Module: Tem::ECert

Included in:
Session
Defined in:
lib/tem/ecert.rb

Instance Method Summary collapse

Instance Method Details

#emit ⇒ Object

Drives a TEM though the emitting process.



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# File 'lib/tem/ecert.rb', line 25

def emit
  emit_sec = assemble do |s|
    # Generate Endorsement Key pair, should end up in slots (0, 1).
    s.genkp :type => 0
    s.ldbc 1
    s.sub
    s.jne :to => :not_ok
    s.ldbc 0
    s.sub
    s.jne :to => :not_ok
    
    # Generate and output random authorization for PrivEK.
    s.ldbc 20
    s.dupn :n => 1
    s.outnew
    s.ldwc :privek_auth
    s.dupn :n => 2
    s.rnd
    s.outvb
    # Set authorizations for PrivEK and PubkEK.
    s.ldbc 0
    s.authk :auth => :privek_auth
    s.ldbc 1 # PubEK always has its initial authorization be all zeroes.
    s.authk :auth => :pubek_auth
    s.halt
    
    # Emitting didn't go well, return nothing and leave.
    s.label :not_ok
    s.ldbc 0
    s.outnew
    s.halt
    
    s.label :privek_auth
    s.zeros :tem_ubyte, 20
    s.label :pubek_auth
    s.zeros :tem_ubyte, 20
    s.stack 4
  end
  
  r = execute emit_sec
  if r.length == 0
    return nil
  else
    privk_auth = r[0...20]
    pubek_auth = (0...20).map {|i| 0}
    pubek = tk_read_key 1, pubek_auth
    tk_delete_key 1, pubek_auth      
    ecert = new_ecert pubek.ssl_key
    set_ecert ecert
    return { :privek_auth => privk_auth }
  end
end

#endorsement_cert ⇒ Object

Retrieves the TEM’s Endorsement Certificate.



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# File 'lib/tem/ecert.rb', line 10

def endorsement_cert
  OpenSSL::X509::Certificate.new get_tag.pack('C*')
end

#manufacturer_cert ⇒ Object

Retrieves the certificate of the TEM’s Manfacturer (CA).



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# File 'lib/tem/ecert.rb', line 15

def manufacturer_cert
  Tem::CA.ca_cert
end

#pubek ⇒ Object

Retrieves the TEM’s Public Endorsement Key.



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# File 'lib/tem/ecert.rb', line 20

def pubek
  Tem::Key.new_from_ssl_key endorsement_cert.public_key
end

#set_ecert(ecert) ⇒ Object

Writes an Endorsement Certificate to the TEM’s tag.



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# File 'lib/tem/ecert.rb', line 5

def set_ecert(ecert)
  set_tag ecert.to_der.unpack('C*')
end