diff --git a/LICENSE b/LICENSE index 97c58d4662c37e15a56f149eedfb98c00e604414..0113e4b173a77583bc17bbbf213595fd9c905121 100644 --- a/LICENSE +++ b/LICENSE @@ -3,5 +3,6 @@ ./xpm/ ./qos_auth/ ./ucollection/ + ./code_sign As for the specific use of the licenses, please refer to the relevant description in the documents. diff --git a/OAT.xml b/OAT.xml index 55a93aaac5d9767f9e9f8ec15add42c0fa350918..13a8f09121676c0990873ef3de5d57c3413a2969 100644 --- a/OAT.xml +++ b/OAT.xml @@ -61,10 +61,12 @@ Note:If the text contains special characters, please escape them according to th + + diff --git a/code_sign/Kconfig b/code_sign/Kconfig new file mode 100644 index 0000000000000000000000000000000000000000..86c3581d99a5bbff86bce5b14c6c7a4275aca0b1 --- /dev/null +++ b/code_sign/Kconfig @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (c) 2023 Huawei Device Co., Ltd. +# +config SECURITY_CODE_SIGN + default y + bool "code signature" + help + code signature \ No newline at end of file diff --git a/code_sign/Makefile b/code_sign/Makefile new file mode 100644 index 0000000000000000000000000000000000000000..70482c6d6d0431731ae24870f5a8df1e3f805453 --- /dev/null +++ b/code_sign/Makefile @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (c) 2023 Huawei Device Co., Ltd. +# +obj-$(CONFIG_SECURITY_CODE_SIGN) += \ + code_sign_misc.o \ + verify_cert_chain.o + +ccflags-$(CONFIG_SECURITY_CODE_SIGN) += \ + -I$(srctree)/security/selinux/include \ + -I$(srctree)/security/selinux + +$(addprefix $(obj)/,$(obj-y)): $(obj)/flask.h + +quiet_cmd_flask = GEN $(obj)/flask.h $(obj)/av_permissions.h + cmd_flask = scripts/selinux/genheaders/genheaders $(obj)/flask.h $(obj)/av_permissions.h + +targets += flask.h av_permissions.h +$(obj)/flask.h: $(srctree)/security/selinux/include/classmap.h FORCE + $(call if_changed,flask) diff --git a/code_sign/apply_code_sign.sh b/code_sign/apply_code_sign.sh new file mode 100755 index 0000000000000000000000000000000000000000..6098a16de610d3d626dcca024835ccd29f51cd7a --- /dev/null +++ b/code_sign/apply_code_sign.sh @@ -0,0 +1,28 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2023 Huawei Device Co., Ltd. +# + +set -e + +OHOS_SOURCE_ROOT=$1 +KERNEL_BUILD_ROOT=$2 +PRODUCT_NAME=$3 +KERNEL_VERSION=$4 +CODE_SIGN_SOURCE_ROOT=$OHOS_SOURCE_ROOT/kernel/linux/common_modules/code_sign + +function main() +{ + pushd . + + if [ ! -d "$KERNEL_BUILD_ROOT/fs/code_sign" ]; then + mkdir $KERNEL_BUILD_ROOT/fs/code_sign + fi + + cd $KERNEL_BUILD_ROOT/fs/code_sign + ln -s -f $(realpath --relative-to=$KERNEL_BUILD_ROOT/fs/code_sign $CODE_SIGN_SOURCE_ROOT)/* ./ + + popd +} + +main diff --git a/code_sign/code_sign_misc.c b/code_sign/code_sign_misc.c new file mode 100644 index 0000000000000000000000000000000000000000..3885aec14f60b961b52720e8447cf4def27c0143 --- /dev/null +++ b/code_sign/code_sign_misc.c @@ -0,0 +1,288 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2023 Huawei Device Co., Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include <../../crypto/asymmetric_keys/pkcs7_parser.h> +#include "avc.h" +#include "objsec.h" +#include + +struct cert_source *root, *cur; + +struct rb_root cert_chain_tree = RB_ROOT; + +struct cert_source *cert_chain_search(struct rb_root *root, struct x509_certificate *cert) +{ + pr_info("enter cert_chain_search\n"); + struct rb_node *node = root->rb_node; + + while (node) { + struct cert_source *source = container_of(node, struct cert_source, node); + + int result = strcmp(source->subject, cert->subject); + pr_info("source->subject '%s', cert->subject '%s'\n", source->subject, cert->subject); + + if (result < 0) { + node = node->rb_left; + } else if (result > 0) { + node = node->rb_right; + } else { + result = strcmp(source->issuer, cert->issuer); + pr_info("source->issuer '%s', cert->issuer '%s'\n", source->issuer, cert->issuer); + if (result < 0) { + node = node->rb_left; + } else if (result > 0) { + node = node->rb_right; + } else { + pr_info("matched\n"); + return source; + } + } + } + pr_err("cert not found\n"); + return NULL; +} + +struct cert_source *find_match(struct x509_certificate *cert) +{ + pr_info("enter find_match\n"); + return cert_chain_search(&cert_chain_tree, cert); +} + +void cert_chain_insert(struct rb_root *root, struct cert_source *cert) +{ + struct rb_node **new = &(root->rb_node), *parent = NULL; + + while (*new) { + struct cert_source *this = container_of(*new, struct cert_source, node); + int result = strcmp(cert->subject, this->subject); + + parent = *new; + if (result < 0) { + new = &((*new)->rb_left); + } else if (result > 0) { + new = &((*new)->rb_right); + } else { + result = strcmp(cert->issuer, this->issuer); + if (result < 0) { + new = &((*new)->rb_left); + } else if (result > 0) { + new = &((*new)->rb_right); + } else { + pr_info("cert existed\n"); + return; + } + } + } + + // add new node + rb_link_node(&cert->node, parent, new); + rb_insert_color(&cert->node, root); +} + +int code_sign_open(struct inode *inode, struct file *filp) +{ + return 0; +} + +int code_sign_release(struct inode *inode, struct file *filp) +{ + return 0; +} + +/* + * Fabricate and save the issuer and subject names. See x509_fabricate_name in x509_cert_parse.c. + */ +int fabricate_name(char *origin_name, int len, char **subject) +{ + char *common_name, *orgnazition, *email; + char *attr, *value; + + for (attr = strsep(&origin_name, "="); origin_name != NULL; attr = strsep(&origin_name, "=")) { + value = strsep(&origin_name, ","); + attr = strim(attr); + + if (strlen(attr) == 2 && memcmp(attr, "CN", 2) == 0) + common_name = value; + else if (strlen(attr) == 1 && memcmp(attr, "O", 1) == 0) + orgnazition = value; + else if (strlen(attr) == 1 && memcmp(attr, "E", 1) == 0) + email = value; + } + + if (common_name && orgnazition) { + if (memcmp(common_name, orgnazition, strlen(orgnazition)) == 0) + goto return_common_name; + if (strlen(common_name) >= 7 && strlen(orgnazition) >= 7 && memcmp(common_name, orgnazition, 7) == 0) + goto return_common_name; + + char* name = kzalloc(strlen(common_name) + 2 + strlen(orgnazition) + 1, GFP_KERNEL); + if (!name) + return -ENOMEM; + + memcpy(name, orgnazition, strlen(orgnazition)); + name[strlen(orgnazition) + 0] = ':'; + name[strlen(orgnazition) + 1] = ' '; + memcpy(name + strlen(orgnazition) + 2, common_name, strlen(common_name)); + name[strlen(orgnazition) + 2 + strlen(common_name)] = 0; + *subject = name; + return 0; + } else if (common_name) { +return_common_name: + *subject = common_name; + return 0; + } else if (orgnazition) { + *subject = orgnazition; + return 0; + } else if (email) { + *subject = email; + return 0; + } + + return -EINVAL; +} + +int code_sign_avc_has_perm(u16 tclass, u32 requested) +{ + struct av_decision avd; + u32 sid = current_sid(); + int rc, rc2; + + rc = avc_has_perm_noaudit(&selinux_state, sid, sid, tclass, requested, + AVC_STRICT, &avd); + rc2 = avc_audit(&selinux_state, sid, sid, tclass, requested, &avd, rc, + NULL, AVC_STRICT); + if (rc2) + return rc2; + + return rc; +} + +long code_sign_ioctl(struct file *filp, unsigned int cmd, unsigned long args) +{ + if (code_sign_avc_has_perm(SECCLASS_CODE_SIGN, CODE_SIGN__ACCESS_CERT_CHAIN)) + return -EPERM; + + struct cert_source *source = kzalloc(sizeof(struct cert_source), GFP_KERNEL); + + if (!source) + return -ENOMEM; + + if (cmd != WRITE_CERT_CHAIN) { + pr_err("code_sign cmd error, cmd:%d\n", cmd); + return -EINVAL; + } + + struct cert_chain_info info; + + int ret = copy_from_user(&info, args, sizeof(struct cert_chain_info)); + if (ret) { + pr_err("cmd copy_from_user failed %d\n", ret); + ret = -ENOMEM; + goto copy_source_failed; + } + + char *origin_subject = kzalloc(info.signing_length, GFP_KERNEL); + if (!origin_subject) { + ret = -ENOMEM; + goto copy_source_failed; + } + + ret = copy_from_user(origin_subject, u64_to_user_ptr(info.signing_ptr), info.signing_length); + if (ret) { + pr_err("copy_from_user get signing failed\n"); + ret = -EFAULT; + goto copy_subject_failed; + } + + if (fabricate_name(origin_subject, info.signing_length, &source->subject)) { + pr_err("Fabricate subject failed\n"); + goto copy_subject_failed; + } + + char *origin_issuer = kzalloc(info.issuer_length, GFP_KERNEL); + if (!origin_issuer) { + ret = -ENOMEM; + goto copy_subject_failed; + } + + ret = copy_from_user(origin_issuer, u64_to_user_ptr(info.issuer_ptr), info.issuer_length); + if (ret) { + pr_err("copy_from_user get issuer failed\n"); + ret = -EFAULT; + goto copy_issuer_failed; + } + + if (fabricate_name(origin_issuer, info.issuer_length, &source->issuer)) { + pr_err("Fabricate issuer failed\n"); + goto copy_issuer_failed; + } + + source->max_path_depth = info.path; + + pr_info("signing = '%s', issuer = '%s', max_path_depth = %d\n", source->subject, source->issuer, source->max_path_depth); + + // insert rb_tree + cert_chain_insert(&cert_chain_tree, source); + + return ret; + +copy_issuer_failed: + kfree(origin_issuer); + kfree(source->issuer); +copy_subject_failed: + kfree(origin_subject); + kfree(source->subject); +copy_source_failed: + kfree(source); + return ret; +} + +const struct file_operations code_sign_ops = { + .owner = THIS_MODULE, + .open = code_sign_open, + .release = code_sign_release, + .unlocked_ioctl = code_sign_ioctl, + .compat_ioctl = code_sign_ioctl, +}; + +static struct miscdevice code_sign_misc = { + .minor = MISC_DYNAMIC_MINOR, + .name = "code_sign", + .fops = &code_sign_ops, +}; + +static void code_sign_register_hck_hooks(void) +{ + REGISTER_HCK_LITE_HOOK(fsverity_verity_certchain_lhck, fsverity_verity_certchain); +} + +static int __init code_sign_init(void) +{ + pr_info("INIT\n"); + + code_sign_register_hck_hooks(); + + return misc_register(&code_sign_misc); +} + +static void __exit code_sign_exit(void) +{ + misc_deregister(&code_sign_misc); + + pr_info("EXIT\n"); +} + +module_init(code_sign_init); +module_exit(code_sign_exit); + +MODULE_LICENSE("GPL"); diff --git a/code_sign/code_sign_misc.h b/code_sign/code_sign_misc.h new file mode 100644 index 0000000000000000000000000000000000000000..f424e672f1a79a4c16fde673aff243e9e8b1d97e --- /dev/null +++ b/code_sign/code_sign_misc.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * + * Copyright (c) 2023 Huawei Device Co., Ltd. + */ + +#include + +#ifndef _CODE_SIGN_H +#define _CODE_SIGN_H + +struct cert_chain_info { + __u32 signing_length; + __u32 issuer_length; + __u64 signing_ptr; + __u64 issuer_ptr; + __u32 path; + __u8 __reserved[36]; +}; + +struct cert_source { + char *subject; + char *issuer; + int max_path_depth; + struct rb_node node; +}; + +#define WRITE_CERT_CHAIN _IOW('k', 1, struct cert_chain_info) + +/* + * cert_chain.c + */ + +struct cert_source *find_match(struct x509_certificate *cert); + +#endif /* _CODE_SIGN_H */ diff --git a/code_sign/verify_cert_chain.c b/code_sign/verify_cert_chain.c new file mode 100644 index 0000000000000000000000000000000000000000..e66ef51324c9a69755dce11a4b9ec6d103b60fb1 --- /dev/null +++ b/code_sign/verify_cert_chain.