Merge branch 'master' of https://github.com/calamares/calamares into development

src/libcalamares/CMakeLists.txt

@@ -39,7 +39,7 @@ set( libSources
 
     # Modules
     modulesystem/InstanceKey.cpp
-    
+
     # Network service
     network/Manager.cpp
 
@@ -50,6 +50,7 @@ set( libSources
     utils/CalamaresUtilsSystem.cpp
     utils/CommandList.cpp
     utils/Dirs.cpp
+    utils/Entropy.cpp
     utils/Logger.cpp
     utils/PluginFactory.cpp
     utils/Retranslator.cpp

src/libcalamares/utils/Entropy.cpp

@@ -0,0 +1,124 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019-2020, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Entropy.h"
+
+#include <QFile>
+
+#include <random>
+
+CalamaresUtils::EntropySource
+CalamaresUtils::getEntropy( int size, QByteArray& b )
+{
+    b.clear();
+    if ( size < 1 )
+    {
+        return EntropySource::None;
+    }
+
+    b.resize( size );
+    char* buffer = b.data();
+    std::fill( buffer, buffer + size, 0xcb );
+
+    int readSize = 0;
+    QFile urandom( "/dev/urandom" );
+    if ( urandom.exists() && urandom.open( QIODevice::ReadOnly ) )
+    {
+        readSize = urandom.read( buffer, size );
+        urandom.close();
+    }
+
+    if ( readSize >= size )
+    {
+        return EntropySource::URandom;
+    }
+
+    // If it wasn't available, or did not return enough bytes,
+    // complete it with twister (and tell the client).
+    std::random_device r;
+    std::seed_seq seed { r(), r(), r(), r(), r(), r(), r(), r() };
+    std::mt19937_64 twister( seed );
+
+    std::uint64_t next = 0;
+    do
+    {
+        next = twister();
+        // Eight times, for a 64-bit next
+#define GET_ONE_BYTE \
+    if ( readSize < size ) \
+    { \
+        buffer[ readSize++ ] = next & 0xff; \
+        next = next >> 8; \
+    }
+        GET_ONE_BYTE
+        GET_ONE_BYTE
+        GET_ONE_BYTE
+        GET_ONE_BYTE
+        GET_ONE_BYTE
+        GET_ONE_BYTE
+        GET_ONE_BYTE
+        GET_ONE_BYTE
+    } while ( readSize < size );
+
+    return EntropySource::Twister;
+}
+
+CalamaresUtils::EntropySource
+CalamaresUtils::getPrintableEntropy( int size, QString& s )
+{
+    s.clear();
+    if ( size < 1 )
+    {
+        return EntropySource::None;
+    }
+
+    static const char salt_chars[] = { '.', '/', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
+                                       'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
+                                       'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
+                                       'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' };
+    static_assert( sizeof( salt_chars ) == 64, "Missing salt_chars" );
+
+    // Number of bytes we're going to need
+    int byteSize = ( ( size * 6 ) / 8 ) + 1;
+    QByteArray b;
+    EntropySource r = getEntropy( byteSize, b );
+
+    int bitsLeft = 0;
+    int byteOffset = 0;
+    qint64 next = 0;
+    do
+    {
+        if ( bitsLeft < 6 )
+        {
+            next = ( next << 8 ) | b.at( byteOffset++ );
+            bitsLeft += 8;
+        }
+        char c = salt_chars[ next & 0b0111111 ];
+        next >>= 6;
+        bitsLeft -= 6;
+        s.append( c );
+    } while ( ( s.length() < size ) && ( byteOffset < b.size() ) );
+
+    if ( s.length() < size )
+    {
+        // It's incomplete, not really no-entropy
+        return EntropySource::None;
+    }
+
+    return r;
+}

src/libcalamares/utils/Entropy.h

@@ -0,0 +1,53 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019-2020, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef UTILS_ENTROPY_H
+#define UTILS_ENTROPY_H
+
+#include "DllMacro.h"
+
+#include <QByteArray>
+
+namespace CalamaresUtils
+{
+/// @brief Which entropy source was actually used for the entropy.
+enum class EntropySource
+{
+    None,  ///< Buffer is empty, no random data
+    URandom,  ///< Read from /dev/urandom
+    Twister  ///< Generated by pseudo-random
+};
+
+/** @brief Fill buffer @p b with exactly @p size random bytes
+ *
+ * The array is cleared and resized, then filled with 0xcb
+ * "just in case", after which it is filled with random
+ * bytes from a suitable source. Returns which source was used.
+ */
+DLLEXPORT EntropySource getEntropy( int size, QByteArray& b );
+
+/** @brief Fill string @p s with exactly @p size random printable ASCII characters
+ *
+ * The characters are picked from a set of 64 (2^6). The string
+ * contains 6 * size bits of entropy. * Returns which source was used.
+ * @see getEntropy
+ */
+DLLEXPORT EntropySource getPrintableEntropy( int size, QString& s );
+}  // namespace CalamaresUtils
+
+#endif

src/libcalamares/utils/Tests.cpp

@@ -19,6 +19,7 @@
 #include "Tests.h"
 
