enhancement: support PropertyDescriptor; support flashing vbmeta.img

README.md

@@ -2,7 +2,7 @@
 [![Build Status](https://travis-ci.org/cfig/Android_boot_image_editor.svg?branch=master)](https://travis-ci.org/cfig/Android_boot_image_editor)
 [![License](http://img.shields.io/:license-apache-blue.svg?style=flat-square)](http://www.apache.org/licenses/LICENSE-2.0.html)
 
-This tool focuses on editing Android boot.img(also recovery.img and recovery-two-step.img).
+This tool focuses on editing Android boot.img(also recovery.img, recovery-two-step.img and vbmeta.img).
 
 ## Prerequisite
 #### Host OS requirement:

bbootimg/src/main/kotlin/Avb.kt

@@ -285,6 +285,9 @@ class Avb {
 
         descriptors.forEach {
             when (it) {
+                is PropertyDescriptor -> {
+                    ai.auxBlob!!.propertyDescriptor.add(it)
+                }
                 is HashDescriptor -> {
                     ai.auxBlob!!.hashDescriptors.add(it)
                 }

bbootimg/src/main/kotlin/Helper.kt

@@ -1,6 +1,5 @@
 package cfig
 
-import avb.alg.Algorithms
 import cfig.io.Struct
 import com.google.common.math.BigIntegerMath
 import org.apache.commons.codec.binary.Hex
@@ -24,6 +23,7 @@ import java.nio.file.Paths
 import java.security.KeyFactory
 import java.security.PrivateKey
 import java.security.spec.PKCS8EncodedKeySpec
+import java.security.spec.RSAPrivateKeySpec
 import java.util.zip.GZIPInputStream
 import java.util.zip.GZIPOutputStream
 import javax.crypto.Cipher
@@ -183,9 +183,7 @@ class Helper {
                     https://android.googlesource.com/platform/external/avb/+/master/libavb/avb_crypto.h#158
          */
         fun encodeRSAkey(key: ByteArray): ByteArray {
-            val p2 = PemReader(InputStreamReader(ByteArrayInputStream(key))).readPemObject()
-            Assert.assertEquals("RSA PRIVATE KEY", p2.type)
-            val rsa = RSAPrivateKey.getInstance(p2.content)
+            val rsa = KeyUtil.parsePemPrivateKey(ByteArrayInputStream(key))
             Assert.assertEquals(65537.toBigInteger(), rsa.publicExponent)
             val numBits: Int = BigIntegerMath.log2(rsa.modulus, RoundingMode.CEILING)
             log.debug("modulus: " + rsa.modulus)
@@ -213,7 +211,7 @@ class Helper {
         // "specifying Cipher.ENCRYPT mode or Cipher.DECRYPT mode doesn't make a difference;
         //      both simply perform modular exponentiation"
         fun rawSign(keyPath: String, data: ByteArray): ByteArray {
-            val privk = Helper.readPrivateKey(keyPath)
+            val privk = KeyUtil.parsePk8PrivateKey(Files.readAllBytes(Paths.get(keyPath)))
             val cipher = Cipher.getInstance("RSA/ECB/NoPadding").apply {
                 this.init(Cipher.ENCRYPT_MODE, privk)
                 this.update(data)
@@ -257,12 +255,6 @@ class Helper {
             }
         }
 
