diff --git a/lib/krb5/context.c b/lib/krb5/context.c
index 071b2a8c1..c4fe5a63c 100644
--- a/lib/krb5/context.c
+++ b/lib/krb5/context.c
@@ -240,6 +240,7 @@ init_context_from_config_file(krb5_context context)
     INIT_FLAG(context, flags, KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME, TRUE, "dns_canonicalize_hostname");
     INIT_FLAG(context, flags, KRB5_CTX_F_CHECK_PAC, TRUE, "check_pac");
     INIT_FLAG(context, flags, KRB5_CTX_F_ENFORCE_OK_AS_DELEGATE, FALSE, "enforce_ok_as_delegate");
+    INIT_FLAG(context, flags, KRB5_CTX_F_REPORT_CANONICAL_CLIENT_NAME, FALSE, "report_canonical_client_name");
 
     if (context->default_cc_name)
 	free(context->default_cc_name);
diff --git a/lib/krb5/krb5.conf.5 b/lib/krb5/krb5.conf.5
index bb2e61d88..0a0fab071 100644
--- a/lib/krb5/krb5.conf.5
+++ b/lib/krb5/krb5.conf.5
@@ -518,6 +518,9 @@ If this flag is true, then all application protocol authentication
 requests will be flagged to indicate that the application supports
 channel bindings when operating over a secure channel.
 The default value is false.
+.It Li report_canonical_client_name = Va boolean
+If this flag is true, then the canonical client name from the PAC will
+be used instead of the client name in the ticket. The default value is false.
 .El
 .It Li [domain_realm]
 This is a list of mappings from DNS domain to Kerberos realm.
diff --git a/lib/krb5/krb5_locl.h b/lib/krb5/krb5_locl.h
index b2a53a55f..eca434fd5 100644
--- a/lib/krb5/krb5_locl.h
+++ b/lib/krb5/krb5_locl.h
@@ -328,6 +328,7 @@ typedef struct krb5_context_data {
 #define KRB5_CTX_F_RD_REQ_IGNORE		16
 #define KRB5_CTX_F_FCACHE_STRICT_CHECKING	32
 #define KRB5_CTX_F_ENFORCE_OK_AS_DELEGATE	64
+#define KRB5_CTX_F_REPORT_CANONICAL_CLIENT_NAME	128
     struct send_to_kdc *send_to_kdc;
 #ifdef PKINIT
     hx509_context hx509ctx;
diff --git a/lib/krb5/libkrb5-exports.def.in b/lib/krb5/libkrb5-exports.def.in
index 90212173e..5cc5fe97c 100644
--- a/lib/krb5/libkrb5-exports.def.in
+++ b/lib/krb5/libkrb5-exports.def.in
@@ -822,6 +822,7 @@ EXPORTS
 	_krb5_get_int
         _krb5_get_int64
 	_krb5_pac_sign
+	_krb5_pac_get_canon_principal
 	_krb5_kdc_pac_sign_ticket
 	_krb5_kdc_pac_ticket_parse
 	_kdc_tkt_insert_pac
diff --git a/lib/krb5/pac.c b/lib/krb5/pac.c
index 30dbd400e..130e9a098 100644
--- a/lib/krb5/pac.c
+++ b/lib/krb5/pac.c
@@ -53,8 +53,15 @@ struct krb5_pac_data {
     struct PAC_INFO_BUFFER *server_checksum;
     struct PAC_INFO_BUFFER *privsvr_checksum;
     struct PAC_INFO_BUFFER *logon_name;
+    struct PAC_INFO_BUFFER *upn_dns_info;
     struct PAC_INFO_BUFFER *ticket_checksum;
     krb5_data ticket_sign_data;
+
+    /* parsed upn_dns_info, krb5_pac_verify only */
+    krb5_principal upn_princ;
+    uint32_t upn_flags;
+    krb5_principal canon_princ;
+    krb5_data sid;
 };
 
 #define PAC_ALIGNMENT			8
@@ -66,8 +73,13 @@ struct krb5_pac_data {
 #define PAC_PRIVSVR_CHECKSUM		7
 #define PAC_LOGON_NAME			10
 #define PAC_CONSTRAINED_DELEGATION	11
+#define PAC_UPN_DNS_INFO		12
 #define PAC_TICKET_CHECKSUM		16
 
