Re: [PATCH] KEYS: remove support for asym_tpm keys
From: Jarkko Sakkinen
Date: Tue Feb 08 2022 - 04:31:39 EST
On Fri, Jan 28, 2022 at 11:56:55AM -0800, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> asym_tpm keys are tied to TPM v1.2, which uses outdated crypto and has
> been deprecated in favor of TPM v2.0 for over 7 years. A very quick
> look at this code also immediately found some memory safety bugs
> (https://lore.kernel.org/r/20220113235440.90439-2-ebiggers@xxxxxxxxxx).
> Note that this code is reachable by unprivileged users.
>
> According to Jarkko (one of the keyrings subsystem maintainers), this
> code has no practical use cases, and he isn't willing to maintain it
> (https://lore.kernel.org/r/YfFZPbKkgYJGWu1Q@xxxxxx).
>
> Therefore, let's remove it.
>
> Note that this feature didn't have any documentation or tests, so we
> don't need to worry about removing those.
>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> Cc: Denis Kenzior <denkenz@xxxxxxxxx>
> Cc: James Morris <jmorris@xxxxxxxxx>
> Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
> crypto/asymmetric_keys/Kconfig | 21 -
> crypto/asymmetric_keys/Makefile | 12 -
> crypto/asymmetric_keys/asym_tpm.c | 957 ----------------------------
> crypto/asymmetric_keys/tpm.asn1 | 5 -
> crypto/asymmetric_keys/tpm_parser.c | 102 ---
> include/crypto/asym_tpm_subtype.h | 19 -
> 6 files changed, 1116 deletions(-)
> delete mode 100644 crypto/asymmetric_keys/asym_tpm.c
> delete mode 100644 crypto/asymmetric_keys/tpm.asn1
> delete mode 100644 crypto/asymmetric_keys/tpm_parser.c
> delete mode 100644 include/crypto/asym_tpm_subtype.h
>
> diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
> index 1f1f004dc7577..460bc5d0a828c 100644
> --- a/crypto/asymmetric_keys/Kconfig
> +++ b/crypto/asymmetric_keys/Kconfig
> @@ -22,18 +22,6 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
> appropriate hash algorithms (such as SHA-1) must be available.
> ENOPKG will be reported if the requisite algorithm is unavailable.
>
> -config ASYMMETRIC_TPM_KEY_SUBTYPE
> - tristate "Asymmetric TPM backed private key subtype"
> - depends on TCG_TPM
> - depends on TRUSTED_KEYS
> - select CRYPTO_HMAC
> - select CRYPTO_SHA1
> - select CRYPTO_HASH_INFO
> - help
> - This option provides support for TPM backed private key type handling.
> - Operations such as sign, verify, encrypt, decrypt are performed by
> - the TPM after the private key is loaded.
> -
> config X509_CERTIFICATE_PARSER
> tristate "X.509 certificate parser"
> depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
> @@ -54,15 +42,6 @@ config PKCS8_PRIVATE_KEY_PARSER
> private key data and provides the ability to instantiate a crypto key
> from that data.
>
> -config TPM_KEY_PARSER
> - tristate "TPM private key parser"
> - depends on ASYMMETRIC_TPM_KEY_SUBTYPE
> - select ASN1
> - help
> - This option provides support for parsing TPM format blobs for
> - private key data and provides the ability to instantiate a crypto key
> - from that data.
> -
> config PKCS7_MESSAGE_PARSER
> tristate "PKCS#7 message parser"
> depends on X509_CERTIFICATE_PARSER
> diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
> index 28b91adba2aed..c38424f55b08d 100644
> --- a/crypto/asymmetric_keys/Makefile
> +++ b/crypto/asymmetric_keys/Makefile
> @@ -11,7 +11,6 @@ asymmetric_keys-y := \
> signature.o
>
> obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
> -obj-$(CONFIG_ASYMMETRIC_TPM_KEY_SUBTYPE) += asym_tpm.o
>
> #
> # X.509 Certificate handling
> @@ -75,14 +74,3 @@ verify_signed_pefile-y := \
>
> $(obj)/mscode_parser.o: $(obj)/mscode.asn1.h $(obj)/mscode.asn1.h
> $(obj)/mscode.asn1.o: $(obj)/mscode.asn1.c $(obj)/mscode.asn1.h
> -
> -#
> -# TPM private key parsing
> -#
> -obj-$(CONFIG_TPM_KEY_PARSER) += tpm_key_parser.o
> -tpm_key_parser-y := \
> - tpm.asn1.o \
> - tpm_parser.o
> -
> -$(obj)/tpm_parser.o: $(obj)/tpm.asn1.h
> -$(obj)/tpm.asn1.o: $(obj)/tpm.asn1.c $(obj)/tpm.asn1.h
> diff --git a/crypto/asymmetric_keys/asym_tpm.c b/crypto/asymmetric_keys/asym_tpm.c
> deleted file mode 100644
> index 0959613560b9e..0000000000000
> --- a/crypto/asymmetric_keys/asym_tpm.c
> +++ /dev/null
> @@ -1,957 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#define pr_fmt(fmt) "ASYM-TPM: "fmt
> -#include <linux/slab.h>
> -#include <linux/module.h>
> -#include <linux/export.h>
