Re: [PATCH 1/2] tpm2-sessions: Add full HMAC and encrypt/decrypt session handling

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Fri, Mar 02, 2018 at 10:06:15PM -0800, James Bottomley wrote:
> diff --git a/drivers/char/tpm/tpm2b.h b/drivers/char/tpm/tpm2b.h
> new file mode 100644
> index 000000000000..c7726f2895aa
> --- /dev/null
> +++ b/drivers/char/tpm/tpm2b.h
> @@ -0,0 +1,82 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _TPM2_TPM2B_H
> +#define _TPM2_TPM2B_H
> +/*
> + * Handing for tpm2b structures to facilitate the building of commands
> + */
> +
> +#include "tpm.h"
> +
> +#include <asm/unaligned.h>
> +
> +struct tpm2b {
> +	struct tpm_buf buf;
> +};
> +
> +/* opaque structure, holds auth session parameters like the session key */
> +struct tpm2_auth;
> +
> +static inline int tpm2b_init(struct tpm2b *buf)
> +{
> +	return tpm_buf_init(&buf->buf, 0, 0);
> +}
> +
> +static inline void tpm2b_reset(struct tpm2b *buf)
> +{
> +	struct tpm_input_header *head;
> +
> +	head = (struct tpm_input_header *)buf->buf.data;
> +	head->length = cpu_to_be32(sizeof(*head));
> +}
> +
> +static inline void tpm2b_append(struct tpm2b *buf, const unsigned char *data,
> +				unsigned int len)
> +{
> +	tpm_buf_append(&buf->buf, data, len);
> +}
> +
> +#define TPM2B_APPEND(type) \
> +	static inline void tpm2b_append_##type(struct tpm2b *buf, const type value) { tpm_buf_append_##type(&buf->buf, value); }
> +
> +TPM2B_APPEND(u8)
> +TPM2B_APPEND(u16)
> +TPM2B_APPEND(u32)
> +
> +static inline void *tpm2b_buffer(const struct tpm2b *buf)
> +{
> +	return buf->buf.data + sizeof(struct tpm_input_header);
> +}
> +
> +static inline u16 tpm2b_len(struct tpm2b *buf)
> +{
> +	return tpm_buf_length(&buf->buf) - sizeof(struct tpm_input_header);
> +}
> +
> +static inline void tpm2b_destroy(struct tpm2b *buf)
> +{
> +	tpm_buf_destroy(&buf->buf);
> +}
> +
> +static inline void tpm_buf_append_2b(struct tpm_buf *buf, struct tpm2b *tpm2b)
> +{
> +	u16 len = tpm2b_len(tpm2b);
> +
> +	tpm_buf_append_u16(buf, len);
> +	tpm_buf_append(buf, tpm2b_buffer(tpm2b), len);
> +	/* clear the buf for reuse */
> +	tpm2b_reset(tpm2b);
> +}
> +
> +/* Macros for unmarshalling known size BE data */
> +#define GET_INC(type)					\
> +static inline u##type get_inc_##type(const u8 **ptr) {	\
> +	u##type val;					\
> +	val = get_unaligned_be##type(*ptr);		\
> +	*ptr += sizeof(val);				\
> +	return val;					\
> +}
> +
> +GET_INC(16)
> +GET_INC(32)
> +
> +#endif
> -- 
> 2.12.3
> 

Some meta stuff:

* Add me to TO-field because I should probably review and eventually
  test these, right?
* CC to linux-security-module
* Why there is no RFC tag given that these are so quite large changes?
* Why in hell tpm2b.h?

/Jarkko