+/* Flag in PAC_UPN_DNS_INFO, _krb5_pac_get_upn_dns_info() */
+#define PAC_EXTRA_LOGON_INFO_FLAGS_UPN_DEFAULTED	0x1
+#define PAC_EXTRA_LOGON_INFO_FLAGS_HAS_SAM_NAME_AND_SID	0x2
+
 #define CHECK(r,f,l)						\
 	do {							\
 		if (((r) = f ) != 0) {				\
@@ -242,6 +254,14 @@ krb5_pac_parse(krb5_context context, const void *ptr, size_t len,
 		goto out;
 	    }
 	    p->logon_name = &p->pac->buffers[i];
+	} else if (p->pac->buffers[i].type == PAC_UPN_DNS_INFO) {
+	    if (p->upn_dns_info) {
+		ret = EINVAL;
+		krb5_set_error_message(context, ret,
+				       N_("PAC has multiple UPN DNS info buffers", ""));
+		goto out;
+	    }
+	    p->upn_dns_info = &p->pac->buffers[i];
 	} else if (p->pac->buffers[i].type == PAC_TICKET_CHECKSUM) {
 	    if (p->ticket_checksum) {
 		ret = EINVAL;
@@ -445,6 +465,11 @@ krb5_pac_free(krb5_context context, krb5_pac pac)
 	return;
     krb5_data_free(&pac->data);
     krb5_data_free(&pac->ticket_sign_data);
+
+    krb5_free_principal(context, pac->upn_princ);
+    krb5_free_principal(context, pac->canon_princ);
+    krb5_data_free(&pac->sid);
+
     free(pac->pac);
     free(pac);
 }
@@ -604,6 +629,185 @@ create_checksum(krb5_context context,
     return 0;
 }
 
