http://www.bouncycastle.org/java.html: The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5 to JDK 1.8.
  • The Legion of the Bouncy Castle Inc. 
public class org.bouncycastle.crypto.generators.MGF1BytesGenerator implements org.bouncycastle.crypto.DerivationFunction
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.bouncycastle.crypto.generators.MGF1BytesGenerator
  super_class: java.lang.Object
{
  private org.bouncycastle.crypto.Digest digest;
    descriptor: Lorg/bouncycastle/crypto/Digest;
    flags: (0x0002) ACC_PRIVATE

  private byte[] seed;
    descriptor: [B
    flags: (0x0002) ACC_PRIVATE

  private int hLen;
    descriptor: I
    flags: (0x0002) ACC_PRIVATE

  public void <init>(org.bouncycastle.crypto.Digest);
    descriptor: (Lorg/bouncycastle/crypto/Digest;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
        start local 1 // org.bouncycastle.crypto.Digest digest
         0: .line 23
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 26
            aload 0 /* this */
            aload 1 /* digest */
            putfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
         2: .line 27
            aload 0 /* this */
            aload 1 /* digest */
            invokeinterface org.bouncycastle.crypto.Digest.getDigestSize:()I
            putfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
         3: .line 28
            return
        end local 1 // org.bouncycastle.crypto.Digest digest
        end local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    4     0    this  Lorg/bouncycastle/crypto/generators/MGF1BytesGenerator;
            0    4     1  digest  Lorg/bouncycastle/crypto/Digest;
    MethodParameters:
        Name  Flags
      digest  

  public void init(org.bouncycastle.crypto.DerivationParameters);
    descriptor: (Lorg/bouncycastle/crypto/DerivationParameters;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
        start local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
        start local 1 // org.bouncycastle.crypto.DerivationParameters param
         0: .line 33
            aload 1 /* param */
            instanceof org.bouncycastle.crypto.params.MGFParameters
            ifne 2
         1: .line 35
            new java.lang.IllegalArgumentException
            dup
            ldc "MGF parameters required for MGF1Generator"
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 38
      StackMap locals:
      StackMap stack:
            aload 1 /* param */
            checkcast org.bouncycastle.crypto.params.MGFParameters
            astore 2 /* p */
        start local 2 // org.bouncycastle.crypto.params.MGFParameters p
         3: .line 40
            aload 0 /* this */
            aload 2 /* p */
            invokevirtual org.bouncycastle.crypto.params.MGFParameters.getSeed:()[B
            putfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.seed:[B
         4: .line 41
            return
        end local 2 // org.bouncycastle.crypto.params.MGFParameters p
        end local 1 // org.bouncycastle.crypto.DerivationParameters param
        end local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    5     0   this  Lorg/bouncycastle/crypto/generators/MGF1BytesGenerator;
            0    5     1  param  Lorg/bouncycastle/crypto/DerivationParameters;
            3    5     2      p  Lorg/bouncycastle/crypto/params/MGFParameters;
    MethodParameters:
       Name  Flags
      param  

  public org.bouncycastle.crypto.Digest getDigest();
    descriptor: ()Lorg/bouncycastle/crypto/Digest;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
         0: .line 48
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            areturn
        end local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/bouncycastle/crypto/generators/MGF1BytesGenerator;

  private void ItoOSP(int, byte[]);
    descriptor: (I[B)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=4, locals=3, args_size=3
        start local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
        start local 1 // int i
        start local 2 // byte[] sp
         0: .line 58
            aload 2 /* sp */
            iconst_0
            iload 1 /* i */
            bipush 24
            iushr
            i2b
            bastore
         1: .line 59
            aload 2 /* sp */
            iconst_1
            iload 1 /* i */
            bipush 16
            iushr
            i2b
            bastore
         2: .line 60
            aload 2 /* sp */
            iconst_2
            iload 1 /* i */
            bipush 8
            iushr
            i2b
            bastore
         3: .line 61
            aload 2 /* sp */
            iconst_3
            iload 1 /* i */
            iconst_0
            iushr
            i2b
            bastore
         4: .line 62
            return
        end local 2 // byte[] sp
        end local 1 // int i
        end local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lorg/bouncycastle/crypto/generators/MGF1BytesGenerator;
            0    5     1     i  I
            0    5     2    sp  [B
    MethodParameters:
      Name  Flags
      i     
      sp    

