diff options
56 files changed, 1341 insertions, 717 deletions
diff --git a/Documentation/security/keys.txt b/Documentation/security/keys.txt index 8c183873b2b7..20d05719bceb 100644 --- a/Documentation/security/keys.txt +++ b/Documentation/security/keys.txt @@ -823,6 +823,36 @@ The keyctl syscall functions are: A process must have search permission on the key for this function to be successful. + (*) Compute a Diffie-Hellman shared secret or public key + + long keyctl(KEYCTL_DH_COMPUTE, struct keyctl_dh_params *params, + char *buffer, size_t buflen); + + The params struct contains serial numbers for three keys: + + - The prime, p, known to both parties + - The local private key + - The base integer, which is either a shared generator or the + remote public key + + The value computed is: + + result = base ^ private (mod prime) + + If the base is the shared generator, the result is the local + public key. If the base is the remote public key, the result is + the shared secret. + + The buffer length must be at least the length of the prime, or zero. + + If the buffer length is nonzero, the length of the result is + returned when it is successfully calculated and copied in to the + buffer. When the buffer length is zero, the minimum required + buffer length is returned. + + This function will return error EOPNOTSUPP if the key type is not + supported, error ENOKEY if the key could not be found, or error + EACCES if the key is not readable by the caller. =============== KERNEL SERVICES @@ -999,6 +1029,10 @@ payload contents" for more information. struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, const struct cred *cred, key_perm_t perm, + int (*restrict_link)(struct key *, + const struct key_type *, + unsigned long, + const union key_payload *), unsigned long flags, struct key *dest); @@ -1010,6 +1044,24 @@ payload contents" for more information. KEY_ALLOC_NOT_IN_QUOTA in flags if the keyring shouldn't be accounted towards the user's quota). Error ENOMEM can also be returned. + If restrict_link not NULL, it should point to a function that will be + called each time an attempt is made to link a key into the new keyring. + This function is called to check whether a key may be added into the keying + or not. Callers of key_create_or_update() within the kernel can pass + KEY_ALLOC_BYPASS_RESTRICTION to suppress the check. An example of using + this is to manage rings of cryptographic keys that are set up when the + kernel boots where userspace is also permitted to add keys - provided they + can be verified by a key the kernel already has. + + When called, the restriction function will be passed the keyring being + added to, the key flags value and the type and payload of the key being + added. Note that when a new key is being created, this is called between + payload preparsing and actual key creation. The function should return 0 + to allow the link or an error to reject it. + + A convenience function, restrict_link_reject, exists to always return + -EPERM to in this case. + (*) To check the validity of a key, this function can be called: 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 <linux/kernel.h> #include <linux/mm.h> #include <linux/efi.h> -#include <linux/verify_pefile.h> -#include <keys/system_keyring.h> +#include <linux/verification.h> #include <asm/bootparam.h> #include <asm/setup.h> @@ -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/Kconfig b/certs/Kconfig index f0f8a4433685..fc5955f5fc8a 100644 --- a/certs/Kconfig +++ b/certs/Kconfig @@ -17,6 +17,7 @@ config MODULE_SIG_KEY config SYSTEM_TRUSTED_KEYRING bool "Provide system-wide ring of trusted keys" depends on KEYS + depends on ASYMMETRIC_KEY_TYPE help Provide a system keyring to which trusted keys can be added. Keys in the keyring are considered to be trusted. Keys may be added at will @@ -55,4 +56,12 @@ config SYSTEM_EXTRA_CERTIFICATE_SIZE This is the number of bytes reserved in the kernel image for a certificate to be inserted. +config SECONDARY_TRUSTED_KEYRING + bool "Provide a keyring to which extra trustable keys may be added" + depends on SYSTEM_TRUSTED_KEYRING + help + If set, provide a keyring to which extra keys may be added, provided + those keys are not blacklisted and are vouched for by a key built + into the kernel or already in the secondary trusted keyring. + endmenu diff --git a/certs/system_keyring.c b/certs/system_keyring.c index