/*%
* Verify.
*/
static isc_result_t
gssapi_verify(dst_context_t *dctx, const isc_region_t *sig) {
dst_gssapi_signverifyctx_t *ctx = dctx->ctxdata.gssctx;
isc_region_t message, r;
gss_buffer_desc gmessage, gsig;
OM_uint32 minor, gret;
gss_ctx_id_t gssctx = dctx->key->keydata.gssctx;
unsigned char *buf;
char err[1024];
/*
* Convert the data we wish to sign into a structure gssapi can
* understand.
*/
isc_buffer_usedregion(ctx->buffer, &message);
REGION_TO_GBUFFER(message, gmessage);
/*
* XXXMLG
* It seem that gss_verify_mic() modifies the signature buffer,
* at least on Heimdal's implementation. Copy it here to an allocated
* buffer.
*/
buf = isc_mem_allocate(dst__memory_pool, sig->length);
if (buf == NULL)
return (ISC_R_FAILURE);
memmove(buf, sig->base, sig->length);
r.base = buf;
r.length = sig->length;
REGION_TO_GBUFFER(r, gsig);
/*
* Verify the data.
*/
gret = gss_verify_mic(&minor, gssctx, &gmessage, &gsig, NULL);
isc_mem_free(dst__memory_pool, buf);
/*
* Convert return codes into something useful to us.
*/
if (gret != GSS_S_COMPLETE) {
gss_log(3, "GSS verify error: %s",
gss_error_tostring(gret, minor, err, sizeof(err)));
if (gret == GSS_S_DEFECTIVE_TOKEN ||
gret == GSS_S_BAD_SIG ||
gret == GSS_S_DUPLICATE_TOKEN ||
gret == GSS_S_OLD_TOKEN ||
gret == GSS_S_UNSEQ_TOKEN ||
gret == GSS_S_GAP_TOKEN ||
gret == GSS_S_CONTEXT_EXPIRED ||
gret == GSS_S_NO_CONTEXT ||
gret == GSS_S_FAILURE)
return(DST_R_VERIFYFAILURE);
else
return (ISC_R_FAILURE);
}
return (ISC_R_SUCCESS);
}
static isc_result_t
gssapi_sign(dst_context_t *dctx, isc_buffer_t *sig) {
gssapi_ctx_t *ctx = dctx->opaque;
isc_region_t message;
gss_buffer_desc gmessage, gsig;
OM_uint32 minor, gret;
isc_buffer_usedregion(ctx->buffer, &message);
REGION_TO_GBUFFER(message, gmessage);
gret = gss_get_mic(&minor, ctx->context_id,
GSS_C_QOP_DEFAULT, &gmessage, &gsig);
if (gret != 0)
return (ISC_R_FAILURE);
if (gsig.length > isc_buffer_availablelength(sig)) {
gss_release_buffer(&minor, &gsig);
return (ISC_R_NOSPACE);
}
isc_buffer_putmem(sig, gsig.value, gsig.length);
gss_release_buffer(&minor, &gsig);
return (ISC_R_SUCCESS);
}
static inline void
name_to_gbuffer(dns_name_t *name, isc_buffer_t *buffer,
gss_buffer_desc *gbuffer)
{
dns_name_t tname, *namep;
isc_region_t r;
isc_result_t result;
if (!dns_name_isabsolute(name))
namep = name;
else
{
unsigned int labels;
dns_name_init(&tname, NULL);
labels = dns_name_countlabels(name);
dns_name_getlabelsequence(name, 0, labels - 1, &tname);
namep = &tname;
}
result = dns_name_toprincipal(namep, buffer);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
isc_buffer_putuint8(buffer, 0);
isc_buffer_usedregion(buffer, &r);
REGION_TO_GBUFFER(r, *gbuffer);
}
static isc_result_t
gssapi_verify(dst_context_t *dctx, const isc_region_t *sig) {
gssapi_ctx_t *ctx = dctx->opaque;
isc_region_t message;
gss_buffer_desc gmessage, gsig;
OM_uint32 minor, gret;
isc_buffer_usedregion(ctx->buffer, &message);
REGION_TO_GBUFFER(message, gmessage);
REGION_TO_GBUFFER(*sig, gsig);
gret = gss_verify_mic(&minor, ctx->context_id, &gmessage, &gsig, NULL);
if (gret != 0)
return (ISC_R_FAILURE);
return (ISC_R_SUCCESS);
}
/*%
* Sign.
