Module: Tem::Admin::Migrate

Included in:
Session
Defined in:
lib/tem/admin/migrate.rb

Overview

Logic for migrating SECpacks.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.blank_ecert_verify_seclosure ⇒ Object

Blank version of the SEClosure that verifies the destination TEM’s ECert.

The returned SEClosure is not suitable for execution. Its encrypted bytes should be replaced with the bytes from a SECpack generated with live data.



65
66
67
68
 
# File 'lib/tem/admin/migrate.rb', line 65

def self.blank_ecert_verify_seclosure
  ecert_verify_seclosure [0] * Tem::Abi.tem_ps_addr_length,
                         [0] * Tem::Abi.tem_hash_length
end

.blank_migrate_seclosure ⇒ Object

Blank version of the SEClosure that verifies the destination TEM’s ECert.

The returned SEClosure is not suitable for execution. Its encrypted bytes should be replaced with the bytes from a SECpack generated with live data.



142
143
144
145
 
# File 'lib/tem/admin/migrate.rb', line 142

def self.blank_migrate_seclosure
  migrate_seclosure [0] * Tem::Abi.tem_ps_addr_length,
                    [0] * Tem::Abi.tem_hash_length
end

.ecert_verify_bytes_tag_key ⇒ Object

The key storing the encrypted bytes of the ecert_verify SECpack in the TEM’s tag.



149
150
151
 
# File 'lib/tem/admin/migrate.rb', line 149

def self.ecert_verify_bytes_tag_key
  0x11
end

.ecert_verify_seclosure(key_ps_addr, authz) ⇒ Object

SEClosure that verifies the destination TEM’s ECert.

Args:

key_ps_addr:: the PStore address used to store the TEM key's ID
authz:: the authentication secret for the TEM's PrivEK



20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
 
# File 'lib/tem/admin/migrate.rb', line 20

def self.ecert_verify_seclosure(key_ps_addr, authz)
  Tem::Assembler.assemble { |s|
    # TODO: some actual verification, jump to :failure if it doesn't work
    
    s.ldwc :const => :pubek        
    s.rdk
    s.authk :auth => :authz
    s.stw :to => :key_id
    s.pswrfxb :addr => :pstore_addr, :from => :key_id
    s.label :success
    s.ldbc :const => 1
    s.dupn :n => 1
    s.outnew
    s.outb
    s.halt
    
    s.label :failure
    s.ldbc :const => 1
    s.outnew
    s.ldbc :const => 0
    s.outb
    s.halt
    
    s.label :key_id
    s.zeros :tem_ps_value  # Will hold the ID of the loaded PubEK.
    
    s.label :secret
    s.label :authz  # The authentication key for the PrivEK.
    s.data :tem_ubyte, authz
    s.label :pstore_addr
    s.data :tem_ps_addr, key_ps_addr
    s.label :plain
    # ARG: the target TEM's public endorsement key.
    s.label :pubek
    s.zeros :tem_ubyte, 300
    # ARG: the target TEM's endorsement certificate.
    s.label :ecert
    s.stack 10
  }
end

.migrate_bytes_tag_key ⇒ Object

The key storing the encrypted bytes of the migrate SECpack in the TEM’s tag.



154
155
156
 
# File 'lib/tem/admin/migrate.rb', line 154

def self.migrate_bytes_tag_key
  0x12
end

.migrate_seclosure(key_ps_addr, authz) ⇒ Object

SEClosure that migrates a SECpack.

Args:

key_ps_addr:: the PStore address used to store the TEM key's ID
authz:: the authentication secret for the TEM's PrivEK



75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
 
# File 'lib/tem/admin/migrate.rb', line 75

def self.migrate_seclosure(key_ps_addr, authz)
  Tem::Assembler.assemble { |s|
    s.ldbc :const => 0        # Authorize PrivEK.
    s.authk :auth => :authz
    s.dupn :n => 1             # Compute the size of the encrypted blob.
    s.ldw :from => :secpack_secret_size
    s.ldkel
    
    # Decrypt secpack.
    s.ldwc :const => :secpack_encrypted
    s.ldwc :const => :secpack_encrypted
    s.kdvb
    s.ldw :from => :secpack_secret_size  # Fail for wrong blob size.
    s.sub
    s.jnz :failure

