Android签名与签名校验
一、签名方法
方法一.源码签名（android签名方法）
备注：几乎所有的自动化签名工具都是采用的这种方法
（1）生成签名所需要的keypair：公钥与私钥
build/target/product/security/mkkey.sh 来生成签名所需要的keyopenssl
pkcs8 -in $1.pem -topk8 -outform DER -out $1.pk8 -nocrypt
-subj '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com'
openssl
req -new -x509 -key $1.pem -out $1.x509.pem -days 10000 \
openssl
genrsa -3 -out $1.pem 2048
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
if ["$1" == ""]; then
echo "Create a test certificate key."
if ["$1" == ""]; then
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
openssl
genrsa -3 -out $1.pem 2048
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
openssl
genrsa -3 -out $1.pem 2048
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
openssl
req -new -x509 -key $1.pem -out $1.x509.pem -days 10000 \
openssl
genrsa -3 -out $1.pem 2048
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
-subj '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com'
openssl
req -new -x509 -key $1.pem -out $1.x509.pem -days 10000 \
openssl
genrsa -3 -out $1.pem 2048
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
-subj '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com'
openssl
req -new -x509 -key $1.pem -out $1.x509.pem -days 10000 \
openssl
genrsa -3 -out $1.pem 2048
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
openssl
pkcs8 -in $1.pem -topk8 -outform DER -out $1.pk8 -nocrypt
-subj '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com'
openssl
req -new -x509 -key $1.pem -out $1.x509.pem -days 10000 \
openssl
genrsa -3 -out $1.pem 2048
fi
return
echo "
/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"
echo "Will
generate NAME.pk8 and NAME.x509.pem"
echo "Usage: $0 NAME"
echo "Create a test certificate key."
if ["$1" == ""]; then
从脚本中，我们可以得知，是采用以下步骤生成keypair的。
root@bt:~/bubble example# openssl genrsa -3 -out test.pem 2048
Generating RSA private key, 2048 bit long modulus
...+++
...................................................................................+++
e is 3 (0x3)root@bt:~/bubble example# cat test.pem
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
root@bt:~/bubble example# openssl req -new -x509 -key test.pem -out test.x509.pem -days 10000
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:California
Locality Name (eg, city) []:Mountain View
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Android
Organizational Unit Name (eg, section) []:Android
Common Name (eg, YOUR name) []:Android
Email Address []:android@android.com
root@bt:~/bubble example# cat test.x509.pem
-----BEGIN CERTIFICATE-----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==
-----END CERTIFICATE-----
root@bt:~/bubble example# openssl pkcs8 -in test.pem -topk8 -outform DER -out test.pk8 -nocrypt（2）用keypair签名
sigapk.jar为签名工具，platform.x509.pem为公钥文件，platform.pk8为私钥文件。 网上较流行的AutoSign工具就是采用的这种方法。
#!/bin/sh
MY_SDK_HOME=~/platform/android/main/mydroid/
PEM=${MY_SDK_HOME}/build/target/product/security/platform.x509.pem
PK8=${MY_SDK_HOME}/build/target/product/security/platform.pk8
if [ $# -ne 2 ]
then
echo Usage $0 in.apk out.apk
exit 1
fi
java -jar ${MY_SDK_HOME}/out/host/linux-x86/framework/signapk.jar \
${PEM} ${PK8} $1 $2
root@bt:~/bubble example/dis# java -jar signapk.jar test.x509.pem test.pk8 unsig.apk signapk.apk数据边界与文件的开始是内存对齐的
root@bt:~/bubble example# zipalign -v 4 your_project_name-unaligned.apk your_project_name.apk方法二、命令行签名（Sun 签名方法）
工具：keytool，jarsigner
第一步：生成keystore
root@bt:~# keytool -genkey -alias dani.keystore -keyalg RSA -validity 4000 -keystore dani.keystore
oot@bt:~/bubble example/dis/FrozenBubbleSignapk/META-INF# jarsigner -keystore dani.keystore -digestalg SHA1 -sigalg MD5withRSA -signedjar signed.apk unsigend.apk dani.keystore
root@bt:~/bubble example# zipalign -v 4 your_project_name-unaligned.apk your_project_name.apk
二、签名过程分析
无论采取哪种签名方法，都会APK中生成META-INF文件夹，该文件夹包含三个文件
1. MANIFEST.MF
2.CERT.SF
3.CERT.RSA
生成过程如下：
第一步：.首先对文件夹中的文件采用sha1-base64生成摘要，将这些摘要信息保存在MANIFEST.MF中
我使用以下脚本对比了MANIFEST.MF中对应的值，符合
#!/usr/bin/perl
use Digest::SHA1 qw(sha1 sha1_hex sha1_base64);
die "$0 requires one arguments (file pathname) . \n" if $#ARGV !=0;
$filename=shift;
open FH,$filename or die "cannot open $filename";
$sha1 = Digest::SHA1->new;
$sha1->addfile(*FH);
$digest= $sha1->b64digest;
print $digest,"\n";
close FH;
第二步：.对包括MANIFEST.MF文件在内的所有文件采用sha1-base64生成摘要，方法如下。
SHA1("Name:
filename"+CR+LF+"SHA1-Digest: "+SHA1(file_content)+CR+LF+CR+LF)然后将这些摘要信息保存在CERT.MF中。
3. 对第二步中的摘要信息，采用选取的签名算法（SHA1-RSA或者MD5-RSA），用私钥进行签名，同时把公钥证书与签名信息存放在CERT.RSA中
Signature signature = Signature.getInstance("SHA1withRSA");
signature.initSign(privateKey);
je = new JarEntry(CERT_SF_NAME);
je.setTime(timestamp);
outputJar.putNextEntry(je);
writeSignatureFile(manifest,
new SignatureOutputStream(outputJar, signature));
je = new JarEntry(CERT_RSA_NAME);
je.setTime(timestamp);
outputJar.putNextEntry(je);
writeSignatureBlock(signature, publicKey, outputJar);
三、签名校验
由签名生成过程，我们可以知道签名做了两件事情：
1. 完整性校验，可以发现APK包中的文件是否存在变动。
如果对文件进行修改，对应的SHA1值会发生变动。
2.APK发布作者身份唯一性校验
当在android设备上安装apk包时，会从存放在CERT.RSA中的公钥证书中提取公钥，进行RSA解密来校验安装包的身份。
使用以下命令，可以校验APk包的签名状况
root@bt:~/bubble example/dis# jarsigner -verify -certs -verbose FrozenBubble-modify-sig.apk
4689 Wed Dec 12 15:56:44 CST 2012 META-INF/MANIFEST.MF
4810 Wed Dec 12 15:56:44 CST 2012 META-INF/DANI_KEY.SF
913 Wed Dec 12 15:56:44 CST 2012 META-INF/DANI_KEY.RSA
sm 29099 Wed Dec 12 15:10:22 CST 2012 assets/levels.txt
X.509, CN=dani lee, OU=taomee, O=taomee, L=shanghai, ST=CA, C=CA
[certificate is valid from 12/12/12 3:43 PM to 11/25/23 3:43 PM]
sm 25213 Wed Dec 12 15:20:14 CST 2012 res/drawable/app_frozen_bubble.png
使用不同的key生成的签名信息会不同，不同的私钥对应不同的公钥，因此最大的区别是签名证书中存放的公钥会不同，所以我们可以通过提取CERT.RSA中的公钥来检查安装包是否被重新签名了。
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