From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755930Ab1KBRn0 (ORCPT ); Wed, 2 Nov 2011 13:43:26 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:44559 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133Ab1KBRnZ (ORCPT ); Wed, 2 Nov 2011 13:43:25 -0400 Message-ID: <4EB18138.6050400@polito.it> Date: Wed, 02 Nov 2011 18:43:20 +0100 From: Roberto Sassu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 Newsgroups: gmane.linux.kernel.lsm,gmane.linux.kernel To: David Safford CC: keyrings@linux-nfs.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, zohar@us.ibm.com, dhowells@redhat.com, jmorris@namei.org Subject: Re: [PATCH 2/2] trusted-key: added support for loading a key blob in the TPM References: <1320237682-3857-1-git-send-email-roberto.sassu@polito.it> <1320237682-3857-2-git-send-email-roberto.sassu@polito.it> <1320254766.3225.18.camel@localhost> In-Reply-To: <1320254766.3225.18.camel@localhost> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/02/2011 06:26 PM, David Safford wrote: > On Wed, 2011-11-02 at 13:41 +0100, Roberto Sassu wrote: >> The new functions 'tpm_loadkey2', 'tpm_evictkey' and 'tpm_flushspecific' >> allow to load/unload a TPM key whose blob is provided from the userspace >> interface and to use it for sealing or unsealing the symmetric key. > > This looks like a nice extension. > I'll test it out thoroughly, but for now here are a couple of > minor initial suggestions... > Thanks, i will fix them and submit a new version of the patches after receiving other comments. Roberto Sassu > dave > >> >> Signed-off-by: Roberto Sassu >> --- >> Documentation/security/keys-trusted-encrypted.txt | 6 +- >> include/linux/tpm_command.h | 6 + >> security/keys/trusted.c | 203 ++++++++++++++++++++- >> security/keys/trusted.h | 27 +++- >> 4 files changed, 234 insertions(+), 8 deletions(-) >> >> diff --git a/Documentation/security/keys-trusted-encrypted.txt b/Documentation/security/keys-trusted-encrypted.txt >> index 5f50cca..afebb58 100644 >> --- a/Documentation/security/keys-trusted-encrypted.txt >> +++ b/Documentation/security/keys-trusted-encrypted.txt >> @@ -27,8 +27,10 @@ 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 >> + keyhandle= ascii hex value of sealing key handle default 0x40000000 (SRK) >> + keyblob= ascii hex value of sealing key blob (no default) >> + srkauth= ascii hex auth for SRK key default 0x00... >> + keyauth= ascii hex auth for sealing key (not SRK) default 0x00... >> (40 ascii zeros) >> blobauth= ascii hex auth for sealed data default 0x00... >> (40 ascii zeros) >> diff --git a/include/linux/tpm_command.h b/include/linux/tpm_command.h >> index 727512e..e3348b7 100644 >> --- a/include/linux/tpm_command.h >> +++ b/include/linux/tpm_command.h >> @@ -15,7 +15,10 @@ >> #define TPM_TAG_RSP_AUTH2_COMMAND 198 >> >> /* Command Ordinals */ >> +#define TPM_ORD_EVICTKEY 34 >> +#define TPM_ORD_FLUSHSPECIFIC 186 >> #define TPM_ORD_GETRANDOM 70 >> +#define TPM_ORD_LOADKEY2 65 >> #define TPM_ORD_OSAP 11 >> #define TPM_ORD_OIAP 10 >> #define TPM_ORD_SEAL 23 >> @@ -24,5 +27,8 @@ >> /* Other constants */ >> #define SRKHANDLE 0x40000000 >> #define TPM_NONCE_SIZE 20 >> +#define TPM_RT_KEY 0x00000001 >> +#define TPM_TAG_KEY12 0x0028 >> +#define TPM_BAD_ORDINAL 10 >> >> #endif >> diff --git a/security/keys/trusted.c b/security/keys/trusted.c >> index 8777015..c332e3b 100644 >> --- a/security/keys/trusted.c >> +++ b/security/keys/trusted.c >> @@ -688,12 +688,118 @@ static int tpm_unseal(struct tpm_buf *tb, >> } >> >> /* >> + * Load a TPM key from the blob provided by userspace >> + */ >> +static