> -#include <linux/kernel.h>
> -#include <linux/seq_file.h>
> -#include <linux/scatterlist.h>
> -#include <linux/tpm.h>
> -#include <linux/tpm_command.h>
> -#include <crypto/akcipher.h>
> -#include <crypto/hash.h>
> -#include <crypto/sha1.h>
> -#include <asm/unaligned.h>
> -#include <keys/asymmetric-subtype.h>
> -#include <keys/trusted_tpm.h>
> -#include <crypto/asym_tpm_subtype.h>
> -#include <crypto/public_key.h>
> -
> -#define TPM_ORD_FLUSHSPECIFIC 186
> -#define TPM_ORD_LOADKEY2 65
> -#define TPM_ORD_UNBIND 30
> -#define TPM_ORD_SIGN 60
> -
> -#define TPM_RT_KEY 0x00000001
> -
> -/*
> - * 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("oiap failed (%d)\n", ret);
> - return ret;
> - }
> -
> - /* generate odd nonce */
> - ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
> - if (ret < 0) {
> - pr_info("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 */
> - tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_LOADKEY2);
> - tpm_buf_append_u32(tb, keyhandle);
> - tpm_buf_append(tb, keyblob, keybloblen);
> - tpm_buf_append_u32(tb, authhandle);
> - tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
> - tpm_buf_append_u8(tb, cont);
> - tpm_buf_append(tb, authdata, SHA1_DIGEST_SIZE);
> -
> - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
> - if (ret < 0) {
> - pr_info("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("TSS_checkhmac1 failed (%d)\n", ret);
> - return ret;
> - }
> -
> - *newhandle = LOAD32(tb->data, TPM_DATA_OFFSET);
> - return 0;
> -}
> -
> -/*
> - * Execute the FlushSpecific TPM command
> - */
> -static int tpm_flushspecific(struct tpm_buf *tb, uint32_t handle)
> -{
> - tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_FLUSHSPECIFIC);
> - tpm_buf_append_u32(tb, handle);
> - tpm_buf_append_u32(tb, TPM_RT_KEY);
> -
> - return trusted_tpm_send(tb->data, MAX_BUF_SIZE);
> -}
> -
> -/*
> - * Decrypt a blob provided by userspace using a specific key handle.
> - * The handle is a well known handle or previously loaded by e.g. LoadKey2
> - */
> -static int tpm_unbind(struct tpm_buf *tb,
> - uint32_t keyhandle, unsigned char *keyauth,
> - const unsigned char *blob, uint32_t bloblen,
> - void *out, uint32_t outlen)
> -{
> - 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;
> - uint32_t datalen;
> - int ret;
> -
> - ordinal = htonl(TPM_ORD_UNBIND);
> - datalen = htonl(bloblen);
> -
> - /* session for loading the key */
> - ret = oiap(tb, &authhandle, enonce);
> - if (ret < 0) {
> - pr_info("oiap failed (%d)\n", ret);
> - return ret;
> - }
> -
> - /* generate odd nonce */
> - ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
> - if (ret < 0) {
> - pr_info("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,
> - sizeof(uint32_t), &datalen,
> - bloblen, blob, 0, 0);
> - if (ret < 0)
> - return ret;
> -
> - /* build the request buffer */
> - tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_UNBIND);
> - tpm_buf_append_u32(tb, keyhandle);
> - tpm_buf_append_u32(tb, bloblen);
> - tpm_buf_append(tb, blob, bloblen);
> - tpm_buf_append_u32(tb, authhandle);
> - tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
> - tpm_buf_append_u8(tb, cont);
> - tpm_buf_append(tb, authdata, SHA1_DIGEST_SIZE);
> -
> - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
> - if (ret < 0) {
> - pr_info("authhmac failed (%d)\n", ret);
> - return ret;
> - }
> -
> - datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
> -
> - ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
> - keyauth, SHA1_DIGEST_SIZE,
> - sizeof(uint32_t), TPM_DATA_OFFSET,
> - datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
> - 0, 0);
> - if (ret < 0) {
> - pr_info("TSS_checkhmac1 failed (%d)\n", ret);
> - return ret;
> - }
> -
> - memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
> - min(outlen, datalen));
> -
> - return datalen;
> -}
> -
> -/*
> - * Sign a blob provided by userspace (that has had the hash function applied)
> - * using a specific key handle. The handle is assumed to have been previously
> - * loaded by e.g. LoadKey2.
> - *
> - * Note that the key signature scheme of the used key should be set to
> - * TPM_SS_RSASSAPKCS1v15_DER. This allows the hashed input to be of any size
> - * up to key_length_in_bytes - 11 and not be limited to size 20 like the
> - * TPM_SS_RSASSAPKCS1v15_SHA1 signature scheme.
