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SecurityPkg/SecureBoot: Support RSA4096 and RSA3072
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REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3413

Cc: Jiewen Yao <[email protected]>
Cc: Jian J Wang <[email protected]>
Cc: Min Xu <[email protected]>
Cc: Zeyi Chen <[email protected]>
Cc: Fiona Wang <[email protected]>
Signed-off-by: Sheng Wei <[email protected]>
Reviewed-by: Jiewen Yao <[email protected]>
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@swei22 @mergify
swei22 authored and mergify[bot] committed Sep 7, 2023
1 parent 24da5c2 commit bbf1822
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Showing 8 changed files with 329 additions and 85 deletions.
225 changes: 191 additions & 34 deletions SecurityPkg/Library/AuthVariableLib/AuthService.c
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Original file line number Diff line number Diff line change
Expand Up @@ -29,12 +29,125 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
#include <Protocol/VariablePolicy.h>
#include <Library/VariablePolicyLib.h>

#define SHA_DIGEST_SIZE_MAX SHA512_DIGEST_SIZE

/**
Retrieves the size, in bytes, of the context buffer required for hash operations.
If this interface is not supported, then return zero.
@return The size, in bytes, of the context buffer required for hash operations.
@retval 0 This interface is not supported.
**/
typedef
UINTN
(EFIAPI *EFI_HASH_GET_CONTEXT_SIZE)(
VOID
);

/**
Initializes user-supplied memory pointed by Sha1Context as hash context for
subsequent use.
If HashContext is NULL, then return FALSE.
If this interface is not supported, then return FALSE.
@param[out] HashContext Pointer to Hashcontext being initialized.
@retval TRUE Hash context initialization succeeded.
@retval FALSE Hash context initialization failed.
@retval FALSE This interface is not supported.
**/
typedef
BOOLEAN
(EFIAPI *EFI_HASH_INIT)(
OUT VOID *HashContext
);

/**
Digests the input data and updates Hash context.
This function performs Hash digest on a data buffer of the specified size.
It can be called multiple times to compute the digest of long or discontinuous data streams.
Hash context should be already correctly initialized by HashInit(), and should not be finalized
by HashFinal(). Behavior with invalid context is undefined.
If HashContext is NULL, then return FALSE.
If this interface is not supported, then return FALSE.
@param[in, out] HashContext Pointer to the Hash context.
@param[in] Data Pointer to the buffer containing the data to be hashed.
@param[in] DataSize Size of Data buffer in bytes.
@retval TRUE SHA-1 data digest succeeded.
@retval FALSE SHA-1 data digest failed.
@retval FALSE This interface is not supported.
**/
typedef
BOOLEAN
(EFIAPI *EFI_HASH_UPDATE)(
IN OUT VOID *HashContext,
IN CONST VOID *Data,
IN UINTN DataSize
);

/**
Completes computation of the Hash digest value.
This function completes hash computation and retrieves the digest value into
the specified memory. After this function has been called, the Hash context cannot
be used again.
Hash context should be already correctly initialized by HashInit(), and should not be
finalized by HashFinal(). Behavior with invalid Hash context is undefined.
If HashContext is NULL, then return FALSE.
If HashValue is NULL, then return FALSE.
If this interface is not supported, then return FALSE.
@param[in, out] HashContext Pointer to the Hash context.
@param[out] HashValue Pointer to a buffer that receives the Hash digest
value.
@retval TRUE Hash digest computation succeeded.
@retval FALSE Hash digest computation failed.
@retval FALSE This interface is not supported.
**/
typedef
BOOLEAN
(EFIAPI *EFI_HASH_FINAL)(
IN OUT VOID *HashContext,
OUT UINT8 *HashValue
);

typedef struct {
UINT32 HashSize;
EFI_HASH_GET_CONTEXT_SIZE GetContextSize;
EFI_HASH_INIT Init;
EFI_HASH_UPDATE Update;
EFI_HASH_FINAL Final;
VOID **HashShaCtx;
UINT8 *OidValue;
UINTN OidLength;
} EFI_HASH_INFO;

//
// Public Exponent of RSA Key.
//
CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 };

CONST UINT8 mSha256OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01 };
UINT8 mSha256OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01 };
UINT8 mSha384OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02 };
UINT8 mSha512OidValue[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03 };

