From de96f83dcb45dcd0d74c71a746b8189e6b289720 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 21 Feb 2024 13:19:15 +0800 Subject: crypto: dh - Make public key test FIPS-only The function dh_is_pubkey_valid was added to for FIPS but it was only partially conditional to fips_enabled. In particular, the first test in the function relies on the last test to work properly, but the last test is only run in FIPS mode. Fix this inconsistency by making the whole function conditional on fips_enabled. Signed-off-by: Herbert Xu --- crypto/dh.c | 57 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 29 insertions(+), 28 deletions(-) (limited to 'crypto/dh.c') diff --git a/crypto/dh.c b/crypto/dh.c index 0fcad279..68d11d66 100644 --- a/crypto/dh.c +++ b/crypto/dh.c @@ -106,6 +106,12 @@ err_clear_ctx: */ static int dh_is_pubkey_valid(struct dh_ctx *ctx, MPI y) { + MPI val, q; + int ret; + + if (!fips_enabled) + return 0; + if (unlikely(!ctx->p)) return -EINVAL; @@ -125,40 +131,35 @@ static int dh_is_pubkey_valid(struct dh_ctx *ctx, MPI y) * * For the safe-prime groups q = (p - 1)/2. */ - if (fips_enabled) { - MPI val, q; - int ret; + val = mpi_alloc(0); + if (!val) + return -ENOMEM; - val = mpi_alloc(0); - if (!val) - return -ENOMEM; + q = mpi_alloc(mpi_get_nlimbs(ctx->p)); + if (!q) { + mpi_free(val); + return -ENOMEM; + } - q = mpi_alloc(mpi_get_nlimbs(ctx->p)); - if (!q) { - mpi_free(val); - return -ENOMEM; - } + /* + * ->p is odd, so no need to explicitly subtract one + * from it before shifting to the right. + */ + mpi_rshift(q, ctx->p, 1); - /* - * ->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_powm(val, y, q, ctx->p); - mpi_free(q); - if (ret) { - mpi_free(val); - return ret; - } + ret = mpi_powm(val, y, q, ctx->p); + mpi_free(q); + if (ret) { + mpi_free(val); + return ret; + } - ret = mpi_cmp_ui(val, 1); + ret = mpi_cmp_ui(val, 1); - mpi_free(val); + mpi_free(val); - if (ret != 0) - return -EINVAL; - } + if (ret != 0) + return -EINVAL; return 0; } -- cgit v1.2.3