> - */
> -static int tpm_sign(struct tpm_buf *tb,
> - uint32_t keyhandle, unsigned char *keyauth,
> - const unsigned char *blob, uint32_t bloblen,
> - void *out, uint32_t outlen)
> -{
> - 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;
> - uint32_t datalen;
> - int ret;
> -
> - ordinal = htonl(TPM_ORD_SIGN);
> - datalen = htonl(bloblen);
> -
> - /* session for loading the key */
> - ret = oiap(tb, &authhandle, enonce);
> - if (ret < 0) {
> - pr_info("oiap failed (%d)\n", ret);
> - return ret;
> - }
> -
> - /* generate odd nonce */
> - ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
> - if (ret < 0) {
> - pr_info("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,
> - sizeof(uint32_t), &datalen,
> - bloblen, blob, 0, 0);
> - if (ret < 0)
> - return ret;
> -
> - /* build the request buffer */
> - tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SIGN);
> - tpm_buf_append_u32(tb, keyhandle);
> - tpm_buf_append_u32(tb, bloblen);
> - tpm_buf_append(tb, blob, bloblen);
> - tpm_buf_append_u32(tb, authhandle);
> - tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
> - tpm_buf_append_u8(tb, cont);
> - tpm_buf_append(tb, authdata, SHA1_DIGEST_SIZE);
> -
> - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
> - if (ret < 0) {
> - pr_info("authhmac failed (%d)\n", ret);
> - return ret;
> - }
> -
> - datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
> -
> - ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
> - keyauth, SHA1_DIGEST_SIZE,
> - sizeof(uint32_t), TPM_DATA_OFFSET,
> - datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
> - 0, 0);
> - if (ret < 0) {
> - pr_info("TSS_checkhmac1 failed (%d)\n", ret);
> - return ret;
> - }
> -
> - memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
> - min(datalen, outlen));
> -
> - return datalen;
> -}
> -
> -/* Room to fit two u32 zeros for algo id and parameters length. */
> -#define SETKEY_PARAMS_SIZE (sizeof(u32) * 2)
> -
> -/*
> - * Maximum buffer size for the BER/DER encoded public key. The public key
> - * is of the form SEQUENCE { INTEGER n, INTEGER e } where n is a maximum 2048
> - * bit key and e is usually 65537
> - * The encoding overhead is:
> - * - max 4 bytes for SEQUENCE
> - * - max 4 bytes for INTEGER n type/length
> - * - 257 bytes of n
> - * - max 2 bytes for INTEGER e type/length
> - * - 3 bytes of e
> - * - 4+4 of zeros for set_pub_key parameters (SETKEY_PARAMS_SIZE)
> - */
> -#define PUB_KEY_BUF_SIZE (4 + 4 + 257 + 2 + 3 + SETKEY_PARAMS_SIZE)
> -
> -/*
> - * Provide a part of a description of the key for /proc/keys.
> - */
> -static void asym_tpm_describe(const struct key *asymmetric_key,
> - struct seq_file *m)
> -{
> - struct tpm_key *tk = asymmetric_key->payload.data[asym_crypto];
> -
> - if (!tk)
> - return;
> -
> - seq_printf(m, "TPM1.2/Blob");
> -}
> -
> -static void asym_tpm_destroy(void *payload0, void *payload3)
> -{
> - struct tpm_key *tk = payload0;
> -
> - if (!tk)
> - return;
> -
> - kfree(tk->blob);
> - tk->blob_len = 0;
> -
> - kfree(tk);
> -}
> -
> -/* How many bytes will it take to encode the length */
> -static inline uint32_t definite_length(uint32_t len)
> -{
> - if (len <= 127)
> - return 1;
> - if (len <= 255)
> - return 2;
> - return 3;
> -}
> -
> -static inline uint8_t *encode_tag_length(uint8_t *buf, uint8_t tag,
> - uint32_t len)
> -{
> - *buf++ = tag;
> -
> - if (len <= 127) {
> - buf[0] = len;
> - return buf + 1;
> - }
> -
> - if (len <= 255) {
> - buf[0] = 0x81;
> - buf[1] = len;
> - return buf + 2;
> - }
> -
> - buf[0] = 0x82;
> - put_unaligned_be16(len, buf + 1);
> - return buf + 3;
> -}
> -
> -static uint32_t derive_pub_key(const void *pub_key, uint32_t len, uint8_t *buf)
> -{
> - uint8_t *cur = buf;
> - uint32_t n_len = definite_length(len) + 1 + len + 1;
> - uint32_t e_len = definite_length(3) + 1 + 3;
> - uint8_t e[3] = { 0x01, 0x00, 0x01 };
> -
> - /* SEQUENCE */
> - cur = encode_tag_length(cur, 0x30, n_len + e_len);
> - /* INTEGER n */
> - cur = encode_tag_length(cur, 0x02, len + 1);
> - cur[0] = 0x00;
> - memcpy(cur + 1, pub_key, len);
> - cur += len + 1;
> - cur = encode_tag_length(cur, 0x02, sizeof(e));
> - memcpy(cur, e, sizeof(e));
> - cur += sizeof(e);
> - /* Zero parameters to satisfy set_pub_key ABI. */
> - memzero_explicit(cur, SETKEY_PARAMS_SIZE);
> -
> - return cur - buf;
> -}
> -
> -/*
> - * Determine the crypto algorithm name.
