#include <image.h>
#include <hexdump.h>
#include <malloc.h>
+#include <crypto/pkcs7.h>
#include <crypto/pkcs7_parser.h>
+#include <crypto/public_key.h>
#include <linux/compat.h>
#include <linux/oid_registry.h>
#include <u-boot/rsa.h>
return true;
}
-/**
- * efi_hash_msg_content - calculate a hash value of contentInfo
- * @msg: Signature
- * @hash: Pointer to a pointer to buffer holding a hash value
- * @size: Size of buffer to be returned
- *
- * Calculate a sha256 value of contentInfo in @msg and return a value in @hash.
- *
- * Return: true on success, false on error
- */
-static bool efi_hash_msg_content(struct pkcs7_message *msg, void **hash,
- size_t *size)
-{
- struct image_region regtmp;
-
- regtmp.data = msg->data;
- regtmp.size = msg->data_len;
-
- return efi_hash_regions(®tmp, 1, hash, size);
-}
-
-/**
- * efi_signature_verify - verify a signature with a certificate
- * @regs: List of regions to be authenticated
- * @signed_info: Pointer to PKCS7's signed_info
- * @cert: x509 certificate
- *
- * Signature pointed to by @signed_info against image pointed to by @regs
- * is verified by a certificate pointed to by @cert.
- * @signed_info holds a signature, including a message digest which is to be
- * compared with a hash value calculated from @regs.
- *
- * Return: true if signature is verified, false if not
- */
-static bool efi_signature_verify(struct efi_image_regions *regs,
- struct pkcs7_message *msg,
- struct pkcs7_signed_info *ps_info,
- struct x509_certificate *cert)
-{
- struct image_sign_info info;
- struct image_region regtmp[2];
- void *hash;
- size_t size;
- char c;
- bool verified;
-
- EFI_PRINT("%s: Enter, %p, %p, %p(issuer: %s, subject: %s)\n", __func__,
- regs, ps_info, cert, cert->issuer, cert->subject);
-
- verified = false;
-
- memset(&info, '\0', sizeof(info));
- info.padding = image_get_padding_algo("pkcs-1.5");
- /*
- * Note: image_get_[checksum|crypto]_algo takes an string
- * argument like "<checksum>,<crypto>"
- * TODO: support other hash algorithms
- */
- if (!strcmp(ps_info->sig->hash_algo, "sha1")) {
- info.checksum = image_get_checksum_algo("sha1,rsa2048");
- info.name = "sha1,rsa2048";
- } else if (!strcmp(ps_info->sig->hash_algo, "sha256")) {
- info.checksum = image_get_checksum_algo("sha256,rsa2048");
- info.name = "sha256,rsa2048";
- } else {
- EFI_PRINT("unknown msg digest algo: %s\n",
- ps_info->sig->hash_algo);
- goto out;
- }
- info.crypto = image_get_crypto_algo(info.name);
-
- info.key = cert->pub->key;
- info.keylen = cert->pub->keylen;
-
- /* verify signature */
- EFI_PRINT("%s: crypto: %s, signature len:%x\n", __func__,
- info.name, ps_info->sig->s_size);
- if (ps_info->aa_set & (1UL << sinfo_has_message_digest)) {
- EFI_PRINT("%s: RSA verify authentication attribute\n",
- __func__);
- /*
- * NOTE: This path will be executed only for
- * PE image authentication
- */
-
- /* check if hash matches digest first */
- EFI_PRINT("checking msg digest first, len:0x%x\n",
- ps_info->msgdigest_len);
-
-#ifdef DEBUG
- EFI_PRINT("hash in database:\n");
- print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1,
- ps_info->msgdigest, ps_info->msgdigest_len,
