diff --git a/pkgs/os-specific/darwin/apple-source-releases/default.nix b/pkgs/os-specific/darwin/apple-source-releases/default.nix
index c796ca05105..7ceeab9526c 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/default.nix
+++ b/pkgs/os-specific/darwin/apple-source-releases/default.nix
@@ -53,6 +53,7 @@ let
       ICU           = "531.48";
       libdispatch   = "442.1.4";
       Security      = "57031.40.6";
+      security_systemkeychain = "55202";
 
       IOAudioFamily                        = "203.3";
       IOFireWireFamily                     = "458";
@@ -244,6 +245,8 @@ let
     shell_cmds      = applePackage "shell_cmds"        "osx-10.11.6"     "0084k271v66h4jqp7q7rmjvv7w4mvhx3aq860qs8jbd30canm86n" {};
     system_cmds     = applePackage "system_cmds"       "osx-10.11.6"     "1h46j2c5v02pkv5d9fyv6cpgyg0lczvwicrx6r9s210cl03l77jl" {};
 
+    security_systemkeychain = applePackage "security_systemkeychain" "osx-10.10.5" "0xviskdgxsail15npi0billyiysvljlmg38mmhnr7qi4ymnnjr90" {};
+
     libsecurity_apple_csp      = libsecPackage "libsecurity_apple_csp"      "osx-10.7.5" "1ngyn1ik27n4x981px3kfd1z1n8zx7r5w812b6qfjpy5nw4h746w" {};
     libsecurity_apple_cspdl    = libsecPackage "libsecurity_apple_cspdl"    "osx-10.7.5" "1svqa5fhw7p7njzf8bzg7zgc5776aqjhdbnlhpwmr5hmz5i0x8r7" {};
     libsecurity_apple_file_dl  = libsecPackage "libsecurity_apple_file_dl"  "osx-10.7.5" "1dfqani3n135i3iqmafc1k9awmz6s0a78zifhk15rx5a8ps870bl" {};
diff --git a/pkgs/os-specific/darwin/apple-source-releases/security_systemkeychain/default.nix b/pkgs/os-specific/darwin/apple-source-releases/security_systemkeychain/default.nix
new file mode 100644
index 00000000000..1a0208ef3a0
--- /dev/null
+++ b/pkgs/os-specific/darwin/apple-source-releases/security_systemkeychain/default.nix
@@ -0,0 +1,31 @@
+{ appleDerivation, xcbuild, Security
+, libsecurity_codesigning, libsecurity_utilities, libsecurity_cdsa_utilities
+, xnu, osx_private_sdk, pcsclite}:
+
+appleDerivation {
+  buildInputs = [ xcbuild Security libsecurity_utilities
+                  libsecurity_cdsa_utilities libsecurity_codesigning
+                  pcsclite ];
+
+  NIX_LDFLAGS = "-lpcsclite";
+
+  # can't build the whole thing
+  xcbuildFlags = "-target codesign";
+
+  preBuild = ''
+    mkdir -p include/Security
+    cp ${osx_private_sdk.src}/PrivateSDK10.10.sparse.sdk/System/Library/Frameworks/Security.framework/PrivateHeaders/*.h include/Security
+    cp ${osx_private_sdk.src}/PrivateSDK10.10.sparse.sdk/System/Library/Frameworks/Security.framework/Headers/*.h include/Security
+
+    unpackFile ${xnu.src}
+    mkdir -p include/sys
+    cp -r xnu-*/bsd/sys/codesign.h include/sys/codesign.h
+  '';
+
+  NIX_CFLAGS_COMPILE = "-Iinclude";
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp Products/Release/codesign $out/bin/codesign
+  '';
+}