Class: Kerberos::Krb5::Keytab

Inherits:
Object
  • Object
show all
Defined in:
ext/rkerberos/keytab.c

Defined Under Namespace

Classes: Exception

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#Kerberos::Krb5::Keytab.new(name: nil, context: nil) ⇒ Object

Creates and returns a new Kerberos::Krb5::Keytab object. This initializes the context and keytab for future method calls on that object.

A keytab file name may be provided. If not, the system's default keytab name is used. If a name is provided it must be in the form 'type:residual' where 'type' is a type known to the Kerberos library.

An optional context keyword argument may be provided. If given, it must be a Kerberos::Krb5::Context object and will be used instead of creating a new context via krb5_init_context.

Examples:

# Using the default keytab
keytab = Kerberos::Krb5::Keytab.new

# Using an explicit keytab
keytab = Kerberos::Krb5::Keytab.new(name: 'FILE:/etc/krb5.keytab')

# Using a custom context
ctx = Kerberos::Krb5::Context.new
keytab = Kerberos::Krb5::Keytab.new(name: 'FILE:/etc/krb5.keytab', context: ctx)


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# File 'ext/rkerberos/keytab.c', line 557

static VALUE rkrb5_keytab_initialize(int argc, VALUE* argv, VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  krb5_error_code kerror;
  char keytab_name[MAX_KEYTAB_NAME_LEN];
  VALUE v_keytab_name = Qnil;
  VALUE v_opts = Qnil;
  VALUE v_context = Qnil;
  ID kw_table[2] = { rb_intern("name"), rb_intern("context") };
  VALUE kw_vals[2];

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  rb_scan_args(argc, argv, "0:", &v_opts);

  if(NIL_P(v_opts))
    v_opts = rb_hash_new();

  rb_get_kwargs(v_opts, kw_table, 0, 2, kw_vals);
  v_keytab_name = kw_vals[0] == Qundef ? Qnil : kw_vals[0];
  v_context = kw_vals[1] == Qundef ? Qnil : kw_vals[1];

  // Initialize or borrow the context
  if(!NIL_P(v_context)){
    ptr->ctx = rkrb5_context_borrow(v_context);
    ptr->rb_context = v_context;
  }
  else{
    kerror = krb5_init_context(&ptr->ctx);

    if(kerror)
      rb_raise(cKrb5Exception, "krb5_init_context: %s", error_message(kerror));

    ptr->rb_context = Qnil;
  }

  // Use the default keytab name if one isn't provided.
  if(NIL_P(v_keytab_name)){
    kerror = krb5_kt_default_name(ptr->ctx, keytab_name, MAX_KEYTAB_NAME_LEN);

    if(kerror)
      rb_raise(cKrb5Exception, "krb5_kt_default_name: %s", error_message(kerror));

    rb_iv_set(self, "@name", rb_str_new2(keytab_name));
  }
  else{
    Check_Type(v_keytab_name, T_STRING);
    strncpy(keytab_name, StringValueCStr(v_keytab_name), MAX_KEYTAB_NAME_LEN - 1);
    keytab_name[MAX_KEYTAB_NAME_LEN - 1] = '\0';
    rb_iv_set(self, "@name", v_keytab_name);
  }

  kerror = krb5_kt_resolve(
    ptr->ctx,
    keytab_name,
    &ptr->keytab
  );

  if(kerror)
    rb_raise(cKrb5KeytabException, "krb5_kt_resolve: %s", error_message(kerror));

  return self;
}

Instance Attribute Details

#name ⇒ Object (readonly)

The name of the keytab associated with the current keytab object.

Class Method Details

.Kerberos::Krb5::Keytab.foreach(keytab = nil) ⇒ Object .entry.inspect ⇒ Object

}

Iterate over each entry in the keytab and yield a Krb5::Keytab::Entry object for each entry found.

If no keytab is provided, then the default keytab is used.



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# File 'ext/rkerberos/keytab.c', line 698

static VALUE rkrb5_s_keytab_foreach(int argc, VALUE* argv, VALUE klass){
  VALUE v_keytab_name;
  krb5_error_code kerror;
  keytab_foreach_arg fa;
  char keytab_name[MAX_KEYTAB_NAME_LEN];

  memset(&fa, 0, sizeof(fa));

  rb_scan_args(argc, argv, "01", &v_keytab_name);

  kerror = krb5_init_context(&fa.ctx);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_init_context: %s", error_message(kerror));

