spnego: Support ASN.1 BIT STRING and use it in SPNEGO.

Signed-off-by: Günther Deschner <gd@samba.org>

6 files changed, 61 insertions, 12 deletions

diff --git a/lib/util/asn1.c b/lib/util/asn1.c
index 317ee1314c..70c2c57450 100644
--- a/lib/util/asn1.c
+++ b/lib/util/asn1.c
@@ -205,6 +205,15 @@ bool asn1_write_Integer(struct asn1_data *data, int i)
 	return asn1_pop_tag(data);
 }
 
+/* write a BIT STRING */
+bool asn1_write_BitString(struct asn1_data *data, const void *p, size_t length, uint8_t padding)
+{
+	if (!asn1_push_tag(data, ASN1_BIT_STRING)) return false;
+	if (!asn1_write_uint8(data, padding)) return false;
+	if (!asn1_write(data, p, length)) return false;
+	return asn1_pop_tag(data);
+}
+
 bool ber_write_OID_String(DATA_BLOB *blob, const char *OID)
 {
 	uint_t v, v2;
@@ -727,6 +736,39 @@ bool asn1_read_Integer(struct asn1_data *data, int *i)
 	return asn1_end_tag(data);	
 }
 
+/* read a BIT STRING */
+bool asn1_read_BitString(struct asn1_data *data, TALLOC_CTX *mem_ctx, DATA_BLOB *blob, uint8_t *padding)
+{
+	int len;
+	ZERO_STRUCTP(blob);
+	if (!asn1_start_tag(data, ASN1_BIT_STRING)) return false;
+	len = asn1_tag_remaining(data);
+	if (len < 0) {
+		data->has_error = true;
+		return false;
+	}
+	if (!asn1_read_uint8(data, padding)) return false;
+
+	*blob = data_blob_talloc(mem_ctx, NULL, len);
+	if (!blob->data) {
+		data->has_error = true;
+		return false;
+	}
+	if (asn1_read(data, blob->data, len - 1)) {
+		blob->length--;
+		blob->data[len] = 0;
+		asn1_end_tag(data);
+	}
+
+	if (data->has_error) {
+		data_blob_free(blob);
+		*blob = data_blob_null;
+		*padding = 0;
+		return false;
+	}
+	return true;
+}
+
 /* read an integer */
 bool asn1_read_enumerated(struct asn1_data *data, int *v)
 {
diff --git a/lib/util/asn1.h b/lib/util/asn1.h
index 4c6624056e..9abae50d64 100644
--- a/lib/util/asn1.h
+++ b/lib/util/asn1.h
@@ -60,6 +60,7 @@ bool asn1_push_tag(struct asn1_data *data, uint8_t tag);
 bool asn1_pop_tag(struct asn1_data *data);
 bool asn1_write_implicit_Integer(struct asn1_data *data, int i);
 bool asn1_write_Integer(struct asn1_data *data, int i);
+bool asn1_write_BitString(struct asn1_data *data, const void *p, size_t length, uint8_t padding);
 bool ber_write_OID_String(DATA_BLOB *blob, const char *OID);
 bool asn1_write_OID(struct asn1_data *data, const char *OID);
 bool asn1_write_OctetString(struct asn1_data *data, const void *p, size_t length);
@@ -90,6 +91,7 @@ bool asn1_read_OctetString(struct asn1_data *data, TALLOC_CTX *mem_ctx, DATA_BLO
 bool asn1_read_ContextSimple(struct asn1_data *data, uint8_t num, DATA_BLOB *blob);
 bool asn1_read_implicit_Integer(struct asn1_data *data, int *i);
 bool asn1_read_Integer(struct asn1_data *data, int *i);
+bool asn1_read_BitString(struct asn1_data *data, TALLOC_CTX *mem_ctx, DATA_BLOB *blob, uint8_t *padding);
 bool asn1_read_enumerated(struct asn1_data *data, int *v);
 bool asn1_check_enumerated(struct asn1_data *data, int v);
 bool asn1_write_enumerated(struct asn1_data *data, uint8_t v);
diff --git a/libcli/auth/spnego.h b/libcli/auth/spnego.h
index 08350a44ff..4b60f22d32 100644
--- a/libcli/auth/spnego.h
+++ b/libcli/auth/spnego.h
@@ -32,7 +32,6 @@
 #define SPNEGO_ANON_FLAG     0x10
 #define SPNEGO_CONF_FLAG     0x20
 #define SPNEGO_INTEG_FLAG    0x40
-#define SPNEGO_REQ_FLAG      0x80
 
 enum spnego_negResult {
 	SPNEGO_ACCEPT_COMPLETED = 0,
@@ -43,7 +42,8 @@ enum spnego_negResult {
 
