http://www.jboss.org/shrinkwrap-resolver-parent/shrinkwrap-resolver-impl-maven: Implementation for Resolving Dependencies from a Maven Backend (JBoss by Red Hat) 
public class org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter implements org.apache.maven.settings.crypto.SettingsDecrypter
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter
  super_class: java.lang.Object
{
  private org.sonatype.plexus.components.sec.dispatcher.SecDispatcher securityDispatcher;
    descriptor: Lorg/sonatype/plexus/components/sec/dispatcher/SecDispatcher;
    flags: (0x0002) ACC_PRIVATE

  public void <init>(java.io.File);
    descriptor: (Ljava/io/File;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter this
        start local 1 // java.io.File securitySettings
         0: .line 46
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 47
            aload 0 /* this */
            new org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSecurityDispatcher
            dup
            aload 1 /* securitySettings */
            invokespecial org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSecurityDispatcher.<init>:(Ljava/io/File;)V
            putfield org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter.securityDispatcher:Lorg/sonatype/plexus/components/sec/dispatcher/SecDispatcher;
         2: .line 48
            return
        end local 1 // java.io.File securitySettings
        end local 0 // org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter this
      LocalVariableTable:
        Start  End  Slot              Name  Signature
            0    3     0              this  Lorg/jboss/shrinkwrap/resolver/impl/maven/internal/decrypt/MavenSettingsDecrypter;
            0    3     1  securitySettings  Ljava/io/File;
    MethodParameters:
                  Name  Flags
      securitySettings  

  public org.apache.maven.settings.crypto.SettingsDecryptionResult decrypt(org.apache.maven.settings.crypto.SettingsDecryptionRequest);
    descriptor: (Lorg/apache/maven/settings/crypto/SettingsDecryptionRequest;)Lorg/apache/maven/settings/crypto/SettingsDecryptionResult;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=9, locals=8, args_size=2
        start local 0 // org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter this
        start local 1 // org.apache.maven.settings.crypto.SettingsDecryptionRequest request
         0: .line 51
            new java.util.ArrayList
            dup
            invokespecial java.util.ArrayList.<init>:()V
            astore 2 /* problems */
        start local 2 // java.util.List problems
         1: .line 53
            new java.util.ArrayList
            dup
            invokespecial java.util.ArrayList.<init>:()V
            astore 3 /* servers */
        start local 3 // java.util.List servers
         2: .line 55
            aload 1 /* request */
            invokeinterface org.apache.maven.settings.crypto.SettingsDecryptionRequest.getServers:()Ljava/util/List;
            invokeinterface java.util.List.iterator:()Ljava/util/Iterator;
            astore 5
            goto 18
      StackMap locals: org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter org.apache.maven.settings.crypto.SettingsDecryptionRequest java.util.List java.util.List top java.util.Iterator
      StackMap stack:
         3: aload 5
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast org.apache.maven.settings.Server
            astore 4 /* server */
        start local 4 // org.apache.maven.settings.Server server
         4: .line 56
            aload 4 /* server */
            invokevirtual org.apache.maven.settings.Server.clone:()Lorg/apache/maven/settings/Server;
            astore 4 /* server */
         5: .line 57
            aload 3 /* servers */
            aload 4 /* server */
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
         6: .line 60
            aload 4 /* server */
            aload 0 /* this */
            aload 4 /* server */
            invokevirtual org.apache.maven.settings.Server.getPassword:()Ljava/lang/String;
            invokevirtual org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter.decrypt:(Ljava/lang/String;)Ljava/lang/String;
            invokevirtual org.apache.maven.settings.Server.setPassword:(Ljava/lang/String;)V
         7: .line 61
            goto 12
      StackMap locals: org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter org.apache.maven.settings.crypto.SettingsDecryptionRequest java.util.List java.util.List org.apache.maven.settings.Server java.util.Iterator
      StackMap stack: org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException
         8: astore 6 /* e */
        start local 6 // org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException e
         9: .line 62
            aload 2 /* problems */
            new org.apache.maven.settings.building.DefaultSettingsProblem
            dup
            new java.lang.StringBuilder
            dup
            ldc "Failed to decrypt password for server "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 4 /* server */
            invokevirtual org.apache.maven.settings.Server.getId:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
        10: .line 63
            ldc ": "
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 6 /* e */
            invokevirtual org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException.getMessage:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            getstatic org.apache.maven.settings.building.SettingsProblem$Severity.ERROR:Lorg/apache/maven/settings/building/SettingsProblem$Severity;
