slapi-nis: normalize memberUid search filter when searching AD users

memberUid attribute uses IA5 String comparison which is case-sensitive.
At the same time, uid attribute uses case-insensitive comparison.

When memberUid is constructed for groups from AD, SSSD normalizes names
to a lower case. slapi-nis records these entries as they produced by SSSD.
However, the search filter is not modified, thus case-sensitive comparison
of memberUid attribute may fail match of the original term.

Workaround the issue by low-casing memberUid term in the search filter
if it includes '@' sign, meaning we are searching on fully-qualified user
name provided by SSSD.

https://bugzilla.redhat.com/show_bug.cgi?id=1130131

1 files changed, 32 insertions, 3 deletions

diff --git a/src/back-sch-nss.c b/src/back-sch-nss.c
index 26d4b8c..12ae589 100644
--- a/src/back-sch-nss.c
+++ b/src/back-sch-nss.c
@@ -60,7 +60,7 @@ bvstrprefix(const struct berval *bval, const char *s)
 
 	len = strlen(s);
 	if (len < bval->bv_len) {
-		return strncasecmp(bval->bv_val, s, len) != 0;
+		return slapi_utf8ncasecmp((unsigned char *) bval->bv_val, (unsigned char *) s, len) != 0;
 	}
 
 	return 1;
@@ -75,9 +75,9 @@ bvstrcasecmp(const struct berval *bval, const char *s)
 
 	len = strlen(s);
 	if (len == bval->bv_len) {
-		return strncasecmp(bval->bv_val, s, len);
+		return slapi_utf8ncasecmp((unsigned char *) bval->bv_val, (unsigned char *) s, len);
 	}
-	c = strncasecmp(bval->bv_val, s, MIN(bval->bv_len, len));
+	c = slapi_utf8ncasecmp((unsigned char *) bval->bv_val, (unsigned char *) s, MIN(bval->bv_len, len));
 	if (c != 0) {
 		return c;
 	}
@@ -111,6 +111,35 @@ backend_search_filter_has_cn_uid(Slapi_Filter *filter, void *arg)
 		} else if (0 == strcasecmp(filter_type, "cn")) {
 			config->name_set = TRUE;
 		} else if (0 == strcasecmp(filter_type, "memberUid")) {
+			/* memberUid is case-sensitive in RFC 2307 but uid is case-insensitive
+			 * When memberUid is generated for SSSD-provided entries, it is low-cased,
+			 * we need to low case the filter value to actually match it.
+			 * However, we will do it only for fully qualified names as they are coming from SSSD. */
+			char *memberUid = NULL;
+			char *lwMemberUid = NULL;
+			unsigned int i = 0;
+
+			for (i=0; i < bval->bv_len ; i++) {
+				if (bval->bv_val[i] == '@')
+					break;
+			}
+
+			if (i < bval->bv_len) {
+				memberUid = slapi_ch_malloc(bval->bv_len + 1);
+				if (memberUid != NULL) {
+					memcpy(memberUid, bval->bv_val, bval->bv_len);
+					memberUid[bval->bv_len] = '\0';
+					lwMemberUid = (char *) slapi_utf8StrToLower((unsigned char*) memberUid);
+					if (lwMemberUid != NULL) {
+						struct berval bval_lw = {0, NULL};
+						bval_lw.bv_len = strlen((const char *) lwMemberUid);
+						bval_lw.bv_val = lwMemberUid;
+						slapi_ber_bvdone(bval);
+						slapi_ber_bvcpy(bval, &bval_lw);
+					}
+					slapi_ch_free_string(&memberUid);
+				}
+			}
 			config->name_set = TRUE;
 			config->search_members = TRUE;
 		} else if ((0 == strcasecmp(filter_type, "objectClass")) &&