From 3b764563177c1e435ef3e2608271c07955f73ea6 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 6 Apr 2016 16:13:33 +0100 Subject: KEYS: Allow authentication data to be stored in an asymmetric key Allow authentication data to be stored in an asymmetric key in the 4th element of the key payload and provide a way for it to be destroyed. For the public key subtype, this will be a public_key_signature struct. Signed-off-by: David Howells --- include/crypto/public_key.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/crypto') diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index aa730ea7faf8..19f557ca50ba 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -41,7 +41,7 @@ struct public_key { const char *pkey_algo; }; -extern void public_key_destroy(void *payload); +extern void public_key_free(struct public_key *key); /* * Public key cryptography signature data @@ -55,7 +55,10 @@ struct public_key_signature { const char *hash_algo; }; +extern void public_key_signature_free(struct public_key_signature *sig); + extern struct asymmetric_key_subtype public_key_subtype; + struct key; extern int verify_signature(const struct key *key, const struct public_key_signature *sig); -- cgit v1.3-14-g43fede From a022ec02691cf68e1fe237d5f79d54aa95446cc6 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 6 Apr 2016 16:13:33 +0100 Subject: KEYS: Add identifier pointers to public_key_signature struct Add key identifier pointers to public_key_signature struct so that they can be used to retain the identifier of the key to be used to verify the signature in both PKCS#7 and X.509. Signed-off-by: David Howells --- crypto/asymmetric_keys/signature.c | 4 ++++ include/crypto/public_key.h | 1 + 2 files changed, 5 insertions(+) (limited to 'include/crypto') diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c index 3beee3976ed5..11b7ba170904 100644 --- a/crypto/asymmetric_keys/signature.c +++ b/crypto/asymmetric_keys/signature.c @@ -24,7 +24,11 @@ */ void public_key_signature_free(struct public_key_signature *sig) { + int i; + if (sig) { + for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++) + kfree(sig->auth_ids[i]); kfree(sig->s); kfree(sig->digest); kfree(sig); diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 19f557ca50ba..2f5de5c1a3a0 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -47,6 +47,7 @@ extern void public_key_free(struct public_key *key); * Public key cryptography signature data */ struct public_key_signature { + struct asymmetric_key_id *auth_ids[2]; u8 *s; /* Signature */ u32 s_size; /* Number of bytes in signature */ u8 *digest; -- cgit v1.3-14-g43fede From e68503bd6836ba765dc8e0ee77ea675fedc07e41 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 6 Apr 2016 16:14:24 +0100 Subject: KEYS: Generalise system_verify_data() to provide access to internal content Generalise system_verify_data() to provide access to internal content through a callback. This allows all the PKCS#7 stuff to be hidden inside this function and removed from the PE file parser and the PKCS#7 test key. If external content is not required, NULL should be passed as data to the function. If the callback is not required, that can be set to NULL. The function is now called verify_pkcs7_signature() to contrast with verify_pefile_signature() and the definitions of both have been moved into linux/verification.h along with the key_being_used_for enum. Signed-off-by: David Howells --- arch/x86/kernel/kexec-bzimage64.c | 18 ++------- certs/system_keyring.c | 45 ++++++++++++++++----- crypto/asymmetric_keys/Kconfig | 4 +- crypto/asymmetric_keys/mscode_parser.c | 21 ++++------ crypto/asymmetric_keys/pkcs7_key_type.c | 72 +++++++++++++-------------------- crypto/asymmetric_keys/pkcs7_parser.c | 21 +++++----- crypto/asymmetric_keys/verify_pefile.c | 40 +++++------------- crypto/asymmetric_keys/verify_pefile.h | 5 +-- include/crypto/pkcs7.h | 3 +- include/crypto/public_key.h | 14 ------- include/keys/asymmetric-type.h | 1 + include/keys/system_keyring.h | 7 +--- include/linux/verification.h | 50 +++++++++++++++++++++++ include/linux/verify_pefile.h | 22 ---------- kernel/module_signing.c | 5 ++- 15 files changed, 155 insertions(+), 173 deletions(-) create mode 100644 include/linux/verification.h delete mode 100644 include/linux/verify_pefile.h (limited to 'include/crypto') diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index 2af478e3fd4e..f2356bda2b05 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -19,8 +19,7 @@ #include #include #include -#include -#include +#include #include #include @@ -529,18 +528,9 @@ static int bzImage64_cleanup(void *loader_data) #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len) { - bool trusted; - int ret; - - ret = verify_pefile_signature(kernel, kernel_len, - system_trusted_keyring, - VERIFYING_KEXEC_PE_SIGNATURE, - &trusted); - if (ret < 0) - return ret; - if (!trusted) - return -EKEYREJECTED; - return 0; + return verify_pefile_signature(kernel, kernel_len, + NULL, + VERIFYING_KEXEC_PE_SIGNATURE); } #endif diff --git a/certs/system_keyring.c b/certs/system_keyring.c index f4180326c2e1..a83bffedc0aa 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -108,16 +108,25 @@ late_initcall(load_system_certificate_list); #ifdef CONFIG_SYSTEM_DATA_VERIFICATION /** - * Verify a PKCS#7-based signature on system data. - * @data: The data to be verified. + * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data. + * @data: The data to be verified (NULL if expecting internal data). * @len: Size of @data. * @raw_pkcs7: The PKCS#7 message that is the signature. * @pkcs7_len: The size of @raw_pkcs7. + * @trusted_keys: Trusted keys to use (NULL for system_trusted_keyring). * @usage: The use to which the key is being put. + * @view_content: Callback to gain access to content. + * @ctx: Context for callback. */ -int system_verify_data(const void *data, unsigned long len, - const void *raw_pkcs7, size_t pkcs7_len, - enum key_being_used_for usage) +int