krb5_error_code KRB5_CALLCONV
krb5_mk_safe(krb5_context context, krb5_auth_context auth_context,
const krb5_data *userdata, krb5_data *outbuf,
krb5_replay_data *outdata)
{
krb5_error_code retval;
krb5_key key;
krb5_replay_data replaydata;
/* Clear replaydata block */
memset(&replaydata, 0, sizeof(krb5_replay_data));
/* Get key */
if ((key = auth_context->send_subkey) == NULL)
key = auth_context->key;
/* Get replay info */
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) &&
(auth_context->rcache == NULL))
return KRB5_RC_REQUIRED;
if (((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
(outdata == NULL))
/* Need a better error */
return KRB5_RC_REQUIRED;
if (!auth_context->local_addr)
return KRB5_LOCAL_ADDR_REQUIRED;
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME)) {
if ((retval = krb5_us_timeofday(context, &replaydata.timestamp,
&replaydata.usec)))
return retval;
if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) {
outdata->timestamp = replaydata.timestamp;
outdata->usec = replaydata.usec;
}
}
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) {
replaydata.seq = auth_context->local_seq_number++;
if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)
outdata->seq = replaydata.seq;
}
{
krb5_address * premote_fulladdr = NULL;
krb5_address * plocal_fulladdr;
krb5_address remote_fulladdr;
krb5_address local_fulladdr;
krb5_cksumtype sumtype;
CLEANUP_INIT(2);
if (auth_context->local_port) {
if (!(retval = krb5_make_fulladdr(context, auth_context->local_addr,
auth_context->local_port,
&local_fulladdr))){
CLEANUP_PUSH(local_fulladdr.contents, free);
plocal_fulladdr = &local_fulladdr;
} else {
goto error;
}
} else {
plocal_fulladdr = auth_context->local_addr;
}
if (auth_context->remote_addr) {
if (auth_context->remote_port) {
if (!(retval = krb5_make_fulladdr(context,auth_context->remote_addr,
auth_context->remote_port,
&remote_fulladdr))){
CLEANUP_PUSH(remote_fulladdr.contents, free);
premote_fulladdr = &remote_fulladdr;
} else {
CLEANUP_DONE();
goto error;
}
} else {
premote_fulladdr = auth_context->remote_addr;
}
}
{
krb5_enctype enctype = krb5_k_key_enctype(context, key);
unsigned int nsumtypes;
unsigned int i;
krb5_cksumtype *sumtypes;
retval = krb5_c_keyed_checksum_types (context, enctype,
&nsumtypes, &sumtypes);
if (retval) {
CLEANUP_DONE ();
goto error;
}
if (nsumtypes == 0) {
retval = KRB5_BAD_ENCTYPE;
krb5_free_cksumtypes (context, sumtypes);
CLEANUP_DONE ();
goto error;
}
for (i = 0; i < nsumtypes; i++)
if (auth_context->safe_cksumtype == sumtypes[i])
break;
krb5_free_cksumtypes (context, sumtypes);
if (i < nsumtypes)
sumtype = auth_context->safe_cksumtype;
else {
switch (enctype) {
case ENCTYPE_DES_CBC_MD4:
sumtype = CKSUMTYPE_RSA_MD4_DES;
break;
case ENCTYPE_DES_CBC_MD5:
case ENCTYPE_DES_CBC_CRC:
sumtype = CKSUMTYPE_RSA_MD5_DES;
break;
default:
retval = krb5int_c_mandatory_cksumtype(context, enctype,
&sumtype);
if (retval) {
CLEANUP_DONE();
goto error;
}
break;
}
}
}
if ((retval = krb5_mk_safe_basic(context, userdata, key, &replaydata,
plocal_fulladdr, premote_fulladdr,
sumtype, outbuf))) {
CLEANUP_DONE();
goto error;
}
CLEANUP_DONE();
}
if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) {
krb5_donot_replay replay;
if ((retval = krb5_gen_replay_name(context, auth_context->local_addr,
"_safe", &replay.client))) {
free(outbuf);
goto error;
}
replay.server = ""; /* XXX */
replay.msghash = NULL;
replay.cusec = replaydata.usec;
replay.ctime = replaydata.timestamp;
if ((retval = krb5_rc_store(context, auth_context->rcache, &replay))) {
/* should we really error out here? XXX */
free(outbuf);
goto error;
}
free(replay.client);
}
return 0;
error:
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE))
auth_context->local_seq_number--;
return retval;
}
static krb5_error_code
client_process(krb5_context kcontext,
void *client_plugin_context,
void *client_request_context,
krb5_get_init_creds_opt *opt,
preauth_get_client_data_proc client_get_data_proc,
struct _krb5_preauth_client_rock *rock,
krb5_kdc_req *request,
krb5_data *encoded_request_body,
krb5_data *encoded_previous_request,
