diff options
Diffstat (limited to 'src/input-helper.ts')
| -rw-r--r-- | src/input-helper.ts | 40 |
1 files changed, 32 insertions, 8 deletions
diff --git a/src/input-helper.ts b/src/input-helper.ts index 2d20930..f62ddc6 100644 --- a/src/input-helper.ts +++ b/src/input-helper.ts @@ -59,6 +59,23 @@ export async function getInputs(): Promise<IGitSourceSettings> { // Source branch, source version result.ref = core.getInput('ref') + // core.getInput()'s default trim strips a range of Unicode characters such as a + // leading BOM (U+FEFF) or NBSP (U+00A0). Those are valid in a git ref name, so + // a fork branch named "<BOM>" + 40 hex chars would trim down to a bare SHA and + // be silently reclassified as a commit, bypassing the unsafe fork PR checkout + // guard. + // + // The trim below strips only the ASCII whitespace characters which are all forbidden + // in a git branch name. + // \t U+0009 horizontal tab - ASCII control, forbidden in ref names + // \n U+000A line feed - ASCII control, forbidden in ref names + // \v U+000B vertical tab - ASCII control, forbidden in ref names + // \f U+000C form feed - ASCII control, forbidden in ref names + // \r U+000D carriage return - ASCII control, forbidden in ref names + // ' ' U+0020 space - forbidden in ref names + const asciiTrimmedRef = core + .getInput('ref', {trimWhitespace: false}) + .replace(/^[\t\n\v\f\r ]+|[\t\n\v\f\r ]+$/g, '') if (!result.ref) { if (isWorkflowRepository) { result.ref = github.context.ref @@ -72,8 +89,8 @@ export async function getInputs(): Promise<IGitSourceSettings> { } } // SHA? - else if (result.ref.match(/^(?:[0-9a-fA-F]{40}|[0-9a-fA-F]{64})$/)) { - result.commit = result.ref + else if (asciiTrimmedRef.match(/^(?:[0-9a-fA-F]{40}|[0-9a-fA-F]{64})$/)) { + result.commit = asciiTrimmedRef result.ref = '' } core.debug(`ref = '${result.ref}'`) @@ -168,12 +185,19 @@ export async function getInputs(): Promise<IGitSourceSettings> { 'TRUE' core.debug(`allow unsafe PR checkout = ${result.allowUnsafePrCheckout}`) - unsafePrCheckoutHelper.assertSafePrCheckout({ - qualifiedRepository, - ref: result.ref, - commit: result.commit, - allowUnsafePrCheckout: result.allowUnsafePrCheckout - }) + // The default self-checkout (this repository with no explicit ref) always + // resolves to the trusted ref/commit GitHub set for the triggering event, so + // the fork-checkout guard only needs to run when the caller customized the + // repository or ref. + const isDefaultCheckout = isWorkflowRepository && !core.getInput('ref') + if (!isDefaultCheckout) { + unsafePrCheckoutHelper.assertSafePrCheckout({ + qualifiedRepository, + ref: result.ref, + commit: result.commit, + allowUnsafePrCheckout: result.allowUnsafePrCheckout + }) + } return result } |