X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/c18c124eaa464aaaa5549e99e5a70fc9cbb50944..a39ff7e25e19b3a8c3020042a3872ca9ec9659f1:/bsd/kern/ubc_subr.c?ds=sidebyside diff --git a/bsd/kern/ubc_subr.c b/bsd/kern/ubc_subr.c index 83785b788..e05d13c3e 100644 --- a/bsd/kern/ubc_subr.c +++ b/bsd/kern/ubc_subr.c @@ -65,10 +65,12 @@ #include #include #include +#include #include #include /* last */ #include +#include #include #include @@ -109,6 +111,9 @@ static int ubc_umcallback(vnode_t, void *); static int ubc_msync_internal(vnode_t, off_t, off_t, off_t *, int, int *); static void ubc_cs_free(struct ubc_info *uip); +static boolean_t ubc_cs_supports_multilevel_hash(struct cs_blob *blob); +static void ubc_cs_convert_to_multilevel_hash(struct cs_blob *blob); + struct zone *ubc_info_zone; static uint32_t cs_blob_generation_count = 1; @@ -120,9 +125,6 @@ static uint32_t cs_blob_generation_count = 1; extern int cs_debug; #define PAGE_SHIFT_4K (12) -#define PAGE_SIZE_4K ((1<magic) == CSMAGIC_EMBEDDED_SIGNATURE) { - const CS_BlobIndex *limit; - const CS_BlobIndex *p; + return cs_hash->cs_type; +} - limit = &embedded->index[ntohl(embedded->count)]; - if (!cs_valid_range(&embedded->index[0], limit, - lower_bound, upper_bound)) { - return NULL; - } - for (p = embedded->index; p < limit; ++p) { - if (ntohl(p->type) == CSSLOT_CODEDIRECTORY) { - const unsigned char *base; +static const struct cs_hash cs_hash_sha1 = { + .cs_type = CS_HASHTYPE_SHA1, + .cs_size = CS_SHA1_LEN, + .cs_digest_size = SHA_DIGEST_LENGTH, + .cs_init = (cs_md_init)SHA1Init, + .cs_update = (cs_md_update)SHA1Update, + .cs_final = (cs_md_final)SHA1Final, +}; +#if CRYPTO_SHA2 +static const struct cs_hash cs_hash_sha256 = { + .cs_type = CS_HASHTYPE_SHA256, + .cs_size = SHA256_DIGEST_LENGTH, + .cs_digest_size = SHA256_DIGEST_LENGTH, + .cs_init = (cs_md_init)SHA256_Init, + .cs_update = (cs_md_update)SHA256_Update, + .cs_final = (cs_md_final)SHA256_Final, +}; +static const struct cs_hash cs_hash_sha256_truncate = { + .cs_type = CS_HASHTYPE_SHA256_TRUNCATED, + .cs_size = CS_SHA256_TRUNCATED_LEN, + .cs_digest_size = SHA256_DIGEST_LENGTH, + .cs_init = (cs_md_init)SHA256_Init, + .cs_update = (cs_md_update)SHA256_Update, + .cs_final = (cs_md_final)SHA256_Final, +}; +static const struct cs_hash cs_hash_sha384 = { + .cs_type = CS_HASHTYPE_SHA384, + .cs_size = SHA384_DIGEST_LENGTH, + .cs_digest_size = SHA384_DIGEST_LENGTH, + .cs_init = (cs_md_init)SHA384_Init, + .cs_update = (cs_md_update)SHA384_Update, + .cs_final = (cs_md_final)SHA384_Final, +}; +#endif - base = (const unsigned char *)embedded; - cd = (const CS_CodeDirectory *)(base + ntohl(p->offset)); - break; - } - } - } else { - /* - * Detached signatures come as a bare CS_CodeDirectory, - * without a blob. - */ - cd = (const CS_CodeDirectory *) embedded; +static struct cs_hash const * +cs_find_md(uint8_t type) +{ + if (type == CS_HASHTYPE_SHA1) { + return &cs_hash_sha1; +#if CRYPTO_SHA2 + } else if (type == CS_HASHTYPE_SHA256) { + return &cs_hash_sha256; + } else if (type == CS_HASHTYPE_SHA256_TRUNCATED) { + return &cs_hash_sha256_truncate; + } else if (type == CS_HASHTYPE_SHA384) { + return &cs_hash_sha384; +#endif } + return NULL; +} - if (cd && - cs_valid_range(cd, cd + 1, lower_bound, upper_bound) && - cs_valid_range(cd, (const char *) cd + ntohl(cd->length), - lower_bound, upper_bound) && - cs_valid_range(cd, (const char *) cd + ntohl(cd->hashOffset), - lower_bound, upper_bound) && - cs_valid_range(cd, (const char *) cd + - ntohl(cd->hashOffset) + - (ntohl(cd->nCodeSlots) * SHA1_RESULTLEN), - lower_bound, upper_bound) && - - ntohl(cd->magic) == CSMAGIC_CODEDIRECTORY) { - return cd; - } +union cs_hash_union { + SHA1_CTX sha1ctxt; + SHA256_CTX sha256ctx; + SHA384_CTX sha384ctx; +}; - // not found or not a valid code directory - return NULL; + +/* + * Choose among different hash algorithms. + * Higher is better, 0 => don't use at all. + */ +static const uint32_t hashPriorities[] = { + CS_HASHTYPE_SHA1, + CS_HASHTYPE_SHA256_TRUNCATED, + CS_HASHTYPE_SHA256, + CS_HASHTYPE_SHA384, +}; + +static unsigned int +hash_rank(const CS_CodeDirectory *cd) +{ + uint32_t type = cd->hashType; + unsigned int n; + + for (n = 0; n < sizeof(hashPriorities) / sizeof(hashPriorities[0]); ++n) + if (hashPriorities[n] == type) + return n + 1; + return 0; /* not supported */ } @@ -209,9 +254,10 @@ CS_CodeDirectory *findCodeDirectory( static const unsigned char * hashes( const CS_CodeDirectory *cd, - unsigned page, - char *lower_bound, - char *upper_bound) + uint32_t page, + size_t hash_len, + const char *lower_bound, + const char *upper_bound) { const unsigned char *base, *top, *hash; uint32_t nCodeSlots = ntohl(cd->nCodeSlots); @@ -260,9 +306,9 @@ hashes( /* base = address of first hash covered by scatter */ base = (const unsigned char *)cd + ntohl(cd->hashOffset) + - hashindex * SHA1_RESULTLEN; + hashindex * hash_len; /* top = address of first hash after this scatter */ - top = base + scount * SHA1_RESULTLEN; + top = base + scount * hash_len; if (!cs_valid_range(base, top, lower_bound, upper_bound) || hashindex > nCodeSlots) { @@ -278,20 +324,20 @@ hashes( scatter++; } while(1); - hash = base + (page - sbase) * SHA1_RESULTLEN; + hash = base + (page - sbase) * hash_len; } else { base = (const unsigned char *)cd + ntohl(cd->hashOffset); - top = base + nCodeSlots * SHA1_RESULTLEN; + top = base + nCodeSlots * hash_len; if (!cs_valid_range(base, top, lower_bound, upper_bound) || page > nCodeSlots) { return NULL; } assert(page < nCodeSlots); - hash = base + page * SHA1_RESULTLEN; + hash = base + page * hash_len; } - if (!cs_valid_range(hash, hash + SHA1_RESULTLEN, + if (!cs_valid_range(hash, hash + hash_len, lower_bound, upper_bound)) { hash = NULL; } @@ -315,27 +361,30 @@ hashes( static int cs_validate_codedirectory(const CS_CodeDirectory *cd, size_t length) { + struct cs_hash const *hashtype; if (length < sizeof(*cd)) return EBADEXEC; if (ntohl(cd->magic) != CSMAGIC_CODEDIRECTORY) return EBADEXEC; - if (cd->hashSize != SHA1_RESULTLEN) + if (cd->pageSize < PAGE_SHIFT_4K || cd->pageSize > PAGE_SHIFT) return EBADEXEC; - if (cd->pageSize != PAGE_SHIFT_4K) + hashtype = cs_find_md(cd->hashType); + if (hashtype == NULL) return EBADEXEC; - if (cd->hashType != CS_HASHTYPE_SHA1) + + if (cd->hashSize != hashtype->cs_size) return EBADEXEC; if (length < ntohl(cd->hashOffset)) return EBADEXEC; /* check that nSpecialSlots fits in the buffer in front of hashOffset */ - if (ntohl(cd->hashOffset) / SHA1_RESULTLEN < ntohl(cd->nSpecialSlots)) + if (ntohl(cd->hashOffset) / hashtype->cs_size < ntohl(cd->nSpecialSlots)) return EBADEXEC; /* check that codeslots fits in the buffer */ - if ((length - ntohl(cd->hashOffset)) / SHA1_RESULTLEN < ntohl(cd->nCodeSlots)) + if ((length - ntohl(cd->hashOffset)) / hashtype->cs_size < ntohl(cd->nCodeSlots)) return EBADEXEC; if (ntohl(cd->version) >= CS_SUPPORTSSCATTER && cd->scatterOffset) { @@ -343,8 +392,8 @@ cs_validate_codedirectory(const CS_CodeDirectory *cd, size_t length) if (length < ntohl(cd->scatterOffset)) return EBADEXEC; - SC_Scatter *scatter = (SC_Scatter *) - (((uint8_t *)cd) + ntohl(cd->scatterOffset)); + const SC_Scatter *scatter = (const SC_Scatter *) + (((const uint8_t *)cd) + ntohl(cd->scatterOffset)); uint32_t nPages = 0; /* @@ -378,7 +427,7 @@ cs_validate_codedirectory(const CS_CodeDirectory *cd, size_t length) /* identifier is NUL terminated string */ if (cd->identOffset) { - uint8_t *ptr = (uint8_t *)cd + ntohl(cd->identOffset); + const uint8_t *ptr = (const uint8_t *)cd + ntohl(cd->identOffset); if (memchr(ptr, 0, length - ntohl(cd->identOffset)) == NULL) return EBADEXEC; } @@ -388,7 +437,7 @@ cs_validate_codedirectory(const CS_CodeDirectory *cd, size_t length) if (length < ntohl(cd->teamOffset)) return EBADEXEC; - uint8_t *ptr = (uint8_t *)cd + ntohl(cd->teamOffset); + const uint8_t *ptr = (const uint8_t *)cd + ntohl(cd->teamOffset); if (memchr(ptr, 0, length - ntohl(cd->teamOffset)) == NULL) return EBADEXEC; } @@ -426,27 +475,43 @@ cs_validate_blob(const CS_GenericBlob *blob, size_t length) */ static int -cs_validate_csblob(const uint8_t *addr, size_t length, - const CS_CodeDirectory **rcd) +cs_validate_csblob( + const uint8_t *addr, + size_t *blob_size_p, + const CS_CodeDirectory **rcd, + const CS_GenericBlob **rentitlements) { - const CS_GenericBlob *blob = (const CS_GenericBlob *)(void *)addr; + const CS_GenericBlob *blob; int error; + size_t length, blob_size; *rcd = NULL; + *rentitlements = NULL; + blob = (const CS_GenericBlob *)(const void *)addr; + blob_size = *blob_size_p; + + length = blob_size; error = cs_validate_blob(blob, length); if (error) return error; - length = ntohl(blob->length); if (ntohl(blob->magic) == CSMAGIC_EMBEDDED_SIGNATURE) { - const CS_SuperBlob *sb = (const CS_SuperBlob *)blob; - uint32_t n, count = ntohl(sb->count); + const CS_SuperBlob *sb; + uint32_t n, count; + const CS_CodeDirectory *best_cd = NULL; + unsigned int best_rank = 0; +#if PLATFORM_WatchOS + const CS_CodeDirectory *sha1_cd = NULL; +#endif if (length < sizeof(CS_SuperBlob)) return EBADEXEC; + sb = (const CS_SuperBlob *)blob; + count = ntohl(sb->count); + /* check that the array of BlobIndex fits in the rest of the data */ if ((length - sizeof(CS_SuperBlob)) / sizeof(CS_BlobIndex) < count) return EBADEXEC; @@ -454,30 +519,95 @@ cs_validate_csblob(const uint8_t *addr, size_t length, /* now check each BlobIndex */ for (n = 0; n < count; n++) { const CS_BlobIndex *blobIndex = &sb->index[n]; - if (length < ntohl(blobIndex->offset)) + uint32_t type = ntohl(blobIndex->type); + uint32_t offset = ntohl(blobIndex->offset); + if (length < offset) return EBADEXEC; const CS_GenericBlob *subBlob = - (const CS_GenericBlob *)(void *)(addr + ntohl(blobIndex->offset)); + (const CS_GenericBlob *)(const void *)(addr + offset); - size_t subLength = length - ntohl(blobIndex->offset); + size_t subLength = length - offset; if ((error = cs_validate_blob(subBlob, subLength)) != 0) return error; subLength = ntohl(subBlob->length); /* extra validation for CDs, that is also returned */ - if (ntohl(blobIndex->type) == CSSLOT_CODEDIRECTORY) { - const CS_CodeDirectory *cd = (const CS_CodeDirectory *)subBlob; - if ((error = cs_validate_codedirectory(cd, subLength)) != 0) + if (type == CSSLOT_CODEDIRECTORY || (type >= CSSLOT_ALTERNATE_CODEDIRECTORIES && type < CSSLOT_ALTERNATE_CODEDIRECTORY_LIMIT)) { + const CS_CodeDirectory *candidate = (const CS_CodeDirectory *)subBlob; + if ((error = cs_validate_codedirectory(candidate, subLength)) != 0) return error; - *rcd = cd; + unsigned int rank = hash_rank(candidate); + if (cs_debug > 3) + printf("CodeDirectory type %d rank %d at slot 0x%x index %d\n", candidate->hashType, (int)rank, (int)type, (int)n); + if (best_cd == NULL || rank > best_rank) { + best_cd = candidate; + best_rank = rank; + + if (cs_debug > 2) + printf("using CodeDirectory type %d (rank %d)\n", (int)best_cd->hashType, best_rank); + *rcd = best_cd; + } else if (best_cd != NULL && rank == best_rank) { + /* repeat of a hash type (1:1 mapped to ranks), illegal and suspicious */ + printf("multiple hash=%d CodeDirectories in signature; rejecting\n", best_cd->hashType); + return EBADEXEC; + } +#if PLATFORM_WatchOS + if (candidate->hashType == CS_HASHTYPE_SHA1) { + if (sha1_cd != NULL) { + printf("multiple sha1 CodeDirectories in signature; rejecting\n"); + return EBADEXEC; + } + sha1_cd = candidate; + } +#endif + } else if (type == CSSLOT_ENTITLEMENTS) { + if (ntohl(subBlob->magic) != CSMAGIC_EMBEDDED_ENTITLEMENTS) { + return EBADEXEC; + } + if (*rentitlements != NULL) { + printf("multiple entitlements blobs\n"); + return EBADEXEC; + } + *rentitlements = subBlob; + } + } + +#if PLATFORM_WatchOS + /* To keep watchOS fast enough, we have to resort to sha1 for + * some code. + * + * At the time of writing this comment, known sha1 attacks are + * collision attacks (not preimage or second preimage + * attacks), which do not apply to platform binaries since + * they have a fixed hash in the trust cache. Given this + * property, we only prefer sha1 code directories for adhoc + * signatures, which always have to be in a trust cache to be + * valid (can-load-cdhash does not exist for watchOS). Those + * are, incidentally, also the platform binaries, for which we + * care about the performance hit that sha256 would bring us. + * + * Platform binaries may still contain a (not chosen) sha256 + * code directory, which keeps software updates that switch to + * sha256-only small. + */ + + if (*rcd != NULL && sha1_cd != NULL && (ntohl(sha1_cd->flags) & CS_ADHOC)) { + if (sha1_cd->flags != (*rcd)->flags) { + printf("mismatched flags between hash %d (flags: %#x) and sha1 (flags: %#x) cd.\n", + (int)(*rcd)->hashType, (*rcd)->flags, sha1_cd->flags); + *rcd = NULL; + return EBADEXEC; } + + *rcd = sha1_cd; } +#endif } else if (ntohl(blob->magic) == CSMAGIC_CODEDIRECTORY) { - if ((error = cs_validate_codedirectory((const CS_CodeDirectory *)(void *)addr, length)) != 0) + if ((error = cs_validate_codedirectory((const CS_CodeDirectory *)(const void *)addr, length)) != 0) return error; *rcd = (const CS_CodeDirectory *)blob; } else { @@ -487,6 +617,8 @@ cs_validate_csblob(const uint8_t *addr, size_t length, if (*rcd == NULL) return EBADEXEC; + *blob_size_p = blob_size; + return 0; } @@ -495,7 +627,7 @@ cs_validate_csblob(const uint8_t *addr, size_t length, * * Find an blob from the superblob/code directory. The blob must have * been been validated by cs_validate_csblob() before calling - * this. Use cs_find_blob() instead. + * this. Use csblob_find_blob() instead. * * Will also find a "raw" code directory if its stored as well as * searching the superblob. @@ -509,10 +641,10 @@ cs_validate_csblob(const uint8_t *addr, size_t length, * NULL Buffer not found */ -static const CS_GenericBlob * -cs_find_blob_bytes(const uint8_t *addr, size_t length, uint32_t type, uint32_t magic) +const CS_GenericBlob * +csblob_find_blob_bytes(const uint8_t *addr, size_t length, uint32_t type, uint32_t magic) { - const CS_GenericBlob *blob = (const CS_GenericBlob *)(void *)addr; + const CS_GenericBlob *blob = (const CS_GenericBlob *)(const void *)addr; if (ntohl(blob->magic) == CSMAGIC_EMBEDDED_SIGNATURE) { const CS_SuperBlob *sb = (const