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[v2,3/4] crypto: dh - Check mpi_rshift errors

Message ID 1399d770a75f0e8b0097fd9499a01d34960ee3d4.1723270405.git.herbert@gondor.apana.org.au
State Accepted
Commit 560efa7fca4f4f5bd390e54d43cd2cd1831c60cd
Headers show
Series [v2,1/4] Revert "lib/mpi: Extend the MPI library" | expand

Commit Message

Herbert Xu Aug. 10, 2024, 6:20 a.m. UTC 
Now that mpi_rshift can return errors, check them.

Fixes: 35d2bf20683f ("crypto: dh - calculate Q from P for the full public key verification")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
 crypto/dh.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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Patch

diff --git a/crypto/dh.c b/crypto/dh.c
index 68d11d66c0b5..afc0fd847761 100644
--- a/crypto/dh.c
+++ b/crypto/dh.c
@@ -145,9 +145,9 @@  static int dh_is_pubkey_valid(struct dh_ctx *ctx, MPI y)
 	 * ->p is odd, so no need to explicitly subtract one
 	 * from it before shifting to the right.
 	 */
-	mpi_rshift(q, ctx->p, 1);
+	ret = mpi_rshift(q, ctx->p, 1) ?:
+	      mpi_powm(val, y, q, ctx->p);
 
-	ret = mpi_powm(val, y, q, ctx->p);
 	mpi_free(q);
 	if (ret) {
 		mpi_free(val);