f4180326c2e1..50979d6dcecd 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -18,29 +18,88 @@ #include <keys/system_keyring.h> #include <crypto/pkcs7.h> -struct key *system_trusted_keyring; -EXPORT_SYMBOL_GPL(system_trusted_keyring); +static struct key *builtin_trusted_keys; +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING +static struct key *secondary_trusted_keys; +#endif extern __initconst const u8 system_certificate_list[]; extern __initconst const unsigned long system_certificate_list_size; +/** + * restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA + * + * Restrict the addition of keys into a keyring based on the key-to-be-added + * being vouched for by a key in the built in system keyring. + */ +int restrict_link_by_builtin_trusted(struct key *keyring, + const struct key_type *type, + const union key_payload *payload) +{ + return restrict_link_by_signature(builtin_trusted_keys, type, payload); +} + +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING +/** + * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring + * addition by both builtin and secondary keyrings + * + * Restrict the addition of keys into a keyring based on the key-to-be-added + * being vouched for by a key in either the built-in or the secondary system + * keyrings. + */ +int restrict_link_by_builtin_and_secondary_trusted( + struct key *keyring, + const struct key_type *type, + const union key_payload *payload) +{ + /* If we have a secondary trusted keyring, then that contains a link + * through to the builtin keyring and the search will follow that link. + */ + if (type == &key_type_keyring && + keyring == secondary_trusted_keys && + payload == &builtin_trusted_keys->payload) + /* Allow the builtin keyring to be added to the secondary */ + return 0; + + return restrict_link_by_signature(secondary_trusted_keys, type, payload); +} +#endif + /* - * Load the compiled-in keys + * Create the trusted keyrings */ static __init int system_trusted_keyring_init(void) { - pr_notice("Initialise system trusted keyring\n"); + pr_notice("Initialise system trusted keyrings\n"); - system_trusted_keyring = - keyring_alloc(".system_keyring", + builtin_trusted_keys = + keyring_alloc(".builtin_trusted_keys", 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); - if (IS_ERR(system_trusted_keyring)) - panic("Can't allocate system trusted keyring\n"); + KEY_ALLOC_NOT_IN_QUOTA, + NULL, NULL); + if (IS_ERR(builtin_trusted_keys)) + panic("Can't allocate builtin trusted keyring\n"); + +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING + secondary_trusted_keys = + keyring_alloc(".secondary_trusted_keys", + KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH | + KEY_USR_WRITE), + KEY_ALLOC_NOT_IN_QUOTA, + restrict_link_by_builtin_and_secondary_trusted, + NULL); + if (IS_ERR(secondary_trusted_keys)) + panic("Can't allocate secondary trusted keyring\n"); + + if (key_link(secondary_trusted_keys, builtin_trusted_keys) < 0) + panic("Can't link trusted keyrings\n"); +#endif - set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags); return 0; } @@ -76,7 +135,7 @@ static __init int load_system_certificate_list(void) if (plen > end - p) goto dodgy_cert; - key = key_create_or_update(make_key_ref(system_trusted_keyring, 1), + key = key_create_or_update(make_key_ref(builtin_trusted_keys, 1), "asymmetric", NULL, p, @@ -84,8 +143,8 @@ 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_BUILT_IN); + 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)); @@ -108,19 +167,27 @@ 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 builtin trusted keys only, + * (void *)1UL for all trusted keys). * @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, + 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; int ret; pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len); @@ -128,7 +195,7 @@ 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 +205,33 @@ 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 (ret < 0) + if (!trusted_keys) { + trusted_keys = builtin_trusted_keys; + } else if (trusted_keys == (void *)1UL) { +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING + trusted_keys = secondary_trusted_keys; +#else + trusted_keys = builtin_trusted_keys; +#endif + } + 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; + } + + 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; + } - if (!trusted) { - pr_err("PKCS#7 signature