diff --git a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedDexFile.java b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedDexFile.java
index 8e7127a8..fe260c5f 100644
--- a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedDexFile.java
+++ b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedDexFile.java
@@ -42,11 +42,11 @@ import org.jf.dexlib2.dexbacked.reference.DexBackedTypeReference;
 import org.jf.dexlib2.dexbacked.util.FixedSizeSet;
 import org.jf.dexlib2.iface.DexFile;
 import org.jf.dexlib2.iface.reference.Reference;
+import org.jf.dexlib2.util.DexUtil;
 import org.jf.util.ExceptionWithContext;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.AbstractList;
@@ -75,7 +75,7 @@ public class DexBackedDexFile extends BaseDexBuffer implements DexFile {
         this.opcodes = opcodes;
 
         if (verifyMagic) {
-            verifyMagicAndByteOrder(buf, offset);
+            DexUtil.verifyDexHeader(buf, offset);
         }
 
         stringCount = readSmallUint(HeaderItem.STRING_COUNT_OFFSET);
@@ -107,20 +107,7 @@ public class DexBackedDexFile extends BaseDexBuffer implements DexFile {
     @Nonnull
     public static DexBackedDexFile fromInputStream(@Nonnull Opcodes opcodes, @Nonnull InputStream is)
             throws IOException {
-        if (!is.markSupported()) {
-            throw new IllegalArgumentException("InputStream must support mark");
-        }
-        is.mark(44);
-        byte[] partialHeader = new byte[44];
-        try {
-            ByteStreams.readFully(is, partialHeader);
-        } catch (EOFException ex) {
-            throw new NotADexFile("File is too short");
-        } finally {
-            is.reset();
-        }
-
-        verifyMagicAndByteOrder(partialHeader, 0);
+        DexUtil.verifyDexHeader(is);
 
         byte[] buf = ByteStreams.toByteArray(is);
         return new DexBackedDexFile(opcodes, buf, 0, false);
@@ -157,25 +144,6 @@ public class DexBackedDexFile extends BaseDexBuffer implements DexFile {
         };
     }
 
-    protected static void verifyMagicAndByteOrder(@Nonnull byte[] buf, int offset) {
-        if (!HeaderItem.verifyMagic(buf, offset)) {
-            StringBuilder sb = new StringBuilder("Invalid magic value:");
-            for (int i=0; i<8; i++) {
-                sb.append(String.format(" %02x", buf[i]));
-            }
-            throw new NotADexFile(sb.toString());
-        }
-
-        int endian = HeaderItem.getEndian(buf, offset);
-        if (endian == HeaderItem.BIG_ENDIAN_TAG) {
-            throw new ExceptionWithContext("Big endian dex files are not currently supported");
-        }
-
-        if (endian != HeaderItem.LITTLE_ENDIAN_TAG) {
-            throw new ExceptionWithContext("Invalid endian tag: 0x%x", endian);
-        }
-    }
-
     public int getStringIdItemOffset(int stringIndex) {
         if (stringIndex < 0 || stringIndex >= stringCount) {
             throw new InvalidItemIndex(stringIndex, "String index out of bounds: %d", stringIndex);
diff --git a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedOdexFile.java b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedOdexFile.java
index 12f19db0..379ecaac 100644
--- a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedOdexFile.java
+++ b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedOdexFile.java
@@ -35,9 +35,9 @@ import com.google.common.io.ByteStreams;
 import org.jf.dexlib2.Opcodes;
 import org.jf.dexlib2.dexbacked.raw.OdexHeaderItem;
 import org.jf.dexlib2.dexbacked.util.VariableSizeList;
+import org.jf.dexlib2.util.DexUtil;
 
 import javax.annotation.Nonnull;
-import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
@@ -49,7 +49,6 @@ public class DexBackedOdexFile extends DexBackedDexFile {
 
     private final byte[] odexBuf;
 
-
     public DexBackedOdexFile(@Nonnull Opcodes opcodes, @Nonnull byte[] odexBuf, byte[] dexBuf) {
         super(opcodes, dexBuf);
 