CS_SuperBlob *)blob; @@ -524,7 +656,7 @@ cs_find_blob_bytes(const uint8_t *addr, size_t length, uint32_t type, uint32_t m uint32_t offset = ntohl(sb->index[n].offset); if (length - sizeof(const CS_GenericBlob) < offset) return NULL; - blob = (const CS_GenericBlob *)(void *)(addr + offset); + blob = (const CS_GenericBlob *)(const void *)(addr + offset); if (ntohl(blob->magic) != magic) continue; return blob; @@ -538,167 +670,77 @@ cs_find_blob_bytes(const uint8_t *addr, size_t length, uint32_t type, uint32_t m const CS_GenericBlob * -cs_find_blob(struct cs_blob *csblob, uint32_t type, uint32_t magic) +csblob_find_blob(struct cs_blob *csblob, uint32_t type, uint32_t magic) { if ((csblob->csb_flags & CS_VALID) == 0) return NULL; - return cs_find_blob_bytes((const uint8_t *)csblob->csb_mem_kaddr, csblob->csb_mem_size, type, magic); + return csblob_find_blob_bytes((const uint8_t *)csblob->csb_mem_kaddr, csblob->csb_mem_size, type, magic); } static const uint8_t * -cs_find_special_slot(const CS_CodeDirectory *cd, uint32_t slot) +find_special_slot(const CS_CodeDirectory *cd, size_t slotsize, uint32_t slot) { /* there is no zero special slot since that is the first code slot */ if (ntohl(cd->nSpecialSlots) < slot || slot == 0) return NULL; - return ((const uint8_t *)cd + ntohl(cd->hashOffset) - (SHA1_RESULTLEN * slot)); + return ((const uint8_t *)cd + ntohl(cd->hashOffset) - (slotsize * slot)); } -/* - * CODESIGNING - * End of routines to navigate code signing data structures in the kernel. - */ - -/* - * ENTITLEMENTS - * Routines to navigate entitlements in the kernel. - */ - -/* Retrieve the entitlements blob for a process. - * Returns: - * EINVAL no text vnode associated with the process - * EBADEXEC invalid code signing data - * 0 no error occurred - * - * On success, out_start and out_length will point to the - * entitlements blob if found; or will be set to NULL/zero - * if there were no entitlements. - */ - -static uint8_t sha1_zero[SHA1_RESULTLEN] = { 0 }; +static uint8_t cshash_zero[CS_HASH_MAX_SIZE] = { 0 }; int -cs_entitlements_blob_get(proc_t p, void **out_start, size_t *out_length) +csblob_get_entitlements(struct cs_blob *csblob, void **out_start, size_t *out_length) { - uint8_t computed_hash[SHA1_RESULTLEN]; + uint8_t computed_hash[CS_HASH_MAX_SIZE]; const CS_GenericBlob *entitlements; const CS_CodeDirectory *code_dir; - struct cs_blob *csblob; const uint8_t *embedded_hash; - SHA1_CTX context; + union cs_hash_union context; *out_start = NULL; *out_length = 0; - if (NULL == p->p_textvp) - return EINVAL; - - if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) - return 0; + if (csblob->csb_hashtype == NULL || csblob->csb_hashtype->cs_digest_size > sizeof(computed_hash)) + return EBADEXEC; - if ((code_dir = (const CS_CodeDirectory *)cs_find_blob(csblob, CSSLOT_CODEDIRECTORY, CSMAGIC_CODEDIRECTORY)) == NULL) - return 0; + code_dir = csblob->csb_cd; - entitlements = cs_find_blob(csblob, CSSLOT_ENTITLEMENTS, CSMAGIC_EMBEDDED_ENTITLEMENTS); - embedded_hash = cs_find_special_slot(code_dir, CSSLOT_ENTITLEMENTS); + if ((csblob->csb_flags & CS_VALID) == 0) { + entitlements = NULL; + } else { + entitlements = csblob->csb_entitlements_blob; + } + embedded_hash = find_special_slot(code_dir, csblob->csb_hashtype->cs_size, CSSLOT_ENTITLEMENTS); if (embedded_hash == NULL) { if (entitlements) return EBADEXEC; return 0; - } else if (entitlements == NULL && memcmp(embedded_hash, sha1_zero, SHA1_RESULTLEN) != 0) { - return EBADEXEC; + } else if (entitlements == NULL) { + if (memcmp(embedded_hash, cshash_zero, csblob->csb_hashtype->cs_size) != 0) { + return EBADEXEC; + } else { + return 0; + } } - SHA1Init(&context); - SHA1Update(&context, entitlements, ntohl(entitlements->length)); - SHA1Final(computed_hash, &context); - if (memcmp(computed_hash, embedded_hash, SHA1_RESULTLEN) != 0) + csblob->csb_hashtype->cs_init(&context); + csblob->csb_hashtype->cs_update(&context, entitlements, ntohl(entitlements->length)); + csblob->csb_hashtype->cs_final(computed_hash, &context); + + if (memcmp(computed_hash, embedded_hash, csblob->csb_hashtype->cs_size) != 0) return EBADEXEC; - *out_start = (void *)entitlements; + *out_start = __DECONST(void *, entitlements); *out_length = ntohl(entitlements->length); return 0; } -/* Retrieve the codesign identity for a process. - * Returns: - * NULL an error occured - * string the cs_identity - */ - -const char * -cs_identity_get(proc_t p) -{ - const CS_CodeDirectory *code_dir; - struct cs_blob *csblob; - - if (NULL == p->p_textvp) - return NULL; - - if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) - return NULL; - - if ((code_dir = (const CS_CodeDirectory *)cs_find_blob(csblob, CSSLOT_CODEDIRECTORY, CSMAGIC_CODEDIRECTORY)) == NULL) - return NULL; - - if (code_dir->identOffset == 0) - return NULL; - - return ((const char *)code_dir) + ntohl(code_dir->identOffset); -} - - - -/* Retrieve the codesign blob for a process. - * Returns: - * EINVAL no text vnode associated with the process - * 0 no error occurred - * - * On success, out_start and out_length will point to the - * cms blob if found; or will be set to NULL/zero - * if there were no blob. - */ - -int -cs_blob_get(proc_t p, void **out_start, size_t *out_length) -{ - struct cs_blob *csblob; - - *out_start = NULL; - *out_length = 0; - - if (NULL == p->p_textvp) - return EINVAL; - - if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) - return 0; - - *out_start = (void *)csblob->csb_mem_kaddr; - *out_length = csblob->csb_mem_size; - - return 0; -} - -uint8_t * -cs_get_cdhash(struct proc *p) -{ - struct cs_blob *csblob; - - if (NULL == p->p_textvp) - return NULL; - - if ((csblob = ubc_cs_blob_get(p->p_textvp, -1, p->p_textoff)) == NULL) - return NULL; - - return csblob->csb_sha1; -} - /* - * ENTITLEMENTS - * End of routines to navigate entitlements in the kernel. + * CODESIGNING + * End of routines to navigate code signing data structures in the kernel. */ @@ -797,7 +839,7 @@ ubc_info_init_withsize(struct vnode *vp, off_t filesize) static int ubc_info_init_internal(vnode_t vp, int withfsize, off_t filesize) { - register struct ubc_info *uip; + struct ubc_info *uip; void * pager; int error = 0; kern_return_t kret; @@ -921,11 +963,7 @@ ubc_info_deallocate(struct ubc_info *uip) ubc_info_free(uip); } -/* - * This should be public but currently it is only used below so we - * defer making that change. - */ -static errno_t mach_to_bsd_errno(kern_return_t mach_err) +errno_t mach_to_bsd_errno(kern_return_t mach_err) { switch (mach_err) { case KERN_SUCCESS: @@ -1092,7 +1130,7 @@ errno_t ubc_setsize_ex(struct vnode *vp, off_t nsize, ubc_setsize_opts_t opts) * zero the tail of this page if it's currently * present in the cache */ - kret = ubc_create_upl(vp, lastpg, PAGE_SIZE, &upl, &pl, UPL_SET_LITE); + kret = ubc_create_upl_kernel(vp, lastpg, PAGE_SIZE, &upl, &pl, UPL_SET_LITE, VM_KERN_MEMORY_FILE); if (kret != KERN_SUCCESS) panic("ubc_setsize: ubc_create_upl (error = %d)\n", kret); @@ -1802,8 +1840,19 @@ ubc_map(vnode_t vp, int flags) error = VNOP_MMAP(vp, flags, vfs_context_current()); - if (error != EPERM) - error = 