- false);
-#endif
- /* against contentInfo first */
- hash = NULL;
- if ((msg->data && efi_hash_msg_content(msg, &hash, &size)) ||
- /* for signed image */
- efi_hash_regions(regs->reg, regs->num, &hash, &size)) {
- /* for authenticated variable */
- if (ps_info->msgdigest_len != size ||
- memcmp(hash, ps_info->msgdigest, size)) {
- EFI_PRINT("Digest doesn't match\n");
- free(hash);
- goto out;
- }
-
- free(hash);
- } else {
- EFI_PRINT("Digesting image failed\n");
- goto out;
- }
-
- /* against digest */
- c = 0x31;
- regtmp[0].data = &c;
- regtmp[0].size = 1;
- regtmp[1].data = ps_info->authattrs;
- regtmp[1].size = ps_info->authattrs_len;
-
- if (!rsa_verify(&info, regtmp, 2,
- ps_info->sig->s, ps_info->sig->s_size))
- verified = true;
- } else {
- EFI_PRINT("%s: RSA verify content data\n", __func__);
- /* against all data */
- if (!rsa_verify(&info, regs->reg, regs->num,
- ps_info->sig->s, ps_info->sig->s_size))
- verified = true;
- }
-
-out:
- EFI_PRINT("%s: Exit, verified: %d\n", __func__, verified);
- return verified;
-}
-
/**
* efi_signature_lookup_digest - search for an image's digest in sigdb
* @regs: List of regions to be authenticated
}
/**
- * efi_signature_verify_with_list - verify a signature with signature list
- * @regs: List of regions to be authenticated
- * @msg: Signature
- * @signed_info: Pointer to PKCS7's signed_info
- * @siglist: Signature list for certificates
- * @valid_cert: x509 certificate that verifies this signature
+ * efi_lookup_certificate - find a certificate within db
+ * @msg: Signature
+ * @db: Signature database
*
- * Signature pointed to by @signed_info against image pointed to by @regs
- * is verified by signature list pointed to by @siglist.
- * Signature database is a simple concatenation of one or more
- * signature list(s).
+ * Search signature database pointed to by @db and find a certificate
+ * pointed to by @cert.
*
- * Return: true if signature is verified, false if not
+ * Return: true if found, false otherwise.
*/
-static
-bool efi_signature_verify_with_list(struct efi_image_regions *regs,
- struct pkcs7_message *msg,
- struct pkcs7_signed_info *signed_info,
- struct efi_signature_store *siglist,
- struct x509_certificate **valid_cert)
+static bool efi_lookup_certificate(struct x509_certificate *cert,
+ struct efi_signature_store *db)
{
- struct x509_certificate *cert;
+ struct efi_signature_store *siglist;
struct efi_sig_data *sig_data;
- bool verified = false;
+ struct image_region reg[1];
+ void *hash = NULL, *hash_tmp = NULL;
+ size_t size = 0;
+ bool found = false;
- EFI_PRINT("%s: Enter, %p, %p, %p, %p\n", __func__,
- regs, signed_info, siglist, valid_cert);
+ EFI_PRINT("%s: Enter, %p, %p\n", __func__, cert, db);
- if (guidcmp(&siglist->sig_type, &efi_guid_cert_x509)) {
- EFI_PRINT("Signature type is not supported: %pUl\n",
- &siglist->sig_type);
+ if (!cert || !db || !db->sig_data_list)
goto out;
- }
- /* go through the list */
- for (sig_data = siglist->sig_data_list; sig_data;
- sig_data = sig_data->next) {
- /* TODO: support owner check based on policy */
+ /*
+ * TODO: identify a certificate using sha256 digest
+ * Is there any better way?
