需求：仅允许安装特定签名apk，其它签名apk禁止安装。
一、移植下面代码
commit 814c25ddd422f8f44a3de9451ef25e296a298ea0
Author: shenhb <[email protected]>
Date: Thu Feb 20 11:31:19 2020 +0800
仅允许安装指定签名apk，通过属性ro.signature配置签名sha1值
index b7171ba..414a064 100755
--- a/frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -355,6 +355,7 @@ import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.zip.GZIPInputStream;
+import java.util.Locale;
/**
- Keep track of all those APKs everywhere.
@@ -18605,6 +18606,37 @@ public class PackageManagerService extends IPackageManager.Stub
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
}
-
// Add by [email protected], for only allow the specified signature apk.
-
private static String getFingerprint(Signature signature, String hashAlgorithm) {
-
if (signature == null) { -
return null; -
} -
try { -
MessageDigest digest = MessageDigest.getInstance(hashAlgorithm); -
return toHexadecimalString(digest.digest(signature.toByteArray())); -
} catch (NoSuchAlgorithmException e) { -
// ignore -
} -
return null; -
}
-
private static String toHexadecimalString(byte[] value) {
-
StringBuffer sb = new StringBuffer(); -
int len = value.length; -
for (int i = 0; i < len; i++) { -
int num = ((int) value[i]) & 0xff; -
if (num < 0x10) { -
sb.append('0'); -
} -
sb.append(Integer.toHexString(num)); -
if (i < len - 1) { -
sb.append(':'); -
} -
} -
return sb.toString().toUpperCase(Locale.US); -
}
-
// Add end
-
private void installPackageTracedLI(InstallArgs args, PackageInstalledInfo res) {
try {
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, “installPackage”);
@@ -18771,6 +18803,20 @@ public class PackageManagerService extends IPackageManager.Stub
return;
} -
// Add by [email protected], for only allow the specified signature apk. -
String customSignature = SystemProperties.get("ro.signature", ""); -
if (!TextUtils.isEmpty(customSignature)) { -
final Signature[] signatures = pkg.mSignatures; -
Slog.d(TAG, "installPackageLI, Signature fingerprint " -
+ getFingerprint(signatures[0], "SHA-1")); -
if (!getFingerprint(signatures[0], "SHA-1").equals(customSignature)) { -
res.setError(PackageManager.INSTALL_FAILED_VERIFICATION_FAILURE, -
"Signature verification failed"); -
return; -
} -
} -
// Add end -
// Get rid of all references to package scan path via parser. pp = null; String oldCodePath = null;
二、属性配置签名sha1
考虑到方案的通用性，因此通过属性来配置签名。属性不配置的情况下，走Android默认逻辑，允许安装所有apk。属性配置后，只允许跟此签名匹配的apk安装。
2.1 获取签名sha1
解压apk文件，提到META-INF/CERT.RSA（既签名文件公钥）。
执行下面命令得到公钥sha1值。
F:\download
λ keytool -printcert -file CERT.RSA
所有者: CN=xxx, OU=xxx, O=xxx, L=xxx, ST=xxx, C=china
发布者: CN=xxx, OU=xxx, O=xxx, L=xxx, ST=xxx, C=china
序列号: xxxxxxx
有效期开始日期: Sun Feb 11 14:38:48 CST 2018, 截止日期: Thu Feb 05 14:38:48 CST 2043
证书指纹:
MD5: 13:8A:22:DC:6E:6C:BA:27:42:8D:9F:C5:0D:D2:4E:14
SHA1: 31:4E:FC:8C:68:FA:7E:F4:14:E7:27:C3:A9:C4:9C:F1:AB:1C:64:C2
SHA256: 63:E0:0A:FF:45:7C:03:97:F5:27:64:C5:D4:DA:BD:8A:2E:63:40:E7:31:A3:C8:3D:FB:03:00:2A:9F:BE:71:EF
签名算法名称: SHA256withRSA
版本: 3
扩展:
#1: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier [
KeyIdentifier [
0000: C9 41 D4 8D F0 58 FF E2 EE EF 7E 5E 3B 9D DA 44 .A…X…^;…D
0010: 40 E5 DF FC @…
]
]
2.2 配置属性
ro.signature=31:4E:FC:8C:68:FA:7E:F4:14:E7:27:C3:A9:C4:9C:F1:AB:1C:64:C2
三、验证
验证结果如下，非指定签名的apk安装失败，提示“Signature verification failed”，指定签名的apk安装成功。
λ adb install 001.apk
adb: failed to install 001.apk: Failure [INSTALL_FAILED_VERIFICATION_FAILURE: Signature verification failed]
λ adb install 002.apk
Success