            new java.lang.StringBuilder
            dup
            ldc "server: "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 4 /* server */
            invokevirtual org.apache.maven.settings.Server.getId:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            iconst_m1
            iconst_m1
            aload 6 /* e */
            invokespecial org.apache.maven.settings.building.DefaultSettingsProblem.<init>:(Ljava/lang/String;Lorg/apache/maven/settings/building/SettingsProblem$Severity;Ljava/lang/String;IILjava/lang/Exception;)V
        11: .line 62
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        end local 6 // org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException e
        12: .line 67
      StackMap locals:
      StackMap stack:
            aload 4 /* server */
            aload 0 /* this */
            aload 4 /* server */
            invokevirtual org.apache.maven.settings.Server.getPassphrase:()Ljava/lang/String;
            invokevirtual org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter.decrypt:(Ljava/lang/String;)Ljava/lang/String;
            invokevirtual org.apache.maven.settings.Server.setPassphrase:(Ljava/lang/String;)V
        13: .line 68
            goto 18
      StackMap locals:
      StackMap stack: org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException
        14: astore 6 /* e */
        start local 6 // org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException e
        15: .line 69
            aload 2 /* problems */
            new org.apache.maven.settings.building.DefaultSettingsProblem
            dup
            new java.lang.StringBuilder
            dup
            ldc "Failed to decrypt passphrase for server "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 4 /* server */
            invokevirtual org.apache.maven.settings.Server.getId:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
        16: .line 70
            ldc ": "
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 6 /* e */
            invokevirtual org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException.getMessage:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            getstatic org.apache.maven.settings.building.SettingsProblem$Severity.ERROR:Lorg/apache/maven/settings/building/SettingsProblem$Severity;
            new java.lang.StringBuilder
            dup
            ldc "server: "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 4 /* server */
            invokevirtual org.apache.maven.settings.Server.getId:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            iconst_m1
            iconst_m1
            aload 6 /* e */
            invokespecial org.apache.maven.settings.building.DefaultSettingsProblem.<init>:(Ljava/lang/String;Lorg/apache/maven/settings/building/SettingsProblem$Severity;Ljava/lang/String;IILjava/lang/Exception;)V
        17: .line 69
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        end local 6 // org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException e
        end local 4 // org.apache.maven.settings.Server server
        18: .line 55
      StackMap locals: org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter org.apache.maven.settings.crypto.SettingsDecryptionRequest java.util.List java.util.List top java.util.Iterator
      StackMap stack:
            aload 5
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 3
        19: .line 74
            new java.util.ArrayList
            dup
            invokespecial java.util.ArrayList.<init>:()V
            astore 4 /* proxies */
        start local 4 // java.util.List proxies
        20: .line 76
            aload 1 /* request */
            invokeinterface org.apache.maven.settings.crypto.SettingsDecryptionRequest.getProxies:()Ljava/util/List;
            invokeinterface java.util.List.iterator:()Ljava/util/Iterator;
            astore 6
            goto 30
      StackMap locals: org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter org.apache.maven.settings.crypto.SettingsDecryptionRequest java.util.List java.util.List java.util.List top java.util.Iterator
      StackMap stack:
        21: aload 6
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast org.apache.maven.settings.Proxy
            astore 5 /* proxy */
        start local 5 // org.apache.maven.settings.Proxy proxy
        22: .line 77
            aload 5 /* proxy */
            invokevirtual org.apache.maven.settings.Proxy.clone:()Lorg/apache/maven/settings/Proxy;
            astore 5 /* proxy */
        23: .line 78
            aload 4 /* proxies */
            aload 5 /* proxy */
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        24: .line 81
            aload 5 /* proxy */
            aload 0 /* this */
            aload 5 /* proxy */
            invokevirtual org.apache.maven.settings.Proxy.getPassword:()Ljava/lang/String;
            invokevirtual org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter.decrypt:(Ljava/lang/String;)Ljava/lang/String;
            invokevirtual org.apache.maven.settings.Proxy.setPassword:(Ljava/lang/String;)V
        25: .line 82
            goto 30
      StackMap locals: org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter org.apache.maven.settings.crypto.SettingsDecryptionRequest java.util.List java.util.List java.util.List org.apache.maven.settings.Proxy java.util.Iterator
      StackMap stack: org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException
        26: astore 7 /* e */