  // Use the default keytab name if one isn't provided.
  if(NIL_P(v_keytab_name)){
    kerror = krb5_kt_default_name(fa.ctx, keytab_name, MAX_KEYTAB_NAME_LEN);

    if(kerror){
      krb5_free_context(fa.ctx);
      rb_raise(cKrb5Exception, "krb5_kt_default_name: %s", error_message(kerror));
    }
  }
  else{
    Check_Type(v_keytab_name, T_STRING);
    strncpy(keytab_name, StringValueCStr(v_keytab_name), MAX_KEYTAB_NAME_LEN - 1);
    keytab_name[MAX_KEYTAB_NAME_LEN - 1] = '\0';
  }

  kerror = krb5_kt_resolve(fa.ctx, keytab_name, &fa.keytab);

  if(kerror){
    krb5_free_context(fa.ctx);
    rb_raise(cKrb5Exception, "krb5_kt_resolve: %s", error_message(kerror));
  }

  kerror = krb5_kt_start_seq_get(fa.ctx, fa.keytab, &fa.cursor);

  if(kerror){
    krb5_kt_close(fa.ctx, fa.keytab);
    krb5_free_context(fa.ctx);
    rb_raise(cKrb5Exception, "krb5_kt_start_seq_get: %s", error_message(kerror));
  }

  fa.cursor_active = 1;

  rb_ensure(rkrb5_s_keytab_foreach_body, (VALUE)&fa, rkrb5_s_keytab_foreach_ensure, (VALUE)&fa);

  return Qnil;
}

Instance Method Details

#add_entry(*args) ⇒ Object 



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# File 'ext/rkerberos/keytab.c', line 220

static VALUE rkrb5_keytab_add_entry(int argc, VALUE* argv, VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  krb5_error_code kerror;
  krb5_keytab_entry entry;
  krb5_data pwd_data, salt;
  VALUE v_opts, v_principal, v_password, v_vno, v_enctype;
  ID kw_table[4] = { rb_intern("principal"), rb_intern("password"), rb_intern("vno"), rb_intern("enctype") };
  VALUE kw_vals[4];

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx)
    rb_raise(cKrb5Exception, "no context has been established");

  rb_scan_args(argc, argv, "0:", &v_opts);

  if(NIL_P(v_opts))
    v_opts = rb_hash_new();

  rb_get_kwargs(v_opts, kw_table, 2, 2, kw_vals);
  v_principal = kw_vals[0];
  v_password = kw_vals[1];
  v_vno = kw_vals[2] == Qundef ? Qnil : kw_vals[2];
  v_enctype = kw_vals[3] == Qundef ? Qnil : kw_vals[3];

  Check_Type(v_principal, T_STRING);
  Check_Type(v_password, T_STRING);

  memset(&entry, 0, sizeof(entry));

  entry.vno = NIL_P(v_vno) ? 1 : NUM2INT(v_vno);
  entry.key.enctype = NIL_P(v_enctype) ? ENCTYPE_AES256_CTS_HMAC_SHA1_96 : NUM2INT(v_enctype);

  kerror = krb5_parse_name(ptr->ctx, StringValueCStr(v_principal), &entry.principal);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_parse_name: %s", error_message(kerror));

  entry.timestamp = time(NULL);

  // Derive the salt from the principal
  kerror = krb5_principal2salt(ptr->ctx, entry.principal, &salt);

  if(kerror){
    krb5_free_principal(ptr->ctx, entry.principal);
    rb_raise(cKrb5Exception, "krb5_principal2salt: %s", error_message(kerror));
  }

  // Derive key from password + salt
  pwd_data.data   = StringValuePtr(v_password);
  pwd_data.length = (unsigned int)RSTRING_LEN(v_password);

  kerror = krb5_c_string_to_key(ptr->ctx, entry.key.enctype, &pwd_data, &salt, &entry.key);

  krb5_free_data_contents(ptr->ctx, &salt);

  if(kerror){
    krb5_free_principal(ptr->ctx, entry.principal);
    rb_raise(cKrb5Exception, "krb5_c_string_to_key: %s", error_message(kerror));
  }

  kerror = krb5_kt_add_entry(ptr->ctx, ptr->keytab, &entry);

  krb5_free_keyblock_contents(ptr->ctx, &entry.key);
  krb5_free_principal(ptr->ctx, entry.principal);

  if(kerror)
    rb_raise(cKrb5KeytabException, "krb5_kt_add_entry: %s", error_message(kerror));

  return self;
}

#close ⇒ Object 



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# File 'ext/rkerberos/keytab.c', line 177

static VALUE rkrb5_keytab_close(VALUE self){
  RUBY_KRB5_KEYTAB* ptr;

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(ptr->keytab && ptr->ctx){
    krb5_kt_close(ptr->ctx, ptr->keytab);
    ptr->keytab = NULL;
  }

  if(ptr->ctx)
    krb5_free_cred_contents(ptr->ctx, &ptr->creds);

  if(ptr->ctx && ptr->rb_context == Qnil)
    krb5_free_context(ptr->ctx);
  else if(ptr->rb_context != Qnil)
    rkrb5_context_release(ptr->rb_context);

  ptr->ctx = NULL;
  ptr->rb_context = Qnil;

  return Qtrue;
}

#default_name ⇒ Object

Returns the default keytab name.



