static bool read_negTokenTarg(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
struct spnego_negTokenTarg *token)
{
ZERO_STRUCTP(token);
asn1_start_tag(asn1, ASN1_CONTEXT(1));
asn1_start_tag(asn1, ASN1_SEQUENCE(0));
while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
uint8_t context;
char *oid;
if (!asn1_peek_uint8(asn1, &context)) {
asn1->has_error = true;
break;
}
switch (context) {
case ASN1_CONTEXT(0):
asn1_start_tag(asn1, ASN1_CONTEXT(0));
asn1_start_tag(asn1, ASN1_ENUMERATED);
asn1_read_uint8(asn1, &token->negResult);
asn1_end_tag(asn1);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(1):
asn1_start_tag(asn1, ASN1_CONTEXT(1));
asn1_read_OID(asn1, mem_ctx, &oid);
token->supportedMech = oid;
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(2):
asn1_start_tag(asn1, ASN1_CONTEXT(2));
asn1_read_OctetString(asn1, mem_ctx, &token->responseToken);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(3):
asn1_start_tag(asn1, ASN1_CONTEXT(3));
asn1_read_OctetString(asn1, mem_ctx, &token->mechListMIC);
asn1_end_tag(asn1);
break;
default:
asn1->has_error = true;
break;
}
}
asn1_end_tag(asn1);
asn1_end_tag(asn1);
return !asn1->has_error;
}
static bool read_negTokenTarg(ASN1_DATA *asn1, negTokenTarg_t *token)
{
ZERO_STRUCTP(token);
asn1_start_tag(asn1, ASN1_CONTEXT(1));
asn1_start_tag(asn1, ASN1_SEQUENCE(0));
while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
switch (asn1->data[asn1->ofs]) {
case ASN1_CONTEXT(0):
asn1_start_tag(asn1, ASN1_CONTEXT(0));
asn1_start_tag(asn1, ASN1_ENUMERATED);
asn1_read_uint8(asn1, &token->negResult);
asn1_end_tag(asn1);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(1):
asn1_start_tag(asn1, ASN1_CONTEXT(1));
asn1_read_OID(asn1, &token->supportedMech);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(2):
asn1_start_tag(asn1, ASN1_CONTEXT(2));
asn1_read_OctetString(asn1, &token->responseToken);
asn1_end_tag(asn1);
break;
case ASN1_CONTEXT(3):
asn1_start_tag(asn1, ASN1_CONTEXT(3));
asn1_read_OctetString(asn1, &token->mechListMIC);
asn1_end_tag(asn1);
break;
default:
asn1->has_error = True;
break;
}
}
asn1_end_tag(asn1);
asn1_end_tag(asn1);
return !asn1->has_error;
}
/*
parse a negTokenInit packet giving a GUID, a list of supported
OIDs (the mechanisms) and a principal name string
*/
bool spnego_parse_negTokenInit(TALLOC_CTX *ctx,
DATA_BLOB blob,
char *OIDs[ASN1_MAX_OIDS],
char **principal,
DATA_BLOB *secblob)
{
int i;
bool ret;
ASN1_DATA *data;
data = asn1_init(talloc_tos());
if (data == NULL) {
return false;
}
asn1_load(data, blob);
asn1_start_tag(data,ASN1_APPLICATION(0));
asn1_check_OID(data,OID_SPNEGO);
/* negTokenInit [0] NegTokenInit */
asn1_start_tag(data,ASN1_CONTEXT(0));
asn1_start_tag(data,ASN1_SEQUENCE(0));
/* mechTypes [0] MechTypeList OPTIONAL */
/* Not really optional, we depend on this to decide
* what mechanisms we have to work with. */
asn1_start_tag(data,ASN1_CONTEXT(0));
asn1_start_tag(data,ASN1_SEQUENCE(0));
for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
asn1_read_OID(data,ctx, &OIDs[i]);
if (data->has_error) {
break;
}
}
OIDs[i] = NULL;
asn1_end_tag(data);
asn1_end_tag(data);
if (principal) {
*principal = NULL;
}
if (secblob) {
*secblob = data_blob_null;
}
/*
Win7 + Live Sign-in Assistant attaches a mechToken
ASN1_CONTEXT(2) to the negTokenInit packet
which breaks our negotiation if we just assume
the next tag is ASN1_CONTEXT(3).
*/
if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
uint8 flags;
/* reqFlags [1] ContextFlags OPTIONAL */
asn1_start_tag(data, ASN1_CONTEXT(1));
asn1_start_tag(data, ASN1_BIT_STRING);
while (asn1_tag_remaining(data) > 0) {
asn1_read_uint8(data, &flags);
}
asn1_end_tag(data);
asn1_end_tag(data);
}
if (asn1_peek_tag(data, ASN1_CONTEXT(2))) {
DATA_BLOB sblob = data_blob_null;
/* mechToken [2] OCTET STRING OPTIONAL */
asn1_start_tag(data, ASN1_CONTEXT(2));
asn1_read_OctetString(data, ctx, &sblob);
asn1_end_tag(data);
if (secblob) {
*secblob = sblob;
} else {
data_blob_free(&sblob);
}
}
if (asn1_peek_tag(data, ASN1_CONTEXT(3))) {
char *princ = NULL;
/* mechListMIC [3] OCTET STRING OPTIONAL */
asn1_start_tag(data, ASN1_CONTEXT(3));
asn1_start_tag(data, ASN1_SEQUENCE(0));
asn1_start_tag(data, ASN1_CONTEXT(0));
asn1_read_GeneralString(data, ctx, &princ);
asn1_end_tag(data);
asn1_end_tag(data);
asn1_end_tag(data);
if (principal) {
*principal = princ;
} else {
TALLOC_FREE(princ);
}
}
asn1_end_tag(data);
asn1_end_tag(data);
asn1_end_tag(data);
ret = !data->has_error;
if (data->has_error) {
int j;
if (principal) {
TALLOC_FREE(*principal);
}
if (secblob) {
data_blob_free(secblob);
}
for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
TALLOC_FREE(OIDs[j]);
}
}
asn1_free(data);
return ret;
}
