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path: root/lib/efi_loader/efi_signature.c
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2020-08-14efi_loader: signature: correct a behavior against multiple signaturesAKASHI Takahiro
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>
2020-08-13efi_loader: signature: rework for intermediate certificates supportAKASHI Takahiro
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>
2020-07-11efi_loader: image_loader: add digest-based verification for signed imageAKASHI Takahiro
In case that a type of certificate in "db" or "dbx" is EFI_CERT_X509_SHA256_GUID, it is actually not a certificate which contains a public key for RSA decryption, but a digest of image to be loaded. If the value matches to a value calculated from a given binary image, it is granted for loading. With this patch, common digest check code, which used to be used for unsigned image verification, will be extracted from efi_signature_verify_with_sigdb() into efi_signature_lookup_digest(), and extra step for digest check will be added to efi_image_authenticate(). Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
2020-07-11efi_loader: image_loader: verification for all signatures should passAKASHI Takahiro
A signed image may have multiple signatures in - each WIN_CERTIFICATE in authenticode, and/or - each SignerInfo in pkcs7 SignedData (of WIN_CERTIFICATE) In the initial implementation of efi_image_authenticate(), the criteria of verification check for multiple signatures case is a bit ambiguous and it may cause inconsistent result. With this patch, we will make sure that verification check in efi_image_authenticate() should pass against all the signatures. The only exception would be - the case where a digest algorithm used in signature is not supported by U-Boot, or - the case where parsing some portion of authenticode has failed In those cases, we don't know how the signature be handled and should just ignore them. Please note that, due to this change, efi_signature_verify_with_sigdb()'s function prototype will be modified, taking "dbx" as well as "db" instead of outputing a "certificate." If "dbx" is null, the behavior would be the exact same as before. The function's name will be changed to efi_signature_verify() once current efi_signature_verify() has gone due to further improvement in intermediate certificates support. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
2020-07-11efi_loader: signature: make efi_hash_regions more genericAKASHI Takahiro
There are a couple of occurrences of hash calculations in which a new efi_hash_regions will be commonly used. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
2020-07-11efi_loader: signature: fix a size check against revocation listAKASHI Takahiro
Since the size check against an entry in efi_search_siglist() is incorrect, this function will never find out a to-be-matched certificate and its associated revocation time in the signature list. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
2020-07-03efi_loader: fix efi_image_region_add()Heinrich Schuchardt
Use start and end address consistently as half-open interval. Simplify the code. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-03efi_loader: signature: replace debug to EFI_PRINTAKASHI Takahiro
Just for style consistency, replace all the uses of debug to EFI_PRINT in efi_signature.c Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-06-03efi_loader: signature: move efi_guid_cert_type_pkcs7 to efi_signature.cAKASHI Takahiro
The global variable, efi_guid_cert_type_pkcs7, will also be used in efi_image_loader.c in a succeeding patch so as to correctly handle a signature type of authenticode in signed image. Meanwhile, it is currently defined in efi_variable.c. Once some secure storage solution for UEFI variables is introduced, efi_variable.c may not always be compiled in. So move the definition to efi_signature.c as a common place. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-05-04efi_loader: correct comments for efi_status_tHeinrich Schuchardt
EFI_STATUS is unsigned (UINTN). Hence it cannot be negative. Correct comments for 'Return:'. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-05-04efi_loader: fix unreachable statement in efi_sigstore_parse_siglistAKASHI Takahiro
"if (left < esl->signature_size)" is not reachable in a while loop. But it is still valuable in case that a given signature database is somehow corrupted. So fix the while loop condition. Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-05-04lib/crypto, efi_loader: move some headers to include/cryptoAKASHI Takahiro
Pkcs7_parse.h and x509_parser.h are used in UEFI subsystem, in particular, secure boot. So move them to include/crypto to avoid relative paths. Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Don't include include x509_parser.h twice. Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-04-16efi_loader: add signature database parserAKASHI Takahiro
efi_signature_parse_sigdb() is a helper function will be used to parse signature database variable and instantiate a signature store structure in later patches. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
2020-04-16efi_loader: add signature verification functionsAKASHI Takahiro
In this commit, implemented are a couple of helper functions which will be used to materialize variable authentication as well as image authentication in later patches. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>