+static krb5_error_code
+parse_upn_dns_info(krb5_context context,
+		   const struct PAC_INFO_BUFFER *upndnsinfo,
+		   const krb5_data *data,
+		   krb5_principal *upn_princ,
+		   uint32_t *flags,
+		   krb5_principal *sam_name_princ,
+		   krb5_data *sid)
+{
+    krb5_error_code ret;
+    krb5_storage *sp = NULL;
+    uint16_t upn_length, upn_offset;
+    uint16_t dns_domain_name_length, dns_domain_name_offset;
+    uint16_t sam_name_length, sam_name_offset;
+    uint16_t sid_length, sid_offset;
+    char *upn = NULL;
+    char *dns_domain_name = NULL;
+    char *sam_name = NULL;
+
+    *upn_princ = NULL;
+    *flags = 0;
+    *sam_name_princ = NULL;
+    krb5_data_zero(sid);
+
+    sp = krb5_storage_from_readonly_mem((const char *)data->data + upndnsinfo->offset_lo,
+					upndnsinfo->buffersize);
+    if (sp == NULL)
+	return krb5_enomem(context);
+
+    krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);
+
+    CHECK(ret, krb5_ret_uint16(sp, &upn_length), out);
+    CHECK(ret, krb5_ret_uint16(sp, &upn_offset), out);
+    CHECK(ret, krb5_ret_uint16(sp, &dns_domain_name_length), out);
+    CHECK(ret, krb5_ret_uint16(sp, &dns_domain_name_offset), out);
+    CHECK(ret, krb5_ret_uint32(sp, flags), out);
+
+    if (*flags & PAC_EXTRA_LOGON_INFO_FLAGS_HAS_SAM_NAME_AND_SID) {
+	CHECK(ret, krb5_ret_uint16(sp, &sam_name_length), out);
+	CHECK(ret, krb5_ret_uint16(sp, &sam_name_offset), out);
+	CHECK(ret, krb5_ret_uint16(sp, &sid_length), out);
+	CHECK(ret, krb5_ret_uint16(sp, &sid_offset), out);
+    }
+
+    CHECK(ret, _krb5_ret_utf8_from_ucs2le_at_offset(sp, upn_offset,
+						    upn_length, &upn), out);
+    CHECK(ret, _krb5_ret_utf8_from_ucs2le_at_offset(sp, dns_domain_name_offset,
+						    dns_domain_name_length, &dns_domain_name), out);
+    if (*flags & PAC_EXTRA_LOGON_INFO_FLAGS_HAS_SAM_NAME_AND_SID) {
+	CHECK(ret, _krb5_ret_utf8_from_ucs2le_at_offset(sp, sam_name_offset,
+							sam_name_length, &sam_name), out);
+    }
+
+    if (upn_length) {
+	ret = krb5_parse_name_flags(context,
+				    upn,
+				    KRB5_PRINCIPAL_PARSE_ENTERPRISE |
+				    KRB5_PRINCIPAL_PARSE_NO_DEF_REALM,
+				    upn_princ);
+	if (ret)
+	    goto out;
+
+	ret = krb5_principal_set_realm(context, *upn_princ, dns_domain_name);
+	if (ret)
+	    goto out;
+    }
+
+    if (*flags & PAC_EXTRA_LOGON_INFO_FLAGS_HAS_SAM_NAME_AND_SID) {
+	ret = krb5_parse_name_flags(context,
+				    sam_name,
+				    KRB5_PRINCIPAL_PARSE_NO_REALM |
+				    KRB5_PRINCIPAL_PARSE_NO_DEF_REALM,
+				    sam_name_princ);
+	if (ret)
+	    goto out;
+
+	ret = krb5_principal_set_realm(context, *sam_name_princ, dns_domain_name);
+	if (ret)
+	    goto out;
+
+	CHECK(ret, _krb5_ret_data_at_offset(sp, sid_offset, sid_length, sid), out);
+    }
+
+out:
+    free(upn);
+    free(dns_domain_name);
+    free(sam_name);
+
+    krb5_storage_free(sp);
+    return ret;
+}
+
+#define UPN_DNS_INFO_EX_LENGTH	20
+
+static krb5_error_code
+build_upn_dns_info(krb5_context context,
+		   krb5_const_principal upn_princ,
+		   krb5_const_principal canon_princ,
+		   krb5_data *upn_dns_info)
+{
+    krb5_error_code ret;
+    krb5_storage *sp = NULL;
+    char *upn_princ_name = NULL;
+    char *canon_princ_name = NULL;
+    uint32_t flags;
+    krb5_const_realm realm;
+
+    sp = krb5_storage_emem();
+    if (sp == NULL) {
+	ret = krb5_enomem(context);
+	goto out;
+    }
+
+    krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);
+
+    if (upn_princ) {
+	ret = krb5_unparse_name_flags(context, upn_princ,
+				      KRB5_PRINCIPAL_UNPARSE_DISPLAY,
+				      &upn_princ_name);
+	if (ret)
+	    goto out;
+    }
+
+    ret = krb5_storage_truncate(sp, UPN_DNS_INFO_EX_LENGTH);
+    if (ret)
+	goto out;
+
+    ret = _krb5_store_utf8_as_ucs2le_at_offset(sp, (off_t)-1, upn_princ_name);
+    if (ret)
+	goto out;
+
+    if (canon_princ) {
+	ret = krb5_unparse_name_flags(context, canon_princ,
+				      KRB5_PRINCIPAL_UNPARSE_NO_REALM |
+				      KRB5_PRINCIPAL_UNPARSE_DISPLAY,
+				      &canon_princ_name);
+	if (ret)
+	    goto out;
+    }
+
+    if (canon_princ)
+	realm = canon_princ->realm;
+    else if (upn_princ)
+	realm = upn_princ->realm;
+    else
+	realm = NULL;
+
+    ret = _krb5_store_utf8_as_ucs2le_at_offset(sp, (off_t)-1, realm);
+    if (ret)
+	goto out;
+
+    flags = 0;
+    if (upn_princ)
+	flags |= PAC_EXTRA_LOGON_INFO_FLAGS_UPN_DEFAULTED;
+    if (canon_princ)
+	flags |= PAC_EXTRA_LOGON_INFO_FLAGS_HAS_SAM_NAME_AND_SID;
+
+    ret = krb5_store_uint32(sp, flags);
+    if (ret)
+	goto out;
+
+    ret = _krb5_store_utf8_as_ucs2le_at_offset(sp, (off_t)-1,
+					       canon_princ_name);
+    if (ret)
+	goto out;
+
+    ret = krb5_storage_to_data(sp, upn_dns_info);
+    if (ret)
+	goto out;
+
+out:
+    if (ret)
+	krb5_data_free(upn_dns_info);
+
+    krb5_xfree(canon_princ_name);
+    krb5_xfree(upn_princ_name);
+
+    return ret;
+}
 
 /*
  *
@@ -628,7 +832,7 @@ verify_logonname(krb5_context context,
 {
     krb5_error_code ret;
     uint32_t time1, time2;
-    krb5_storage *sp;
+    krb5_storage *sp = NULL;
     uint16_t len;
     char *s = NULL;
     char *principal_string = NULL;
@@ -734,6 +938,7 @@ verify_logonname(krb5_context context,
     free(principal_string);
     return ret;
 out:
+    krb5_storage_free(sp);
     return ret;
 }
 
