Currently, we build the string by hand then then construct the principal name with krb5_parse_name. That bypasses the domain_realm section in krb5.conf however.
Switch the code to use krb5_sname_to_principal instead which is more suited to this task. In order for that to work, we change a couple of calling functions to pass down a hostname instead of a principal name, and then pass in "cifs" as the service name. Signed-off-by: Jeff Layton <[email protected]> --- cifs.upcall.c | 47 ++++++++++++++++++++--------------------------- 1 files changed, 20 insertions(+), 27 deletions(-) diff --git a/cifs.upcall.c b/cifs.upcall.c index 0d222cb..9e7f7e2 100644 --- a/cifs.upcall.c +++ b/cifs.upcall.c @@ -324,7 +324,7 @@ static char *find_krb5_cc(const char *dirname, uid_t uid) } static int -cifs_krb5_get_req(const char *principal, const char *ccname, +cifs_krb5_get_req(const char *host, const char *ccname, DATA_BLOB * mechtoken, DATA_BLOB * sess_key) { krb5_error_code ret; @@ -360,10 +360,11 @@ cifs_krb5_get_req(const char *principal, const char *ccname, goto out_free_ccache; } - ret = krb5_parse_name(context, principal, &in_creds.server); + ret = krb5_sname_to_principal(context, host, "cifs", KRB5_NT_UNKNOWN, + &in_creds.server); if (ret) { - syslog(LOG_DEBUG, "%s: unable to parse principal (%s).", - __func__, principal); + syslog(LOG_DEBUG, "%s: unable to convert sname to princ (%s).", + __func__, host); goto out_free_principal; } @@ -371,7 +372,7 @@ cifs_krb5_get_req(const char *principal, const char *ccname, krb5_free_principal(context, in_creds.server); if (ret) { syslog(LOG_DEBUG, "%s: unable to get credentials for %s", - __func__, principal); + __func__, host); goto out_free_principal; } @@ -428,14 +429,14 @@ cifs_krb5_get_req(const char *principal, const char *ccname, &in_data, out_creds, &apreq_pkt); if (ret) { syslog(LOG_DEBUG, "%s: unable to make AP-REQ for %s", - __func__, principal); + __func__, host); goto out_free_auth; } ret = krb5_auth_con_getsendsubkey(context, auth_context, &tokb); if (ret) { syslog(LOG_DEBUG, "%s: unable to get session key for %s", - __func__, principal); + __func__, host); goto out_free_auth; } @@ -480,17 +481,16 @@ out_free_context: * ret: 0 - success, others - failure */ static int -handle_krb5_mech(const char *oid, const char *principal, DATA_BLOB * secblob, +handle_krb5_mech(const char *oid, const char *host, DATA_BLOB * secblob, DATA_BLOB * sess_key, const char *ccname) { int retval; DATA_BLOB tkt, tkt_wrapped; - syslog(LOG_DEBUG, "%s: getting service ticket for %s", __func__, - principal); + syslog(LOG_DEBUG, "%s: getting service ticket for %s", __func__, host); /* get a kerberos ticket for the service and extract the session key */ - retval = cifs_krb5_get_req(principal, ccname, &tkt, sess_key); + retval = cifs_krb5_get_req(host, ccname, &tkt, sess_key); if (retval) { syslog(LOG_DEBUG, "%s: failed to obtain service ticket (%d)", __func__, retval); @@ -782,7 +782,6 @@ int main(const int argc, char *const argv[]) int c, try_dns = 0, legacy_uid = 0; char *buf, *ccname = NULL; char hostbuf[NI_MAXHOST], *host; - char princ[NI_MAXHOST + 5]; /* 5 == len of "cifs/" */ struct decoded_args arg; const char *oid; uid_t uid; @@ -921,29 +920,23 @@ int main(const int argc, char *const argv[]) retry_new_hostname: lowercase_string(host); - /* try "cifs/hostname" first */ - rc = snprintf(princ, sizeof(princ), "cifs/%s", host); - if (rc < 0 || (size_t)rc >= sizeof(princ)) { - syslog(LOG_ERR,"Unable to set hostname %s in buffer.", host); - goto out; - } - - rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname); + rc = handle_krb5_mech(oid, host, &secblob, &sess_key, ccname); if (!rc) break; /* - * If hostname has a '.', assume it's a FQDN, otherwise we want to - * guess the domainname. + * If hostname has a '.', assume it's a FQDN, otherwise we + * want to guess the domainname. */ if (!strchr(host, '.')) { struct addrinfo hints; struct addrinfo *ai; char *domainname; + char fqdn[NI_MAXHOST]; /* - * use getaddrinfo() to resolve the hostname of the server - * and set ai_canonname. + * use getaddrinfo() to resolve the hostname of the + * server and set ai_canonname. */ memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_UNSPEC; @@ -963,16 +956,16 @@ retry_new_hostname: break; } lowercase_string(domainname); - rc = snprintf(princ, sizeof(princ), "cifs/%s%s", + rc = snprintf(fqdn, sizeof(fqdn), "%s%s", host, domainname); freeaddrinfo(ai); - if (rc < 0 || (size_t)rc >= sizeof(princ)) { + if (rc < 0 || (size_t)rc >= sizeof(fqdn)) { syslog(LOG_ERR, "Problem setting hostname in string: %ld", rc); rc = -EINVAL; break; } - rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname); + rc = handle_krb5_mech(oid, fqdn, &secblob, &sess_key, ccname); if (!rc) break; } -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
