/* In-software asymmetric public-key crypto subtype * * See Documentation/crypto/asymmetric-keys.txt * * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #define pr_fmt(fmt) "PKEY: "fmt #include <linux/module.h> #include <linux/export.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/seq_file.h> #include <keys/asymmetric-subtype.h> #include "public_key.h" MODULE_LICENSE("GPL"); const char *const pkey_algo_name[PKEY_ALGO__LAST] = { [PKEY_ALGO_DSA] = "DSA", [PKEY_ALGO_RSA] = "RSA", }; EXPORT_SYMBOL_GPL(pkey_algo_name); const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = { #if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \ defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE) [PKEY_ALGO_RSA] = &RSA_public_key_algorithm, #endif }; EXPORT_SYMBOL_GPL(pkey_algo); const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = { [PKEY_ID_PGP] = "PGP", [PKEY_ID_X509] = "X509", }; EXPORT_SYMBOL_GPL(pkey_id_type_name); /* * Provide a part of a description of the key for /proc/keys. */ static void public_key_describe(const struct key *asymmetric_key, struct seq_file *m) { struct public_key *key = asymmetric_key->payload.data; if (key) seq_printf(m, "%s.%s", pkey_id_type_name[key->id_type], key->algo->name); } /* * Destroy a public key algorithm key. */ void public_key_destroy(void *payload) { struct public_key *key = payload; int i; if (key) { for (i = 0; i < ARRAY_SIZE(key->mpi); i++) mpi_free(key->mpi[i]); kfree(key); } } EXPORT_SYMBOL_GPL(public_key_destroy); /* * Verify a signature using a public key. */ int public_key_verify_signature(const struct public_key *pk, const struct public_key_signature *sig) { const struct public_key_algorithm *algo; BUG_ON(!pk); BUG_ON(!pk->mpi[0]); BUG_ON(!pk->mpi[1]); BUG_ON(!sig); BUG_ON(!sig->digest); BUG_ON(!sig->mpi[0]); algo = pk->algo; if (!algo) { if (pk->pkey_algo >= PKEY_ALGO__LAST) return -ENOPKG; algo = pkey_algo[pk->pkey_algo]; if (!algo) return -ENOPKG; } if (!algo->verify_signature) return -ENOTSUPP; if (sig->nr_mpi != algo->n_sig_mpi) { pr_debug("Signature has %u MPI not %u\n", sig->nr_mpi, algo->n_sig_mpi); return -EINVAL; } return algo->verify_signature(pk, sig); } EXPORT_SYMBOL_GPL(public_key_verify_signature); static int public_key_verify_signature_2(const struct key *key, const struct public_key_signature *sig) { const struct public_key *pk = key->payload.data; return public_key_verify_signature(pk, sig); } /* * Public key algorithm asymmetric key subtype */ struct asymmetric_key_subtype public_key_subtype = { .owner = THIS_MODULE, .name = "public_key", .describe = public_key_describe, .destroy = public_key_destroy, .verify_signature = public_key_verify_signature_2, }; EXPORT_SYMBOL_GPL(public_key_subtype);