@@ -949,6 +1154,20 @@ krb5_pac_verify(krb5_context context,
 	}
     }
 
+    if (pac->upn_dns_info &&
+	pac->upn_princ == NULL && pac->canon_princ == NULL && pac->sid.data == NULL) {
+	ret = parse_upn_dns_info(context, pac->upn_dns_info, &pac->data,
+				 &pac->upn_princ, &pac->upn_flags,
+				 &pac->canon_princ, &pac->sid);
+	if (ret)
+	    return ret;
+
+	if (pac->canon_princ &&
+	    !krb5_realm_compare(context, principal, pac->canon_princ)) {
+	    return KRB5KRB_AP_ERR_MODIFIED;
+	}
+    }
+
     return 0;
 }
 
@@ -1012,10 +1231,12 @@ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 _krb5_pac_sign(krb5_context context,
 	       krb5_pac p,
 	       time_t authtime,
-	       krb5_principal principal,
+	       krb5_const_principal principal,
 	       const krb5_keyblock *server_key,
 	       const krb5_keyblock *priv_key,
 	       uint16_t rodc_id,
+	       krb5_const_principal upn_princ,
+	       krb5_const_principal canon_princ,
 	       krb5_data *data)
 {
     krb5_error_code ret;
@@ -1027,9 +1248,11 @@ _krb5_pac_sign(krb5_context context,
     int num = 0;
     size_t i, sz;
     krb5_data logon, d;
+    krb5_data upn_dns_info;
 
     krb5_data_zero(&d);
     krb5_data_zero(&logon);
+    krb5_data_zero(&upn_dns_info);
 
     for (i = 0; i < p->pac->numbuffers; i++) {
 	if (p->pac->buffers[i].type == PAC_SERVER_CHECKSUM) {
@@ -1062,6 +1285,16 @@ _krb5_pac_sign(krb5_context context,
 				       N_("PAC has multiple logon names", ""));
 		goto out;
 	    }
+	} else if (p->pac->buffers[i].type == PAC_UPN_DNS_INFO) {
+	    if (p->upn_dns_info == NULL) {
+		p->upn_dns_info = &p->pac->buffers[i];
+	    }
+	    if (p->upn_dns_info != &p->pac->buffers[i]) {
+		ret = KRB5KDC_ERR_BADOPTION;
+		krb5_set_error_message(context, ret,
+				       N_("PAC has multiple UPN DNS info buffers", ""));
+		goto out;
+	    }
 	} else if (p->pac->buffers[i].type == PAC_TICKET_CHECKSUM) {
 	    if (p->ticket_checksum == NULL) {
 		p->ticket_checksum = &p->pac->buffers[i];
@@ -1081,6 +1314,8 @@ _krb5_pac_sign(krb5_context context,
 	num++;
     if (p->privsvr_checksum == NULL)
 	num++;
+    if ((upn_princ || canon_princ) && p->upn_dns_info == NULL)
+	num++;
     if (p->ticket_sign_data.length != 0 && p->ticket_checksum == NULL)
 	num++;
 
@@ -1110,9 +1345,14 @@ _krb5_pac_sign(krb5_context context,
 	    memset(p->privsvr_checksum, 0, sizeof(*p->privsvr_checksum));
 	    p->privsvr_checksum->type = PAC_PRIVSVR_CHECKSUM;
 	}
+	if ((upn_princ || canon_princ) && p->upn_dns_info == NULL) {
+	    p->upn_dns_info = &p->pac->buffers[p->pac->numbuffers++];
+	    memset(p->upn_dns_info, 0, sizeof(*p->upn_dns_info));
+	    p->upn_dns_info->type = PAC_UPN_DNS_INFO;
+	}
 	if (p->ticket_sign_data.length != 0 && p->ticket_checksum == NULL) {
 	    p->ticket_checksum = &p->pac->buffers[p->pac->numbuffers++];
-	    memset(p->ticket_checksum, 0, sizeof(*p->privsvr_checksum));
+	    memset(p->ticket_checksum, 0, sizeof(*p->ticket_checksum));
 	    p->ticket_checksum->type = PAC_TICKET_CHECKSUM;
 	}
     }
@@ -1127,6 +1367,9 @@ _krb5_pac_sign(krb5_context context,
     if (ret == 0)
         ret = pac_checksum(context, priv_key, &priv_cksumtype, &priv_size);
 
