src/HOL/Auth/Guard/Proto.thy
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     1 (******************************************************************************
       
     2 date: april 2002
       
     3 author: Frederic Blanqui
       
     4 email: blanqui@lri.fr
       
     5 webpage: http://www.lri.fr/~blanqui/
       
     6 
       
     7 University of Cambridge, Computer Laboratory
       
     8 William Gates Building, JJ Thomson Avenue
       
     9 Cambridge CB3 0FD, United Kingdom
       
    10 ******************************************************************************)
       
    11 
       
    12 header{*Other Protocol-Independent Results*}
       
    13 
       
    14 theory Proto = Guard_Public:
       
    15 
       
    16 subsection{*protocols*}
       
    17 
       
    18 types rule = "event set * event"
       
    19 
       
    20 syntax msg' :: "rule => msg"
       
    21 
       
    22 translations "msg' R" == "msg (snd R)"
       
    23 
       
    24 types proto = "rule set"
       
    25 
       
    26 constdefs wdef :: "proto => bool"
       
    27 "wdef p == ALL R k. R:p --> Number k:parts {msg' R}
       
    28 --> Number k:parts (msg`(fst R))"
       
    29 
       
    30 subsection{*substitutions*}
       
    31 
       
    32 record subs =
       
    33   agent   :: "agent => agent"
       
    34   nonce :: "nat => nat"
       
    35   nb    :: "nat => msg"
       
    36   key   :: "key => key"
       
    37 
       
    38 consts apm :: "subs => msg => msg"
       
    39 
       
    40 primrec
       
    41 "apm s (Agent A) = Agent (agent s A)"
       
    42 "apm s (Nonce n) = Nonce (nonce s n)"
       
    43 "apm s (Number n) = nb s n"
       
    44 "apm s (Key K) = Key (key s K)"
       
    45 "apm s (Hash X) = Hash (apm s X)"
       
    46 "apm s (Crypt K X) = (
       
    47 if (EX A. K = pubK A) then Crypt (pubK (agent s (agt K))) (apm s X)
       
    48 else if (EX A. K = priK A) then Crypt (priK (agent s (agt K))) (apm s X)
       
    49 else Crypt (key s K) (apm s X))"
       
    50 "apm s {|X,Y|} = {|apm s X, apm s Y|}"
       
    51 
       
    52 lemma apm_parts: "X:parts {Y} ==> apm s X:parts {apm s Y}"
       
    53 apply (erule parts.induct, simp_all, blast)
       
    54 apply (erule parts.Fst)
       
    55 apply (erule parts.Snd)
       
    56 by (erule parts.Body)+
       
    57 
       
    58 lemma Nonce_apm [rule_format]: "Nonce n:parts {apm s X} ==>
       
    59 (ALL k. Number k:parts {X} --> Nonce n ~:parts {nb s k}) -->
       
    60 (EX k. Nonce k:parts {X} & nonce s k = n)"
       
    61 by (induct X, simp_all, blast)
       
    62 
       
    63 lemma wdef_Nonce: "[| Nonce n:parts {apm s X}; R:p; msg' R = X; wdef p;
       
    64 Nonce n ~:parts (apm s `(msg `(fst R))) |] ==>
       
    65 (EX k. Nonce k:parts {X} & nonce s k = n)"
       
    66 apply (erule Nonce_apm, unfold wdef_def)
       
    67 apply (drule_tac x=R in spec, drule_tac x=k in spec, clarsimp)
       
    68 apply (drule_tac x=x in bspec, simp)
       
    69 apply (drule_tac Y="msg x" and s=s in apm_parts, simp)
       
    70 by (blast dest: parts_parts)
       
    71 
       
    72 consts ap :: "subs => event => event"
       
    73 
       
    74 primrec
       
    75 "ap s (Says A B X) = Says (agent s A) (agent s B) (apm s X)"
       
    76 "ap s (Gets A X) = Gets (agent s A) (apm s X)"
       
    77 "ap s (Notes A X) = Notes (agent s A) (apm s X)"
       
    78 
       
    79 syntax
       
    80 ap' :: "rule => msg"
       
    81 apm' :: "rule => msg"
       
    82 priK' :: "subs => agent => key"
       
    83 pubK' :: "subs => agent => key"
       
    84 
       
    85 translations
       
    86 "ap' s R" == "ap s (snd R)"
       
    87 "apm' s R" == "apm s (msg' R)"
       
    88 "priK' s A" == "priK (agent s A)"
       
    89 "pubK' s A" == "pubK (agent s A)"
       