krb5_pa_data *pa_data,
krb5_prompter_fct prompter,
void *prompter_data,
preauth_get_as_key_proc gak_fct,
void *gak_data,
krb5_data *salt, krb5_data *s2kparams,
krb5_keyblock *as_key,
krb5_pa_data **out_pa_data)
{
krb5_pa_data *send_pa;
krb5_checksum checksum;
krb5_enctype enctype;
krb5_cksumtype *cksumtypes;
krb5_error_code status = 0;
krb5_int32 cksumtype, *enctypes;
unsigned int i, n_enctypes, cksumtype_count;
int num_gic_info = 0;
krb5_gic_opt_pa_data *gic_info;
status = krb5_get_init_creds_opt_get_pa(kcontext, opt,
&num_gic_info, &gic_info);
if (status && status != ENOENT) {
#ifdef DEBUG
fprintf(stderr, "Error from krb5_get_init_creds_opt_get_pa: %s\n",
error_message(status));
#endif
return status;
}
#ifdef DEBUG
fprintf(stderr, "(cksum_body) Got the following gic options:\n");
#endif
for (i = 0; i < num_gic_info; i++) {
#ifdef DEBUG
fprintf(stderr, " '%s' = '%s'\n", gic_info[i].attr, gic_info[i].value);
#endif
}
krb5_get_init_creds_opt_free_pa(kcontext, num_gic_info, gic_info);
memset(&checksum, 0, sizeof(checksum));
/* Get the user's long-term key if we haven't asked for it yet. Try
* all of the encryption types which the server supports. */
if (as_key->length == 0) {
if ((pa_data != NULL) && (pa_data->length >= 4)) {
#ifdef DEBUG
fprintf(stderr, "%d bytes of preauth data.\n", pa_data->length);
#endif
n_enctypes = pa_data->length / 4;
enctypes = (krb5_int32*) pa_data->contents;
} else {
n_enctypes = request->nktypes;
}
for (i = 0; i < n_enctypes; i++) {
if ((pa_data != NULL) && (pa_data->length >= 4)) {
memcpy(&enctype, pa_data->contents + 4 * i, 4);
enctype = ntohl(enctype);
} else {
enctype = request->ktype[i];
}
#ifdef DEBUG
fprintf(stderr, "Asking for AS key (type = %d).\n", enctype);
#endif
status = (*gak_fct)(kcontext, request->client, enctype,
prompter, prompter_data,
salt, s2kparams, as_key, gak_data);
if (status == 0)
break;
}
if (status != 0)
return status;
}
#ifdef DEBUG
fprintf(stderr, "Got AS key (type = %d).\n", as_key->enctype);
#endif
/* Determine an appropriate checksum type for this key. */
cksumtype_count = 0;
cksumtypes = NULL;
status = krb5_c_keyed_checksum_types(kcontext, as_key->enctype,
&cksumtype_count, &cksumtypes);
if (status != 0)
return status;
/* Generate the checksum. */
for (i = 0; i < cksumtype_count; i++) {
status = krb5_c_make_checksum(kcontext, cksumtypes[i], as_key,
KRB5_KEYUSAGE_TGS_REQ_AUTH_CKSUM,
encoded_request_body,
&checksum);
if (status == 0) {
#ifdef DEBUG
fprintf(stderr, "Made checksum (type = %d, %d bytes).\n",
checksum.checksum_type, encoded_request_body->length);
#endif
break;
}
}
cksumtype = htonl(cksumtypes[i]);
krb5_free_cksumtypes(kcontext, cksumtypes);
if (status != 0) {
if (checksum.length > 0)
krb5_free_checksum_contents(kcontext, &checksum);
return status;
}
/* Allocate the preauth data structure. */
send_pa = malloc(sizeof(krb5_pa_data));
if (send_pa == NULL) {
krb5_free_checksum_contents(kcontext, &checksum);
return ENOMEM;
}
send_pa->pa_type = KRB5_PADATA_CKSUM_BODY_REQ;
send_pa->length = 4 + checksum.length;
send_pa->contents = malloc(4 + checksum.length);
if (send_pa->contents == NULL) {
krb5_free_checksum_contents(kcontext, &checksum);
free(send_pa);
return ENOMEM;
}
/* Store the checksum. */
memcpy(send_pa->contents, &cksumtype, 4);
memcpy(send_pa->contents + 4, checksum.contents, checksum.length);
*out_pa_data = send_pa;
/* Clean up. */
krb5_free_checksum_contents(kcontext, &checksum);
return 0;
}
/* Verify a request from a client. */
static krb5_error_code
server_verify(krb5_context kcontext,
struct _krb5_db_entry_new *client,
krb5_data *req_pkt,
krb5_kdc_req *request,
krb5_enc_tkt_part *enc_tkt_reply,
krb5_pa_data *data,
preauth_get_entry_data_proc server_get_entry_data,
void *pa_module_context,
void **pa_request_context,
krb5_data **e_data,
krb5_authdata ***authz_data)
{
krb5_int32 cksumtype;
krb5_checksum checksum;
krb5_boolean valid;
krb5_data *key_data, *req_body;
krb5_keyblock *keys, *key;
size_t length;
int i;
unsigned int j, cksumtypes_count;
krb5_cksumtype *cksumtypes;
krb5_error_code status;
struct server_stats *stats;
