diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/Kconfig | 1 | ||||
| -rw-r--r-- | crypto/Makefile | 1 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/.gitignore | 1 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/Kconfig | 38 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/Makefile | 27 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/asymmetric_keys.h | 15 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/asymmetric_type.c | 274 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/public_key.c | 108 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/public_key.h | 30 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/rsa.c | 277 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/signature.c | 49 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/x509.asn1 | 60 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/x509_cert_parser.c | 496 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/x509_parser.h | 36 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/x509_public_key.c | 239 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/x509_rsakey.asn1 | 4 |
16 files changed, 1656 insertions, 0 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig index 50402dc0ea3..6563366bae8 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -1216,5 +1216,6 @@ config CRYPTO_USER_API_SKCIPHER key cipher algorithms. source "drivers/crypto/Kconfig" +source crypto/asymmetric_keys/Kconfig endif # if CRYPTO diff --git a/crypto/Makefile b/crypto/Makefile index a301ad2b258..8cf61ffe351 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -97,3 +97,4 @@ obj-$(CONFIG_CRYPTO_USER_API_SKCIPHER) += algif_skcipher.o # obj-$(CONFIG_XOR_BLOCKS) += xor.o obj-$(CONFIG_ASYNC_CORE) += async_tx/ +obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys/ diff --git a/crypto/asymmetric_keys/.gitignore b/crypto/asymmetric_keys/.gitignore new file mode 100644 index 00000000000..ee328374dba --- /dev/null +++ b/crypto/asymmetric_keys/.gitignore @@ -0,0 +1 @@ +*-asn1.[ch] diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig new file mode 100644 index 00000000000..6d2c2ea1255 --- /dev/null +++ b/crypto/asymmetric_keys/Kconfig @@ -0,0 +1,38 @@ +menuconfig ASYMMETRIC_KEY_TYPE + tristate "Asymmetric (public-key cryptographic) key type" + depends on KEYS + help + This option provides support for a key type that holds the data for + the asymmetric keys used for public key cryptographic operations such + as encryption, decryption, signature generation and signature + verification. + +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. + +config PUBLIC_KEY_ALGO_RSA + tristate "RSA public-key algorithm" + depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE + select MPILIB_EXTRA + help + This option enables support for the RSA algorithm (PKCS#1, RFC3447). + +config X509_CERTIFICATE_PARSER + tristate "X.509 certificate parser" + depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE + select ASN1 + select OID_REGISTRY + help + This option procides support for parsing X.509 format blobs for key + data and provides the ability to instantiate a crypto key from a + public key packet found inside the certificate. + +endif # ASYMMETRIC_KEY_TYPE diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile new file mode 100644 index 00000000000..0727204aab6 --- /dev/null +++ b/crypto/asymmetric_keys/Makefile @@ -0,0 +1,27 @@ +# +# Makefile for asymmetric cryptographic keys +# + +obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o + +asymmetric_keys-y := asymmetric_type.o signature.o + +obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o +obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa.o + +# +# X.509 Certificate handling +# +obj-$(CONFIG_X509_CERTIFICATE_PARSER) += x509_key_parser.o +x509_key_parser-y := \ + x509-asn1.o \ + x509_rsakey-asn1.o \ + x509_cert_parser.o \ + x509_public_key.o + +$(obj)/x509_cert_parser.o: $(obj)/x509-asn1.h $(obj)/x509_rsakey-asn1.h +$(obj)/x509-asn1.o: $(obj)/x509-asn1.c $(obj)/x509-asn1.h +$(obj)/x509_rsakey-asn1.o: $(obj)/x509_rsakey-asn1.c $(obj)/x509_rsakey-asn1.h + +clean-files += x509-asn1.c x509-asn1.h +clean-files += x509_rsakey-asn1.c x509_rsakey-asn1.h diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h new file mode 100644 index 00000000000..515b6343081 --- /dev/null +++ b/crypto/asymmetric_keys/asymmetric_keys.h @@ -0,0 +1,15 @@ +/* Internal definitions for asymmetric key type + * + * 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. + */ + +static inline const char *asymmetric_key_id(const struct key *key) +{ + return key->type_data.p[1]; +} diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c new file mode 100644 index 00000000000..cf807654d22 --- /dev/null +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -0,0 +1,274 @@ +/* Asymmetric public-key cryptography key type + * + * See Documentation/security/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 <keys/asymmetric-subtype.h> +#include <keys/asymmetric-parser.h> +#include <linux/seq_file.h> +#include <linux/module.h> +#include <linux/slab.h> +#include "asymmetric_keys.h" + +MODULE_LICENSE("GPL"); + +static LIST_HEAD(asymmetric_key_parsers); +static DECLARE_RWSEM(asymmetric_key_parsers_sem); + +/* + * Match asymmetric keys on (part of) their name + * We have some shorthand methods for matching keys. We allow: + * + * "<desc>" - request a key by description + * "id:<id>" - request a key matching the ID + * "<subtype>:<id>" - request a key of a subtype + */ +static int asymmetric_key_match(const struct key *key, const void *description) +{ + const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key); + const char *spec = description; + const char *id, *kid; + ptrdiff_t speclen; + size_t idlen, kidlen; + + if (!subtype || !spec || !