    90 
       
    91 subsection{*nonces generated by a rule*}
       
    92 
       
    93 constdefs newn :: "rule => nat set"
       
    94 "newn R == {n. Nonce n:parts {msg (snd R)} & Nonce n ~:parts (msg`(fst R))}"
       
    95 
       
    96 lemma newn_parts: "n:newn R ==> Nonce (nonce s n):parts {apm' s R}"
       
    97 by (auto simp: newn_def dest: apm_parts)
       
    98 
       
    99 subsection{*traces generated by a protocol*}
       
   100 
       
   101 constdefs ok :: "event list => rule => subs => bool"
       
   102 "ok evs R s == ((ALL x. x:fst R --> ap s x:set evs)
       
   103 & (ALL n. n:newn R --> Nonce (nonce s n) ~:used evs))"
       
   104 
       
   105 consts tr :: "proto => event list set"
       
   106 
       
   107 inductive "tr p" intros
       
   108 
       
   109 Nil [intro]: "[]:tr p"
       
   110 
       
   111 Fake [intro]: "[| evsf:tr p; X:synth (analz (spies evsf)) |]
       
   112 ==> Says Spy B X # evsf:tr p"
       
   113 
       
   114 Proto [intro]: "[| evs:tr p; R:p; ok evs R s |] ==> ap' s R # evs:tr p"
       
   115 
       
   116 subsection{*general properties*}
       
   117 
       
   118 lemma one_step_tr [iff]: "one_step (tr p)"
       
   119 apply (unfold one_step_def, clarify)
       
   120 by (ind_cases "ev # evs:tr p", auto)
       
   121 
       
   122 constdefs has_only_Says' :: "proto => bool"
       
   123 "has_only_Says' p == ALL R. R:p --> is_Says (snd R)"
       
   124 
       
   125 lemma has_only_Says'D: "[| R:p; has_only_Says' p |]
       
   126 ==> (EX A B X. snd R = Says A B X)"
       
   127 by (unfold has_only_Says'_def is_Says_def, blast)
       
   128 
       
   129 lemma has_only_Says_tr [simp]: "has_only_Says' p ==> has_only_Says (tr p)"
       
   130 apply (unfold has_only_Says_def)
       
   131 apply (rule allI, rule allI, rule impI)
       
   132 apply (erule tr.induct)
       
   133 apply (auto simp: has_only_Says'_def ok_def)
       
   134 by (drule_tac x=a in spec, auto simp: is_Says_def)
       
   135 
       
   136 lemma has_only_Says'_in_trD: "[| has_only_Says' p; list @ ev # evs1 \<in> tr p |]
       
   137 ==> (EX A B X. ev = Says A B X)"
       
   138 by (drule has_only_Says_tr, auto)
       
   139 
       
   140 lemma ok_not_used: "[| Nonce n ~:used evs; ok evs R s;
       
   141 ALL x. x:fst R --> is_Says x |] ==> Nonce n ~:parts (apm s `(msg `(fst R)))"
       
   142 apply (unfold ok_def, clarsimp)
       
   143 apply (drule_tac x=x in spec, drule_tac x=x in spec)
       
   144 by (auto simp: is_Says_def dest: Says_imp_spies not_used_not_spied parts_parts)
       
   145 
       
   146 lemma ok_is_Says: "[| evs' @ ev # evs:tr p; ok evs R s; has_only_Says' p;
       
   147 R:p; x:fst R |] ==> is_Says x"
       
   148 apply (unfold ok_def is_Says_def, clarify)
       
   149 apply (drule_tac x=x in spec, simp)
       
   150 apply (subgoal_tac "one_step (tr p)")
       
   151 apply (drule trunc, simp, drule one_step_Cons, simp)
       
   152 apply (drule has_only_SaysD, simp+)
       
   153 by (clarify, case_tac x, auto)
       
   154 
       
   155 subsection{*types*}
       
   156 
       
   157 types keyfun = "rule => subs => nat => event list => key set"
       
   158 
       
   159 types secfun = "rule => nat => subs => key set => msg"
       
   160 
       
   161 subsection{*introduction of a fresh guarded nonce*}
       
   162 
       
   163 constdefs fresh :: "proto => rule => subs => nat => key set => event list
       
   164 => bool"
       
   165 "fresh p R s n Ks evs == (EX evs1 evs2. evs = evs2 @ ap' s R # evs1
       
   166 & Nonce n ~:used evs1 & R:p & ok evs1 R s & Nonce n:parts {apm' s R}
       
   167 & apm' s R:guard n Ks)"
       
   168 
       
   169 lemma freshD: "fresh p R s n Ks evs ==> (EX evs1 evs2.
       
