@startuml
 ' keine farben!!
' !theme mimeograph

skinparam shadowing false

Title Attack Flow and Trust Boundaries: manipulated ISO image AND manipulated checksums/signatures (SLSA1)

header
= Attack Flows and Trust Boundaries
Timestamp: %date("yyyy-MM-dd kk:mm Z") 
endheader

legend right
|= STRIDE |= Abbreviation|
|S| Spoofing |
|T| Tampering |
|R| Repudiation |
|I| Information Disclosure |
|DoS| Denial of Service |
|EoP| Elevation of Privilege |

Relationship Colour
|= Colour |= Attack Phase|
|<#ff0000> Red| Initial Exploit |
|<#800080> Deep Purple| Lateral Movement |
|<#ffa500> Orange| Integrity Violation |
|<#008000> Green| Legitimate Signing |

LightGray box: Trust Boundary
Notes on Relation: STRIDE category
DF: Data Flow
AT: Attack Path
endlegend

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rectangle "Internet" #line:LightGray {
  actor "<color:red>Black Hat</color>" as Attacker #FF0000
} 

rectangle "DMZ" #line:LightGray {
  rectangle "Public Web Server:" as WWW
  	note right of WWW : T, I, DoS, EoP
}

rectangle "Internal Network" #line:LightGray {
  rectangle "CVS RelEng" as BS
  	note right of BS : T, R, EoP 
  	database "Release Repo <color:red>HVT</color>" as Repo
	note right of Repo :   S, T, R, I, DoS, EoP
  actor "Security Officer" #00ff00
}




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BS --> Repo : (DF1) Publish ISO + Checksums
"Security Officer" -[#green,thickness=2]-> Repo : (DF2) Sign Checksums (GnuPG)
Repo --> WWW : (DF3) Deploy Artifacts
WWW --> Attacker : (DF4) Distribute ISO + Checksums + Signature



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Attacker -[#red,dashed]-> WWW : (AT1) Exploit Webserver Vuln
note on link: EoP 

WWW -[#purple,dashed]-> Repo : (AT2) Pivot to Repo
note on link: EoP 

Repo -[#orange,dashed,thickness=2]-> Repo : (AT3) Replace ISO\n&& Checksum\n&& Signature
note on link: Tamper

' Repo -[#orange,dashed]-> Repo : (AT4) Modify Checksums\n
' note on link: Tamper
' 
' Repo -[#orange,dashed]-> Repo : (AT5) Replace GPG Signature\n
' note on link: Tamper




@enduml