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2023 Huawei Device Co., Ltd. + */ + +#include +#include +#include +#include +#include +#include <../../crypto/asymmetric_keys/pkcs7_parser.h> +#include +#include + +/* + * Find the key (X.509 certificate) to use to verify a PKCS#7 message. PKCS#7 + * uses the issuer's name and the issuing certificate serial number for + * matching purposes. These must match the certificate issuer's name (not + * subject's name) and the certificate serial number [RFC 2315 6.7]. + */ +static int pkcs7_find_key(struct pkcs7_message *pkcs7, + struct pkcs7_signed_info *sinfo) +{ + struct x509_certificate *x509; + unsigned certix = 1; + + kenter("%u", sinfo->index); + pr_info("sinfo->index %u", sinfo->index); + + for (x509 = pkcs7->certs; x509; x509 = x509->next, certix++) { + /* I'm _assuming_ that the generator of the PKCS#7 message will + * encode the fields from the X.509 cert in the same way in the + * PKCS#7 message - but I can't be 100% sure of that. It's + * possible this will need element-by-element comparison. + */ + if (!asymmetric_key_id_same(x509->id, sinfo->sig->auth_ids[0])) { + pr_warn("Sig %u: X.509->id and PKCS#7 sinfo->sig->auth_ids[0] don't match\n", sinfo->index, x509->id, sinfo->sig->auth_ids[0]); + continue; + } + pr_info("Sig %u: Found cert serial match X.509[%u]\n", + sinfo->index, certix); + + if (strcmp(x509->pub->pkey_algo, sinfo->sig->pkey_algo) != 0 && (strncmp(x509->pub->pkey_algo, "ecdsa-", 6) != 0 || strcmp(x509->sig->pkey_algo, "ecdsa") != 0)) { + pr_warn("Sig %u: X.509 algo and PKCS#7 sig algo don't match\n", sinfo->index); + continue; + } + + sinfo->signer = x509; + return 0; + } + + /* The relevant X.509 cert isn't found here, but it might be found in + * the trust keyring. + */ + pr_info("Sig %u: Issuing X.509 cert not found (#%*phN)\n", + sinfo->index, + sinfo->sig->auth_ids[0]->len, sinfo->sig->auth_ids[0]->data); + return 0; +} + +void fsverity_verity_certchain(const void *raw_pkcs7, size_t pkcs7_len, int *ret) +{ + pr_info("enter fsverity_verity_certchain\n"); + struct pkcs7_message *pkcs7; + struct pkcs7_signed_info *sinfo; + int cert_chain_depth = 1; + + pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len); + if (IS_ERR(pkcs7)) { + pr_err("parse pkcs7 message failed\n"); + *ret = PTR_ERR(pkcs7); + return; + } + + if (!pkcs7->signed_infos) { + pr_err("No found signed_info\n"); + *ret = -EKEYREJECTED; + return; + } + + for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) { + /* Find the key for the signature if there is one */ + *ret = pkcs7_find_key(pkcs7, sinfo); + if (*ret) { + pr_err("pkcs7 not find key\n"); + return; + } + + struct x509_certificate *signer = sinfo->signer; + + if (!signer) { + pr_err("No found signer\n"); + *ret = -EINVAL; + return; + } + + struct cert_source *source = find_match(signer); + if (source) { + // cal cert chain depth + char *issuer = signer->issuer; + for (; signer; signer = signer->next) { + if (signer->subject && (strcmp(signer->subject, issuer) == 0)) { + cert_chain_depth++; + issuer = signer->issuer; + } else + break; + } + if (cert_chain_depth == source->max_path_depth) + return; + } + } + + pr_err("Cannot find match\n"); + *ret = -EINVAL; +} diff --git a/code_sign/verify_cert_chain.h b/code_sign/verify_cert_chain.h new file mode 100644 index 0000000000000000000000000000000000000000..ad3eb5df8da3dbc2a0f9681011faa614fc8fc18f --- /dev/null +++ b/code_sign/verify_cert_chain.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * + * Copyright (c) 2023 Huawei Device Co., Ltd. + */ + +#ifndef _VERIFY_CERT_CHAIN_H +#define _VERIFY_CERT_CHAIN_H + +/* + * verify_cert_chain.c + */ + +void fsverity_verity_certchain(const void *raw_pkcs7, size_t pkcs7_len, int *ret); + +#endif /* _VERIFY_CERT_CHAIN_H */