   170 evs = evs2 @ ap' s R # evs1 & Nonce n ~:used evs1 & R:p & ok evs1 R s
       
   171 & Nonce n:parts {apm' s R} & apm' s R:guard n Ks)"
       
   172 by (unfold fresh_def, blast)
       
   173 
       
   174 lemma freshI [intro]: "[| Nonce n ~:used evs1; R:p; Nonce n:parts {apm' s R};
       
   175 ok evs1 R s; apm' s R:guard n Ks |]
       
   176 ==> fresh p R s n Ks (list @ ap' s R # evs1)"
       
   177 by (unfold fresh_def, blast)
       
   178 
       
   179 lemma freshI': "[| Nonce n ~:used evs1; (l,r):p;
       
   180 Nonce n:parts {apm s (msg r)}; ok evs1 (l,r) s; apm s (msg r):guard n Ks |]
       
   181 ==> fresh p (l,r) s n Ks (evs2 @ ap s r # evs1)"
       
   182 by (drule freshI, simp+)
       
   183 
       
   184 lemma fresh_used: "[| fresh p R' s' n Ks evs; has_only_Says' p |]
       
   185 ==> Nonce n:used evs"
       
   186 apply (unfold fresh_def, clarify)
       
   187 apply (drule has_only_Says'D)
       
   188 by (auto intro: parts_used_app)
       
   189 
       
   190 lemma fresh_newn: "[| evs' @ ap' s R # evs:tr p; wdef p; has_only_Says' p;
       
   191 Nonce n ~:used evs; R:p; ok evs R s; Nonce n:parts {apm' s R} |]
       
   192 ==> EX k. k:newn R & nonce s k = n"
       
   193 apply (drule wdef_Nonce, simp+)
       
   194 apply (frule ok_not_used, simp+)
       
   195 apply (clarify, erule ok_is_Says, simp+)
       
   196 apply (clarify, rule_tac x=k in exI, simp add: newn_def)
       
   197 apply (clarify, drule_tac Y="msg x" and s=s in apm_parts)
       
   198 apply (drule ok_not_used, simp+)
       
   199 apply (clarify, erule ok_is_Says, simp+)
       
   200 by blast
       
   201 
       
   202 lemma fresh_rule: "[| evs' @ ev # evs:tr p; wdef p; Nonce n ~:used evs;
       
   203 Nonce n:parts {msg ev} |] ==> EX R s. R:p & ap' s R = ev"
       
   204 apply (drule trunc, simp, ind_cases "ev # evs:tr p", simp)
       
   205 by (drule_tac x=X in in_sub, drule parts_sub, simp, simp, blast+)
       
   206 
       
   207 lemma fresh_ruleD: "[| fresh p R' s' n Ks evs; keys R' s' n evs <= Ks; wdef p;
       
   208 has_only_Says' p; evs:tr p; ALL R k s. nonce s k = n --> Nonce n:used evs -->
       
   209 R:p --> k:newn R --> Nonce n:parts {apm' s R} --> apm' s R:guard n Ks -->
       
   210 apm' s R:parts (spies evs) --> keys R s n evs <= Ks --> P |] ==> P"
       
   211 apply (frule fresh_used, simp)
       
   212 apply (unfold fresh_def, clarify)
       
   213 apply (drule_tac x=R' in spec)
       
   214 apply (drule fresh_newn, simp+, clarify)
       
   215 apply (drule_tac x=k in spec)
       
   216 apply (drule_tac x=s' in spec)
       
   217 apply (subgoal_tac "apm' s' R':parts (spies (evs2 @ ap' s' R' # evs1))")
       
   218 apply (case_tac R', drule has_only_Says'D, simp, clarsimp)
       
   219 apply (case_tac R', drule has_only_Says'D, simp, clarsimp)
       
   220 apply (rule_tac Y="apm s' X" in parts_parts, blast)
       
   221 by (rule parts.Inj, rule Says_imp_spies, simp, blast)
       
   222 
       
   223 subsection{*safe keys*}
       
   224 
       
   225 constdefs safe :: "key set => msg set => bool"
       
   226 "safe Ks G == ALL K. K:Ks --> Key K ~:analz G"
       
   227 
       
   228 lemma safeD [dest]: "[| safe Ks G; K:Ks |] ==> Key K ~:analz G"
       
   229 by (unfold safe_def, blast)
       