0; + /* + * rdar://problem/22587101 required that we stop propagating + * EPERM up the stack. Otherwise, we would have to funnel up + * the error at all the call sites for memory_object_map(). + * The risk is in having to undo the map/object/entry state at + * all these call sites. It would also affect more than just mmap() + * e.g. vm_remap(). + * + * if (error != EPERM) + * error = 0; + */ + + error = 0; vnode_lock_spin(vp); @@ -1826,8 +1875,13 @@ ubc_map(vnode_t vp, int flags) if (need_wakeup) wakeup(&uip->ui_flags); - if (need_ref) - vnode_ref(vp); + if (need_ref) { + /* + * Make sure we get a ref as we can't unwind from here + */ + if (vnode_ref_ext(vp, 0, VNODE_REF_FORCE)) + panic("%s : VNODE_REF_FORCE failed\n", __FUNCTION__); + } } return (error); } @@ -2281,13 +2335,26 @@ ubc_range_op( * ubc_upl_abort(), or ubc_upl_abort_range(). */ kern_return_t -ubc_create_upl( +ubc_create_upl_external( struct vnode *vp, off_t f_offset, int bufsize, upl_t *uplp, upl_page_info_t **plp, int uplflags) +{ + return (ubc_create_upl_kernel(vp, f_offset, bufsize, uplp, plp, uplflags, vm_tag_bt())); +} + +kern_return_t +ubc_create_upl_kernel( + struct vnode *vp, + off_t f_offset, + int bufsize, + upl_t *uplp, + upl_page_info_t **plp, + int uplflags, + vm_tag_t tag) { memory_object_control_t control; kern_return_t kr; @@ -2347,7 +2414,7 @@ ubc_create_upl( if (control == MEMORY_OBJECT_CONTROL_NULL) return KERN_INVALID_ARGUMENT; - kr = memory_object_upl_request(control, f_offset, bufsize, uplp, NULL, NULL, uplflags); + kr = memory_object_upl_request(control, f_offset, bufsize, uplp, NULL, NULL, uplflags, tag); if (kr == KERN_SUCCESS && plp != NULL) *plp = UPL_GET_INTERNAL_PAGE_LIST(*uplp); return kr; @@ -2718,24 +2785,50 @@ boolean_t ubc_is_mapped_writable(const struct vnode *vp) /* * CODE SIGNING */ -#define CS_BLOB_PAGEABLE 0 static volatile SInt32 cs_blob_size = 0; static volatile SInt32 cs_blob_count = 0; static SInt32 cs_blob_size_peak = 0; static UInt32 cs_blob_size_max = 0; static SInt32 cs_blob_count_peak = 0; -int cs_validation = 1; - -#ifndef SECURE_KERNEL -SYSCTL_INT(_vm, OID_AUTO, cs_validation, CTLFLAG_RW | CTLFLAG_LOCKED, &cs_validation, 0, "Do validate code signatures"); -#endif SYSCTL_INT(_vm, OID_AUTO, cs_blob_count, CTLFLAG_RD | CTLFLAG_LOCKED, (int *)(uintptr_t)&cs_blob_count, 0, "Current number of code signature blobs"); SYSCTL_INT(_vm, OID_AUTO, cs_blob_size, CTLFLAG_RD | CTLFLAG_LOCKED, (int *)(uintptr_t)&cs_blob_size, 0, "Current size of all code signature blobs"); SYSCTL_INT(_vm, OID_AUTO, cs_blob_count_peak, CTLFLAG_RD | CTLFLAG_LOCKED, &cs_blob_count_peak, 0, "Peak number of code signature blobs"); SYSCTL_INT(_vm, OID_AUTO, cs_blob_size_peak, CTLFLAG_RD | CTLFLAG_LOCKED, &cs_blob_size_peak, 0, "Peak size of code signature blobs"); SYSCTL_INT(_vm, OID_AUTO, cs_blob_size_max, CTLFLAG_RD | CTLFLAG_LOCKED, &cs_blob_size_max, 0, "Size of biggest code signature blob"); +/* + * Function: csblob_parse_teamid + * + * Description: This function returns a pointer to the team id + stored within the codedirectory of the csblob. + If the codedirectory predates team-ids, it returns + NULL. + This does not copy the name but returns a pointer to + it within the CD. Subsequently, the CD must be + available when this is used. +*/ + +static const char * +csblob_parse_teamid(struct cs_blob *csblob) +{ + const CS_CodeDirectory *cd; + + cd = csblob->csb_cd; + + if (ntohl(cd->version) < CS_SUPPORTSTEAMID) + return NULL; + + if (cd->teamOffset == 0) + return NULL; + + const char *name = ((const char *)cd) + ntohl(cd->teamOffset); + if (cs_debug > 1) + printf("found team-id %s in cdblob\n", name); + + return name; +} + kern_return_t ubc_cs_blob_allocate( @@ -2744,17 +2837,12 @@ ubc_cs_blob_allocate( { kern_return_t kr; -#if CS_BLOB_PAGEABLE - *blob_size_p = round_page(*blob_size_p); - kr = kmem_alloc(kernel_map, blob_addr_p, *blob_size_p); -#else /* CS_BLOB_PAGEABLE */ - *blob_addr_p = (vm_offset_t) kalloc(*blob_size_p); + *blob_addr_p = (vm_offset_t) kalloc_tag(*blob_size_p, VM_KERN_MEMORY_SECURITY); if (*blob_addr_p == 0) { kr = KERN_NO_SPACE; } else { kr = KERN_SUCCESS; } -#endif /* CS_BLOB_PAGEABLE */ return kr; } @@ -2763,125 +2851,258 @@ ubc_cs_blob_deallocate( vm_offset_t blob_addr, vm_size_t blob_size) { -#if CS_BLOB_PAGEABLE - kmem_free(kernel_map, blob_addr, blob_size); -#else /* CS_BLOB_PAGEABLE */ kfree((void *) blob_addr, blob_size); -#endif /* CS_BLOB_PAGEABLE */ } - -int -ubc_cs_sigpup_add( - struct vnode *vp, - vm_address_t address, - vm_size_t size) + +/* + * Some codesigned files use a lowest common denominator page size of + * 4KiB, but can be used on systems that have a runtime page size of + * 16KiB. Since faults will only occur on 16KiB ranges in + * cs_validate_range(), we can convert the original Code Directory to + * a multi-level scheme where groups of 4 hashes are combined to form + * a new hash, which represents 16KiB in the on-disk file. This can + * reduce the wired memory requirement for the Code Directory by + * 75%. Care must be taken for binaries that use the "fourk" VM pager + * for unaligned access, which may still attempt to validate on + * non-16KiB multiples for compatibility with 3rd party binaries. + */ +static boolean_t +ubc_cs_supports_multilevel_hash(struct cs_blob *blob) { - kern_return_t kr; - struct ubc_info *uip; - struct cs_blob *blob; - memory_object_control_t control; const CS_CodeDirectory *cd; - int error; - control = ubc_getobject(vp, UBC_FLAGS_NONE); - if (control == MEMORY_OBJECT_CONTROL_NULL) - return KERN_INVALID_ARGUMENT; + /* + * Only applies to binaries that ship as part of the OS, + * primarily the shared cache. + */ + if (!blob->csb_platform_binary || blob->csb_teamid != NULL) { + return FALSE; + } - if (memory_object_is_signed(control)) - return 0; + /* + * If the runtime page size matches the code signing page + * size, there is no work to do. + */ + if (PAGE_SHIFT <= blob->csb_hash_pageshift) { + return FALSE; + } - blob = (struct cs_blob *) kalloc(sizeof (struct cs_blob)); - if (blob == NULL) - return ENOMEM; + cd = blob->csb_cd; - /* fill in the new blob */ - blob->csb_cpu_type = CPU_TYPE_ANY; - blob->csb_base_offset = 0; - blob->csb_mem_size = size; - blob->csb_mem_offset = 0; - blob->csb_mem_handle = IPC_PORT_NULL; - blob->csb_mem_kaddr = address; - blob->csb_sigpup = 1; - blob->csb_platform_binary = 0; - blob->csb_teamid = NULL; - /* - * Validate the blob's contents + * There must be a valid integral multiple of hashes */ - cd = findCodeDirectory( - (const CS_SuperBlob *) address, - (char *) address, - (char *) address + blob->csb_mem_size); - if (cd == NULL) { - /* no code directory => useless blob ! */ - error = EINVAL; - goto out; + if (ntohl(cd->nCodeSlots) & (PAGE_MASK >> blob->csb_hash_pageshift)) { + return FALSE; } - blob->csb_flags = ntohl(cd->flags) | CS_VALID; - blob->csb_end_offset = round_page_4K(ntohl(cd->codeLimit)); - if((ntohl(cd->version) >= CS_SUPPORTSSCATTER) && (ntohl(cd->scatterOffset))) { + /* + * Scatter lists must also have ranges that have an integral number of hashes + */ + if ((ntohl(cd->version) >= CS_SUPPORTSSCATTER) && (ntohl(cd->scatterOffset))) { + const SC_Scatter *scatter = (const SC_Scatter*) - ((const char*)cd + ntohl(cd->scatterOffset)); - blob->csb_start_offset = ntohl(scatter->base) * PAGE_SIZE_4K; - } else { - blob->csb_start_offset = (blob->csb_end_offset - (ntohl(cd->nCodeSlots) * PAGE_SIZE_4K)); + ((const char*)cd + ntohl(cd->scatterOffset)); + /* iterate all scatter structs to make sure they are all aligned */ + do { + uint32_t sbase = ntohl(scatter->base); + uint32_t scount = ntohl(scatter->count); + + /* last scatter? */ + if (scount == 0) { + break; + } + + if (sbase & (PAGE_MASK >> blob->csb_hash_pageshift)) { + return FALSE; + } + + if (scount & (PAGE_MASK >> blob->csb_hash_pageshift)) { + return FALSE; + } + + scatter++; + } while(1); } - /* - * We don't need to check with the policy module, since the input data is supposed to be already checked - */ - - vnode_lock(vp); - if (! UBCINFOEXISTS(vp)) { - vnode_unlock(vp); - if (cs_debug) - printf("out ubc object\n"); - error = ENOENT; - goto out; + /* Covered range must be a multiple of the new page size */ + if (ntohl(cd->codeLimit) & PAGE_MASK) { + return FALSE; } - uip = vp->v_ubcinfo; - /* someone raced us to adding the code directory */ - if (uip->cs_blobs != NULL) { - if (cs_debug) - printf("sigpup: vnode already have CD ?\n"); - vnode_unlock(vp); - error = EEXIST; - goto out; + /* All checks pass */ + return TRUE; +} + +/* + * All state and preconditions were checked before, so this + * function cannot fail. + */ +static void +ubc_cs_convert_to_multilevel_hash(struct cs_blob *blob) +{ + const CS_CodeDirectory *old_cd, *cd; + CS_CodeDirectory *new_cd; + const CS_GenericBlob *entitlements; + vm_offset_t new_blob_addr; + vm_size_t new_blob_size; + vm_size_t new_cdsize; + kern_return_t kr; + int error; + size_t length; + + uint32_t hashes_per_new_hash_shift = (uint32_t)(PAGE_SHIFT - blob->csb_hash_pageshift); + + if (cs_debug > 1) { + printf("CODE SIGNING: Attempting to convert Code Directory for %lu -> %lu page shift\n", + (unsigned long)blob->csb_hash_pageshift, (unsigned long)PAGE_SHIFT); } - blob->csb_next = uip->cs_blobs; - uip->cs_blobs = blob; + old_cd = blob->csb_cd; - OSAddAtomic(+1, &cs_blob_count); - OSAddAtomic((SInt32) +blob->csb_mem_size, &cs_blob_size); + /* Up to the hashes, we can copy all data */ + new_cdsize = ntohl(old_cd->hashOffset); + new_cdsize += (ntohl(old_cd->nCodeSlots) >> hashes_per_new_hash_shift) * old_cd->hashSize; - /* mark this vnode's VM object as having "signed pages" */ - kr = memory_object_signed(uip->ui_control, TRUE); + new_blob_size = sizeof(CS_SuperBlob); + new_blob_size += sizeof(CS_BlobIndex); + new_blob_size += new_cdsize; + + if (blob->csb_entitlements_blob) { + /* We need to add a slot for the entitlements */ + new_blob_size += sizeof(CS_BlobIndex); + new_blob_size += ntohl(blob->csb_entitlements_blob->length); + } + + kr = ubc_cs_blob_allocate(&new_blob_addr, &new_blob_size); if (kr != KERN_SUCCESS) { - vnode_unlock(vp); - if (cs_debug) - printf("sigpup: not signable ?\n"); - error = ENOENT; - goto out; + if (cs_debug > 1) { + printf("CODE SIGNING: Failed to allocate memory for new Code Signing Blob: %d\n", + kr); + } + return; } - vnode_unlock(vp); + CS_SuperBlob *new_superblob; - error = 0; -out: + new_superblob = (CS_SuperBlob *)new_blob_addr; + new_superblob->magic = htonl(CSMAGIC_EMBEDDED_SIGNATURE); + new_superblob->length = htonl((uint32_t)new_blob_size); + if (blob->csb_entitlements_blob) { + vm_size_t ent_offset, cd_offset; + + cd_offset = sizeof(CS_SuperBlob) + 2 * sizeof(CS_BlobIndex); + ent_offset = cd_offset + new_cdsize; + + new_superblob->count = htonl(2); + new_superblob->index[0].type = htonl(CSSLOT_CODEDIRECTORY); + new_superblob->index[0].offset = htonl((uint32_t)cd_offset); + new_superblob->index[1].type = htonl(CSSLOT_ENTITLEMENTS); + new_superblob->index[1].offset = htonl((uint32_t)ent_offset); + + memcpy((void *)(new_blob_addr + ent_offset), blob->csb_entitlements_blob, ntohl(blob->csb_entitlements_blob->length)); + + new_cd = (CS_CodeDirectory *)(new_blob_addr + cd_offset); + } else { + vm_size_t cd_offset; + + cd_offset = sizeof(CS_SuperBlob) + 1 * sizeof(CS_BlobIndex); + + new_superblob->count = htonl(1); + new_superblob->index[0].type = htonl(CSSLOT_CODEDIRECTORY); + new_superblob->index[0].offset = htonl((uint32_t)cd_offset); + + new_cd = (CS_CodeDirectory *)new_blob_addr; + } + + memcpy(new_cd, old_cd, ntohl(old_cd->hashOffset)); + + /* Update fields in the Code Directory structure */ + new_cd->length = htonl((uint32_t)new_cdsize); + + uint32_t nCodeSlots = ntohl(new_cd->nCodeSlots); + nCodeSlots >>= hashes_per_new_hash_shift; + new_cd->nCodeSlots = htonl(nCodeSlots); + + new_cd->pageSize = PAGE_SHIFT; /* Not byte-swapped */ + + if ((ntohl(new_cd->version) >= CS_SUPPORTSSCATTER) && (ntohl(new_cd->scatterOffset))) { + SC_Scatter *scatter = (SC_Scatter*) + ((char *)new_cd + ntohl(new_cd->scatterOffset)); + /* iterate all scatter structs to scale their counts */ + do { + uint32_t scount = ntohl(scatter->count); + uint32_t sbase = ntohl(scatter->base); + + /* last scatter? */ + if (scount == 0) { + break; + } + + scount >>= hashes_per_new_hash_shift; + scatter->count = htonl(scount); + + sbase >>= hashes_per_new_hash_shift; + scatter->base = htonl(sbase); + + scatter++; + } while(1); + } + + /* For each group of hashes, hash them together */ + const unsigned char *src_base = (const unsigned char *)old_cd + ntohl(old_cd->hashOffset); + unsigned char *dst_base = (unsigned char *)new_cd + ntohl(new_cd->hashOffset); + + uint32_t hash_index; + for (hash_index = 0; hash_index < nCodeSlots; hash_index++) { + union cs_hash_union mdctx; + + uint32_t source_hash_len = old_cd->hashSize << hashes_per_new_hash_shift; + const unsigned char *src = src_base + hash_index * source_hash_len; + unsigned char *dst = dst_base + hash_index * new_cd->hashSize; + + blob->csb_hashtype->cs_init(&mdctx); + blob->csb_hashtype->cs_update(&mdctx, src, source_hash_len); + blob->csb_hashtype->cs_final(dst, &mdctx); + } + + length = new_blob_size; + error = cs_validate_csblob((const uint8_t *)new_blob_addr, &length, &cd, &entitlements); + assert(length == new_blob_size); if (error) { - if (cs_debug) - printf("sigpup: not signable ?