Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932095AbbKQQ17 (ORCPT ); Tue, 17 Nov 2015 11:27:59 -0500 Received: from mga14.intel.com ([192.55.52.115]:32307 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754207AbbKQQ14 (ORCPT ); Tue, 17 Nov 2015 11:27:56 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,308,1444719600"; d="scan'208";a="687643942" From: Jarkko Sakkinen To: Peter Huewe , Marcel Selhorst , David Howells Cc: Jarkko Sakkinen , Mimi Zohar , David Safford , Jonathan Corbet , Jason Gunthorpe , James Morris , "Serge E. Hallyn" , linux-security-module@vger.kernel.org (open list:KEYS-ENCRYPTED), keyrings@vger.kernel.org (open list:KEYS-ENCRYPTED), linux-doc@vger.kernel.org (open list:DOCUMENTATION), linux-kernel@vger.kernel.org (open list), tpmdd-devel@lists.sourceforge.net (moderated list:TPM DEVICE DRIVER) Subject: [PATCH 2/2] keys, trusted: seal with a policy Date: Tue, 17 Nov 2015 18:27:22 +0200 Message-Id: <1447777643-10777-3-git-send-email-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1447777643-10777-1-git-send-email-jarkko.sakkinen@linux.intel.com> References: <1447777643-10777-1-git-send-email-jarkko.sakkinen@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8456 Lines: 244 Support for sealing with a authorization policy. Two new options for trusted keys: * 'policydigest=': provide an auth policy digest for sealing. * 'policyhandle=': provide a policy session handle for unsealing. Signed-off-by: Jarkko Sakkinen --- Documentation/security/keys-trusted-encrypted.txt | 34 ++++++++++------- drivers/char/tpm/tpm2-cmd.c | 24 ++++++++++-- include/keys/trusted-type.h | 3 ++ security/keys/trusted.c | 46 ++++++++++++++++++++++- 4 files changed, 87 insertions(+), 20 deletions(-) diff --git a/Documentation/security/keys-trusted-encrypted.txt b/Documentation/security/keys-trusted-encrypted.txt index fd2565b..324ddf5 100644 --- a/Documentation/security/keys-trusted-encrypted.txt +++ b/Documentation/security/keys-trusted-encrypted.txt @@ -27,20 +27,26 @@ Usage: keyctl print keyid options: - keyhandle= ascii hex value of sealing key default 0x40000000 (SRK) - keyauth= ascii hex auth for sealing key default 0x00...i - (40 ascii zeros) - blobauth= ascii hex auth for sealed data default 0x00... - (40 ascii zeros) - blobauth= ascii hex auth for sealed data default 0x00... - (40 ascii zeros) - pcrinfo= ascii hex of PCR_INFO or PCR_INFO_LONG (no default) - pcrlock= pcr number to be extended to "lock" blob - migratable= 0|1 indicating permission to reseal to new PCR values, - default 1 (resealing allowed) - hash= hash algorithm name as a string. For TPM 1.x the only - allowed value is sha1. For TPM 2.x the allowed values - are sha1, sha256, sha384, sha512 and sm3-256. + keyhandle= ascii hex value of sealing key default 0x40000000 (SRK) + keyauth= ascii hex auth for sealing key default 0x00...i + (40 ascii zeros) + blobauth= ascii hex auth for sealed data default 0x00... + (40 ascii zeros) + blobauth= ascii hex auth for sealed data default 0x00... + (40 ascii zeros) + pcrinfo= ascii hex of PCR_INFO or PCR_INFO_LONG (no default) + pcrlock= pcr number to be extended to "lock" blob + migratable= 0|1 indicating permission to reseal to new PCR values, + default 1 (resealing allowed) + hash= hash algorithm name as a string. For TPM 1.x the only + allowed value is sha1. For TPM 2.x the allowed values + are sha1, sha256, sha384, sha512 and sm3-256. + policydigest= digest for the authorization policy. must be calculated + with the same hash algorithm as specified by the 'hash=' + option. + policyhandle= handle to an authorization policy session that defines the + same policy and with the same hash algorithm as was used to + seal the key. "keyctl print" returns an ascii hex copy of the sealed key, which is in standard TPM_STORED_DATA format. The key length for new keys are always in bytes. diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index d9d0822..45a6340 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -478,12 +478,26 @@ int tpm2_seal_trusted(struct tpm_chip *chip, tpm_buf_append_u8(&buf, payload->migratable); /* public */ - tpm_buf_append_u16(&buf, 14); + if (options->policydigest) + tpm_buf_append_u16(&buf, 14 + options->digest_len); + else + tpm_buf_append_u16(&buf, 14); tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH); tpm_buf_append_u16(&buf, hash); - tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH); - tpm_buf_append_u16(&buf, 0); /* policy digest size */ + + /* policy */ + if (options->policydigest) { + tpm_buf_append_u32(&buf, 0); + tpm_buf_append_u16(&buf, options->digest_len); + tpm_buf_append(&buf, options->policydigest, + options->digest_len); + } else { + tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH); + tpm_buf_append_u16(&buf, 0); + } + + /* public parameters */ tpm_buf_append_u16(&buf, TPM2_ALG_NULL); tpm_buf_append_u16(&buf, 0); @@ -613,7 +627,9 @@ static int tpm2_unseal(struct tpm_chip *chip, return rc; tpm_buf_append_u32(&buf, blob_handle); - tpm2_buf_append_auth(&buf, TPM2_RS_PW, + tpm2_buf_append_auth(&buf, + options->policyhandle ? + options->policyhandle : TPM2_RS_PW, NULL /* nonce */, 0, 0 /* session_attributes */, options->blobauth /* hmac */, diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a6a1008..2c3f9f7 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -37,6 +37,9 @@ struct trusted_key_options { unsigned char pcrinfo[MAX_PCRINFO_SIZE]; int pcrlock; uint32_t hash; + uint32_t digest_len; + unsigned char *policydigest; + uint32_t policyhandle; }; extern struct key_type key_type_trusted; diff --git a/security/keys/trusted.c b/security/keys/trusted.c index b5b0a55..b726a83 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -713,6 +713,8 @@ enum { Opt_keyhandle, Opt_keyauth, Opt_blobauth, Opt_pcrinfo, Opt_pcrlock, Opt_migratable, Opt_hash, + Opt_policydigest, + Opt_policyhandle, }; static const match_table_t key_tokens = { @@ -726,6 +728,8 @@ static const match_table_t key_tokens = { {Opt_pcrlock, "pcrlock=%s"}, {Opt_migratable, "migratable=%s"}, {Opt_hash, "hash=%s"}, + {Opt_policydigest, "policydigest=%s"}, + {Opt_policyhandle, "policyhandle=%s"}, {Opt_err, NULL} }; @@ -739,6 +743,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay, int res; unsigned long handle; unsigned long lock; + unsigned int policydigest_len; int i; int tpm2; @@ -747,6 +752,8 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return tpm2; opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1; + opt->digest_len = hash_digest_size[opt->hash]; + policydigest_len = opt->digest_len; while ((p = strsep(&c, " \t"))) { if (*p == '\0' || *p == ' ' || *p == '\t') @@ -802,6 +809,8 @@ static int getoptions(char *c, struct trusted_key_payload *pay, for (i = 0; i < HASH_ALGO__LAST; i++) { if (!strcmp(args[0].from, hash_algo_name[i])) { opt->hash = i; + opt->digest_len = + hash_digest_size[opt->hash]; break; } } @@ -812,10 +821,37 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return -EINVAL; } break; + case Opt_policydigest: + if (!tpm2 || + strlen(args[0].from) != (2 * opt->digest_len)) + return -EINVAL; + kfree(opt->policydigest); + opt->policydigest = kzalloc(opt->digest_len, + GFP_KERNEL); + if (!opt->policydigest) + return -ENOMEM; + res = hex2bin(opt->policydigest, args[0].from, + opt->digest_len); + if (res < 0) + return -EINVAL; + policydigest_len = opt->digest_len; + break; + case Opt_policyhandle: + if (!tpm2) + return -EINVAL; + res = kstrtoul(args[0].from, 16, &handle); + if (res < 0) + return -EINVAL; + opt->policyhandle = handle; + break; default: return -EINVAL; } } + + if (opt->policydigest && policydigest_len != opt->digest_len) + return -EINVAL; + return 0; } @@ -904,6 +940,12 @@ static struct trusted_key_options *trusted_options_alloc(void) return options; } +static void trusted_options_free(struct trusted_key_options *options) +{ + kfree(options->policydigest); + kfree(options); +} + static struct trusted_key_payload *trusted_payload_alloc(struct key *key) { struct trusted_key_payload *p = NULL; @@ -1010,7 +1052,7 @@ static int trusted_instantiate(struct key *key, ret = pcrlock(options->pcrlock); out: kfree(datablob); - kfree(options); + trusted_options_free(options); if (!ret) rcu_assign_keypointer(key, payload); else @@ -1098,7 +1140,7 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep) call_rcu(&p->rcu, trusted_rcu_free); out: kfree(datablob); - kfree(new_o); + trusted_options_free(new_o); return ret; } -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/