@@ -64,7 +63,7 @@ public class DexBackedOdexFile extends DexBackedDexFile {
         return true;
     }
 
-    public List<String> getDependencies() {
+    @Nonnull public List<String> getDependencies() {
         final int dexOffset = OdexHeaderItem.getDexOffset(odexBuf);
         final int dependencyOffset = OdexHeaderItem.getDependenciesOffset(odexBuf) - dexOffset;
 
@@ -85,22 +84,9 @@ public class DexBackedOdexFile extends DexBackedDexFile {
         };
     }
 
-    public static DexBackedOdexFile fromInputStream(@Nonnull Opcodes opcodes, @Nonnull InputStream is)
+    @Nonnull public static DexBackedOdexFile fromInputStream(@Nonnull Opcodes opcodes, @Nonnull InputStream is)
             throws IOException {
-        if (!is.markSupported()) {
-            throw new IllegalArgumentException("InputStream must support mark");
-        }
-        is.mark(8);
-        byte[] partialHeader = new byte[8];
-        try {
-            ByteStreams.readFully(is, partialHeader);
-        } catch (EOFException ex) {
-            throw new NotADexFile("File is too short");
-        } finally {
-            is.reset();
-        }
-
-        verifyMagic(partialHeader);
+        DexUtil.verifyOdexHeader(is);
 
         is.reset();
         byte[] odexBuf = new byte[OdexHeaderItem.ITEM_SIZE];
@@ -115,18 +101,8 @@ public class DexBackedOdexFile extends DexBackedDexFile {
         return new DexBackedOdexFile(opcodes, odexBuf, dexBuf);
     }
 
-    private static void verifyMagic(byte[] buf) {
-        if (!OdexHeaderItem.verifyMagic(buf)) {
-            StringBuilder sb = new StringBuilder("Invalid magic value:");
-            for (int i=0; i<8; i++) {
-                sb.append(String.format(" %02x", buf[i]));
-            }
-            throw new NotAnOdexFile(sb.toString());
-        }
-    }
-
     public int getOdexVersion() {
-        return OdexHeaderItem.getVersion(odexBuf);
+        return OdexHeaderItem.getVersion(odexBuf, 0);
     }
 
     public static class NotAnOdexFile extends RuntimeException {
diff --git a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/ZipDexContainer.java b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/ZipDexContainer.java
index 695866a2..97810e59 100644
--- a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/ZipDexContainer.java
+++ b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/ZipDexContainer.java
@@ -37,10 +37,12 @@ import org.jf.dexlib2.Opcodes;
 import org.jf.dexlib2.dexbacked.DexBackedDexFile.NotADexFile;
 import org.jf.dexlib2.dexbacked.ZipDexContainer.ZipDexFile;
 import org.jf.dexlib2.iface.MultiDexContainer;
+import org.jf.dexlib2.util.DexUtil;
+import org.jf.dexlib2.util.DexUtil.InvalidFile;
+import org.jf.dexlib2.util.DexUtil.UnsupportedFile;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.io.EOFException;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
@@ -49,8 +51,6 @@ import java.util.List;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
-import static org.jf.dexlib2.dexbacked.DexBackedDexFile.verifyMagicAndByteOrder;
-
 /**
  * Represents a zip file that contains dex files (i.e. an apk or jar file)
  */
@@ -154,23 +154,17 @@ public class ZipDexContainer implements MultiDexContainer<ZipDexFile> {
     protected boolean isDex(@Nonnull ZipFile zipFile, @Nonnull ZipEntry zipEntry) throws IOException {
         InputStream inputStream = zipFile.getInputStream(zipEntry);
         try {
-            inputStream.mark(44);
-            byte[] partialHeader = new byte[44];
-            try {
-                ByteStreams.readFully(inputStream, partialHeader);
-            } catch (EOFException ex) {
-                return false;
-            }
-
-            try {
-                verifyMagicAndByteOrder(partialHeader, 0);
-            } catch (NotADexFile ex) {
-                return false;
-            }
-            return true;
+            DexUtil.verifyDexHeader(inputStream);
+        } catch (NotADexFile ex) {
+            return false;
+        } catch (InvalidFile ex) {
+            return false;
+        } catch (UnsupportedFile ex) {
+            return false;
         } finally {
             inputStream.close();
         }
+        return true;
     }
 
