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-rw-r--r--apt-pkg/contrib/hashes.cc453
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diff --git a/apt-pkg/contrib/hashes.cc b/apt-pkg/contrib/hashes.cc
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+// -*- mode: cpp; mode: fold -*-
+// Description /*{{{*/
+/* ######################################################################
+
+ Hashes - Simple wrapper around the hash functions
+
+ This is just used to make building the methods simpler, this is the
+ only interface required..
+
+ ##################################################################### */
+ /*}}}*/
+// Include Files /*{{{*/
+#include <config.h>
+
+#include <apt-pkg/configuration.h>
+#include <apt-pkg/fileutl.h>
+#include <apt-pkg/hashes.h>
+#include <apt-pkg/macros.h>
+#include <apt-pkg/strutl.h>
+
+#include <algorithm>
+#include <iostream>
+#include <string>
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <gcrypt.h>
+ /*}}}*/
+
+static const constexpr struct HashAlgo
+{
+ const char *name;
+ int gcryAlgo;
+ Hashes::SupportedHashes ourAlgo;
+} Algorithms[] = {
+ {"MD5Sum", GCRY_MD_MD5, Hashes::MD5SUM},
+ {"SHA1", GCRY_MD_SHA1, Hashes::SHA1SUM},
+ {"SHA256", GCRY_MD_SHA256, Hashes::SHA256SUM},
+ {"SHA512", GCRY_MD_SHA512, Hashes::SHA512SUM},
+};
+
+const char * HashString::_SupportedHashes[] =
+{
+ "SHA512", "SHA256", "SHA1", "MD5Sum", "Checksum-FileSize", NULL
+};
+
+HashString::HashString()
+{
+}
+
+HashString::HashString(std::string Type, std::string Hash) : Type(Type), Hash(Hash)
+{
+}
+
+HashString::HashString(std::string StringedHash) /*{{{*/
+{
+ if (StringedHash.find(":") == std::string::npos)
+ {
+ // legacy: md5sum without "MD5Sum:" prefix
+ if (StringedHash.size() == 32)
+ {
+ Type = "MD5Sum";
+ Hash = StringedHash;
+ }
+ if(_config->FindB("Debug::Hashes",false) == true)
+ std::clog << "HashString(string): invalid StringedHash " << StringedHash << std::endl;
+ return;
+ }
+ std::string::size_type pos = StringedHash.find(":");
+ Type = StringedHash.substr(0,pos);
+ Hash = StringedHash.substr(pos+1, StringedHash.size() - pos);
+
+ if(_config->FindB("Debug::Hashes",false) == true)
+ std::clog << "HashString(string): " << Type << " : " << Hash << std::endl;
+}
+ /*}}}*/
+bool HashString::VerifyFile(std::string filename) const /*{{{*/
+{
+ std::string fileHash = GetHashForFile(filename);
+
+ if(_config->FindB("Debug::Hashes",false) == true)
+ std::clog << "HashString::VerifyFile: got: " << fileHash << " expected: " << toStr() << std::endl;
+
+ return (fileHash == Hash);
+}
+ /*}}}*/
+bool HashString::FromFile(std::string filename) /*{{{*/
+{
+ // pick the strongest hash
+ if (Type == "")
+ Type = _SupportedHashes[0];
+
+ Hash = GetHashForFile(filename);
+ return true;
+}
+ /*}}}*/
+std::string HashString::GetHashForFile(std::string filename) const /*{{{*/
+{
+ std::string fileHash;
+
