feat: add fix-signature subcommand for externally signed bundles#220
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bryan-anthropic wants to merge 1 commit intomainfrom
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feat: add fix-signature subcommand for externally signed bundles#220bryan-anthropic wants to merge 1 commit intomainfrom
bryan-anthropic wants to merge 1 commit intomainfrom
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Enterprise HSM signers (GaraSign, SignServer, Venafi, Azure SignTool) append PKCS#7 signatures after the ZIP EOCD without updating comment_length. Claude Desktop's adm-zip parser rejects these files. PR #204 fixed this for `mcpb sign` but external signers remain broken. This adds `mcpb fix-signature` which applies the same EOCD fix post-hoc, so enterprises can add one step to their signing pipeline. Validated end-to-end with Autodesk's GaraSign-signed Fusion MCPB: - adm-zip, unzip, Python zipfile all accept the fixed bundle - Claude Desktop installs it successfully - Signature bytes (MCPB_SIG_V1 + PKCS#7 + MCPB_SIG_END) remain intact - Exactly 2 bytes changed (EOCD comment_length field) Relates to #204, #21, #194 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
Enterprise HSM signers (GaraSign, SignServer, Venafi, Azure SignTool) append PKCS#7 signatures after the ZIP EOCD without updating
comment_length. Claude Desktop'sadm-zipparser strictly validates this field and rejects signed bundles with:PR #204 fixed this for
mcpb sign, but external signers don't do ZIP surgery — and arguably shouldn't need to. This PR addsmcpb fix-signatureas a post-signing fixup step that any enterprise can add to their pipeline.What it does
mcpb fix-signature <bundle.mcpb>sets the ZIP EOCDcomment_lengthfield to encompass the trailing signature bytes. This makes the file a spec-valid ZIP (signature lives in the ZIP comment field) while preserving the signature intact.findEocdOffset()andextractSignatureBlock()fromsign.ts— no new ZIP parsing codemcpb sign(comment_length already correct)Validation
Tested end-to-end with a GaraSign-signed MCPB:
adm-zip(Claude Desktop)unzip -tzipfileMCPB_SIG_V1+ PKCS#7 +MCPB_SIG_ENDunchangedPrior art
No other signed-ZIP format appends after EOCD without owning the signing pipeline:
.sigzipsidecarThis subcommand bridges the gap until a signer-friendly format lands in Signatures V2.
Usage
Test plan
sign.e2e.test.ts(222 total, all passing)comment_lengthmcpb signadm-zipvalidation of fixed bundleRelates to #204, #21, #194
🤖 Generated with Claude Code