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/*
* Authentication certificate routines for the CUPS scheduler.
*
* Copyright 2007-2016 by Apple Inc.
* Copyright 1997-2006 by Easy Software Products.
*
* Licensed under Apache License v2.0. See the file "LICENSE" for more information.
*/
/*
* Include necessary headers...
*/
#include "cupsd.h"
#ifdef HAVE_ACL_INIT
# include <sys/acl.h>
# ifdef HAVE_MEMBERSHIP_H
# include <membership.h>
# endif /* HAVE_MEMBERSHIP_H */
#endif /* HAVE_ACL_INIT */
/*
* Local functions...
*/
static int ctcompare(const char *a, const char *b);
/*
* 'cupsdAddCert()' - Add a certificate.
*/
void
cupsdAddCert(int pid, /* I - Process ID */
const char *username, /* I - Username */
int type) /* I - AuthType for username */
{
int i; /* Looping var */
cupsd_cert_t *cert; /* Current certificate */
int fd; /* Certificate file */
char filename[1024]; /* Certificate filename */
static const char hex[] = "0123456789ABCDEF";
/* Hex constants... */
cupsdLogMessage(CUPSD_LOG_DEBUG, "cupsdAddCert: Adding certificate for PID %d", pid);
/*
* Allocate memory for the certificate...
*/
if ((cert = calloc(sizeof(cupsd_cert_t), 1)) == NULL)
return;
/*
* Fill in the certificate information...
*/
cert->pid = pid;
cert->type = type;
strlcpy(cert->username, username, sizeof(cert->username));
for (i = 0; i < 32; i ++)
cert->certificate[i] = hex[CUPS_RAND() & 15];
/*
* Save the certificate to a file readable only by the User and Group
* (or root and SystemGroup for PID == 0)...
*/
snprintf(filename, sizeof(filename), "%s/certs/%d", StateDir, pid);
unlink(filename);
if ((fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400)) < 0)
{
cupsdLogMessage(CUPSD_LOG_ERROR,
"Unable to create certificate file %s - %s",
filename, strerror(errno));
free(cert);
return;
}
if (pid == 0)
{
#ifdef HAVE_ACL_INIT
acl_t acl; /* ACL information */
acl_entry_t entry; /* ACL entry */
acl_permset_t permset; /* Permissions */
# ifdef HAVE_MBR_UID_TO_UUID
uuid_t group; /* Group ID */
# endif /* HAVE_MBR_UID_TO_UUID */
static int acls_not_supported = 0;
/* Only warn once */
#endif /* HAVE_ACL_INIT */
/*
* Root certificate...
*/
fchmod(fd, 0440);
fchown(fd, RunUser, SystemGroupIDs[0]);
cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdAddCert: NumSystemGroups=%d", NumSystemGroups);
#ifdef HAVE_ACL_INIT
if (NumSystemGroups > 1)
{
/*
* Set POSIX ACLs for the root certificate so that all system
* groups can access it...
*/
int j; /* Looping var */
# ifdef HAVE_MBR_UID_TO_UUID
/*
* On macOS, ACLs use UUIDs instead of GIDs...
*/
acl = acl_init(NumSystemGroups - 1);
for (i = 1; i < NumSystemGroups; i ++)
{
/*
* Add each group ID to the ACL...
*/
for (j = 0; j < i; j ++)
if (SystemGroupIDs[j] == SystemGroupIDs[i])
break;
if (j < i)
continue; /* Skip duplicate groups */
acl_create_entry(&acl, &entry);
acl_get_permset(entry, &permset);
acl_add_perm(permset, ACL_READ_DATA);
acl_set_tag_type(entry, ACL_EXTENDED_ALLOW);
mbr_gid_to_uuid((gid_t)SystemGroupIDs[i], group);
acl_set_qualifier(entry, &group);
acl_set_permset(entry, permset);
}
# else
/*
* POSIX ACLs need permissions for owner, group, other, and mask
* in addition to the rest of the system groups...
*/
acl = acl_init(NumSystemGroups + 3);
/* Owner */
acl_create_entry(&acl, &entry);
acl_get_permset(entry, &permset);
acl_add_perm(permset, ACL_READ);
acl_set_tag_type(entry, ACL_USER_OBJ);
acl_set_permset(entry, permset);
/* Group */
acl_create_entry(&acl, &entry);
acl_get_permset(entry, &permset);
acl_add_perm(permset, ACL_READ);
acl_set_tag_type(entry, ACL_GROUP_OBJ);
acl_set_permset(entry, permset);
/* Others */
acl_create_entry(&acl, &entry);
acl_get_permset(entry, &permset);
acl_add_perm(permset, 0);
acl_set_tag_type(entry, ACL_OTHER);
acl_set_permset(entry, permset);
/* Mask */
acl_create_entry(&acl, &entry);
acl_get_permset(entry, &permset);
acl_add_perm(permset, ACL_READ);
acl_set_tag_type(entry, ACL_MASK);
acl_set_permset(entry, permset);
for (i = 1; i < NumSystemGroups; i ++)
{
/*
* Add each group ID to the ACL...
