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Diffstat (limited to 'lib/backupclient/BackupClientFileAttributes.cpp')
| -rwxr-xr-x | lib/backupclient/BackupClientFileAttributes.cpp | 773 |
1 files changed, 773 insertions, 0 deletions
diff --git a/lib/backupclient/BackupClientFileAttributes.cpp b/lib/backupclient/BackupClientFileAttributes.cpp new file mode 100755 index 00000000..4aa4edba --- /dev/null +++ b/lib/backupclient/BackupClientFileAttributes.cpp @@ -0,0 +1,773 @@ +// -------------------------------------------------------------------------- +// +// File +// Name: BackupClientFileAttributes.cpp +// Purpose: Storage of file attributes +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- + +#include "Box.h" + +#include <sys/types.h> +#include <sys/stat.h> +#include <string.h> +#include <unistd.h> +#include <limits.h> + +#include "BackupClientFileAttributes.h" +#include "CommonException.h" +#include "FileModificationTime.h" +#include "BoxTimeToUnix.h" +#include "BackupStoreException.h" +#include "CipherContext.h" +#include "CipherBlowfish.h" +#include "MD5Digest.h" + +#include "MemLeakFindOn.h" + +// set packing to one byte +#ifdef STRUCTURE_PATCKING_FOR_WIRE_USE_HEADERS +#include "BeginStructPackForWire.h" +#else +BEGIN_STRUCTURE_PACKING_FOR_WIRE +#endif + +#define ATTRIBUTETYPE_GENERIC_UNIX 1 + +#define ATTRIBUTE_ENCODING_BLOWFISH 2 + +typedef struct +{ + int32_t AttributeType; + u_int32_t UID; + u_int32_t GID; + u_int64_t ModificationTime; + u_int64_t AttrModificationTime; + u_int32_t UserDefinedFlags; + u_int32_t FileGenerationNumber; + u_int16_t Mode; + // Symbolic link filename may follow +} attr_StreamFormat; + +// This has wire packing so it's compatible across platforms +// Use wider than necessary sizes, just to be careful. +typedef struct +{ + int32_t uid, gid, mode; +} attributeHashData; + +// Use default packing +#ifdef STRUCTURE_PATCKING_FOR_WIRE_USE_HEADERS +#include "EndStructPackForWire.h" +#else +END_STRUCTURE_PACKING_FOR_WIRE +#endif + + +#define MAX_ATTRIBUTE_HASH_SECRET_LENGTH 256 + +// Hide private static variables from the rest of the world +// -- don't put them as static class variables to avoid openssl/evp.h being +// included all over the project. +namespace +{ + CipherContext sBlowfishEncrypt; + CipherContext sBlowfishDecrypt; + uint8_t sAttributeHashSecret[MAX_ATTRIBUTE_HASH_SECRET_LENGTH]; + int sAttributeHashSecretLength = 0; +} + + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::BackupClientFileAttributes() +// Purpose: Default constructor +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +BackupClientFileAttributes::BackupClientFileAttributes() + : mpClearAttributes(0) +{ + ASSERT(sizeof(u_int64_t) == sizeof(box_time_t)); +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::BackupClientFileAttributes(const BackupClientFileAttributes &) +// Purpose: Copy constructor +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +BackupClientFileAttributes::BackupClientFileAttributes(const BackupClientFileAttributes &rToCopy) + : StreamableMemBlock(rToCopy), // base class does the hard work + mpClearAttributes(0) +{ +} +BackupClientFileAttributes::BackupClientFileAttributes(const StreamableMemBlock &rToCopy) + : StreamableMemBlock(rToCopy), // base class does the hard work + mpClearAttributes(0) +{ +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::~BackupClientFileAttributes() +// Purpose: Destructor +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +BackupClientFileAttributes::~BackupClientFileAttributes() +{ + if(mpClearAttributes) + { + delete mpClearAttributes; + mpClearAttributes = 0; + } +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes &operator=(const BackupClientFileAttributes &) +// Purpose: Assignment operator +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +BackupClientFileAttributes &BackupClientFileAttributes::operator=(const BackupClientFileAttributes &rAttr) +{ + StreamableMemBlock::Set(rAttr); + RemoveClear(); // make sure no decrypted version held + return *this; +} +// Assume users play nice +BackupClientFileAttributes &BackupClientFileAttributes::operator=(const StreamableMemBlock &rAttr) +{ + StreamableMemBlock::Set(rAttr); + RemoveClear(); // make