krb5_data *test_edata;
test_svr_req_ctx *svr_req_ctx;
krb5_authdata **my_authz_data = NULL;
stats = pa_module_context;
#ifdef DEBUG
fprintf(stderr, "cksum_body: server_verify\n");
#endif
/* Verify the preauth data. Start with the checksum type. */
if (data->length < 4) {
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
memcpy(&cksumtype, data->contents, 4);
memset(&checksum, 0, sizeof(checksum));
checksum.checksum_type = ntohl(cksumtype);
/* Verify that the amount of data we have left is what we expect. */
if (krb5_c_checksum_length(kcontext, checksum.checksum_type,
&length) != 0) {
#ifdef DEBUG
fprintf(stderr, "Error determining checksum size (type = %d). "
"Is it supported?\n", checksum.checksum_type);
#endif
stats->failures++;
return KRB5KDC_ERR_SUMTYPE_NOSUPP;
}
if (data->length - 4 != length) {
#ifdef DEBUG
fprintf(stderr, "Checksum size doesn't match client packet size.\n");
#endif
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
checksum.length = length;
/* Pull up the client's keys. */
key_data = NULL;
if ((*server_get_entry_data)(kcontext, request, client,
krb5plugin_preauth_keys, &key_data) != 0) {
#ifdef DEBUG
fprintf(stderr, "Error retrieving client keys.\n");
#endif
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
/* Find the key which would have been used to generate the checksum. */
keys = (krb5_keyblock *) key_data->data;
key = NULL;
for (i = 0; keys[i].enctype != 0; i++) {
key = &keys[i];
cksumtypes_count = 0;
cksumtypes = NULL;
if (krb5_c_keyed_checksum_types(kcontext, key->enctype,
&cksumtypes_count, &cksumtypes) != 0)
continue;
for (j = 0; j < cksumtypes_count; j++) {
if (cksumtypes[j] == checksum.checksum_type)
break;
}
if (cksumtypes != NULL)
krb5_free_cksumtypes(kcontext, cksumtypes);
if (j < cksumtypes_count) {
#ifdef DEBUG
fprintf(stderr, "Found checksum key.\n");
#endif
break;
}
}
if ((key == NULL) || (key->enctype == 0)) {
for (i = 0; keys[i].enctype != 0; i++)
krb5_free_keyblock_contents(kcontext, &keys[i]);
krb5_free_data(kcontext, key_data);
stats->failures++;
return KRB5KDC_ERR_SUMTYPE_NOSUPP;
}
/* Save a copy of the key. */
if (krb5_copy_keyblock(kcontext, &keys[i], &key) != 0) {
for (i = 0; keys[i].enctype != 0; i++)
krb5_free_keyblock_contents(kcontext, &keys[i]);
krb5_free_data(kcontext, key_data);
stats->failures++;
return KRB5KDC_ERR_SUMTYPE_NOSUPP;
}
for (i = 0; keys[i].enctype != 0; i++)
krb5_free_keyblock_contents(kcontext, &keys[i]);
krb5_free_data(kcontext, key_data);
/* Rebuild a copy of the client's request-body. If we were serious
* about doing this with any chance of working interoperability, we'd
* extract the structure directly from the req_pkt structure. This
* will probably work if it's us on both ends, though. */
req_body = NULL;
if ((*server_get_entry_data)(kcontext, request, client,
krb5plugin_preauth_request_body,
&req_body) != 0) {
krb5_free_keyblock(kcontext, key);
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
#ifdef DEBUG
fprintf(stderr, "AS key type %d, checksum type %d, %d bytes.\n",
key->enctype, checksum.checksum_type, req_body->length);
#endif
/* Verify the checksum itself. */
checksum.contents = data->contents + 4;
valid = FALSE;
status = krb5_c_verify_checksum(kcontext, key,
KRB5_KEYUSAGE_TGS_REQ_AUTH_CKSUM,
req_body, &checksum, &valid);
/* Clean up. */
krb5_free_data(kcontext, req_body);
krb5_free_keyblock(kcontext, key);
/* Evaluate our results. */
if ((status != 0) || (!valid)) {
#ifdef DEBUG
if (status != 0) {
fprintf(stderr, "Error in checksum verification.\n");
} else {
fprintf(stderr, "Checksum mismatch.\n");
}
#endif
/* Return edata to exercise code that handles edata... */
test_edata = malloc(sizeof(*test_edata));
if (test_edata != NULL) {
test_edata->data = malloc(20);
if (test_edata->data == NULL) {
free(test_edata);
} else {
test_edata->length = 20;
memset(test_edata->data, 'F', 20); /* fill it with junk */
*e_data = test_edata;
}
}
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
/*
* Return some junk authorization data just to exercise the
* code path handling the returned authorization data.