*/
static isc_result_t
gssapi_sign(dst_context_t *dctx, isc_buffer_t *sig) {
dst_gssapi_signverifyctx_t *ctx = dctx->ctxdata.gssctx;
isc_region_t message;
gss_buffer_desc gmessage, gsig;
OM_uint32 minor, gret;
gss_ctx_id_t gssctx = dctx->key->keydata.gssctx;
char buf[1024];
/*
* Convert the data we wish to sign into a structure gssapi can
* understand.
*/
isc_buffer_usedregion(ctx->buffer, &message);
REGION_TO_GBUFFER(message, gmessage);
/*
* Generate the signature.
*/
gret = gss_get_mic(&minor, gssctx, GSS_C_QOP_DEFAULT, &gmessage,
&gsig);
/*
* If it did not complete, we log the result and return a generic
* failure code.
*/
if (gret != GSS_S_COMPLETE) {
gss_log(3, "GSS sign error: %s",
gss_error_tostring(gret, minor, buf, sizeof(buf)));
return (ISC_R_FAILURE);
}
/*
* If it will not fit in our allocated buffer, return that we need
* more space.
*/
if (gsig.length > isc_buffer_availablelength(sig)) {
gss_release_buffer(&minor, &gsig);
return (ISC_R_NOSPACE);
}
/*
* Copy the output into our buffer space, and release the gssapi
* allocated space.
*/
isc_buffer_putmem(sig, gsig.value, (unsigned int)gsig.length);
if (gsig.length != 0U)
gss_release_buffer(&minor, &gsig);
return (ISC_R_SUCCESS);
}
static isc_result_t
gssapi_restore(dst_key_t *key, const char *keystr) {
OM_uint32 major, minor;
unsigned int len;
isc_buffer_t *b = NULL;
isc_region_t r;
gss_buffer_desc gssbuffer;
isc_result_t result;
len = strlen(keystr);
if ((len % 4) != 0U)
return (ISC_R_BADBASE64);
len = (len / 4) * 3;
result = isc_buffer_allocate(key->mctx, &b, len);
if (result != ISC_R_SUCCESS)
return (result);
result = isc_base64_decodestring(keystr, b);
if (result != ISC_R_SUCCESS) {
isc_buffer_free(&b);
return (result);
}
isc_buffer_remainingregion(b, &r);
REGION_TO_GBUFFER(r, gssbuffer);
major = gss_import_sec_context(&minor, &gssbuffer,
&key->keydata.gssctx);
if (major != GSS_S_COMPLETE) {
isc_buffer_free(&b);
return (ISC_R_FAILURE);
}
isc_buffer_free(&b);
return (ISC_R_SUCCESS);
}
isc_result_t
dst_gssapi_acceptctx(gss_cred_id_t cred,
const char *gssapi_keytab,
isc_region_t *intoken, isc_buffer_t **outtoken,
gss_ctx_id_t *ctxout, dns_name_t *principal,
isc_mem_t *mctx)
{
#ifdef GSSAPI
isc_region_t r;
isc_buffer_t namebuf;
gss_buffer_desc gnamebuf = GSS_C_EMPTY_BUFFER, gintoken,
gouttoken = GSS_C_EMPTY_BUFFER;
OM_uint32 gret, minor;
gss_ctx_id_t context = GSS_C_NO_CONTEXT;
gss_name_t gname = NULL;
isc_result_t result;
char buf[1024];
REQUIRE(outtoken != NULL && *outtoken == NULL);
log_cred(cred);
REGION_TO_GBUFFER(*intoken, gintoken);
if (*ctxout == NULL)
context = GSS_C_NO_CONTEXT;
else
context = *ctxout;
if (gssapi_keytab != NULL) {
#ifdef ISC_PLATFORM_GSSAPI_KRB5_HEADER
gret = gsskrb5_register_acceptor_identity(gssapi_keytab);
if (gret != GSS_S_COMPLETE) {
gss_log(3, "failed "
"gsskrb5_register_acceptor_identity(%s): %s",
gssapi_keytab,
gss_error_tostring(gret, minor,
buf, sizeof(buf)));
return (DNS_R_INVALIDTKEY);
}
#else
/*
* Minimize memory leakage by only setting KRB5_KTNAME
* if it needs to change.