verify_pkcs7_signature(const void *data, size_t len, + const void *raw_pkcs7, size_t pkcs7_len, + struct key *trusted_keys, + int untrusted_error, + enum key_being_used_for usage, + int (*view_content)(void *ctx, + const void *data, size_t len, + size_t asn1hdrlen), + void *ctx) { struct pkcs7_message *pkcs7; bool trusted; @@ -128,7 +137,7 @@ int system_verify_data(const void *data, unsigned long len, return PTR_ERR(pkcs7); /* The data should be detached - so we need to supply it. */ - if (pkcs7_supply_detached_data(pkcs7, data, len) < 0) { + if (data && pkcs7_supply_detached_data(pkcs7, data, len) < 0) { pr_err("PKCS#7 signature with non-detached data\n"); ret = -EBADMSG; goto error; @@ -138,13 +147,29 @@ int system_verify_data(const void *data, unsigned long len, if (ret < 0) goto error; - ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted); + if (!trusted_keys) + trusted_keys = system_trusted_keyring; + ret = pkcs7_validate_trust(pkcs7, trusted_keys, &trusted); if (ret < 0) goto error; - if (!trusted) { + if (!trusted && untrusted_error) { pr_err("PKCS#7 signature not signed with a trusted key\n"); - ret = -ENOKEY; + ret = untrusted_error; + goto error; + } + + if (view_content) { + size_t asn1hdrlen; + + ret = pkcs7_get_content_data(pkcs7, &data, &len, &asn1hdrlen); + if (ret < 0) { + if (ret == -ENODATA) + pr_devel("PKCS#7 message does not contain data\n"); + goto error; + } + + ret = view_content(ctx, data, len, asn1hdrlen); } error: @@ -152,6 +177,6 @@ error: pr_devel("<==%s() = %d\n", __func__, ret); return ret; } -EXPORT_SYMBOL_GPL(system_verify_data); +EXPORT_SYMBOL_GPL(verify_pkcs7_signature); #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig index 91a7e047a765..f7d2ef9789d8 100644 --- a/crypto/asymmetric_keys/Kconfig +++ b/crypto/asymmetric_keys/Kconfig @@ -40,8 +40,7 @@ config PKCS7_MESSAGE_PARSER config PKCS7_TEST_KEY tristate "PKCS#7 testing key type" - depends on PKCS7_MESSAGE_PARSER - select SYSTEM_TRUSTED_KEYRING + depends on SYSTEM_DATA_VERIFICATION help This option provides a type of key that can be loaded up from a PKCS#7 message - provided the message is signed by a trusted key. If @@ -54,6 +53,7 @@ config PKCS7_TEST_KEY config SIGNED_PE_FILE_VERIFICATION bool "Support for PE file signature verification" depends on PKCS7_MESSAGE_PARSER=y + depends on SYSTEM_DATA_VERIFICATION select ASN1 select OID_REGISTRY help diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c index 3242cbfaeaa2..6a76d5c70ef6 100644 --- a/crypto/asymmetric_keys/mscode_parser.c +++ b/crypto/asymmetric_keys/mscode_parser.c @@ -21,19 +21,13 @@ /* * Parse a Microsoft Individual Code Signing blob */ -int mscode_parse(struct pefile_context *ctx) +int mscode_parse(void *_ctx, const void *content_data, size_t data_len, + size_t asn1hdrlen) { - const void *content_data; - size_t data_len; - int ret; - - ret = pkcs7_get_content_data(ctx->pkcs7, &content_data, &data_len, 1); - - if (ret) { - pr_debug("PKCS#7 message does not contain data\n"); - return ret; - } + struct pefile_context *ctx = _ctx; + content_data -= asn1hdrlen; + data_len += asn1hdrlen; pr_devel("Data: %zu [%*ph]\n", data_len, (unsigned)(data_len), content_data); @@ -129,7 +123,6 @@ int mscode_note_digest(void *context, size_t hdrlen, { struct pefile_context *ctx = context; - ctx->digest = value; - ctx->digest_len = vlen; - return 0; + ctx->digest = kmemdup(value, vlen, GFP_KERNEL); + return ctx->digest ? 0 : -ENOMEM; } diff --git a/crypto/asymmetric_keys/pkcs7_key_type.c b/crypto/asymmetric_keys/pkcs7_key_type.c index e2d0edbbc71a..ab9bf5363ecd 100644 --- a/crypto/asymmetric_keys/pkcs7_key_type.c +++ b/crypto/asymmetric_keys/pkcs7_key_type.c @@ -13,12 +13,9 @@ #include #include #include +#include #include -#include -#include #include -#include -#include "pkcs7_parser.h" MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("PKCS#7 testing key type"); @@ -29,59 +26,46 @@ MODULE_PARM_DESC(pkcs7_usage, "Usage to specify when verifying the PKCS#7 message"); /* - * Preparse a PKCS#7 wrapped and validated data blob. + * Retrieve the PKCS#7 message content. */ -static int pkcs7_preparse(struct key_preparsed_payload *prep) +static int pkcs7_view_content(void *ctx, const void *data, size_t len, + size_t asn1hdrlen) { - enum key_being_used_for usage = pkcs7_usage; - struct pkcs7_message *pkcs7; - const void *data, *saved_prep_data; - size_t datalen, saved_prep_datalen; - bool trusted; + struct key_preparsed_payload *prep = ctx; + const void *saved_prep_data; + size_t saved_prep_datalen; int ret; - kenter(""); - - if (usage >= NR__KEY_BEING_USED_FOR) { - pr_err("Invalid usage type %d\n", usage); - return -EINVAL; - } - saved_prep_data = prep->data; saved_prep_datalen = prep->datalen; - pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen); - if (IS_ERR(pkcs7)) { - ret = PTR_ERR(pkcs7); - goto error; - } - - ret = pkcs7_verify(pkcs7, usage); - if (ret < 0) - goto error_free; - - ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted); - if (ret < 0) - goto error_free; - if (!trusted) - pr_warn("PKCS#7 message doesn't chain back to a trusted key\n"); - - ret = pkcs7_get_content_data(pkcs7, &data, &datalen, false); - if (ret < 0) - goto error_free; - prep->data = data; - prep->datalen = datalen; + prep->datalen = len; + ret = user_preparse(prep); + prep->data = saved_prep_data; prep->datalen = saved_prep_datalen; - -error_free: - pkcs7_free_message(pkcs7); -error: - kleave(" = %d", ret); return ret; } +/* + * Preparse a PKCS#7 wrapped and validated data blob. + */ +static int pkcs7_preparse(struct key_preparsed_payload *prep) +{ + enum key_being_used_for usage = pkcs7_usage; + + if (usage >= NR__KEY_BEING_USED_FOR) { + pr_err("Invalid usage type %d\n", usage); + return -EINVAL; + } + + return verify_pkcs7_signature(NULL, 0, + prep->data, prep->datalen, + NULL, -ENOKEY, usage, + pkcs7_view_content, prep); +} + /* * user defined keys take an arbitrary string as the description and an * arbitrary blob of data as the payload diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c index 835701613125..af4cd8649117 100644 --- a/crypto/asymmetric_keys/pkcs7_parser.c +++ b/crypto/asymmetric_keys/pkcs7_parser.c @@ -168,24 +168,25 @@ EXPORT_SYMBOL_GPL(pkcs7_parse_message); * @pkcs7: The preparsed PKCS#7 message to access * @_data: Place to return a pointer to the data * @_data_len: Place to return the data length - * @want_wrapper: True if the ASN.1 object header should be included in the data + * @_headerlen: Size of ASN.1 header not included in _data * - * Get access to the data content of the PKCS#7 message, including, optionally, - * the header of the ASN.1 object that contains it. Returns -ENODATA if the - * data object was missing from the message. + * Get access to the data content of the PKCS#7 message. The size of the + * header of the ASN.1 object that contains it is also provided and can be used + * to adjust *_data and *_data_len to get the entire object. + * + * Returns -ENODATA if the data object was missing from the message. */ int pkcs7_get_content_data(const struct pkcs7_message *pkcs7, const void **_data, size_t *_data_len, - bool want_wrapper) + size_t *_headerlen) { - size_t wrapper; - if (!pkcs7->data) return -ENODATA; - wrapper = want_wrapper ? pkcs7->data_hdrlen : 0; - *_data = pkcs7->data - wrapper; - *_data_len = pkcs7->data_len + wrapper; + *_data = pkcs7->data; + *_data_len = pkcs7->data_len; + if (_headerlen) + *_headerlen = pkcs7->data_hdrlen; return 0; } EXPORT_SYMBOL_GPL(pkcs7_get_content_data); diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c index 7e8c2338ae25..265351075b0e 100644 --- a/crypto/asymmetric_keys/verify_pefile.c +++ b/crypto/asymmetric_keys/verify_pefile.c @@ -16,7 +16,7 @@ #include #include #include -#include +#include #include #include "verify_pefile.h" @@ -392,9 +392,8 @@ error_no_desc: * verify_pefile_signature - Verify the signature on a PE binary image * @pebuf: Buffer containing the PE binary image * @pelen: Length of the binary image - * @trust_keyring: Signing certificates to use as starting points + * @trust_keys: Signing certificate(s) to use as starting points * @usage: The use to which the key is being put. - * @_trusted: Set to true if trustworth, false otherwise * * Validate that the certificate chain inside the PKCS#7 message inside the PE * binary image intersects keys we already know and trust. @@ -418,14 +417,10 @@ error_no_desc: * May also return -ENOMEM. */ int verify_pefile_signature(const void *pebuf, unsigned pelen, - struct key *trusted_keyring, - enum key_being_used_for usage, - bool *_trusted) + struct key *trusted_keys, + enum key_being_used_for usage) { - struct pkcs7_message *pkcs7; struct pefile_context ctx; - const void *data; - size_t datalen; int ret; kenter(""); @@ -439,19 +434,10 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen, if (ret < 0) return ret; - pkcs7 = pkcs7_parse_message(pebuf + ctx.sig_offset, ctx.sig_len); - if (IS_ERR(pkcs7)) - return PTR_ERR(pkcs7); - ctx.pkcs7 = pkcs7; - - ret = pkcs7_get_content_data(ctx.pkcs7, &data, &datalen, false); - if (ret < 0 || datalen == 0) { - pr_devel("PKCS#7 message does not contain data\n"); - ret = -EBADMSG; - goto error; - } - - ret = mscode_parse(&ctx); + ret = verify_pkcs7_signature(NULL, 0, + pebuf + ctx.sig_offset, ctx.sig_len, + trusted_keys, -EKEYREJECTED, usage, + mscode_parse, &ctx); if (ret < 0) goto error; @@ -462,16 +448,8 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen, * contents. */ ret = pefile_digest_pe(pebuf, pelen, &ctx); - if (ret < 0) - goto error; - - ret = pkcs7_verify(pkcs7, usage); - if (ret < 0) - goto error; - - ret = pkcs7_validate_trust(pkcs7, trusted_keyring, _trusted); error: - pkcs7_free_message(ctx.pkcs7); + kfree(ctx.digest); return ret; } diff --git a/crypto/asymmetric_keys/verify_pefile.h b/crypto/asymmetric_keys/verify_pefile.h index a133eb81a492..cd4d20930728 100644 --- a/crypto/asymmetric_keys/verify_pefile.h +++ b/crypto/asymmetric_keys/verify_pefile.h @@ -9,7 +9,6 @@ * 2 of the Licence, or (at your option) any later version. */ -#include #include #include @@ -23,7 +22,6 @@ struct pefile_context { unsigned sig_offset; unsigned sig_len; const struct section_header *secs; - struct pkcs7_message *pkcs7; /* PKCS#7 MS Individual Code Signing content */ const void *digest; /* Digest */ @@ -39,4 +37,5 @@ struct pefile_context { /* * mscode_parser.c */ -extern int mscode_parse(struct pefile_context *ctx); +extern int mscode_parse(void *_ctx, const void *content_data, size_t data_len, + size_t asn1hdrlen); diff --git a/include/crypto/pkcs7.h b/include/crypto/pkcs7.h index 441aff9b5aa7..8323e3e57131 100644 --- a/include/crypto/pkcs7.h +++ b/include/crypto/pkcs7.h @@ -12,6 +12,7 @@ #ifndef _CRYPTO_PKCS7_H #define _CRYPTO_PKCS7_H +#include #include struct key; @@ -26,7 +27,7 @@ extern void pkcs7_free_message(struct pkcs7_message *pkcs7); extern int pkcs7_get_content_data(const struct pkcs7_message *pkcs7, const void **_data, size_t *_datalen, - bool want_wrapper); + size_t *_headerlen); /* * pkcs7_trust.c diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 2f5de5c1a3a0..b3928e801b8c 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -14,20 +14,6 @@ #ifndef _LINUX_PUBLIC_KEY_H #define _LINUX_PUBLIC_KEY_H -/* - * The use to which an asymmetric key is being put. - */ -enum key_being_used_for { - VERIFYING_MODULE_SIGNATURE, - VERIFYING_FIRMWARE_SIGNATURE, - VERIFYING_KEXEC_PE_SIGNATURE, - VERIFYING_KEY_SIGNATURE, - VERIFYING_KEY_SELF_SIGNATURE, - VERIFYING_UNSPECIFIED_SIGNATURE, - NR__KEY_BEING_USED_FOR -}; -extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR]; - /* * Cryptographic data for the public-key subtype of the asymmetric key type. * diff --git a/include/keys/asymmetric-type.h b/include/keys/asymmetric-type.h index 70a8775bb444..d1e23dda4363 100644 --- a/include/keys/asymmetric-type.h +++ b/include/keys/asymmetric-type.h @@ -15,6 +15,7 @@ #define _KEYS_ASYMMETRIC_TYPE_H #include +#include extern