eMudhra blames buggy script for weak issuing CA keys
Original title: Disgraced former CA eMudhra blames buggy script for hopelessly weak certificates
A 30 April 2025 ceremony truncated eight ECDSA P-384 keys so private scalars were recoverable from public keys.
Former certification authority eMudhra told Bugzilla a custom Python script truncated private keys during a 30 April 2025 ceremony. Sixteen subordinate CA key pairs in its B and C series were generated on Utimaco HSMs, then wrap/unwrapped for transfer to Crypto4A modules because supply constraints blocked the HSMs it wanted for US certificates. The company says it did not test the keys. A Mozilla reviewer found them weak; browsers stopped trusting eMudhra, and the Indian firm left the SSL/TLS CA business.
Unconfirmed: eMudhra’s account is its own Bugzilla post; The Register infers the truncation left single-byte keys such as four.
- The script was meant to produce eight 48-byte ECDSA P-384 private keys.
- Import code truncated unwrapped private values below the expected range.
- eMudhra says the script ran only on an isolated ceremony host, not in emCA.
- Policy changes required new certificates by the end of May.
- Wind-down includes PKI improvements from an independent review.
Impact: Fraudulent certificates could impersonate servers and expose or alter traffic.
| Product | Affected |
|---|---|
| eMudhra B and C series subordinate CA certificates | B and C series |
- 1.Reject certificates issued by eMudhra, as browser makers already do.
From the original article
2 min read at theregister.comCouldn’t get the hardware it needed to generate certs, so tried to code a workaround
By Simon Sharwood · theregister.com
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