 struct spnego_negTokenInit {
 	const char **mechTypes;
-	int reqFlags;
+	DATA_BLOB reqFlags;
+	uint8_t reqFlagsPadding;
 	DATA_BLOB mechToken;
 	DATA_BLOB mechListMIC;
 	char *targetPrincipal;
diff --git a/libcli/auth/spnego_parse.c b/libcli/auth/spnego_parse.c
index 27e57740dc..3f7047b0e0 100644
--- a/libcli/auth/spnego_parse.c
+++ b/libcli/auth/spnego_parse.c
@@ -62,8 +62,8 @@ static bool read_negTokenInit(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
 		/* Read reqFlags */
 		case ASN1_CONTEXT(1):
 			asn1_start_tag(asn1, ASN1_CONTEXT(1));
-			asn1_read_Integer(asn1, &token->reqFlags);
-			token->reqFlags |= SPNEGO_REQ_FLAG;
+			asn1_read_BitString(asn1, mem_ctx, &token->reqFlags,
+					    &token->reqFlagsPadding);
 			asn1_end_tag(asn1);
 			break;
                 /* Read mechToken */
@@ -130,11 +130,11 @@ static bool write_negTokenInit(struct asn1_data *asn1, struct spnego_negTokenIni
 	}
 
 	/* write reqFlags */
-	if (token->reqFlags & SPNEGO_REQ_FLAG) {
-		int flags = token->reqFlags & ~SPNEGO_REQ_FLAG;
-
+	if (token->reqFlags.length > 0) {
 		asn1_push_tag(asn1, ASN1_CONTEXT(1));
-		asn1_write_Integer(asn1, flags);
+		asn1_write_BitString(asn1, token->reqFlags.data,
+				     token->reqFlags.length,
+				     token->reqFlagsPadding);
 		asn1_pop_tag(asn1);
 	}
 
@@ -353,6 +353,7 @@ bool spnego_free_data(struct spnego_data *spnego)
 		if (spnego->negTokenInit.mechTypes) {
 			talloc_free(spnego->negTokenInit.mechTypes);
 		}
+		data_blob_free(&spnego->negTokenInit.reqFlags);
 		data_blob_free(&spnego->negTokenInit.mechToken);
 		data_blob_free(&spnego->negTokenInit.mechListMIC);
 		talloc_free(spnego->negTokenInit.targetPrincipal);
diff --git a/source3/utils/ntlm_auth.c b/source3/utils/ntlm_auth.c
index a607cb0658..3bdc45a6ef 100644
--- a/source3/utils/ntlm_auth.c
+++ b/source3/utils/ntlm_auth.c
@@ -1454,7 +1454,8 @@ static bool manage_client_ntlmssp_init(struct spnego_data spnego)
 
 	spnego.type = SPNEGO_NEG_TOKEN_INIT;
 	spnego.negTokenInit.mechTypes = my_mechs;
-	spnego.negTokenInit.reqFlags = 0;
+	spnego.negTokenInit.reqFlags = data_blob_null;
+	spnego.negTokenInit.reqFlagsPadding = 0;
 	spnego.negTokenInit.mechListMIC = null_blob;
 
 	status = ntlmssp_update(client_ntlmssp_state, null_blob,
@@ -1609,7 +1610,8 @@ static bool manage_client_krb5_init(struct spnego_data spnego)
 
 	reply.type = SPNEGO_NEG_TOKEN_INIT;
 	reply.negTokenInit.mechTypes = my_mechs;
-	reply.negTokenInit.reqFlags = 0;
+	reply.negTokenInit.reqFlags = data_blob_null;
+	reply.negTokenInit.reqFlagsPadding = 0;
 	reply.negTokenInit.mechToken = tkt;
 	reply.negTokenInit.mechListMIC = data_blob_null;
 
diff --git a/source4/auth/gensec/spnego.c b/source4/auth/gensec/spnego.c
index 8f06eab8bb..977d52ec10 100644
--- a/source4/auth/gensec/spnego.c
+++ b/source4/auth/gensec/spnego.c
@@ -628,7 +628,8 @@ static NTSTATUS gensec_spnego_create_negTokenInit(struct gensec_security *gensec
 
 		/* List the remaining mechs as options */
 		spnego_out.negTokenInit.mechTypes = send_mech_types;
-		spnego_out.negTokenInit.reqFlags = 0;
+		spnego_out.negTokenInit.reqFlags = null_data_blob;
+		spnego_out.negTokenInit.reqFlagsPadding = 0;
 		
 		if (spnego_state->state_position == SPNEGO_SERVER_START) {
 			/* server credentials */
@@ -844,7 +845,8 @@ static NTSTATUS gensec_spnego_update(struct gensec_security *gensec_security, TA
 		/* compose reply */
 		spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 		spnego_out.negTokenInit.mechTypes = my_mechs;
-		spnego_out.negTokenInit.reqFlags = 0;
+		spnego_out.negTokenInit.reqFlags = null_data_blob;
+		spnego_out.negTokenInit.reqFlagsPadding = 0;
 		spnego_out.negTokenInit.mechListMIC = null_data_blob;
 		spnego_out.negTokenInit.mechToken = unwrapped_out;