*spec) + return 0; + + /* See if the full key description matches as is */ + if (key->description && strcmp(key->description, description) == 0) + return 1; + + /* All tests from here on break the criterion description into a + * specifier, a colon and then an identifier. + */ + id = strchr(spec, ':'); + if (!id) + return 0; + + speclen = id - spec; + id++; + + /* Anything after here requires a partial match on the ID string */ + kid = asymmetric_key_id(key); + if (!kid) + return 0; + + idlen = strlen(id); + kidlen = strlen(kid); + if (idlen > kidlen) + return 0; + + kid += kidlen - idlen; + if (strcasecmp(id, kid) != 0) + return 0; + + if (speclen == 2 && + memcmp(spec, "id", 2) == 0) + return 1; + + if (speclen == subtype->name_len && + memcmp(spec, subtype->name, speclen) == 0) + return 1; + + return 0; +} + +/* + * Describe the asymmetric key + */ +static void asymmetric_key_describe(const struct key *key, struct seq_file *m) +{ + const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key); + const char *kid = asymmetric_key_id(key); + size_t n; + + seq_puts(m, key->description); + + if (subtype) { + seq_puts(m, ": "); + subtype->describe(key, m); + + if (kid) { + seq_putc(m, ' '); + n = strlen(kid); + if (n <= 8) + seq_puts(m, kid); + else + seq_puts(m, kid + n - 8); + } + + seq_puts(m, " ["); + /* put something here to indicate the key's capabilities */ + seq_putc(m, ']'); + } +} + +/* + * Preparse a asymmetric payload to get format the contents appropriately for the + * internal payload to cut down on the number of scans of the data performed. + * + * We also generate a proposed description from the contents of the key that + * can be used to name the key if the user doesn't want to provide one. + */ +static int asymmetric_key_preparse(struct key_preparsed_payload *prep) +{ + struct asymmetric_key_parser *parser; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (prep->datalen == 0) + return -EINVAL; + + down_read(&asymmetric_key_parsers_sem); + + ret = -EBADMSG; + list_for_each_entry(parser, &asymmetric_key_parsers, link) { + pr_debug("Trying parser '%s'\n", parser->name); + + ret = parser->parse(prep); + if (ret != -EBADMSG) { + pr_debug("Parser recognised the format (ret %d)\n", + ret); + break; + } + } + + up_read(&asymmetric_key_parsers_sem); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* + * Clean up the preparse data + */ +static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep) +{ + struct asymmetric_key_subtype *subtype = prep->type_data[0]; + + pr_devel("==>%s()\n", __func__); + + if (subtype) { + subtype->destroy(prep->payload); + module_put(subtype->owner); + } + kfree(prep->type_data[1]); + kfree(prep->description); +} + +/* + * Instantiate a asymmetric_key defined key. The key was preparsed, so we just + * have to transfer the data here. + */ +static int asymmetric_key_instantiate(struct key *key, struct key_preparsed_payload *prep) +{ + int ret; + + pr_devel("==>%s()\n", __func__); + + ret = key_payload_reserve(key, prep->quotalen); + if (ret == 0) { + key->type_data.p[0] = prep->type_data[0]; + key->type_data.p[1] = prep->type_data[1]; + key->payload.data = prep->payload; + prep->type_data[0] = NULL; + prep->type_data[1] = NULL; + prep->payload = NULL; + } + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* + * dispose of the data dangling from the corpse of a asymmetric key + */ +static void asymmetric_key_destroy(struct key *key) +{ + struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key); + if (subtype) { + subtype->destroy(key->payload.data); + module_put(subtype->owner); + key->type_data.p[0] = NULL; + } + kfree(key->type_data.p[1]); + key->type_data.p[1] = NULL; +} + +struct key_type key_type_asymmetric = { + .name = "asymmetric", + .preparse = asymmetric_key_preparse, + .free_preparse = asymmetric_key_free_preparse, + .instantiate = asymmetric_key_instantiate, + .match = asymmetric_key_match, + .destroy = asymmetric_key_destroy, + .describe = asymmetric_key_describe, +}; +EXPORT_SYMBOL_GPL(key_type_asymmetric); + +/** + * register_asymmetric_key_parser - Register a asymmetric key blob parser + * @parser: The parser to register + */ +int register_asymmetric_key_parser(struct asymmetric_key_parser *parser) +{ + struct asymmetric_key_parser *cursor; + int ret; + + down_write(&asymmetric_key_parsers_sem); + + list_for_each_entry(cursor, &asymmetric_key_parsers, link) { + if (strcmp(cursor->name, parser->name) == 0) { + pr_err("Asymmetric key parser '%s' already registered\n", + parser->name); + ret = -EEXIST; + goto out; + } + } + + list_add_tail(&parser->link, &asymmetric_key_parsers); + + pr_notice("Asymmetric key parser '%s' registered\n", parser->name); + ret = 0; + +out: + up_write(&asymmetric_key_parsers_sem); + return ret; +} +EXPORT_SYMBOL_GPL(register_asymmetric_key_parser); + +/** + * unregister_asymmetric_key_parser - Unregister a asymmetric key blob parser + * @parser: The parser to unregister + */ +void unregister_asymmetric_key_parser(struct asymmetric_key_parser *parser) +{ + down_write(&asymmetric_key_parsers_sem); + list_del(&parser->link); + up_write(&asymmetric_key_parsers_sem); + + pr_notice("Asymmetric key parser '%s' unregistered\n", parser->name); +} +EXPORT_SYMBOL_GPL(unregister_asymmetric_key_parser); + +/* + * Module stuff + */ +static int __init asymmetric_key_init(void) +{ + return register_key_type(&key_type_asymmetric); +} + +static void __exit asymmetric_key_cleanup(void) +{ + unregister_key_type(&key_type_asymmetric); +} + +module_init(asymmetric_key_init); +module_exit(asymmetric_key_cleanup); diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c new file mode 100644 index 00000000000..cb2e29180a8 --- /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 <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[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 00000000000..5e5e3562689 --- /dev/null +++ b/crypto/asymmetric_keys/public_key.h @@ -0,0 +1,30 @@ +/* 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 <crypto/public_key.h> + +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); +}; + +extern const struct public_key_algorithm RSA_public_key_algorithm; diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c new file mode 100644 index 00000000000..4a6a0696f8a --- /dev/null +++ b/crypto/asymmetric_keys/rsa.c @@ -0,0 +1,277 @@ +/* RSA asymmetric public-key algorithm [RFC3447] + * + * 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) "RSA: "fmt +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include "public_key.h" + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("RSA Public Key Algorithm"); + +#define kenter(FMT, ...) \ + pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__) +#define kleave(FMT, ...) \ + pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__) + +/* + * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2]. + */ +static const u8 RSA_digest_info_MD5[] = { + 0x30, 0x20, 0x30, 0x0C, 0x06, 0x08, + 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, /* OID */ + 0x05, 0x00, 0x04, 0x10 +}; + +static const u8 RSA_digest_info_SHA1[] = { + 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, + 0x2B, 0x0E, 0x03, 0x02, 0x1A, + 0x05, 0x00, 0x04, 0x14 +}; + +static const u8 RSA_digest_info_RIPE_MD_160[] = { + 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, + 0x2B, 0x24, 0x03, 0x02, 0x01, + 0x05, 0x00, 0x04, 0x14 +}; + +static const u8 RSA_digest_info_SHA224[] = { + 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, + 0x05, 0x00, 0x04, 0x1C +}; + +static const u8 RSA_digest_info_SHA256[] = { + 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, + 0x05, 0x00, 0x04, 0x20 +}; + +static const u8 RSA_digest_info_SHA384[] = { + 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, + 0x05, 0x00, 0x04, 0x30 +}; + +static const u8 RSA_digest_info_SHA512[] = { + 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, + 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, + 0x05, 0x00, 0x04, 0x40 +}; + +static const struct { + const u8 *data; + size_t size; +} RSA_ASN1_templates[PKEY_HASH__LAST] = { +#define _(X) { RSA_digest_info_##X, sizeof(RSA_digest_info_##X) } + [PKEY_HASH_MD5] = _(MD5), + [PKEY_HASH_SHA1] = _(SHA1), + [PKEY_HASH_RIPE_MD_160] = _(RIPE_MD_160), + [PKEY_HASH_SHA256] = _(SHA256), + [PKEY_HASH_SHA384] = _(SHA384), + [PKEY_HASH_SHA512] = _(SHA512), + [PKEY_HASH_SHA224] = _(SHA224), +#undef _ +}; + +/* + * RSAVP1() function [RFC3447 sec 5.2.2] + */ +static int RSAVP1(const struct public_key *key, MPI s, MPI *_m) +{ + MPI m; + int ret; + + /* (1) Validate 0 <= s < n */ + if (mpi_cmp_ui(s, 0) < 0) { + kleave(" = -EBADMSG [s < 0]"); + return -EBADMSG; + } + if (mpi_cmp(s, key->rsa.n) >= 0) { + kleave(" = -EBADMSG [s >= n]"); + return -EBADMSG; + } + + m = mpi_alloc(0); + if (!m) + return -ENOMEM; + + /* (2) m = s^e mod n */ + ret = mpi_powm(m, s, key->rsa.e, key->rsa.n); + if (ret < 0) { + mpi_free(m); + return ret; + } + + *_m = m; + return 0; +} + +/* + * Integer to Octet String conversion [RFC3447 sec 4.1] + */ +static int RSA_I2OSP(MPI x, size_t xLen, u8 **_X) +{ + unsigned X_size, x_size; + int X_sign; + u8 *X; + + /* Make sure the string is the right length. The number should begin + * with { 0x00, 0x01, ... } so we have to account for 15 leading zero + * bits not being reported by MPI. + */ + x_size = mpi_get_nbits(x); + pr_devel("size(x)=%u xLen*8=%zu\n", x_size, xLen * 8); + if (x_size != xLen * 8 - 15) + return -ERANGE; + + X = mpi_get_buffer(x, &X_size, &X_sign); + if (!X) + return -ENOMEM; + if (X_sign < 0) { + kfree(X); + return -EBADMSG; + } + if (X_size != xLen - 1) { + kfree(X); + return -EBADMSG; + } + + *_X = X; + return 0; +} + +/* + * Perform the