From: Gary R Hook Subject: Re: [Part2 PATCH v6.1 20/38] crypto: ccp: Implement SEV_PDH_CERT_EXPORT ioctl command Date: Tue, 24 Oct 2017 13:43:05 -0500 Message-ID: References: <20171020023413.122280-21-brijesh.singh@amd.com> <20171023221949.47898-1-brijesh.singh@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Borislav Petkov , Herbert Xu , Tom Lendacky , linux-crypto@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org To: Brijesh Singh , Borislav Petkov Return-path: In-Reply-To: <20171023221949.47898-1-brijesh.singh@amd.com> Content-Language: en-US Sender: kvm-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On 10/23/2017 05:19 PM, Brijesh Singh wrote: > The SEV_PDH_CERT_EXPORT command can be used to export the PDH and its > certificate chain. The command is defined in SEV spec section 5.10. > > Cc: Paolo Bonzini > Cc: "Radim Krčmář" > Cc: Borislav Petkov > Cc: Herbert Xu > Cc: Gary Hook > Cc: Tom Lendacky > Cc: linux-crypto@vger.kernel.org > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Brijesh Singh Acked-by: Gary R Hook > --- > > Changes since v6: > * when sev_do_cmd() and sev_platform_shutdown() fails then propogate > the error status code from sev_do_cmd() because it can give us > much better reason for the failure. > > drivers/crypto/ccp/psp-dev.c | 110 +++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 110 insertions(+) > > diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c > index 108fc06bcdb3..b9f594cb10c1 100644 > --- a/drivers/crypto/ccp/psp-dev.c > +++ b/drivers/crypto/ccp/psp-dev.c > @@ -390,6 +390,113 @@ static int sev_ioctl_do_pek_cert_import(struct sev_issue_cmd *argp) > return ret; > } > > +static int sev_ioctl_do_pdh_cert_export(struct sev_issue_cmd *argp) > +{ > + struct sev_user_data_pdh_cert_export input; > + void *pdh_blob = NULL, *cert_blob = NULL; > + struct sev_data_pdh_cert_export *data; > + int ret, err; > + > + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) > + return -EFAULT; > + > + data = kzalloc(sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + /* Userspace wants to query the certificate length */ > + if (!input.pdh_cert_address || !input.pdh_cert_len || > + !input.cert_chain_address || !input.cert_chain_address) > + goto cmd; > + > + /* allocate a physically contiguous buffer to store the PDH blob */ > + if (!access_ok(VERIFY_WRITE, input.pdh_cert_address, input.pdh_cert_len) || > + (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)) { > + ret = -EFAULT; > + goto e_free; > + } > + > + pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL); > + if (!pdh_blob) { > + ret = -ENOMEM; > + goto e_free; > + } > + > + data->pdh_cert_address = __psp_pa(pdh_blob); > + data->pdh_cert_len = input.pdh_cert_len; > + > + /* allocate a physically contiguous buffer to store the cert chain blob */ > + if (!access_ok(VERIFY_WRITE, input.cert_chain_address, input.cert_chain_len) || > + (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)) { > + ret = -EFAULT; > + goto e_free_pdh; > + } > + > + cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL); > + if (!cert_blob) { > + ret = -ENOMEM; > + goto e_free_pdh; > + } > + > + data->cert_chain_address = __psp_pa(cert_blob); > + data->cert_chain_len = input.cert_chain_len; > + > +cmd: > + ret = sev_platform_init(NULL, &argp->error); > + if (ret) > + goto e_free_cert; > + > + ret = sev_do_cmd(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error); > + > + /* > + * If we query the length, FW responded with expected data > + */ > + input.cert_chain_len = data->cert_chain_len; > + input.pdh_cert_len = data->pdh_cert_len; > + > + if (sev_platform_shutdown(&err)) { > + /* > + * If both sev_do_cmd() and sev_platform_shutdown() commands > + * failed then propogate the error code from the sev_do_cmd() > + * because it contains a useful status code for the command > + * failure. > + */ > + if (ret) > + goto e_free_cert; > + > + ret = -EIO; > + argp->error = err; > + goto e_free_cert; > + } > + > + if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) { > + ret = -EFAULT; > + goto e_free_cert; > + } > + > + if (pdh_blob) { > + if (copy_to_user((void __user *)input.pdh_cert_address, > + pdh_blob, input.pdh_cert_len)) { > + ret = -EFAULT; > + goto e_free_cert; > + } > + } > + > + if (cert_blob) { > + if (copy_to_user((void __user *)input.cert_chain_address, > + cert_blob, input.cert_chain_len)) > + ret = -EFAULT; > + } > + > +e_free_cert: > + kfree(cert_blob); > +e_free_pdh: > + kfree(pdh_blob); > +e_free: > + kfree(data); > + return ret; > +} > + > static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) > { > void __user *argp = (void __user *)arg; > @@ -425,6 +532,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) > case SEV_PEK_CERT_IMPORT: > ret = sev_ioctl_do_pek_cert_import(&input); > break; > + case SEV_PDH_CERT_EXPORT: > + ret = sev_ioctl_do_pdh_cert_export(&input); > + break; > default: > ret = -EINVAL; > goto out; >