+ FileFd Fd(filename, FileFd::ReadOnly);
+ if(strcasecmp(Type.c_str(), "MD5Sum") == 0)
+ {
+ Hashes MD5(Hashes::MD5SUM);
+ MD5.AddFD(Fd);
+ fileHash = MD5.GetHashString(Hashes::MD5SUM).Hash;
+ }
+ else if (strcasecmp(Type.c_str(), "SHA1") == 0)
+ {
+ Hashes SHA1(Hashes::SHA1SUM);
+ SHA1.AddFD(Fd);
+ fileHash = SHA1.GetHashString(Hashes::SHA1SUM).Hash;
+ }
+ else if (strcasecmp(Type.c_str(), "SHA256") == 0)
+ {
+ Hashes SHA256(Hashes::SHA256SUM);
+ SHA256.AddFD(Fd);
+ fileHash = SHA256.GetHashString(Hashes::SHA256SUM).Hash;
+ }
+ else if (strcasecmp(Type.c_str(), "SHA512") == 0)
+ {
+ Hashes SHA512(Hashes::SHA512SUM);
+ SHA512.AddFD(Fd);
+ fileHash = SHA512.GetHashString(Hashes::SHA512SUM).Hash;
+ }
+ else if (strcasecmp(Type.c_str(), "Checksum-FileSize") == 0)
+ strprintf(fileHash, "%llu", Fd.FileSize());
+ Fd.Close();
+
+ return fileHash;
+}
+ /*}}}*/
+const char** HashString::SupportedHashes() /*{{{*/
+{
+ return _SupportedHashes;
+}
+ /*}}}*/
+APT_PURE bool HashString::empty() const /*{{{*/
+{
+ return (Type.empty() || Hash.empty());
+}
+ /*}}}*/
+
+APT_PURE static bool IsConfigured(const char *name, const char *what)
+{
+ std::string option;
+ strprintf(option, "APT::Hashes::%s::%s", name, what);
+ return _config->FindB(option, false);
+}
+
+APT_PURE bool HashString::usable() const /*{{{*/
+{
+ return (
+ (Type != "Checksum-FileSize") &&
+ (Type != "MD5Sum") &&
+ (Type != "SHA1") &&
+ !IsConfigured(Type.c_str(), "Untrusted")
+ );
+}
+ /*}}}*/
+std::string HashString::toStr() const /*{{{*/
+{
+ return Type + ":" + Hash;
+}
+ /*}}}*/
+APT_PURE bool HashString::operator==(HashString const &other) const /*{{{*/
+{
+ return (strcasecmp(Type.c_str(), other.Type.c_str()) == 0 && Hash == other.Hash);
+}
+APT_PURE bool HashString::operator!=(HashString const &other) const
+{
+ return !(*this == other);
+}
+ /*}}}*/
+
+bool HashStringList::usable() const /*{{{*/
+{
+ if (empty() == true)
+ return false;
+ std::string const forcedType = _config->Find("Acquire::ForceHash", "");
+ if (forcedType.empty() == true)
+ {
+ // See if there is at least one usable hash
+ return std::any_of(list.begin(), list.end(), [](auto const &hs) { return hs.usable(); });
+ }
+ return find(forcedType) != NULL;
+}
+ /*}}}*/
+HashString const * HashStringList::find(char const * const type) const /*{{{*/
+{
+ if (type == NULL || type[0] == '\0')
+ {
+ std::string const forcedType = _config->Find("Acquire::ForceHash", "");
+ if (forcedType.empty() == false)
+ return find(forcedType.c_str());
+ for (char const * const * t = HashString::SupportedHashes(); *t != NULL; ++t)
+ for (std::vector<HashString>::const_iterator hs = list.begin(); hs != list.end(); ++hs)
+ if (strcasecmp(hs->HashType().c_str(), *t) == 0)
+ return &*hs;
+ return NULL;
+ }
+ for (std::vector<HashString>::const_iterator hs = list.begin(); hs != list.end(); ++hs)
+ if (strcasecmp(hs->HashType().c_str(), type) == 0)
