Migrate tpm2_key_{encode,decode}() to TPM driver and export the symbols to make them callable from trusted keys.
Signed-off-by: Jarkko Sakkinen <jar...@kernel.org> --- drivers/char/tpm/Kconfig | 5 + drivers/char/tpm/Makefile | 5 + drivers/char/tpm/tpm2_key.c | 181 +++++++++++++++++ .../char/tpm}/tpm2key.asn1 | 0 include/crypto/tpm2_key.h | 33 ++++ security/keys/trusted-keys/Makefile | 2 - security/keys/trusted-keys/trusted_tpm2.c | 187 ++---------------- 7 files changed, 242 insertions(+), 171 deletions(-) create mode 100644 drivers/char/tpm/tpm2_key.c rename {security/keys/trusted-keys => drivers/char/tpm}/tpm2key.asn1 (100%) create mode 100644 include/crypto/tpm2_key.h diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index db41301e63f2..d5d06cc96932 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -3,10 +3,15 @@ # TPM device configuration # +config TCG_TPM2_KEY + bool + menuconfig TCG_TPM tristate "TPM Hardware Support" depends on HAS_IOMEM imply SECURITYFS + select ASN1 + select ASN1_ENCODER select CRYPTO select CRYPTO_HASH_INFO help diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index 4c695b0388f3..071437058ef6 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -17,6 +17,11 @@ tpm-y += eventlog/tpm1.o tpm-y += eventlog/tpm2.o tpm-y += tpm-buf.o +# TPM2 Asymmetric Key +$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h +tpm-y += tpm2key.asn1.o +tpm-y += tpm2_key.o + tpm-$(CONFIG_TCG_TPM2_HMAC) += tpm2-sessions.o tpm-$(CONFIG_ACPI) += tpm_ppi.o eventlog/acpi.o tpm-$(CONFIG_EFI) += eventlog/efi.o diff --git a/drivers/char/tpm/tpm2_key.c b/drivers/char/tpm/tpm2_key.c new file mode 100644 index 000000000000..e09441efb0f0 --- /dev/null +++ b/drivers/char/tpm/tpm2_key.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define pr_fmt(fmt) "tpm2_key: "fmt + +#include <linux/asn1_encoder.h> +#include <linux/asn1_decoder.h> +#include <linux/oid_registry.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <crypto/tpm2_key.h> +#include <asm/unaligned.h> +#include <keys/trusted-type.h> +#include "tpm2key.asn1.h" + +static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 }; + +int tpm2_key_parent(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key *ctx = context; + const u8 *v = value; + int i; + + ctx->parent = 0; + for (i = 0; i < vlen; i++) { + ctx->parent <<= 8; + ctx->parent |= v[i]; + } + + return 0; +} + +int tpm2_key_type(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + enum OID oid = look_up_OID(value, vlen); + + if (oid != OID_TPMSealedData) { + char buffer[50]; + + sprint_oid(value, vlen, buffer, sizeof(buffer)); + pr_debug("OID is \"%s\" which is not TPMSealedData\n", + buffer); + return -EINVAL; + } + + return 0; +} + +int tpm2_key_pub(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key *ctx = context; + + ctx->pub = value; + ctx->pub_len = vlen; + + return 0; +} + +int tpm2_key_priv(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct tpm2_key *ctx = context; + + ctx->priv = value; + ctx->priv_len = vlen; + + return 0; +} + +/** + * tpm2_key_encode() - Encode TPM2 ASN.1 key. + * @blob: Decoded blob. + * @blob_auth_len: Authorization length. + * @key_handle: TPM2 handle of the key. + * @src: ASN.1 source. + * + * Encodes TPM2 ASN.1 key on success. Returns POSIX error code on failure. + */ +int tpm2_key_encode(u8 *blob, u32 blob_auth_len, u32 key_handle, u8 *src) +{ + const int SCRATCH_SIZE = PAGE_SIZE; + u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL); + u8 *work = scratch, *work1; + u8 *end_work = scratch + SCRATCH_SIZE; + u8 *priv, *pub; + u16 priv_len, pub_len; + int ret; + + priv_len = get_unaligned_be16(src) + 2; + priv = src; + + src += priv_len; + + pub_len = get_unaligned_be16(src) + 2; + pub = src; + + if (!scratch) + return -ENOMEM; + + work = asn1_encode_oid(work, end_work, tpm2key_oid, + asn1_oid_len(tpm2key_oid)); + + if (blob_auth_len == 0) { + unsigned char bool[3], *w = bool; + /* tag 0 is emptyAuth */ + w = asn1_encode_boolean(w, w + sizeof(bool), true); + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) + return PTR_ERR(w); + work = asn1_encode_tag(work, end_work, 0, bool, w - bool); + } + + /* + * Assume both octet strings will encode to a 2 byte definite length + * + * Note: For