diff -r febb8e5d2a9d -r 890d736b93a5 src/HOL/Auth/Guard/OtwayRees.thy --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/HOL/Auth/Guard/OtwayRees.thy Wed Aug 21 15:53:30 2002 +0200 @@ -0,0 +1,195 @@ +(****************************************************************************** +date: march 2002 +author: Frederic Blanqui +email: blanqui@lri.fr +webpage: http://www.lri.fr/~blanqui/ + +University of Cambridge, Computer Laboratory +William Gates Building, JJ Thomson Avenue +Cambridge CB3 0FD, United Kingdom +******************************************************************************) + +header{*Otway-Rees Protocol*} + +theory OtwayRees = Guard_Shared: + +subsection{*messages used in the protocol*} + +syntax nil :: "msg" + +translations "nil" == "Number 0" + +syntax or1 :: "agent => agent => nat => event" + +translations "or1 A B NA" +=> "Says A B {|Nonce NA, Agent A, Agent B, + Ciph A {|Nonce NA, Agent A, Agent B|}|}" + +syntax or1' :: "agent => agent => agent => nat => msg => event" + +translations "or1' A' A B NA X" +=> "Says A' B {|Nonce NA, Agent A, Agent B, X|}" + +syntax or2 :: "agent => agent => nat => nat => msg => event" + +translations "or2 A B NA NB X" +=> "Says B Server {|Nonce NA, Agent A, Agent B, X, + Ciph B {|Nonce NA, Nonce NB, Agent A, Agent B|}|}" + +syntax or2' :: "agent => agent => agent => nat => nat => event" + +translations "or2' B' A B NA NB" +=> "Says B' Server {|Nonce NA, Agent A, Agent B, + Ciph A {|Nonce NA, Agent A, Agent B|}, + Ciph B {|Nonce NA, Nonce NB, Agent A, Agent B|}|}" + +syntax or3 :: "agent => agent => nat => nat => key => event" + +translations "or3 A B NA NB K" +=> "Says Server B {|Nonce NA, Ciph A {|Nonce NA, Key K|}, + Ciph B {|Nonce NB, Key K|}|}" + +syntax or3':: "agent => msg => agent => agent => nat => nat => key => event" + +translations "or3' S Y A B NA NB K" +=> "Says S B {|Nonce NA, Y, Ciph B {|Nonce NB, Key K|}|}" + +syntax or4 :: "agent => agent => nat => msg => event" + +translations "or4 A B NA X" => "Says B A {|Nonce NA, X, nil|}" + +syntax or4' :: "agent => agent => nat => msg => event" + +translations "or4' B' A NA K" => +"Says B' A {|Nonce NA, Ciph A {|Nonce NA, Key K|}, nil|}" + +subsection{*definition of the protocol*} + +consts or :: "event list set" + +inductive or +intros + +Nil: "[]:or" + +Fake: "[| evs:or; X:synth (analz (spies evs)) |] ==> Says Spy B X # evs:or" + +OR1: "[| evs1:or; Nonce NA ~:used evs1 |] ==> or1 A B NA # evs1:or" + +OR2: "[| evs2:or; or1' A' A B NA X:set evs2; Nonce NB ~:used evs2 |] +==> or2 A B NA NB X # evs2:or" + +OR3: "[| evs3:or; or2' B' A B NA NB:set evs3; Key K ~:used evs3 |] +==> or3 A B NA NB K # evs3:or" + +OR4: "[| evs4:or; or2 A B NA NB X:set evs4; or3' S Y A B NA NB K:set evs4 |] +==> or4 A B NA X # evs4:or" + +subsection{*declarations for tactics*} + +declare knows_Spy_partsEs [elim] +declare Fake_parts_insert [THEN subsetD, dest] +declare initState.simps [simp del] + +subsection{*general properties of or*} + +lemma or_has_no_Gets: "evs:or ==> ALL A X. Gets A X ~:set evs" +by (erule or.induct, auto) + +lemma or_is_Gets_correct [iff]: "Gets_correct or" +by (auto simp: Gets_correct_def dest: or_has_no_Gets) + +lemma or_is_one_step [iff]: "one_step or" +by (unfold one_step_def, clarify, ind_cases "ev#evs:or", auto) + +lemma or_has_only_Says' [rule_format]: "evs:or ==> +ev:set evs --> (EX A B X. ev=Says A B X)" +by (erule or.induct, auto) + +lemma or_has_only_Says [iff]: "has_only_Says or" +by (auto simp: has_only_Says_def dest: or_has_only_Says') + +subsection{*or is regular*} + +lemma or1'_parts_spies [dest]: "or1' A' A B NA X:set evs +==> X:parts (spies evs)" +by blast + +lemma or2_parts_spies [dest]: "or2 A B NA NB X:set evs +==> X:parts (spies evs)" +by blast + +lemma or3_parts_spies [dest]: "Says S B {|NA, Y, Ciph B {|NB, K|}|}:set evs +==> K:parts (spies evs)" +by blast + +lemma or_is_regular [iff]: "regular or" +apply (simp only: regular_def, clarify) +apply (erule or.induct, simp_all add: initState.simps knows.simps) +by (auto dest: parts_sub) + +subsection{*guardedness of KAB*} + +lemma Guard_KAB [rule_format]: "[| evs:or; A ~:bad; B ~:bad |] ==> +or3 A B NA NB K:set evs --> GuardK K {shrK A,shrK B} (spies evs)" +apply (erule or.induct) +(* Nil *) +apply simp_all +(* Fake *) +apply (clarify, erule in_synth_GuardK, erule GuardK_analz, simp) +(* OR1 *) +apply blast +(* OR2 *) +apply safe +apply (blast dest: Says_imp_spies, blast) +(* OR3 *) +apply blast +apply (drule_tac A=Server in Key_neq, simp+, rule No_Key, simp) +apply (drule_tac A=Server in Key_neq, simp+, rule No_Key, simp) +(* OR4 *) +by (blast dest: Says_imp_spies in_GuardK_kparts) + +subsection{*guardedness of NB*} + +lemma Guard_NB [rule_format]: "[| evs:or; B ~:bad |] ==> +or2 A B NA NB X:set evs --> Guard NB {shrK B} (spies evs)" +apply (erule or.induct) +(* Nil *) +apply simp_all +(* Fake *) +apply safe +apply (erule in_synth_Guard, erule Guard_analz, simp) +(* OR1 *) +apply (drule_tac n=NB in Nonce_neq, simp+, rule No_Nonce, simp) +apply (drule_tac n=NB in Nonce_neq, simp+, rule No_Nonce, simp) +(* OR2 *) +apply blast +apply (drule_tac n=NA in Nonce_neq, simp+, rule No_Nonce, simp) +apply (blast intro!: No_Nonce dest: used_parts) +apply (drule_tac n=NA in Nonce_neq, simp+, rule No_Nonce, simp) +apply (blast intro!: No_Nonce dest: used_parts) +apply (blast dest: Says_imp_spies) +apply (blast dest: Says_imp_spies) +apply (case_tac "Ba=B", clarsimp) +apply (drule_tac n=NB and A=B in Nonce_neq, simp+) +apply (drule Says_imp_spies) +apply (drule_tac n'=NAa in in_Guard_kparts_neq, simp+, rule No_Nonce, simp) +(* OR3 *) +apply (drule Says_imp_spies) +apply (frule_tac n'=NAa in in_Guard_kparts_neq, simp+, rule No_Nonce, simp) +apply (case_tac "Aa=B", clarsimp) +apply (case_tac "NAa=NB", clarsimp) +apply (drule Says_imp_spies) +apply (drule_tac Y="{|Nonce NB, Agent Aa, Agent Ba|}" + and K="shrK Aa" in in_Guard_kparts_Crypt, simp+) +apply (simp add: No_Nonce) +apply (case_tac "Ba=B", clarsimp) +apply (case_tac "NBa=NB", clarify) +apply (drule Says_imp_spies) +apply (drule_tac Y="{|Nonce NAa, Nonce NB, Agent Aa, Agent Ba|}" + and K="shrK Ba" in in_Guard_kparts_Crypt, simp+) +apply (simp add: No_Nonce) +(* OR4 *) +by (blast dest: Says_imp_spies)+ + +end