   230 
       
   231 lemma safe_insert: "safe Ks (insert X G) ==> safe Ks G"
       
   232 by (unfold safe_def, blast)
       
   233 
       
   234 lemma Guard_safe: "[| Guard n Ks G; safe Ks G |] ==> Nonce n ~:analz G"
       
   235 by (blast dest: Guard_invKey)
       
   236 
       
   237 subsection{*guardedness preservation*}
       
   238 
       
   239 constdefs preserv :: "proto => keyfun => nat => key set => bool"
       
   240 "preserv p keys n Ks == (ALL evs R' s' R s. evs:tr p -->
       
   241 Guard n Ks (spies evs) --> safe Ks (spies evs) --> fresh p R' s' n Ks evs -->
       
   242 keys R' s' n evs <= Ks --> R:p --> ok evs R s --> apm' s R:guard n Ks)"
       
   243 
       
   244 lemma preservD: "[| preserv p keys n Ks; evs:tr p; Guard n Ks (spies evs);
       
   245 safe Ks (spies evs); fresh p R' s' n Ks evs; R:p; ok evs R s;
       
   246 keys R' s' n evs <= Ks |] ==> apm' s R:guard n Ks"
       
   247 by (unfold preserv_def, blast)
       
   248 
       
   249 lemma preservD': "[| preserv p keys n Ks; evs:tr p; Guard n Ks (spies evs);
       
   250 safe Ks (spies evs); fresh p R' s' n Ks evs; (l,Says A B X):p;
       
   251 ok evs (l,Says A B X) s; keys R' s' n evs <= Ks |] ==> apm s X:guard n Ks"
       
   252 by (drule preservD, simp+)
       
   253 
       
   254 subsection{*monotonic keyfun*}
       
   255 
       
   256 constdefs monoton :: "proto => keyfun => bool"
       
   257 "monoton p keys == ALL R' s' n ev evs. ev # evs:tr p -->
       
   258 keys R' s' n evs <= keys R' s' n (ev # evs)"
       
   259 
       
   260 lemma monotonD [dest]: "[| keys R' s' n (ev # evs) <= Ks; monoton p keys;
       
   261 ev # evs:tr p |] ==> keys R' s' n evs <= Ks"
       
   262 by (unfold monoton_def, blast)
       
   263 
       
   264 subsection{*guardedness theorem*}
       
   265 
       
   266 lemma Guard_tr [rule_format]: "[| evs:tr p; has_only_Says' p;
       
   267 preserv p keys n Ks; monoton p keys; Guard n Ks (initState Spy) |] ==>
       
   268 safe Ks (spies evs) --> fresh p R' s' n Ks evs --> keys R' s' n evs <= Ks -->
       
   269 Guard n Ks (spies evs)"
       
   270 apply (erule tr.induct)
       
   271 (* Nil *)
       
   272 apply simp
       
   273 (* Fake *)
       
   274 apply (clarify, drule freshD, clarsimp)
       
   275 apply (case_tac evs2)
       
   276 (* evs2 = [] *)
       
   277 apply (frule has_only_Says'D, simp)
       
   278 apply (clarsimp, blast)
       
   279 (* evs2 = aa # list *)
       
   280 apply (clarsimp, rule conjI)
       
   281 apply (blast dest: safe_insert)
       
   282 (* X:guard n Ks *)
       
   283 apply (rule in_synth_Guard, simp, rule Guard_analz)
       
   284 apply (blast dest: safe_insert)
       
   285 apply (drule safe_insert, simp add: safe_def)
       
   286 (* Proto *)
       
   287 apply (clarify, drule freshD, clarify)
       
   288 apply (case_tac evs2)
       
   289 (* evs2 = [] *)
       
   290 apply (frule has_only_Says'D, simp)
       
   291 apply (frule_tac R=R' in has_only_Says'D, simp)
       
   292 apply (case_tac R', clarsimp, blast)
       
   293 (* evs2 = ab # list *)
       
   294 apply (frule has_only_Says'D, simp)
       
   295 apply (clarsimp, rule conjI)
       
   296 apply (drule Proto, simp+, blast dest: safe_insert)
       
   297 (* apm s X:guard n Ks *)
       
   298 apply (frule Proto, simp+)
       
   299 apply (erule preservD', simp+)
       
   300 apply (blast dest: safe_insert)
       
   301 apply (blast dest: safe_insert)
       
   302 by (blast, simp, simp, blast)
       
   303 
       
   304 subsection{*useful properties for guardedness*}
       
   305 
       
   306 lemma newn_neq_used: "[| Nonce n:used evs; ok evs R s; k:newn R |]
       