> - */
> -static int determine_akcipher(const char *encoding, const char *hash_algo,
> - char alg_name[CRYPTO_MAX_ALG_NAME])
> -{
> - if (strcmp(encoding, "pkcs1") == 0) {
> - if (!hash_algo) {
> - strcpy(alg_name, "pkcs1pad(rsa)");
> - return 0;
> - }
> -
> - if (snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "pkcs1pad(rsa,%s)",
> - hash_algo) >= CRYPTO_MAX_ALG_NAME)
> - return -EINVAL;
> -
> - return 0;
> - }
> -
> - if (strcmp(encoding, "raw") == 0) {
> - strcpy(alg_name, "rsa");
> - return 0;
> - }
> -
> - return -ENOPKG;
> -}
> -
> -/*
> - * Query information about a key.
> - */
> -static int tpm_key_query(const struct kernel_pkey_params *params,
> - struct kernel_pkey_query *info)
> -{
> - struct tpm_key *tk = params->key->payload.data[asym_crypto];
> - int ret;
> - char alg_name[CRYPTO_MAX_ALG_NAME];
> - struct crypto_akcipher *tfm;
> - uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
> - uint32_t der_pub_key_len;
> - int len;
> -
> - /* TPM only works on private keys, public keys still done in software */
> - ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
> - if (ret < 0)
> - return ret;
> -
> - tfm = crypto_alloc_akcipher(alg_name, 0, 0);
> - if (IS_ERR(tfm))
> - return PTR_ERR(tfm);
> -
> - der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
> - der_pub_key);
> -
> - ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
> - if (ret < 0)
> - goto error_free_tfm;
> -
> - len = crypto_akcipher_maxsize(tfm);
> -
> - info->key_size = tk->key_len;
> - info->max_data_size = tk->key_len / 8;
> - info->max_sig_size = len;
> - info->max_enc_size = len;
> - info->max_dec_size = tk->key_len / 8;
> -
> - info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT |
> - KEYCTL_SUPPORTS_DECRYPT |
> - KEYCTL_SUPPORTS_VERIFY |
> - KEYCTL_SUPPORTS_SIGN;
> -
> - ret = 0;
> -error_free_tfm:
> - crypto_free_akcipher(tfm);
> - pr_devel("<==%s() = %d\n", __func__, ret);
> - return ret;
> -}
> -
> -/*
> - * Encryption operation is performed with the public key. Hence it is done
> - * in software
> - */
> -static int tpm_key_encrypt(struct tpm_key *tk,
> - struct kernel_pkey_params *params,
> - const void *in, void *out)
> -{
> - char alg_name[CRYPTO_MAX_ALG_NAME];
> - struct crypto_akcipher *tfm;
> - struct akcipher_request *req;
> - struct crypto_wait cwait;
> - struct scatterlist in_sg, out_sg;
> - uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
> - uint32_t der_pub_key_len;
> - int ret;
> -
> - pr_devel("==>%s()\n", __func__);
> -
> - ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
> - if (ret < 0)
> - return ret;
> -
> - tfm = crypto_alloc_akcipher(alg_name, 0, 0);
> - if (IS_ERR(tfm))
> - return PTR_ERR(tfm);
> -
> - der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
> - der_pub_key);
> -
> - ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
> - if (ret < 0)
> - goto error_free_tfm;
> -
> - ret = -ENOMEM;
> - req = akcipher_request_alloc(tfm, GFP_KERNEL);
> - if (!req)
> - goto error_free_tfm;
> -
> - sg_init_one(&in_sg, in, params->in_len);
> - sg_init_one(&out_sg, out, params->out_len);
> - akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
> - params->out_len);
> - crypto_init_wait(&cwait);
> - akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
> - CRYPTO_TFM_REQ_MAY_SLEEP,
> - crypto_req_done, &cwait);
> -
> - ret = crypto_akcipher_encrypt(req);
> - ret = crypto_wait_req(ret, &cwait);
> -
> - if (ret == 0)
> - ret = req->dst_len;
> -
> - akcipher_request_free(req);
> -error_free_tfm:
> - crypto_free_akcipher(tfm);
> - pr_devel("<==%s() = %d\n", __func__, ret);
> - return ret;
> -}
> -
> -/*
> - * Decryption operation is performed with the private key in the TPM.
