diff options
Diffstat (limited to 'certs')
| -rw-r--r-- | certs/Kconfig | 16 | ||||
| -rw-r--r-- | certs/Makefile | 8 | ||||
| -rw-r--r-- | certs/system_certificates.S | 13 | ||||
| -rw-r--r-- | certs/system_keyring.c | 55 |
4 files changed, 77 insertions, 15 deletions
diff --git a/certs/Kconfig b/certs/Kconfig index b030b9c7ed34..f0f8a4433685 100644 --- a/certs/Kconfig +++ b/certs/Kconfig @@ -39,4 +39,20 @@ config SYSTEM_TRUSTED_KEYS form of DER-encoded *.x509 files in the top-level build directory, those are no longer used. You will need to set this option instead. +config SYSTEM_EXTRA_CERTIFICATE + bool "Reserve area for inserting a certificate without recompiling" + depends on SYSTEM_TRUSTED_KEYRING + help + If set, space for an extra certificate will be reserved in the kernel + image. This allows introducing a trusted certificate to the default + system keyring without recompiling the kernel. + +config SYSTEM_EXTRA_CERTIFICATE_SIZE + int "Number of bytes to reserve for the extra certificate" + depends on SYSTEM_EXTRA_CERTIFICATE + default 4096 + help + This is the number of bytes reserved in the kernel image for a + certificate to be inserted. + endmenu diff --git a/certs/Makefile b/certs/Makefile index 2773c4afa24c..4417cc5cf5e8 100644 --- a/certs/Makefile +++ b/certs/Makefile @@ -39,11 +39,19 @@ endif redirect_openssl = 2>&1 quiet_redirect_openssl = 2>&1 silent_redirect_openssl = 2>/dev/null +openssl_available = $(shell openssl help 2>/dev/null && echo yes) # We do it this way rather than having a boolean option for enabling an # external private key, because 'make randconfig' might enable such a # boolean option and we unfortunately can't make it depend on !RANDCONFIG. ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem") + +ifeq ($(openssl_available),yes) +X509TEXT=$(shell openssl x509 -in "certs/signing_key.pem" -text 2>/dev/null) + +$(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem")) +endif + $(obj)/signing_key.pem: $(obj)/x509.genkey @$(kecho) "###" @$(kecho) "### Now generating an X.509 key pair to be used for signing modules." diff --git a/certs/system_certificates.S b/certs/system_certificates.S index 9216e8c81764..c9ceb71a43fe 100644 --- a/certs/system_certificates.S +++ b/certs/system_certificates.S @@ -13,6 +13,19 @@ __cert_list_start: .incbin "certs/x509_certificate_list" __cert_list_end: +#ifdef CONFIG_SYSTEM_EXTRA_CERTIFICATE + .globl VMLINUX_SYMBOL(system_extra_cert) + .size system_extra_cert, CONFIG_SYSTEM_EXTRA_CERTIFICATE_SIZE +VMLINUX_SYMBOL(system_extra_cert): + .fill CONFIG_SYSTEM_EXTRA_CERTIFICATE_SIZE, 1, 0 + + .align 4 + .globl VMLINUX_SYMBOL(system_extra_cert_used) +VMLINUX_SYMBOL(system_extra_cert_used): + .int 0 + +#endif /* CONFIG_SYSTEM_EXTRA_CERTIFICATE */ + .align 8 .globl VMLINUX_SYMBOL(system_certificate_list_size) VMLINUX_SYMBOL(system_certificate_list_size): diff --git a/certs/system_keyring.c b/certs/system_keyring.c index 2570598b784d..a7bc8a18ed45 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -36,11 +36,10 @@ static __init int system_trusted_keyring_init(void) KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), ((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH), - KEY_ALLOC_NOT_IN_QUOTA, NULL); + KEY_ALLOC_NOT_IN_QUOTA, + keyring_restrict_trusted_only, NULL); if (IS_ERR(system_trusted_keyring)) panic("Can't allocate system trusted keyring\n"); - - set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags); return 0; } @@ -84,12 +83,13 @@ static __init int load_system_certificate_list(void) ((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ), KEY_ALLOC_NOT_IN_QUOTA | - KEY_ALLOC_TRUSTED); + KEY_ALLOC_TRUSTED | + KEY_ALLOC_BUILT_IN | + KEY_ALLOC_BYPASS_RESTRICTION); if (IS_ERR(key)) { pr_err("Problem loading in-kernel X.509 certificate (%ld)\n", PTR_ERR(key)); } else { - set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags); pr_notice("Loaded X.509 cert '%s'\n", key_ref_to_ptr(key)->description); key_ref_put(key); @@ -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 */ |