struct key_type key_type_asymmetric; diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h index 39fd38cfa8c9..b2d645ac35a0 100644 --- a/include/keys/system_keyring.h +++ b/include/keys/system_keyring.h @@ -15,6 +15,7 @@ #ifdef CONFIG_SYSTEM_TRUSTED_KEYRING #include +#include #include extern struct key *system_trusted_keyring; @@ -29,12 +30,6 @@ static inline struct key *get_system_trusted_keyring(void) } #endif -#ifdef CONFIG_SYSTEM_DATA_VERIFICATION -extern int system_verify_data(const void *data, unsigned long len, - const void *raw_pkcs7, size_t pkcs7_len, - enum key_being_used_for usage); -#endif - #ifdef CONFIG_IMA_MOK_KEYRING extern struct key *ima_mok_keyring; extern struct key *ima_blacklist_keyring; diff --git a/include/linux/verification.h b/include/linux/verification.h new file mode 100644 index 000000000000..bb0fcf941cb7 --- /dev/null +++ b/include/linux/verification.h @@ -0,0 +1,50 @@ +/* Signature verification + * + * Copyright (C) 2014 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_VERIFICATION_H +#define _LINUX_VERIFICATION_H + +/* + * The use to which an asymmetric key is being put. + */ +enum key_being_used_for { + VERIFYING_MODULE_SIGNATURE, + VERIFYING_FIRMWARE_SIGNATURE, + VERIFYING_KEXEC_PE_SIGNATURE, + VERIFYING_KEY_SIGNATURE, + VERIFYING_KEY_SELF_SIGNATURE, + VERIFYING_UNSPECIFIED_SIGNATURE, + NR__KEY_BEING_USED_FOR +}; +extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR]; + +#ifdef CONFIG_SYSTEM_DATA_VERIFICATION + +struct key; + +extern int verify_pkcs7_signature(const void *data, size_t len, + const void *raw_pkcs7, size_t pkcs7_len, + struct key *trusted_keys, + int untrusted_error, + enum key_being_used_for usage, + int (*view_content)(void *ctx, + const void *data, size_t len, + size_t asn1hdrlen), + void *ctx); + +#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION +extern int verify_pefile_signature(const void *pebuf, unsigned pelen, + struct key *trusted_keys, + enum key_being_used_for usage); +#endif + +#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ +#endif /* _LINUX_VERIFY_PEFILE_H */ diff --git a/include/linux/verify_pefile.h b/include/linux/verify_pefile.h deleted file mode 100644 index da2049b5161c..000000000000 --- a/include/linux/verify_pefile.h +++ /dev/null @@ -1,22 +0,0 @@ -/* Signed PE file verification - * - * Copyright (C) 2014 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_VERIFY_PEFILE_H -#define _LINUX_VERIFY_PEFILE_H - -#include - -extern int verify_pefile_signature(const void *pebuf, unsigned pelen, - struct key *trusted_keyring, - enum key_being_used_for usage, - bool *_trusted); - -#endif /* _LINUX_VERIFY_PEFILE_H */ diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 64b9dead4a07..593aace88a02 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -80,6 +80,7 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen) return -EBADMSG; } - return system_verify_data(mod, modlen, mod + modlen, sig_len, - VERIFYING_MODULE_SIGNATURE); + return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, + NULL, -ENOKEY, VERIFYING_MODULE_SIGNATURE, + NULL, NULL); } -- cgit v1.3-14-g43fede From bda850cd214e90b1be0cc25bc48c4f6ac53eb543 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 6 Apr 2016 16:14:24 +0100 Subject: PKCS#7: Make trust determination dependent on contents of trust keyring Make the determination of the trustworthiness of a key dependent on whether a key that can verify it is present in the supplied ring of trusted keys rather than whether or not the verifying key has KEY_FLAG_TRUSTED set. verify_pkcs7_signature() will return -ENOKEY if the PKCS#7 message trust chain cannot be verified. Signed-off-by: David Howells --- certs/system_keyring.c | 13 ++++--------- crypto/asymmetric_keys/pkcs7_key_type.c | 2 +- crypto/asymmetric_keys/pkcs7_parser.h | 1 - crypto/asymmetric_keys/pkcs7_trust.c | 18 +++--------------- crypto/asymmetric_keys/verify_pefile.c | 2 +- crypto/asymmetric_keys/x509_parser.h | 1 - include/crypto/pkcs7.h | 3 +-- include/linux/verification.h | 1 - kernel/module_signing.c | 2 +- 9 files changed, 11 insertions(+), 32 deletions(-) (limited to 'include/crypto') diff --git a/certs/system_keyring.c b/certs/system_keyring.c index a83bffedc0aa..dc18869ff680 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -121,7 +121,6 @@ late_initcall(load_system_certificate_list); int verify_pkcs7_signature(const void *data, size_t len, const void *raw_pkcs7, size_t pkcs7_len, struct key *trusted_keys, - int untrusted_error, enum key_being_used_for usage, int (*view_content)(void *ctx, const void *data, size_t len, @@ -129,7 +128,6 @@ int verify_pkcs7_signature(const void *data, size_t len, void *ctx) { struct pkcs7_message *pkcs7; - bool trusted; int ret; pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len); @@ -149,13 +147,10 @@ int verify_pkcs7_signature(const void *data, size_t len, if (!trusted_keys) trusted_keys = system_trusted_keyring; - ret = pkcs7_validate_trust(pkcs7, trusted_keys, &trusted); - if (ret < 0) - goto error; - - if (!trusted && untrusted_error) { - pr_err("PKCS#7 signature not signed with a trusted key\n"); - ret = untrusted_error; + ret = pkcs7_validate_trust(pkcs7, trusted_keys); + if (ret < 0) { + if (ret == -ENOKEY) + pr_err("PKCS#7 signature not signed with a trusted key\n"); goto error; } diff --git a/crypto/asymmetric_keys/pkcs7_key_type.c b/crypto/asymmetric_keys/pkcs7_key_type.c index ab9bf5363ecd..3b92523882e5 100644 --- a/crypto/asymmetric_keys/pkcs7_key_type.c +++ b/crypto/asymmetric_keys/pkcs7_key_type.c @@ -62,7 +62,7 @@ static int pkcs7_preparse(struct key_preparsed_payload *prep) return verify_pkcs7_signature(NULL, 0, prep->data, prep->datalen, - NULL, -ENOKEY, usage, + NULL, usage, pkcs7_view_content, prep); } diff --git a/crypto/asymmetric_keys/pkcs7_parser.h b/crypto/asymmetric_keys/pkcs7_parser.h index d5eec31e95b6..f4e81074f5e0 100644 --- a/crypto/asymmetric_keys/pkcs7_parser.h +++ b/crypto/asymmetric_keys/pkcs7_parser.h @@ -22,7 +22,6 @@ struct pkcs7_signed_info { struct pkcs7_signed_info *next; struct x509_certificate *signer; /* Signing certificate (in msg->certs) */ unsigned index; - bool trusted; bool unsupported_crypto; /* T if not usable due to missing crypto */ /* Message digest - the digest of the Content Data (or NULL) */ diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c index b9a5487cd82d..36e77cb07bd0 100644 --- a/crypto/asymmetric_keys/pkcs7_trust.c +++ b/crypto/asymmetric_keys/pkcs7_trust.c @@ -30,7 +30,6 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7, struct public_key_signature *sig = sinfo->sig; struct x509_certificate *x509, *last = NULL, *p; struct key *key; - bool trusted; int ret; kenter(",%u,", sinfo->index); @@ -42,10 +41,8 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7, for (x509 = sinfo->signer; x509; x509 = x509->signer) { if (x509->seen) { - if (x509->verified) { - trusted = x509->trusted; + if (x509->verified) goto verified; - } kleave(" = -ENOKEY [cached]"); return -ENOKEY; } @@ -122,7 +119,6 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7, matched: ret = verify_signature(key, sig); - trusted = test_bit(KEY_FLAG_TRUSTED, &key->flags); key_put(key); if (ret < 0) { if (ret == -ENOMEM) @@ -134,12 +130,9 @@ matched: verified: if (x509) { x509->verified = true; - for (p = sinfo->signer; p != x509; p = p->signer) { + for (p = sinfo->signer; p != x509; p = p->signer) p->verified = true; - p->trusted = trusted; - } } - sinfo->trusted = trusted; kleave(" = 0"); return 0; } @@ -148,7 +141,6 @@ verified: * pkcs7_validate_trust - Validate PKCS#7 trust chain * @pkcs7: The PKCS#7 certificate to validate * @trust_keyring: Signing certificates to use as starting points - * @_trusted: Set to true if trustworth, false otherwise * * Validate that the certificate chain inside the PKCS#7 message intersects * keys we already know and trust. @@ -170,16 +162,13 @@ verified: * May also return -ENOMEM. */ int pkcs7_validate_trust(struct pkcs7_message *pkcs7, - struct key *trust_keyring, - bool *_trusted) + struct key *trust_keyring) { struct pkcs7_signed_info *sinfo; struct x509_certificate *p; int cached_ret = -ENOKEY; int ret; - *_trusted = false; - for (p = pkcs7->certs; p; p = p->next) p->seen = false; @@ -193,7 +182,6 @@ int pkcs7_validate_trust(struct pkcs7_message *pkcs7, cached_ret = -ENOPKG; continue; case 0: - *_trusted |= sinfo->trusted; cached_ret = 0; continue; default: diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c index 265351075b0e..672a94c2c3ff 100644 --- a/crypto/asymmetric_keys/verify_pefile.c +++ b/crypto/asymmetric_keys/verify_pefile.c @@ -436,7 +436,7 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen, ret = verify_pkcs7_signature(NULL, 0, pebuf + ctx.sig_offset, ctx.sig_len, - trusted_keys, -EKEYREJECTED, usage, + trusted_keys, usage, mscode_parse, &ctx); if (ret < 0) goto error; diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h index f24f4d808e7f..05eef1c68881 100644 --- a/crypto/asymmetric_keys/x509_parser.h +++ b/crypto/asymmetric_keys/x509_parser.h @@ -39,7 +39,6 @@ struct x509_certificate { unsigned index; bool seen; /* Infinite recursion prevention */ bool verified; - bool trusted; bool self_signed; /* T if self-signed (check unsupported_sig too) */ bool unsupported_key; /* T if key uses unsupported crypto */ bool unsupported_sig; /* T if signature uses unsupported crypto */ diff --git a/include/crypto/pkcs7.h b/include/crypto/pkcs7.h index 8323e3e57131..583f199400a3 100644 --- a/include/crypto/pkcs7.h +++ b/include/crypto/pkcs7.h @@ -33,8 +33,7 @@ extern int pkcs7_get_content_data(const struct pkcs7_message *pkcs7, * pkcs7_trust.c */ extern int pkcs7_validate_trust(struct pkcs7_message *pkcs7, - struct key *trust_keyring, - bool *_trusted); + struct key *trust_keyring); /* * pkcs7_verify.c diff --git a/include/linux/verification.h b/include/linux/verification.h index bb0fcf941cb7..a10549a6c7cd 100644 --- a/include/linux/verification.h +++ b/include/linux/verification.h @@ -33,7 +33,6 @@ struct key; extern int verify_pkcs7_signature(const void *data, size_t len, const void *raw_pkcs7, size_t pkcs7_len, struct key *trusted_keys, - int untrusted_error, enum key_being_used_for usage, int (*view_content)(void *ctx, const void *data, size_t len, diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 593aace88a02..6a64e03b9f44 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -81,6 +81,6 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen) } return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, - NULL, -ENOKEY, VERIFYING_MODULE_SIGNATURE, + NULL, VERIFYING_MODULE_SIGNATURE, NULL, NULL); } -- cgit v1.3-14-g43fede From 983023f28bff62b4462fd3575a86a8947ac592d8 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 6 Apr 2016 16:14:25 +0100 Subject: KEYS: Move x509_request_asymmetric_key() to asymmetric_type.c Move x509_request_asymmetric_key() to asymmetric_type.c so that it can be generalised. Signed-off-by: David Howells --- crypto/asymmetric_keys/asymmetric_type.c | 89 ++++++++++++++++++++++++++++++++ crypto/asymmetric_keys/x509_public_key.c | 89 -------------------------------- include/crypto/public_key.h | 6 --- include/keys/asymmetric-type.h | 5 ++ 4 files changed, 94 insertions(+), 95 deletions(-) (limited to 'include/crypto') diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index a79d30128821..c4d66cd82860 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -34,6 +34,95 @@ EXPORT_SYMBOL_GPL(key_being_used_for); static LIST_HEAD(asymmetric_key_parsers); static DECLARE_RWSEM(asymmetric_key_parsers_sem); +/** + * x509_request_asymmetric_key - Request a key by X.509 certificate params. + * @keyring: The keys to search. + * @id: The issuer & serialNumber to look for or NULL. + * @skid: The subjectKeyIdentifier to look for or NULL. + * @partial: Use partial match if true, exact if false. + * + * Find a key in the given keyring by identifier. The preferred identifier is + * the issuer + serialNumber