sure no decrypted version held + return *this; +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::operator==(const BackupClientFileAttributes &) +// Purpose: Comparison operator +// Created: 2003/10/09 +// +// -------------------------------------------------------------------------- +bool BackupClientFileAttributes::operator==(const BackupClientFileAttributes &rAttr) const +{ + EnsureClearAvailable(); + rAttr.EnsureClearAvailable(); + + return mpClearAttributes->operator==(*rAttr.mpClearAttributes); +} +// Too dangerous to allow -- put the two names the wrong way round, and it compares encrypted data. +/*bool BackupClientFileAttributes::operator==(const StreamableMemBlock &rAttr) const +{ + StreamableMemBlock *pDecoded = 0; + + try + { + EnsureClearAvailable(); + StreamableMemBlock *pDecoded = MakeClear(rAttr); + + // Compare using clear version + bool compared = mpClearAttributes->operator==(rAttr); + + // Delete temporary + delete pDecoded; + + return compared; + } + catch(...) + { + delete pDecoded; + throw; + } +}*/ + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::Compare(const BackupClientFileAttributes &, bool) +// Purpose: Compare, optionally ignoring the attribute modification time and/or modification time, and some data which is +// irrelevant in practise (eg file generation number) +// Created: 10/12/03 +// +// -------------------------------------------------------------------------- +bool BackupClientFileAttributes::Compare(const BackupClientFileAttributes &rAttr, bool IgnoreAttrModTime, bool IgnoreModTime) const +{ + EnsureClearAvailable(); + rAttr.EnsureClearAvailable(); + + // Check sizes are the same, as a first check + if(mpClearAttributes->GetSize() != rAttr.mpClearAttributes->GetSize()) + { + return false; + } + + // Then check the elements of the two things + // Bytes are checked in network order, but this doesn't matter as we're only checking for equality. + attr_StreamFormat *a1 = (attr_StreamFormat*)mpClearAttributes->GetBuffer(); + attr_StreamFormat *a2 = (attr_StreamFormat*)rAttr.mpClearAttributes->GetBuffer(); + + if(a1->AttributeType != a2->AttributeType + || a1->UID != a2->UID + || a1->GID != a2->GID + || a1->UserDefinedFlags != a2->UserDefinedFlags + || a1->Mode != a2->Mode) + { + return false; + } + + if(!IgnoreModTime) + { + if(a1->ModificationTime != a2->ModificationTime) + { + return false; + } + } + + if(!IgnoreAttrModTime) + { + if(a1->AttrModificationTime != a2->AttrModificationTime) + { + return false; + } + } + + // Check symlink string? + unsigned int size = mpClearAttributes->GetSize(); + if(size > sizeof(attr_StreamFormat)) + { + // Symlink strings don't match + if(::memcmp(a1 + 1, a2 + 1, size - sizeof(attr_StreamFormat)) != 0) + { + return false; + } + } + + // Passes all test, must be OK + return true; +} + + + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::ReadAttributes(const char *) +// Purpose: Read the attributes of the file, and store them ready for streaming. +// Optionally retrieve the modification time and attribute modification time. +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::ReadAttributes(const char *Filename, bool ZeroModificationTimes, box_time_t *pModTime, + box_time_t *pAttrModTime, int64_t *pFileSize, ino_t *pInodeNumber, bool *pHasMultipleLinks) +{ + StreamableMemBlock *pnewAttr = 0; + try + { + struct stat st; + if(::lstat(Filename, &st) != 0) + { + THROW_EXCEPTION(CommonException, OSFileError) + } + + // Modification times etc + if(pModTime) {*pModTime = FileModificationTime(st);} + if(pAttrModTime) {*pAttrModTime = FileAttrModificationTime(st);} + if(pFileSize) {*pFileSize = st.st_size;} + if(pInodeNumber) {*pInodeNumber = st.st_ino;} + if(pHasMultipleLinks) {*pHasMultipleLinks = (st.st_nlink > 1);} + + // Is it a link? + if((st.st_mode & S_IFMT) == S_IFLNK) + { + ReadAttributesLink(Filename, &st, ZeroModificationTimes); + return; + } + ASSERT((st.st_mode & S_IFMT) != S_IFLNK); + + // Now, can allocate the block + pnewAttr = new StreamableMemBlock(sizeof(attr_StreamFormat)); + + // Fill in the entries + attr_StreamFormat *pattr = (attr_StreamFormat*)pnewAttr->GetBuffer(); + +#define FILL_IN_ATTRIBUTES \ + ::memset(pattr, 0, sizeof(attr_StreamFormat)); \ + ASSERT(pattr != 0); \ + pattr->AttributeType = htonl(ATTRIBUTETYPE_GENERIC_UNIX); \ + pattr->UID = htonl(st.st_uid); \ + pattr->GID = htonl(st.st_gid); \ + if(ZeroModificationTimes) \ + { \ + pattr->ModificationTime = 0; \ + pattr->AttrModificationTime = 0; \ + } \ + else \ + { \ + pattr->ModificationTime = hton64(FileModificationTime(st)); \ + pattr->AttrModificationTime = hton64(FileAttrModificationTime(st)); \ + } \ + pattr->Mode = htons(st.st_mode); +#ifdef PLATFORM_stat_NO_st_flags + #define FILL_IN_ATTRIBUTES_2 \ + pattr->UserDefinedFlags = 0; \ + pattr->FileGenerationNumber = 0; +#else + #define FILL_IN_ATTRIBUTES_2 \ + pattr->UserDefinedFlags = htonl(st.st_flags); \ + pattr->FileGenerationNumber = htonl(st.st_gen); +#endif + + FILL_IN_ATTRIBUTES + FILL_IN_ATTRIBUTES_2 + + // Attributes ready. Encrypt into this block + EncryptAttr(*pnewAttr); + + // Store the new attributes + RemoveClear(); + mpClearAttributes = pnewAttr; + pnewAttr = 0; + } + catch(...) + { + // clean up + delete pnewAttr; + pnewAttr = 0; + throw; + } +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::ReadAttributesLink() +// Purpose: Private function, handles the case where a symbolic link is needed +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::ReadAttributesLink(const char *Filename, void *pst, bool ZeroModificationTimes) +{ + StreamableMemBlock *pnewAttr = 0; + try + { + // Avoid needing to have struct stat available when including header file + struct stat &st = *((struct stat *)pst); + // Make sure we're only called for symbolic links + ASSERT((st.st_mode & S_IFMT) == S_IFLNK); + + // Get the filename the link is linked to + char linkedTo[PATH_MAX+4]; + int linkedToSize = ::readlink(Filename, linkedTo, PATH_MAX); + if(linkedToSize == -1) + { + THROW_EXCEPTION(CommonException, OSFileError) + } + + // Now, can allocate the block + pnewAttr = new StreamableMemBlock(sizeof(attr_StreamFormat) + linkedToSize + 1); + + // Fill in the entries + attr_StreamFormat *pattr = (attr_StreamFormat*)pnewAttr->GetBuffer(); + + FILL_IN_ATTRIBUTES + FILL_IN_ATTRIBUTES_2 + + // Add the path name for the symbolic link + ::memcpy(pattr + 1, linkedTo, linkedToSize); + // Make sure it's neatly terminated + ((char*)(pattr + 1))[linkedToSize] = '\0'; + + // Attributes ready. Encrypt into this block + EncryptAttr(*pnewAttr); + + // Store the new attributes + RemoveClear(); + mpClearAttributes = pnewAttr; + pnewAttr = 0; + } + catch(...) + { + // clean up + delete pnewAttr; + pnewAttr = 0; + throw; + } +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::WriteAttributes(const char *) +// Purpose: Apply the stored attributes to the file +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::WriteAttributes(const char *Filename) const +{ + // Got something loaded + if(GetSize() <= 0) + { + THROW_EXCEPTION(BackupStoreException, AttributesNotLoaded); + } + + // Make sure there are clear attributes to use + EnsureClearAvailable(); + ASSERT(mpClearAttributes != 0); + + // Check if the decrypted attributes are small enough, and the type of attributes stored + if(mpClearAttributes->GetSize() < (int)sizeof(int32_t)) + { + THROW_EXCEPTION(BackupStoreException, AttributesNotUnderstood); + } + int32_t *type = (int32_t*)mpClearAttributes->GetBuffer(); + ASSERT(type != 0); + if(ntohl(*type) != ATTRIBUTETYPE_GENERIC_UNIX) + { + // Don't know what to do with these + THROW_EXCEPTION(BackupStoreException, AttributesNotUnderstood); + } + + // Check there is enough space for an attributes block + if(mpClearAttributes->GetSize() < (int)sizeof(attr_StreamFormat)) + { + // Too small + THROW_EXCEPTION(BackupStoreException, AttributesNotLoaded); + } + + // Get pointer to structure + attr_StreamFormat *pattr = (attr_StreamFormat*)mpClearAttributes->GetBuffer(); + + // is it a symlink? + int16_t mode = ntohs(pattr->Mode); + if((mode & S_IFMT) == S_IFLNK) + { + // Check things are sensible + if(mpClearAttributes->GetSize() < (int)sizeof(attr_StreamFormat) + 1) + { + // Too small + THROW_EXCEPTION(BackupStoreException, AttributesNotLoaded); + } + + // Make a symlink, first deleting anything in the way + ::unlink(Filename); + if(::symlink((char*)(pattr + 1), Filename) != 0) + { + THROW_EXCEPTION(CommonException, OSFileError) + } + } + + // If working as root, set user IDs + if(::geteuid() == 0) + { + #ifdef PLATFORM_LCHOWN_NOT_SUPPORTED + // only if not a link, can't set their owner on this platform + if((mode & S_IFMT) != S_IFLNK) + { + // Not a link, use normal chown + if(::chown(Filename, ntohl(pattr->UID), ntohl(pattr->GID)) != 0) + { + THROW_EXCEPTION(CommonException, OSFileError) + } + } + #else + if(::lchown(Filename, ntohl(pattr->UID), ntohl(pattr->GID)) != 0) // use the version which sets things on symlinks + { + THROW_EXCEPTION(CommonException, OSFileError) + } + #endif + } + + // Stop now if symlink, because otherwise it'll just be applied to the target + if((mode & S_IFMT) == S_IFLNK) + { + return; + } + + // Set modification time? + box_time_t modtime = ntoh64(pattr->ModificationTime); + if(modtime != 0) + { + // Work out times as timevals + struct timeval times[2]; + BoxTimeToTimeval(modtime, times[1]); + // Copy access time as well, why not, got to set it to something + times[0] = times[1]; + // Attr modification time will be changed anyway, nothing that can be done about it + + // Try to apply + if(::utimes(Filename, times) != 0) + { + THROW_EXCEPTION(CommonException, OSFileError) + } + } + + // Apply everything else... (allowable mode flags only) + if(::chmod(Filename, mode & (S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX)) != 0) // mode must be done last (think setuid) + { + THROW_EXCEPTION(CommonException, OSFileError) + } +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::IsSymLink() +// Purpose: Do these attributes represent a symbolic link? +// Created: 2003/10/07 +// +// -------------------------------------------------------------------------- +bool BackupClientFileAttributes::IsSymLink() const +{ + EnsureClearAvailable(); + + // Got the right kind of thing? + if(mpClearAttributes->GetSize() < (int)sizeof(int32_t)) + { + THROW_EXCEPTION(BackupStoreException, AttributesNotLoaded); + } + + // Get the type of attributes stored + int32_t *type = (int32_t*)mpClearAttributes->GetBuffer(); + ASSERT(type != 0); + if(ntohl(*type) == ATTRIBUTETYPE_GENERIC_UNIX && mpClearAttributes->GetSize() > (int)sizeof(attr_StreamFormat)) + { + // Check link + attr_StreamFormat *pattr = (attr_StreamFormat*)mpClearAttributes->GetBuffer(); + return ((ntohs(pattr->Mode)) & S_IFMT) == S_IFLNK; + } + + return false; +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::RemoveClear() +// Purpose: Private. Deletes any clear version of the attributes that may be held +// Created: 3/12/03 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::RemoveClear() const +{ + if(mpClearAttributes) + { + delete mpClearAttributes; + } + mpClearAttributes = 0; +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::EnsureClearAvailable() +// Purpose: Private. Makes sure the clear version is available +// Created: 3/12/03 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::EnsureClearAvailable() const +{ + if(mpClearAttributes == 0) + { + mpClearAttributes = MakeClear(*this); + } +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::MakeClear(const StreamableMemBlock &) +// Purpose: Static. Decrypts stored attributes. +// Created: 3/12/03 +// +// -------------------------------------------------------------------------- +StreamableMemBlock *BackupClientFileAttributes::MakeClear(const StreamableMemBlock &rEncrypted) +{ + // New block + StreamableMemBlock *pdecrypted = 0; + + try + { + // Check the block is big enough for IV and header + int ivSize = sBlowfishEncrypt.GetIVLength(); + if(rEncrypted.GetSize() <= (ivSize + 1)) + { + THROW_EXCEPTION(BackupStoreException, BadEncryptedAttributes); + } + + // How much space is needed for the output? + int maxDecryptedSize = sBlowfishDecrypt.MaxOutSizeForInBufferSize(rEncrypted.GetSize() - ivSize); + + // Allocate it + pdecrypted = new StreamableMemBlock(maxDecryptedSize); + + // ptr to block + uint8_t *encBlock = (uint8_t*)rEncrypted.GetBuffer(); + + // Check that the header has right type + if(encBlock[0] != ATTRIBUTE_ENCODING_BLOWFISH) + { + THROW_EXCEPTION(BackupStoreException, EncryptedAttributesHaveUnknownEncoding); + } + + // Set IV + sBlowfishDecrypt.SetIV(encBlock + 1); + + // Decrypt + int decryptedSize = sBlowfishDecrypt.TransformBlock(pdecrypted->GetBuffer(), maxDecryptedSize, encBlock + 1 + ivSize, rEncrypted.GetSize() - (ivSize + 1)); + + // Resize block to fit + pdecrypted->ResizeBlock(decryptedSize); + } + catch(...) + { + delete pdecrypted; + pdecrypted = 0; + } + + return pdecrypted; +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::SetBlowfishKey(const void *, int) +// Purpose: Static. Sets the key to use for encryption and decryption. +// Created: 3/12/03 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::SetBlowfishKey(const void *pKey, int KeyLength) +{ + // IVs set later + sBlowfishEncrypt.Reset(); + sBlowfishEncrypt.Init(CipherContext::Encrypt, CipherBlowfish(CipherDescription::Mode_CBC, pKey, KeyLength)); + sBlowfishDecrypt.Reset(); + sBlowfishDecrypt.Init(CipherContext::Decrypt, CipherBlowfish(CipherDescription::Mode_CBC, pKey, KeyLength)); +} + + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::EncryptAttr(const StreamableMemBlock &) +// Purpose: Private. Encrypt the given attributes into this block. +// Created: 3/12/03 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::EncryptAttr(const StreamableMemBlock &rToEncrypt) +{ + // Free any existing block + FreeBlock(); + + // Work out the maximum amount of space we need + int maxEncryptedSize = sBlowfishEncrypt.MaxOutSizeForInBufferSize(rToEncrypt.GetSize()); + // And the size of the IV + int ivSize = sBlowfishEncrypt.GetIVLength(); + + // Allocate this space + AllocateBlock(maxEncryptedSize + ivSize + 1); + + // Store the encoding byte + uint8_t *block = (uint8_t*)GetBuffer(); + block[0] = ATTRIBUTE_ENCODING_BLOWFISH; + + // Generate and store an IV for this attribute block + int ivSize2 = 0; + const void *iv = sBlowfishEncrypt.SetRandomIV(ivSize2); + ASSERT(ivSize == ivSize2); + + // Copy into the encrypted block + ::memcpy(block + 1, iv, ivSize); + + // Do the transform + int encrytedSize = sBlowfishEncrypt.TransformBlock(block + 1 + ivSize, maxEncryptedSize, rToEncrypt.GetBuffer(), rToEncrypt.GetSize()); + + // Resize this block + ResizeBlock(encrytedSize + ivSize + 1); +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::SetAttributeHashSecret(const void *, int) +// Purpose: Set the secret for the filename attribute hash +// Created: 25/4/04 +// +// -------------------------------------------------------------------------- +void BackupClientFileAttributes::SetAttributeHashSecret(const void *pSecret, int SecretLength) +{ + if(SecretLength > (int)sizeof(sAttributeHashSecret)) + { + SecretLength = sizeof(sAttributeHashSecret); + } + if(SecretLength < 0) + { + THROW_EXCEPTION(BackupStoreException, Internal) + } + + // Copy + ::memcpy(sAttributeHashSecret, pSecret, SecretLength); + sAttributeHashSecretLength = SecretLength; +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: BackupClientFileAttributes::GenerateAttributeHash(struct stat &, const std::string &) +// Purpose: Generate a 64 bit hash from the attributes, used to detect changes. +// Include filename in the hash, so that it changes from one file to another, +// so don't reveal identical attributes. +// Created: 25/4/04 +// +// -------------------------------------------------------------------------- +uint64_t BackupClientFileAttributes::GenerateAttributeHash(struct stat &st, const std::string &rFilename) +{ + if(sAttributeHashSecretLength == 0) + { + THROW_EXCEPTION(BackupStoreException, AttributeHashSecretNotSet) + } + + // Assemble stuff we're interested in + attributeHashData hashData; + memset(&hashData, 0, sizeof(hashData)); + // Use network byte order and large sizes to be cross platform + hashData.uid = htonl(st.st_uid); + hashData.gid = htonl(st.st_gid); + hashData.mode = htonl(st.st_mode); + + // Create a MD5 hash of the data, filename, and secret + MD5Digest digest; + digest.Add(&hashData, sizeof(hashData)); + digest.Add(rFilename.c_str(), rFilename.size()); + digest.Add(sAttributeHashSecret, sAttributeHashSecretLength); + digest.Finish(); + + // Return the first 64 bits of the hash + uint64_t result = *((uint64_t *)(digest.DigestAsData())); + return result; +} + + + |