  public int generateBytes(byte[], int, int);
    descriptor: ([BII)I
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=7, locals=7, args_size=4
        start local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
        start local 1 // byte[] out
        start local 2 // int outOff
        start local 3 // int len
         0: .line 76
            aload 1 /* out */
            arraylength
            iload 3 /* len */
            isub
            iload 2 /* outOff */
            if_icmpge 2
         1: .line 78
            new org.bouncycastle.crypto.OutputLengthException
            dup
            ldc "output buffer too small"
            invokespecial org.bouncycastle.crypto.OutputLengthException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 81
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            newarray 8
            astore 4 /* hashBuf */
        start local 4 // byte[] hashBuf
         3: .line 82
            iconst_4
            newarray 8
            astore 5 /* C */
        start local 5 // byte[] C
         4: .line 83
            iconst_0
            istore 6 /* counter */
        start local 6 // int counter
         5: .line 85
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            invokeinterface org.bouncycastle.crypto.Digest.reset:()V
         6: .line 87
            iload 3 /* len */
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            if_icmple 14
         7: .line 91
      StackMap locals: byte[] byte[] int
      StackMap stack:
            aload 0 /* this */
            iload 6 /* counter */
            aload 5 /* C */
            invokevirtual org.bouncycastle.crypto.generators.MGF1BytesGenerator.ItoOSP:(I[B)V
         8: .line 93
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.seed:[B
            iconst_0
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.seed:[B
            arraylength
            invokeinterface org.bouncycastle.crypto.Digest.update:([BII)V
         9: .line 94
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            aload 5 /* C */
            iconst_0
            aload 5 /* C */
            arraylength
            invokeinterface org.bouncycastle.crypto.Digest.update:([BII)V
        10: .line 95
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            aload 4 /* hashBuf */
            iconst_0
            invokeinterface org.bouncycastle.crypto.Digest.doFinal:([BI)I
            pop
        11: .line 97
            aload 4 /* hashBuf */
            iconst_0
            aload 1 /* out */
            iload 2 /* outOff */
            iload 6 /* counter */
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            imul
            iadd
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            invokestatic java.lang.System.arraycopy:(Ljava/lang/Object;ILjava/lang/Object;II)V
        12: .line 99
            iinc 6 /* counter */ 1
            iload 6 /* counter */
            iload 3 /* len */
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            idiv
        13: .line 89
            if_icmplt 7
        14: .line 102
      StackMap locals:
      StackMap stack:
            iload 6 /* counter */
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            imul
            iload 3 /* len */
            if_icmpge 20
        15: .line 104
            aload 0 /* this */
            iload 6 /* counter */
            aload 5 /* C */
            invokevirtual org.bouncycastle.crypto.generators.MGF1BytesGenerator.ItoOSP:(I[B)V
        16: .line 106
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.seed:[B
            iconst_0
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.seed:[B
            arraylength
            invokeinterface org.bouncycastle.crypto.Digest.update:([BII)V
        17: .line 107
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            aload 5 /* C */
            iconst_0
            aload 5 /* C */
            arraylength
            invokeinterface org.bouncycastle.crypto.Digest.update:([BII)V
        18: .line 108
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.digest:Lorg/bouncycastle/crypto/Digest;
            aload 4 /* hashBuf */
            iconst_0
            invokeinterface org.bouncycastle.crypto.Digest.doFinal:([BI)I
            pop
        19: .line 110
            aload 4 /* hashBuf */
            iconst_0
            aload 1 /* out */
            iload 2 /* outOff */
            iload 6 /* counter */
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            imul
            iadd
            iload 3 /* len */
            iload 6 /* counter */
            aload 0 /* this */
            getfield org.bouncycastle.crypto.generators.MGF1BytesGenerator.hLen:I
            imul
            isub
            invokestatic java.lang.System.arraycopy:(Ljava/lang/Object;ILjava/lang/Object;II)V
        20: .line 113
      StackMap locals:
      StackMap stack:
            iload 3 /* len */
            ireturn
        end local 6 // int counter
        end local 5 // byte[] C
        end local 4 // byte[] hashBuf
        end local 3 // int len
        end local 2 // int outOff
        end local 1 // byte[] out
        end local 0 // org.bouncycastle.crypto.generators.MGF1BytesGenerator this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0   21     0     this  Lorg/bouncycastle/crypto/generators/MGF1BytesGenerator;
            0   21     1      out  [B
            0   21     2   outOff  I
            0   21     3      len  I
            3   21     4  hashBuf  [B
            4   21     5        C  [B
            5   21     6  counter  I
    Exceptions:
      throws org.bouncycastle.crypto.DataLengthException, java.lang.IllegalArgumentException
    MethodParameters:
        Name  Flags
      out     
      outOff  
      len     
}
SourceFile: "MGF1BytesGenerator.java"