   307 ==> n ~= nonce s k"
       
   308 by (auto simp: ok_def)
       
   309 
       
   310 lemma ok_Guard: "[| ok evs R s; Guard n Ks (spies evs); x:fst R; is_Says x |]
       
   311 ==> apm s (msg x):parts (spies evs) & apm s (msg x):guard n Ks"
       
   312 apply (unfold ok_def is_Says_def, clarify)
       
   313 apply (drule_tac x="Says A B X" in spec, simp)
       
   314 by (drule Says_imp_spies, auto intro: parts_parts)
       
   315 
       
   316 lemma ok_parts_not_new: "[| Y:parts (spies evs); Nonce (nonce s n):parts {Y};
       
   317 ok evs R s |] ==> n ~:newn R"
       
   318 by (auto simp: ok_def dest: not_used_not_spied parts_parts)
       
   319 
       
   320 subsection{*unicity*}
       
   321 
       
   322 constdefs uniq :: "proto => secfun => bool"
       
   323 "uniq p secret == ALL evs R R' n n' Ks s s'. R:p --> R':p -->
       
   324 n:newn R --> n':newn R' --> nonce s n = nonce s' n' -->
       
   325 Nonce (nonce s n):parts {apm' s R} --> Nonce (nonce s n):parts {apm' s' R'} -->
       
   326 apm' s R:guard (nonce s n) Ks --> apm' s' R':guard (nonce s n) Ks -->
       
   327 evs:tr p --> Nonce (nonce s n) ~:analz (spies evs) -->
       
   328 secret R n s Ks:parts (spies evs) --> secret R' n' s' Ks:parts (spies evs) -->
       
   329 secret R n s Ks = secret R' n' s' Ks"
       
   330 
       
   331 lemma uniqD: "[| uniq p secret; evs: tr p; R:p; R':p; n:newn R; n':newn R';
       
   332 nonce s n = nonce s' n'; Nonce (nonce s n) ~:analz (spies evs);
       
   333 Nonce (nonce s n):parts {apm' s R}; Nonce (nonce s n):parts {apm' s' R'};
       
   334 secret R n s Ks:parts (spies evs); secret R' n' s' Ks:parts (spies evs);
       
   335 apm' s R:guard (nonce s n) Ks; apm' s' R':guard (nonce s n) Ks |] ==>
       
   336 secret R n s Ks = secret R' n' s' Ks"
       
   337 by (unfold uniq_def, blast)
       
   338 
       
   339 constdefs ord :: "proto => (rule => rule => bool) => bool"
       
   340 "ord p inf == ALL R R'. R:p --> R':p --> ~ inf R R' --> inf R' R"
       
   341 
       
   342 lemma ordD: "[| ord p inf; ~ inf R R'; R:p; R':p |] ==> inf R' R"
       
   343 by (unfold ord_def, blast)
       
   344 
       
   345 constdefs uniq' :: "proto => (rule => rule => bool) => secfun => bool"
       
   346 "uniq' p inf secret == ALL evs R R' n n' Ks s s'. R:p --> R':p -->
       
   347 inf R R' --> n:newn R --> n':newn R' --> nonce s n = nonce s' n' -->
       
   348 Nonce (nonce s n):parts {apm' s R} --> Nonce (nonce s n):parts {apm' s' R'} -->
       
   349 apm' s R:guard (nonce s n) Ks --> apm' s' R':guard (nonce s n) Ks -->
       
   350 evs:tr p --> Nonce (nonce s n) ~:analz (spies evs) -->
       
   351 secret R n s Ks:parts (spies evs) --> secret R' n' s' Ks:parts (spies evs) -->
       
   352 secret R n s Ks = secret R' n' s' Ks"
       
   353 
       
   354 lemma uniq'D: "[| uniq' p inf secret; evs: tr p; inf R R'; R:p; R':p; n:newn R;
       
   355 n':newn R'; nonce s n = nonce s' n'; Nonce (nonce s n) ~:analz (spies evs);
       
   356 Nonce (nonce s n):parts {apm' s R}; Nonce (nonce s n):parts {apm' s' R'};
       
   357 secret R n s Ks:parts (spies evs); secret R' n' s' Ks:parts (spies evs);
       
   358 apm' s R:guard (nonce s n) Ks; apm' s' R':guard (nonce s n) Ks |] ==>
       
   359 secret R n s Ks = secret R' n' s' Ks"
       
   360 by (unfold uniq'_def, blast)
       
