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Merge bitcoin/bitcoin#21045: build: adds switch to enable/disable randomized base address in MSVC builds

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9bd3f35003 build: adds switch for disabling random base addresses in MSVC (Ethan Heilman)

Pull request description:

  In m4 builds we have the --disable-hardening switch that can be given in `./configure` to turn off randomized addresses. This PR provides a simple way of turning off randomized addresses in MSVC builds.

  This PR:
  * Adds this option the common-init project file so that it can be globally set across the project
  * Documents this switch in msvc build readme

  I have run the following test to verify this works

  I ran the msvc build with `<RandomizedBaseAddress>true</RandomizedBaseAddress>` then checked `bitcoind.exe` and `bitcoin-cli.exe` with `dumpbin.exe`:

  bitcoind
  ```
  > .\dumpbin.exe /headers src/bitcoind.exe
  Microsoft (R) COFF/PE Dumper Version 14.16.27045.0
  ...
  OPTIONAL HEADER VALUES
               20B magic # (PE32+)
             14.28 linker version
            AE4600 size of code
            345C00 size of initialized data
                 0 size of uninitialized data
            6BED74 entry point (00000001406BED74) mainCRTStartup
              1000 base of code
         140000000 image base (0000000140000000 to 0000000140E2DFFF)
              1000 section alignment
               200 file alignment
              6.00 operating system version
              0.00 image version
              6.00 subsystem version
                 0 Win32 version
            E2E000 size of image
               400 size of headers
                 0 checksum
                 3 subsystem (Windows CUI)
              8160 DLL characteristics
                     High Entropy Virtual Addresses
                     Dynamic base
                     NX compatible
                     Terminal Server Aware
  ```

  bitcoin-cli
  ```
  > .\dumpbin.exe /headers src/bitcoin-cli.exe
  Microsoft (R) COFF/PE Dumper Version 14.16.27045.0
  ...
  OPTIONAL HEADER VALUES
               20B magic # (PE32+)
             14.28 linker version
            1E3E00 size of code
             92C00 size of initialized data
                 0 size of uninitialized data
            104384 entry point (0000000140104384) mainCRTStartup
              1000 base of code
         140000000 image base (0000000140000000 to 0000000140279FFF)
              1000 section alignment
               200 file alignment
              6.00 operating system version
              0.00 image version
              6.00 subsystem version
                 0 Win32 version
            27A000 size of image
               400 size of headers
                 0 checksum
                 3 subsystem (Windows CUI)
              8160 DLL characteristics
                     High Entropy Virtual Addresses
                     Dynamic base
                     NX compatible
                     Terminal Server Aware
  ```

  Then I built with `<RandomizedBaseAddress>false</RandomizedBaseAddress>` then checked `bitcoind.exe` and `bitcoin-cli.exe` with `dumpbin.exe` and observed that `Dynamic base` was longer listed in `OPTIONAL HEADER VALUES`

  bitcoind
  ```
  PS C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.16.27023\bin\HostX64\x64> .\dumpbin.exe /headers C:\Users\e0\Documents\GitHub\bitcoin021noaslr/src/bitcoind.exe
  Microsoft (R) COFF/PE Dumper Version 14.16.27045.0
  ...
  OPTIONAL HEADER VALUES
               20B magic # (PE32+)
             14.28 linker version
            AE4600 size of code
            33FE00 size of initialized data
                 0 size of uninitialized data
            6BED74 entry point (00000001406BED74) mainCRTStartup
              1000 base of code
         140000000 image base (0000000140000000 to 0000000140E27FFF)
              1000 section alignment
               200 file alignment
              6.00 operating system version
              0.00 image version
              6.00 subsystem version
                 0 Win32 version
            E28000 size of image
               400 size of headers
                 0 checksum
                 3 subsystem (Windows CUI)
              8120 DLL characteristics
                     High Entropy Virtual Addresses
                     NX compatible
                     Terminal Server Aware
  ```

  bitcoin-cli
  ```
  > .\dumpbin.exe /headers src/bitcoin-cli.exe
  Microsoft (R) COFF/PE Dumper Version 14.16.27045.0
  ...
  OPTIONAL HEADER VALUES
               20B magic # (PE32+)
             14.28 linker version
            1E3E00 size of code
             90C00 size of initialized data
                 0 size of uninitialized data
            104384 entry point (0000000140104384) mainCRTStartup
              1000 base of code
         140000000 image base (0000000140000000 to 0000000140277FFF)
              1000 section alignment
               200 file alignment
              6.00 operating system version
              0.00 image version
              6.00 subsystem version
                 0 Win32 version
            278000 size of image
               400 size of headers
                 0 checksum
                 3 subsystem (Windows CUI)
              8120 DLL characteristics
                     High Entropy Virtual Addresses
                     NX compatible
                     Terminal Server Aware
  ```

ACKs for top commit:
  sipsorcery:
    ACK 9bd3f35003.
  practicalswift:
    cr ACK 9bd3f35003: patch looks correct

Tree-SHA512: ddffdb4ff8a09c7cfef61c07a5db2a2828e9e3aa795ad8e5a1bf51ab489a68b40f87f6694518c5e0b8858c0fad4f93bb947b052e6b9d5e55eb38e764b746fc02
This commit is contained in:
W. J. van der Laan 2021-04-29 22:10:06 +02:00
commit 298fd02e4a
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GPG key ID: 1E4AED62986CD25D
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22
build_msvc/README.md
View file

@ -81,3 +81,25 @@ For safety reasons the Bitcoin Core .appveyor.yml file has the artifact options
#- 7z a bitcoin-%APPVEYOR_BUILD_VERSION%.zip %APPVEYOR_BUILD_FOLDER%\build_msvc\%platform%\%configuration%\*.exe
#- path: bitcoin-%APPVEYOR_BUILD_VERSION%.zip
```
Security
---------------------
[Base address randomization](https://docs.microsoft.com/en-us/cpp/build/reference/dynamicbase-use-address-space-layout-randomization?view=msvc-160) is used to make Bitcoin Core more secure. When building Bitcoin using the `build_msvc` process base address randomization can be disabled by editing `common.init.vcproj` to change `RandomizedBaseAddress` from `true` to `false` and then rebuilding the project.
To check if `bitcoind` has `RandomizedBaseAddress` enabled or disabled run
```
.\dumpbin.exe /headers src/bitcoind.exe
```
If is it enabled then in the output `Dynamic base` will be listed in the `DLL characteristics` under `OPTIONAL HEADER VALUES` as shown below
```
8160 DLL characteristics
High Entropy Virtual Addresses
Dynamic base
NX compatible
Terminal Server Aware
```
This may not disable all stack randomization as versions of windows employ additional stack randomization protections. These protections must be turned off in the OS configuration.

1
build_msvc/common.init.vcxproj
View file

@ -105,6 +105,7 @@
<Link>
<SubSystem>Console</SubSystem>
<AdditionalDependencies>Iphlpapi.lib;ws2_32.lib;Shlwapi.lib;kernel32.lib;user32.lib;gdi32.lib;comdlg32.lib;advapi32.lib;shell32.lib;ole32.lib;oleaut32.lib;uuid.lib;odbc32.lib;odbccp32.lib;%(AdditionalDependencies)</AdditionalDependencies>
<RandomizedBaseAddress>true</RandomizedBaseAddress>
</Link>
<Lib>
<AdditionalOptions>/ignore:4221</AdditionalOptions>