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charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/yXMwQrCMAyA4VcZORtoio7iq4iHNo0uo26jURHG3 t06j9/h/1cwqSoG526FKm81nacGOnTAQ5zugpqbwTvfE9ERhRmXkye0RywFjWOJ1bB3lHMIjkN K0OKlyk0/+/hy/dteaRR+/m6wbV99o+HEegAAAA== X-Change-ID: 20261114-ecc-p521-small-scalars-601dd880c8bb To: Lukas Wunner , Ignat Korchagin , Stefan Berger , Herbert Xu , "David S. Miller" , Jarkko Sakkinen Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Erwin Pawliczek , Arun Iyengar X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1794645852; l=918; i=aiyengar1990@gmail.com; s=20261110; h=from:subject:message-id; bh=s/LhpwHvt85EydqWoJFpNYvfgoCBmP/uoS1ROXm5kcc=; b=lJW3yZ+EzBLCAxAaFW+n4QfoqajhwxxjfNDyRbxDH52TVcvIsagGMvsHBVjiTQYeHgusT/Cke cV8blHRizvZB+ftFvqsLdFcQjaPbOz0wD2NXEPBtSjuFNTFsHiZPEMa X-Developer-Key: i=aiyengar1990@gmail.com; a=ed25519; pk=zXpRgUTrhaFe6jLyPqbBy3ccfkj04w0g2690Wv3mg+0= X-Endpoint-Received: by B4 Relay for aiyengar1990@gmail.com/20261110 with auth_id=1480 X-Original-From: Arun Iyengar Reply-To: aiyengar1990@gmail.com Two P-521 fixes for crypto/ecc.c. Patch 1 keeps the random initial Z from commit cd65eaf17841 below 2^521: with 576 bits, every P-521 ecc_make_pub_key() call fails with -EAGAIN. Patch 2 fixes the scalar multiplication for scalars below about 2^259.5. No in-tree caller is affected yet. This series was developed with Claude (Anthropic) as a coding assistant: it wrote the code and the commit messages. I reviewed it and tested it as described in each patch. --- Arun Iyengar (2): crypto: ecc - Keep the random initial Z below 2^521 on P-521 crypto: ecc - Fix P-521 scalar multiplication for small scalars crypto/ecc.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) --- base-commit: 8ba9044ff0bf4a5789216496019fad614eeafd45 change-id: 20261114-ecc-p521-small-scalars-601dd880c8bb Best regards, -- Arun Iyengar