+ */
+ /* calculate hash of TBSCertificate */
+ reg[0].data = cert->tbs;
+ reg[0].size = cert->tbs_size;
+ if (!efi_hash_regions(reg, 1, &hash, &size))
+ goto out;
- cert = x509_cert_parse(sig_data->data, sig_data->size);
- if (IS_ERR(cert)) {
- EFI_PRINT("Parsing x509 certificate failed\n");
- goto out;
+ EFI_PRINT("%s: searching for %s\n", __func__, cert->subject);
+ for (siglist = db; siglist; siglist = siglist->next) {
+ /* only with x509 certificate */
+ if (guidcmp(&siglist->sig_type, &efi_guid_cert_x509))
+ continue;
+
+ for (sig_data = siglist->sig_data_list; sig_data;
+ sig_data = sig_data->next) {
+ struct x509_certificate *cert_tmp;
+
+ cert_tmp = x509_cert_parse(sig_data->data,
+ sig_data->size);
+ if (IS_ERR_OR_NULL(cert_tmp))
+ continue;
+
+ reg[0].data = cert_tmp->tbs;
+ reg[0].size = cert_tmp->tbs_size;
+ if (!efi_hash_regions(reg, 1, &hash_tmp, NULL))
+ goto out;
+
+ x509_free_certificate(cert_tmp);
+
+ if (!memcmp(hash, hash_tmp, size)) {
+ found = true;
+ goto out;
+ }
}
+ }
+out:
+ free(hash);
+ free(hash_tmp);
- verified = efi_signature_verify(regs, msg, signed_info, cert);
+ EFI_PRINT("%s: Exit, found: %d\n", __func__, found);
+ return found;
+}
- if (verified) {
- if (valid_cert)
- *valid_cert = cert;
- else
- x509_free_certificate(cert);
- break;
+/**
+ * efi_verify_certificate - verify certificate's signature with database
+ * @signer: Certificate
+ * @db: Signature database
+ * @root: Certificate to verify @signer
+ *
+ * Determine if certificate pointed to by @signer may be verified
+ * by one of certificates in signature database pointed to by @db.
+ *
+ * Return: true if certificate is verified, false otherwise.
+ */
+static bool efi_verify_certificate(struct x509_certificate *signer,
+ struct efi_signature_store *db,
+ struct x509_certificate **root)
+{
+ struct efi_signature_store *siglist;
+ struct efi_sig_data *sig_data;
+ struct x509_certificate *cert;
+ bool verified = false;
+ int ret;
+
+ EFI_PRINT("%s: Enter, %p, %p\n", __func__, signer, db);
+
+ if (!signer || !db || !db->sig_data_list)
+ goto out;
+
+ for (siglist = db; siglist; siglist = siglist->next) {
+ /* only with x509 certificate */
+ if (guidcmp(&siglist->sig_type, &efi_guid_cert_x509))
+ continue;
+
+ for (sig_data = siglist->sig_data_list; sig_data;
+ sig_data = sig_data->next) {
+ cert = x509_cert_parse(sig_data->data, sig_data->size);
+ if (IS_ERR_OR_NULL(cert)) {
+ EFI_PRINT("Cannot parse x509 certificate\n");
+ continue;
+ }
+
+ ret = public_key_verify_signature(cert->pub,
+ signer->sig);
+ if (!ret) {
+ verified = true;
+ if (root)
+ *root = cert;
+ else
+ x509_free_certificate(cert);
+ goto out;
+ }
+ x509_free_certificate(cert);
}
- x509_free_certificate(cert);
}
out:
struct efi_signature_store *db)
{
struct pkcs7_signed_info *sinfo;
- struct efi_signature_store *siglist;
- struct x509_certificate *cert;
+ struct x509_certificate *signer;
bool verified = false;
+ int ret;
EFI_PRINT("%s: Enter, %p, %p, %p\n", __func__, regs, msg, db);
EFI_PRINT("Signed Info: digest algo: %s, pkey algo: %s\n",
sinfo->sig->hash_algo, sinfo->sig->pkey_algo);
- for (siglist = db; siglist; siglist = siglist->next)
- if (efi_signature_verify_with_list(regs, msg, sinfo,
- siglist, &cert)) {
+ EFI_PRINT("Verifying certificate chain\n");
+ signer = NULL;