RSA signature verification. + * @H: Value of hash of data and metadata + * @EM: The computed signature value + * @k: The size of EM (EM[0] is an invalid location but should hold 0x00) + * @hash_size: The size of H + * @asn1_template: The DigestInfo ASN.1 template + * @asn1_size: Size of asm1_template[] + */ +static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size, + const u8 *asn1_template, size_t asn1_size) +{ + unsigned PS_end, T_offset, i; + + kenter(",,%zu,%zu,%zu", k, hash_size, asn1_size); + + if (k < 2 + 1 + asn1_size + hash_size) + return -EBADMSG; + + /* Decode the EMSA-PKCS1-v1_5 */ + if (EM[1] != 0x01) { + kleave(" = -EBADMSG [EM[1] == %02u]", EM[1]); + return -EBADMSG; + } + + T_offset = k - (asn1_size + hash_size); + PS_end = T_offset - 1; + if (EM[PS_end] != 0x00) { + kleave(" = -EBADMSG [EM[T-1] == %02u]", EM[PS_end]); + return -EBADMSG; + } + + for (i = 2; i < PS_end; i++) { + if (EM[i] != 0xff) { + kleave(" = -EBADMSG [EM[PS%x] == %02u]", i - 2, EM[i]); + return -EBADMSG; + } + } + + if (memcmp(asn1_template, EM + T_offset, asn1_size) != 0) { + kleave(" = -EBADMSG [EM[T] ASN.1 mismatch]"); + return -EBADMSG; + } + + if (memcmp(H, EM + T_offset + asn1_size, hash_size) != 0) { + kleave(" = -EKEYREJECTED [EM[T] hash mismatch]"); + return -EKEYREJECTED; + } + + kleave(" = 0"); + return 0; +} + +/* + * Perform the verification step [RFC3447 sec 8.2.2]. + */ +static int RSA_verify_signature(const struct public_key *key, + const struct public_key_signature *sig) +{ + size_t tsize; + int ret; + + /* Variables as per RFC3447 sec 8.2.2 */ + const u8 *H = sig->digest; + u8 *EM = NULL; + MPI m = NULL; + size_t k; + + kenter(""); + + if (!RSA_ASN1_templates[sig->pkey_hash_algo].data) + return -ENOTSUPP; + + /* (1) Check the signature size against the public key modulus size */ + k = mpi_get_nbits(key->rsa.n); + tsize = mpi_get_nbits(sig->rsa.s); + + /* According to RFC 4880 sec 3.2, length of MPI is computed starting + * from most significant bit. So the RFC 3447 sec 8.2.2 size check + * must be relaxed to conform with shorter signatures - so we fail here + * only if signature length is longer than modulus size. + */ + pr_devel("step 1: k=%zu size(S)=%zu\n", k, tsize); + if (k < tsize) { + ret = -EBADMSG; + goto error; + } + + /* Round up and convert to octets */ + k = (k + 7) / 8; + + /* (2b) Apply the RSAVP1 verification primitive to the public key */ + ret = RSAVP1(key, sig->rsa.s, &m); + if (ret < 0) + goto error; + + /* (2c) Convert the message representative (m) to an encoded message + * (EM) of length k octets. + * + * NOTE! The leading zero byte is suppressed by MPI, so we pass a + * pointer to the _preceding_ byte to RSA_verify()! + */ + ret = RSA_I2OSP(m, k, &EM); + if (ret < 0) + goto error; + + ret = RSA_verify(H, EM - 1, k, sig->digest_size, + RSA_ASN1_templates[sig->pkey_hash_algo].data, + RSA_ASN1_templates[sig->pkey_hash_algo].size); + +error: + kfree(EM); + mpi_free(m); + kleave(" = %d", ret); + return ret; +} + +const struct public_key_algorithm RSA_public_key_algorithm = { + .name = "RSA", + .n_pub_mpi = 2, + .n_sec_mpi = 3, + .n_sig_mpi = 1, + .verify_signature = RSA_verify_signature, +}; +EXPORT_SYMBOL_GPL(RSA_public_key_algorithm); diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c new file mode 100644 index 00000000000..50b3f880b4f --- /dev/null +++ b/crypto/asymmetric_keys/signature.c @@ -0,0 +1,49 @@ +/* Signature verification with an asymmetric key + * + * See Documentation/security/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 <keys/asymmetric-subtype.h> +#include <linux/module.h> +#include <linux/err.h> +#include <crypto/public_key.h> +#include "asymmetric_keys.h" + +/** + * verify_signature - Initiate the use of an asymmetric key to verify a signature + * @key: The asymmetric key to verify against + * @sig: The signature to check + * + * Returns 0 if successful or else an error. + */ +int verify_signature(const struct key *key, + const struct public_key_signature *sig) +{ + const struct asymmetric_key_subtype *subtype; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (key->type != &key_type_asymmetric) + return -EINVAL; + subtype = asymmetric_key_subtype(key); + if (!subtype || + !key->payload.data) + return -EINVAL; + if (!subtype->verify_signature) + return -ENOTSUPP; + + ret = subtype->verify_signature(key, sig); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(verify_signature); diff --git a/crypto/asymmetric_keys/x509.asn1 b/crypto/asymmetric_keys/x509.asn1 new file mode 100644 index 00000000000..bf32b3dff08 --- /dev/null +++ b/crypto/asymmetric_keys/x509.asn1 @@ -0,0 +1,60 @@ +Certificate ::= SEQUENCE { + tbsCertificate TBSCertificate ({ x509_note_tbs_certificate }), + signatureAlgorithm AlgorithmIdentifier, + signature BIT STRING ({ x509_note_signature }) + } + +TBSCertificate ::= SEQUENCE { + version [ 0 ] Version DEFAULT, + serialNumber CertificateSerialNumber, + signature AlgorithmIdentifier ({ x509_note_pkey_algo }), + issuer Name ({ x509_note_issuer }), + validity Validity, + subject Name ({ x509_note_subject }), + subjectPublicKeyInfo SubjectPublicKeyInfo, + issuerUniqueID [ 1 ] IMPLICIT