static NTSTATUS gensec_krb5_common_client_creds(struct gensec_security *gensec_security,
struct tevent_context *ev,
bool gssapi)
{
struct gensec_krb5_state *gensec_krb5_state;
krb5_error_code ret;
struct ccache_container *ccache_container;
const char *error_string;
const char *principal;
const char *hostname;
krb5_data in_data;
struct tevent_context *previous_ev;
gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
principal = gensec_get_target_principal(gensec_security);
hostname = gensec_get_target_hostname(gensec_security);
ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
ev,
gensec_security->settings->lp_ctx, &ccache_container, &error_string);
switch (ret) {
case 0:
break;
case KRB5KDC_ERR_PREAUTH_FAILED:
case KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN:
return NT_STATUS_LOGON_FAILURE;
case KRB5_KDC_UNREACH:
DEBUG(3, ("Cannot reach a KDC we require to contact %s: %s\n", principal, error_string));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
case KRB5_CC_NOTFOUND:
case KRB5_CC_END:
DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
default:
DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_string));
return NT_STATUS_UNSUCCESSFUL;
}
in_data.length = 0;
/* Do this every time, in case we have weird recursive issues here */
ret = smb_krb5_context_set_event_ctx(gensec_krb5_state->smb_krb5_context, ev, &previous_ev);
if (ret != 0) {
DEBUG(1, ("gensec_krb5_start: Setting event context failed\n"));
return NT_STATUS_NO_MEMORY;
}
if (principal) {
krb5_principal target_principal;
ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
&target_principal);
if (ret == 0) {
ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
&gensec_krb5_state->auth_context,
gensec_krb5_state->ap_req_options,
target_principal,
&in_data, ccache_container->ccache,
&gensec_krb5_state->enc_ticket);
krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
target_principal);
}
} else {
ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
&gensec_krb5_state->auth_context,
gensec_krb5_state->ap_req_options,
gensec_get_target_service(gensec_security),
hostname,
&in_data, ccache_container->ccache,
&gensec_krb5_state->enc_ticket);
}
smb_krb5_context_remove_event_ctx(gensec_krb5_state->smb_krb5_context, previous_ev, ev);
switch (ret) {
case 0:
return NT_STATUS_OK;
case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
case KRB5_KDC_UNREACH:
DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
case KRB5KDC_ERR_PREAUTH_FAILED:
case KRB5KRB_AP_ERR_TKT_EXPIRED:
case KRB5_CC_END:
/* Too much clock skew - we will need to kinit to re-skew the clock */
case KRB5KRB_AP_ERR_SKEW:
case KRB5_KDCREP_SKEW:
{
DEBUG(3, ("kerberos (mk_req) failed: %s\n",
smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
/*fall through*/
}
/* just don't print a message for these really ordinary messages */
case KRB5_FCC_NOFILE:
case KRB5_CC_NOTFOUND:
case ENOENT:
return NT_STATUS_UNSUCCESSFUL;
break;
default:
DEBUG(0, ("kerberos: %s\n",
smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
return NT_STATUS_UNSUCCESSFUL;
}
}
krb5_error_code kinit_to_ccache(TALLOC_CTX *parent_ctx,
struct cli_credentials *credentials,
struct smb_krb5_context *smb_krb5_context,
struct tevent_context *event_ctx,
krb5_ccache ccache,
enum credentials_obtained *obtained,
const char **error_string)
{
krb5_error_code ret;
const char *password;
#ifdef SAMBA4_USES_HEIMDAL
const char *self_service;
#endif
const char *target_service;
time_t kdc_time = 0;
krb5_principal princ;
krb5_principal impersonate_principal;
int tries;
TALLOC_CTX *mem_ctx = talloc_new(parent_ctx);
krb5_get_init_creds_opt *krb_options;
if (!mem_ctx) {
(*error_string) = strerror(ENOMEM);
return ENOMEM;
}
ret = principal_from_credentials(mem_ctx, credentials, smb_krb5_context, &princ, obtained, error_string);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
if (princ == NULL) {
(*error_string) = talloc_asprintf(credentials, "principal, username or realm was not specified in the credentials");
talloc_free(mem_ctx);
return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
}
ret = impersonate_principal_from_credentials(mem_ctx, credentials, smb_krb5_context, &impersonate_principal, error_string);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
#ifdef SAMBA4_USES_HEIMDAL
self_service = cli_credentials_get_self_service(credentials);
#endif
target_service = cli_credentials_get_target_service(credentials);