-        @Throws(Exception::class)
-        fun readPrivateKey(filename: String): PrivateKey {
-            val spec = PKCS8EncodedKeySpec(Files.readAllBytes(Paths.get(filename)))
-            return KeyFactory.getInstance("RSA").generatePrivate(spec)
-        }
-
         private val log = LoggerFactory.getLogger("Helper")
     }
 }

bbootimg/src/main/kotlin/KeyUtil.kt

@@ -0,0 +1,47 @@
+package cfig
+
+import org.bouncycastle.asn1.pkcs.RSAPrivateKey
+import org.bouncycastle.util.io.pem.PemReader
+import java.io.InputStream
+import java.io.InputStreamReader
+import java.math.BigInteger
+import java.security.KeyFactory
+import java.security.PrivateKey
+import java.security.PublicKey
+import java.security.spec.PKCS8EncodedKeySpec
+import java.security.spec.RSAPrivateKeySpec
+import java.security.spec.RSAPublicKeySpec
+
+class KeyUtil {
+    companion object {
+        @Throws(IllegalArgumentException::class)
+        fun parsePemPrivateKey(inputStream: InputStream): RSAPrivateKey {
+            val p = PemReader(InputStreamReader(inputStream)).readPemObject()
+            if ("RSA PRIVATE KEY" != p.type) {
+                throw IllegalArgumentException("input is not valid 'RSA PRIVATE KEY'")
+            }
+            return RSAPrivateKey.getInstance(p.content)
+        }
+
+        fun parsePemPrivateKey2(inputStream: InputStream): PrivateKey {
+            val rsa = KeyUtil.parsePemPrivateKey(inputStream)
+            return generateRsaPrivateKey(rsa.modulus, rsa.privateExponent)
+        }
+
+        @Throws(Exception::class)
+        fun parsePk8PrivateKey(inputData: ByteArray): PrivateKey {
+            val spec = PKCS8EncodedKeySpec(inputData)
+            return KeyFactory.getInstance("RSA").generatePrivate(spec)
+        }
+
+        @Throws(Exception::class)
+        private fun generateRsaPublicKey(modulus: BigInteger, publicExponent: BigInteger): PublicKey {
+            return KeyFactory.getInstance("RSA").generatePublic(RSAPublicKeySpec(modulus, publicExponent))
+        }
+
+        @Throws(Exception::class)
+        private fun generateRsaPrivateKey(modulus: BigInteger, privateExponent: BigInteger): PrivateKey {
+            return KeyFactory.getInstance("RSA").generatePrivate(RSAPrivateKeySpec(modulus, privateExponent))
+        }
+    }
+}

bbootimg/src/main/kotlin/avb/AVBInfo.kt

@@ -19,6 +19,7 @@ class AVBInfo(var header: Header? = null,
     data class AuxBlob(
             var pubkey: PubKeyInfo? = null,
             var pubkeyMeta: PubKeyMetadataInfo? = null,
+            var propertyDescriptor: MutableList<PropertyDescriptor> = mutableListOf(),
             var hashTreeDescriptor: MutableList<HashTreeDescriptor> = mutableListOf(),
             var hashDescriptors: MutableList<HashDescriptor> = mutableListOf(),
             var kernelCmdlineDescriptor: MutableList<KernelCmdlineDescriptor> = mutableListOf(),

bbootimg/src/main/kotlin/avb/desc/ChainPartitionDescriptor.kt

@@ -0,0 +1,10 @@
+package avb.desc
+
+class ChainPartitionDescriptor {
+    companion object {
+        const val TAG = 4L
+        const val RESERVED = 64
+        const val SIZE = 28 + RESERVED
+        const val FORMAT_STRING = "!2Q3L"
+    }
+}