     protected ZipFile getZipFile() throws IOException {
diff --git a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/HeaderItem.java b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/HeaderItem.java
index 531ff461..a88f509e 100644
--- a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/HeaderItem.java
+++ b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/HeaderItem.java
@@ -42,14 +42,8 @@ import javax.annotation.Nullable;
 public class HeaderItem {
     public static final int ITEM_SIZE = 0x70;
 
-    /**
-     * The magic numbers for dex files.
-     *
-     * They are: "dex\n035\0" and "dex\n037\0".
-     */
-    public static final byte[][] MAGIC_VALUES= new byte[][] {
-            new byte[]{0x64, 0x65, 0x78, 0x0a, 0x30, 0x33, 0x35, 0x00},
-            new byte[]{0x64, 0x65, 0x78, 0x0a, 0x30, 0x33, 0x37, 0x00}};
+    private static final byte[] MAGIC_VALUE = new byte[] { 0x64, 0x65, 0x78, 0x0a, 0x00, 0x00, 0x00, 0x00 };
+    private static final int[] SUPPORTED_DEX_VERSIONS = new int[] { 35, 37 };
 
     public static final int LITTLE_ENDIAN_TAG = 0x12345678;
     public static final int BIG_ENDIAN_TAG = 0x78563412;
@@ -230,48 +224,97 @@ public class HeaderItem {
         return "Invalid";
     }
 
-
     /**
-     * Get the higest magic number supported by Android for this api level.
+     * Get the highest magic number supported by Android for this api level.
      * @return The dex file magic number
      */
     public static byte[] getMagicForApi(int api) {
         if (api < 24) {
             // Prior to Android N we only support dex version 035.
-            return HeaderItem.MAGIC_VALUES[0];
+            return getMagicForDexVersion(35);
         } else {
             // On android N and later we support dex version 037.
-            return HeaderItem.MAGIC_VALUES[1];
+            return getMagicForDexVersion(37);
         }
     }
 
-    private static int getVersion(byte[] buf, int offset) {
-        if (buf.length - offset < 8) {
-            return 0;
+    public static byte[] getMagicForDexVersion(int dexVersion) {
+        byte[] magic = MAGIC_VALUE.clone();
+
+        if (dexVersion < 0 || dexVersion > 999) {
+            throw new IllegalArgumentException("dexVersion must be within [0, 999]");
         }
 
-        boolean matches = true;
-        for (int i=0; i<MAGIC_VALUES.length; i++) {
-            byte[] expected = MAGIC_VALUES[i];
-            matches = true;
-            for (int j=0; j<8; j++) {
-                if (buf[offset + j] != expected[j]) {
-                    matches = false;
-                    break;
-                }
-            }
-            if (matches) {
-                return i==0?35:37;
-            }
+        for (int i=6; i>=4; i--) {
+            int digit = dexVersion % 10;
+            magic[i] = (byte)('0' + digit);
+            dexVersion /= 10;
         }
-        return 0;
+
+        return magic;
     }
 
+    /**
+     * Verifies the magic value at the beginning of a dex file
+     *
+     * @param buf A byte array containing at least the first 8 bytes of a dex file
+     * @param offset The offset within the buffer to the beginning of the dex header
+     * @return True if the magic value is valid
+     */
     public static boolean verifyMagic(byte[] buf, int offset) {
-        // verifies the magic value
-        return getVersion(buf, offset) != 0;
+        if (buf.length - offset < 8) {
+            return false;
+        }
+
+        for (int i=0; i<4; i++) {
+            if (buf[offset + i] != MAGIC_VALUE[i]) {
+                return false;
+            }
+        }
+        for (int i=4; i<7; i++) {
+            if (buf[offset + i] < '0' ||
+                    buf[offset + i] > '9') {
+                return false;
+            }
+        }
+        if (buf[offset + 7] != MAGIC_VALUE[7]) {
+            return false;
+        }
+
+        return true;
     }
 
