libcli/auth Move PAC parsing and verification in common.

This uses the source3 PAC code (originally from Samba4) with some
small changes to restore functionality needed by the torture tests,
and to have a common API.

Andrew Bartlett

4 files changed, 28 insertions, 350 deletions

diff --git a/source4/auth/gensec/gensec_krb5.c b/source4/auth/gensec/gensec_krb5.c
index e6497bb9055..c3e3b98f743 100644
--- a/source4/auth/gensec/gensec_krb5.c
+++ b/source4/auth/gensec/gensec_krb5.c
@@ -697,11 +697,11 @@ static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security
 
 		/* decode and verify the pac */
 		nt_status = kerberos_pac_logon_info(gensec_krb5_state, 
-						    &logon_info, pac,
+						    pac,
 						    gensec_krb5_state->smb_krb5_context->krb5_context,
 						    NULL, gensec_krb5_state->keyblock,
 						    client_principal,
-						    gensec_krb5_state->ticket->ticket.authtime, NULL);
+						    gensec_krb5_state->ticket->ticket.authtime, &logon_info);
 
 		if (!NT_STATUS_IS_OK(nt_status)) {
 			free(principal_string);
diff --git a/source4/auth/kerberos/kerberos.h b/source4/auth/kerberos/kerberos.h
index 3f021ad70ac..c712569e5de 100644
--- a/source4/auth/kerberos/kerberos.h
+++ b/source4/auth/kerberos/kerberos.h
@@ -25,6 +25,7 @@
 
 #include "auth/kerberos/krb5_init_context.h"
 #include "librpc/gen_ndr/krb5pac.h"
+#include "libcli/auth/krb5_wrap.h"
 
 struct auth_user_info_dc;
 struct cli_credentials;
@@ -112,24 +113,14 @@ bool kerberos_compatible_enctypes(krb5_context context, krb5_enctype enctype1, k
 void kerberos_free_data_contents(krb5_context context, krb5_data *pdata);
 krb5_error_code smb_krb5_kt_free_entry(krb5_context context, krb5_keytab_entry *kt_entry);
 char *smb_get_krb5_error_message(krb5_context context, krb5_error_code code, TALLOC_CTX *mem_ctx);
-NTSTATUS kerberos_decode_pac(TALLOC_CTX *mem_ctx,
-			     struct PAC_DATA **pac_data_out,
-			     DATA_BLOB blob,
-			     krb5_context context,
-			     const krb5_keyblock *krbtgt_keyblock,
-			     const krb5_keyblock *service_keyblock,
-			     krb5_const_principal client_principal,
-			     time_t tgs_authtime,
-			     krb5_error_code *k5ret);
- NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
-				  struct PAC_LOGON_INFO **logon_info,
-				  DATA_BLOB blob,
-				  krb5_context context,
-				  const krb5_keyblock *krbtgt_keyblock,
-				  const krb5_keyblock *service_keyblock,
-				  krb5_const_principal client_principal,
-				  time_t tgs_authtime, 
-				  krb5_error_code *k5ret);
+NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
+				 DATA_BLOB blob,
+				 krb5_context context,
+				 const krb5_keyblock *krbtgt_keyblock,
+				 const krb5_keyblock *service_keyblock,
+				 krb5_const_principal client_principal,
+				 time_t tgs_authtime,
+				 struct PAC_LOGON_INFO **logon_info);
  krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
 				    struct PAC_DATA *pac_data,
 				    krb5_context context,
diff --git a/source4/auth/kerberos/kerberos_pac.c b/source4/auth/kerberos/kerberos_pac.c
index 07f936ad2ed..5bc80c9a583 100644
--- a/source4/auth/kerberos/kerberos_pac.c
+++ b/source4/auth/kerberos/kerberos_pac.c
@@ -31,334 +31,26 @@
 #include <ldb.h>
 #include "auth/auth_sam_reply.h"
 
-krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
-				   DATA_BLOB pac_data,
-				   struct PAC_SIGNATURE_DATA *sig,
-				   krb5_context context,
-				   const krb5_keyblock *keyblock)
-{
-	krb5_error_code ret;
-	krb5_crypto crypto;
-	Checksum cksum;
-
-	cksum.cksumtype		= (CKSUMTYPE)sig->type;
-	cksum.checksum.length	= sig->signature.length;
-	cksum.checksum.data	= sig->signature.data;
-
-	ret = krb5_crypto_init(context,
-			       keyblock,
-			       0,
-			       &crypto);
-	if (ret) {
-		DEBUG(0,("krb5_crypto_init() failed: %s\n",
-			  smb_get_krb5_error_message(context, ret, mem_ctx)));
-		return ret;
-	}
-	ret = krb5_verify_checksum(context,
-				   crypto,
-				   KRB5_KU_OTHER_CKSUM,
-				   pac_data.data,
-				   pac_data.length,
-				   &cksum);
-	krb5_crypto_destroy(context, crypto);
-
-	return ret;
-}
-
- NTSTATUS kerberos_decode_pac(TALLOC_CTX *mem_ctx,
-			      struct PAC_DATA **pac_data_out,
-			      DATA_BLOB blob,
-			      krb5_context context,
-			      const krb5_keyblock *krbtgt_keyblock,
-			      const krb5_keyblock *service_keyblock,
-			      krb5_const_principal client_principal,
-			      time_t tgs_authtime,
-			      krb5_error_code *k5ret)
-{
-	krb5_error_code ret;
-	NTSTATUS status;
-	enum ndr_err_code ndr_err;
-	struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
-	struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
-	struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
-	struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
-	struct PAC_LOGON_INFO *logon_info = NULL;
-	struct PAC_LOGON_NAME *logon_name = NULL;
-	struct PAC_DATA *pac_data;
-	struct PAC_DATA_RAW *pac_data_raw;
-
-	DATA_BLOB *srv_sig_blob = NULL;
-	DATA_BLOB *kdc_sig_blob = NULL;
-
-	DATA_BLOB modified_pac_blob;
-	NTTIME tgs_authtime_nttime;
-	krb5_principal client_principal_pac;
-	uint32_t i;
-
-	krb5_clear_error_message(context);
-
-	if (k5ret) {
-		*k5ret = KRB5_PARSE_MALFORMED;
-	}
-
-	pac_data = talloc(mem_ctx, struct PAC_DATA);
-	pac_data_raw = talloc(mem_ctx, struct PAC_DATA_RAW);
-	kdc_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
-	srv_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
-	if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
-		if (k5ret) {
-			*k5ret = ENOMEM;
-		}
-		return NT_STATUS_NO_MEMORY;
-	}
-
-	ndr_err = ndr_pull_struct_blob(&blob, pac_data,
-			pac_data, (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		status = ndr_map_error2ntstatus(ndr_err);
-		DEBUG(0,("can't parse the PAC: %s\n",
-			nt_errstr(status)));
-		return status;
-	}
-
-	if (pac_data->num_buffers < 4) {
-		/* we need logon_ingo, service_key and kdc_key */
-		DEBUG(0,("less than 4 PAC buffers\n"));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	ndr_err = ndr_pull_struct_blob(&blob, pac_data_raw,
-				       pac_data_raw,
-				       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		status = ndr_map_error2ntstatus(ndr_err);
-		DEBUG(0,("can't parse the PAC: %s\n",
-			nt_errstr(status)));
-		return status;
-	}
-
-	if (pac_data_raw->num_buffers < 4) {
-		/* we need logon_ingo, service_key and kdc_key */
-		DEBUG(0,("less than 4 PAC buffers\n"));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	if (pac_data->num_buffers != pac_data_raw->num_buffers) {
-		/* we need logon_ingo, service_key and kdc_key */
-		DEBUG(0,("misparse!  PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
-			 pac_data->num_buffers, pac_data_raw->num_buffers));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	for (i=0; i < pac_data->num_buffers; i++) {
-		if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
-			DEBUG(0,("misparse!  PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
-				 i, pac_data->buffers[i].type, pac_data->buffers[i].type));
-			return NT_STATUS_INVALID_PARAMETER;
-		}
-		switch (pac_data->buffers[i].type) {
-			case PAC_TYPE_LOGON_INFO:
-				if (!pac_data->buffers[i].info) {
-					break;
-				}
-				logon_info = pac_data->buffers[i].info->logon_info.info;
-				break;
-			case PAC_TYPE_SRV_CHECKSUM:
-				if (!pac_data->buffers[i].info) {
-					break;
-				}
-				srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
-				srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
-				break;
-			case PAC_TYPE_KDC_CHECKSUM:
-				if (!pac_data->buffers[i].info) {
-					break;
-				}
-				kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
-				kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
-				break;
-			case PAC_TYPE_LOGON_NAME:
-				logon_name = &pac_data->buffers[i].info->logon_name;
-				break;
-			default:
-				break;
-		}
-	}
-
-	if (!logon_info) {
-		DEBUG(0,("PAC no logon_info\n"));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	if (!logon_name) {
-		DEBUG(0,("PAC no logon_name\n"));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	if (!srv_sig_ptr || !srv_sig_blob) {
-		DEBUG(0,("PAC no srv_key\n"));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	if (!kdc_sig_ptr || !kdc_sig_blob) {
-		DEBUG(0,("PAC no kdc_key\n"));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	/* Find and zero out the signatures, as required by the signing algorithm */
-
-	/* We find the data blobs above, now we parse them to get at the exact portion we should zero */
