset); + ret |= krb5_store_int32 (sp, context->kdc_usec_offset); + } else { + ret |= krb5_store_int16 (sp, 0); + } + } + ret |= krb5_store_principal(sp, primary_principal); + + krb5_storage_free(sp); + } + fcc_unlock(context, fd); + if (close(fd) < 0) + if (ret == 0) { + ret = errno; + krb5_set_error_string (context, "close %s: %s", + FILENAME(id), strerror(ret)); + } + return ret; +} + +static krb5_error_code +fcc_close(krb5_context context, + krb5_ccache id) +{ + free (FILENAME(id)); + krb5_data_free(&id->data); + return 0; +} + +static krb5_error_code +fcc_destroy(krb5_context context, + krb5_ccache id) +{ + erase_file(FILENAME(id)); + return 0; +} + +static krb5_error_code +fcc_store_cred(krb5_context context, + krb5_ccache id, + krb5_creds *creds) +{ + int ret; + int fd; + + ret = fcc_open(context, id, &fd, O_WRONLY | O_APPEND | O_BINARY, 0); + if(ret) + return ret; + { + krb5_storage *sp; + sp = krb5_storage_from_fd(fd); + krb5_storage_set_eof_code(sp, KRB5_CC_END); + storage_set_flags(context, sp, FCACHE(id)->version); + if (!krb5_config_get_bool_default(context, NULL, TRUE, + "libdefaults", + "fcc-mit-ticketflags", + NULL)) + krb5_storage_set_flags(sp, KRB5_STORAGE_CREDS_FLAGS_WRONG_BITORDER); + ret = krb5_store_creds(sp, creds); + krb5_storage_free(sp); + } + fcc_unlock(context, fd); + if (close(fd) < 0) + if (ret == 0) { + ret = errno; + krb5_set_error_string (context, "close %s: %s", + FILENAME(id), strerror(ret)); + } + return ret; +} + +static krb5_error_code +init_fcc (krb5_context context, + krb5_ccache id, + krb5_storage **ret_sp, + int *ret_fd) +{ + int fd; + int8_t pvno, tag; + krb5_storage *sp; + krb5_error_code ret; + + ret = fcc_open(context, id, &fd, O_RDONLY | O_BINARY, 0); + if(ret) + return ret; + + sp = krb5_storage_from_fd(fd); + if(sp == NULL) { + krb5_clear_error_string(context); + ret = ENOMEM; + goto out; + } + krb5_storage_set_eof_code(sp, KRB5_CC_END); + ret = krb5_ret_int8(sp, &pvno); + if(ret != 0) { + if(ret == KRB5_CC_END) + ret = ENOENT; /* empty file */ + krb5_clear_error_string(context); + goto out; + } + if(pvno != 5) { + krb5_set_error_string(context, "Bad version number in credential " + "cache file: %s", FILENAME(id)); + ret = KRB5_CCACHE_BADVNO; + goto out; + } + ret = krb5_ret_int8(sp, &tag); /* should not be host byte order */ + if(ret != 0) { + krb5_clear_error_string(context); + ret = KRB5_CC_FORMAT; + goto out; + } + FCACHE(id)->version = tag; + storage_set_flags(context, sp, FCACHE(id)->version); + switch (tag) { + case KRB5_FCC_FVNO_4: { + int16_t length; + + ret = krb5_ret_int16 (sp, &length); + if(ret) { + ret = KRB5_CC_FORMAT; + krb5_clear_error_string(context); + goto out; + } + while(length > 0) { + int16_t dtag, data_len; + int i; + int8_t dummy; + + ret = krb5_ret_int16 (sp, &dtag); + if(ret) { + krb5_clear_error_string(context); + ret = KRB5_CC_FORMAT; + goto out; + } + ret = krb5_ret_int16 (sp, &data_len); + if(ret) { + krb5_clear_error_string(context); + ret = KRB5_CC_FORMAT; + goto out; + } + switch (dtag) { + case FCC_TAG_DELTATIME : + ret = krb5_ret_int32 (sp, &context->kdc_sec_offset); + if(ret) { + krb5_clear_error_string(context); + ret = KRB5_CC_FORMAT; + goto out; + } + ret = krb5_ret_int32 (sp, &context->kdc_usec_offset); + if(ret) { + krb5_clear_error_string(context); + ret = KRB5_CC_FORMAT; + goto out; + } + break; + default : + for (i = 0; i < data_len; ++i) { + ret = krb5_ret_int8 (sp, &dummy); + if(ret) { + krb5_clear_error_string(context); + ret = KRB5_CC_FORMAT; + goto out; + } + } + break; + } + length -= 4 + data_len; + } + break; + } + case