1 /* In-software asymmetric public-key crypto subtype 2 * 3 * See Documentation/crypto/asymmetric-keys.txt 4 * 5 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. 6 * Written by David Howells (dhowells@redhat.com) 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public Licence 10 * as published by the Free Software Foundation; either version 11 * 2 of the Licence, or (at your option) any later version. 12 */ 13 14 #define pr_fmt(fmt) "PKEY: "fmt 15 #include <linux/module.h> 16 #include <linux/export.h> 17 #include <linux/kernel.h> 18 #include <linux/slab.h> 19 #include <linux/seq_file.h> 20 #include <keys/asymmetric-subtype.h> 21 #include "public_key.h" 22 23 MODULE_LICENSE("GPL"); 24 25 const char *const pkey_algo[PKEY_ALGO__LAST] = { 26 [PKEY_ALGO_DSA] = "DSA", 27 [PKEY_ALGO_RSA] = "RSA", 28 }; 29 EXPORT_SYMBOL_GPL(pkey_algo); 30 31 const char *const pkey_hash_algo[PKEY_HASH__LAST] = { 32 [PKEY_HASH_MD4] = "md4", 33 [PKEY_HASH_MD5] = "md5", 34 [PKEY_HASH_SHA1] = "sha1", 35 [PKEY_HASH_RIPE_MD_160] = "rmd160", 36 [PKEY_HASH_SHA256] = "sha256", 37 [PKEY_HASH_SHA384] = "sha384", 38 [PKEY_HASH_SHA512] = "sha512", 39 [PKEY_HASH_SHA224] = "sha224", 40 }; 41 EXPORT_SYMBOL_GPL(pkey_hash_algo); 42 43 const char *const pkey_id_type[PKEY_ID_TYPE__LAST] = { 44 [PKEY_ID_PGP] = "PGP", 45 [PKEY_ID_X509] = "X509", 46 }; 47 EXPORT_SYMBOL_GPL(pkey_id_type); 48 49 /* 50 * Provide a part of a description of the key for /proc/keys. 51 */ 52 static void public_key_describe(const struct key *asymmetric_key, 53 struct seq_file *m) 54 { 55 struct public_key *key = asymmetric_key->payload.data; 56 57 if (key) 58 seq_printf(m, "%s.%s", 59 pkey_id_type[key->id_type], key->algo->name); 60 } 61 62 /* 63 * Destroy a public key algorithm key. 64 */ 65 void public_key_destroy(void *payload) 66 { 67 struct public_key *key = payload; 68 int i; 69 70 if (key) { 71 for (i = 0; i < ARRAY_SIZE(key->mpi); i++) 72 mpi_free(key->mpi[i]); 73 kfree(key); 74 } 75 } 76 EXPORT_SYMBOL_GPL(public_key_destroy); 77 78 /* 79 * Verify a signature using a public key. 80 */ 81 static int public_key_verify_signature(const struct key *key, 82 const struct public_key_signature *sig) 83 { 84 const struct public_key *pk = key->payload.data; 85 86 if (!pk->algo->verify_signature) 87 return -ENOTSUPP; 88 89 if (sig->nr_mpi != pk->algo->n_sig_mpi) { 90 pr_debug("Signature has %u MPI not %u\n", 91 sig->nr_mpi, pk->algo->n_sig_mpi); 92 return -EINVAL; 93 } 94 95 return pk->algo->verify_signature(pk, sig); 96 } 97 98 /* 99 * Public key algorithm asymmetric key subtype 100 */ 101 struct asymmetric_key_subtype public_key_subtype = { 102 .owner = THIS_MODULE, 103 .name = "public_key", 104 .describe = public_key_describe, 105 .destroy = public_key_destroy, 106 .verify_signature = public_key_verify_signature, 107 }; 108 EXPORT_SYMBOL_GPL(public_key_subtype); 109