CFE-3294: propagate the secret tag through variable expansion - #6327
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nickanderson wants to merge 4 commits into
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CFE-3294: propagate the secret tag through variable expansion#6327nickanderson wants to merge 4 commits into
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EvalContextVariableGet() always returned the plaintext value, so a caller had no way to ask for a secret-tagged variable to be redacted. Adds a get_secret parameter and *Plaintext wrappers, and moves every existing caller onto the plaintext form. No behaviour change: every call site asks for plaintext, exactly as before. Ticket: CFE-3293 Changelog: None
EvalContextVariableGet() kept the variable's declared type while returning the redacted scalar sentinel, so an indexed read of a secret-tagged container -- mydata[key] -- took the container branch and handed that string to RvalContainerValue(), which aborts with a ProgrammingError. Deriving the type from the value actually being returned fixes it and removes the separate type_out special case. Not reachable yet: no caller passes get_secret=false until the CFE-3294 work. test_secret_container_redacts_indexed_read aborts (SIGABRT) without this and passes with it, and asserts the plaintext reads still work so redaction cannot be faked by breaking container reads. Ticket: CFE-3293 Changelog: None
VARIABLE_TAG_SECRET was a private #define in variable.c, so no code outside that file could ask whether a variable is secret -- which is what every caller that copies a value into a new variable has to do before it can propagate the tag. Moves the constant to variable.h and adds EvalContextVariableIsTaggedSecret() next to EvalContextVariableTags(). Answering via a tag set means allocating one to test a single membership, so this goes straight through VariableResolve(). No behaviour change on its own; the propagation commits that follow use it. Ticket: CFE-3294 Changelog: None
A variable whose value references a secret-tagged variable now inherits the tag, so "laundered" string => "$(password)" is no longer an ordinary variable holding plaintext that every reporting and logging path can read. Reads the value from pp->org_pp rather than the constraint the verify function is given: promises are fully expanded before verification, so by then the "$(password)" reference this keys on has already become its value. Runs on every pass, because a copy written untagged in an earlier pass stays readable for the rest of that pass. Adds FindSecretVariableReferences() in vars.c. Its traversal deliberately mirrors ExpandScalar()'s rather than factoring out a shared iterator -- restructuring a function that central does not belong in a leak fix, but the duplication is real and worth revisiting separately. Only scalar values are inspected, so a list or container assembled out of secrets does not inherit the tag yet. Ticket: CFE-3294 Changelog: Title
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A variable built out of a secret-tagged variable did not inherit the tag, so
left
launderedan ordinary variable holding the plaintext. It now inherits thetag, which is what the two existing redaction points on master key off —
GenericAgentShowVariablesFormatted()andVarRefValueToJson().The value is read from
pp->org_pprather than the constraint the verify functionis handed, because promises are fully expanded before verification — by then
$(password)has already becomehunter2, which is why the taint warning added inCFE-3293 never fired.
Only scalar values are inspected, so a list or container assembled out of secrets
does not inherit the tag yet.
Stacked on #6326.