+    /**
+     * Gets the dex version from a dex header
+     *
+     * @param buf A byte array containing at least the first 7 bytes of a dex file
+     * @param offset The offset within the buffer to the beginning of the dex header
+     * @return The dex version if the header is valid or -1 if the header is invalid
+     */
+    public static int getVersion(byte[] buf, int offset) {
+        if (!verifyMagic(buf, offset)) {
+            return -1;
+        }
+
+        return getVersionUnchecked(buf, offset);
+    }
+
+    private static int getVersionUnchecked(byte[] buf, int offset) {
+        int version = (buf[offset + 4] - '0') * 100;
+        version += (buf[offset + 5] - '0') * 10;
+        version += buf[offset + 6] - '0';
+
+        return version;
+    }
+
+    public static boolean isSupportedDexVersion(int version) {
+        for (int i=0; i<SUPPORTED_DEX_VERSIONS.length; i++) {
+            if (SUPPORTED_DEX_VERSIONS[i] == version) {
+                return true;
+            }
+        }
+        return false;
+    }
 
     public static int getEndian(byte[] buf, int offset) {
         BaseDexBuffer bdb = new BaseDexBuffer(buf);
diff --git a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/OdexHeaderItem.java b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/OdexHeaderItem.java
index c6599bc4..7566834a 100644
--- a/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/OdexHeaderItem.java
+++ b/dexlib2/src/main/java/org/jf/dexlib2/dexbacked/raw/OdexHeaderItem.java
@@ -36,10 +36,8 @@ import org.jf.dexlib2.dexbacked.BaseDexBuffer;
 public class OdexHeaderItem {
     public static final int ITEM_SIZE = 40;
 
-    public static final byte[][] MAGIC_VALUES= new byte[][] {
-            new byte[] {0x64, 0x65, 0x79, 0x0A, 0x30, 0x33, 0x35, 0x00}, // "dey\n035\0"
-            new byte[] {0x64, 0x65, 0x79, 0x0A, 0x30, 0x33, 0x36, 0x00}  // "dey\n036\0"
-    };
+    private static final byte[] MAGIC_VALUE = new byte[] { 0x64, 0x65, 0x79, 0x0A, 0x00, 0x00, 0x00, 0x00 };
+    private static final int[] SUPPORTED_ODEX_VERSIONS = new int[] { 35, 36 };
 
     public static final int MAGIC_OFFSET = 0;
     public static final int MAGIC_LENGTH = 8;
@@ -51,31 +49,66 @@ public class OdexHeaderItem {
     public static final int AUX_LENGTH_OFFSET = 28;
     public static final int FLAGS_OFFSET = 32;
 
-    public static int getVersion(byte[] magic) {
-        if (magic.length < 8) {
-            return 0;
+    /**
+     * Verifies the magic value at the beginning of an odex file
+     *
+     * @param buf A byte array containing at least the first 8 bytes of an odex file
+     * @param offset The offset within the buffer to the beginning of the odex header
+     * @return True if the magic value is valid
+     */
+    public static boolean verifyMagic(byte[] buf, int offset) {
+        if (buf.length - offset < 8) {
+            return false;
         }
 