   361 
       
   362 lemma uniq'_imp_uniq: "[| uniq' p inf secret; ord p inf |] ==> uniq p secret"
       
   363 apply (unfold uniq_def)
       
   364 apply (rule allI)+
       
   365 apply (case_tac "inf R R'")
       
   366 apply (blast dest: uniq'D)
       
   367 by (auto dest: ordD uniq'D intro: sym)
       
   368 
       
   369 subsection{*Needham-Schroeder-Lowe*}
       
   370 
       
   371 constdefs
       
   372 a :: agent "a == Friend 0"
       
   373 b :: agent "b == Friend 1"
       
   374 a' :: agent "a' == Friend 2"
       
   375 b' :: agent "b' == Friend 3"
       
   376 Na :: nat "Na == 0"
       
   377 Nb :: nat "Nb == 1"
       
   378 
       
   379 consts
       
   380 ns :: proto
       
   381 ns1 :: rule
       
   382 ns2 :: rule
       
   383 ns3 :: rule
       
   384 
       
   385 translations
       
   386 "ns1" == "({}, Says a b (Crypt (pubK b) {|Nonce Na, Agent a|}))"
       
   387 
       
   388 "ns2" == "({Says a' b (Crypt (pubK b) {|Nonce Na, Agent a|})},
       
   389 Says b a (Crypt (pubK a) {|Nonce Na, Nonce Nb, Agent b|}))"
       
   390 
       
   391 "ns3" == "({Says a b (Crypt (pubK b) {|Nonce Na, Agent a|}),
       
   392 Says b' a (Crypt (pubK a) {|Nonce Na, Nonce Nb, Agent b|})},
       
   393 Says a b (Crypt (pubK b) (Nonce Nb)))"
       
   394 
       
   395 inductive ns intros
       
   396 [iff]: "ns1:ns"
       
   397 [iff]: "ns2:ns"
       
   398 [iff]: "ns3:ns"
       
   399 
       
   400 syntax
       
   401 ns3a :: msg
       
   402 ns3b :: msg
       
   403 
       
   404 translations
       
   405 "ns3a" => "Says a b (Crypt (pubK b) {|Nonce Na, Agent a|})"
       
   406 "ns3b" => "Says b' a (Crypt (pubK a) {|Nonce Na, Nonce Nb, Agent b|})"
       
   407 
       
   408 constdefs keys :: "keyfun"
       
   409 "keys R' s' n evs == {priK' s' a, priK' s' b}"
       
   410 
       
   411 lemma "monoton ns keys"
       
   412 by (simp add: keys_def monoton_def)
       
   413 
       
   414 constdefs secret :: "secfun"
       
   415 "secret R n s Ks ==
       
   416 (if R=ns1 then apm s (Crypt (pubK b) {|Nonce Na, Agent a|})
       
   417 else if R=ns2 then apm s (Crypt (pubK a) {|Nonce Na, Nonce Nb, Agent b|})
       
   418 else Number 0)"
       
   419 
       
   420 constdefs inf :: "rule => rule => bool"
       
   421 "inf R R' == (R=ns1 | (R=ns2 & R'~=ns1) | (R=ns3 & R'=ns3))"
       
   422 
       
   423 lemma inf_is_ord [iff]: "ord ns inf"
       
   424 apply (unfold ord_def inf_def)
       
   425 apply (rule allI)+
       
   426 by (rule impI, erule ns.cases, simp_all)+
       
   427 
       
   428 subsection{*general properties*}
       
   429 
       
   430 lemma ns_has_only_Says' [iff]: "has_only_Says' ns"
       
   431 apply (unfold has_only_Says'_def)
       
   432 apply (rule allI, rule impI)
       
   433 by (erule ns.cases, auto)
       
   434 
       
   435 lemma newn_ns1 [iff]: "newn ns1 = {Na}"
       
   436 by (simp add: newn_def)
       
   437 
       
   438 lemma newn_ns2 [iff]: "newn ns2 = {Nb}"
       
   439 by (auto simp: newn_def Na_def Nb_def)
       
   440 
       
   441 lemma newn_ns3 [iff]: "newn ns3 = {}"
       
   442 by (auto simp: newn_def)
       
   443 
       
   444 lemma ns_wdef [iff]: "wdef ns"
       
   445 by (auto simp: wdef_def elim: ns.cases)
       
   446 
       
   447 subsection{*guardedness for NSL*}
       
   448 
       
   449 lemma "uniq ns secret ==> preserv ns keys n Ks"
       
