KeyValue has been disabled in libxmlsec >= 1.3.3, as it can be a security
liability in other settings than SAML:
(xmlsec-core) Disabled KeyValue and DEREncodedKeyValue XML nodes by default. Use the '--enabled-key-data' option for the xmlsec command line utility or update the 'keyInfoCtx->enabledKeyData' parameter if you need to re-enable these nodes (also see question 3.5 in the FAQ).
For compatibility with libxmlsec1>=1.3.0, as we do not use KeyName to
reference the wrapping key:
(API breaking change) Changed the key search to strict mode: only keys referenced by KeyInfo are used. To restore the old "lax" mode, set XMLSEC_KEYINFO_FLAGS_LAX_KEY_SEARCH flag on xmlSecKeyInfoCtx or use '--lax-key-search' option for XMLSec command line utility.
xmlSecCryptoAppKeyLoad was removed from libxmlsec1 in version >= 1.3.3:
(xmlsec-core) Removed previously deprecated functions, defines, etc.
xmlSecCryptoAppKeyLoadEx was introduced in libxmlsec in version 1.3.0.
Benjamin Dauvergne