+    if (upn_princ || canon_princ)
+	ret = build_upn_dns_info(context, upn_princ, canon_princ, &upn_dns_info);
+
     /* Encode PAC */
     if (ret == 0) {
         sp = krb5_storage_emem();
@@ -1190,6 +1433,13 @@ _krb5_pac_sign(krb5_context context,
 		ret = KRB5KDC_ERR_BADOPTION;
 		goto out;
 	    }
+	} else if ((upn_princ || canon_princ) &&
+		   p->pac->buffers[i].type == PAC_UPN_DNS_INFO) {
+	    len = krb5_storage_write(spdata, upn_dns_info.data, upn_dns_info.length);
+	    if (upn_dns_info.length != len) {
+		ret = KRB5KDC_ERR_BADOPTION;
+		goto out;
+	    }
 	} else {
 	    len = p->pac->buffers[i].buffersize;
 	    ptr = (char *)p->data.data + p->pac->buffers[i].offset_lo;
@@ -1279,6 +1529,7 @@ _krb5_pac_sign(krb5_context context,
     *data = d;
 
     krb5_data_free(&logon);
+    krb5_data_free(&upn_dns_info);
     krb5_storage_free(sp);
     krb5_storage_free(spdata);
 
@@ -1286,6 +1537,7 @@ _krb5_pac_sign(krb5_context context,
 out:
     krb5_data_free(&d);
     krb5_data_free(&logon);
+    krb5_data_free(&upn_dns_info);
     if (sp)
 	krb5_storage_free(sp);
     if (spdata)
@@ -1347,6 +1599,20 @@ out:
     return ret;
 }
 
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+_krb5_pac_get_canon_principal(krb5_context context,
+			      krb5_pac pac,
+			      krb5_principal *canon_princ)
+{
+    *canon_princ = NULL;
+
+    if (pac->canon_princ == NULL)
+	return ENOENT;
+
+    return krb5_copy_principal(context, pac->canon_princ, canon_princ);
+}
+
 static unsigned char single_zero = '\0';
 static krb5_data single_zero_pac = { 1, &single_zero };
 
@@ -1470,12 +1736,14 @@ out:
 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 _krb5_kdc_pac_sign_ticket(krb5_context context,
 			  const krb5_pac pac,
-			  krb5_principal client,
+			  krb5_const_principal client,
 			  const krb5_keyblock *server_key,
 			  const krb5_keyblock *kdc_key,
 			  uint16_t rodc_id,
 			  krb5_boolean add_ticket_sig,
-			  EncTicketPart *tkt)
+			  EncTicketPart *tkt,
+			  krb5_const_principal upn,
+			  krb5_const_principal canon_name)
 {
     krb5_error_code ret;
     krb5_data tkt_data;
@@ -1510,7 +1778,7 @@ _krb5_kdc_pac_sign_ticket(krb5_context context,
     }
 
