crypto: rsa - only require output buffers as big as needed.
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>
diff --git a/crypto/rsa.c b/crypto/rsa.c
index 1093e04..58aad69 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -91,12 +91,6 @@
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 @@
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 @@
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 @@
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) {