not signed with a trusted key\n"); - ret = -ENOKEY; + ret = view_content(ctx, data, len, asn1hdrlen); } error: @@ -152,6 +239,6 @@ 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..e28e912000a7 100644 --- a/crypto/asymmetric_keys/Kconfig +++ b/crypto/asymmetric_keys/Kconfig @@ -1,5 +1,5 @@ menuconfig ASYMMETRIC_KEY_TYPE - tristate "Asymmetric (public-key cryptographic) key type" + bool "Asymmetric (public-key cryptographic) key type" depends on KEYS help This option provides support for a key type that holds the data for @@ -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/Makefile b/crypto/asymmetric_keys/Makefile index f90486256f01..6516855bec18 100644 --- a/crypto/asymmetric_keys/Makefile +++ b/crypto/asymmetric_keys/Makefile @@ -4,7 +4,10 @@ obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o -asymmetric_keys-y := asymmetric_type.o signature.o +asymmetric_keys-y := \ + asymmetric_type.o \ + restrict.o \ + signature.o obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h index 1d450b580245..ca8e9ac34ce6 100644 --- a/crypto/asymmetric_keys/asymmetric_keys.h +++ b/crypto/asymmetric_keys/asymmetric_keys.h @@ -9,6 +9,8 @@ * 2 of the Licence, or (at your option) any later version. */ +#include <keys/asymmetric-type.h> + extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id); extern int __asymmetric_key_hex_to_key_id(const char *id, diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index 9f2165b27d52..6600181d5d01 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -35,6 +35,95 @@ static LIST_HEAD(asymmetric_key_parsers); static DECLARE_RWSEM(asymmetric_key_parsers_sem); /** + * find_asymmetric_key - Find a key by ID. + * @keyring: The keys to search. + * @id_0: The first ID to look for or NULL. + * @id_1: The second ID 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 id_0 and the fallback identifier is the id_1. If both are given, the + * lookup is by the former, but the latter must also match. + */ +struct key *find_asymmetric_key(struct key *keyring, + const struct asymmetric_key_id *id_0, + const struct asymmetric_key_id *id_1, + bool partial) +{ + struct key *key; + key_ref_t ref; + const char *lookup; + char *req, *p; + int len; + + if (id_0) { + lookup = id_0->data; + len = id_0->len; + } else { + lookup = id_1->data; + len = id_1->len; + } + + /* Construct an identifier "id:<keyid>". */ + 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_0 && id_1) { + const struct asymmetric_key_ids *kids = asymmetric_key_ids(key); + + if (!kids->id[0]) { + pr_debug("First ID matches, but second is missing\n"); + goto reject; + } + if (!asymmetric_key_id_same(id_1, kids->id[1])) { + pr_debug("First ID matches, but second 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(find_asymmetric_key); + +/** * asymmetric_key_generate_id: Construct an asymmetric key ID * @val_1: First binary blob * @len_1: Length of first binary blob @@ -331,7 +420,8 @@ static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep) pr_devel("==>%s()\n", __func__); if (subtype) { - subtype->destroy(prep->payload.data[asym_crypto]); + subtype->destroy(prep->payload.data[asym_crypto], + prep->payload.data[asym_auth]); module_put(subtype->owner); } asymmetric_key_free_kids(kids); @@ -346,13 +436,15 @@ static void asymmetric_key_destroy(struct key *key) struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key); struct asymmetric_key_ids *kids = key->payload.data[asym_key_ids]; void *data = key->payload.data[asym_crypto]; + void *auth = key->payload.data[asym_auth]; key->payload.data[asym_crypto] = NULL; key->payload.data[asym_subtype] = NULL; key->payload.data[asym_key_ids] = NULL; + key->payload.data[asym_auth] = NULL; if (subtype) { - subtype->destroy(data); + subtype->destroy(data, auth); module_put(subtype->owner); } 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..3b92523882e5 100644 --- a/crypto/asymmetric_keys/pkcs7_key_type.c +++ b/crypto/asymmetric_keys/pkcs7_key_type.c @@ -13,12 +13,9 @@ #include <linux/key.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/verification.h> #include <linux/key-type.h> -#include <keys/asymmetric-type.h> -#include <crypto/pkcs7.h> #include <keys/user-type.h> -#include <keys/system_keyring.h> -#include "pkcs7_parser.h" MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("PKCS#7 testing key type"); @@ -29,60 +26,47 @@ 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 *p |