*
* NOTE that this is NOT VALID authorization data!
*/
#ifdef DEBUG
fprintf(stderr, "cksum_body: doing authorization data!\n");
#endif
my_authz_data = malloc(2 * sizeof(*my_authz_data));
if (my_authz_data != NULL) {
#if 1 /* USE_5000_AD */
#define AD_ALLOC_SIZE 5000
/* ad_header consists of a sequence tag (0x30) and length
* (0x82 0x1384) followed by octet string tag (0x04) and
* length (0x82 0x1380) */
krb5_octet ad_header[] = {0x30, 0x82, 0x13, 0x84, 0x04, 0x82, 0x13, 0x80};
#else
#define AD_ALLOC_SIZE 100
/* ad_header consists of a sequence tag (0x30) and length
* (0x62) followed by octet string tag (0x04) and length
* (0x60) */
krb5_octet ad_header[] = {0x30, 0x62, 0x04, 0x60};
#endif
my_authz_data[1] = NULL;
my_authz_data[0] = malloc(sizeof(krb5_authdata));
if (my_authz_data[0] == NULL) {
free(my_authz_data);
return ENOMEM;
}
my_authz_data[0]->contents = malloc(AD_ALLOC_SIZE);
if (my_authz_data[0]->contents == NULL) {
free(my_authz_data[0]);
free(my_authz_data);
return ENOMEM;
}
memset(my_authz_data[0]->contents, '\0', AD_ALLOC_SIZE);
my_authz_data[0]->magic = KV5M_AUTHDATA;
my_authz_data[0]->ad_type = 1;
my_authz_data[0]->length = AD_ALLOC_SIZE;
memcpy(my_authz_data[0]->contents, ad_header, sizeof(ad_header));
snprintf(my_authz_data[0]->contents + sizeof(ad_header),
AD_ALLOC_SIZE - sizeof(ad_header),
"cksum authorization data: %d bytes worth!\n", AD_ALLOC_SIZE);
*authz_data = my_authz_data;
#ifdef DEBUG
fprintf(stderr, "Returning %d bytes of authorization data\n",
AD_ALLOC_SIZE);
#endif
}
/* Return edata to exercise code that handles edata... */
test_edata = malloc(sizeof(*test_edata));
if (test_edata != NULL) {
test_edata->data = malloc(20);
if (test_edata->data == NULL) {
free(test_edata);
} else {
test_edata->length = 20;
memset(test_edata->data, 'S', 20); /* fill it with junk */
*e_data = test_edata;
}
}
/* Return a request context to exercise code that handles it */
svr_req_ctx = malloc(sizeof(*svr_req_ctx));
if (svr_req_ctx != NULL) {
svr_req_ctx->value1 = 111111;
svr_req_ctx->value2 = 222222;
#ifdef DEBUG
fprintf(stderr, "server_verify: returning context at %p\n",
svr_req_ctx);
#endif
}
*pa_request_context = svr_req_ctx;
/* Note that preauthentication succeeded. */
enc_tkt_reply->flags |= TKT_FLG_PRE_AUTH;
stats->successes++;
return 0;
}
/* Verify a request from a client. */
static krb5_error_code
server_verify(krb5_context kcontext,
struct _krb5_db_entry_new *client,
krb5_data *req_pkt,
krb5_kdc_req *request,
krb5_enc_tkt_part *enc_tkt_reply,
krb5_pa_data *data,
preauth_get_entry_data_proc server_get_entry_data,
void *pa_module_context,
void **pa_request_context,
krb5_data **e_data)
{
krb5_int32 cksumtype;
krb5_checksum checksum;
krb5_boolean valid;
krb5_data *key_data, *req_body;
krb5_keyblock *keys, *key;
size_t length;
int i;
unsigned int j, cksumtypes_count;
krb5_cksumtype *cksumtypes;
krb5_error_code status;
struct server_stats *stats;
krb5_data *test_edata;
stats = pa_module_context;
/* Verify the preauth data. Start with the checksum type. */
if (data->length < 4) {
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
memcpy(&cksumtype, data->contents, 4);
memset(&checksum, 0, sizeof(checksum));
checksum.checksum_type = ntohl(cksumtype);
/* Verify that the amount of data we have left is what we expect. */
if (krb5_c_checksum_length(kcontext, checksum.checksum_type,
&length) != 0) {
#ifdef DEBUG
fprintf(stderr, "Error determining checksum size (type = %d). "
"Is it supported?\n", checksum.checksum_type);
#endif
stats->failures++;