*/
for (j = 0; j < i; j ++)
if (SystemGroupIDs[j] == SystemGroupIDs[i])
break;
if (j < i)
continue; /* Skip duplicate groups */
acl_create_entry(&acl, &entry);
acl_get_permset(entry, &permset);
acl_add_perm(permset, ACL_READ);
acl_set_tag_type(entry, ACL_GROUP);
acl_set_qualifier(entry, SystemGroupIDs + i);
acl_set_permset(entry, permset);
}
if (acl_valid(acl))
{
char *text, *textptr; /* Temporary string */
cupsdLogMessage(CUPSD_LOG_ERROR, "ACL did not validate: %s",
strerror(errno));
text = acl_to_text(acl, NULL);
for (textptr = strchr(text, '\n');
textptr;
textptr = strchr(textptr + 1, '\n'))
*textptr = ',';
cupsdLogMessage(CUPSD_LOG_ERROR, "ACL: %s", text);
acl_free(text);
}
# endif /* HAVE_MBR_UID_TO_UUID */
if (acl_set_fd(fd, acl))
{
if (errno != EOPNOTSUPP || !acls_not_supported)
cupsdLogMessage(CUPSD_LOG_ERROR,
"Unable to set ACLs on root certificate \"%s\" - %s",
filename, strerror(errno));
if (errno == EOPNOTSUPP)
acls_not_supported = 1;
}
acl_free(acl);
}
#endif /* HAVE_ACL_INIT */
RootCertTime = time(NULL);
}
else
{
/*
* CGI certificate...
*/
fchmod(fd, 0400);
fchown(fd, User, Group);
}
write(fd, cert->certificate, strlen(cert->certificate));
close(fd);
/*
* Insert the certificate at the front of the list...
*/
cert->next = Certs;
Certs = cert;
}
/*
* 'cupsdDeleteCert()' - Delete a single certificate.
*/
void
cupsdDeleteCert(int pid) /* I - Process ID */
{
cupsd_cert_t *cert, /* Current certificate */
*prev; /* Previous certificate */
char filename[1024]; /* Certificate file */
for (prev = NULL, cert = Certs; cert != NULL; prev = cert, cert = cert->next)
if (cert->pid == pid)
{
/*
* Remove this certificate from the list...
*/
cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdDeleteCert: Removing certificate for PID %d.", pid);
if (prev == NULL)
Certs = cert->next;
else
prev->next = cert->next;
free(cert);
/*
* Delete the file and return...
*/
snprintf(filename, sizeof(filename), "%s/certs/%d", StateDir, pid);
if (unlink(filename))
cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to remove %s!", filename);
return;
}
}
/*
* 'cupsdDeleteAllCerts()' - Delete all certificates...
*/
void
cupsdDeleteAllCerts(void)
{
cupsd_cert_t *cert, /* Current certificate */
*next; /* Next certificate */
char filename[1024]; /* Certificate file */
/*
* Loop through each certificate, deleting them...
*/
for (cert = Certs; cert != NULL; cert = next)
{
/*
* Delete the file...
*/
snprintf(filename, sizeof(filename), "%s/certs/%d", StateDir, cert->pid);
if (unlink(filename))
cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to remove %s!", filename);
/*
* Free memory...
*/
next = cert->next;
free(cert);
}
Certs = NULL;
RootCertTime = 0;
}
/*
* 'cupsdFindCert()' - Find a certificate.
*/
cupsd_cert_t * /* O - Matching certificate or NULL */
cupsdFindCert(const char *certificate) /* I - Certificate */
{
cupsd_cert_t *cert; /* Current certificate */
cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdFindCert(certificate=%s)", certificate);
for (cert = Certs; cert != NULL; cert = cert->next)
if (!ctcompare(certificate, cert->certificate))
{
cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdFindCert: Returning \"%s\".", cert->username);
return (cert);
}
cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdFindCert: Certificate not found.");
return (NULL);
}
/*
* 'cupsdInitCerts()' - Initialize the certificate "system" and root
* certificate.
*/
void
cupsdInitCerts(void)
{
#ifndef HAVE_ARC4RANDOM
cups_file_t *fp; /* /dev/random file */
/*
* Initialize the random number generator using the random device or
* the current time, as available...
*/
if ((fp = cupsFileOpen("/dev/urandom", "rb")) == NULL)
{
struct timeval tod; /* Time of day */
/*
* Get the time in usecs and use it as the initial seed...
*/
gettimeofday(&tod, NULL);
CUPS_SRAND((unsigned)(tod.tv_sec + tod.tv_usec));
}
else
{
unsigned seed; /* Seed for random number generator */
/*
* Read 4 random characters from the random device and use
* them as the seed...
*/
seed = (unsigned)cupsFileGetChar(fp);
seed = (seed << 8) | (unsigned)cupsFileGetChar(fp);
seed = (seed << 8) | (unsigned)cupsFileGetChar(fp);
CUPS_SRAND((seed << 8) | (unsigned)cupsFileGetChar(fp));
cupsFileClose(fp);
}
#endif /* !HAVE_ARC4RANDOM */
/*
* Create a root certificate and return...
*/
if (!RunUser)
cupsdAddCert(0, "root", cupsdDefaultAuthType());
}
/*
* 'ctcompare()' - Compare two strings in constant time.
*/
static int /* O - 0 on match, non-zero on non-match */
ctcompare(const char *a, /* I - First string */
const char *b) /* I - Second string */
{
int result = 0; /* Result */
while (*a && *b)
{
result |= *a ^ *b;
a ++;
b ++;
}
return (result);
}