+ ret = pkcs7_verify_one(msg, sinfo, &signer);
+ if (ret == -ENOPKG)
+ continue;
+
+ if (ret < 0 || !signer)
+ goto out;
+
+ if (sinfo->blacklisted)
+ continue;
+
+ EFI_PRINT("Verifying last certificate in chain\n");
+ if (signer->self_signed) {
+ if (efi_lookup_certificate(signer, db)) {
verified = true;
goto out;
}
- EFI_PRINT("Valid certificate not in \"db\"\n");
+ } else if (efi_verify_certificate(signer, db, NULL)) {
+ verified = true;
+ goto out;
+ }
+ EFI_PRINT("Valid certificate not in db\n");
}
out:
return verified;
}
-/**
- * efi_signature_verify_with_sigdb - verify signatures with db and dbx
+/*
+ * efi_signature_verify - verify signatures with db and dbx
* @regs: List of regions to be authenticated
* @msg: Signature
* @db: Signature database for trusted certificates
*
* Return: true if verification for all signatures passed, false otherwise
*/
-bool efi_signature_verify_with_sigdb(struct efi_image_regions *regs,
- struct pkcs7_message *msg,
- struct efi_signature_store *db,
- struct efi_signature_store *dbx)
+bool efi_signature_verify(struct efi_image_regions *regs,
+ struct pkcs7_message *msg,
+ struct efi_signature_store *db,
+ struct efi_signature_store *dbx)
{
- struct pkcs7_signed_info *info;
- struct efi_signature_store *siglist;
- struct x509_certificate *cert;
+ struct pkcs7_signed_info *sinfo;
+ struct x509_certificate *signer, *root;
bool verified = false;
+ int ret;
EFI_PRINT("%s: Enter, %p, %p, %p, %p\n", __func__, regs, msg, db, dbx);
if (!regs || !msg || !db || !db->sig_data_list)
goto out;
- for (info = msg->signed_infos; info; info = info->next) {
+ for (sinfo = msg->signed_infos; sinfo; sinfo = sinfo->next) {
EFI_PRINT("Signed Info: digest algo: %s, pkey algo: %s\n",
- info->sig->hash_algo, info->sig->pkey_algo);
+ sinfo->sig->hash_algo, sinfo->sig->pkey_algo);
- for (siglist = db; siglist; siglist = siglist->next) {
- if (efi_signature_verify_with_list(regs, msg, info,
- siglist, &cert))
- break;
- }
- if (!siglist) {
- EFI_PRINT("Valid certificate not in \"db\"\n");
+ /*
+ * only for authenticated variable.
+ *
+ * If this function is called for image,
+ * hash calculation will be done in
+ * pkcs7_verify_one().
+ */
+ if (!msg->data &&
+ !efi_hash_regions(regs->reg, regs->num,
+ (void **)&sinfo->sig->digest, NULL)) {
+ EFI_PRINT("Digesting an image failed\n");
goto out;
}
- if (!dbx || efi_signature_check_revocation(info, cert, dbx))
+ EFI_PRINT("Verifying certificate chain\n");
+ signer = NULL;
+ ret = pkcs7_verify_one(msg, sinfo, &signer);
+ if (ret == -ENOPKG)
continue;
- EFI_PRINT("Certificate in \"dbx\"\n");
+ if (ret < 0 || !signer)
+ goto out;
+
+ if (sinfo->blacklisted)
+ goto out;
+
+ EFI_PRINT("Verifying last certificate in chain\n");
+ if (signer->self_signed) {
+ if (efi_lookup_certificate(signer, db))
+ if (efi_signature_check_revocation(sinfo,
+ signer, dbx))
+ continue;
+ } else if (efi_verify_certificate(signer, db, &root)) {
+ bool check;
+
+ check = efi_signature_check_revocation(sinfo, root,
+ dbx);
+ x509_free_certificate(root);
+ if (check)
+ continue;
+ }
+
+ EFI_PRINT("Certificate chain didn't reach trusted CA\n");
goto out;
}
verified = true;
-
out:
EFI_PRINT("%s: Exit, verified: %d\n", __func__, verified);
return verified;
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