\n"); - /* we failed; release what we allocated */ - if (blob) { - kfree(blob, sizeof (*blob)); - blob = NULL; + + if (cs_debug > 1) { + printf("CODE SIGNING: Failed to validate new Code Signing Blob: %d\n", + error); } + + ubc_cs_blob_deallocate(new_blob_addr, new_blob_size); + return; } - return error; + /* New Code Directory is ready for use, swap it out in the blob structure */ + ubc_cs_blob_deallocate(blob->csb_mem_kaddr, blob->csb_mem_size); + + blob->csb_mem_size = new_blob_size; + blob->csb_mem_kaddr = new_blob_addr; + blob->csb_cd = cd; + blob->csb_entitlements_blob = entitlements; + + /* The blob has some cached attributes of the Code Directory, so update those */ + + blob->csb_hash_firstlevel_pagesize = blob->csb_hash_pagesize; /* Save the original page size */ + + blob->csb_hash_pagesize = PAGE_SIZE; + blob->csb_hash_pagemask = PAGE_MASK; + blob->csb_hash_pageshift = PAGE_SHIFT; + blob->csb_end_offset = ntohl(cd->codeLimit); + if((ntohl(cd->version) >= CS_SUPPORTSSCATTER) && (ntohl(cd->scatterOffset))) { + const SC_Scatter *scatter = (const SC_Scatter*) + ((const char*)cd + ntohl(cd->scatterOffset)); + blob->csb_start_offset = ((off_t)ntohl(scatter->base)) * PAGE_SIZE; + } else { + blob->csb_start_offset = 0; + } } int @@ -2889,135 +3110,174 @@ ubc_cs_blob_add( struct vnode *vp, cpu_type_t cputype, off_t base_offset, - vm_address_t addr, + vm_address_t *addr, vm_size_t size, - __unused int flags) + struct image_params *imgp, + __unused int flags, + struct cs_blob **ret_blob) { kern_return_t kr; struct ubc_info *uip; struct cs_blob *blob, *oblob; int error; - ipc_port_t blob_handle; - memory_object_size_t blob_size; const CS_CodeDirectory *cd; + const CS_GenericBlob *entitlements; off_t blob_start_offset, blob_end_offset; - SHA1_CTX sha1ctxt; + union cs_hash_union mdctx; boolean_t record_mtime; - int is_platform_binary; + size_t length; record_mtime = FALSE; - is_platform_binary = 0; - - blob_handle = IPC_PORT_NULL; + if (ret_blob) + *ret_blob = NULL; blob = (struct cs_blob *) kalloc(sizeof (struct cs_blob)); if (blob == NULL) { return ENOMEM; } -#if CS_BLOB_PAGEABLE - /* get a memory entry on the blob */ - blob_size = (memory_object_size_t) size; - kr = mach_make_memory_entry_64(kernel_map, - &blob_size, - addr, - VM_PROT_READ, - &blob_handle, - IPC_PORT_NULL); - if (kr != KERN_SUCCESS) { - error = ENOMEM; - goto out; - } - if (memory_object_round_page(blob_size) != - (memory_object_size_t) round_page(size)) { - printf("ubc_cs_blob_add: size mismatch 0x%llx 0x%lx !?\n", - blob_size, (size_t)size); - panic("XXX FBDP size mismatch 0x%llx 0x%lx\n", blob_size, (size_t)size); - error = EINVAL; - goto out; - } -#else - blob_size = (memory_object_size_t) size; - blob_handle = IPC_PORT_NULL; -#endif - /* fill in the new blob */ blob->csb_cpu_type = cputype; - blob->csb_sigpup = 0; blob->csb_base_offset = base_offset; blob->csb_mem_size = size; blob->csb_mem_offset = 0; - blob->csb_mem_handle = blob_handle; - blob->csb_mem_kaddr = addr; + blob->csb_mem_kaddr = *addr; blob->csb_flags = 0; + blob->csb_signer_type = CS_SIGNER_TYPE_UNKNOWN; blob->csb_platform_binary = 0; + blob->csb_platform_path = 0; blob->csb_teamid = NULL; + blob->csb_entitlements_blob = NULL; + blob->csb_entitlements = NULL; + /* Transfer ownership. Even on error, this function will deallocate */ + *addr = 0; + /* * Validate the blob's contents */ - - error = cs_validate_csblob((const uint8_t *)addr, size, &cd); + length = (size_t) size; + error = cs_validate_csblob((const uint8_t *)blob->csb_mem_kaddr, + &length, &cd, &entitlements); if (error) { + if (cs_debug) printf("CODESIGNING: csblob invalid: %d\n", error); - blob->csb_flags = 0; - blob->csb_start_offset = 0; - blob->csb_end_offset = 0; - memset(blob->csb_sha1, 0, SHA1_RESULTLEN); - /* let the vnode checker determine if the signature is valid or not */ + /* + * The vnode checker can't make the rest of this function + * succeed if csblob validation failed, so bail */ + goto out; + } else { - const unsigned char *sha1_base; - int sha1_size; + const unsigned char *md_base; + uint8_t hash[CS_HASH_MAX_SIZE]; + int md_size; + + size = (vm_size_t) length; + assert(size <= blob->csb_mem_size); + if (size < blob->csb_mem_size) { + vm_address_t new_blob_addr; + const CS_CodeDirectory *new_cd; + const CS_GenericBlob *new_entitlements; + + kr = ubc_cs_blob_allocate(&new_blob_addr, &size); + if (kr != KERN_SUCCESS) { + if (cs_debug > 1) { + printf("CODE SIGNING: failed to " + "re-allocate blob (size " + "0x%llx->0x%llx) error 0x%x\n", + (uint64_t)blob->csb_mem_size, + (uint64_t)size, + kr); + } + } else { + memcpy((void *)new_blob_addr, (void *)blob->csb_mem_kaddr, size); + if (cd == NULL) { + new_cd = NULL; + } else { + new_cd = (void *)(((uintptr_t)cd + - (uintptr_t)blob->csb_mem_kaddr + + (uintptr_t)new_blob_addr)); + } + if (entitlements == NULL) { + new_entitlements = NULL; + } else { + new_entitlements = (void *)(((uintptr_t)entitlements + - (uintptr_t)blob->csb_mem_kaddr + + (uintptr_t)new_blob_addr)); + } +// printf("CODE SIGNING: %s:%d kaddr 0x%llx cd %p ents %p -> blob 0x%llx cd %p ents %p\n", __FUNCTION__, __LINE__, (uint64_t)blob->csb_mem_kaddr, cd, entitlements, (uint64_t)new_blob_addr, new_cd, new_entitlements); + ubc_cs_blob_deallocate(blob->csb_mem_kaddr, + blob->csb_mem_size); + blob->csb_mem_kaddr = new_blob_addr; + blob->csb_mem_size = size; + cd = new_cd; + entitlements = new_entitlements; + } + } + blob->csb_cd = cd; + blob->csb_entitlements_blob = entitlements; /* may be NULL, not yet validated */ + blob->csb_hashtype = cs_find_md(cd->hashType); + if (blob->csb_hashtype == NULL || blob->csb_hashtype->cs_digest_size > sizeof(hash)) + panic("validated CodeDirectory but unsupported type"); + + blob->csb_hash_pageshift = cd->pageSize; + blob->csb_hash_pagesize = (1U << cd->pageSize); + blob->csb_hash_pagemask = blob->csb_hash_pagesize - 1; + blob->csb_hash_firstlevel_pagesize = 0; blob->csb_flags = (ntohl(cd->flags) & CS_ALLOWED_MACHO) | CS_VALID; - blob->csb_end_offset = round_page_4K(ntohl(cd->codeLimit)); + blob->csb_end_offset = (((vm_offset_t)ntohl(cd->codeLimit) + blob->csb_hash_pagemask) & ~((vm_offset_t)blob->csb_hash_pagemask)); if((ntohl(cd->version) >= CS_SUPPORTSSCATTER) && (ntohl(cd->scatterOffset))) { const SC_Scatter *scatter = (const SC_Scatter*) ((const char*)cd + ntohl(cd->scatterOffset)); - blob->csb_start_offset = ntohl(scatter->base) * PAGE_SIZE_4K; + blob->csb_start_offset = ((off_t)ntohl(scatter->base)) * blob->csb_hash_pagesize; } else { - blob->csb_start_offset = (blob->csb_end_offset - - (ntohl(cd->nCodeSlots) * PAGE_SIZE_4K)); + blob->csb_start_offset = 0; } - /* compute the blob's SHA1 hash */ - sha1_base = (const unsigned char *) cd; - sha1_size = ntohl(cd->length); - SHA1Init(&sha1ctxt); - SHA1Update(&sha1ctxt, sha1_base, sha1_size); - SHA1Final(blob->csb_sha1, &sha1ctxt); + /* compute the blob's cdhash */ + md_base = (const unsigned char *) cd; + md_size = ntohl(cd->length); + + blob->csb_hashtype->cs_init(&mdctx); + blob->csb_hashtype->cs_update(&mdctx, md_base, md_size); + blob->csb_hashtype->cs_final(hash, &mdctx); + + memcpy(blob->csb_cdhash, hash, CS_CDHASH_LEN); } /* * Let policy module check whether the blob's signature is accepted. */ #if CONFIG_MACF - error = mac_vnode_check_signature(vp, - base_offset, - blob->csb_sha1, - (const void*)cd, - size, flags, - &is_platform_binary); + unsigned int cs_flags = blob->csb_flags; + unsigned int signer_type = blob->csb_signer_type; + error = mac_vnode_check_signature(vp, blob, imgp, &cs_flags, &signer_type, flags); + blob->csb_flags = cs_flags; + blob->csb_signer_type = signer_type; + if (error) { if (cs_debug) printf("check_signature[pid: %d], error = %d\n", current_proc()->p_pid, error); goto out; } - if ((flags & MAC_VNODE_CHECK_DYLD_SIM) && !is_platform_binary) { + if ((flags & MAC_VNODE_CHECK_DYLD_SIM) && !