return KRB5KDC_ERR_SUMTYPE_NOSUPP;
}
if (data->length - 4 != length) {
#ifdef DEBUG
fprintf(stderr, "Checksum size doesn't match client packet size.\n");
#endif
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
checksum.length = length;
/* Pull up the client's keys. */
key_data = NULL;
if ((*server_get_entry_data)(kcontext, request, client,
krb5plugin_preauth_keys, &key_data) != 0) {
#ifdef DEBUG
fprintf(stderr, "Error retrieving client keys.\n");
#endif
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
/* Find the key which would have been used to generate the checksum. */
keys = (krb5_keyblock *) key_data->data;
key = NULL;
for (i = 0; keys[i].enctype != 0; i++) {
key = &keys[i];
cksumtypes_count = 0;
cksumtypes = NULL;
if (krb5_c_keyed_checksum_types(kcontext, key->enctype,
&cksumtypes_count, &cksumtypes) != 0)
continue;
for (j = 0; j < cksumtypes_count; j++) {
if (cksumtypes[j] == checksum.checksum_type)
break;
}
if (cksumtypes != NULL)
krb5_free_cksumtypes(kcontext, cksumtypes);
if (j < cksumtypes_count) {
#ifdef DEBUG
fprintf(stderr, "Found checksum key.\n");
#endif
break;
}
}
if ((key == NULL) || (key->enctype == 0)) {
for (i = 0; keys[i].enctype != 0; i++)
krb5_free_keyblock_contents(kcontext, &keys[i]);
krb5_free_data(kcontext, key_data);
stats->failures++;
return KRB5KDC_ERR_SUMTYPE_NOSUPP;
}
/* Save a copy of the key. */
if (krb5_copy_keyblock(kcontext, &keys[i], &key) != 0) {
for (i = 0; keys[i].enctype != 0; i++)
krb5_free_keyblock_contents(kcontext, &keys[i]);
krb5_free_data(kcontext, key_data);
stats->failures++;
return KRB5KDC_ERR_SUMTYPE_NOSUPP;
}
for (i = 0; keys[i].enctype != 0; i++)
krb5_free_keyblock_contents(kcontext, &keys[i]);
krb5_free_data(kcontext, key_data);
/* Rebuild a copy of the client's request-body. If we were serious
* about doing this with any chance of working interoperability, we'd
* extract the structure directly from the req_pkt structure. This
* will probably work if it's us on both ends, though. */
req_body = NULL;
if ((*server_get_entry_data)(kcontext, request, client,
krb5plugin_preauth_request_body,
&req_body) != 0) {
krb5_free_keyblock(kcontext, key);
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
#ifdef DEBUG
fprintf(stderr, "AS key type %d, checksum type %d, %d bytes.\n",
key->enctype, checksum.checksum_type, req_body->length);
#endif
/* Verify the checksum itself. */
checksum.contents = data->contents + 4;
valid = FALSE;
status = krb5_c_verify_checksum(kcontext, key,
KRB5_KEYUSAGE_TGS_REQ_AUTH_CKSUM,
req_body, &checksum, &valid);
/* Clean up. */
krb5_free_data(kcontext, req_body);
krb5_free_keyblock(kcontext, key);
/* Evaluate our results. */
if ((status != 0) || (!valid)) {
#ifdef DEBUG
if (status != 0) {
fprintf(stderr, "Error in checksum verification.\n");
} else {
fprintf(stderr, "Checksum mismatch.\n");
}
#endif
/* Return edata to exercise code that handles edata... */
test_edata = malloc(sizeof(*test_edata));
if (test_edata != NULL) {
test_edata->data = malloc(20);
if (test_edata->data == NULL) {
free(test_edata);
} else {
test_edata->length = 20;
memset(test_edata->data, 'F', 20); /* fill it with junk */
*e_data = test_edata;
}
}
stats->failures++;
return KRB5KDC_ERR_PREAUTH_FAILED;
}
/* Return edata to exercise code that handles edata... */
test_edata = malloc(sizeof(*test_edata));
if (test_edata != NULL) {
test_edata->data = malloc(20);
if (test_edata->data == NULL) {
free(test_edata);
} else {
test_edata->length = 20;
memset(test_edata->data, 'S', 20); /* fill it with junk */
*e_data = test_edata;
}