EFI_HASH_INFO mHashInfo[] = {
{ SHA256_DIGEST_SIZE, Sha256GetContextSize, Sha256Init, Sha256Update, Sha256Final, &mHashSha256Ctx, mSha256OidValue, 9 },
{ SHA384_DIGEST_SIZE, Sha384GetContextSize, Sha384Init, Sha384Update, Sha384Final, &mHashSha384Ctx, mSha384OidValue, 9 },
{ SHA512_DIGEST_SIZE, Sha512GetContextSize, Sha512Init, Sha512Update, Sha512Final, &mHashSha512Ctx, mSha512OidValue, 9 },
};

//
// Requirement for different signature type which have been defined in UEFI spec.
Expand Down Expand Up @@ -1090,26 +1203,28 @@ AuthServiceInternalCompareTimeStamp (
}

/**
Calculate SHA256 digest of SignerCert CommonName + ToplevelCert tbsCertificate
Calculate SHA digest of SignerCert CommonName + ToplevelCert tbsCertificate.
SignerCert and ToplevelCert are inside the signer certificate chain.
@param[in] HashAlgId Hash algorithm index.
@param[in] SignerCert A pointer to SignerCert data.
@param[in] SignerCertSize Length of SignerCert data.
@param[in] TopLevelCert A pointer to TopLevelCert data.
@param[in] TopLevelCertSize Length of TopLevelCert data.
@param[out] Sha256Digest Sha256 digest calculated.
@param[out] ShaDigest Sha digest calculated.
@return EFI_ABORTED Digest process failed.
@return EFI_SUCCESS SHA256 Digest is successfully calculated.
@return EFI_SUCCESS SHA Digest is successfully calculated.
**/
EFI_STATUS
CalculatePrivAuthVarSignChainSHA256Digest (
CalculatePrivAuthVarSignChainSHADigest (
IN UINT8 HashAlgId,
IN UINT8 *SignerCert,
IN UINTN SignerCertSize,
IN UINT8 *TopLevelCert,
IN UINTN TopLevelCertSize,
OUT UINT8 *Sha256Digest
OUT UINT8 *ShaDigest
)
{
UINT8 *TbsCert;
Expand All @@ -1119,6 +1234,11 @@ CalculatePrivAuthVarSignChainSHA256Digest (
BOOLEAN CryptoStatus;
EFI_STATUS Status;

if (HashAlgId >= (sizeof (mHashInfo) / sizeof (EFI_HASH_INFO))) {
DEBUG ((DEBUG_INFO, "%a Unsupported Hash Algorithm %d\n", __func__, HashAlgId));
return EFI_ABORTED;
}

CertCommonNameSize = sizeof (CertCommonName);

//
Expand All @@ -1141,30 +1261,30 @@ CalculatePrivAuthVarSignChainSHA256Digest (
//
// Digest SignerCert CN + TopLevelCert tbsCertificate
//
ZeroMem (Sha256Digest, SHA256_DIGEST_SIZE);
CryptoStatus = Sha256Init (mHashCtx);
ZeroMem (ShaDigest, mHashInfo[HashAlgId].HashSize);
CryptoStatus = mHashInfo[HashAlgId].Init (*(mHashInfo[HashAlgId].HashShaCtx));
if (!CryptoStatus) {
return EFI_ABORTED;
}

//
// '\0' is forced in CertCommonName. No overflow issue
//
CryptoStatus = Sha256Update (
mHashCtx,
CertCommonName,
AsciiStrLen (CertCommonName)
);
CryptoStatus = mHashInfo[HashAlgId].Update (
*(mHashInfo[HashAlgId].HashShaCtx),
CertCommonName,
AsciiStrLen (CertCommonName)
);
if (!CryptoStatus) {
return EFI_ABORTED;
}

CryptoStatus = Sha256Update (mHashCtx, TbsCert, TbsCertSize);
CryptoStatus = mHashInfo[HashAlgId].Update (*(mHashInfo[HashAlgId].HashShaCtx), TbsCert, TbsCertSize);
if (!CryptoStatus) {
return EFI_ABORTED;
}

