hashes: Use Libgcrypt for hashing purposes

Switch the code of the Hashes class to use libgcrypt, which allows
us to use hardware-accelerated implementations of SHA1 and friends.

CMake/FindGcrypt.cmake

@@ -0,0 +1,25 @@
+# - Try to find GCRYPT
+# Once done, this will define
+#
+#  GCRYPT_FOUND - system has GCRYPT
+#  GCRYPT_INCLUDE_DIRS - the GCRYPT include directories
+#  GCRYPT_LIBRARIES - the GCRYPT library
+find_package(PkgConfig)
+
+pkg_check_modules(GCRYPT_PKGCONF libgcrypt)
+
+find_path(GCRYPT_INCLUDE_DIRS
+  NAMES gcrypt.h
+  PATHS ${GCRYPT_PKGCONF_INCLUDE_DIRS}
+)
+
+
+find_library(GCRYPT_LIBRARIES
+  NAMES gcrypt
+  PATHS ${GCRYPT_PKGCONF_LIBRARY_DIRS}
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(GCRYPT DEFAULT_MSG GCRYPT_INCLUDE_DIRS GCRYPT_LIBRARIES)
+
+mark_as_advanced(GCRYPT_INCLUDE_DIRS GCRYPT_LIBRARIES)

CMakeLists.txt

@@ -134,6 +134,8 @@ if (SECCOMP_FOUND)
   set(HAVE_SECCOMP 1)
 endif()
 
+find_package(Gcrypt REQUIRED)
+
 # Mount()ing and stat()ing and friends
 check_symbol_exists(statfs sys/vfs.h HAVE_VFS_H)
 check_include_files(sys/params.h HAVE_PARAMS_H)

apt-pkg/CMakeLists.txt

@@ -48,6 +48,7 @@ target_include_directories(apt-pkg
                                    $<$<BOOL:${UDEV_FOUND}>:${UDEV_INCLUDE_DIRS}>
                                    $<$<BOOL:${SYSTEMD_FOUND}>:${SYSTEMD_INCLUDE_DIRS}>
                                    ${ICONV_INCLUDE_DIRS}
+                                   $<$<BOOL:${GCRYPT_FOUND}>:${GCRYPT_INCLUDE_DIRS}>
 )
 
 target_link_libraries(apt-pkg
@@ -61,6 +62,7 @@ target_link_libraries(apt-pkg
                              $<$<BOOL:${UDEV_FOUND}>:${UDEV_LIBRARIES}>
                              $<$<BOOL:${SYSTEMD_FOUND}>:${SYSTEMD_LIBRARIES}>
                              ${ICONV_LIBRARIES}
+                             $<$<BOOL:${GCRYPT_FOUND}>:${GCRYPT_LIBRARIES}>
 )
 set_target_properties(apt-pkg PROPERTIES VERSION ${MAJOR}.${MINOR})
 set_target_properties(apt-pkg PROPERTIES SOVERSION ${MAJOR})

apt-pkg/contrib/hashes.cc

@@ -15,18 +15,30 @@
 #include <apt-pkg/configuration.h>
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/hashes.h>
-#include <apt-pkg/md5.h>
-#include <apt-pkg/sha1.h>
-#include <apt-pkg/sha2.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
@@ -286,39 +298,41 @@ bool HashStringList::operator!=(HashStringList const &other) const
 class PrivateHashes {
 public:
    unsigned long long FileSize;
-   unsigned int CalcHashes;
+   gcry_md_hd_t hd;
+
+   explicit PrivateHashes(unsigned int const CalcHashes) : FileSize(0)
+   {
+      gcry_md_open(&hd, 0, 0);
+      for (auto & Algo : Algorithms)
+      {
+	 if ((CalcHashes & Algo.ourAlgo) == Algo.ourAlgo)
+	    gcry_md_enable(hd, Algo.gcryAlgo);
+      }
+   }
 
-   explicit PrivateHashes(unsigned int const CalcHashes) : FileSize(0), CalcHashes(CalcHashes) {}
    explicit PrivateHashes(HashStringList const &Hashes) : FileSize(0) {
-      unsigned int calcHashes = Hashes.usable() ? 0 : ~0;
-      if (Hashes.find("MD5Sum") != NULL)
-	 calcHashes |= Hashes::MD5SUM;
-      if (Hashes.find("SHA1") != NULL)
-	 calcHashes |= Hashes::SHA1SUM;
-      if (Hashes.find("SHA256") != NULL)
-	 calcHashes |= Hashes::SHA256SUM;
-      if (Hashes.find("SHA512") != NULL)
-	 calcHashes |= Hashes::SHA512SUM;
-      CalcHashes = calcHashes;
+      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)
-      return true;
-   bool Res = true;
-   if ((d->CalcHashes & MD5SUM) == MD5SUM)
-      Res &= MD5.Add(Data, Size);
-   if ((d->CalcHashes & SHA1SUM) == SHA1SUM)
-      Res &= SHA1.Add(Data, Size);
-   if ((d->CalcHashes & SHA256SUM) == SHA256SUM)
-      Res &= SHA256.Add(Data, Size);
-   if ((d->CalcHashes & SHA512SUM) == SHA512SUM)
-      Res &= SHA512.Add(Data, Size);
-   d->FileSize += Size;
-   return Res;
+   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)
 {
@@ -364,18 +378,38 @@ bool Hashes::AddFD(FileFd &Fd,unsigned long long Size)
    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);
+   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;
-   if ((d->CalcHashes & MD5SUM) == MD5SUM)
-      hashes.push_back(HashString("MD5Sum", MD5.Result().Value()));
-   if ((d->CalcHashes & SHA1SUM) == SHA1SUM)
-      hashes.push_back(HashString("SHA1", SHA1.Result().Value()));
-   if ((d->CalcHashes & SHA256SUM) == SHA256SUM)
-      hashes.push_back(HashString("SHA256", SHA256.Result().Value()));
-   if ((d->CalcHashes & SHA512SUM) == SHA512SUM)
-      hashes.push_back(HashString("SHA512", SHA512.Result().Value()));
+   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;
 }
 Hashes::Hashes() : d(new PrivateHashes(~0)) { }

apt-pkg/contrib/hashes.h

@@ -173,10 +173,10 @@ class Hashes
    PrivateHashes * const d;
    /* TODO: those will disappear in the future as it is hard to add new ones this way.
     * Use Add* to build the results and get them via GetHashStringList() instead */
-   MD5Summation MD5;
-   SHA1Summation SHA1;
-   SHA256Summation SHA256;
-   SHA512Summation SHA512;
+   MD5Summation MD5 APT_PKG_590("Remove");
+   SHA1Summation SHA1 APT_PKG_590("Remove");
+   SHA256Summation SHA256 APT_PKG_590("Remove");
+   SHA512Summation SHA512 APT_PKG_590("Remove");
 
    public:
    static const int UntilEOF = 0;

debian/control

@@ -17,6 +17,7 @@ Build-Depends: cmake (>= 3.4),
                libbz2-dev,
                libdb-dev,
                libgnutls28-dev (>= 3.4.6),
+               libgcrypt20-dev,
                liblz4-dev (>= 0.0~r126),
                liblzma-dev,
                libseccomp-dev [amd64 arm64 armel armhf i386 mips mips64el mipsel ppc64el s390x hppa powerpc powerpcspe ppc64 x32],