password = cli_credentials_get_password(credentials);
/* setup the krb5 options we want */
if ((ret = krb5_get_init_creds_opt_alloc(smb_krb5_context->krb5_context, &krb_options))) {
(*error_string) = talloc_asprintf(credentials, "krb5_get_init_creds_opt_alloc failed (%s)\n",
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx));
talloc_free(mem_ctx);
return ret;
}
#ifdef SAMBA4_USES_HEIMDAL /* Disable for now MIT reads defaults when needed */
/* get the defaults */
krb5_get_init_creds_opt_set_default_flags(smb_krb5_context->krb5_context, NULL, NULL, krb_options);
#endif
/* set if we want a forwardable ticket */
switch (cli_credentials_get_krb_forwardable(credentials)) {
case CRED_AUTO_KRB_FORWARDABLE:
break;
case CRED_NO_KRB_FORWARDABLE:
krb5_get_init_creds_opt_set_forwardable(krb_options, FALSE);
break;
case CRED_FORCE_KRB_FORWARDABLE:
krb5_get_init_creds_opt_set_forwardable(krb_options, TRUE);
break;
}
#ifdef SAMBA4_USES_HEIMDAL /* FIXME: MIT does not have this yet */
/*
* In order to work against windows KDCs even if we use
* the netbios domain name as realm, we need to add the following
* flags:
* KRB5_INIT_CREDS_NO_C_CANON_CHECK;
* KRB5_INIT_CREDS_NO_C_NO_EKU_CHECK;
*
* On MIT: Set pkinit_eku_checking to none
*/
krb5_get_init_creds_opt_set_win2k(smb_krb5_context->krb5_context,
krb_options, true);
#else /* MIT */
krb5_get_init_creds_opt_set_canonicalize(krb_options, true);
#endif
tries = 2;
while (tries--) {
#ifdef SAMBA4_USES_HEIMDAL
struct tevent_context *previous_ev;
/* Do this every time, in case we have weird recursive issues here */
ret = smb_krb5_context_set_event_ctx(smb_krb5_context, event_ctx, &previous_ev);
if (ret) {
talloc_free(mem_ctx);
return ret;
}
#endif
if (password) {
if (impersonate_principal) {
#ifdef SAMBA4_USES_HEIMDAL
ret = kerberos_kinit_s4u2_cc(
smb_krb5_context->krb5_context,
ccache, princ, password,
impersonate_principal,
self_service, target_service,
krb_options, NULL, &kdc_time);
#else
talloc_free(mem_ctx);
(*error_string) = "INTERNAL error: s4u2 ops "
"are not supported with MIT build yet";
return EINVAL;
#endif
} else {
ret = kerberos_kinit_password_cc(
smb_krb5_context->krb5_context,
ccache, princ, password,
target_service,
krb_options, NULL, &kdc_time);
}
} else if (impersonate_principal) {
talloc_free(mem_ctx);
(*error_string) = "INTERNAL error: Cannot impersonate principal with just a keyblock. A password must be specified in the credentials";
return EINVAL;
} else {
/* No password available, try to use a keyblock instead */
krb5_keyblock keyblock;
const struct samr_Password *mach_pwd;
mach_pwd = cli_credentials_get_nt_hash(credentials, mem_ctx);
if (!mach_pwd) {
talloc_free(mem_ctx);
(*error_string) = "kinit_to_ccache: No password available for kinit\n";
krb5_get_init_creds_opt_free(smb_krb5_context->krb5_context, krb_options);
#ifdef SAMBA4_USES_HEIMDAL
smb_krb5_context_remove_event_ctx(smb_krb5_context, previous_ev, event_ctx);
#endif
return EINVAL;
}
ret = smb_krb5_keyblock_init_contents(smb_krb5_context->krb5_context,
ENCTYPE_ARCFOUR_HMAC,
mach_pwd->hash, sizeof(mach_pwd->hash),
&keyblock);
if (ret == 0) {
ret = kerberos_kinit_keyblock_cc(smb_krb5_context->krb5_context, ccache,
princ, &keyblock,
target_service, krb_options,
NULL, &kdc_time);
krb5_free_keyblock_contents(smb_krb5_context->krb5_context, &keyblock);
}
}
#ifdef SAMBA4_USES_HEIMDAL
smb_krb5_context_remove_event_ctx(smb_krb5_context, previous_ev, event_ctx);
#endif
if (ret == KRB5KRB_AP_ERR_SKEW || ret == KRB5_KDCREP_SKEW) {
/* Perhaps we have been given an invalid skew, so try again without it */
time_t t = time(NULL);
krb5_set_real_time(smb_krb5_context->krb5_context, t, 0);
} else {
/* not a skew problem */
break;
}
}
krb5_get_init_creds_opt_free(smb_krb5_context->krb5_context, krb_options);
if (ret == KRB5KRB_AP_ERR_SKEW || ret == KRB5_KDCREP_SKEW) {
(*error_string) = talloc_asprintf(credentials, "kinit for %s failed (%s)\n",
cli_credentials_get_principal(credentials, mem_ctx),
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx));
talloc_free(mem_ctx);
return ret;
}
/* cope with ticket being in the future due to clock skew */
if ((unsigned)kdc_time > time(NULL)) {
time_t t = time(NULL);
int time_offset =(unsigned)kdc_time-t;
DEBUG(4,("Advancing clock by %d seconds to cope with clock skew\n", time_offset));
krb5_set_real_time(smb_krb5_context->krb5_context, t + time_offset + 1, 0);
}