int tpm_loadkey2(struct tpm_buf *tb, >> + uint32_t keyhandle, unsigned char *keyauth, >> + const unsigned char *keyblob, int keybloblen, >> + uint32_t *newhandle) >> +{ >> + unsigned char nonceodd[TPM_NONCE_SIZE]; >> + unsigned char enonce[TPM_NONCE_SIZE]; >> + unsigned char authdata[SHA1_DIGEST_SIZE]; >> + uint32_t authhandle = 0; >> + unsigned char cont = 0; >> + uint32_t ordinal; >> + int ret; >> + >> + ordinal = htonl(TPM_ORD_LOADKEY2); >> + >> + /* session for loading the key */ >> + ret = oiap(tb,&authhandle, enonce); >> + if (ret< 0) { >> + pr_info("trusted_key: oiap failed (%d)\n", ret); >> + return ret; >> + } >> + >> + /* generate odd nonce */ >> + ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE); >> + if (ret< 0) { >> + pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); >> + return ret; >> + } >> + >> + /* calculate authorization HMAC value */ >> + ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce, >> + nonceodd, cont, sizeof(uint32_t),&ordinal, >> + keybloblen, keyblob, 0, 0); >> + if (ret< 0) >> + return ret; >> + >> + /* build the request buffer */ >> + INIT_BUF(tb); >> + store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); >> + store32(tb, TPM_LOADKEY2_SIZE + keybloblen); >> + store32(tb, TPM_ORD_LOADKEY2); >> + store32(tb, keyhandle); >> + storebytes(tb, keyblob, keybloblen); >> + store32(tb, authhandle); >> + storebytes(tb, nonceodd, TPM_NONCE_SIZE); >> + store8(tb, cont); >> + storebytes(tb, authdata, SHA1_DIGEST_SIZE); >> + >> + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); >> + if (ret< 0) { >> + pr_info("trusted_key: authhmac failed (%d)\n", ret); >> + return ret; >> + } >> + >> + ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, keyauth, >> + SHA1_DIGEST_SIZE, 0, 0); >> + if (ret< 0) { >> + pr_info("trusted_key: TSS_checkhmac1 failed (%d)\n", ret); >> + return ret; >> + } >> + >> + *newhandle = LOAD32(tb->data, TPM_DATA_OFFSET); >> + return 0; >> +} >> + >> +/* >> + * Execute the FlushSpecific TPM command >> + */ >> +uint32_t tpm_flushspecific(struct tpm_buf *tb, uint32_t handle, >> + uint32_t resourcetype) > > static? > >> +{ >> + INIT_BUF(tb); >> + store16(tb, TPM_TAG_RQU_COMMAND); >> + store32(tb, TPM_FLUSHSPECIFIC_SIZE); >> + store32(tb, TPM_ORD_FLUSHSPECIFIC); >> + store32(tb, handle); >> + store32(tb, resourcetype); >> + >> + return trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); >> +} >> + >> +/* >> + * Evict a key from the TPM >> + */ >> +uint32_t tpm_evictkey(struct tpm_buf *tb, uint32_t keyhandle) > > static? > >> +{ >> + int ret; >> + >> + INIT_BUF(tb); >> + store16(tb, TPM_TAG_RQU_COMMAND); >> + store32(tb, TPM_EVICTKEY_SIZE); >> + store32(tb, TPM_ORD_EVICTKEY); >> + store32(tb, keyhandle); >> + >> + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data); >> + if (ret< 0) >> + ret = tpm_flushspecific(tb, keyhandle, TPM_RT_KEY); >> + >> + return ret; >> +} >> + >> +/* >> * Have the TPM seal(encrypt) the symmetric key >> */ >> static int key_seal(struct trusted_key_payload *p, >> struct trusted_key_options *o) >> { >> struct tpm_buf *tb; >> + uint32_t keyhandle; >> + unsigned char *parentauth; >> int ret; >> >> tb = kzalloc(sizeof *tb, GFP_KERNEL); >> @@ -703,12 +809,40 @@ static int key_seal(struct trusted_key_payload *p, >> /* include migratable flag at end of sealed key */ >> p->key[p->key_len] = p->migratable; >> >> - ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth, >> + /* set default values */ >> + keyhandle = o->keyhandle; >> + parentauth = o->srkauth; >> + >> + if (o->keytype == SEAL_keytype) { >> + parentauth = o->keyauth; >> + if (o->keyblob_len> 0) { >> + ret = tpm_loadkey2(tb, SRKHANDLE, o->srkauth, >> + o->keyblob, o->keyblob_len, >> + &keyhandle); >> + if (ret< 0) { >> + pr_info("trusted_key: loadkey2 failed (%d)\n", >> + ret); >> + goto out; >> + } >> + >> + dump_tpm_key12_handle(keyhandle); >> + } >> + } >> + >> + ret = tpm_seal(tb, o->keytype, keyhandle, parentauth, >> p->key, p->key_len + 1, p->blob,&p->blob_len, >> o->blobauth, o->pcrinfo, o->pcrinfo_len); >> if (ret< 0) >> pr_info("trusted_key: srkseal failed (%d)\n", ret); >> >> + if (o->keyblob_len> 0) { >> + int evictret = tpm_evictkey(tb, keyhandle); >> + >> + if (evictret< 0) >> + pr_info("trusted_key: evictkey failed (%d)\n", >> + evictret); >> + } >> +out: >> kfree(tb); >> return ret; >> } >> @@ -720,13 +854,33 @@ static int key_unseal(struct trusted_key_payload *p, >> struct trusted_key_options *o) >> { >> struct tpm_buf *tb; >> + uint32_t keyhandle; >> + unsigned char *parentauth; >> int ret; >> >> tb = kzalloc(sizeof *tb, GFP_KERNEL); >> if (!tb) >> return -ENOMEM; >> >> - ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, >> + /* set default values */ >> + keyhandle = o->keyhandle; >> + parentauth = o->srkauth; >> + >> + if (o->keytype == SEAL_keytype) { >> + parentauth = o->keyauth; >> + if (o->keyblob_len> 0) { >> + ret = tpm_loadkey2(tb, SRKHANDLE, o->srkauth, >> + o->keyblob, o->keyblob_len, >> + &keyhandle); >> + if (ret< 0) { >> + pr_info("trusted_key: loadkey2 failed (%d)\n", >> + ret); >> + goto out; >> + } >> + } >> + } >> + >> + ret = tpm_unseal(tb, keyhandle, parentauth, p->blob, p->blob_len, >> o->blobauth, p->key,&p->key_len); >> if (ret< 0) >> pr_info("trusted_key: srkunseal failed (%d)\n", ret); >> @@ -734,14 +888,22 @@ static int key_unseal(struct trusted_key_payload *p, >> /* pull migratable flag out of sealed key */ >> p->migratable = p->key[--p->key_len]; >> >> + if (o->keyblob_len> 0) { >> + int evictret = tpm_evictkey(tb, keyhandle); >> + >> + if (evictret< 0) >> + pr_info("trusted_key: evictkey failed (%d)\n", >> + evictret); >> + } >> +out: >> kfree(tb); >> return ret; >> } >> >> enum { >> Opt_err = -1, >> - Opt_new, Opt_load, Opt_update, >> - Opt_keyhandle, Opt_keyauth, Opt_blobauth, >> + Opt_new, Opt_load, Opt_update, Opt_srkauth, >> + Opt_keyhandle, Opt_keyblob, Opt_keyauth, Opt_blobauth, >> Opt_pcrinfo, Opt_pcrlock, Opt_migratable >> }; >> >> @@ -749,7 +911,9 @@ static const match_table_t key_tokens = { >> {Opt_new, "new"}, >> {Opt_load, "load"}, >> {Opt_update, "update"}, >> + {Opt_srkauth, "srkauth=%s"}, >> {Opt_keyhandle, "keyhandle=%s"}, >> + {Opt_keyblob, "keyblob=%s"}, >> {Opt_keyauth, "keyauth=%s"}, >> {Opt_blobauth, "blobauth=%s"}, >> {Opt_pcrinfo, "pcrinfo=%s"}, >> @@ -768,6 +932,8 @@ static int getoptions(char *c, struct trusted_key_payload *pay, >> int res; >> unsigned long handle; >> unsigned long lock; >> + uint16_t tpm_key_tag; >> + uint32_t value; >> >> while ((p = strsep(&c, " \t"))) { >> if (*p == '\0' || *p == ' ' || *p == '\t') >> @@ -788,6 +954,35 @@ static int getoptions(char *c, struct trusted_key_payload *pay, >> opt->keytype = SEAL_keytype; >> opt->keyhandle = handle; >> break; >> + case Opt_keyblob: >> + if (strlen(args[0].from)>= MAX_KEYBLOB_SIZE * 2) >> + return -EINVAL; >> + hex2bin(opt->keyblob, args[0].from, MAX_KEYBLOB_SIZE); >> + tpm_key_tag = LOAD16(opt->keyblob, 0); >> + if (tpm_key_tag != TPM_TAG_KEY12) >> + return -EINVAL; >> + opt->keytype = SEAL_keytype; >> + opt->keyblob_len = TPM_KEY12_EXPSIZE_OFFSET; >> + /* key exponent size */ >> + value = LOAD32(opt->keyblob, opt->keyblob_len); >> + opt->keyblob_len += sizeof(uint32_t) + value; >> + /* PCRINFO size */ >> + value = LOAD32(opt->keyblob, opt->keyblob_len); >> + opt->keyblob_len += sizeof(uint32_t) + value; >> + /* key length */ >> + value = LOAD32(opt->keyblob, opt->keyblob_len); >> + opt->keyblob_len += sizeof(uint32_t) + value; >> + /* enc data size */ >> + value = LOAD32(opt->keyblob, opt->keyblob_len); >> + opt->keyblob_len += sizeof(uint32_t) + value; >> + if (opt->keyblob_len>= MAX_KEYBLOB_SIZE) >> + return -EINVAL; >> + break; >> + case Opt_srkauth: >> + if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) >> + return -EINVAL; >> + hex2bin(opt->srkauth, args[0].from, SHA1_DIGEST_SIZE); >> + break; >> case Opt_keyauth: >> if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) >> return -EINVAL; >> diff --git a/security/keys/trusted.h b/security/keys/trusted.h >> index 3249fbd..6a9f373 100644 >> --- a/security/keys/trusted.h >> +++ b/security/keys/trusted.h >> @@ -3,12 +3,16 @@ >> >> /* implementation specific TPM constants */ >> #define MAX_PCRINFO_SIZE 64 >> -#define MAX_BUF_SIZE 512 >> +#define MAX_BUF_SIZE 1024 >> +#define MAX_KEYBLOB_SIZE 1024 >> #define TPM_GETRANDOM_SIZE 14 >> #define TPM_OSAP_SIZE 36 >> #define TPM_OIAP_SIZE 10 >> #define TPM_SEAL_SIZE 87 >> #define TPM_UNSEAL_SIZE 104 >> +#define TPM_LOADKEY2_SIZE 59 >> +#define TPM_EVICTKEY_SIZE 14 >> +#define TPM_FLUSHSPECIFIC_SIZE 18 >> #define TPM_SIZE_OFFSET 2 >> #define TPM_RETURN_OFFSET 6 >> #define TPM_DATA_OFFSET 10 >> @@ -17,6 +21,8 @@ >> #define LOAD32N(buffer, offset) (*(uint32_t *)&buffer[offset]) >> #define LOAD16(buffer, offset) (ntohs(*(uint16_t *)&buffer[offset])) >> >> +#define TPM_KEY12_EXPSIZE_OFFSET 31 >> + >> struct tpm_buf { >> int len; >> unsigned char data[MAX_BUF_SIZE]; >> @@ -39,6 +45,9 @@ enum { >> struct trusted_key_options { >> uint16_t keytype; >> uint32_t keyhandle; >> + uint32_t keyblob_len; >> + unsigned char keyblob[MAX_KEYBLOB_SIZE]; >> + unsigned char srkauth[SHA1_DIGEST_SIZE]; >> unsigned char keyauth[SHA1_DIGEST_SIZE]; >> unsigned char blobauth[SHA1_DIGEST_SIZE]; >> uint32_t pcrinfo_len; >> @@ -52,7 +61,12 @@ struct trusted_key_options { >> static inline void dump_options(struct trusted_key_options *o) >> { >> pr_info("trusted_key: sealing key type %d\n", o->keytype); >> - pr_info("trusted_key: sealing key handle %0X\n", o->keyhandle); >> + if (o->keyblob_len> 0) { >> + pr_info("trusted_key: sealing key blob %d\n", o->keyblob_len); >> + print_hex_dump(KERN_INFO, "keyblob ", DUMP_PREFIX_NONE, >> + 16, 1, o->keyblob, o->keyblob_len, 0); >> + } else >> + pr_info("trusted_key: sealing key handle %0X\n", o->keyhandle); >> pr_info("trusted_key: pcrlock %d\n", o->pcrlock); >> pr_info("trusted_key: pcrinfo %d\n", o->pcrinfo_len); >> print_hex_dump(KERN_INFO, "pcrinfo ", DUMP_PREFIX_NONE, >> @@ -90,6 +104,11 @@ static inline void dump_tpm_buf(unsigned char *buf) >> len = LOAD32(buf, TPM_SIZE_OFFSET); >> print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, buf, len, 0); >> } >> +static inline void dump_tpm_key12_handle(uint32_t handle) >> +{ >> + print_hex_dump(KERN_INFO, "trusted-key: key handle ", DUMP_PREFIX_NONE, >> + 16, 1,&handle, 4, 0); >> +} >> #else >> static inline void dump_options(struct trusted_key_options *o) >> { >> @@ -106,6 +125,10 @@ static inline void dump_sess(struct osapsess *s) >> static inline void dump_tpm_buf(unsigned char *buf) >> { >> } >> + >> +static inline void dump_tpm_key12_handle(uint32_t handle) >> +{ >> +} >> #endif >> >> static inline void store8(struct tpm_buf *buf, const unsigned char value) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >