this will help newbees also. just adding more details to @coder_For_Life22's answer. if this answer helps you don't forget to upvote. it motivates us. for this you must already know the path of the app's keystore file and password for this example consider the key is stored at "c:\keystorekey\new.jks" 1. open this page https://code.google.com/archive/p/openssl-for-windows/downloads 2. download 32 or 64 bit zip file as per your windows OS. 3. extract the downloaded file where ever you want and remember the path. 4. for this example we consider that you have extracted the folder in download folder. so the file address will be "C:\Users\0\Downloads\openssl-0.9.8e_X64\bin\openssl.exe"; 5. now on keyboard press windows+r button. 6. this will open run box. 7. type cmd and press Ctrl+Shift+Enter. 8. this will open command prompt as administrator. 9. here navigate to java's bin folder: if you use jre provided by Android Studio you will find the path as follows: a. open android studio. b. file->project structure c. in the left pane, click 'SDK location' d. in the right pane, below 'JDK location' is your jre path. e. add "\bin" at the end of this path as the file "keytool.exe", we need, is inside this folder. for this example i consider, you have installed java separately and following is the path "C:\Program Files\Java\jre-10.0.2\bin" if you have installed 32bit java it will be in "C:\Program Files (x86)\Java\jre-10.0.2\bin" 10. now with above paths execute command as following:

keytool -exportcert -alias androiddebugkey -keystore "c:\keystorekey\new.jks" | "C:\Users\0\Downloads\openssl-0.9.8e_X64\bin\openssl.exe" sha1 -binary |"C:\Users\0\Downloads\openssl-0.9.8e_X64\bin\openssl.exe" base64

您将被要求输入密码，请输入您在创建密钥存储库密钥时所提供的密码。 ! ! 这将给你钥匙

错误: 如果你得到: --- 'keytool'不能被识别为内部或外部命令 --- 这意味着Java安装在其他地方。

这里是完整的细节(适用于Windows)

1. 根据您的32位或64位系统下载第三或第四版OpenSSl(使用e会更好)。

2. 解压到C目录下下载的zip文件

3.打开解压的文件夹到bin并复制路径，它应该是C:\openssl-0.9.8 k_x64 \bin\openssl(在结束时添加\openssl)

4. (获取Jdk bin文件夹的路径，如果你知道怎么做，忽略这个)。

打开android studio ~file~Project Structure(ctrl+alt+shift+s)，在左侧面板中选择SDK location，复制JDK位置并添加/bin

因此，最终的JDK位置将类似于C:\Program Files\Android\Android Studio\jre\bin

我们使用这种方法来获取Jdk的位置，因为你可能像我一样使用嵌入式Jdk

现在你有了OpenSSl的位置和JDK的位置

5. 现在我们需要调试密钥库的位置，为打开C~>Users~>YourUserName~>。Android应该有一个文件名调试。Keystore，复制路径位置，应该是这样的

C:\Users\Redman\.android\ debug.keystore

6. 现在打开命令提示符并键入命令

cd YourJDKLocationFromStep4  

对我来说

 cd "C:\Program Files\Android\Android Studio\jre\bin"

7. 现在构造以下命令

keytool -exportcert -alias androiddebugkey -keystore YOURKEYSTORELOCATION | YOUROPENSSLLOCATION sha1 -binary | YOUROPENSSLLOCATION base64

在我的例子中，命令如下所示

keytool -exportcert -alias androiddebugkey -keystore "C:\Users\Redman\.android\debug.keystore" | "C:\openssl-0.9.8k_X64\bin\openssl" sha1 -binary | "C:\openssl-0.9.8k_X64\bin\openssl" base64

现在在命令提示符中输入这个命令，如果你做对了，你会被要求输入密码(密码是android)

Enter keystore password:  android

就是这样，你会得到Key Hash，只是复制它并使用它

对于Signed KeyHash，构造以下命令

keytool -exportcert -alias YOUR_ALIAS_FOR_JKS -keystore YOUR_JKS_LOCATION | YOUROPENSSLLOCATION sha1 -binary | YOUROPENSSLLOCATION base64

输入您的密钥库密码，如果您输入错误的密码，它将给出错误的KeyHash

请注意

如果出于某种原因，如果它在某些路径上给出错误，那么将该路径用双引号括起来。此外，Windows power shell对我来说工作不太好，我使用git bash(或使用命令提示符)。

例子

keytool -exportcert -alias androiddebugkey -keystore "C:\Users\Redman\.android\debug.keystore" | "C:\openssl-0.9.8k_X64\bin\openssl" sha1 -binary | "C:\openssl-0.9.8k_X64\bin\openssl" base64

https://developers.facebook.com/docs/android/getting-started/

4.19.0 - 2017年1月25日

Facebook SDK

修改

Facebook SDK现在在应用程序启动时自动初始化。在大多数情况下，不再需要手动调用FacebookSDK.sdkInitialize()。有关详细信息，请参见升级指南。

为调试

try {
    PackageInfo info = getPackageManager().getPackageInfo(getPackageName(), PackageManager.GET_SIGNATURES);
    for (Signature signature : info.signatures) {
        MessageDigest md = MessageDigest.getInstance("SHA");
        md.update(signature.toByteArray());
        Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
    }
} catch (NoSuchAlgorithmException e) {
    e.printStackTrace();
} catch (Exception e) {
    e.printStackTrace();
}

Linux和Mac

开放式终端:

用于调试构建

keytool -exportcert -alias androiddebugkey -keystore debug.keystore | openssl sha1 -binary | openssl base64

你会发现调试。中的密钥存储库。android”文件夹。复制并粘贴到桌面上，然后运行上面的命令。

发布版本

keytool -exportcert -alias <aliasName> -keystore <keystoreFilePath> | openssl sha1 -binary | openssl base64

注意:确保在这两种情况下它都要求输入密码。如果它不要求输入密码，则意味着命令中有错误。调试密码。密钥存储库是“android”，为了发布，您必须输入您在创建密钥存储库时设置的密码。

请试试这个，它对我有用:

fun Context.generateSignKeyHash(): String {

    try {

        val info = packageManager.getPackageInfo(
            packageName,
            PackageManager.GET_SIGNATURES
        )

        for (signature in info.signatures) {
            val md = MessageDigest.getInstance("SHA")
            md.update(signature.toByteArray())
            return Base64.encodeToString(md.digest(), Base64.DEFAULT)
        }

    } catch (e: Exception) {
        Log.e("keyHash", e.message.toString())
    }

    return ""

}

    private fun generateKeyHash(): String? {try {
    val info =packageManager.getPackageInfo(packageName, PackageManager.GET_SIGNATURES)
    for (signature in info.signatures) {
        val md: MessageDigest = MessageDigest.getInstance("SHA")
        md.update(signature.toByteArray())
        return String(Base64.encode(md.digest(), 0))
    }
} catch (e: Exception) {
    Log.e("exception", e.toString())
}
    return "key hash not found"
}