> - */
> -static int tpm_key_decrypt(struct tpm_key *tk,
> - struct kernel_pkey_params *params,
> - const void *in, void *out)
> -{
> - struct tpm_buf tb;
> - uint32_t keyhandle;
> - uint8_t srkauth[SHA1_DIGEST_SIZE];
> - uint8_t keyauth[SHA1_DIGEST_SIZE];
> - int r;
> -
> - pr_devel("==>%s()\n", __func__);
> -
> - if (params->hash_algo)
> - return -ENOPKG;
> -
> - if (strcmp(params->encoding, "pkcs1"))
> - return -ENOPKG;
> -
> - r = tpm_buf_init(&tb, 0, 0);
> - if (r)
> - return r;
> -
> - /* TODO: Handle a non-all zero SRK authorization */
> - memset(srkauth, 0, sizeof(srkauth));
> -
> - r = tpm_loadkey2(&tb, SRKHANDLE, srkauth,
> - tk->blob, tk->blob_len, &keyhandle);
> - if (r < 0) {
> - pr_devel("loadkey2 failed (%d)\n", r);
> - goto error;
> - }
> -
> - /* TODO: Handle a non-all zero key authorization */
> - memset(keyauth, 0, sizeof(keyauth));
> -
> - r = tpm_unbind(&tb, keyhandle, keyauth,
> - in, params->in_len, out, params->out_len);
> - if (r < 0)
> - pr_devel("tpm_unbind failed (%d)\n", r);
> -
> - if (tpm_flushspecific(&tb, keyhandle) < 0)
> - pr_devel("flushspecific failed (%d)\n", r);
> -
> -error:
> - tpm_buf_destroy(&tb);
> - pr_devel("<==%s() = %d\n", __func__, r);
> - return r;
> -}
> -
> -/*
> - * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
> - */
> -static const u8 digest_info_md5[] = {
> - 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
> - 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
> - 0x05, 0x00, 0x04, 0x10
> -};
> -
> -static const u8 digest_info_sha1[] = {
> - 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
> - 0x2b, 0x0e, 0x03, 0x02, 0x1a,
> - 0x05, 0x00, 0x04, 0x14
> -};
> -
> -static const u8 digest_info_rmd160[] = {
> - 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
> - 0x2b, 0x24, 0x03, 0x02, 0x01,
> - 0x05, 0x00, 0x04, 0x14
> -};
> -
> -static const u8 digest_info_sha224[] = {
> - 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
> - 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
> - 0x05, 0x00, 0x04, 0x1c
> -};
> -
> -static const u8 digest_info_sha256[] = {
> - 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
> - 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
> - 0x05, 0x00, 0x04, 0x20
> -};
> -
> -static const u8 digest_info_sha384[] = {
> - 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
> - 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
> - 0x05, 0x00, 0x04, 0x30
> -};
> -
> -static const u8 digest_info_sha512[] = {
> - 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
> - 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
> - 0x05, 0x00, 0x04, 0x40
> -};
> -
> -static const struct asn1_template {
> - const char *name;
> - const u8 *data;
> - size_t size;
> -} asn1_templates[] = {
> -#define _(X) { #X, digest_info_##X, sizeof(digest_info_##X) }
> - _(md5),
> - _(sha1),
> - _(rmd160),
> - _(sha256),
> - _(sha384),
> - _(sha512),
> - _(sha224),
> - { NULL }
> -#undef _
> -};
> -
> -static const struct asn1_template *lookup_asn1(const char *name)
> -{
> - const struct asn1_template *p;
> -
> - for (p = asn1_templates; p->name; p++)
> - if (strcmp(name, p->name) == 0)
> - return p;
> - return NULL;
> -}
> -
> -/*
> - * Sign operation is performed with the private key in the TPM.
> - */
> -static int tpm_key_sign(struct tpm_key *tk,
> - struct kernel_pkey_params *params,
> - const void *in, void *out)
> -{
> - struct tpm_buf tb;
> - uint32_t keyhandle;
> - uint8_t srkauth[SHA1_DIGEST_SIZE];
> - uint8_t keyauth[SHA1_DIGEST_SIZE];
> - void *asn1_wrapped = NULL;
> - uint32_t in_len = params->in_len;
> - int r;
> -
> - pr_devel("==>%s()\n", __func__);
> -
> - if (strcmp(params->encoding, "pkcs1"))
> - return -ENOPKG;
> -
> - if (params->hash_algo) {
> - const struct asn1_template *asn1 =
> - lookup_asn1(params->hash_algo);
> -
> - if (!asn1)
> - return -ENOPKG;
> -
> - /* request enough space for the ASN.1 template + input hash */
> - asn1_wrapped = kzalloc(in_len + asn1->size, GFP_KERNEL);
> - if (!asn1_wrapped)
> - return -ENOMEM;
> -
> - /* Copy ASN.1 template, then the input */
> - memcpy(asn1_wrapped, asn1->data, asn1->size);
> - memcpy(asn1_wrapped + asn1->size, in, in_len);
> -
> - in = asn1_wrapped;
> - in_len += asn1->size;
> - }
> -
> - if (in_len > tk->key_len / 8 - 11) {
> - r = -EOVERFLOW;
> - goto error_free_asn1_wrapped;
> - }
> -
> - r = tpm_buf_init(&tb, 0, 0);
> - if (r)
> - goto error_free_asn1_wrapped;
> -
> - /* TODO: Handle a non-all zero SRK authorization */
> - memset(srkauth, 0, sizeof(srkauth));
> -
> - r = tpm_loadkey2(&tb, SRKHANDLE, srkauth,
> - tk->blob, tk->blob_len, &keyhandle);
> - if (r < 0) {
> - pr_devel("loadkey2 failed (%d)\n", r);
> - goto error_free_tb;
> - }
> -
> - /* TODO: Handle a non-all zero key authorization */
> - memset(keyauth, 0, sizeof(keyauth));
> -
> - r = tpm_sign(&tb, keyhandle, keyauth, in, in_len, out, params->out_len);
> - if (r < 0)
> - pr_devel("tpm_sign failed (%d)\n", r);
> -
> - if (tpm_flushspecific(&tb, keyhandle) < 0)
> - pr_devel("flushspecific failed (%d)\n", r);
> -
> -error_free_tb:
> - tpm_buf_destroy(&tb);
> -error_free_asn1_wrapped:
> - kfree(asn1_wrapped);
> - pr_devel("<==%s() = %d\n", __func__, r);
> - return r;
> -}
> -
> -/*
> - * Do encryption, decryption and signing ops.