-        boolean matches = true;
-        for (int i=0; i<MAGIC_VALUES.length; i++) {
-            byte[] expected = MAGIC_VALUES[i];
-            matches = true;
-            for (int j=0; j<8; j++) {
-                if (magic[j] != expected[j]) {
-                    matches = false;
-                    break;
-                }
-            }
-            if (matches) {
-                return i==0?35:36;
+        for (int i=0; i<4; i++) {
+            if (buf[offset + i] != MAGIC_VALUE[i]) {
+                return false;
             }
         }
-        return 0;
+        for (int i=4; i<7; i++) {
+            if (buf[offset + i] < '0' ||
+                    buf[offset + i] > '9') {
+                return false;
+            }
+        }
+        if (buf[offset + 7] != MAGIC_VALUE[7]) {
+            return false;
+        }
+
+        return true;
     }
 
-    public static boolean verifyMagic(byte[] buf) {
-        // verifies the magic value
-        return getVersion(buf) != 0;
+    /**
+     * Gets the dex version from an odex header
+     *
+     * @param buf A byte array containing at least the first 7 bytes of an odex file
+     * @param offset The offset within the buffer to the beginning of the odex header
+     * @return The odex version if the header is valid or -1 if the header is invalid
+     */
+    public static int getVersion(byte[] buf, int offset) {
+        if (!verifyMagic(buf, offset)) {
+            return -1;
+        }
+
+        return getVersionUnchecked(buf, offset);
+    }
+
+    private static int getVersionUnchecked(byte[] buf, int offset) {
+        int version = (buf[offset + 4] - '0') * 100;
+        version += (buf[offset + 5] - '0') * 10;
+        version += buf[offset + 6] - '0';
+
+        return version;
+    }
+
+    public static boolean isSupportedOdexVersion(int version) {
+        for (int i=0; i<SUPPORTED_ODEX_VERSIONS.length; i++) {
+            if (SUPPORTED_ODEX_VERSIONS[i] == version) {
+                return true;
+            }
+        }
+        return false;
     }
 