if (ret == KRB5KDC_ERR_PREAUTH_FAILED && cli_credentials_wrong_password(credentials)) {
ret = kinit_to_ccache(parent_ctx,
credentials,
smb_krb5_context,
event_ctx,
ccache, obtained,
error_string);
}
if (ret) {
(*error_string) = talloc_asprintf(credentials, "kinit for %s failed (%s)\n",
cli_credentials_get_principal(credentials, mem_ctx),
smb_get_krb5_error_message(smb_krb5_context->krb5_context,
ret, mem_ctx));
talloc_free(mem_ctx);
return ret;
}
DEBUG(10,("kinit for %s succeeded\n",
cli_credentials_get_principal(credentials, mem_ctx)));
talloc_free(mem_ctx);
return 0;
}
static NTSTATUS gensec_krb5_common_client_start(struct gensec_security *gensec_security, bool gssapi)
{
struct gensec_krb5_state *gensec_krb5_state;
krb5_error_code ret;
NTSTATUS nt_status;
struct ccache_container *ccache_container;
const char *hostname;
const char *error_string;
const char *principal;
krb5_data in_data;
struct tevent_context *previous_ev;
hostname = gensec_get_target_hostname(gensec_security);
if (!hostname) {
DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
return NT_STATUS_INVALID_PARAMETER;
}
if (is_ipaddress(hostname)) {
DEBUG(2, ("Cannot do krb5 to an IP address"));
return NT_STATUS_INVALID_PARAMETER;
}
if (strcmp(hostname, "localhost") == 0) {
DEBUG(2, ("krb5 to 'localhost' does not make sense"));
return NT_STATUS_INVALID_PARAMETER;
}
nt_status = gensec_krb5_start(gensec_security, gssapi);
if (!NT_STATUS_IS_OK(nt_status)) {
return nt_status;
}
gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
if (gensec_krb5_state->gssapi) {
/* The Fake GSSAPI modal emulates Samba3, which does not do mutual authentication */
if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
}
} else {
/* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
}
}
principal = gensec_get_target_principal(gensec_security);
ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security),
gensec_security->event_ctx,
gensec_security->settings->lp_ctx, &ccache_container, &error_string);
switch (ret) {
case 0:
break;
case KRB5KDC_ERR_PREAUTH_FAILED:
case KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN:
return NT_STATUS_LOGON_FAILURE;
case KRB5_KDC_UNREACH:
DEBUG(3, ("Cannot reach a KDC we require to contact %s: %s\n", principal, error_string));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
case KRB5_CC_NOTFOUND:
case KRB5_CC_END:
DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
default:
DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_string));
return NT_STATUS_UNSUCCESSFUL;
}
in_data.length = 0;
/* Do this every time, in case we have weird recursive issues here */
ret = smb_krb5_context_set_event_ctx(gensec_krb5_state->smb_krb5_context, gensec_security->event_ctx, &previous_ev);
if (ret != 0) {
DEBUG(1, ("gensec_krb5_start: Setting event context failed\n"));
return NT_STATUS_NO_MEMORY;
}
if (principal) {
krb5_principal target_principal;
ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
&target_principal);
if (ret == 0) {
ret = krb5_mk_req_exact(gensec_krb5_state->smb_krb5_context->krb5_context,
&gensec_krb5_state->auth_context,
gensec_krb5_state->ap_req_options,
target_principal,
&in_data, ccache_container->ccache,
&gensec_krb5_state->enc_ticket);
krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
target_principal);
}
} else {
ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context,
&gensec_krb5_state->auth_context,
gensec_krb5_state->ap_req_options,
gensec_get_target_service(gensec_security),
hostname,
&in_data, ccache_container->ccache,
&gensec_krb5_state->enc_ticket);
}
smb_krb5_context_remove_event_ctx(gensec_krb5_state->smb_krb5_context, previous_ev, gensec_security->event_ctx);
switch (ret) {
case 0:
return NT_STATUS_OK;
case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
case KRB5_KDC_UNREACH:
DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
case KRB5KDC_ERR_PREAUTH_FAILED:
case KRB5KRB_AP_ERR_TKT_EXPIRED:
case KRB5_CC_END:
/* Too much clock skew - we will need to kinit to re-skew the clock */
case KRB5KRB_AP_ERR_SKEW:
case KRB5_KDCREP_SKEW:
{
DEBUG(3, ("kerberos (mk_req) failed: %s\n",
smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
/*fall through*/
}
/* just don't print a message for these really ordinary messages */
case KRB5_FCC_NOFILE:
case KRB5_CC_NOTFOUND:
case ENOENT:
return NT_STATUS_UNSUCCESSFUL;
break;
default:
DEBUG(0, ("kerberos: %s\n",
smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
return NT_STATUS_UNSUCCESSFUL;
}
}
