https://tomcat.apache.org/: Common code shared by multiple Tomcat components 
public class org.apache.tomcat.util.security.ConcurrentMessageDigest
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.apache.tomcat.util.security.ConcurrentMessageDigest
  super_class: java.lang.Object
{
  private static final org.apache.tomcat.util.res.StringManager sm;
    descriptor: Lorg/apache/tomcat/util/res/StringManager;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  private static final java.lang.String MD5;
    descriptor: Ljava/lang/String;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: "MD5"

  private static final java.lang.String SHA1;
    descriptor: Ljava/lang/String;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: "SHA-1"

  private static final java.util.Map<java.lang.String, java.util.Queue<java.security.MessageDigest>> queues;
    descriptor: Ljava/util/Map;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    Signature: Ljava/util/Map<Ljava/lang/String;Ljava/util/Queue<Ljava/security/MessageDigest;>;>;

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=4, locals=1, args_size=0
         0: .line 35
            ldc Lorg/apache/tomcat/util/security/ConcurrentMessageDigest;
            invokestatic org.apache.tomcat.util.res.StringManager.getManager:(Ljava/lang/Class;)Lorg/apache/tomcat/util/res/StringManager;
            putstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.sm:Lorg/apache/tomcat/util/res/StringManager;
         1: .line 41
            new java.util.HashMap
            dup
            invokespecial java.util.HashMap.<init>:()V
         2: .line 40
            putstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.queues:Ljava/util/Map;
         3: .line 51
            ldc "MD5"
            invokestatic org.apache.tomcat.util.security.ConcurrentMessageDigest.init:(Ljava/lang/String;)V
         4: .line 52
            ldc "SHA-1"
            invokestatic org.apache.tomcat.util.security.ConcurrentMessageDigest.init:(Ljava/lang/String;)V
         5: .line 53
            goto 8
      StackMap locals:
      StackMap stack: java.security.NoSuchAlgorithmException
         6: astore 0 /* e */
        start local 0 // java.security.NoSuchAlgorithmException e
         7: .line 54
            new java.lang.IllegalArgumentException
            dup
            getstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.sm:Lorg/apache/tomcat/util/res/StringManager;
            ldc "concurrentMessageDigest.noDigest"
            invokevirtual org.apache.tomcat.util.res.StringManager.getString:(Ljava/lang/String;)Ljava/lang/String;
            aload 0 /* e */
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;Ljava/lang/Throwable;)V
            athrow
        end local 0 // java.security.NoSuchAlgorithmException e
         8: .line 56
      StackMap locals:
      StackMap stack:
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            7    8     0     e  Ljava/security/NoSuchAlgorithmException;
      Exception table:
        from    to  target  type
           3     5       6  Class java.security.NoSuchAlgorithmException

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.tomcat.util.security.ConcurrentMessageDigest this
         0: .line 44
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 46
            return
        end local 0 // org.apache.tomcat.util.security.ConcurrentMessageDigest this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/apache/tomcat/util/security/ConcurrentMessageDigest;

  public static byte[] digestMD5(byte[][]);
    descriptor: ([[B)[B
    flags: (0x0089) ACC_PUBLIC, ACC_STATIC, ACC_VARARGS
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // byte[][] input
         0: .line 59
            ldc "MD5"
            aload 0 /* input */
            invokestatic org.apache.tomcat.util.security.ConcurrentMessageDigest.digest:(Ljava/lang/String;[[B)[B
            areturn
        end local 0 // byte[][] input
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    1     0  input  [[B
    MethodParameters:
       Name  Flags
      input  

  public static byte[] digestSHA1(byte[][]);
    descriptor: ([[B)[B
    flags: (0x0089) ACC_PUBLIC, ACC_STATIC, ACC_VARARGS
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // byte[][] input
         0: .line 63
            ldc "SHA-1"
            aload 0 /* input */
            invokestatic org.apache.tomcat.util.security.ConcurrentMessageDigest.digest:(Ljava/lang/String;[[B)[B
            areturn
        end local 0 // byte[][] input
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    1     0  input  [[B
    MethodParameters:
       Name  Flags
      input  