*/
const char *old = getenv("KRB5_KTNAME");
if (old == NULL || strcmp(old, gssapi_keytab) != 0) {
char *kt = malloc(strlen(gssapi_keytab) + 13);
if (kt == NULL)
return (ISC_R_NOMEMORY);
sprintf(kt, "KRB5_KTNAME=%s", gssapi_keytab);
if (putenv(kt) != 0)
return (ISC_R_NOMEMORY);
}
#endif
}
gret = gss_accept_sec_context(&minor, &context, cred, &gintoken,
GSS_C_NO_CHANNEL_BINDINGS, &gname,
NULL, &gouttoken, NULL, NULL, NULL);
result = ISC_R_FAILURE;
switch (gret) {
case GSS_S_COMPLETE:
result = ISC_R_SUCCESS;
break;
case GSS_S_CONTINUE_NEEDED:
result = DNS_R_CONTINUE;
break;
case GSS_S_DEFECTIVE_TOKEN:
case GSS_S_DEFECTIVE_CREDENTIAL:
case GSS_S_BAD_SIG:
case GSS_S_DUPLICATE_TOKEN:
case GSS_S_OLD_TOKEN:
case GSS_S_NO_CRED:
case GSS_S_CREDENTIALS_EXPIRED:
case GSS_S_BAD_BINDINGS:
case GSS_S_NO_CONTEXT:
case GSS_S_BAD_MECH:
case GSS_S_FAILURE:
result = DNS_R_INVALIDTKEY;
/* fall through */
default:
gss_log(3, "failed gss_accept_sec_context: %s",
gss_error_tostring(gret, minor, buf, sizeof(buf)));
return (result);
}
if (gouttoken.length > 0) {
RETERR(isc_buffer_allocate(mctx, outtoken, gouttoken.length));
GBUFFER_TO_REGION(gouttoken, r);
RETERR(isc_buffer_copyregion(*outtoken, &r));
(void)gss_release_buffer(&minor, &gouttoken);
}
if (gret == GSS_S_COMPLETE) {
gret = gss_display_name(&minor, gname, &gnamebuf, NULL);
if (gret != GSS_S_COMPLETE) {
gss_log(3, "failed gss_display_name: %s",
gss_error_tostring(gret, minor,
buf, sizeof(buf)));
RETERR(ISC_R_FAILURE);
}
/*
* Compensate for a bug in Solaris8's implementation
* of gss_display_name(). Should be harmless in any
* case, since principal names really should not
* contain null characters.