     ret = _krb5_pac_sign(context, pac, tkt->authtime, client, server_key,
-			 kdc_key, rodc_id, &rspac);
+			 kdc_key, rodc_id, upn, canon_name, &rspac);
     if (ret == 0)
         ret = _kdc_tkt_insert_pac(context, tkt, &rspac);
     krb5_data_free(&rspac);
diff --git a/lib/krb5/rd_req.c b/lib/krb5/rd_req.c
index 58ff04568..bd0b68b9c 100644
--- a/lib/krb5/rd_req.c
+++ b/lib/krb5/rd_req.c
@@ -1042,6 +1042,17 @@ krb5_rd_req_ctx(krb5_context context,
 				  o->ticket->client,
 				  o->keyblock,
 				  NULL);
+	    if (ret == 0 && (context->flags & KRB5_CTX_F_REPORT_CANONICAL_CLIENT_NAME)) {
+		krb5_error_code ret2;
+		krb5_principal canon_name;
+
+		ret2 = _krb5_pac_get_canon_principal(context, pac, &canon_name);
+		if (ret2 == 0) {
+		    krb5_free_principal(context, o->ticket->client);
+		    o->ticket->client = canon_name;
+		} else if (ret2 != ENOENT)
+		    ret = ret2;
+	    }
 	    krb5_pac_free(context, pac);
 	    if (ret)
 		goto out;
diff --git a/lib/krb5/store.c b/lib/krb5/store.c
index 2cb42c9a0..e3e4aa8b8 100644
--- a/lib/krb5/store.c
+++ b/lib/krb5/store.c
@@ -1823,3 +1823,99 @@ cleanup:
     }
     return ret;
 }
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+_krb5_ret_data_at_offset(krb5_storage *sp,
+			 size_t offset,
+			 size_t length,
+			 krb5_data *data)
+{
+    krb5_error_code ret;
+    off_t cur, size;
+
+    krb5_data_zero(data);
+
+    cur = sp->seek(sp, 0, SEEK_CUR);
+    if (cur < 0)
+	return HEIM_ERR_NOT_SEEKABLE;
+
+    size = sp->seek(sp, 0, SEEK_END);
+    if (offset + length > size) {
+	ret = ERANGE;
+	goto cleanup;
+    }
+
+    ret = krb5_data_alloc(data, length);
+    if (ret)
+	goto cleanup;
+
+    if (length) {
+	sp->seek(sp, offset, SEEK_SET);
+
+	size = sp->fetch(sp, data->data, length);
+	heim_assert(size == length, "incomplete buffer fetched");
+    }
+
+cleanup:
+    sp->seek(sp, cur, SEEK_SET);
+
+    return ret;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+_krb5_ret_utf8_from_ucs2le_at_offset(krb5_storage *sp,
+				     size_t offset,
+				     size_t length,
+				     char **utf8)
+{
+    krb5_error_code ret;
+    krb5_data data;
+    size_t ucs2len = length / 2;
+    uint16_t *ucs2 = NULL;
+    size_t u8len;
+    unsigned int flags = WIND_RW_LE;
+
+    *utf8 = NULL;
+
+    krb5_data_zero(&data);
+
+    ret = _krb5_ret_data_at_offset(sp, offset, length, &data);
+    if (ret)
+	goto out;
+
+    ucs2 = malloc(sizeof(ucs2[0]) * ucs2len);
+    if (ucs2 == NULL) {
+	ret = ENOMEM;
+	goto out;
+    }
+
+    ret = wind_ucs2read(data.data, data.length, &flags, ucs2, &ucs2len);
+    if (ret)
+	goto out;
+
+    ret = wind_ucs2utf8_length(ucs2, ucs2len, &u8len);
+    if (ret)
+	goto out;
+
+    u8len += 1; /* Add space for NUL */
+
+    *utf8 = malloc(u8len);
+    if (*utf8 == NULL) {
+	ret = ENOMEM;
+	goto out;
+    }
+
+    ret = wind_ucs2utf8(ucs2, ucs2len, *utf8, &u8len);
+    if (ret)
+	goto out;
+
+out:
+    if (ret && *utf8) {
+	free(*utf8);
+	*utf8 = NULL;
+    }
+    free(ucs2);
+    krb5_data_free(&data);
+
+    return ret;
+}
diff --git a/lib/krb5/test_pac.c b/lib/krb5/test_pac.c
index 133859407..bd1d51c8e 100644
--- a/lib/krb5/test_pac.c
+++ b/lib/krb5/test_pac.c
@@ -735,6 +735,64 @@ static const unsigned char s4u2proxy_rodc[] =
     "\x69\x9d\x4f\x44\xce\xc3\x6d\xae\x51\x20\x24\x61\xb6\x6f\xff\x27"
     "\xc4\x36\xb1";
 