 #include "CalamaresUtilsSystem.h"
+#include "Entropy.h"
 #include "Logger.h"
 #include "UMask.h"
 #include "Yaml.h"
@@ -176,3 +177,47 @@ LibCalamaresTests::testUmask()
     QCOMPARE( CalamaresUtils::setUMask( 022 ), m );
     QCOMPARE( CalamaresUtils::setUMask( m ), 022 );
 }
+
+void
+LibCalamaresTests::testEntropy()
+{
+    QByteArray data;
+
+    auto r0 = CalamaresUtils::getEntropy( 0, data );
+    QCOMPARE( CalamaresUtils::EntropySource::None, r0 );
+    QCOMPARE( data.size(), 0 );
+
+    auto r1 = CalamaresUtils::getEntropy( 16, data );
+    QVERIFY( r1 != CalamaresUtils::EntropySource::None );
+    QCOMPARE( data.size(), 16 );
+    // This can randomly fail (but not often)
+    QVERIFY( data.at( data.size() - 1 ) != char( 0xcb ) );
+
+    auto r2 = CalamaresUtils::getEntropy( 8, data );
+    QVERIFY( r2 != CalamaresUtils::EntropySource::None );
+    QCOMPARE( data.size(), 8 );
+    QCOMPARE( r1, r2 );
+    // This can randomly fail (but not often)
+    QVERIFY( data.at( data.size() - 1 ) != char( 0xcb ) );
+}
+
+void
+LibCalamaresTests::testPrintableEntropy()
+{
+    QString s;
+
+    auto r0 = CalamaresUtils::getPrintableEntropy( 0, s );
+    QCOMPARE( CalamaresUtils::EntropySource::None, r0 );
+    QCOMPARE( s.length(), 0 );
+
+    auto r1 = CalamaresUtils::getPrintableEntropy( 16, s );
+    QVERIFY( r1 != CalamaresUtils::EntropySource::None );
+    QCOMPARE( s.length(), 16 );
+    for ( QChar c : s )
+    {
+        QVERIFY( c.isPrint() );
+        QCOMPARE( c.row(), 0 );
+        QVERIFY( c.cell() > 32 );  // ASCII SPACE
+        QVERIFY( c.cell() < 127 );
+    }
+}

src/libcalamares/utils/Tests.h

@@ -39,6 +39,10 @@ private Q_SLOTS:
 
     /** @brief Test that all the UMask objects work correctly. */
     void testUmask();
+
+    /** @brief Tests the entropy functions. */
+    void testEntropy();
+    void testPrintableEntropy();
 };
 
 #endif

src/modules/machineid/Workers.cpp

@@ -3,7 +3,7 @@
  *   Copyright 2014, Kevin Kofler <kevin.kofler@chello.at>
  *   Copyright 2016, Philip Müller <philm@manjaro.org>
  *   Copyright 2017, Alf Gaida <agaida@siduction.org>
- *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *   Copyright 2019-2020, Adriaan de Groot <groot@kde.org>
  *
  *   Calamares is free software: you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -22,6 +22,7 @@
 #include "Workers.h"
 
 #include "utils/CalamaresUtilsSystem.h"
+#include "utils/Entropy.h"
 #include "utils/Logger.h"
 
 #include <QFile>
@@ -83,7 +84,7 @@ getUrandomPoolSize()
         {
             if ( v.endsWith( '\n' ) )
             {
-                v.chop(1);
+                v.chop( 1 );
             }
             bool ok = false;
             poolSize = v.toInt( &ok );
@@ -93,44 +94,42 @@ getUrandomPoolSize()
             }
         }
     }
-    return (poolSize >= minimumPoolSize) ? poolSize : minimumPoolSize;
+    return ( poolSize >= minimumPoolSize ) ? poolSize : minimumPoolSize;
 }
 