(blob->csb_flags & CS_PLATFORM_BINARY)) { if (cs_debug) printf("check_signature[pid: %d], is not apple signed\n", current_proc()->p_pid); error = EPERM; goto out; } -#endif - - if (is_platform_binary) { +#endif + + if (blob->csb_flags & CS_PLATFORM_BINARY) { if (cs_debug > 1) printf("check_signature[pid: %d]: platform binary\n", current_proc()->p_pid); blob->csb_platform_binary = 1; + blob->csb_platform_path = !!(blob->csb_flags & CS_PLATFORM_PATH); } else { blob->csb_platform_binary = 0; - blob->csb_teamid = csblob_get_teamid(blob); + blob->csb_platform_path = 0; + blob->csb_teamid = csblob_parse_teamid(blob); if (cs_debug > 1) { if (blob->csb_teamid) printf("check_signature[pid: %d]: team-id is %s\n", current_proc()->p_pid, blob->csb_teamid); @@ -3025,7 +3285,7 @@ ubc_cs_blob_add( printf("check_signature[pid: %d]: no team-id\n", current_proc()->p_pid); } } - + /* * Validate the blob's coverage */ @@ -3040,6 +3300,10 @@ ubc_cs_blob_add( goto out; } + if (ubc_cs_supports_multilevel_hash(blob)) { + ubc_cs_convert_to_multilevel_hash(blob); + } + vnode_lock(vp); if (! UBCINFOEXISTS(vp)) { vnode_unlock(vp); @@ -3054,8 +3318,11 @@ ubc_cs_blob_add( oblob = oblob->csb_next) { off_t oblob_start_offset, oblob_end_offset; - /* check for conflicting teamid */ - if (blob->csb_platform_binary) { //platform binary needs to be the same for app slices + if (blob->csb_signer_type != oblob->csb_signer_type) { // signer type needs to be the same for slices + vnode_unlock(vp); + error = EALREADY; + goto out; + } else if (blob->csb_platform_binary) { //platform binary needs to be the same for app slices if (!oblob->csb_platform_binary) { vnode_unlock(vp); error = EALREADY; @@ -3094,9 +3361,9 @@ ubc_cs_blob_add( (blob->csb_cpu_type == CPU_TYPE_ANY || oblob->csb_cpu_type == CPU_TYPE_ANY || blob->csb_cpu_type == oblob->csb_cpu_type) && - !bcmp(blob->csb_sha1, - oblob->csb_sha1, - SHA1_RESULTLEN)) { + !bcmp(blob->csb_cdhash, + oblob->csb_cdhash, + CS_CDHASH_LEN)) { /* * We already have this blob: * we'll return success but @@ -3112,6 +3379,8 @@ ubc_cs_blob_add( oblob->csb_cpu_type = cputype; } vnode_unlock(vp); + if (ret_blob) + *ret_blob = oblob; error = EAGAIN; goto out; } else { @@ -3185,6 +3454,9 @@ ubc_cs_blob_add( vnode_mtime(vp, &uip->cs_mtime, vfs_context_current()); } + if (ret_blob) + *ret_blob = blob; + error = 0; /* success ! */ out: @@ -3194,13 +3466,17 @@ out: /* we failed; release what we allocated */ if (blob) { + if (blob->csb_mem_kaddr) { + ubc_cs_blob_deallocate(blob->csb_mem_kaddr, blob->csb_mem_size); + blob->csb_mem_kaddr = 0; + } + if (blob->csb_entitlements != NULL) { + osobject_release(blob->csb_entitlements); + blob->csb_entitlements = NULL; + } kfree(blob, sizeof (*blob)); blob = NULL; } - if (blob_handle != IPC_PORT_NULL) { - mach_memory_entry_port_release(blob_handle); - blob_handle = IPC_PORT_NULL; - } } if (error == EAGAIN) { @@ -3210,15 +3486,47 @@ out: * blob and we want to return success. */ error = 0; - /* - * Since we're not failing, consume the data we received. - */ - ubc_cs_blob_deallocate(addr, size); } return error; } +void +csvnode_print_debug(struct vnode *vp) +{ + const char *name = NULL; + struct ubc_info *uip; + struct cs_blob *blob; + + name = vnode_getname_printable(vp); + if (name) { + printf("csvnode: name: %s\n", name); + vnode_putname_printable(name); + } + + vnode_lock_spin(vp); + + if (! UBCINFOEXISTS(vp)) { + blob = NULL; + goto out; + } + + uip = vp->v_ubcinfo; + for (blob = uip->cs_blobs; blob != NULL; blob = blob->csb_next) { + printf("csvnode: range: %lu -> %lu flags: 0x%08x platform: %s path: %s team: %s\n", + (unsigned long)blob->csb_start_offset, + (unsigned long)blob->csb_end_offset, + blob->csb_flags, + blob->csb_platform_binary ? "yes" : "no", + blob->csb_platform_path ? "yes" : "no", + blob->csb_teamid ? blob->csb_teamid : ""); + } + +out: + vnode_unlock(vp); + +} + struct cs_blob * ubc_cs_blob_get( struct vnode *vp, @@ -3253,10 +3561,6 @@ ubc_cs_blob_get( } } - if (cs_debug && blob != NULL && blob->csb_sigpup) { - printf("found sig pup blob\n"); - } - out: vnode_unlock(vp); @@ -3273,15 +3577,15 @@ ubc_cs_free( blob != NULL; blob = next_blob) { next_blob = blob->csb_next; - if (blob->csb_mem_kaddr != 0 && !blob->csb_sigpup) { + if (blob->csb_mem_kaddr != 0) { ubc_cs_blob_deallocate(blob->csb_mem_kaddr, blob->csb_mem_size); blob->csb_mem_kaddr = 0; } - if (blob->csb_mem_handle != IPC_PORT_NULL) { - mach_memory_entry_port_release(blob->csb_mem_handle); + if (blob->csb_entitlements != NULL) { + osobject_release(blob->csb_entitlements); + blob->csb_entitlements = NULL; } - blob->csb_mem_handle = IPC_PORT_NULL; OSAddAtomic(-1, &cs_blob_count); OSAddAtomic((SInt32) -blob->csb_mem_size, &cs_blob_size); kfree(blob, sizeof (*blob)); @@ -3317,36 +3621,45 @@ int ubc_cs_blob_revalidate( struct vnode *vp, struct cs_blob *blob, - __unused int flags + struct image_params *imgp, + int flags ) { int error = 0; -#if CONFIG_MACF - int is_platform_binary = 0; -#endif const CS_CodeDirectory *cd = NULL; - + const CS_GenericBlob *entitlements = NULL; + size_t size; assert(vp != NULL); assert(blob != NULL); - error = cs_validate_csblob((const uint8_t *)blob->csb_mem_kaddr, blob->csb_mem_size, &cd); + size = blob->csb_mem_size; + error = cs_validate_csblob((const uint8_t *)blob->csb_mem_kaddr, + &size, &cd, &entitlements); if (error) { if (cs_debug) { printf("CODESIGNING: csblob invalid: %d\n", error); } goto out; } + assert(size == blob->csb_mem_size); + unsigned int cs_flags = (ntohl(cd->flags) & CS_ALLOWED_MACHO) | CS_VALID; + unsigned int signer_type = CS_SIGNER_TYPE_UNKNOWN; /* callout to mac_vnode_check_signature */ #if CONFIG_MACF - error = mac_vnode_check_signature(vp, blob->csb_base_offset, blob->csb_sha1, (const void*)cd, blob->csb_cpu_type, flags, &is_platform_binary); + error = mac_vnode_check_signature(vp, blob, imgp, &cs_flags, &signer_type, flags); if (cs_debug && error) { printf("revalidate: check_signature[pid: %d], error = %d\n", current_proc()->p_pid, error); } +#else + (void)flags; + (void)signer_type; #endif /* update generation number if success */ vnode_lock_spin(vp); + blob->csb_flags = cs_flags; + blob->csb_signer_type = signer_type; if (UBCINFOEXISTS(vp)) { if (error == 0) vp->v_ubcinfo->cs_add_gen = cs_blob_generation_count; @@ -3422,36 +3735,32 @@ ubc_get_cs_mtime( unsigned long cs_validate_page_no_hash = 0; unsigned long cs_validate_page_bad_hash = 0; -boolean_t -cs_validate_page( - void *_blobs, +static boolean_t +cs_validate_hash( + struct cs_blob *blobs, memory_object_t pager, memory_object_offset_t page_offset, const void *data, + vm_size_t *bytes_processed, unsigned *tainted) { - SHA1_CTX sha1ctxt; - unsigned char actual_hash[SHA1_RESULTLEN]; - unsigned char expected_hash[SHA1_RESULTLEN]; + union cs_hash_union mdctx; + struct cs_hash const *hashtype = NULL; + unsigned char actual_hash[CS_HASH_MAX_SIZE]; + unsigned char expected_hash[CS_HASH_MAX_SIZE]; boolean_t found_hash; - struct cs_blob *blobs, *blob; + struct cs_blob *blob; const CS_CodeDirectory *cd; - const CS_SuperBlob *embedded; const unsigned char *hash; boolean_t validated; off_t offset; /* page offset in the file */ size_t size; off_t codeLimit = 0; - char *lower_bound, *upper_bound; + const char *lower_bound, *upper_bound; vm_offset_t kaddr, blob_addr; - vm_size_t ksize; - kern_return_t kr; - - offset = page_offset; /* retrieve the expected hash */ found_hash = FALSE; - blobs = (struct cs_blob *) _blobs; for (blob = blobs; blob != NULL; @@ -3463,78 +3772,39 @@ cs_validate_page( continue; } - /* map the blob in the kernel address space */ + /* blob data has been released */ kaddr = blob->csb_mem_kaddr; if (kaddr == 0) { - ksize = (vm_size_t) (blob->csb_mem_size + - blob->csb_mem_offset); - kr = vm_map(kernel_map, - &kaddr, - ksize, - 0, - VM_FLAGS_ANYWHERE, - blob->csb_mem_handle, - 0, - TRUE, - VM_PROT_READ, - VM_PROT_READ, - VM_INHERIT_NONE); - if (kr != KERN_SUCCESS) { - /* XXX FBDP what to do !? */ - printf("cs_validate_page: failed to map blob, " - "size=0x%lx kr=0x%x\n", - (size_t)blob->csb_mem_size, kr); - break; - } + continue; } - if (blob->csb_sigpup && cs_debug) - printf("checking for a sigpup CD\n"); blob_addr = kaddr + blob->csb_mem_offset; - lower_bound = CAST_DOWN(char *, blob_addr); upper_bound = lower_bound + blob->csb_mem_size; - - embedded = (const CS_SuperBlob *) blob_addr; - cd = findCodeDirectory(embedded, lower_bound, upper_bound); + + cd = blob->csb_cd; if (cd != NULL) { - if (cd->pageSize != PAGE_SHIFT_4K || - cd->hashType != CS_HASHTYPE_SHA1 || - cd->hashSize != SHA1_RESULTLEN) { - /* bogus blob ? */ - if (blob->csb_sigpup && cs_debug) - printf("page foo bogus sigpup CD\n"); - continue; - } + /* all CD's that have been injected is already validated */ - offset = page_offset - blob->csb_base_offset; - if (offset < blob->csb_start_offset || - offset >= blob->csb_end_offset) { - /* our page is not covered by this blob */ - if (blob->csb_sigpup && cs_debug) - printf("OOB sigpup CD\n"); - continue; - } + hashtype = blob->csb_hashtype; + if (hashtype == NULL) + panic("unknown hash type ?"); + if (hashtype->cs_digest_size > sizeof(actual_hash)) + panic("hash size too large"); + if (offset & blob->csb_hash_pagemask) + panic("offset not aligned to cshash boundary"); codeLimit = ntohl(cd->codeLimit); - if (blob->csb_sigpup && cs_debug) - printf("sigpup codesize %d\n", (int)codeLimit); - hash = hashes(cd, (unsigned)(offset>>PAGE_SHIFT_4K), + hash = hashes(cd, (uint32_t)(offset>>blob->csb_hash_pageshift), + hashtype->cs_size, lower_bound, upper_bound); if (hash != NULL) { - bcopy(hash, expected_hash, - sizeof (expected_hash)); + bcopy(hash, expected_hash, hashtype->cs_size); found_hash = TRUE; - if (blob->csb_sigpup && cs_debug) - printf("sigpup hash\n"); } break; - } else { - if (blob->csb_sigpup && cs_debug) - printf("sig pup had no valid CD\n"); - } } @@ -3559,23 +3829,45 @@ cs_validate_page( *tainted = 0; - size = PAGE_SIZE_4K; + size = blob->csb_hash_pagesize; + *bytes_processed = size; + const uint32_t *asha1, *esha1; if ((off_t)(offset + size) > codeLimit) { /* partial page at end of segment */ assert(offset < codeLimit); - size = (size_t) (codeLimit & PAGE_MASK_4K); + size = (size_t) (codeLimit & blob->csb_hash_pagemask); *tainted |= CS_VALIDATE_NX; } - /* compute the actual page's SHA1 hash */ - SHA1Init(&sha1ctxt); - SHA1UpdateUsePhysicalAddress(&sha1ctxt, data, size); - SHA1Final(actual_hash, &sha1ctxt); + + hashtype->cs_init(&mdctx); + + if (blob->csb_hash_firstlevel_pagesize) { + const unsigned char *partial_data = (const unsigned char *)data; + size_t i; + for (i=0; i < size;) { + union cs_hash_union partialctx; + unsigned char partial_digest[CS_HASH_MAX_SIZE]; + size_t partial_size = MIN(size-i, blob->csb_hash_firstlevel_pagesize); + + hashtype->cs_init(&partialctx); + hashtype->cs_update(&partialctx, partial_data, partial_size); + hashtype->cs_final(partial_digest, &partialctx); + + /* Update cumulative multi-level hash */ + hashtype->cs_update(&mdctx, partial_digest, hashtype->cs_size); + partial_data = partial_data + partial_size; + i += partial_size; + } + } else { + hashtype->cs_update(&mdctx, data, size); + } + hashtype->cs_final(actual_hash, &mdctx); asha1 = (const uint32_t *) actual_hash; esha1 = (const uint32_t *) expected_hash; - if (bcmp(expected_hash, actual_hash, SHA1_RESULTLEN) != 0) { + if (bcmp(expected_hash, actual_hash, hashtype->cs_size) != 0) { if (cs_debug) { printf("CODE SIGNING: cs_validate_page: " "mobj %p off 0x%llx size 0x%lx: " @@ -3603,6 +3895,53 @@ cs_validate_page( return validated; } +boolean_t +cs_validate_range( + struct vnode *vp, + memory_object_t pager, + memory_object_offset_t page_offset, + const void *data, + vm_size_t dsize, + unsigned *tainted) +{ + vm_size_t offset_in_range; + boolean_t all_subranges_validated = TRUE; /* turn false if any subrange fails */ + + struct cs_blob *blobs = ubc_get_cs_blobs(vp); + + *tainted = 0; + + for (offset_in_range = 0; + offset_in_range < dsize; + /* offset_in_range updated based on bytes processed */) { + unsigned subrange_tainted = 0; + boolean_t subrange_validated; + vm_size_t bytes_processed = 0; + + subrange_validated = cs_validate_hash(blobs, + pager, + page_offset + offset_in_range, + (const void *)((const char *)data + offset_in_range), + &bytes_processed, + &subrange_tainted); + + *tainted |= subrange_tainted; + + if (bytes_processed == 0) { + /* Cannote make forward progress, so return an error */ + all_subranges_validated = FALSE; + break; + } else if (subrange_validated == FALSE) { + all_subranges_validated = FALSE; + /* Keep going to detect other types of failures in subranges */ + } + + offset_in_range += bytes_processed; + } + + return all_subranges_validated; +} + int ubc_cs_getcdhash( vnode_t vp, @@ -3633,7 +3972,7 @@ ubc_cs_getcdhash( ret = EBADEXEC; /* XXX any better error ? */ } else { /* get the SHA1 hash of that blob */ - bcopy(blob->csb_sha1, cdhash, sizeof (blob->csb_sha1)); + bcopy(blob->csb_cdhash, cdhash, sizeof (blob->csb_cdhash)); ret = 0; } @@ -3642,8 +3981,54 @@ ubc_cs_getcdhash( return ret; } +boolean_t +ubc_cs_is_range_codesigned( + vnode_t vp, + mach_vm_offset_t start, + mach_vm_size_t size) +{ + struct cs_blob *csblob; + mach_vm_offset_t blob_start; + mach_vm_offset_t blob_end; + + if (vp == NULL) { + /* no file: no code signature */ + return FALSE; + } + if (size == 0) { + /* no range: no code signature */ + return FALSE; + } + if (start + size < start) { + /* overflow */ + return FALSE; + } + + csblob = ubc_cs_blob_get(vp, -1, start); + if (csblob == NULL) { + return FALSE; + } + + /* + * We currently check if the range is covered by a single blob, + * which should always be the case for the dyld shared cache. + * If we ever want to make this routine handle other cases, we + * would have to iterate if the blob does not cover the full range. + */ + blob_start = (mach_vm_offset_t) (csblob->csb_base_offset + + csblob->csb_start_offset); + blob_end = (mach_vm_offset_t) (csblob->csb_base_offset + + csblob->csb_end_offset); + if (blob_start > start || blob_end < (start + size)) { + /* range not fully covered by this code-signing blob */ + return FALSE; + } + + return TRUE; +} + #if CHECK_CS_VALIDATION_BITMAP -#define stob(s) ((atop_64((s)) + 07) >> 3) +#define stob(s) (((atop_64(round_page_64(s))) + 07) >> 3) extern boolean_t root_fs_upgrade_try; /*