-	ndr_err = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe,
-				       kdc_sig_wipe,
-				       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		status = ndr_map_error2ntstatus(ndr_err);
-		DEBUG(0,("can't parse the KDC signature: %s\n",
-			nt_errstr(status)));
-		return status;
-	}
-
-	ndr_err = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe,
-				       srv_sig_wipe,
-				       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		status = ndr_map_error2ntstatus(ndr_err);
-		DEBUG(0,("can't parse the SRV signature: %s\n",
-			nt_errstr(status)));
-		return status;
-	}
-
-	/* Now zero the decoded structure */
-	memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
-	memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
-
-	/* and reencode, back into the same place it came from */
-	ndr_err = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw,
-				       kdc_sig_wipe,
-				       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		status = ndr_map_error2ntstatus(ndr_err);
-		DEBUG(0,("can't repack the KDC signature: %s\n",
-			nt_errstr(status)));
-		return status;
-	}
-	ndr_err = ndr_push_struct_blob(srv_sig_blob, pac_data_raw,
-				       srv_sig_wipe,
-				       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		status = ndr_map_error2ntstatus(ndr_err);
-		DEBUG(0,("can't repack the SRV signature: %s\n",
-			nt_errstr(status)));
-		return status;
-	}
-
-	/* push out the whole structure, but now with zero'ed signatures */
-	ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw,
-				       pac_data_raw,
-				       (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		status = ndr_map_error2ntstatus(ndr_err);
-		DEBUG(0,("can't repack the RAW PAC: %s\n",
-			nt_errstr(status)));
-		return status;
-	}
-
-	/* verify by service_key */
-	ret = check_pac_checksum(mem_ctx,
-				 modified_pac_blob, srv_sig_ptr,
-				 context,
-				 service_keyblock);
-	if (ret) {
-		DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
-			  smb_get_krb5_error_message(context, ret, mem_ctx)));
-		if (k5ret) {
-			*k5ret = ret;
-		}
-		return NT_STATUS_ACCESS_DENIED;
-	}
-
-	if (krbtgt_keyblock) {
-		ret = check_pac_checksum(mem_ctx,
-					    srv_sig_ptr->signature, kdc_sig_ptr,
-					    context, krbtgt_keyblock);
-		if (ret) {
-			DEBUG(1, ("PAC Decode: Failed to verify the KDC signature: %s\n",
-				  smb_get_krb5_error_message(context, ret, mem_ctx)));
-			if (k5ret) {
-				*k5ret = ret;
-			}
-			return NT_STATUS_ACCESS_DENIED;
-		}
-	}
-
-	/* Convert to NT time, so as not to loose accuracy in comparison */
-	unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
-
-	if (tgs_authtime_nttime != logon_name->logon_time) {
-		DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
-		DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
-		DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
-		return NT_STATUS_ACCESS_DENIED;
-	}
-
-	ret = krb5_parse_name_flags(context, logon_name->account_name, KRB5_PRINCIPAL_PARSE_NO_REALM,
-				    &client_principal_pac);
-	if (ret) {
-		DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
-			  logon_name->account_name,
-			  smb_get_krb5_error_message(context, ret, mem_ctx)));
-		if (k5ret) {
-			*k5ret = ret;
-		}
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	if (!krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
-		DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
-			  logon_name->account_name));
-		krb5_free_principal(context, client_principal_pac);
-		return NT_STATUS_ACCESS_DENIED;
-	}
-
-	krb5_free_principal(context, client_principal_pac);
-
-#if 0
-	if (strcasecmp(logon_info->info3.base.account_name.string,
-		       "Administrator")== 0) {
-		file_save("tmp_pac_data-admin.dat",blob.data,blob.length);
-	}
-#endif
-
-	DEBUG(3,("Found account name from PAC: %s [%s]\n",
-		 logon_info->info3.base.account_name.string,
-		 logon_info->info3.base.full_name.string));
-	*pac_data_out = pac_data;
-
-	return NT_STATUS_OK;
-}
-
 _PUBLIC_  NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
-				  struct PAC_LOGON_INFO **logon_info,
-				  DATA_BLOB blob,
-				  krb5_context context,
-				  const krb5_keyblock *krbtgt_keyblock,
-				  const krb5_keyblock *service_keyblock,
-				  krb5_const_principal client_principal,
-				  time_t tgs_authtime,
-				  krb5_error_code *k5ret)
+					   DATA_BLOB blob,
+					   krb5_context context,
+					   const krb5_keyblock *krbtgt_keyblock,
+					   const krb5_keyblock *service_keyblock,
+					   krb5_const_principal client_principal,
+					   time_t tgs_authtime,
+					   struct PAC_LOGON_INFO **logon_info)
 {
 	NTSTATUS nt_status;
 	struct PAC_DATA *pac_data;
 	int i;
 	nt_status = kerberos_decode_pac(mem_ctx,
-					&pac_data,
 					blob,
 					context,
 					krbtgt_keyblock,
 					service_keyblock,
 					client_principal,
 					tgs_authtime,
-					k5ret);
+					&pac_data);
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		return nt_status;
 	}
diff --git a/source4/torture/auth/pac.c b/source4/torture/auth/pac.c
index 4a306131ccf..f09e039964e 100644
--- a/source4/torture/auth/pac.c
+++ b/source4/torture/auth/pac.c
@@ -142,13 +142,13 @@ static bool torture_pac_self_check(struct torture_context *tctx)
 