UniqueIdentifier OPTIONAL, + subjectUniqueID [ 2 ] IMPLICIT UniqueIdentifier OPTIONAL, + extensions [ 3 ] Extensions OPTIONAL + } + +Version ::= INTEGER +CertificateSerialNumber ::= INTEGER + +AlgorithmIdentifier ::= SEQUENCE { + algorithm OBJECT IDENTIFIER ({ x509_note_OID }), + parameters ANY OPTIONAL +} + +Name ::= SEQUENCE OF RelativeDistinguishedName + +RelativeDistinguishedName ::= SET OF AttributeValueAssertion + +AttributeValueAssertion ::= SEQUENCE { + attributeType OBJECT IDENTIFIER ({ x509_note_OID }), + attributeValue ANY ({ x509_extract_name_segment }) + } + +Validity ::= SEQUENCE { + notBefore Time ({ x509_note_not_before }), + notAfter Time ({ x509_note_not_after }) + } + +Time ::= CHOICE { + utcTime UTCTime, + generalTime GeneralizedTime + } + +SubjectPublicKeyInfo ::= SEQUENCE { + algorithm AlgorithmIdentifier, + subjectPublicKey BIT STRING ({ x509_extract_key_data }) + } + +UniqueIdentifier ::= BIT STRING + +Extensions ::= SEQUENCE OF Extension + +Extension ::= SEQUENCE { + extnid OBJECT IDENTIFIER ({ x509_note_OID }), + critical BOOLEAN DEFAULT, + extnValue OCTET STRING ({ x509_process_extension }) + } diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c new file mode 100644 index 00000000000..7fabc4c0199 --- /dev/null +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -0,0 +1,496 @@ +/* X.509 certificate parser + * + * 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) "X.509: "fmt +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/oid_registry.h> +#include "public_key.h" +#include "x509_parser.h" +#include "x509-asn1.h" +#include "x509_rsakey-asn1.h" + +struct x509_parse_context { + struct x509_certificate *cert; /* Certificate being constructed */ + unsigned long data; /* Start of data */ + const void *cert_start; /* Start of cert content */ + const void *key; /* Key data */ + size_t key_size; /* Size of key data */ + enum OID last_oid; /* Last OID encountered */ + enum OID algo_oid; /* Algorithm OID */ + unsigned char nr_mpi; /* Number of MPIs stored */ + u8 o_size; /* Size of organizationName (O) */ + u8 cn_size; /* Size of commonName (CN) */ + u8 email_size; /* Size of emailAddress */ + u16 o_offset; /* Offset of organizationName (O) */ + u16 cn_offset; /* Offset of commonName (CN) */ + u16 email_offset; /* Offset of emailAddress */ +}; + +/* + * Free an X.509 certificate + */ +void x509_free_certificate(struct x509_certificate *cert) +{ + if (cert) { + public_key_destroy(cert->pub); + kfree(cert->issuer); + kfree(cert->subject); + kfree(cert->fingerprint); + kfree(cert->authority); + kfree(cert); + } +} + +/* + * Parse an X.509 certificate + */ +struct x509_certificate *x509_cert_parse(const void *data, size_t datalen) +{ + struct x509_certificate *cert; + struct x509_parse_context *ctx; + long ret; + + ret = -ENOMEM; + cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL); + if (!cert) + goto error_no_cert; + cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL); + if (!cert->pub) + goto error_no_ctx; + ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL); + if (!ctx) + goto error_no_ctx; + + ctx->cert = cert; + ctx->data = (unsigned long)data; + + /* Attempt to decode the certificate */ + ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen); + if (ret < 0) + goto error_decode; + + /* Decode the public key */ + ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx, + ctx->key, ctx->key_size); + if (ret < 0) + goto error_decode; + + kfree(ctx); + return cert; + +error_decode: + kfree(ctx); +error_no_ctx: + x509_free_certificate(cert); +error_no_cert: + return ERR_PTR(ret); +} + +/* + * Note an OID when we find one for later processing when we know how + * to interpret it. + */ +int x509_note_OID(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + + ctx->last_oid = look_up_OID(value, vlen); + if (ctx->last_oid == OID__NR) { + char buffer[50]; + sprint_oid(value, vlen, buffer, sizeof(buffer)); + pr_debug("Unknown OID: [%lu] %s\n", + (unsigned long)value - ctx->data, buffer); + } + return 0; +} + +/* + * Save the position of the TBS data so that we can check the signature over it + * later. + */ +int x509_note_tbs_certificate(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + + pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n", + hdrlen, tag, (unsigned long)value - ctx->data, vlen); + + ctx->cert->tbs = value - hdrlen; + ctx->cert->tbs_size = vlen + hdrlen; + return 0; +} + +/* + * Record the public key algorithm + */ +int x509_note_pkey_algo(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + + pr_debug("PubKey Algo: %u\n", ctx->last_oid); + + switch (ctx->last_oid) { + case OID_md2WithRSAEncryption: + case OID_md3WithRSAEncryption: + default: + return -ENOPKG; /* Unsupported combination */ + + case OID_md4WithRSAEncryption: + ctx->cert->sig_hash_algo = PKEY_HASH_MD5; + ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + break; + + case OID_sha1WithRSAEncryption: + ctx->cert->sig_hash_algo = PKEY_HASH_SHA1; + ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + break; + + case OID_sha256WithRSAEncryption: + ctx->cert->sig_hash_algo = PKEY_HASH_SHA256; + ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + break; + + case OID_sha384WithRSAEncryption: + ctx->cert->sig_hash_algo = PKEY_HASH_SHA384; + ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + break; + + case OID_sha512WithRSAEncryption: + ctx->cert->sig_hash_algo = PKEY_HASH_SHA512; + ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + break; + + case OID_sha224WithRSAEncryption: + ctx->cert->sig_hash_algo = PKEY_HASH_SHA224; + ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + break; + } + + ctx->algo_oid = ctx->last_oid; + return 0; +} + +/* + * Note the whereabouts and type of the signature. + */ +int x509_note_signature(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + + pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen); + + if (ctx->last_oid != ctx->algo_oid) { + pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n", + ctx->algo_oid, ctx->last_oid); + return -EINVAL; + } + + ctx->cert->sig = value; + ctx->cert->sig_size = vlen; + return 0; +} + +/* + * Note some of the name segments from which we'll fabricate a name. + */ +int x509_extract_name_segment(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + + switch (ctx->last_oid) { + case OID_commonName: + ctx->cn_size = vlen; + ctx->cn_offset = (unsigned long)value - ctx->data; + break; + case OID_organizationName: + ctx->o_size = vlen; + ctx->o_offset = (unsigned long)value - ctx->data; + break; + case OID_email_address: + ctx->email_size = vlen; + ctx->email_offset = (unsigned long)value - ctx->data; + break; + default: + break; + } + + return 0; +} + +/* + * Fabricate and save the issuer and subject names + */ +static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen, + unsigned char tag, + char **_name, size_t vlen) +{ + const void *name, *data = (const void *)ctx->data; + size_t namesize; + char *buffer; + + if (*_name) + return -EINVAL; + + /* Empty name string if no material */ + if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) { + buffer = kmalloc(1, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + buffer[0] = 0; + goto done; + } + + if (ctx->cn_size && ctx->o_size) { + /* Consider combining O and CN, but use only the CN if it is + * prefixed by the O, or a significant portion thereof. + */ + namesize = ctx->cn_size; + name = data + ctx->cn_offset; + if (ctx->cn_size >= ctx->o_size && + memcmp(data + ctx->cn_offset, data + ctx->o_offset, + ctx->o_size) == 0) + goto single_component; + if (ctx->cn_size >= 7 && + ctx->o_size >= 7 && + memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0) + goto single_component; + + buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1, + GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + memcpy(buffer, + data + ctx->o_offset, ctx->o_size); + buffer[ctx->o_size + 0] = ':'; + buffer[ctx->o_size + 1] = ' '; + memcpy(buffer + ctx->o_size + 2, + data + ctx->cn_offset, ctx->cn_size); + buffer[ctx->o_size + 2 + ctx->cn_size] = 0; + goto done; + + } else if (ctx->cn_size) { + namesize = ctx->cn_size; + name = data + ctx->cn_offset; + } else if (ctx->o_size) { + namesize = ctx->o_size; + name = data + ctx->o_offset; + } else { + namesize = ctx->email_size; + name = data + ctx->email_offset; + } + +single_component: + buffer = kmalloc(namesize + 1, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + memcpy(buffer, name, namesize); + buffer[namesize] = 0; + +done: + *_name = buffer; + ctx->cn_size = 0; + ctx->o_size = 0; + ctx->email_size = 0; + return 0; +} + +int x509_note_issuer(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen); +} + +int x509_note_subject(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen); +} + +/* + * Extract the data for the public key algorithm + */ +int x509_extract_key_data(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + + if (ctx->last_oid != OID_rsaEncryption) + return -ENOPKG; + + /* There seems to be an extraneous 0 byte on the front of the data */ + ctx->cert->pkey_algo = PKEY_ALGO_RSA; + ctx->key = value + 1; + ctx->key_size = vlen - 1; + return 0; +} + +/* + * Extract a RSA public key value + */ +int rsa_extract_mpi(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + MPI mpi; + + if (ctx->nr_mpi >= ARRAY_SIZE(ctx->cert->pub->mpi)) { + pr_err("Too many public key MPIs in certificate\n"); + return -EBADMSG; + } + + mpi = mpi_read_raw_data(value, vlen); + if (!mpi) + return -ENOMEM; + + ctx->cert->pub->mpi[ctx->nr_mpi++] = mpi; + return 0; +} + +/* + * Process certificate extensions that are used to qualify the certificate. + */ +int x509_process_extension(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + const unsigned char *v = value; + char *f; + int i; + + pr_debug("Extension: %u\n", ctx->last_oid); + + if (ctx->last_oid == OID_subjectKeyIdentifier) { + /* Get hold of the key fingerprint */ + if (vlen < 3) + return -EBADMSG; + if (v[0] != ASN1_OTS || v[1] != vlen - 2) + return -EBADMSG; + v += 2; + vlen -= 2; + + f = kmalloc(vlen * 2 + 1, GFP_KERNEL); + if (!f) + return -ENOMEM; + for (i = 0; i < vlen; i++) + sprintf(f + i * 2, "%02x", v[i]); + pr_debug("fingerprint %s\n", f); + ctx->cert->fingerprint = f; + return 0; + } + + if (ctx->last_oid == OID_authorityKeyIdentifier) { + /* Get hold of