EVP_SIGNATURE-LMS(7ossl) OpenSSL EVP_SIGNATURE-LMS(7ossl)
NAME
EVP_SIGNATURE-LMS - The EVP_PKEY Leighton-Micali Signature (LMS)
implementation
DESCRIPTION
The LMS EVP_PKEY implementation supports Leighton-Micali Signatures
(LMS) described in [RFC
8554](https://datatracker.ietf.org/doc/html/rfc8854) and [SP
800-208](https://csrc.nist.gov/pubs/sp/800/208/final). The OpenSSL
providers only support LMS signature verification, as this is a [SP
800-208](https://csrc.nist.gov/pubs/sp/800/208/final) requirement for
FIPS software modules.
EVP_PKEY_verify_message_init() and EVP_PKEY_verify() are the only
supported functions used for LMS signatures. Streaming is not currently
supported, and since the signature data contains data related to the
digest used, functions that specify the digest name are not necessary.
NOTES
LMS support is disabled by default at compile-time. To enable, specify
the enable-lms build configuration option.
LMS should only be used for older deployments. New deployments should
use either EVP_SIGNATURE-ML-DSA(7) or <L/EVP_SIGNATURE-SLH-DSA(7)>.
EXAMPLES
Error checking has been omitted from the following examples
LMS signature verification
/* See L<EVP_PKEY-LMS(7)/EXAMPLES for an example of loading a LMS |pub| key */
ctx = EVP_PKEY_CTX_new_from_pkey(libctx, pub, propq);
sig = EVP_SIGNATURE_fetch(libctx, "LMS", propq);
EVP_PKEY_verify_message_init(ctx, sig, NULL);
/*
* EVP_PKEY_verify_message_update() and EVP_PKEY_verify_message_final()
* are not supported
*/
ret = EVP_PKEY_verify(ctx, sigdata, sigdata_len, msg, msglen);
/*
* ret == 1 indicates success, 0 verify failure and < 0 for some
* other error.
*/
SEE ALSO
EVP_PKEY-LMS(7), provider-signature(7),
HISTORY
This functionality was added in OpenSSL 3.6.
COPYRIGHT
Copyright 2025 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.6.0 2025-10-01 EVP_SIGNATURE-LMS(7ossl)
openssl 3.6.0 - Generated Wed Jan 28 19:18:16 CST 2026