   450 apply (unfold preserv_def)
       
   451 apply (rule allI)+
       
   452 apply (rule impI, rule impI, rule impI, rule impI, rule impI)
       
   453 apply (erule fresh_ruleD, simp, simp, simp, simp)
       
   454 apply (rule allI)+
       
   455 apply (rule impI, rule impI, rule impI)
       
   456 apply (erule ns.cases)
       
   457 (* fresh with NS1 *)
       
   458 apply (rule impI, rule impI, rule impI, rule impI, rule impI, rule impI)
       
   459 apply (erule ns.cases)
       
   460 (* NS1 *)
       
   461 apply clarsimp
       
   462 apply (frule newn_neq_used, simp, simp)
       
   463 apply (rule No_Nonce, simp)
       
   464 (* NS2 *)
       
   465 apply clarsimp
       
   466 apply (frule newn_neq_used, simp, simp)
       
   467 apply (case_tac "nonce sa Na = nonce s Na")
       
   468 apply (frule Guard_safe, simp)
       
   469 apply (frule Crypt_guard_invKey, simp)
       
   470 apply (frule ok_Guard, simp, simp, simp, clarsimp)
       
   471 apply (frule_tac K="pubK' s b" in Crypt_guard_invKey, simp)
       
   472 apply (frule_tac R=ns1 and R'=ns1 and Ks=Ks and s=sa and s'=s in uniqD, simp+)
       
   473 apply (simp add: secret_def, simp add: secret_def, force, force)
       
   474 apply (simp add: secret_def keys_def, blast)
       
   475 apply (rule No_Nonce, simp)
       
   476 (* NS3 *)
       
   477 apply clarsimp
       
   478 apply (case_tac "nonce sa Na = nonce s Nb")
       
   479 apply (frule Guard_safe, simp)
       
   480 apply (frule Crypt_guard_invKey, simp)
       
   481 apply (frule_tac x=ns3b in ok_Guard, simp, simp, simp, clarsimp)
       
   482 apply (frule_tac K="pubK' s a" in Crypt_guard_invKey, simp)
       
   483 apply (frule_tac R=ns1 and R'=ns2 and Ks=Ks and s=sa and s'=s in uniqD, simp+)
       
   484 apply (simp add: secret_def, simp add: secret_def, force, force)
       
   485 apply (simp add: secret_def, rule No_Nonce, simp)
       
   486 (* fresh with NS2 *)
       
   487 apply (rule impI, rule impI, rule impI, rule impI, rule impI, rule impI)
       
   488 apply (erule ns.cases)
       
   489 (* NS1 *)
       
   490 apply clarsimp
       
   491 apply (frule newn_neq_used, simp, simp)
       
   492 apply (rule No_Nonce, simp)
       
   493 (* NS2 *)
       
   494 apply clarsimp
       
   495 apply (frule newn_neq_used, simp, simp)
       
   496 apply (case_tac "nonce sa Nb = nonce s Na")
       
   497 apply (frule Guard_safe, simp)
       
   498 apply (frule Crypt_guard_invKey, simp)
       
   499 apply (frule ok_Guard, simp, simp, simp, clarsimp)
       
   500 apply (frule_tac K="pubK' s b" in Crypt_guard_invKey, simp)
       
   501 apply (frule_tac R=ns2 and R'=ns1 and Ks=Ks and s=sa and s'=s in uniqD, simp+)
       
   502 apply (simp add: secret_def, simp add: secret_def, force, force)
       
   503 apply (simp add: secret_def, rule No_Nonce, simp)
       
   504 (* NS3 *)
       
   505 apply clarsimp
       
   506 apply (case_tac "nonce sa Nb = nonce s Nb")
       
   507 apply (frule Guard_safe, simp)
       
   508 apply (frule Crypt_guard_invKey, simp)
       
   509 apply (frule_tac x=ns3b in ok_Guard, simp, simp, simp, clarsimp)
       
   510 apply (frule_tac K="pubK' s a" in Crypt_guard_invKey, simp)
       
   511 apply (frule_tac R=ns2 and R'=ns2 and Ks=Ks and s=sa and s'=s in uniqD, simp+)
       
   512 apply (simp add: secret_def, simp add: secret_def, force, force)
       
   513 apply (simp add: secret_def keys_def, blast)
       
   514 apply (rule No_Nonce, simp)
       
   515 (* fresh with NS3 *)
       
   516 by simp
       
   517 
       
   518 subsection{*unicity for NSL*}
       
   519 
       
   520 lemma "uniq' ns inf secret"
       