 	/* Now check that we can read it back (using full decode and validate) */
 	nt_status = kerberos_decode_pac(mem_ctx, 
-					&pac_data,
 					tmp_blob,
 					smb_krb5_context->krb5_context,
 					&krbtgt_keyblock,
 					&server_keyblock,
 					client_principal, 
-					logon_time, NULL);
+					logon_time,
+ 					&pac_data);
 
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, 
@@ -189,14 +189,13 @@ static bool torture_pac_self_check(struct torture_context *tctx)
 
 	/* Now check that we can read it back (yet again) */
 	nt_status = kerberos_pac_logon_info(mem_ctx, 
-					    &logon_info,
 					    tmp_blob,
 					    smb_krb5_context->krb5_context,
 					    &krbtgt_keyblock,
 					    &server_keyblock,
 					    client_principal, 
 					    logon_time, 
-					    NULL);
+					    &logon_info);
 	
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, 
@@ -408,12 +407,11 @@ static bool torture_pac_saved_check(struct torture_context *tctx)
 
 	/* Decode and verify the signaure on the PAC */
 	nt_status = kerberos_decode_pac(mem_ctx, 
-					&pac_data,
 					tmp_blob,
 					smb_krb5_context->krb5_context,
 					krbtgt_keyblock_p,
 					&server_keyblock, 
-					client_principal, authtime, NULL);
+					client_principal, authtime, &pac_data);
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, 
 					    krbtgt_keyblock_p);
@@ -466,12 +464,11 @@ static bool torture_pac_saved_check(struct torture_context *tctx)
 
 	/* Parse the PAC again, for the logon info this time (using Samba4's parsing) */
 	nt_status = kerberos_pac_logon_info(mem_ctx, 
-					    &logon_info,
 					    tmp_blob,
 					    smb_krb5_context->krb5_context,
 					    krbtgt_keyblock_p,
 					    &server_keyblock,
-					    client_principal, authtime, NULL);
+					    client_principal, authtime, &logon_info);
 
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, 
@@ -654,13 +651,12 @@ static bool torture_pac_saved_check(struct torture_context *tctx)
 
 	/* Break the auth time, to ensure we check this vital detail (not setting this caused all the pain in the first place... */
 	nt_status = kerberos_decode_pac(mem_ctx, 
-					&pac_data,
 					tmp_blob,
 					smb_krb5_context->krb5_context,
 					krbtgt_keyblock_p,
 					&server_keyblock,
 					client_principal, 
-					authtime + 1, NULL);
+					authtime + 1, &pac_data);
 	if (NT_STATUS_IS_OK(nt_status)) {
 
 		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, 
@@ -691,13 +687,12 @@ static bool torture_pac_saved_check(struct torture_context *tctx)
 	}
 
 	nt_status = kerberos_decode_pac(mem_ctx, 
-					&pac_data,
 					tmp_blob,
 					smb_krb5_context->krb5_context,
 					krbtgt_keyblock_p,
 					&server_keyblock,
 					client_principal, 
-					authtime, NULL);
+					authtime, &pac_data);
 	if (NT_STATUS_IS_OK(nt_status)) {
 		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, 
 					    krbtgt_keyblock_p);
@@ -710,13 +705,13 @@ static bool torture_pac_saved_check(struct torture_context *tctx)
 	tmp_blob.data[tmp_blob.length - 2]++;
 
 	nt_status = kerberos_decode_pac(mem_ctx, 
-					&pac_data,
 					tmp_blob,
 					smb_krb5_context->krb5_context,
 					krbtgt_keyblock_p,
 					&server_keyblock,
 					client_principal, 
-					authtime, NULL);
+					authtime,
+					&pac_data);
 	if (NT_STATUS_IS_OK(nt_status)) {
 		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, 
 					    krbtgt_keyblock_p);