KRB5_FCC_FVNO_3: + case KRB5_FCC_FVNO_2: + case KRB5_FCC_FVNO_1: + break; + default : + ret = KRB5_CCACHE_BADVNO; + krb5_set_error_string(context, "Unknown version number (%d) in " + "credential cache file: %s", + (int)tag, FILENAME(id)); + goto out; + } + *ret_sp = sp; + *ret_fd = fd; + + return 0; + out: + if(sp != NULL) + krb5_storage_free(sp); + fcc_unlock(context, fd); + close(fd); + return ret; +} + +static krb5_error_code +fcc_get_principal(krb5_context context, + krb5_ccache id, + krb5_principal *principal) +{ + krb5_error_code ret; + int fd; + krb5_storage *sp; + + ret = init_fcc (context, id, &sp, &fd); + if (ret) + return ret; + ret = krb5_ret_principal(sp, principal); + if (ret) + krb5_clear_error_string(context); + krb5_storage_free(sp); + fcc_unlock(context, fd); + close(fd); + return ret; +} + +static krb5_error_code +fcc_end_get (krb5_context context, + krb5_ccache id, + krb5_cc_cursor *cursor); + +static krb5_error_code +fcc_get_first (krb5_context context, + krb5_ccache id, + krb5_cc_cursor *cursor) +{ + krb5_error_code ret; + krb5_principal principal; + + *cursor = malloc(sizeof(struct fcc_cursor)); + if (*cursor == NULL) { + krb5_set_error_string (context, "malloc: out of memory"); + return ENOMEM; + } + memset(*cursor, 0, sizeof(struct fcc_cursor)); + + ret = init_fcc (context, id, &FCC_CURSOR(*cursor)->sp, + &FCC_CURSOR(*cursor)->fd); + if (ret) { + free(*cursor); + *cursor = NULL; + return ret; + } + ret = krb5_ret_principal (FCC_CURSOR(*cursor)->sp, &principal); + if(ret) { + krb5_clear_error_string(context); + fcc_end_get(context, id, cursor); + return ret; + } + krb5_free_principal (context, principal); + fcc_unlock(context, FCC_CURSOR(*cursor)->fd); + return 0; +} + +static krb5_error_code +fcc_get_next (krb5_context context, + krb5_ccache id, + krb5_cc_cursor *cursor, + krb5_creds *creds) +{ + krb5_error_code ret; + if((ret = fcc_lock(context, id, FCC_CURSOR(*cursor)->fd, FALSE)) != 0) + return ret; + + ret = krb5_ret_creds(FCC_CURSOR(*cursor)->sp, creds); + if (ret) + krb5_clear_error_string(context); + + fcc_unlock(context, FCC_CURSOR(*cursor)->fd); + return ret; +} + +static krb5_error_code +fcc_end_get (krb5_context context, + krb5_ccache id, + krb5_cc_cursor *cursor) +{ + krb5_storage_free(FCC_CURSOR(*cursor)->sp); + close (FCC_CURSOR(*cursor)->fd); + free(*cursor); + *cursor = NULL; + return 0; +} + +static krb5_error_code +fcc_remove_cred(krb5_context context, + krb5_ccache id, + krb5_flags which, + krb5_creds *cred) +{ + krb5_error_code ret; + krb5_ccache copy; + + ret = krb5_cc_gen_new(context, &krb5_mcc_ops, ©); + if (ret) + return ret; + + ret = krb5_cc_copy_cache(context, id, copy); + if (ret) { + krb5_cc_destroy(context, copy); + return ret; + } + + ret = krb5_cc_remove_cred(context, copy, which, cred); + if (ret) { + krb5_cc_destroy(context, copy); + return ret; + } + + fcc_destroy(context, id); + + ret = krb5_cc_copy_cache(context, copy, id); + krb5_cc_destroy(context, copy); + + return ret; +} + +static krb5_error_code +fcc_set_flags(krb5_context context, + krb5_ccache id, + krb5_flags flags) +{ + return 0; /* XXX */ +} + +static krb5_error_code +fcc_get_version(krb5_context context, + krb5_ccache id) +{ + return FCACHE(id)->version; +} + +const krb5_cc_ops krb5_fcc_ops = { + "FILE", + fcc_get_name, + fcc_resolve, + fcc_gen_new, + fcc_initialize, + fcc_destroy, + fcc_close, + fcc_store_cred, + NULL, /* fcc_retrieve */ + fcc_get_principal, + fcc_get_first, + fcc_get_next, + fcc_end_get, + fcc_remove_cred, + fcc_set_flags, + fcc_get_version +}; |