From: David Howells Subject: [PATCH 06/16] KEYS: Asymmetric public-key algorithm crypto key subtype Date: Fri, 14 Sep 2012 00:48:57 +0100 Message-ID: <20120913234857.3575.38851.stgit@warthog.procyon.org.uk> References: <20120913234802.3575.77103.stgit@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: linux-crypto@vger.kernel.org, zohar@us.ibm.com, dmitry.kasatkin@intel.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org To: herbert@gondor.hengli.com.au, rusty@rustcorp.com.au Return-path: In-Reply-To: <20120913234802.3575.77103.stgit@warthog.procyon.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org Add a subtype for supporting asymmetric public-key encryption algorithms such as DSA (FIPS-186) and RSA (PKCS#1 / RFC1337). Signed-off-by: David Howells --- crypto/asymmetric_keys/Kconfig | 8 +++ crypto/asymmetric_keys/Makefile | 2 + crypto/asymmetric_keys/public_key.c | 108 +++++++++++++++++++++++++++++++++++ crypto/asymmetric_keys/public_key.h | 28 +++++++++ include/crypto/public_key.h | 109 +++++++++++++++++++++++++++++++++++ 5 files changed, 255 insertions(+) create mode 100644 crypto/asymmetric_keys/public_key.c create mode 100644 crypto/asymmetric_keys/public_key.h create mode 100644 include/crypto/public_key.h diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig index cad29b3..bbfccaa 100644 --- a/crypto/asymmetric_keys/Kconfig +++ b/crypto/asymmetric_keys/Kconfig @@ -9,5 +9,13 @@ menuconfig ASYMMETRIC_KEY_TYPE if ASYMMETRIC_KEY_TYPE +config ASYMMETRIC_PUBLIC_KEY_SUBTYPE + tristate "Asymmetric public-key crypto algorithm subtype" + select MPILIB + help + This option provides support for asymmetric public key type handling. + If signature generation and/or verification are to be used, + appropriate hash algorithms (such as SHA-1) must be available. + ENOPKG will be reported if the requisite algorithm is unavailable. endif # ASYMMETRIC_KEY_TYPE diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile index b725bcc..5ed46ee 100644 --- a/crypto/asymmetric_keys/Makefile +++ b/crypto/asymmetric_keys/Makefile @@ -5,3 +5,5 @@ obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o asymmetric_keys-y := asymmetric_type.o + +obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c new file mode 100644 index 0000000..cb2e291 --- /dev/null +++ b/crypto/asymmetric_keys/public_key.c @@ -0,0 +1,108 @@ +/* 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 +#include +#include +#include +#include +#include +#include "public_key.h" + +MODULE_LICENSE("GPL"); + +const char *const pkey_algo[PKEY_ALGO__LAST] = { + [PKEY_ALGO_DSA] = "DSA", + [PKEY_ALGO_RSA] = "RSA", +}; +EXPORT_SYMBOL_GPL(pkey_algo); + +const char *const pkey_hash_algo[PKEY_HASH__LAST] = { + [PKEY_HASH_MD4] = "md4", + [PKEY_HASH_MD5] = "md5", + [PKEY_HASH_SHA1] = "sha1", + [PKEY_HASH_RIPE_MD_160] = "rmd160", + [PKEY_HASH_SHA256] = "sha256", + [PKEY_HASH_SHA384] = "sha384", + [PKEY_HASH_SHA512] = "sha512", + [PKEY_HASH_SHA224] = "sha224", +}; +EXPORT_SYMBOL_GPL(pkey_hash_algo); + +const char *const pkey_id_type[PKEY_ID_TYPE__LAST] = { + [PKEY_ID_PGP] = "PGP", + [PKEY_ID_X509] = "X509", +}; +EXPORT_SYMBOL_GPL(pkey_id_type); + +/* + * 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[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. + */ +static int public_key_verify_signature(const struct key *key, + const struct public_key_signature *sig) +{ + const struct public_key *pk = key->payload.data; + + if (!pk->algo->verify_signature) + return -ENOTSUPP; + + if (sig->nr_mpi != pk->algo->n_sig_mpi) { + pr_debug("Signature has %u MPI not %u\n", + sig->nr_mpi, pk->algo->n_sig_mpi); + return -EINVAL; + } + + return pk->algo->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, +}; +EXPORT_SYMBOL_GPL(public_key_subtype); diff --git a/crypto/asymmetric_keys/public_key.h b/crypto/asymmetric_keys/public_key.h new file mode 100644 index 0000000..1f86aad --- /dev/null +++ b/crypto/asymmetric_keys/public_key.h @@ -0,0 +1,28 @@ +/* Public key algorithm internals + * + * 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. + */ + +#include + +extern struct asymmetric_key_subtype public_key_subtype; + +/* + * Public key algorithm definition. + */ +struct public_key_algorithm { + const char *name; + u8 n_pub_mpi; /* Number of MPIs in public key */ + u8 n_sec_mpi; /* Number of MPIs in secret key */ + u8 n_sig_mpi; /* Number of MPIs in a signature */ + int (*verify_signature)(const struct public_key *key, + const struct public_key_signature *sig); +}; diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h new file mode 100644 index 0000000..65d9879 --- /dev/null +++ b/include/crypto/public_key.h @@ -0,0 +1,109 @@ +/* Asymmetric public-key algorithm definitions + * + * 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. + */ + +#ifndef _LINUX_PUBLIC_KEY_H +#define _LINUX_PUBLIC_KEY_H + +#include + +enum pkey_algo { + PKEY_ALGO_DSA, + PKEY_ALGO_RSA, + PKEY_ALGO__LAST +}; + +extern const char *const pkey_algo[PKEY_ALGO__LAST]; + +enum pkey_hash_algo { + PKEY_HASH_MD4, + PKEY_HASH_MD5, + PKEY_HASH_SHA1, + PKEY_HASH_RIPE_MD_160, + PKEY_HASH_SHA256, + PKEY_HASH_SHA384, + PKEY_HASH_SHA512, + PKEY_HASH_SHA224, + PKEY_HASH__LAST +}; + +extern const char *const pkey_hash_algo[PKEY_HASH__LAST]; + +enum pkey_id_type { + PKEY_ID_PGP, /* OpenPGP generated key ID */ + PKEY_ID_X509, /* X.509 arbitrary subjectKeyIdentifier */ + PKEY_ID_TYPE__LAST +}; + +extern const char *const pkey_id_type[PKEY_ID_TYPE__LAST]; + +/* + * Cryptographic data for the public-key subtype of the asymmetric key type. + * + * Note that this may include private part of the key as well as the public + * part. + */ +struct public_key { + const struct public_key_algorithm *algo; + u8 capabilities; +#define PKEY_CAN_ENCRYPT 0x01 +#define PKEY_CAN_DECRYPT 0x02 +#define PKEY_CAN_ENCDEC (PKEY_CAN_ENCRYPT | PKEY_CAN_DECRYPT) +#define PKEY_CAN_SIGN 0x04 +#define PKEY_CAN_VERIFY 0x08 +#define PKEY_CAN_SIGVER (PKEY_CAN_SIGN | PKEY_CAN_VERIFY) + enum pkey_id_type id_type : 8; + union { + MPI mpi[5]; + struct { + MPI p; /* DSA prime */ + MPI q; /* DSA group order */ + MPI g; /* DSA group generator */ + MPI y; /* DSA public-key value = g^x mod p */ + MPI x; /* DSA secret exponent (if present) */ + } dsa; + struct { + MPI n; /* RSA public modulus */ + MPI e; /* RSA public encryption exponent */ + MPI d; /* RSA secret encryption exponent (if present) */ + MPI p; /* RSA secret prime (if present) */ + MPI q; /* RSA secret prime (if present) */ + } rsa; + }; + + u8 key_id[8]; /* ID of this key pair */ + u8 key_id_size; /* Number of bytes in key_id */ +}; + +extern void public_key_destroy(void *payload); + +/* + * Public key cryptography signature data + */ +struct public_key_signature { + u8 *digest; + u8 digest_size; /* Number of bytes in digest */ + u8 nr_mpi; /* Occupancy of mpi[] */ + enum pkey_hash_algo pkey_hash_algo : 8; + union { + MPI mpi[2]; + struct { + MPI s; /* m^d mod n */ + } rsa; + struct { + MPI r; + MPI s; + } dsa; + }; +}; + +#endif /* _LINUX_PUBLIC_KEY_H */