> - */
> -static int tpm_key_eds_op(struct kernel_pkey_params *params,
> - const void *in, void *out)
> -{
> - struct tpm_key *tk = params->key->payload.data[asym_crypto];
> - int ret = -EOPNOTSUPP;
> -
> - /* Perform the encryption calculation. */
> - switch (params->op) {
> - case kernel_pkey_encrypt:
> - ret = tpm_key_encrypt(tk, params, in, out);
> - break;
> - case kernel_pkey_decrypt:
> - ret = tpm_key_decrypt(tk, params, in, out);
> - break;
> - case kernel_pkey_sign:
> - ret = tpm_key_sign(tk, params, in, out);
> - break;
> - default:
> - BUG();
> - }
> -
> - return ret;
> -}
> -
> -/*
> - * Verify a signature using a public key.
> - */
> -static int tpm_key_verify_signature(const struct key *key,
> - const struct public_key_signature *sig)
> -{
> - const struct tpm_key *tk = key->payload.data[asym_crypto];
> - struct crypto_wait cwait;
> - struct crypto_akcipher *tfm;
> - struct akcipher_request *req;
> - struct scatterlist src_sg[2];
> - char alg_name[CRYPTO_MAX_ALG_NAME];
> - uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
> - uint32_t der_pub_key_len;
> - int ret;
> -
> - pr_devel("==>%s()\n", __func__);
> -
> - BUG_ON(!tk);
> - BUG_ON(!sig);
> - BUG_ON(!sig->s);
> -
> - if (!sig->digest)
> - return -ENOPKG;
> -
> - ret = determine_akcipher(sig->encoding, sig->hash_algo, alg_name);
> - if (ret < 0)
> - return ret;
> -
> - tfm = crypto_alloc_akcipher(alg_name, 0, 0);
> - if (IS_ERR(tfm))
> - return PTR_ERR(tfm);
> -
> - der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
> - der_pub_key);
> -
> - ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
> - if (ret < 0)
> - goto error_free_tfm;
> -
> - ret = -ENOMEM;
> - req = akcipher_request_alloc(tfm, GFP_KERNEL);
> - if (!req)
> - goto error_free_tfm;
> -
> - sg_init_table(src_sg, 2);
> - sg_set_buf(&src_sg[0], sig->s, sig->s_size);
> - sg_set_buf(&src_sg[1], sig->digest, sig->digest_size);
> - akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size,
> - sig->digest_size);
> - crypto_init_wait(&cwait);
> - akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
> - CRYPTO_TFM_REQ_MAY_SLEEP,
> - crypto_req_done, &cwait);
> - ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
> -
> - akcipher_request_free(req);
> -error_free_tfm:
> - crypto_free_akcipher(tfm);
> - pr_devel("<==%s() = %d\n", __func__, ret);
> - if (WARN_ON_ONCE(ret > 0))
> - ret = -EINVAL;
> - return ret;
> -}
> -
> -/*
> - * Parse enough information out of TPM_KEY structure:
> - * TPM_STRUCT_VER -> 4 bytes
> - * TPM_KEY_USAGE -> 2 bytes
> - * TPM_KEY_FLAGS -> 4 bytes
> - * TPM_AUTH_DATA_USAGE -> 1 byte
> - * TPM_KEY_PARMS -> variable
> - * UINT32 PCRInfoSize -> 4 bytes
> - * BYTE* -> PCRInfoSize bytes
> - * TPM_STORE_PUBKEY
> - * UINT32 encDataSize;
> - * BYTE* -> encDataSize;
> - *
> - * TPM_KEY_PARMS:
> - * TPM_ALGORITHM_ID -> 4 bytes
> - * TPM_ENC_SCHEME -> 2 bytes
> - * TPM_SIG_SCHEME -> 2 bytes
> - * UINT32 parmSize -> 4 bytes
> - * BYTE* -> variable
> - */
> -static int extract_key_parameters(struct tpm_key *tk)
> -{
> - const void *cur = tk->blob;
> - uint32_t len = tk->blob_len;
> - const void *pub_key;
> - uint32_t sz;
> - uint32_t key_len;
> -
> - if (len < 11)
> - return -EBADMSG;
> -
> - /* Ensure this is a legacy key */
> - if (get_unaligned_be16(cur + 4) != 0x0015)
> - return -EBADMSG;
> -
> - /* Skip to TPM_KEY_PARMS */
> - cur += 11;
> - len -= 11;
> -
> - if (len < 12)
> - return -EBADMSG;
> -
> - /* Make sure this is an RSA key */
> - if (get_unaligned_be32(cur) != 0x00000001)
> - return -EBADMSG;
> -
> - /* Make sure this is TPM_ES_RSAESPKCSv15 encoding scheme */
> - if (get_unaligned_be16(cur + 4) != 0x0002)
