[RFC PATCH v2 3/4] crypto: dh - allow user to provide NULL privkey
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STALE3420d
From: Tudor Ambarus <hidden>
Date: 2017-05-17 15:27:35
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
Revision v2 of 2 in this series.
Revisions (2)
- rfc [diff vs current]
- v2 current
If the user provides a NULL private key, the kernel will generate it and further use it for dh. Signed-off-by: Tudor Ambarus <redacted> --- crypto/dh.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/crypto/dh.c b/crypto/dh.c
index 87e3542..7b4ac5b 100644
--- a/crypto/dh.c
+++ b/crypto/dh.c@@ -83,7 +83,9 @@ static int dh_set_secret(struct crypto_kpp *tfm, const void *buf, unsigned int len) { struct dh_ctx *ctx = dh_get_ctx(tfm); + u8 *rndbuf = NULL; struct dh params; + int maxsize; if (crypto_dh_decode_key(buf, len, ¶ms) < 0) return -EINVAL;
@@ -91,7 +93,26 @@ static int dh_set_secret(struct crypto_kpp *tfm, const void *buf, if (dh_set_params(ctx, ¶ms) < 0) return -EINVAL; + if (!params.key || !params.key_size) { + maxsize = crypto_kpp_maxsize(tfm); + if (maxsize < 0) { + dh_clear_params(ctx); + return maxsize; + } + + rndbuf = kmalloc(maxsize, GFP_KERNEL); + if (!rndbuf) { + dh_clear_params(ctx); + return -ENOMEM; + } + + get_random_bytes(rndbuf, maxsize); + params.key = rndbuf; + params.key_size = maxsize; + } + ctx->xa = mpi_read_raw_data(params.key, params.key_size); + kzfree(rndbuf); if (!ctx->xa) { dh_clear_params(ctx); return -EINVAL;
--
2.7.4