the CA key fingerprint */ + if (vlen < 5) + return -EBADMSG; + if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)) || + v[1] != vlen - 2 || + v[2] != (ASN1_CONT << 6) || + v[3] != vlen - 4) + return -EBADMSG; + v += 4; + vlen -= 4; + + f = kmalloc(vlen * 2 + 1, GFP_KERNEL); + if (!f) + return -ENOMEM; + for (i = 0; i < vlen; i++) + sprintf(f + i * 2, "%02x", v[i]); + pr_debug("authority %s\n", f); + ctx->cert->authority = f; + return 0; + } + + return 0; +} + +/* + * Record a certificate time. + */ +static int x509_note_time(struct tm *tm, size_t hdrlen, + unsigned char tag, + const unsigned char *value, size_t vlen) +{ + const unsigned char *p = value; + +#define dec2bin(X) ((X) - '0') +#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; }) + + if (tag == ASN1_UNITIM) { + /* UTCTime: YYMMDDHHMMSSZ */ + if (vlen != 13) + goto unsupported_time; + tm->tm_year = DD2bin(p); + if (tm->tm_year >= 50) + tm->tm_year += 1900; + else + tm->tm_year += 2000; + } else if (tag == ASN1_GENTIM) { + /* GenTime: YYYYMMDDHHMMSSZ */ + if (vlen != 15) + goto unsupported_time; + tm->tm_year = DD2bin(p) * 100 + DD2bin(p); + } else { + goto unsupported_time; + } + + tm->tm_year -= 1900; + tm->tm_mon = DD2bin(p) - 1; + tm->tm_mday = DD2bin(p); + tm->tm_hour = DD2bin(p); + tm->tm_min = DD2bin(p); + tm->tm_sec = DD2bin(p); + + if (*p != 'Z') + goto unsupported_time; + + return 0; + +unsupported_time: + pr_debug("Got unsupported time [tag %02x]: '%*.*s'\n", + tag, (int)vlen, (int)vlen, value); + return -EBADMSG; +} + +int x509_note_not_before(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + return x509_note_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen); +} + +int x509_note_not_after(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct x509_parse_context *ctx = context; + return x509_note_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen); +} diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h new file mode 100644 index 00000000000..f86dc5fcc4a --- /dev/null +++ b/crypto/asymmetric_keys/x509_parser.h @@ -0,0 +1,36 @@ +/* X.509 certificate parser internal definitions + * + * 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 <crypto/public_key.h> + +struct x509_certificate { + struct x509_certificate *next; + struct public_key *pub; /* Public key details */ + char *issuer; /* Name of certificate issuer */ + char *subject; /* Name of certificate subject */ + char *fingerprint; /* Key fingerprint as hex */ + char *authority; /* Authority key fingerprint as hex */ + struct tm valid_from; + struct tm valid_to; + enum pkey_algo pkey_algo : 8; /* Public key algorithm */ + enum pkey_algo sig_pkey_algo : 8; /* Signature public key algorithm */ + enum pkey_hash_algo sig_hash_algo : 8; /* Signature hash algorithm */ + const void *tbs; /* Signed data */ + size_t tbs_size; /* Size of signed data */ + const void *sig; /* Signature data */ + size_t sig_size; /* Size of sigature */ +}; + +/* + * x509_cert_parser.c + */ +extern void x509_free_certificate(struct x509_certificate *cert); +extern struct x509_certificate *x509_cert_parse(const void *data, size_t datalen); diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c new file mode 100644 index 00000000000..06007f0e880 --- /dev/null +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -0,0 +1,239 @@ +/* Instantiate a public key crypto key from an X.509 Certificate + * + * 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) "X.509: "fmt +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/mpi.h> +#include <linux/asn1_decoder.h> +#include <keys/asymmetric-subtype.h> +#include <keys/asymmetric-parser.h> +#include <crypto/hash.h> +#include "asymmetric_keys.h" +#include "public_key.h" +#include "x509_parser.h" + +static const +struct public_key_algorithm *x509_public_key_algorithms[PKEY_ALGO__LAST] = { + [PKEY_ALGO_DSA] = NULL, +#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \ + defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE) + [PKEY_ALGO_RSA] = &RSA_public_key_algorithm, +#endif +}; + +/* + * Check the signature on a certificate using the provided public key + */ +static int x509_check_signature(const struct public_key *pub, + const struct x509_certificate *cert) +{ + struct public_key_signature *sig; + struct crypto_shash *tfm; + struct shash_desc *desc; + size_t digest_size, desc_size; + int ret; + + pr_devel("==>%s()\n", __func__); + + /* Allocate the hashing algorithm we're going to need and find out how + * big the hash operational data will be. + */ + tfm = crypto_alloc_shash(pkey_hash_algo[cert->sig_hash_algo], 0, 0); + if (IS_ERR(tfm)) + return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm); + + desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); + digest_size = crypto_shash_digestsize(tfm); + + /* We allocate the hash operational data storage on the end of our + * context data. + */ + ret = -ENOMEM; + sig = kzalloc(sizeof(*sig) + desc_size + digest_size, GFP_KERNEL); + if (!sig) + goto error_no_sig; + + sig->pkey_hash_algo = cert->sig_hash_algo; + sig->digest = (u8 *)sig + sizeof(*sig) + desc_size; + sig->digest_size = digest_size; + + desc = (void *)sig + sizeof(*sig); + desc->tfm = tfm; + desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + ret = crypto_shash_init(desc); + if (ret < 0) + goto error; + + ret = -ENOMEM; + sig->rsa.s = mpi_read_raw_data(cert->sig, cert->sig_size); + if (!sig->rsa.s) + goto error; + + ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, sig->digest); + if (ret < 0) + goto error_mpi; + + ret = pub->algo->verify_signature(pub, sig); + + pr_debug("Cert Verification: %d\n", ret); + +error_mpi: + mpi_free(sig->rsa.s); +error: + kfree(sig); +error_no_sig: + crypto_free_shash(tfm); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* + * Attempt to parse a data blob for a key as an X509 certificate. + */ +static int x509_key_preparse(struct key_preparsed_payload *prep) +{ + struct x509_certificate *cert; + struct tm now; + size_t srlen, sulen; + char *desc = NULL; + int ret; + + cert = x509_cert_parse(prep->data, prep->datalen); + if (IS_ERR(cert)) + return PTR_ERR(cert); + + pr_devel("Cert Issuer: %s\n", cert->issuer); + pr_devel("Cert Subject: %s\n", cert->subject); + pr_devel("Cert Key Algo: %s\n", pkey_algo[cert->pkey_algo]); + pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n", + cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1, + cert->valid_from.tm_mday, cert->valid_from.tm_hour, + cert->valid_from.tm_min, cert->valid_from.tm_sec); + pr_devel("Cert Valid To: %04ld-%02d-%02d %02d:%02d:%02d\n", + cert->valid_to.tm_year + 1900, cert->valid_to.tm_mon + 1, + cert->valid_to.tm_mday, cert->valid_to.tm_hour, + cert->valid_to.tm_min, cert->valid_to.tm_sec); + pr_devel("Cert Signature: %s + %s\n", + pkey_algo[cert->sig_pkey_algo], + pkey_hash_algo[cert->sig_hash_algo]); + + if (!cert->fingerprint || !cert->authority) { + pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n", + cert->subject); + ret = -EKEYREJECTED; + goto error_free_cert; + } + + time_to_tm(CURRENT_TIME.tv_sec, 0, &now); + pr_devel("Now: %04ld-%02d-%02d %02d:%02d:%02d\n", + now.tm_year + 1900, now.tm_mon + 1, now.tm_mday, + now.tm_hour, now.tm_min, now.tm_sec); + if (now.tm_year < cert->valid_from.tm_year || + (now.tm_year == cert->valid_from.tm_year && + (now.tm_mon < cert->valid_from.tm_mon || + (now.tm_mon == cert->valid_from.tm_mon && + (now.tm_mday < cert->valid_from.tm_mday || + (now.tm_mday == cert->valid_from.tm_mday && + (now.tm_hour < cert->valid_from.tm_hour || + (now.tm_hour == cert->valid_from.tm_hour && + (now.tm_min < cert->valid_from.tm_min || + (now.tm_min == cert->valid_from.tm_min && + (now.tm_sec < cert->valid_from.tm_sec + ))))))))))) { + pr_warn("Cert %s is not yet valid\n", cert->fingerprint); + ret = -EKEYREJECTED; + goto error_free_cert; + } + if (now.tm_year > cert->valid_to.tm_year || + (now.tm_year == cert->valid_to.tm_year && + (now.tm_mon > cert->valid_to.tm_mon || + (now.tm_mon == cert->valid_to.tm_mon && + (now.tm_mday > cert->valid_to.tm_mday || + (now.tm_mday == cert->valid_to.tm_mday && + (now.tm_hour > cert->valid_to.tm_hour || + (now.tm_hour == cert->valid_to.tm_hour && + (now.tm_min > cert->valid_to.tm_min || + (now.tm_min == cert->valid_to.tm_min && + (now.tm_sec > cert->valid_to.tm_sec + ))))))))))) { + pr_warn("Cert %s has expired\n", cert->fingerprint); + ret = -EKEYEXPIRED; + goto error_free_cert; + } + + cert->pub->algo = x509_public_key_algorithms[cert->pkey_algo]; + cert->pub->id_type = PKEY_ID_X509; + + /* Check the signature on the key */ + if (strcmp(cert->fingerprint, cert->authority) == 0) { + ret = x509_check_signature(cert->pub, cert); + if (ret < 0) + goto error_free_cert; + } + + /* Propose a description */ + sulen = strlen(cert->subject); + srlen = strlen(cert->fingerprint); + ret = -ENOMEM; + desc = kmalloc(sulen + 2 + srlen + 1, GFP_KERNEL); + if (!desc) + goto error_free_cert; + memcpy(desc, cert->subject, sulen); + desc[sulen] = ':'; + desc[sulen + 1] = ' '; + memcpy(desc + sulen + 2, cert->fingerprint, srlen); + desc[sulen + 2 + srlen] = 0; + + /* We're pinning the module by being linked against it */ + __module_get(public_key_subtype.owner); + prep->type_data[0] = &public_key_subtype; + prep->type_data[1] = cert->fingerprint; + prep->payload = cert->pub; + prep->description = desc; + prep->quotalen = 100; + + /* We've finished with the certificate */ + cert->pub = NULL; + cert->fingerprint = NULL; + desc = NULL; + ret = 0; + +error_free_cert: + x509_free_certificate(cert); + return ret; +} + +static struct asymmetric_key_parser x509_key_parser = { + .owner = THIS_MODULE, + .name = "x509", + .parse = x509_key_preparse, +}; + +/* + * Module stuff + */ +static int __init x509_key_init(void) +{ + return register_asymmetric_key_parser(&x509_key_parser); +} + +static void __exit x509_key_exit(void) +{ + unregister_asymmetric_key_parser(&x509_key_parser); +} + +module_init(x509_key_init); +module_exit(x509_key_exit); diff --git a/crypto/asymmetric_keys/x509_rsakey.asn1 b/crypto/asymmetric_keys/x509_rsakey.asn1 new file mode 100644 index 00000000000..4ec7cc6532c --- /dev/null +++ b/crypto/asymmetric_keys/x509_rsakey.asn1 @@ -0,0 +1,4 @@ +RSAPublicKey ::= SEQUENCE { + modulus INTEGER ({ rsa_extract_mpi }), -- n + publicExponent INTEGER ({ rsa_extract_mpi }) -- e + } |