  public static byte[] digest(java.lang.String, byte[][]);
    descriptor: (Ljava/lang/String;[[B)[B
    flags: (0x0089) ACC_PUBLIC, ACC_STATIC, ACC_VARARGS
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // java.lang.String algorithm
        start local 1 // byte[][] input
         0: .line 67
            aload 0 /* algorithm */
            iconst_1
            aload 1 /* input */
            invokestatic org.apache.tomcat.util.security.ConcurrentMessageDigest.digest:(Ljava/lang/String;I[[B)[B
            areturn
        end local 1 // byte[][] input
        end local 0 // java.lang.String algorithm
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    1     0  algorithm  Ljava/lang/String;
            0    1     1      input  [[B
    MethodParameters:
           Name  Flags
      algorithm  
      input      

  public static byte[] digest(java.lang.String, int, byte[][]);
    descriptor: (Ljava/lang/String;I[[B)[B
    flags: (0x0089) ACC_PUBLIC, ACC_STATIC, ACC_VARARGS
    Code:
      stack=4, locals=9, args_size=3
        start local 0 // java.lang.String algorithm
        start local 1 // int iterations
        start local 2 // byte[][] input
         0: .line 73
            getstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.queues:Ljava/util/Map;
            aload 0 /* algorithm */
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.util.Queue
            astore 3 /* queue */
        start local 3 // java.util.Queue queue
         1: .line 74
            aload 3 /* queue */
            ifnonnull 3
         2: .line 75
            new java.lang.IllegalStateException
            dup
            getstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.sm:Lorg/apache/tomcat/util/res/StringManager;
            ldc "concurrentMessageDigest.noDigest"
            invokevirtual org.apache.tomcat.util.res.StringManager.getString:(Ljava/lang/String;)Ljava/lang/String;
            invokespecial java.lang.IllegalStateException.<init>:(Ljava/lang/String;)V
            athrow
         3: .line 78
      StackMap locals: java.util.Queue
      StackMap stack:
            aload 3 /* queue */
            invokeinterface java.util.Queue.poll:()Ljava/lang/Object;
            checkcast java.security.MessageDigest
            astore 4 /* md */
        start local 4 // java.security.MessageDigest md
         4: .line 79
            aload 4 /* md */
            ifnonnull 9
         5: .line 81
            aload 0 /* algorithm */
            invokestatic java.security.MessageDigest.getInstance:(Ljava/lang/String;)Ljava/security/MessageDigest;
            astore 4 /* md */
         6: .line 82
            goto 9
      StackMap locals: java.lang.String int byte[][] java.util.Queue java.security.MessageDigest
      StackMap stack: java.security.NoSuchAlgorithmException
         7: astore 5 /* e */
        start local 5 // java.security.NoSuchAlgorithmException e
         8: .line 85
            new java.lang.IllegalStateException
            dup
            getstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.sm:Lorg/apache/tomcat/util/res/StringManager;
            ldc "concurrentMessageDigest.noDigest"
            invokevirtual org.apache.tomcat.util.res.StringManager.getString:(Ljava/lang/String;)Ljava/lang/String;
            aload 5 /* e */
            invokespecial java.lang.IllegalStateException.<init>:(Ljava/lang/String;Ljava/lang/Throwable;)V
            athrow
        end local 5 // java.security.NoSuchAlgorithmException e
         9: .line 90
      StackMap locals:
      StackMap stack:
            aload 2 /* input */
            dup
            astore 8
            arraylength
            istore 7
            iconst_0
            istore 6
            goto 13
      StackMap locals: java.lang.String int byte[][] java.util.Queue java.security.MessageDigest top int int byte[][]
      StackMap stack:
        10: aload 8
            iload 6
            aaload
            astore 5 /* bytes */
        start local 5 // byte[] bytes
        11: .line 91
            aload 4 /* md */
            aload 5 /* bytes */
            invokevirtual java.security.MessageDigest.update:([B)V
        end local 5 // byte[] bytes
        12: .line 90
            iinc 6 1
      StackMap locals:
      StackMap stack:
        13: iload 6
            iload 7
            if_icmplt 10
        14: .line 93
            aload 4 /* md */
            invokevirtual java.security.MessageDigest.digest:()[B
            astore 5 /* result */
        start local 5 // byte[] result
        15: .line 96
            iload 1 /* iterations */
            iconst_1
            if_icmple 22
        16: .line 97
            iconst_1
            istore 6 /* i */
        start local 6 // int i
        17: goto 21
        18: .line 98
      StackMap locals: java.lang.String int byte[][] java.util.Queue java.security.MessageDigest byte[] int
      StackMap stack:
            aload 4 /* md */
            aload 5 /* result */
            invokevirtual java.security.MessageDigest.update:([B)V
        19: .line 99
            aload 4 /* md */
            invokevirtual java.security.MessageDigest.digest:()[B
            astore 5 /* result */
        20: .line 97
            iinc 6 /* i */ 1
      StackMap locals:
      StackMap stack:
        21: iload 6 /* i */
            iload 1 /* iterations */
            if_icmplt 18
        end local 6 // int i
        22: .line 103
      StackMap locals:
      StackMap stack:
            aload 3 /* queue */
            aload 4 /* md */
            invokeinterface java.util.Queue.add:(Ljava/lang/Object;)Z
            pop
        23: .line 105
            aload 5 /* result */
            areturn
        end local 5 // byte[] result
        end local 4 // java.security.MessageDigest md
        end local 3 // java.util.Queue queue
        end local 2 // byte[][] input
        end local 1 // int iterations
        end local 0 // java.lang.String algorithm
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0   24     0   algorithm  Ljava/lang/String;
            0   24     1  iterations  I
            0   24     2       input  [[B
            1   24     3       queue  Ljava/util/Queue<Ljava/security/MessageDigest;>;
            4   24     4          md  Ljava/security/MessageDigest;
            8    9     5           e  Ljava/security/NoSuchAlgorithmException;
           11   12     5       bytes  [B
           15   24     5      result  [B
           17   22     6           i  I
      Exception table:
        from    to  target  type
           5     6       7  Class java.security.NoSuchAlgorithmException
    MethodParameters:
            Name  Flags
      algorithm   
      iterations  
      input       