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# File 'ext/rkerberos/keytab.c', line 148

static VALUE rkrb5_keytab_default_name(VALUE self){
  char default_name[MAX_KEYTAB_NAME_LEN];
  krb5_error_code kerror;
  RUBY_KRB5_KEYTAB* ptr;
  VALUE v_default_name;

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx)
    rb_raise(cKrb5Exception, "no context has been established");

  kerror = krb5_kt_default_name(ptr->ctx, default_name, MAX_KEYTAB_NAME_LEN);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_kt_default_name: %s", error_message(kerror));

  v_default_name = rb_str_new2(default_name);

  return v_default_name;
}

#dup ⇒ Object Also known as: clone 



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# File 'ext/rkerberos/keytab.c', line 500

static VALUE rkrb5_keytab_dup(VALUE self){
  RUBY_KRB5_KEYTAB *ptr, *newptr;
  krb5_error_code kerror;
  VALUE newobj;

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx)
    rb_raise(cKrb5Exception, "no context has been established");

  newobj = rkrb5_keytab_allocate(CLASS_OF(self));
  TypedData_Get_Struct(newobj, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, newptr);

  kerror = krb5_init_context(&newptr->ctx);
  if(kerror){
    rb_raise(cKrb5Exception, "krb5_init_context: %s", error_message(kerror));
  }

  kerror = krb5_kt_dup(newptr->ctx, ptr->keytab, &newptr->keytab);
  if(kerror){
    krb5_free_context(newptr->ctx);
    newptr->ctx = NULL;
    rb_raise(cKrb5Exception, "krb5_kt_dup: %s", error_message(kerror));
  }

  rb_iv_set(newobj, "@name", rb_iv_get(self, "@name"));

  return newobj;
}

#each ⇒ Object 



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# File 'ext/rkerberos/keytab.c', line 116

static VALUE rkrb5_keytab_each(VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  krb5_error_code kerror;
  keytab_each_arg ea;

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx || !ptr->keytab)
    rb_raise(cKrb5Exception, "keytab is closed");

  ea.ctx = ptr->ctx;
  ea.keytab = ptr->keytab;

  kerror = krb5_kt_start_seq_get(ea.ctx, ea.keytab, &ea.cursor);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_kt_start_seq_get: %s", error_message(kerror));

  ea.cursor_active = 1;

  rb_ensure(rkrb5_keytab_each_body, (VALUE)&ea, rkrb5_keytab_each_ensure, (VALUE)&ea);

  return self;
}

#get_entry(*args) ⇒ Object Also known as: find 



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# File 'ext/rkerberos/keytab.c', line 389

static VALUE rkrb5_keytab_get_entry(int argc, VALUE* argv, VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  krb5_error_code kerror;
  krb5_principal principal;
  krb5_kvno vno;
  krb5_enctype enctype;
  krb5_keytab_entry entry;
  char* name;
  VALUE v_principal, v_vno, v_enctype, v_entry;

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx || !ptr->keytab)
    rb_raise(cKrb5Exception, "keytab is closed");

  rb_scan_args(argc, argv, "12", &v_principal, &v_vno, &v_enctype);

  Check_Type(v_principal, T_STRING);
  name = StringValueCStr(v_principal);

  vno = NIL_P(v_vno) ? 0 : NUM2INT(v_vno);
  enctype = NIL_P(v_enctype) ? 0 : NUM2INT(v_enctype);

  kerror = krb5_parse_name(ptr->ctx, name, &principal);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_parse_name: %s", error_message(kerror));

  kerror = krb5_kt_get_entry(
    ptr->ctx,
    ptr->keytab,
    principal,
    vno,
    enctype,
    &entry
  );

  krb5_free_principal(ptr->ctx, principal);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_kt_get_entry: %s", error_message(kerror));

  v_entry = rb_class_new_instance(0, NULL, cKrb5KtEntry);

  rb_iv_set(v_entry, "@principal", rb_str_new2(name));
  rb_iv_set(v_entry, "@timestamp", rb_time_new(entry.timestamp, 0));
  rb_iv_set(v_entry, "@vno", INT2FIX(entry.vno));
  rb_iv_set(v_entry, "@key", INT2FIX(entry.key.enctype));

  krb5_kt_free_entry(ptr->ctx, &entry);

  return v_entry;
}

#have_content? ⇒ Object 



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# File 'ext/rkerberos/keytab.c', line 756

static VALUE rkrb5_keytab_have_content(VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  krb5_error_code kerror;