bbootimg/src/main/kotlin/avb/desc/PropertyDescriptor.kt

@@ -2,18 +2,22 @@ package avb.desc
 
 import cfig.Helper
 import cfig.io.Struct
+import java.io.InputStream
 
 class PropertyDescriptor(
         var key: String = "",
         var value: String = "") : Descriptor(TAG, 0, 0) {
     override fun encode(): ByteArray {
-        this.num_bytes_following = SIZE + this.key.length + this.value.length + 2 - 16
-        val nbf_with_padding = Helper.round_to_multiple(this.num_bytes_following, 8)
-        val padding_size = nbf_with_padding - num_bytes_following
-        val padding = Struct("${padding_size}x").pack(0)
+        if (SIZE != Struct(FORMAT_STRING).calcSize()) {
+            throw RuntimeException()
+        }
+        this.num_bytes_following = SIZE + this.key.length + this.value.length + 2 - 16L
+        val nbfWithPadding = Helper.round_to_multiple(this.num_bytes_following, 8)
+        val paddingSize = nbfWithPadding - num_bytes_following
+        val padding = Struct("${paddingSize}x").pack(0)
         val desc = Struct(FORMAT_STRING).pack(
                 TAG,
-                nbf_with_padding,
+                nbfWithPadding,
                 this.key.length,
                 this.value.length)
         return Helper.join(desc,
@@ -22,9 +26,26 @@ class PropertyDescriptor(
                 padding)
     }
 
+    constructor(data: InputStream, seq: Int = 0) : this() {
+        val info = Struct(FORMAT_STRING).unpack(data)
+        this.tag = info[0] as Long
+        this.num_bytes_following = info[1] as Long
+        val keySize = info[2] as Long
+        val valueSize = info[3] as Long
+        val expectedSize = Helper.round_to_multiple(SIZE - 16 + keySize + 1 + valueSize + 1, 8)
+        if (this.tag != TAG || expectedSize != this.num_bytes_following) {
+            throw IllegalArgumentException("Given data does not look like a |property| descriptor")
+        }
+        this.sequence = seq
+
+        val info2 = Struct("${keySize}sx${valueSize}s").unpack(data)
+        this.key = String(info2[0] as ByteArray)
+        this.value = String(info2[2] as ByteArray)
+    }
+
     companion object {
-        val TAG = 0L
-        val SIZE = 32L
-        val FORMAT_STRING = "!4Q"
+        const val TAG = 0L
+        const val SIZE = 32
+        const val FORMAT_STRING = "!4Q"
     }
 }

bbootimg/src/main/kotlin/avb/desc/UnknownDescriptor.kt

@@ -32,6 +32,9 @@ class UnknownDescriptor(var data: ByteArray = byteArrayOf()) : Descriptor(0, 0,
 
     fun analyze(): Any {
         return when (this.tag) {
+            0L -> {
+                PropertyDescriptor(ByteArrayInputStream(this.encode()), this.sequence)
+            }
             1L -> {
                 HashTreeDescriptor(ByteArrayInputStream(this.encode()), this.sequence)
             }

bbootimg/src/test/kotlin/HelperTest.kt

@@ -1,9 +1,15 @@
 import avb.alg.Algorithms
 import cfig.Helper
+import cfig.KeyUtil
+import com.google.common.math.BigIntegerMath
 import org.apache.commons.codec.binary.Hex
 import org.bouncycastle.jce.provider.BouncyCastleProvider
 import org.junit.Assert.*
 import org.junit.Test
+import java.math.BigInteger
+import java.math.RoundingMode
+import java.nio.file.Files
+import java.nio.file.Paths
 import java.security.KeyFactory
 import java.security.KeyPairGenerator
 import java.security.Security
@@ -11,6 +17,11 @@ import java.security.Signature
 import java.security.spec.PKCS8EncodedKeySpec
 import java.security.spec.X509EncodedKeySpec
 import javax.crypto.Cipher
+import java.security.spec.RSAPublicKeySpec
+import java.security.PublicKey
+import java.security.spec.RSAPrivateKeySpec
+import java.security.PrivateKey
+
 