CryptoStatus = Sha256Final (mHashCtx, Sha256Digest);
CryptoStatus = mHashInfo[HashAlgId].Final (*(mHashInfo[HashAlgId].HashShaCtx), ShaDigest);
if (!CryptoStatus) {
return EFI_ABORTED;
}
Expand Down Expand Up @@ -1516,9 +1636,10 @@ DeleteCertsFromDb (
/**
Insert signer's certificates for common authenticated variable with VariableName
and VendorGuid in AUTH_CERT_DB_DATA to "certdb" or "certdbv" according to
time based authenticated variable attributes. CertData is the SHA256 digest of
time based authenticated variable attributes. CertData is the SHA digest of
SignerCert CommonName + TopLevelCert tbsCertificate.
@param[in] HashAlgId Hash algorithm index.
@param[in] VariableName Name of authenticated Variable.
@param[in] VendorGuid Vendor GUID of authenticated Variable.
@param[in] Attributes Attributes of authenticated variable.
Expand All @@ -1536,6 +1657,7 @@ DeleteCertsFromDb (
**/
EFI_STATUS
InsertCertsToDb (
IN UINT8 HashAlgId,
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
IN UINT32 Attributes,
Expand All @@ -1556,12 +1678,16 @@ InsertCertsToDb (
UINT32 CertDataSize;
AUTH_CERT_DB_DATA *Ptr;
CHAR16 *DbName;
UINT8 Sha256Digest[SHA256_DIGEST_SIZE];
UINT8 ShaDigest[SHA_DIGEST_SIZE_MAX];

if ((VariableName == NULL) || (VendorGuid == NULL) || (SignerCert == NULL) || (TopLevelCert == NULL)) {
return EFI_INVALID_PARAMETER;
}

if (HashAlgId >= (sizeof (mHashInfo) / sizeof (EFI_HASH_INFO))) {
return EFI_INVALID_PARAMETER;
}

if ((Attributes & EFI_VARIABLE_NON_VOLATILE) != 0) {
//
// Get variable "certdb".
Expand Down Expand Up @@ -1618,20 +1744,22 @@ InsertCertsToDb (
// Construct new data content of variable "certdb" or "certdbv".
//
NameSize = (UINT32)StrLen (VariableName);
CertDataSize = sizeof (Sha256Digest);
CertDataSize = mHashInfo[HashAlgId].HashSize;
CertNodeSize = sizeof (AUTH_CERT_DB_DATA) + (UINT32)CertDataSize + NameSize * sizeof (CHAR16);
NewCertDbSize = (UINT32)DataSize + CertNodeSize;
if (NewCertDbSize > mMaxCertDbSize) {
return EFI_OUT_OF_RESOURCES;
}

Status = CalculatePrivAuthVarSignChainSHA256Digest (
Status = CalculatePrivAuthVarSignChainSHADigest (
HashAlgId,
SignerCert,
SignerCertSize,
TopLevelCert,
TopLevelCertSize,
Sha256Digest
ShaDigest
);

if (EFI_ERROR (Status)) {
return Status;
}
Expand Down Expand Up @@ -1663,7 +1791,7 @@ InsertCertsToDb (

CopyMem (
(UINT8 *)Ptr + sizeof (AUTH_CERT_DB_DATA) + NameSize * sizeof (CHAR16),
Sha256Digest,
ShaDigest,
CertDataSize
);

Expand Down Expand Up @@ -1790,6 +1918,37 @@ CleanCertsFromDb (
return Status;
}

/**
Find hash algorithm index.
@param[in] SigData Pointer to the PKCS#7 message.
@param[in] SigDataSize Length of the PKCS#7 message.
@retval UINT8 Hash Algorithm Index.
**/
UINT8
FindHashAlgorithmIndex (
IN UINT8 *SigData,
IN UINT32 SigDataSize
)
{
UINT8 i;