   521 apply (unfold uniq'_def)
       
   522 apply (rule allI)+
       
   523 apply (rule impI, erule ns.cases)
       
   524 (* R = ns1 *)
       
   525 apply (rule impI, erule ns.cases)
       
   526 (* R' = ns1 *)
       
   527 apply (rule impI, rule impI, rule impI, rule impI)
       
   528 apply (rule impI, rule impI, rule impI, rule impI)
       
   529 apply (rule impI, erule tr.induct)
       
   530 (* Nil *)
       
   531 apply (simp add: secret_def)
       
   532 (* Fake *)
       
   533 apply (clarify, simp add: secret_def)
       
   534 apply (drule notin_analz_insert)
       
   535 apply (drule Crypt_insert_synth, simp, simp, simp)
       
   536 apply (drule Crypt_insert_synth, simp, simp, simp, simp)
       
   537 (* Proto *)
       
   538 apply (erule_tac P="ok evsa Ra sa" in rev_mp)
       
   539 apply (erule ns.cases)
       
   540 (* ns1 *)
       
   541 apply (clarify, simp add: secret_def)
       
   542 apply (erule disjE, erule disjE, clarsimp)
       
   543 apply (drule ok_parts_not_new, simp, simp, simp)
       
   544 apply (clarify, drule ok_parts_not_new, simp, simp, simp)
       
   545 (* ns2 *)
       
   546 apply (simp add: secret_def)
       
   547 (* ns3 *)
       
   548 apply (simp add: secret_def)
       
   549 (* R' = ns2 *)
       
   550 apply (rule impI, rule impI, rule impI, rule impI)
       
   551 apply (rule impI, rule impI, rule impI, rule impI)
       
   552 apply (rule impI, erule tr.induct)
       
   553 (* Nil *)
       
   554 apply (simp add: secret_def)
       
   555 (* Fake *)
       
   556 apply (clarify, simp add: secret_def)
       
   557 apply (drule notin_analz_insert)
       
   558 apply (drule Crypt_insert_synth, simp, simp, simp)
       
   559 apply (drule_tac n="nonce s' Nb" in Crypt_insert_synth, simp, simp, simp, simp)
       
   560 (* Proto *)
       
   561 apply (erule_tac P="ok evsa Ra sa" in rev_mp)
       
   562 apply (erule ns.cases)
       
   563 (* ns1 *)
       
   564 apply (clarify, simp add: secret_def)
       
   565 apply (drule_tac s=sa and n=Na in ok_parts_not_new, simp, simp, simp)
       
   566 (* ns2 *)
       
   567 apply (clarify, simp add: secret_def)
       
   568 apply (drule_tac s=sa and n=Nb in ok_parts_not_new, simp, simp, simp)
       
   569 (* ns3 *)
       
   570 apply (simp add: secret_def)
       
   571 (* R' = ns3 *)
       
   572 apply simp
       
   573 (* R = ns2 *)
       
   574 apply (rule impI, erule ns.cases)
       
   575 (* R' = ns1 *)
       
   576 apply (simp only: inf_def, blast)
       
   577 (* R' = ns2 *)
       
   578 apply (rule impI, rule impI, rule impI, rule impI)
       
   579 apply (rule impI, rule impI, rule impI, rule impI)
       
   580 apply (rule impI, erule tr.induct)
       
   581 (* Nil *)
       
   582 apply (simp add: secret_def)
       
   583 (* Fake *)
       
   584 apply (clarify, simp add: secret_def)
       
   585 apply (drule notin_analz_insert)
       
   586 apply (drule_tac n="nonce s' Nb" in Crypt_insert_synth, simp, simp, simp)
       
   587 apply (drule_tac n="nonce s' Nb" in Crypt_insert_synth, simp, simp, simp, simp)
       
   588 (* Proto *)
       
   589 apply (erule_tac P="ok evsa Ra sa" in rev_mp)
       
   590 apply (erule ns.cases)
       
   591 (* ns1 *)
       
   592 apply (simp add: secret_def)
       
   593 (* ns2 *)
       
   594 apply (clarify, simp add: secret_def)
       
   595 apply (erule disjE, erule disjE, clarsimp, clarsimp)
       
   596 apply (drule_tac s=sa and n=Nb in ok_parts_not_new, simp, simp, simp)
       
   597 apply (erule disjE, clarsimp)
       
   598 apply (drule_tac s=sa and n=Nb in ok_parts_not_new, simp, simp, simp)
       
   599 by (simp_all add: secret_def)
       
   600 
       
   601 end