+static const unsigned char extra_logon_info[] =
+    "\x08\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\xf0\x01\x00\x00"
+    "\x88\x00\x00\x00\x00\x00\x00\x00\x0a\x00\x00\x00\x1e\x00\x00\x00"
+    "\x78\x02\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x00\x98\x00\x00\x00"
+    "\x98\x02\x00\x00\x00\x00\x00\x00\x0d\x00\x00\x00\x00\x00\x00\x00"
+    "\x30\x03\x00\x00\x00\x00\x00\x00\x11\x00\x00\x00\x08\x00\x00\x00"
+    "\x30\x03\x00\x00\x00\x00\x00\x00\x12\x00\x00\x00\x1c\x00\x00\x00"
+    "\x38\x03\x00\x00\x00\x00\x00\x00\x06\x00\x00\x00\x10\x00\x00\x00"
+    "\x58\x03\x00\x00\x00\x00\x00\x00\x07\x00\x00\x00\x10\x00\x00\x00"
+    "\x68\x03\x00\x00\x00\x00\x00\x00\x01\x10\x08\x00\xcc\xcc\xcc\xcc"
+    "\xe0\x01\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00"
+    "\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\xff\x7f\xff\xff\xff\xff"
+    "\xff\xff\xff\x7f\x59\xa1\x0f\x59\x77\xf5\xd7\x01\x59\xa1\x0f\x59"
+    "\x77\xf5\xd7\x01\x59\x21\x69\x4e\x78\x16\xd8\x01\x14\x00\x14\x00"
+    "\x04\x00\x02\x00\x00\x00\x00\x00\x08\x00\x02\x00\x00\x00\x00\x00"
+    "\x0c\x00\x02\x00\x00\x00\x00\x00\x10\x00\x02\x00\x00\x00\x00\x00"
+    "\x14\x00\x02\x00\x00\x00\x00\x00\x18\x00\x02\x00\x00\x00\x00\x00"
+    "\x4d\x04\x00\x00\x01\x02\x00\x00\x01\x00\x00\x00\x1c\x00\x02\x00"
+    "\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x00\x00\x00\x00\x0e\x00\x10\x00\x20\x00\x02\x00\x0e\x00\x10\x00"
+    "\x24\x00\x02\x00\x28\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x02\x00\x00\x00\x2c\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x00\x00\x00\x00\x0a\x00\x00\x00\x00\x00\x00\x00\x0a\x00\x00\x00"
+    "\x63\x00\x39\x00\x64\x00\x38\x00\x30\x00\x31\x00\x61\x00\x38\x00"
+    "\x5f\x00\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\x01\x00\x00\x00\x01\x02\x00\x00\x07\x00\x00\x00\x08\x00\x00\x00"
+    "\x00\x00\x00\x00\x07\x00\x00\x00\x54\x00\x45\x00\x53\x00\x54\x00"
+    "\x2d\x00\x44\x00\x43\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00"
+    "\x07\x00\x00\x00\x45\x00\x58\x00\x41\x00\x4d\x00\x50\x00\x4c\x00"
+    "\x45\x00\x00\x00\x04\x00\x00\x00\x01\x04\x00\x00\x00\x00\x00\x05"
+    "\x15\x00\x00\x00\xa1\xa5\x92\x7f\x29\x19\xc5\x3b\xbb\x56\xb0\x05"
+    "\x02\x00\x00\x00\x30\x00\x02\x00\x07\x00\x00\x00\x34\x00\x02\x00"
+    "\x07\x00\x00\x00\x05\x00\x00\x00\x01\x05\x00\x00\x00\x00\x00\x05"
+    "\x15\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    "\xf1\x01\x00\x00\x01\x00\x00\x00\x01\x01\x00\x00\x00\x00\x00\x12"
+    "\x01\x00\x00\x00\x00\x00\x00\x00\x00\xb6\x8f\x5a\x77\xf5\xd7\x01"
+    "\x14\x00\x63\x00\x39\x00\x64\x00\x38\x00\x30\x00\x31\x00\x61\x00"
+    "\x38\x00\x5f\x00\x30\x00\x00\x00\x2c\x00\x18\x00\x16\x00\x48\x00"
+    "\x03\x00\x00\x00\x14\x00\x60\x00\x1c\x00\x78\x00\x00\x00\x00\x00"
+    "\x63\x00\x39\x00\x64\x00\x38\x00\x30\x00\x31\x00\x61\x00\x38\x00"
+    "\x5f\x00\x30\x00\x40\x00\x45\x00\x58\x00\x41\x00\x4d\x00\x50\x00"
+    "\x4c\x00\x45\x00\x2e\x00\x43\x00\x4f\x00\x4d\x00\x00\x00\x00\x00"
+    "\x45\x00\x58\x00\x41\x00\x4d\x00\x50\x00\x4c\x00\x45\x00\x2e\x00"
+    "\x43\x00\x4f\x00\x4d\x00\x00\x00\x63\x00\x39\x00\x64\x00\x38\x00"
+    "\x30\x00\x31\x00\x61\x00\x38\x00\x5f\x00\x30\x00\x00\x00\x00\x00"
+    "\x01\x05\x00\x00\x00\x00\x00\x05\x15\x00\x00\x00\xa1\xa5\x92\x7f"
+    "\x29\x19\xc5\x3b\xbb\x56\xb0\x05\x4d\x04\x00\x00\x00\x00\x00\x00"
+    "\x02\x00\x00\x00\x01\x00\x00\x00\x01\x05\x00\x00\x00\x00\x00\x05"
+    "\x15\x00\x00\x00\xa1\xa5\x92\x7f\x29\x19\xc5\x3b\xbb\x56\xb0\x05"
+    "\x4d\x04\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00\xfd\x39\xd8\x32"
+    "\x3b\x8c\xa5\xfe\x6b\x3d\x27\xff\x10\x00\x00\x00\x2f\x99\x7e\x57"
+    "\xca\xe4\xe1\xc7\x1b\xc0\xbd\xee";
+
 struct test_pac_ticket {
     const char *name;
     const unsigned char *ticket;
@@ -901,7 +959,7 @@ main(int argc, char **argv)
 
     ret = krb5_init_context(&context);
     if (ret)
-	errx(1, "krb5_init_contex");
+	errx(1, "krb5_init_context");
 
     krb5_enctype_enable(context, ETYPE_DES_CBC_MD5);
 