> - return -EBADMSG;
> -
> - /* Make sure this is TPM_SS_RSASSAPKCS1v15_DER signature scheme */
> - if (get_unaligned_be16(cur + 6) != 0x0003)
> - return -EBADMSG;
> -
> - sz = get_unaligned_be32(cur + 8);
> - if (len < sz + 12)
> - return -EBADMSG;
> -
> - /* Move to TPM_RSA_KEY_PARMS */
> - len -= 12;
> - cur += 12;
> -
> - /* Grab the RSA key length */
> - key_len = get_unaligned_be32(cur);
> -
> - switch (key_len) {
> - case 512:
> - case 1024:
> - case 1536:
> - case 2048:
> - break;
> - default:
> - return -EINVAL;
> - }
> -
> - /* Move just past TPM_KEY_PARMS */
> - cur += sz;
> - len -= sz;
> -
> - if (len < 4)
> - return -EBADMSG;
> -
> - sz = get_unaligned_be32(cur);
> - if (len < 4 + sz)
> - return -EBADMSG;
> -
> - /* Move to TPM_STORE_PUBKEY */
> - cur += 4 + sz;
> - len -= 4 + sz;
> -
> - /* Grab the size of the public key, it should jive with the key size */
> - sz = get_unaligned_be32(cur);
> - if (sz > 256)
> - return -EINVAL;
> -
> - pub_key = cur + 4;
> -
> - tk->key_len = key_len;
> - tk->pub_key = pub_key;
> - tk->pub_key_len = sz;
> -
> - return 0;
> -}
> -
> -/* Given the blob, parse it and load it into the TPM */
> -struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len)
> -{
> - int r;
> - struct tpm_key *tk;
> -
> - r = tpm_is_tpm2(NULL);
> - if (r < 0)
> - goto error;
> -
> - /* We don't support TPM2 yet */
> - if (r > 0) {
> - r = -ENODEV;
> - goto error;
> - }
> -
> - r = -ENOMEM;
> - tk = kzalloc(sizeof(struct tpm_key), GFP_KERNEL);
> - if (!tk)
> - goto error;
> -
> - tk->blob = kmemdup(blob, blob_len, GFP_KERNEL);
> - if (!tk->blob)
> - goto error_memdup;
> -
> - tk->blob_len = blob_len;
> -
> - r = extract_key_parameters(tk);
> - if (r < 0)
> - goto error_extract;
> -
> - return tk;
> -
> -error_extract:
> - kfree(tk->blob);
> - tk->blob_len = 0;
> -error_memdup:
> - kfree(tk);
> -error:
> - return ERR_PTR(r);
> -}
> -EXPORT_SYMBOL_GPL(tpm_key_create);
> -
> -/*
> - * TPM-based asymmetric key subtype
> - */
> -struct asymmetric_key_subtype asym_tpm_subtype = {
> - .owner = THIS_MODULE,
> - .name = "asym_tpm",
> - .name_len = sizeof("asym_tpm") - 1,
> - .describe = asym_tpm_describe,
> - .destroy = asym_tpm_destroy,
> - .query = tpm_key_query,
> - .eds_op = tpm_key_eds_op,
> - .verify_signature = tpm_key_verify_signature,
> -};
> -EXPORT_SYMBOL_GPL(asym_tpm_subtype);
> -
> -MODULE_DESCRIPTION("TPM based asymmetric key subtype");
> -MODULE_AUTHOR("Intel Corporation");
> -MODULE_LICENSE("GPL v2");
> diff --git a/crypto/asymmetric_keys/tpm.asn1 b/crypto/asymmetric_keys/tpm.asn1
> deleted file mode 100644
> index d7f194232f30a..0000000000000
> --- a/crypto/asymmetric_keys/tpm.asn1
> +++ /dev/null
> @@ -1,5 +0,0 @@
> ---
> --- Unencryted TPM Blob. For details of the format, see:
> --- http://david.woodhou.se/draft-woodhouse-cert-best-practice.html#I-D.mavrogiannopoulos-tpmuri
> ---
> -PrivateKeyInfo ::= OCTET STRING ({ tpm_note_key })
> diff --git a/crypto/asymmetric_keys/tpm_parser.c b/crypto/asymmetric_keys/tpm_parser.c
> deleted file mode 100644
> index 96405d8dcd98d..0000000000000
> --- a/crypto/asymmetric_keys/tpm_parser.c
> +++ /dev/null
> @@ -1,102 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#define pr_fmt(fmt) "TPM-PARSER: "fmt
> -#include <linux/module.h>
> -#include <linux/kernel.h>
> -#include <linux/export.h>
> -#include <linux/slab.h>
> -#include <linux/err.h>
> -#include <keys/asymmetric-subtype.h>
> -#include <keys/asymmetric-parser.h>
> -#include <crypto/asym_tpm_subtype.h>
> -#include "tpm.asn1.h"
> -
> -struct tpm_parse_context {
> - const void *blob;
> - u32 blob_len;
> -};
> -
> -/*
> - * Note the key data of the ASN.1 blob.
> - */
> -int tpm_note_key(void *context, size_t hdrlen,
> - unsigned char tag,
> - const void *value, size_t vlen)
> -{
> - struct tpm_parse_context *ctx = context;
> -
> - ctx->blob = value;
> - ctx->blob_len = vlen;
> -
> - return 0;
> -}
> -
> -/*
> - * Parse a TPM-encrypted private key blob.
> - */
> -static struct tpm_key *tpm_parse(const void *data, size_t datalen)
> -{
> - struct tpm_parse_context ctx;
> - long ret;
> -
> - memset(&ctx, 0, sizeof(ctx));
> -
> - /* Attempt to decode the private key */
> - ret = asn1_ber_decoder(&tpm_decoder, &ctx, data, datalen);
> - if (ret < 0)
> - goto error;
> -
> - return tpm_key_create(ctx.blob, ctx.blob_len);
> -
> -error:
> - return ERR_PTR(ret);
> -}
> -/*
> - * Attempt to parse a data blob for a key as a TPM private key blob.
> - */
> -static int tpm_key_preparse(struct key_preparsed_payload *prep)
> -{
> - struct tpm_key *tk;
> -
> - /*
> - * TPM 1.2 keys are max 2048 bits long, so assume the blob is no
> - * more than 4x that
> - */
> - if (prep->datalen > 256 * 4)
> - return -EMSGSIZE;
> -
> - tk = tpm_parse(prep->data, prep->datalen);
> -
> - if (IS_ERR(tk))
> - return PTR_ERR(tk);
> -
> - /* We're pinning the module by being linked against it */
> - __module_get(asym_tpm_subtype.owner);
> - prep->payload.data[asym_subtype] = &asym_tpm_subtype;
> - prep->payload.data[asym_key_ids] = NULL;
> - prep->payload.data[asym_crypto] = tk;
> - prep->payload.data[asym_auth] = NULL;
> - prep->quotalen = 100;
> - return 0;
> -}
> -
> -static struct asymmetric_key_parser tpm_key_parser = {
> - .owner = THIS_MODULE,
> - .name = "tpm_parser",
> - .parse = tpm_key_preparse,
> -};
> -
> -static int __init tpm_key_init(void)
> -{
> - return register_asymmetric_key_parser(&tpm_key_parser);
> -}
> -
> -static void __exit tpm_key_exit(void)
> -{
> - unregister_asymmetric_key_parser(&tpm_key_parser);
> -}
> -
> -module_init(tpm_key_init);
> -module_exit(tpm_key_exit);
> -
> -MODULE_DESCRIPTION("TPM private key-blob parser");
> -MODULE_LICENSE("GPL v2");
> diff --git a/include/crypto/asym_tpm_subtype.h b/include/crypto/asym_tpm_subtype.h
> deleted file mode 100644
> index 48198c36d6b9b..0000000000000
> --- a/include/crypto/asym_tpm_subtype.h
> +++ /dev/null
> @@ -1,19 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#ifndef _LINUX_ASYM_TPM_SUBTYPE_H
> -#define _LINUX_ASYM_TPM_SUBTYPE_H
> -
> -#include <linux/keyctl.h>
> -
> -struct tpm_key {
> - void *blob;
> - u32 blob_len;
> - uint16_t key_len; /* Size in bits of the key */
> - const void *pub_key; /* pointer inside blob to the public key bytes */
> - uint16_t pub_key_len; /* length of the public key */
> -};
> -
> -struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len);
> -
> -extern struct asymmetric_key_subtype asym_tpm_subtype;
> -
> -#endif /* _LINUX_ASYM_TPM_SUBTYPE_H */
> --
> 2.35.0
>
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
/Jarkko