  public static void init(java.lang.String);
    descriptor: (Ljava/lang/String;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=3, locals=4, args_size=1
        start local 0 // java.lang.String algorithm
         0: .line 120
            getstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.queues:Ljava/util/Map;
            dup
            astore 1
            monitorenter
         1: .line 121
            getstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.queues:Ljava/util/Map;
            aload 0 /* algorithm */
            invokeinterface java.util.Map.containsKey:(Ljava/lang/Object;)Z
            ifne 6
         2: .line 122
            aload 0 /* algorithm */
            invokestatic java.security.MessageDigest.getInstance:(Ljava/lang/String;)Ljava/security/MessageDigest;
            astore 2 /* md */
        start local 2 // java.security.MessageDigest md
         3: .line 123
            new java.util.concurrent.ConcurrentLinkedQueue
            dup
            invokespecial java.util.concurrent.ConcurrentLinkedQueue.<init>:()V
            astore 3 /* queue */
        start local 3 // java.util.Queue queue
         4: .line 124
            aload 3 /* queue */
            aload 2 /* md */
            invokeinterface java.util.Queue.add:(Ljava/lang/Object;)Z
            pop
         5: .line 125
            getstatic org.apache.tomcat.util.security.ConcurrentMessageDigest.queues:Ljava/util/Map;
            aload 0 /* algorithm */
            aload 3 /* queue */
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
        end local 3 // java.util.Queue queue
        end local 2 // java.security.MessageDigest md
         6: .line 120
      StackMap locals: java.util.Map
      StackMap stack:
            aload 1
            monitorexit
         7: goto 10
      StackMap locals:
      StackMap stack: java.lang.Throwable
         8: aload 1
            monitorexit
         9: athrow
        10: .line 128
      StackMap locals:
      StackMap stack:
            return
        end local 0 // java.lang.String algorithm
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0   11     0  algorithm  Ljava/lang/String;
            3    6     2         md  Ljava/security/MessageDigest;
            4    6     3      queue  Ljava/util/Queue<Ljava/security/MessageDigest;>;
      Exception table:
        from    to  target  type
           1     7       8  any
           8     9       8  any
    Exceptions:
      throws java.security.NoSuchAlgorithmException
    MethodParameters:
           Name  Flags
      algorithm  
}
SourceFile: "ConcurrentMessageDigest.java"