+ return &*hs;
+ return NULL;
+}
+ /*}}}*/
+unsigned long long HashStringList::FileSize() const /*{{{*/
+{
+ HashString const * const hsf = find("Checksum-FileSize");
+ if (hsf == NULL)
+ return 0;
+ std::string const hv = hsf->HashValue();
+ return strtoull(hv.c_str(), NULL, 10);
+}
+ /*}}}*/
+bool HashStringList::FileSize(unsigned long long const Size) /*{{{*/
+{
+ return push_back(HashString("Checksum-FileSize", std::to_string(Size)));
+}
+ /*}}}*/
+bool HashStringList::supported(char const * const type) /*{{{*/
+{
+ for (char const * const * t = HashString::SupportedHashes(); *t != NULL; ++t)
+ if (strcasecmp(*t, type) == 0)
+ return true;
+ return false;
+}
+ /*}}}*/
+bool HashStringList::push_back(const HashString &hashString) /*{{{*/
+{
+ if (hashString.HashType().empty() == true ||
+ hashString.HashValue().empty() == true ||
+ supported(hashString.HashType().c_str()) == false)
+ return false;
+
+ // ensure that each type is added only once
+ HashString const * const hs = find(hashString.HashType().c_str());
+ if (hs != NULL)
+ return *hs == hashString;
+
+ list.push_back(hashString);
+ return true;
+}
+ /*}}}*/
+bool HashStringList::VerifyFile(std::string filename) const /*{{{*/
+{
+ if (usable() == false)
+ return false;
+
+ Hashes hashes(*this);
+ FileFd file(filename, FileFd::ReadOnly);
+ HashString const * const hsf = find("Checksum-FileSize");
+ if (hsf != NULL)
+ {
+ std::string fileSize;
+ strprintf(fileSize, "%llu", file.FileSize());
+ if (hsf->HashValue() != fileSize)
+ return false;
+ }
+ hashes.AddFD(file);
+ HashStringList const hsl = hashes.GetHashStringList();
+ return hsl == *this;
+}
+ /*}}}*/
+bool HashStringList::operator==(HashStringList const &other) const /*{{{*/
+{
+ std::string const forcedType = _config->Find("Acquire::ForceHash", "");
+ if (forcedType.empty() == false)
+ {
+ HashString const * const hs = find(forcedType);
+ HashString const * const ohs = other.find(forcedType);
+ if (hs == NULL || ohs == NULL)
+ return false;
+ return *hs == *ohs;
+ }
+ short matches = 0;
+ for (const_iterator hs = begin(); hs != end(); ++hs)
+ {
+ HashString const * const ohs = other.find(hs->HashType());
+ if (ohs == NULL)
+ continue;
+ if (*hs != *ohs)
+ return false;
+ ++matches;
+ }
+ if (matches == 0)
+ return false;
+ return true;
+}
+bool HashStringList::operator!=(HashStringList const &other) const
+{
+ return !(*this == other);
+}
+ /*}}}*/
+
+// PrivateHashes /*{{{*/
+class PrivateHashes {
+public:
+ unsigned long long FileSize;
+ gcry_md_hd_t hd;
+
+ void maybeInit()
+ {
+
+ // Yikes, we got to initialize libgcrypt, or we get warnings. But we
+ // abstract away libgcrypt in Hashes from our users - they are not
+ // supposed to know what the hashing backend is, so we can't force
+ // them to init themselves as libgcrypt folks want us to. So this
+ // only leaves us with this option...
+ if (!gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P))
+ {
+ if (!gcry_check_version(nullptr))
+ {
+ fprintf(stderr, "libgcrypt is too old (need %s, have %s)\n",
+ "nullptr", gcry_check_version(NULL));
+ exit(2);
+ }
+
+ gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
+ }
+ }
+
+ explicit PrivateHashes(unsigned int const CalcHashes) : FileSize(0)
+ {
+ maybeInit();
+ gcry_md_open(&hd, 0, 0);
+ for (auto & Algo : Algorithms)
+ {
+ if ((CalcHashes & Algo.ourAlgo) == Algo.ourAlgo)
+ gcry_md_enable(hd, Algo.gcryAlgo);
+ }
+ }
+
+ explicit PrivateHashes(HashStringList const &Hashes) : FileSize(0) {
+ maybeInit();
+ gcry_md_open(&hd, 0, 0);
+ for (auto & Algo : Algorithms)
+ {
+ if (not Hashes.usable() || Hashes.find(Algo.name) != NULL)
+ gcry_md_enable(hd, Algo.gcryAlgo);
+ }
+ }
+ ~PrivateHashes()
+ {
+ gcry_md_close(hd);
+ }
+};
+ /*}}}*/
+// Hashes::Add* - Add the contents of data or FD /*{{{*/
+bool Hashes::Add(const unsigned char * const Data, unsigned long long const Size)
+{
+ if (Size != 0)
+ {
+ gcry_md_write(d->hd, Data, Size);
+ d->FileSize += Size;
+ }
+ return true;
+}
+bool Hashes::AddFD(int const Fd,unsigned long long Size)
+{
+ unsigned char Buf[APT_BUFFER_SIZE];
+ bool const ToEOF = (Size == UntilEOF);
+ while (Size != 0 || ToEOF)
+ {
+ decltype(Size) n = sizeof(Buf);
+ if (!ToEOF) n = std::min(Size, n);
+ ssize_t const Res = read(Fd,Buf,n);
+ if (Res < 0 || (!ToEOF && Res != (ssize_t) n)) // error, or short read
+ return false;
+ if (ToEOF && Res == 0) // EOF
+ break;
+ Size -= Res;
+ if (Add(Buf, Res) == false)
+ return false;
+ }
+ return true;
+}
+bool Hashes::AddFD(FileFd &Fd,unsigned long long Size)
+{
+ unsigned char Buf[APT_BUFFER_SIZE];
+ bool const ToEOF = (Size == 0);
+ while (Size != 0 || ToEOF)
+ {
+ decltype(Size) n = sizeof(Buf);
+ if (!ToEOF) n = std::min(Size, n);
+ decltype(Size) a = 0;
+ if (Fd.Read(Buf, n, &a) == false) // error
+ return false;
+ if (ToEOF == false)
+ {
+ if (a != n) // short read
+ return false;
+ }
+ else if (a == 0) // EOF
+ break;
+ Size -= a;
+ if (Add(Buf, a) == false)
+ return false;
+ }
+ return true;
+}
+ /*}}}*/
+
+static APT_PURE std::string HexDigest(gcry_md_hd_t hd, int algo)
+{
+ char Conv[16] =
+ {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b',
+ 'c', 'd', 'e', 'f'};
+
+ auto Size = gcry_md_get_algo_dlen(algo);
+ assert(Size <= 512/8);
+ char Result[((Size)*2) + 1];
+ Result[(Size)*2] = 0;
+
+ auto Sum = gcry_md_read(hd, algo);
+
+ // Convert each char into two letters
+ size_t J = 0;
+ size_t I = 0;
+ for (; I != (Size)*2; J++, I += 2)
+ {
+ Result[I] = Conv[Sum[J] >> 4];
+ Result[I + 1] = Conv[Sum[J] & 0xF];
+ }
+ return std::string(Result);
+};
+
+HashStringList Hashes::GetHashStringList()
+{
+ HashStringList hashes;
+ for (auto & Algo : Algorithms)
+ if (gcry_md_is_enabled(d->hd, Algo.gcryAlgo))
+ hashes.push_back(HashString(Algo.name, HexDigest(d->hd, Algo.gcryAlgo)));
+ hashes.FileSize(d->FileSize);
+
+ return hashes;
+}
+
+HashString Hashes::GetHashString(SupportedHashes hash)
+{
+ for (auto & Algo : Algorithms)
+ if (hash == Algo.ourAlgo)
+ return HashString(Algo.name, HexDigest(d->hd, Algo.gcryAlgo));
+
+ abort();
+}
+Hashes::Hashes() : d(new PrivateHashes(~0)) { }
+Hashes::Hashes(unsigned int const Hashes) : d(new PrivateHashes(Hashes)) {}
+Hashes::Hashes(HashStringList const &Hashes) : d(new PrivateHashes(Hashes)) {}
+Hashes::~Hashes() { delete d; }