*/
if (gnamebuf.length > 0 &&
((char *)gnamebuf.value)[gnamebuf.length - 1] == '\0')
gnamebuf.length--;
gss_log(3, "gss-api source name (accept) is %.*s",
(int)gnamebuf.length, (char *)gnamebuf.value);
GBUFFER_TO_REGION(gnamebuf, r);
isc_buffer_init(&namebuf, r.base, r.length);
isc_buffer_add(&namebuf, r.length);
RETERR(dns_name_fromtext(principal, &namebuf, dns_rootname,
0, NULL));
if (gnamebuf.length != 0) {
gret = gss_release_buffer(&minor, &gnamebuf);
if (gret != GSS_S_COMPLETE)
gss_log(3, "failed gss_release_buffer: %s",
gss_error_tostring(gret, minor, buf,
sizeof(buf)));
}
}
*ctxout = context;
out:
if (gname != NULL) {
gret = gss_release_name(&minor, &gname);
if (gret != GSS_S_COMPLETE)
gss_log(3, "failed gss_release_name: %s",
gss_error_tostring(gret, minor, buf,
sizeof(buf)));
}
return (result);
#else
UNUSED(cred);
UNUSED(gssapi_keytab);
UNUSED(intoken);
UNUSED(outtoken);
UNUSED(ctxout);
UNUSED(principal);
UNUSED(mctx);
return (ISC_R_NOTIMPLEMENTED);
#endif
}
isc_result_t
dst_gssapi_initctx(dns_name_t *name, isc_buffer_t *intoken,
isc_buffer_t *outtoken, gss_ctx_id_t *gssctx,
isc_mem_t *mctx, char **err_message)
{
#ifdef GSSAPI
isc_region_t r;
isc_buffer_t namebuf;
gss_name_t gname;
OM_uint32 gret, minor, ret_flags, flags;
gss_buffer_desc gintoken, *gintokenp, gouttoken = GSS_C_EMPTY_BUFFER;
isc_result_t result;
gss_buffer_desc gnamebuf;
unsigned char array[DNS_NAME_MAXTEXT + 1];
/* Client must pass us a valid gss_ctx_id_t here */
REQUIRE(gssctx != NULL);
REQUIRE(mctx != NULL);
isc_buffer_init(&namebuf, array, sizeof(array));
name_to_gbuffer(name, &namebuf, &gnamebuf);
/* Get the name as a GSS name */
gret = gss_import_name(&minor, &gnamebuf, GSS_C_NO_OID, &gname);
if (gret != GSS_S_COMPLETE) {
gss_err_message(mctx, gret, minor, err_message);
result = ISC_R_FAILURE;
goto out;
}
if (intoken != NULL) {
/* Don't call gss_release_buffer for gintoken! */
REGION_TO_GBUFFER(*intoken, gintoken);
gintokenp = &gintoken;
} else {
gintokenp = NULL;
}
/*
* Note that we don't set GSS_C_SEQUENCE_FLAG as Windows DNS
* servers don't like it.
*/
flags = GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG;
gret = gss_init_sec_context(&minor, GSS_C_NO_CREDENTIAL, gssctx,
gname, GSS_SPNEGO_MECHANISM, flags,
0, NULL, gintokenp,
NULL, &gouttoken, &ret_flags, NULL);
if (gret != GSS_S_COMPLETE && gret != GSS_S_CONTINUE_NEEDED) {
gss_err_message(mctx, gret, minor, err_message);
gss_log(3, "Failure initiating security context: %s",
*err_message);
result = ISC_R_FAILURE;
goto out;
}
/*
* XXXSRA Not handled yet: RFC 3645 3.1.1: check ret_flags
* MUTUAL and INTEG flags, fail if either not set.
*/
/*
* RFC 2744 states the a valid output token has a non-zero length.
*/
if (gouttoken.length != 0) {
GBUFFER_TO_REGION(gouttoken, r);
RETERR(isc_buffer_copyregion(outtoken, &r));
(void)gss_release_buffer(&minor, &gouttoken);
}
(void)gss_release_name(&minor, &gname);
if (gret == GSS_S_COMPLETE)
result = ISC_R_SUCCESS;
else
result = DNS_R_CONTINUE;
out:
return (result);
#else
UNUSED(name);
UNUSED(intoken);
UNUSED(outtoken);
UNUSED(gssctx);
UNUSED(mctx);
UNUSED(err_message);
return (ISC_R_NOTIMPLEMENTED);
#endif
}