}
/* Note that preauthentication succeeded. */
enc_tkt_reply->flags |= TKT_FLG_PRE_AUTH;
stats->successes++;
return 0;
}
int
ksm_rgenerate_out_msg(struct snmp_secmod_outgoing_params *parms)
{
krb5_auth_context auth_context = NULL;
krb5_error_code retcode;
krb5_ccache cc = NULL;
int retval = SNMPERR_SUCCESS;
krb5_data outdata, ivector;
krb5_keyblock *subkey = NULL;
#ifdef MIT_NEW_CRYPTO
krb5_data input;
krb5_enc_data output;
unsigned int numcksumtypes;
krb5_cksumtype *cksumtype_array;
#else /* MIT_NEW_CRYPTO */
krb5_encrypt_block eblock;
#endif /* MIT_NEW_CRYPTO */
size_t blocksize, encrypted_length;
unsigned char *encrypted_data = NULL;
int zero = 0, i;
u_char *cksum_pointer, *endp = *parms->wholeMsg;
krb5_cksumtype cksumtype;
krb5_checksum pdu_checksum;
u_char **wholeMsg = parms->wholeMsg;
size_t *offset = parms->wholeMsgOffset, seq_offset;
struct ksm_secStateRef *ksm_state = (struct ksm_secStateRef *)
parms->secStateRef;
int rc;
DEBUGMSGTL(("ksm", "Starting KSM processing\n"));
outdata.length = 0;
outdata.data = NULL;
ivector.length = 0;
ivector.data = NULL;
pdu_checksum.contents = NULL;
if (!ksm_state) {
/*
* If we don't have a ksm_state, then we're a request. Get a
* credential cache and build a ap_req.
*/
retcode = krb5_cc_default(kcontext, &cc);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_cc_default failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Set credential cache successfully\n"));
/*
* This seems odd, since we don't need this until later (or earlier,
* depending on how you look at it), but because the most likely
* errors are Kerberos at this point, I'll get this now to save
* time not encoding the rest of the packet.
*
* Also, we need the subkey to encrypt the PDU (if required).
*/
retcode =
krb5_mk_req(kcontext, &auth_context,
AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
(char *) service_name, parms->session->peername, NULL,
cc, &outdata);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_mk_req failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: ticket retrieved successfully for \"%s/%s\" "
"(may not be actual ticket sname)\n", service_name,
parms->session->peername));
} else {
/*
* Grab the auth_context from our security state reference
*/
auth_context = ksm_state->auth_context;
/*
* Bundle up an AP_REP. Note that we do this only when we
* have a security state reference (which means we're in an agent
* and we're sending a response).
*/
DEBUGMSGTL(("ksm", "KSM: Starting reply processing.\n"));
retcode = krb5_mk_rep(kcontext, auth_context, &outdata);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_mk_rep failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Finished with krb5_mk_rep()\n"));
}
/*
* If we have to encrypt the PDU, do that now
*/
if (parms->secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
DEBUGMSGTL(("ksm", "KSM: Starting PDU encryption.\n"));
/*
* It's weird -
*
* If we're on the manager, it's a local subkey (because that's in
* our AP_REQ)
*
* If we're on the agent, it's a remote subkey (because that comes
* FROM the received AP_REQ).
*/
if (ksm_state)
retcode = krb5_auth_con_getremotesubkey(kcontext, auth_context,
&subkey);
else
retcode = krb5_auth_con_getlocalsubkey(kcontext, auth_context,
&subkey);
if (retcode) {
DEBUGMSGTL(("ksm",
"KSM: krb5_auth_con_getlocalsubkey failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
/*
* Note that here we need to handle different things between the
* old and new crypto APIs. First, we need to get the final encrypted
* length of the PDU.
