ldap: detect version of "legacy" LDAP
Legacy LDAP means an OpenLDAP-compatible implementation
without the private API `ldap_init_fd()` introduced in OpenLDAP
2.4.6+ (2007-10-31), and not WinLDAP.
One known example is Apple's LDAP build, which is based on
OpenLDAP 2.4.28 (2011-11-25), without providing this private API.
The version query API was introduced around 1998-1999, before
the minimum (2.0 2000-08-01) required by curl.
Follow-up to 3e2a946926853608d67805bd9f4a58345fff364a #19808
Closes #19832
diff --git a/lib/ldap.c b/lib/ldap.c
index 6104ff2..92cfa39 100644
--- a/lib/ldap.c
+++ b/lib/ldap.c
@@ -1029,7 +1029,27 @@
#ifdef USE_WIN32_LDAP
curl_msnprintf(buf, bufsz, "WinLDAP");
#else
- curl_msnprintf(buf, bufsz, "LDAP/1");
+#ifdef __APPLE__
+ static const char *flavor = "/Apple";
+#else
+ static const char *flavor = "";
+#endif
+ LDAPAPIInfo api;
+ api.ldapai_info_version = LDAP_API_INFO_VERSION;
+
+ if(ldap_get_option(NULL, LDAP_OPT_API_INFO, &api) == LDAP_OPT_SUCCESS) {
+ unsigned int patch = (unsigned int)(api.ldapai_vendor_version % 100);
+ unsigned int major = (unsigned int)(api.ldapai_vendor_version / 10000);
+ unsigned int minor =
+ (((unsigned int)api.ldapai_vendor_version - major * 10000)
+ - patch) / 100;
+ curl_msnprintf(buf, bufsz, "%s/%u.%u.%u%s",
+ api.ldapai_vendor_name, major, minor, patch, flavor);
+ ldap_memfree(api.ldapai_vendor_name);
+ ber_memvfree((void **)api.ldapai_extensions);
+ }
+ else
+ curl_msnprintf(buf, bufsz, "LDAP/1");
#endif
}