crypto: rsa - only require output buffers as big as needed. (457e6f73) · Commits · 戴 / test

rhe RSA operations explicitly left-align the integers being written skipping any leading zero bytes, but still require the output buffers to include just enough space for the integer + the leading zero bytes. Since the size of integer + the leading zero bytes (i.e. the key modulus size) can now be obtained more easily through crypto_akcipher_maxsize change the operations to only require as big a buffer as actually needed if the caller has that information. The semantics for request->dst_len don't change. Signed-off-by:

Andrew Zaborowski <andrew.zaborowski@intel.com> Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au>

crypto/rsa.c

+0 −24

Original line number	Diff line number	Diff line
		@@ -91,12 +91,6 @@ static int rsa_enc(struct akcipher_request *req)
		goto err_free_c;
		}

		if (req->dst_len < mpi_get_size(pkey->n)) {
		req->dst_len = mpi_get_size(pkey->n);
		ret = -EOVERFLOW;
		goto err_free_c;
		}

		ret = -ENOMEM;
		m = mpi_read_raw_from_sgl(req->src, req->src_len);
		if (!m)
		@@ -136,12 +130,6 @@ static int rsa_dec(struct akcipher_request *req)
		goto err_free_m;
		}

		if (req->dst_len < mpi_get_size(pkey->n)) {
		req->dst_len = mpi_get_size(pkey->n);
		ret = -EOVERFLOW;
		goto err_free_m;
		}

		ret = -ENOMEM;
		c = mpi_read_raw_from_sgl(req->src, req->src_len);
		if (!c)
		@@ -180,12 +168,6 @@ static int rsa_sign(struct akcipher_request *req)
		goto err_free_s;
		}

		if (req->dst_len < mpi_get_size(pkey->n)) {
		req->dst_len = mpi_get_size(pkey->n);
		ret = -EOVERFLOW;
		goto err_free_s;
		}

		ret = -ENOMEM;
		m = mpi_read_raw_from_sgl(req->src, req->src_len);
		if (!m)
		@@ -225,12 +207,6 @@ static int rsa_verify(struct akcipher_request *req)
		goto err_free_m;
		}

		if (req->dst_len < mpi_get_size(pkey->n)) {
		req->dst_len = mpi_get_size(pkey->n);
		ret = -EOVERFLOW;
		goto err_free_m;
		}

		ret = -ENOMEM;
		s = mpi_read_raw_from_sgl(req->src, req->src_len);
		if (!s) {

Admin message