fix(publisher): pad ECDSA P-384 signature to fixed width#1457
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fix(publisher): pad ECDSA P-384 signature to fixed width#1457JosephDoUrden wants to merge 1 commit into
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r.Bytes() and s.Bytes() drop leading zero bytes, so the R || S signature was occasionally shorter than 96 bytes and the registry rejected it with "invalid signature size for ECDSA P-384". Left-pad each component to 48 bytes with FillBytes, matching the googlekms signer.
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The in-process ECDSA P-384 signer built the signature with
append(r.Bytes(), s.Bytes()...). big.Int.Bytes() strips leading zero bytes, so whenever r or s had a high zero byte (roughly 1 in 128 signatures) the concatenation came out shorter than 96 bytes and the registry rejected the publish with "invalid signature size for ECDSA P-384". Intermittent and confusing to debug. Fixed by left-padding each component to 48 bytes with FillBytes, same as the googlekms signer already does. Added a test pinning the fixed-width encoding plus a sign/verify round-trip.