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx)
    rb_raise(cKrb5Exception, "no context has been established");

  kerror = krb5_kt_have_content(ptr->ctx, ptr->keytab);

  return kerror ? Qfalse : Qtrue;
}

#keytab_name ⇒ Object 



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# File 'ext/rkerberos/keytab.c', line 451

static VALUE rkrb5_keytab_get_name(VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  krb5_error_code kerror;
  char name[MAX_KEYTAB_NAME_LEN];

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx)
    rb_raise(cKrb5Exception, "no context has been established");

  kerror = krb5_kt_get_name(ptr->ctx, ptr->keytab, name, MAX_KEYTAB_NAME_LEN);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_kt_get_name: %s", error_message(kerror));

  return rb_str_new2(name);
}

#keytab_type ⇒ Object 



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# File 'ext/rkerberos/keytab.c', line 475

static VALUE rkrb5_keytab_get_type(VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  const char *type;

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx)
    rb_raise(cKrb5Exception, "no context has been established");

  type = krb5_kt_get_type(ptr->ctx, ptr->keytab);

  if(!type)
    rb_raise(cKrb5Exception, "krb5_kt_get_type returned NULL");

  return rb_str_new2(type);
}

#remove_entry(*args) ⇒ Object 



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# File 'ext/rkerberos/keytab.c', line 312

static VALUE rkrb5_keytab_remove_entry(int argc, VALUE* argv, VALUE self){
  RUBY_KRB5_KEYTAB* ptr;
  krb5_error_code kerror;
  krb5_keytab_entry found_entry;
  krb5_principal match_princ;
  krb5_kvno match_vno;
  krb5_enctype match_enctype;
  int removed = 0;
  VALUE v_opts, v_principal, v_vno, v_enctype;
  ID kw_table[3] = { rb_intern("principal"), rb_intern("vno"), rb_intern("enctype") };
  VALUE kw_vals[3];

  TypedData_Get_Struct(self, RUBY_KRB5_KEYTAB, &rkrb5_keytab_data_type, ptr);

  if(!ptr->ctx)
    rb_raise(cKrb5Exception, "no context has been established");

  rb_scan_args(argc, argv, "0:", &v_opts);

  if(NIL_P(v_opts))
    v_opts = rb_hash_new();

  rb_get_kwargs(v_opts, kw_table, 1, 2, kw_vals);
  v_principal = kw_vals[0];
  v_vno = kw_vals[1] == Qundef ? Qnil : kw_vals[1];
  v_enctype = kw_vals[2] == Qundef ? Qnil : kw_vals[2];

  Check_Type(v_principal, T_STRING);

  match_vno = NIL_P(v_vno) ? 0 : NUM2INT(v_vno);
  match_enctype = NIL_P(v_enctype) ? 0 : NUM2INT(v_enctype);

  kerror = krb5_parse_name(ptr->ctx, StringValueCStr(v_principal), &match_princ);

  if(kerror)
    rb_raise(cKrb5Exception, "krb5_parse_name: %s", error_message(kerror));

  // Retrieve the full entry via krb5_kt_get_entry and then pass the
  // complete struct to krb5_kt_remove_entry so all fields match exactly.
  // Loop to remove every matching entry when vno/enctype are wildcards.
  while(1){
    kerror = krb5_kt_get_entry(
      ptr->ctx, ptr->keytab, match_princ,
      match_vno, match_enctype, &found_entry
    );

    if(kerror){
      krb5_free_principal(ptr->ctx, match_princ);
      if(removed)
        return self;
      rb_raise(cKrb5KeytabException, "krb5_kt_remove_entry: %s", error_message(kerror));
    }

    kerror = krb5_kt_remove_entry(ptr->ctx, ptr->keytab, &found_entry);
    krb5_kt_free_entry(ptr->ctx, &found_entry);

    if(kerror){
      krb5_free_principal(ptr->ctx, match_princ);
      rb_raise(cKrb5KeytabException, "krb5_kt_remove_entry: %s", error_message(kerror));
    }

    removed = 1;
  }
}