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_encrypt_length(kcontext, subkey->enctype,
parms->scopedPduLen,
&encrypted_length);
if (retcode) {
DEBUGMSGTL(("ksm",
"Encryption length calculation failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#else /* MIT_NEW_CRYPTO */
krb5_use_enctype(kcontext, &eblock, subkey->enctype);
retcode = krb5_process_key(kcontext, &eblock, subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_process_key failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
encrypted_length = krb5_encrypt_size(parms->scopedPduLen,
eblock.crypto_entry);
#endif /* MIT_NEW_CRYPTO */
encrypted_data = malloc(encrypted_length);
if (!encrypted_data) {
DEBUGMSGTL(("ksm",
"KSM: Unable to malloc %d bytes for encrypt "
"buffer: %s\n", parms->scopedPduLen,
strerror(errno)));
retval = SNMPERR_MALLOC;
#ifndef MIT_NEW_CRYPTO
krb5_finish_key(kcontext, &eblock);
#endif /* ! MIT_NEW_CRYPTO */
goto error;
}
/*
* We need to set up a blank initialization vector for the encryption.
* Use a block of all zero's (which is dependent on the block size
* of the encryption method).
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_block_size(kcontext, subkey->enctype, &blocksize);
if (retcode) {
DEBUGMSGTL(("ksm",
"Unable to determine crypto block size: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#else /* MIT_NEW_CRYPTO */
blocksize =
krb5_enctype_array[subkey->enctype]->system->block_length;
#endif /* MIT_NEW_CRYPTO */
ivector.data = malloc(blocksize);
if (!ivector.data) {
DEBUGMSGTL(("ksm", "Unable to allocate %d bytes for ivector\n",
blocksize));
retval = SNMPERR_MALLOC;
goto error;
}
ivector.length = blocksize;
memset(ivector.data, 0, blocksize);
/*
* Finally! Do the encryption!
*/
#ifdef MIT_NEW_CRYPTO
input.data = (char *) parms->scopedPdu;
input.length = parms->scopedPduLen;
output.ciphertext.data = (char *) encrypted_data;
output.ciphertext.length = encrypted_length;
retcode =
krb5_c_encrypt(kcontext, subkey, KSM_KEY_USAGE_ENCRYPTION,
&ivector, &input, &output);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_encrypt(kcontext, (krb5_pointer) parms->scopedPdu,
(krb5_pointer) encrypted_data,
parms->scopedPduLen, &eblock, ivector.data);
krb5_finish_key(kcontext, &eblock);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_encrypt failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
*offset = 0;
rc = asn_realloc_rbuild_string(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
encrypted_data,
encrypted_length);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building encrypted payload failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Encryption complete.\n"));
} else {
/*
* Plaintext PDU (not encrypted)
*/
if (*parms->wholeMsgLen < parms->scopedPduLen) {
DEBUGMSGTL(("ksm", "Not enough room for plaintext PDU.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
}
/*
* Start encoding the msgSecurityParameters
*
* For now, use 0 for the response hint
*/
DEBUGMSGTL(("ksm", "KSM: scopedPdu added to payload\n"));
seq_offset = *offset;
rc = asn_realloc_rbuild_int(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_INTEGER),
(long *) &zero, sizeof(zero));
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_string(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
(u_char *) outdata.data,
outdata.length);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm AP_REQ failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
/*
* Now, we need to pick the "right" checksum algorithm. For old
* crypto, just pick CKSUMTYPE_RSA_MD5_DES; for new crypto, pick
* one of the "approved" ones.
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_keyed_checksum_types(kcontext, subkey->enctype,
&numcksumtypes, &cksumtype_array);
if (retcode) {
DEBUGMSGTL(("ksm", "Unable to find appropriate keyed checksum: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
if (numcksumtypes <= 0) {
DEBUGMSGTL(("ksm", "We received a list of zero cksumtypes for this "
"enctype (%d)\n", subkey->enctype));
snmp_set_detail("No valid checksum type for this encryption type");
retval = SNMPERR_KRB5;
goto error;
}
/*
* It's not clear to me from the API which checksum you're supposed
* to support, so I'm taking a guess at the first one
*/
cksumtype = cksumtype_array[0];
krb5_free_cksumtypes(kcontext, cksumtype_array);
DEBUGMSGTL(("ksm", "KSM: Choosing checksum type of %d (subkey type "
"of %d)\n", cksumtype, subkey->enctype));
retcode = krb5_c_checksum_length(kcontext, cksumtype, &blocksize);
if (retcode) {
DEBUGMSGTL(("ksm", "Unable to determine checksum length: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
pdu_checksum.length = blocksize;
#else /* MIT_NEW_CRYPTO */
if (ksm_state)
cksumtype = ksm_state->cksumtype;
else
cksumtype = CKSUMTYPE_RSA_MD5_DES;
if (!is_keyed_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a keyed checksum\n",
cksumtype));
snmp_set_detail("Checksum is not a keyed checksum");
retval = SNMPERR_KRB5;
goto error;
}
if (!is_coll_proof_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a collision-proof "
"checksum\n", cksumtype));
snmp_set_detail("Checksum is not a collision-proof checksum");
retval = SNMPERR_KRB5;
goto error;
}
pdu_checksum.length = krb5_checksum_size(kcontext, cksumtype);
pdu_checksum.checksum_type = cksumtype;
#endif /* MIT_NEW_CRYPTO */
/*
* Note that here, we're just leaving blank space for the checksum;
* we remember where that is, and we'll fill it in later.