        start local 7 // org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException e
        27: .line 83
            aload 2 /* problems */
            new org.apache.maven.settings.building.DefaultSettingsProblem
            dup
            new java.lang.StringBuilder
            dup
            ldc "Failed to decrypt password for proxy "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 5 /* proxy */
            invokevirtual org.apache.maven.settings.Proxy.getId:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
        28: .line 84
            ldc ": "
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 7 /* e */
            invokevirtual org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException.getMessage:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            getstatic org.apache.maven.settings.building.SettingsProblem$Severity.ERROR:Lorg/apache/maven/settings/building/SettingsProblem$Severity;
            new java.lang.StringBuilder
            dup
            ldc "proxy: "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 5 /* proxy */
            invokevirtual org.apache.maven.settings.Proxy.getId:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            iconst_m1
            iconst_m1
            aload 7 /* e */
            invokespecial org.apache.maven.settings.building.DefaultSettingsProblem.<init>:(Ljava/lang/String;Lorg/apache/maven/settings/building/SettingsProblem$Severity;Ljava/lang/String;IILjava/lang/Exception;)V
        29: .line 83
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        end local 7 // org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException e
        end local 5 // org.apache.maven.settings.Proxy proxy
        30: .line 76
      StackMap locals: org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter org.apache.maven.settings.crypto.SettingsDecryptionRequest java.util.List java.util.List java.util.List top java.util.Iterator
      StackMap stack:
            aload 6
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 21
        31: .line 88
            new org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecryptionResult
            dup
            aload 3 /* servers */
            aload 4 /* proxies */
            aload 2 /* problems */
            invokespecial org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecryptionResult.<init>:(Ljava/util/List;Ljava/util/List;Ljava/util/List;)V
            areturn
        end local 4 // java.util.List proxies
        end local 3 // java.util.List servers
        end local 2 // java.util.List problems
        end local 1 // org.apache.maven.settings.crypto.SettingsDecryptionRequest request
        end local 0 // org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0   32     0      this  Lorg/jboss/shrinkwrap/resolver/impl/maven/internal/decrypt/MavenSettingsDecrypter;
            0   32     1   request  Lorg/apache/maven/settings/crypto/SettingsDecryptionRequest;
            1   32     2  problems  Ljava/util/List<Lorg/apache/maven/settings/building/SettingsProblem;>;
            2   32     3   servers  Ljava/util/List<Lorg/apache/maven/settings/Server;>;
            4   18     4    server  Lorg/apache/maven/settings/Server;
            9   12     6         e  Lorg/sonatype/plexus/components/sec/dispatcher/SecDispatcherException;
           15   18     6         e  Lorg/sonatype/plexus/components/sec/dispatcher/SecDispatcherException;
           20   32     4   proxies  Ljava/util/List<Lorg/apache/maven/settings/Proxy;>;
           22   30     5     proxy  Lorg/apache/maven/settings/Proxy;
           27   30     7         e  Lorg/sonatype/plexus/components/sec/dispatcher/SecDispatcherException;
      Exception table:
        from    to  target  type
           6     7       8  Class org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException
          12    13      14  Class org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException
          24    25      26  Class org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException
    MethodParameters:
         Name  Flags
      request  

  private java.lang.String decrypt(java.lang.String);
    descriptor: (Ljava/lang/String;)Ljava/lang/String;
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter this
        start local 1 // java.lang.String str
         0: .line 92
            aload 1 /* str */
            ifnonnull 1
            aconst_null
            goto 2
      StackMap locals:
      StackMap stack:
         1: aload 0 /* this */
            getfield org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter.securityDispatcher:Lorg/sonatype/plexus/components/sec/dispatcher/SecDispatcher;
            aload 1 /* str */
            invokeinterface org.sonatype.plexus.components.sec.dispatcher.SecDispatcher.decrypt:(Ljava/lang/String;)Ljava/lang/String;
      StackMap locals:
      StackMap stack: java.lang.String
         2: areturn
        end local 1 // java.lang.String str
        end local 0 // org.jboss.shrinkwrap.resolver.impl.maven.internal.decrypt.MavenSettingsDecrypter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lorg/jboss/shrinkwrap/resolver/impl/maven/internal/decrypt/MavenSettingsDecrypter;
            0    3     1   str  Ljava/lang/String;
    Exceptions:
      throws org.sonatype.plexus.components.sec.dispatcher.SecDispatcherException
    MethodParameters:
      Name  Flags
      str   
}
SourceFile: "MavenSettingsDecrypter.java"
InnerClasses:
  public final Severity = org.apache.maven.settings.building.SettingsProblem$Severity of org.apache.maven.settings.building.SettingsProblem