 Calamares::JobResult
 createNewEntropy( int poolSize, const QString& rootMountPoint, const QString& fileName )
 {
-    QFile urandom( "/dev/urandom" );
-    if ( urandom.exists() && urandom.open( QIODevice::ReadOnly ) )
+    QFile entropyFile( rootMountPoint + fileName );
+    if ( entropyFile.exists() )
     {
-        QByteArray data = urandom.read( poolSize );
-        urandom.close();
-
-        QFile entropyFile( rootMountPoint + fileName );
-        if ( entropyFile.exists() )
-        {
-            cWarning() << "Entropy file" << ( rootMountPoint + fileName ) << "already exists.";
-            return Calamares::JobResult::ok();  // .. anyway
-        }
-        if ( !entropyFile.open( QIODevice::WriteOnly ) )
-        {
-            return Calamares::JobResult::error(
-                QObject::tr( "File not found" ),
-                QObject::tr( "Could not create new random file <pre>%1</pre>." ).arg( fileName ) );
-        }
-        entropyFile.write( data );
-        entropyFile.close();
-        if ( entropyFile.size() < data.length() )
-        {
-            cWarning() << "Entropy file is" << entropyFile.size() << "bytes, random data was" << data.length();
-        }
-        if ( data.length() < poolSize )
-        {
-            cWarning() << "Entropy data is" << data.length() << "bytes, rather than poolSize" << poolSize;
-        }
+        cWarning() << "Entropy file" << ( rootMountPoint + fileName ) << "already exists.";
+        return Calamares::JobResult::ok();  // .. anyway
     }
-    return Calamares::JobResult::error(
-        QObject::tr( "File not found" ),
-        QObject::tr( "Could not read random file <pre>%1</pre>." ).arg( QStringLiteral( "/dev/urandom" ) ) );
+    if ( !entropyFile.open( QIODevice::WriteOnly ) )
+    {
+        return Calamares::JobResult::error(
+            QObject::tr( "File not found" ),
+            QObject::tr( "Could not create new random file <pre>%1</pre>." ).arg( fileName ) );
+    }
+
+    QByteArray data;
+    CalamaresUtils::EntropySource source = CalamaresUtils::getEntropy( poolSize, data );
+    entropyFile.write( data );
+    entropyFile.close();
+    if ( entropyFile.size() < data.length() )
+    {
+        cWarning() << "Entropy file is" << entropyFile.size() << "bytes, random data was" << data.length();
+    }
+    if ( data.length() < poolSize )
+    {
+        cWarning() << "Entropy data is" << data.length() << "bytes, rather than poolSize" << poolSize;
+    }
+    if ( source != CalamaresUtils::EntropySource::URandom )
+    {
+        cWarning() << "Entropy data for pool is low-quality.";
+    }
+    return Calamares::JobResult::ok();
 }
 
 

src/modules/users/SetPasswordJob.cpp

@@ -22,6 +22,7 @@
 #include "GlobalStorage.h"
 #include "JobQueue.h"
 #include "utils/CalamaresUtilsSystem.h"
+#include "utils/Entropy.h"
 #include "utils/Logger.h"
 
 #include <QDir>
@@ -63,41 +64,18 @@ SetPasswordJob::make_salt( int length )
     Q_ASSERT( length >= 8 );
     Q_ASSERT( length <= 128 );
 
-    static const char salt_chars[] = { '.', '/', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
-                                       'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
-                                       'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
-                                       'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' };
-
-    static_assert( sizeof( salt_chars ) == 64, "Missing salt_chars" );
-
-    std::random_device r;
-    std::seed_seq seed { r(), r(), r(), r(), r(), r(), r(), r() };
-    std::mt19937_64 twister( seed );
-
-    std::uint64_t next;
-    int current_length = 0;
-
     QString salt_string;
-    salt_string.reserve( length + 10 );
-
-    while ( current_length < length )
+    CalamaresUtils::EntropySource source = CalamaresUtils::getPrintableEntropy( length, salt_string );
+    if ( salt_string.length() != length )
     {
-        next = twister();
-        // In 64 bits, we have 10 blocks of 6 bits; map each block of 6 bits
-        // to a single salt character.
-        for ( unsigned int char_count = 0; char_count < 10; ++char_count )
-        {
-            char c = salt_chars[ next & 0b0111111 ];
-            next >>= 6;
-            salt_string.append( c );
-            if ( ++current_length >= length )
-            {
-                break;
-            }
-        }
+        cWarning() << "getPrintableEntropy returned string of length" << salt_string.length() << "expected" << length;
+        salt_string.truncate( length );
+    }
+    if ( source != CalamaresUtils::EntropySource::URandom )
+    {
+        cWarning() << "Entropy data for salt is low-quality.";
     }
 
-    salt_string.truncate( length );
     salt_string.insert( 0, "$6$" );
     salt_string.append( '$' );
     return salt_string;