     public static int getDexOffset(byte[] buf) {
diff --git a/dexlib2/src/main/java/org/jf/dexlib2/util/DexUtil.java b/dexlib2/src/main/java/org/jf/dexlib2/util/DexUtil.java
new file mode 100644
index 00000000..389edfd7
--- /dev/null
+++ b/dexlib2/src/main/java/org/jf/dexlib2/util/DexUtil.java
@@ -0,0 +1,189 @@
+/*
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.jf.dexlib2.util;
+
+import com.google.common.io.ByteStreams;
+import org.jf.dexlib2.dexbacked.DexBackedDexFile.NotADexFile;
+import org.jf.dexlib2.dexbacked.DexBackedOdexFile.NotAnOdexFile;
+import org.jf.dexlib2.dexbacked.raw.HeaderItem;
+import org.jf.dexlib2.dexbacked.raw.OdexHeaderItem;
+
+import javax.annotation.Nonnull;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+
+public class DexUtil {
+
+    /**
+     * Reads in the dex header from the given input stream and verifies that it is valid and a supported version
+     *
+     * The inputStream must support mark(), and will be reset to initial position upon exiting the method
+     *
+     * @param inputStream An input stream that is positioned at a dex header
+     * @throws NotADexFile If the file is not a dex file
+     * @throws InvalidFile If the header appears to be a dex file, but is not valid for some reason
+     * @throws UnsupportedFile If the dex header is valid, but uses unsupported functionality
+     */
+    public static void verifyDexHeader(@Nonnull InputStream inputStream) throws IOException {
+        if (!inputStream.markSupported()) {
+            throw new IllegalArgumentException("InputStream must support mark");
+        }
+        inputStream.mark(44);
+        byte[] partialHeader = new byte[44];
+        try {
+            ByteStreams.readFully(inputStream, partialHeader);
+        } catch (EOFException ex) {
+            throw new NotADexFile("File is too short");
+        } finally {
+            inputStream.reset();
+        }
+
+        verifyDexHeader(partialHeader, 0);
+    }
+
+    /**
+     * Verifies that the dex header is valid and a supported version
+     *
+     * @param buf A byte array containing at least the first 44 bytes of a dex file
+     * @param offset The offset within the array to the dex header
+     * @throws NotADexFile If the file is not a dex file
+     * @throws InvalidFile If the header appears to be a dex file, but is not valid for some reason
+     * @throws UnsupportedFile If the dex header is valid, but uses unsupported functionality
+     */
+    public static void verifyDexHeader(@Nonnull byte[] buf, int offset) {
+        int dexVersion = HeaderItem.getVersion(buf, offset);
+        if (dexVersion == -1) {
+            StringBuilder sb = new StringBuilder("Not a valid dex magic value:");
+            for (int i=0; i<8; i++) {
+                sb.append(String.format(" %02x", buf[i]));
+            }
+            throw new NotADexFile(sb.toString());
+        }
+
+        if (!HeaderItem.isSupportedDexVersion(dexVersion)) {
+            throw new UnsupportedFile(String.format("Dex version %03d is not supported", dexVersion));
+        }
+
+        int endian = HeaderItem.getEndian(buf, offset);
+        if (endian == HeaderItem.BIG_ENDIAN_TAG) {
+            throw new UnsupportedFile("Big endian dex files are not supported");
+        }
+
+        if (endian != HeaderItem.LITTLE_ENDIAN_TAG) {
+            throw new InvalidFile(String.format("Invalid endian tag: 0x%x", endian));
+        }
+    }
+
+    /**
+     * Reads in the odex header from the given input stream and verifies that it is valid and a supported version
+     *
+     * The inputStream must support mark(), and will be reset to initial position upon exiting the method
+     *
+     * @param inputStream An input stream that is positioned at an odex header
+     * @throws NotAnOdexFile If the file is not an odex file
+     * @throws UnsupportedFile If the odex header is valid, but is an unsupported version
+     */
+    public static void verifyOdexHeader(@Nonnull InputStream inputStream) throws IOException {
+        if (!inputStream.markSupported()) {
+            throw new IllegalArgumentException("InputStream must support mark");
+        }
+        inputStream.mark(8);
+        byte[] partialHeader = new byte[8];
+        try {
+            ByteStreams.readFully(inputStream, partialHeader);
+        } catch (EOFException ex) {
+            throw new NotAnOdexFile("File is too short");
+        } finally {
+            inputStream.reset();
+        }
+
+        verifyOdexHeader(partialHeader, 0);
+    }
+
+    /**
+     * Verifies that the odex header is valid and a supported version
+     *
+     * @param buf A byte array containing at least the first 8 bytes of an odex file
+     * @param offset The offset within the array to the odex header
+     * @throws NotAnOdexFile If the file is not an odex file
+     * @throws UnsupportedFile If the odex header is valid, but uses unsupported functionality
+     */
+    public static void verifyOdexHeader(@Nonnull byte[] buf, int offset) {
+        int odexVersion = OdexHeaderItem.getVersion(buf, offset);
+        if (odexVersion == -1) {
+            StringBuilder sb = new StringBuilder("Not a valid odex magic value:");
+            for (int i=0; i<8; i++) {
+                sb.append(String.format(" %02x", buf[i]));
+            }
+            throw new NotAnOdexFile(sb.toString());
+        }
+
+        if (!OdexHeaderItem.isSupportedOdexVersion(odexVersion)) {
+            throw new UnsupportedFile(String.format("Odex version %03d is not supported", odexVersion));
+        }
+    }
+
+    public static class InvalidFile extends RuntimeException {
+        public InvalidFile() {
+        }
+
+        public InvalidFile(String message) {
+            super(message);
+        }
+
+        public InvalidFile(String message, Throwable cause) {
+            super(message, cause);
+        }
+
+        public InvalidFile(Throwable cause) {
+            super(cause);
+        }
+    }
+
+    public static class UnsupportedFile extends RuntimeException {
+        public UnsupportedFile() {
+        }
+
+        public UnsupportedFile(String message) {
+            super(message);
+        }
+
+        public UnsupportedFile(String message, Throwable cause) {
+            super(message, cause);
+        }
+
+        public UnsupportedFile(Throwable cause) {
+            super(cause);
+        }
+    }
+}