a well behaved TPM, this warning should never + * trigger, so if it does there's something nefarious going on + */ + if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE, + "BUG: scratch buffer is too small")) + return -EINVAL; + + work = asn1_encode_integer(work, end_work, key_handle); + work = asn1_encode_octet_string(work, end_work, pub, pub_len); + work = asn1_encode_octet_string(work, end_work, priv, priv_len); + + work1 = blob; + work1 = asn1_encode_sequence(work1, work1 + MAX_BLOB_SIZE, scratch, work - scratch); + if (IS_ERR(work1)) { + ret = PTR_ERR(work1); + pr_err("ASN.1 encoder failed with %d\n", ret); + return ret; + } + + return work1 - blob; +} +EXPORT_SYMBOL_GPL(tpm2_key_encode); + +/** + * tpm_key_decode() - Decode TPM2 ASN.1 key. + * @src: ASN.1 source. + * @src_len: ASN.1 source length. + * @key: TPM2 asymmetric key. + * @max_key_len: Maximum length of the TPM2 asymmetric key. + * + * Decodes TPM2 ASN.1 key on success. Returns POSIX error code on failure. + */ +int tpm2_key_decode(const u8 *src, u32 src_len, struct tpm2_key *key, + u32 max_key_len) +{ + struct tpm2_key ctx; + int ret; + + memset(&ctx, 0, sizeof(ctx)); + + ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, src, src_len); + if (ret < 0) + return ret; + + if (ctx.priv_len + ctx.pub_len > max_key_len) + return -EINVAL; + + ctx.priv = kmemdup(ctx.priv, ctx.priv_len, GFP_KERNEL); + if (!ctx.priv) + return -ENOMEM; + + ctx.pub = kmemdup(ctx.pub, ctx.pub_len, GFP_KERNEL); + if (!ctx.pub) { + kfree(ctx.priv); + return -ENOMEM; + } + + memcpy(key, &ctx, sizeof(ctx)); + return 0; +} +EXPORT_SYMBOL_GPL(tpm2_key_decode); diff --git a/security/keys/trusted-keys/tpm2key.asn1 b/drivers/char/tpm/tpm2key.asn1 similarity index 100% rename from security/keys/trusted-keys/tpm2key.asn1 rename to drivers/char/tpm/tpm2key.asn1 diff --git a/include/crypto/tpm2_key.h b/include/crypto/tpm2_key.h new file mode 100644 index 000000000000..e5d3330afef5 --- /dev/null +++ b/include/crypto/tpm2_key.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __LINUX_TPM2_KEY_H__ +#define __LINUX_TPM2_KEY_H__ + +#include <linux/slab.h> + +/* + * TPM2 ASN.1 key + */ +struct tpm2_key { + u32 parent; + const u8 *pub; + u32 pub_len; + const u8 *priv; + u32 priv_len; +}; + +int tpm2_key_encode(u8 *blob, u32 blob_auth_len, u32 key_handle, u8 *src); +int tpm2_key_decode(const u8 *src, u32 src_len, struct tpm2_key *key, + u32 max_key_len); + +/** + * tpm2_key_free() - Release TPM2 asymmetric key resources and reset values + * @key: TPM2 asymmetric key. + */ +static inline void tpm2_key_destroy(struct tpm2_key *key) +{ + kfree(key->priv); + kfree(key->pub); + memset(key, 0, sizeof(*key)); +} + +#endif /* __LINUX_TPM2_KEY_H__ */ diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index f0f3b27f688b..2674d5c10fc9 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -7,9 +7,7 @@ obj-$(CONFIG_TRUSTED_KEYS) += trusted.o trusted-y += trusted_core.o trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o -$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o -trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index dbdd6a318b8b..3e1140914ca4 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -13,11 +13,10 @@ #include <keys/trusted-type.h> #include <keys/trusted_tpm.h> +#include <crypto/tpm2_key.h> #include <asm/unaligned.h> -#include "tpm2key.asn1.h" - static struct tpm2_hash tpm2_hash_map[] = { {HASH_ALGO_SHA1, TPM_ALG_SHA1}, {HASH_ALGO_SHA256, TPM_ALG_SHA256}, @@ -26,169 +25,6 @@ static struct tpm2_hash tpm2_hash_map[] = { {HASH_ALGO_SM3_256, TPM_ALG_SM3_256}, }; -static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 }; - -static int tpm2_key_encode(struct trusted_key_payload *payload, - struct trusted_key_options *options, - u8 *src, u32 len) -{ - const int SCRATCH_SIZE = PAGE_SIZE; - u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL); - u8 *work = scratch, *work1; - u8 *end_work = scratch + SCRATCH_SIZE; - u8 *priv, *pub; - u16 priv_len, pub_len; - int ret; - - priv_len = get_unaligned_be16(src) + 2; - priv = src; - - src += priv_len; - - pub_len = get_unaligned_be16(src) + 2; - pub = src; - - if (!scratch) - return -ENOMEM; - - work = asn1_encode_oid(work, end_work, tpm2key_oid, - asn1_oid_len(tpm2key_oid)); - - if (options->blobauth_len == 0) { - unsigned char bool[3], *w = bool; - /* tag 0 is emptyAuth */ - w = asn1_encode_boolean(w, w + sizeof(bool), true); - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) - return PTR_ERR(w); - work = asn1_encode_tag(work, end_work, 0, bool, w - bool); - } - - /* - * Assume both octet strings will encode to a 2 byte definite length - * - * Note: For a well behaved TPM, this warning should never - * trigger, so if it does there's something nefarious going on - */ - if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE, - "BUG: scratch buffer is too small")) - return -EINVAL; - - work = asn1_encode_integer(work, end_work, options->keyhandle); - work = asn1_encode_octet_string(work, end_work, pub, pub_len); - work = asn1_encode_octet_string(work, end_work, priv, priv_len); - - work1 = payload->blob; - work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob), - scratch, work - scratch); - if (IS_ERR(work1)) { - ret = PTR_ERR(work1); - pr_err("ASN.1 encode error %d\n", ret); - return ret; - } - - return work1 - payload->blob; -} - -struct tpm2_key_context { - u32 parent; - const u8 *pub; - u32 pub_len; - const u8 *priv; - u32 priv_len; -}; - -static int tpm2_key_decode(struct trusted_key_payload *payload, - struct trusted_key_options *options, - u8 **buf) -{ - int ret; - struct tpm2_key_context ctx; - u8 *blob; - - memset(&ctx, 0, sizeof(ctx)); - - ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, payload->blob, - payload->blob_len); - if (ret < 0) - return ret; - - if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE) - return -EINVAL; - - blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL); - if (!blob) - return -ENOMEM; - - *buf = blob; - options->keyhandle = ctx.parent; - - memcpy(blob, ctx.priv, ctx.priv_len); - blob += ctx.priv_len; - - memcpy(blob, ctx.pub, ctx.pub_len); - - return 0; -} - -int tpm2_key_parent(void *context, size_t hdrlen, - unsigned char tag, - const void *value, size_t vlen) -{ - struct tpm2_key_context *ctx = context; - const u8 *v = value; - int i; - - ctx->parent = 0; - for (i = 0; i < vlen; i++) { - ctx->parent <<= 8; - ctx->parent |= v[i]; - } - - return 0; -} - -int tpm2_key_type(void *context, size_t hdrlen, - unsigned char tag, - const void *value, size_t vlen) -{ - enum OID oid = look_up_OID(value, vlen); - - if (oid != OID_TPMSealedData) { - char buffer[50]; - - sprint_oid(value, vlen, buffer, sizeof(buffer)); - pr_debug("OID is \"%s\" which is not TPMSealedData\n", - buffer); - return -EINVAL; - } - - return 0; -} - -int tpm2_key_pub(void *context, size_t hdrlen, - unsigned char tag, - const void *value, size_t vlen) -{ - struct tpm2_key_context *ctx = context; - - ctx->pub = value; - ctx->pub_len = vlen; - - return 0; -} - -int tpm2_key_priv(void *context, size_t hdrlen, - unsigned char tag, - const void *value, size_t vlen) -{ - struct tpm2_key_context *ctx = context; - - ctx->priv = value; - ctx->priv_len = vlen; - - return 0; -} - /** * tpm2_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer. * @@ -338,7 +174,8 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out; } - blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len); + blob_len = tpm2_key_encode(payload->blob, options->blobauth_len, + options->keyhandle, &buf.data[offset]); out: tpm_buf_destroy(&sized); @@ -378,20 +215,32 @@ static int tpm2_load_cmd(struct tpm_chip *chip, struct trusted_key_options *options, u32 *blob_handle) { - struct tpm_buf buf; unsigned int private_len; unsigned int public_len; unsigned int blob_len; + struct tpm2_key key; + struct tpm_buf buf; u8 *blob, *pub; int rc; u32 attrs; - rc = tpm2_key_decode(payload, options, &blob); + rc = tpm2_key_decode(payload->blob, payload->blob_len, &key, + MAX_BLOB_SIZE); if (rc) { - /* old form */ + /* legacy format: */ blob = payload->blob; payload->old_format = 1; + } else { + blob = kmalloc(key.priv_len + key.pub_len + 4, GFP_KERNEL); + if (blob) { + options->keyhandle = key.parent; + memcpy(blob, key.priv, key.priv_len); + memcpy(&blob[key.priv_len], key.pub, key.pub_len); + } } + tpm2_key_destroy(&key); + if (!blob) + return -ENOMEM; /* new format carries keyhandle but old format doesn't */ if (!options->keyhandle) -- 2.45.1