*/
*offset += pdu_checksum.length;
memset(*wholeMsg + *parms->wholeMsgLen - *offset, 0, pdu_checksum.length);
cksum_pointer = *wholeMsg + *parms->wholeMsgLen - *offset;
rc = asn_realloc_rbuild_header(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
pdu_checksum.length);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_int(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
(long *) &cksumtype,
sizeof(cksumtype));
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_sequence(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_SEQUENCE |
ASN_CONSTRUCTOR),
*offset - seq_offset);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_header(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
*offset - seq_offset);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Security parameter encoding completed\n"));
/*
* We're done with the KSM security parameters - now we do the global
* header and wrap up the whole PDU.
*/
if (*parms->wholeMsgLen < parms->globalDataLen) {
DEBUGMSGTL(("ksm", "Building global data failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
*offset += parms->globalDataLen;
memcpy(*wholeMsg + *parms->wholeMsgLen - *offset,
parms->globalData, parms->globalDataLen);
rc = asn_realloc_rbuild_sequence(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_SEQUENCE |
ASN_CONSTRUCTOR),
*offset);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building master packet sequence.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: PDU master packet encoding complete.\n"));
/*
* Now we need to checksum the entire PDU (since it's built).
*/
pdu_checksum.contents = malloc(pdu_checksum.length);
if (!pdu_checksum.contents) {
DEBUGMSGTL(("ksm", "Unable to malloc %d bytes for checksum\n",
pdu_checksum.length));
retval = SNMPERR_MALLOC;
goto error;
}
/*
* If we didn't encrypt the packet, we haven't yet got the subkey.
* Get that now.
*/
if (!subkey) {
if (ksm_state)
retcode = krb5_auth_con_getremotesubkey(kcontext, auth_context,
&subkey);
else
retcode = krb5_auth_con_getlocalsubkey(kcontext, auth_context,
&subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_auth_con_getlocalsubkey failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
}
#ifdef MIT_NEW_CRYPTO
input.data = (char *) (*wholeMsg + *parms->wholeMsgLen - *offset);
input.length = *offset;
retcode = krb5_c_make_checksum(kcontext, cksumtype, subkey,
KSM_KEY_USAGE_CHECKSUM, &input,
&pdu_checksum);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_calculate_checksum(kcontext, cksumtype, *wholeMsg +
*parms->wholeMsgLen - *offset,
*offset,
(krb5_pointer) subkey->contents,
subkey->length, &pdu_checksum);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "Calculate checksum failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Checksum calculation complete.\n"));
memcpy(cksum_pointer, pdu_checksum.contents, pdu_checksum.length);
DEBUGMSGTL(("ksm", "KSM: Writing checksum of %d bytes at offset %d\n",
pdu_checksum.length, cksum_pointer - (*wholeMsg + 1)));
DEBUGMSGTL(("ksm", "KSM: Checksum:"));
for (i = 0; i < pdu_checksum.length; i++)
DEBUGMSG(("ksm", " %02x",
(unsigned int) pdu_checksum.contents[i]));
DEBUGMSG(("ksm", "\n"));
/*
* If we're _not_ called as part of a response (null ksm_state),
* then save the auth_context for later using our cache routines.
*/
if (!ksm_state) {
if ((retval = ksm_insert_cache(parms->pdu->msgid, auth_context,
(u_char *) parms->secName,
parms->secNameLen)) !=
SNMPERR_SUCCESS)
goto error;
auth_context = NULL;
}
DEBUGMSGTL(("ksm", "KSM processing complete!\n"));
error:
if (pdu_checksum.contents)
#ifdef MIT_NEW_CRYPTO
krb5_free_checksum_contents(kcontext, &pdu_checksum);
#else /* MIT_NEW_CRYPTO */
free(pdu_checksum.contents);
#endif /* MIT_NEW_CRYPTO */
if (ivector.data)
free(ivector.data);
if (subkey)
krb5_free_keyblock(kcontext, subkey);
if (encrypted_data)
free(encrypted_data);
if (cc)
krb5_cc_close(kcontext, cc);
if (auth_context && !ksm_state)
krb5_auth_con_free(kcontext, auth_context);
return retval;
}
