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authorW. J. van der Laan <laanwj@protonmail.com>2021-04-29 22:10:06 +0200
committerW. J. van der Laan <laanwj@protonmail.com>2021-04-29 22:14:34 +0200
commit298fd02e4a34666f049a02b63381692cde636658 (patch)
tree4254e72286bb7caa9344ee0d62aee47f365e2d8b
parent40310f5e8cd783a8114dc07224b435497bae6817 (diff)
parent9bd3f35003c2e9eff74766d57a71d6b391ab602a (diff)
Merge bitcoin/bitcoin#21045: build: adds switch to enable/disable randomized base address in MSVC builds
9bd3f35003c2e9eff74766d57a71d6b391ab602a 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 9bd3f35003c2e9eff74766d57a71d6b391ab602a. practicalswift: cr ACK 9bd3f35003c2e9eff74766d57a71d6b391ab602a: patch looks correct Tree-SHA512: ddffdb4ff8a09c7cfef61c07a5db2a2828e9e3aa795ad8e5a1bf51ab489a68b40f87f6694518c5e0b8858c0fad4f93bb947b052e6b9d5e55eb38e764b746fc02
-rw-r--r--build_msvc/README.md22
-rw-r--r--build_msvc/common.init.vcxproj1
2 files changed, 23 insertions, 0 deletions
diff --git a/build_msvc/README.md b/build_msvc/README.md
index 5ce0f6cde4..7c1704d30f 100644
--- a/build_msvc/README.md
+++ b/build_msvc/README.md
@@ -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. \ No newline at end of file
diff --git a/build_msvc/common.init.vcxproj b/build_msvc/common.init.vcxproj
index f195d3d451..6ea018d846 100644
--- a/build_msvc/common.init.vcxproj
+++ b/build_msvc/common.init.vcxproj
@@ -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>