and the fallback identifier is the + * subjectKeyIdentifier. If both are given, the lookup is by the former, but + * the latter must also match. + */ +struct key *x509_request_asymmetric_key(struct key *keyring, + const struct asymmetric_key_id *id, + const struct asymmetric_key_id *skid, + bool partial) +{ + struct key *key; + key_ref_t ref; + const char *lookup; + char *req, *p; + int len; + + if (id) { + lookup = id->data; + len = id->len; + } else { + lookup = skid->data; + len = skid->len; + } + + /* Construct an identifier "id:". */ + p = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL); + if (!req) + return ERR_PTR(-ENOMEM); + + if (partial) { + *p++ = 'i'; + *p++ = 'd'; + } else { + *p++ = 'e'; + *p++ = 'x'; + } + *p++ = ':'; + p = bin2hex(p, lookup, len); + *p = 0; + + pr_debug("Look up: \"%s\"\n", req); + + ref = keyring_search(make_key_ref(keyring, 1), + &key_type_asymmetric, req); + if (IS_ERR(ref)) + pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref)); + kfree(req); + + if (IS_ERR(ref)) { + switch (PTR_ERR(ref)) { + /* Hide some search errors */ + case -EACCES: + case -ENOTDIR: + case -EAGAIN: + return ERR_PTR(-ENOKEY); + default: + return ERR_CAST(ref); + } + } + + key = key_ref_to_ptr(ref); + if (id && skid) { + const struct asymmetric_key_ids *kids = asymmetric_key_ids(key); + if (!kids->id[1]) { + pr_debug("issuer+serial match, but expected SKID missing\n"); + goto reject; + } + if (!asymmetric_key_id_same(skid, kids->id[1])) { + pr_debug("issuer+serial match, but SKID does not\n"); + goto reject; + } + } + + pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key)); + return key; + +reject: + key_put(key); + return ERR_PTR(-EKEYREJECTED); +} +EXPORT_SYMBOL_GPL(x509_request_asymmetric_key); + /** * asymmetric_key_generate_id: Construct an asymmetric key ID * @val_1: First binary blob diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index fc77a2bd70ba..2fb594175cef 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -58,95 +58,6 @@ static int __init ca_keys_setup(char *str) __setup("ca_keys=", ca_keys_setup); #endif -/** - * x509_request_asymmetric_key - Request a key by X.509 certificate params. - * @keyring: The keys to search. - * @id: The issuer & serialNumber to look for or NULL. - * @skid: The subjectKeyIdentifier to look for or NULL. - * @partial: Use partial match if true, exact if false. - * - * Find a key in the given keyring by identifier. The preferred identifier is - * the issuer + serialNumber and the fallback identifier is the - * subjectKeyIdentifier. If both are given, the lookup is by the former, but - * the latter must also match. - */ -struct key *x509_request_asymmetric_key(struct key *keyring, - const struct asymmetric_key_id *id, - const struct asymmetric_key_id *skid, - bool partial) -{ - struct key *key; - key_ref_t ref; - const char *lookup; - char *req, *p; - int len; - - if (id) { - lookup = id->data; - len = id->len; - } else { - lookup = skid->data; - len = skid->len; - } - - /* Construct an identifier "id:". */ - p = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL); - if (!req) - return ERR_PTR(-ENOMEM); - - if (partial) { - *p++ = 'i'; - *p++ = 'd'; - } else { - *p++ = 'e'; - *p++ = 'x'; - } - *p++ = ':'; - p = bin2hex(p, lookup, len); - *p = 0; - - pr_debug("Look up: \"%s\"\n", req); - - ref = keyring_search(make_key_ref(keyring, 1), - &key_type_asymmetric, req); - if (IS_ERR(ref)) - pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref)); - kfree(req); - - if (IS_ERR(ref)) { - switch (PTR_ERR(ref)) { - /* Hide some search errors */ - case -EACCES: - case -ENOTDIR: - case -EAGAIN: - return ERR_PTR(-ENOKEY); - default: - return ERR_CAST(ref); - } - } - - key = key_ref_to_ptr(ref); - if (id && skid) { - const struct asymmetric_key_ids *kids = asymmetric_key_ids(key); - if (!kids->id[1]) { - pr_debug("issuer+serial match, but expected SKID missing\n"); - goto reject; - } - if (!asymmetric_key_id_same(skid, kids->id[1])) { - pr_debug("issuer+serial match, but SKID does not\n"); - goto reject; - } - } - - pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key)); - return key; - -reject: - key_put(key); - return ERR_PTR(-EKEYREJECTED); -} -EXPORT_SYMBOL_GPL(x509_request_asymmetric_key); - /* * Set up the signature parameters in an X.509 certificate. This involves * digesting the signed data and extracting the signature. diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index b3928e801b8c..96ef27b8dd41 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -50,12 +50,6 @@ struct key; extern int verify_signature(const struct key *key, const struct public_key_signature *sig); -struct asymmetric_key_id; -extern struct key *x509_request_asymmetric_key(struct key *keyring, - const struct asymmetric_key_id *id, - const struct asymmetric_key_id *skid, - bool partial); - int public_key_verify_signature(const struct public_key *pkey, const struct public_key_signature *sig); diff --git a/include/keys/asymmetric-type.h b/include/keys/asymmetric-type.h index d1e23dda4363..735db697c4d2 100644 --- a/include/keys/asymmetric-type.h +++ b/include/keys/asymmetric-type.h @@ -76,6 +76,11 @@ const struct asymmetric_key_ids *asymmetric_key_ids(const struct key *key) return key->payload.data[asym_key_ids]; } +extern struct key *x509_request_asymmetric_key(struct key *keyring, + const struct asymmetric_key_id *id, + const struct asymmetric_key_id *skid, + bool partial); + /* * The payload is at the discretion of the subtype. */ -- cgit v1.3-14-g43fede From a511e1af8b12f44c6e55786c463c9f093c214fb6 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 6 Apr 2016 16:14:26 +0100 Subject: KEYS: Move the point of trust determination to __key_link() Move the point at which a key is determined to be trustworthy to __key_link() so that we use the contents of the keyring being linked in to to determine whether the key being linked in is trusted or not. What is 'trusted' then becomes a matter of what's in the