The image size is checked in efi_load_pe(). Avoid checking it twice.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

Currently if the bootefi command fails due to missing authentication, the
user gets no feedback.

Write a log message 'Image not authenticated' if LoadImage() fails due to
missing authentication.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

Use log_err() for error messages.
Replace debug() by EFI_PRINT().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

Bootxxxx variables are provided by the user and therefore cannot be
trusted. We have to validate them before usage.

A device path provided by a Bootxxxx variable must have an end node within
the indicated device path length.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

We need to check that device paths provided via UEFI variables are not
malformed.

Provide function efi_dp_check_length() to check if a device path has an
end node within a given number of bytes.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

If ResetSystem() is not implemented at runtime, it should return instead
of hanging in an endless loop. This allows the operating system to reset
the system by other means as Linux does. It also matches what EDK II
suggests in comments for functions ResetShutdown() and ResetWarm() in
OvmfPkg/Library/ResetSystemLib/ResetSystemLib.c.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

Under the current implementation, all the signatures, if any, in
a signed image must be verified before loading it.

Meanwhile, UEFI specification v2.8b section 32.5.3.3 says,
    Multiple signatures are allowed to exist in the binary’s certificate
    table (as per PE/COFF Section “Attribute Certificate Table”). Only
    one hash or signature is required to be present in db in order to pass
    validation, so long as neither the SHA-256 hash of the binary nor any
    present signature is reflected in dbx.

This patch makes the semantics of signature verification compliant with
the specification mentioned above.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

Under the new file-based variable implementation, the secure state
is always and falsely set to 0 (hence, the secure boot gets disabled)
after the reboot even if PK (and other signature database) has already
been enrolled in the previous boot.

This is because the secure state is set up *before* loading non-volatile
variables' values from saved data.

This patch fixes the order of variable initialization and secure state
initialization.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Fixes: 5f7dcf079de8 ("efi_loader: UEFI variable persistence")

In this commit, efi_signature_verify(with_sigdb) will be re-implemented
using pcks7_verify_one() in order to support certificates chain, where
the signer's certificate will be signed by an intermediate CA (certificate
authority) and the latter's certificate will also be signed by another CA
and so on.

What we need to do here is to search for certificates in a signature,
build up a chain of certificates and verify one by one. pkcs7_verify_one()
handles most of these steps except the last one.

pkcs7_verify_one() returns, if succeeded, the last certificate to verify,
which can be either a self-signed one or one that should be signed by one
of certificates in "db". Re-worked efi_signature_verify() will take care
of this step.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

This is a bug fix; Setting an authenticated variable may fail due to
a memory corruption in the authentication.

A temporary buffer will, if needed, be allocated to parse a variable's
authentication data, and some portion of buffer, specifically signer's
certificates, will be referenced by efi_signature_verify().

So the buffer should be kept valid until the authentication process
is finished.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>