for (i = 0; i < (sizeof (mHashInfo) / sizeof (EFI_HASH_INFO)); i++) {
if ( ( (SigDataSize >= (13 + mHashInfo[i].OidLength))
&& ( ((*(SigData + 1) & TWO_BYTE_ENCODE) == TWO_BYTE_ENCODE)
&& (CompareMem (SigData + 13, mHashInfo[i].OidValue, mHashInfo[i].OidLength) == 0)))
|| ( ((SigDataSize >= (32 + mHashInfo[i].OidLength)))
&& ( ((*(SigData + 20) & TWO_BYTE_ENCODE) == TWO_BYTE_ENCODE)
&& (CompareMem (SigData + 32, mHashInfo[i].OidValue, mHashInfo[i].OidLength) == 0))))
{
break;
}
}

return i;
}

/**
Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
Expand Down Expand Up @@ -1857,8 +2016,9 @@ VerifyTimeBasedPayload (
UINTN CertStackSize;
UINT8 *CertsInCertDb;
UINT32 CertsSizeinDb;
UINT8 Sha256Digest[SHA256_DIGEST_SIZE];
UINT8 ShaDigest[SHA_DIGEST_SIZE_MAX];
EFI_CERT_DATA *CertDataPtr;
UINT8 HashAlgId;

//
// 1. TopLevelCert is the top-level issuer certificate in signature Signer Cert Chain
Expand Down Expand Up @@ -1928,7 +2088,7 @@ VerifyTimeBasedPayload (

//
// SignedData.digestAlgorithms shall contain the digest algorithm used when preparing the
// signature. Only a digest algorithm of SHA-256 is accepted.
// signature. Only a digest algorithm of SHA-256, SHA-384 or SHA-512 is accepted.
//
// According to PKCS#7 Definition (https://www.rfc-editor.org/rfc/rfc2315):
// SignedData ::= SEQUENCE {
Expand Down Expand Up @@ -1972,14 +2132,9 @@ VerifyTimeBasedPayload (
//
// Example generated with: https://wiki.archlinux.org/title/Unified_Extensible_Firmware_Interface/Secure_Boot#Manual_process
//
HashAlgId = FindHashAlgorithmIndex (SigData, SigDataSize);
if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
if ( ( (SigDataSize >= (13 + sizeof (mSha256OidValue)))
&& ( ((*(SigData + 1) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE)
|| (CompareMem (SigData + 13, &mSha256OidValue, sizeof (mSha256OidValue)) != 0)))
&& ( (SigDataSize >= (32 + sizeof (mSha256OidValue)))
&& ( ((*(SigData + 20) & TWO_BYTE_ENCODE) != TWO_BYTE_ENCODE)
|| (CompareMem (SigData + 32, &mSha256OidValue, sizeof (mSha256OidValue)) != 0))))
{
if (HashAlgId >= (sizeof (mHashInfo) / sizeof (EFI_HASH_INFO))) {
return EFI_SECURITY_VIOLATION;
}
}
Expand Down Expand Up @@ -2170,19 +2325,20 @@ VerifyTimeBasedPayload (
goto Exit;
}

if (CertsSizeinDb == SHA256_DIGEST_SIZE) {
if ((HashAlgId < (sizeof (mHashInfo) / sizeof (EFI_HASH_INFO))) && (CertsSizeinDb == mHashInfo[HashAlgId].HashSize)) {
//
// Check hash of signer cert CommonName + Top-level issuer tbsCertificate against data in CertDb
//
CertDataPtr = (EFI_CERT_DATA *)(SignerCerts + 1);
Status = CalculatePrivAuthVarSignChainSHA256Digest (
Status = CalculatePrivAuthVarSignChainSHADigest (
HashAlgId,
CertDataPtr->CertDataBuffer,
ReadUnaligned32 ((UINT32 *)&(CertDataPtr->CertDataLength)),
TopLevelCert,
TopLevelCertSize,
Sha256Digest
ShaDigest
);
if (EFI_ERROR (Status) || (CompareMem (Sha256Digest, CertsInCertDb, CertsSizeinDb) != 0)) {
if (EFI_ERROR (Status) || (CompareMem (ShaDigest, CertsInCertDb, CertsSizeinDb) != 0)) {
goto Exit;
}
} else {
Expand Down Expand Up @@ -2215,6 +2371,7 @@ VerifyTimeBasedPayload (
//
CertDataPtr = (EFI_CERT_DATA *)(SignerCerts + 1);
Status = InsertCertsToDb (
HashAlgId,
VariableName,
VendorGuid,
Attributes,
Expand Down
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