keyring. Currently, the test is done when the key is parsed, but given that at that point we can only sensibly refer to the contents of the system trusted keyring, we can only use that as the basis for working out the trustworthiness of a new key. With this change, a trusted keyring is a set of keys that once the trusted-only flag is set cannot be added to except by verification through one of the contained keys. Further, adding a key into a trusted keyring, whilst it might grant trustworthiness in the context of that keyring, does not automatically grant trustworthiness in the context of a second keyring to which it could be secondarily linked. To accomplish this, the authentication data associated with the key source must now be retained. For an X.509 cert, this means the contents of the AuthorityKeyIdentifier and the signature data. If system keyrings are disabled then restrict_link_by_builtin_trusted() resolves to restrict_link_reject(). The integrity digital signature code still works correctly with this as it was previously using KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there is no system keyring against which trust can be determined. Signed-off-by: David Howells --- certs/system_keyring.c | 20 +++++++++-- crypto/asymmetric_keys/restrict.c | 62 ++++++++++++++++---------------- crypto/asymmetric_keys/x509_parser.h | 6 ---- crypto/asymmetric_keys/x509_public_key.c | 21 +---------- include/crypto/public_key.h | 7 ++++ include/keys/system_keyring.h | 19 ++++------ kernel/module_signing.c | 2 +- security/integrity/digsig.c | 33 ++++++++++++++++- security/integrity/ima/ima_mok.c | 6 ++-- 9 files changed, 100 insertions(+), 76 deletions(-) (limited to 'include/crypto') diff --git a/certs/system_keyring.c b/certs/system_keyring.c index 417d65882870..4e2fa8ab01d6 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -18,12 +18,26 @@ #include #include -struct key *system_trusted_keyring; -EXPORT_SYMBOL_GPL(system_trusted_keyring); +static struct key *system_trusted_keyring; extern __initconst const u8 system_certificate_list[]; extern __initconst const unsigned long system_certificate_list_size; +/** + * restrict_link_by_builtin_trusted - Restrict keyring addition by system CA + * + * Restrict the addition of keys into a keyring based on the key-to-be-added + * being vouched for by a key in the system keyring. + */ +int restrict_link_by_builtin_trusted(struct key *keyring, + const struct key_type *type, + unsigned long flags, + const union key_payload *payload) +{ + return restrict_link_by_signature(system_trusted_keyring, + type, payload); +} + /* * Load the compiled-in keys */ @@ -37,7 +51,7 @@ static __init int system_trusted_keyring_init(void) ((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH), KEY_ALLOC_NOT_IN_QUOTA, - keyring_restrict_trusted_only, NULL); + restrict_link_by_builtin_trusted, NULL); if (IS_ERR(system_trusted_keyring)) panic("Can't allocate system trusted keyring\n"); return 0; diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c index b4c10f2f5034..ac4bddf669de 100644 --- a/crypto/asymmetric_keys/restrict.c +++ b/crypto/asymmetric_keys/restrict.c @@ -1,6 +1,6 @@ /* Instantiate a public key crypto key from an X.509 Certificate * - * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2012, 2016 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -9,20 +9,12 @@ * 2 of the Licence, or (at your option) any later version. */ -#define pr_fmt(fmt) "X.509: "fmt +#define pr_fmt(fmt) "ASYM: "fmt #include #include -#include #include -#include -#include -#include -#include -#include -#include #include #include "asymmetric_keys.h" -#include "x509_parser.h" static bool use_builtin_keys; static struct asymmetric_key_id *ca_keyid; @@ -62,45 +54,55 @@ static int __init ca_keys_setup(char *str) __setup("ca_keys=", ca_keys_setup); #endif -/* +/** + * restrict_link_by_signature - Restrict additions to a ring of public keys + * @trust_keyring: A ring of keys that can be used to vouch for the new cert. + * @type: The type of key being added. + * @payload: The payload of the new key. + * * Check the new certificate against the ones in the trust keyring. If one of * those is the signing key and validates the new certificate, then mark the * new certificate as being trusted. * - * Return 0 if the new certificate was successfully validated, 1 if we couldn't - * find a matching parent certificate in the trusted list and an error if there - * is a matching certificate but the signature check fails. + * Returns 0 if the new certificate was accepted, -ENOKEY if we couldn't find a + * matching parent certificate in the trusted list, -EKEYREJECTED if the + * signature check fails or the key is blacklisted and some other error if + * there is a matching certificate but the signature check cannot be performed. */ -int x509_validate_trust(struct x509_certificate *cert, - struct key *trust_keyring) +int restrict_link_by_signature(struct key *trust_keyring, + const struct key_type *type, + const union key_payload *payload) { - struct public_key_signature *sig = cert->sig; + const struct public_key_signature *sig; struct key *key; - int ret = 1; + int ret; - if (!sig->auth_ids[0] && !sig->auth_ids[1]) - return 1; + pr_devel("==>%s()\n", __func__); if (!trust_keyring) + return -ENOKEY; + + if (type != &key_type_asymmetric) return -EOPNOTSUPP; + + sig = payload->data[asym_auth]; + if (!sig->auth_ids[0] && !sig->auth_ids[1]) + return 0; + if (ca_keyid && !asymmetric_key_id_partial(sig->auth_ids[1], ca_keyid)) return -EPERM; - if (cert->unsupported_sig) - return -ENOPKG; + /* See if we have a key that signed this one. */ key = find_asymmetric_key(trust_keyring, sig->auth_ids[0], sig->auth_ids[1], false); if (IS_ERR(key)) - return PTR_ERR(key); + return -ENOKEY; - if (!use_builtin_keys || - test_bit(KEY_FLAG_BUILTIN, &key->flags)) { - ret = verify_signature(key, cert->sig); - if (ret == -ENOPKG) - cert->unsupported_sig = true; - } + if (use_builtin_keys && !test_bit(KEY_FLAG_BUILTIN, &key->flags)) + ret = -ENOKEY; + else + ret = verify_signature(key, sig); key_put(key); return ret; } -EXPORT_SYMBOL_GPL(x509_validate_trust); diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h index 7a802b09a509..05eef1c68881 100644 --- a/crypto/asymmetric_keys/x509_parser.h +++ b/crypto/asymmetric_keys/x509_parser.h @@ -58,9 +58,3 @@ extern int x509_decode_time(time64_t *_t, size_t hdrlen, */ extern int x509_get_sig_params(struct x509_certificate *cert); extern int x509_check_for_self_signed(struct x509_certificate *cert); - -/* - * public_key_trust.c - */ -extern int x509_validate_trust(struct x509_certificate *cert, - struct key *trust_keyring); diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index 6d7f42f0de9a..fb732296cd36 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -178,31 +178,12 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) cert->pub->id_type = "X509"; - /* See if we can derive the trustability of this certificate. - * - * When it comes to self-signed certificates, we cannot evaluate - * trustedness except by the fact that we obtained it from a trusted - * location. So we just rely on x509_validate_trust() failing in this - * case. - * - * Note that there's a possibility of a self-signed cert matching a - * cert that we have (most likely a duplicate that we already trust) - - * in which case it will be marked trusted. - */ - if (cert->unsupported_sig || cert->self_signed) { + if (cert->unsupported_sig) { public_key_signature_free(cert->sig); cert->sig = NULL; } else { pr_devel("Cert Signature: %s + %s\n", cert->sig->pkey_algo, cert->sig->hash_algo); - - ret = x509_validate_trust(cert, get_system_trusted_keyring()); - if (ret) - ret = x509_validate_trust(cert, get_ima_mok_keyring()); - if (ret == -EKEYREJECTED) - goto error_free_cert; - if (!ret) - prep->trusted = true; } /* Propose a description */ diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 96ef27b8dd41..882ca0e1e7a5 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -47,6 +47,13 @@ extern void public_key_signature_free(struct public_key_signature *sig); extern struct asymmetric_key_subtype public_key_subtype; struct key; +struct key_type; +union key_payload; + +extern int restrict_link_by_signature(struct key *trust_keyring, + const struct key_type *type, + const union key_payload *payload); + extern int verify_signature(const struct key *key, const struct public_key_signature *sig); diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h index b2d645ac35a0..93715913a0b1 100644 --- a/include/keys/system_keyring.h +++ b/include/keys/system_keyring.h @@ -12,22 +12,17 @@ #ifndef _KEYS_SYSTEM_KEYRING_H #define _KEYS_SYSTEM_KEYRING_H +#include + #ifdef CONFIG_SYSTEM_TRUSTED_KEYRING -#include -#include -#include +extern int restrict_link_by_builtin_trusted(struct key *keyring, + const struct key_type *type, + unsigned long flags, + const union key_payload *payload); -extern struct key *system_trusted_keyring; -static inline struct key *get_system_trusted_keyring(void) -{ - return system_trusted_keyring; -} #else -static inline struct key *get_system_trusted_keyring(void) -{ - return NULL; -} +#define restrict_link_by_builtin_trusted restrict_link_reject #endif #ifdef CONFIG_IMA_MOK_KEYRING diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 6a64e03b9f44..937c844bee4a 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -12,7 +12,7 @@ #include #include #include -#include +#include #include #include "module-internal.h" diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 659566c2200b..d647178c6bbd 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include #include "integrity.h" @@ -40,6 +42,35 @@ static bool init_keyring __initdata = true; static bool init_keyring __initdata; #endif +#ifdef CONFIG_SYSTEM_TRUSTED_KEYRING +/* + * Restrict the addition of keys into the IMA keyring. + * + * Any key that needs to go in .ima keyring must be signed by CA in + * either .system or .ima_mok keyrings. + */ +static int restrict_link_by_ima_mok(struct key *keyring, + const struct key_type *type, + unsigned long flags, + const union key_payload *payload) +{ + int ret; + + ret = restrict_link_by_builtin_trusted(keyring, type, flags, payload); + if (ret != -ENOKEY) + return ret; + + return restrict_link_by_signature(get_ima_mok_keyring(), + type, payload); +} +#else +/* + * If there's no system trusted keyring, then keys cannot be loaded into + * .ima_mok and added keys cannot be marked trusted. + */ +#define restrict_link_by_ima_mok restrict_link_reject +#endif + int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, const char *digest, int digestlen) { @@ -84,7 +115,7 @@ int __init integrity_init_keyring(const unsigned int id) KEY_USR_VIEW | KEY_USR_READ | KEY_USR_WRITE | KEY_USR_SEARCH), KEY_ALLOC_NOT_IN_QUOTA, - NULL, NULL); + restrict_link_by_ima_mok, NULL); if (IS_ERR(keyring[id])) { err = PTR_ERR(keyring[id]); pr_info("Can't allocate %s keyring (%d)\n", diff --git a/security/integrity/ima/ima_mok.c b/security/integrity/ima/ima_mok.c index ef91248cb934..2988726d30d6 100644 --- a/security/integrity/ima/ima_mok.c +++ b/security/integrity/ima/ima_mok.c @@ -17,7 +17,7 @@ #include #include #include -#include +#include struct key *ima_mok_keyring; @@ -36,7 +36,7 @@ __init int ima_mok_init(void) KEY_USR_VIEW | KEY_USR_READ | KEY_USR_WRITE | KEY_USR_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, - keyring_restrict_trusted_only, NULL); + restrict_link_by_builtin_trusted, NULL); ima_blacklist_keyring = keyring_alloc(".ima_blacklist", KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), @@ -44,7 +44,7 @@ __init int ima_mok_init(void) KEY_USR_VIEW | KEY_USR_READ | KEY_USR_WRITE | KEY_USR_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, - keyring_restrict_trusted_only, NULL); + restrict_link_by_builtin_trusted, NULL); if (IS_ERR(ima_mok_keyring) || IS_ERR(ima_blacklist_keyring)) panic("Can't allocate IMA MOK or blacklist keyrings."); -- cgit v1.3-14-g43fede