 class HelperTest {
     @Test
@@ -35,7 +46,8 @@ class HelperTest {
     fun test3() {
         val data = Hex.decodeHex("0001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff003031300d0609608648016503040201050004206317a4c8d86accc8258c1ac23ef0ebd18bc3301033")
         val signature = Signature.getInstance("NONEwithRSA")
-        val k = Helper.readPrivateKey("../" + Algorithms.get("SHA256_RSA2048")!!.defaultKey.replace("pem", "pk8"))
+        val keyFile = "../" + Algorithms.get("SHA256_RSA2048")!!.defaultKey.replace("pem", "pk8")
+        val k = KeyUtil.parsePk8PrivateKey(Files.readAllBytes(Paths.get(keyFile)))
         signature.initSign(k)
         signature.update(data)
         println("data size " + data.size)
@@ -75,4 +87,46 @@ class HelperTest {
         val encryptedText = Hex.encodeHexString(cipher.doFinal())
         println(encryptedText)
     }
+
+    @Test
+    fun testRSA() {
+//        val r = BigIntegerMath.log2(BigInteger.valueOf(1024), RoundingMode.CEILING)
+//        println(r)
+//        println(BigInteger.valueOf(1024).mod(BigInteger.valueOf(2)))
+
+        val p = BigInteger.valueOf(3)
+        val q = BigInteger.valueOf(7)
+        val modulus = p.multiply(q)
+
+        val keyLength = BigIntegerMath.log2(modulus, RoundingMode.CEILING)
+        println("keyLength = $keyLength")
+
+        //r = phi(n) = phi(p) * phi(q) = (p - 1)*(q - 1)
+        val r = (p.subtract(BigInteger.ONE)).multiply(q - BigInteger.ONE)
+
+        //r ~ e
+        //e is released as the public key exponent
+        //most commonly e = 2^16 + 1 = 65,537
+        val e = BigInteger.valueOf(5)
+
+        //(d * e).mod(r) == 1
+        //d is kept as the private key exponent
+        val d = e.modInverse(r)
+
+        println("p = $p, q = $q, modulus = $modulus , r = $r, e = $e, d = $d")
+        assertEquals(1, d.multiply(e).mod(r).toInt())
+        //private key: (modulus, d), d is calculated
+        //pub key: (modulus, e) , e is chosen
+
+        val clearMsg = BigInteger.valueOf(10)
+        val encMsg = clearMsg.pow(e.toInt()).mod(modulus)
+        println("clear: $clearMsg, enc: $encMsg")
+        val decMsg = clearMsg
+    }
+
+    fun gcd(a: BigInteger, b: BigInteger): BigInteger {
+        return if (b == BigInteger.ZERO) {
+            a
+        } else gcd(b, a.mod(b))
+    }
 }

bbootimg/src/test/kotlin/KeyUtilTest.kt

@@ -0,0 +1,21 @@
+import avb.alg.Algorithms
+import cfig.KeyUtil
+import org.apache.commons.codec.binary.Hex
+import org.junit.Assert.*
+import org.junit.Test
+import java.io.FileInputStream
+import java.nio.file.Files
+import java.nio.file.Paths
+
+class KeyUtilTest {
+    @Test
+    fun parseKeys() {
+        val keyFile = "../" + Algorithms.get("SHA256_RSA2048")!!.defaultKey
+        val k = KeyUtil.parsePk8PrivateKey(Files.readAllBytes(Paths.get(keyFile.replace("pem", "pk8"))))
+
+
+        val k2 = KeyUtil.parsePemPrivateKey2(FileInputStream(keyFile))
+        println(Hex.encodeHexString(k.encoded))
+        println(Hex.encodeHexString(k2.encoded))
+    }
+}

build.gradle

@@ -108,6 +108,12 @@ void updateBootImage(String activeImg) {
         case "recovery.img":
             flashTarget = "/dev/block/by-name/recovery";
             break;
+        case "vbmeta.img":
+            flashTarget = "/dev/block/by-name/vbmeta";
+            if (!new File(activeImg + ".signed").exists()) {
+                return;
+            }
+            break;
     }
     Run("adb root")
     Run("adb push " + activeImg + ".signed /cache/")
@@ -120,6 +126,7 @@ void updateBootImage(String activeImg) {
 task flash {
     doLast {
         updateBootImage(activeImg)
+        updateBootImage("vbmeta.img")
     }
 }