@@ -1018,6 +1076,34 @@ main(int argc, char **argv)
     krb5_pac_free(context, pac);
     krb5_free_principal(context, p2);
 
+    /*
+     * check extra logon info PAC
+     */
+    ret = krb5_pac_parse(context, extra_logon_info,
+			 sizeof(extra_logon_info) - 1, &pac);
+    if (ret)
+	krb5_err(context, 1, ret, "krb5_pac_parse");
+
+    {
+	krb5_principal upn = NULL;
+	uint32_t flags = 0;
+	krb5_principal sam_name = NULL;
+	krb5_data sid;
+
+	krb5_data_zero(&sid);
+
+	ret = _krb5_pac_get_upn_dns_info(context, pac, &upn,
+					 &flags, &sam_name, &sid);
+	if (ret)
+	    krb5_err(context, 1, ret, "_krb5_pac_get_upn_dns_info");
+
+	krb5_free_principal(context, upn);
+	krb5_free_principal(context, sam_name);
+	krb5_data_free(&sid);
+    }
+
+    krb5_pac_free(context, pac);
+
     /*
      * Test empty free
      */
diff --git a/lib/krb5/version-script.map b/lib/krb5/version-script.map
index 2cc49fe0f..0245dffba 100644
--- a/lib/krb5/version-script.map
+++ b/lib/krb5/version-script.map
@@ -814,6 +814,7 @@ HEIMDAL_KRB5_2.0 {
 		_krb5_get_int;
 		_krb5_get_int64;
 		_krb5_pac_sign;
+		_krb5_pac_get_canon_principal;
 		_krb5_kdc_pac_sign_ticket;
 		_krb5_kdc_pac_ticket_parse;
 		_kdc_tkt_insert_pac;
diff --git a/tests/gss/check-context.in b/tests/gss/check-context.in
index 699e373e6..42ea15eec 100644
--- a/tests/gss/check-context.in
+++ b/tests/gss/check-context.in
@@ -100,6 +100,7 @@ ${ktutil} -k ${keytab} rename --no-delete host/short@${R} host/long.test.h5l.se@
 ${kadmin} add -p kaka --use-defaults digest/${R}@${R} || exit 1
 
 ${kadmin} add -p u1 --use-defaults user1@${R} || exit 1
+${kadmin} mod --alias=user1.alias user1@${R} || exit 1
 
 # Create a server principal with no AES
 ${kadmin} add -p p1 --use-defaults host/no-aes.test.h5l.se@${R} || exit 1
@@ -312,6 +313,22 @@ done
 
 rm ${keytabfile}.new
 
+echo "====== test PAC-based name canonicalization"
+
+${kdestroy}
+${kinit} --password-file=${objdir}/foopassword user1.alias@${R} || \
+	{ eval "$testfailed"; }
+
+for mech in krb5 spnego; do
+	KRB5_CONFIG="${objdir}/new_clients_k5.conf" ${context} -v \
+		--mech-type=$mech host@lucid.test.h5l.se > name-canon.log || \
+		{ eval "$testfailed"; }
+	grep "client name:" name-canon.log | grep "user1.alias@TEST.H5L.SE" > /dev/null && \
+		{ echo "client name not canonicalized"; eval "$testfailed"; }
+	grep "client name:" name-canon.log | grep "user1@TEST.H5L.SE" > /dev/null || \
+		{ echo "wrong client name"; eval "$testfailed"; }
+done
+
 echo "====== test channel-bindings."
 
 for mech in krb5 spnego; do
diff --git a/tests/gss/new_clients_k5.conf.in b/tests/gss/new_clients_k5.conf.in
index 145f8dc46..41c9e21d5 100644
--- a/tests/gss/new_clients_k5.conf.in
+++ b/tests/gss/new_clients_k5.conf.in
@@ -2,3 +2,4 @@ include @objdirabs@/krb5.conf
 
 [libdefaults]
 	client_aware_channel_bindings = true
+	report_canonical_client_name = true