Messages in this thread | | | From | "Peter Huewe" <> | Subject | Aw: [PATCH] tpm: introduce struct tpm_buf | Date | Tue, 2 Jun 2015 15:18:54 +0200 |
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Hi, > Betreff: [PATCH] tpm: introduce struct tpm_buf > This patch introduces struct tpm_buf that provides a string buffer for > constructing TPM commands. This allows to construct variable sized TPM > commands. This feature is needed for TPM 2.0 commands in order to allow > policy authentication and algorithmic agility. > > The commands in the tpm2-cmd.c have been updated to use struct tpm_buf. > Lots of awkward length calculations could be dropped because the buffer > knows its length. > > The code is is along the lines of the string buffer code in > security/trusted/trusted.h. >
> --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -382,6 +382,93 @@ struct tpm_cmd_t { > tpm_cmd_params params; > } __packed; > > +/* A string buffer type for constructing TPM commands. This is based on the > + * code in security/keys/trusted.h. > + */ > + > +#define TPM_BUF_SIZE 512 Where does 512 come from? What about longer commands? Isn't TPM_BUF_SIZE defined elsewhere as 4096? > > + > +struct tpm_buf { > + u8 data[TPM_BUF_SIZE]; > +}; > +
> +static inline void tpm_buf_append(struct tpm_buf *buf, > + const unsigned char *data, > + unsigned int len) > +{ > + struct tpm_input_header *head = (struct tpm_input_header *) buf->data; > + > + BUG_ON((len + tpm_buf_length(buf)) > TPM_BUF_SIZE); > + > + memcpy(&buf->data[tpm_buf_length(buf)], data, len); > + head->length = cpu_to_be32(tpm_buf_length(buf) + len); > +} > + > +static inline void tpm_buf_store(struct tpm_buf *buf, > + unsigned int pos, > + const unsigned char *data, > + unsigned int len) > +{ > + BUG_ON((pos + len) > TPM_BUF_SIZE); > + > + memcpy(&buf->data[pos], data, len); Isn't the updating of the length missing? > +}
Thanks, Peter
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