    # Authorize target PubEK.
    s.psrdfxb :addr => :pstore_addr, :to => :key_id
    s.ldw :from => :key_id
    s.authk :auth => :authz
    
    s.dupn :n => 1  # Prepare output buffer.
    s.ldw :from => :secpack_secret_size
    s.ldkel
    s.outnew

    s.ldw :from => :secpack_secret_size  # Re-encrypt the blob.
    s.ldwc :const => :secpack_encrypted
    s.ldwc :const => -1
    s.kevb
    
    s.ldw :from => :key_id   # Clean up.
    s.relk
    s.ldbc :const => -1
    s.stw :to => :key_id
    s.pswrfxb :addr => :pstore_addr, :from => :key_id
    s.halt
    
    s.label :failure  # Communicate some failure.
    s.ldbc :const => 0
    s.outnew
    s.halt

    s.label :key_id
    s.zeros :tem_ps_value  # Will hold the ID of the loaded PubEK.
    
    s.label :secret
    s.label :authz  # The authentication key for the PrivEK.
    s.data :tem_ubyte, authz
    s.label :pstore_addr
    s.data :tem_ps_addr, key_ps_addr
    s.label :plain
    s.stack 20
    # ARG: the 'encrypted size' field in the SECpack header. 
    s.label :secpack_secret_size 
    s.zeros :tem_short, 1
    # ARG: the encrypted blob in the SECpack.
    s.label :secpack_encrypted
    s.zeros :tem_ubyte, 1
    s.label :secpack_encrypted_end
  }
end

.seclosures_from_tag_data(tem) ⇒ Object

Recovers the migration-related SECpacks from the TEM’s tag data.



178
179
180
181
182
183
184
185
186
187
188
189
190
 
# File 'lib/tem/admin/migrate.rb', line 178

def self.seclosures_from_tag_data(tem)
  tag_data = tem.tag
  
  ecert_verify = blank_ecert_verify_seclosure
  ecert_verify.fake_bind
  ecert_verify.encrypted_data = tag_data[ecert_verify_bytes_tag_key]
  
  migrate = blank_migrate_seclosure
  migrate.fake_bind
  migrate.encrypted_data = tag_data[migrate_bytes_tag_key]
  
  { :ecert_verify => ecert_verify, :migrate => migrate }
end

.tag_data(pubek, privek_authz) ⇒ Object

Data to be included in a TEM’s tag to support migration.

Returns a hash of tag key-values to be included in the TEM’s tag during emission.



162
163
164
165
166
167
168
169
170
171
172
173
174
175
 
# File 'lib/tem/admin/migrate.rb', line 162

def self.tag_data(pubek, privek_authz)
  ps_addr = OpenSSL::Random.random_bytes(Tem::Abi.tem_ps_addr_length).
      unpack('C*')
  ev_sec = ecert_verify_seclosure ps_addr, privek_authz
  ev_sec.bind pubek
  
  m_sec = migrate_seclosure ps_addr, privek_authz
  m_sec.bind pubek
  
  {
    ecert_verify_bytes_tag_key => ev_sec.encrypted_data,
    migrate_bytes_tag_key => m_sec.encrypted_data
  }
end

Instance Method Details

#migrate(secpack, ecert) ⇒ Object

Migrates a SECpack to another TEM.

Args:

secpack:: the SECpack to be migrated
ecert:: the Endorsement Certificate of the destination TEM

Returns the migrated SECpack, or nil if the Endorsement Certificate was rejected.



200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
 
# File 'lib/tem/admin/migrate.rb', line 200

def migrate(secpack, ecert)
  migrated = secpack.copy
  secpacks = Tem::Admin::Migrate.seclosures_from_tag_data self
  
  verify = secpacks[:ecert_verify]
  verify.set_bytes :pubek,
                   Tem::Key.new_from_ssl_key(ecert.public_key).to_tem_key
  return nil if execute(verify) != [1]
  
  migrate = secpacks[:migrate]
  migrate.set_value :secpack_secret_size, :tem_short, secpack.secret_bytes +
                    Tem::Abi.tem_hash_length
  migrate.set_bytes :secpack_encrypted, migrated.encrypted_data
  return nil unless new_encrypted_data = execute(migrate)
  migrated.encrypted_data = new_encrypted_data
  migrated
end