From b3a8c8a5ebb5b4c3eb7b104364e63c453cc85f14 Mon Sep 17 00:00:00 2001
From: Denis Kenzior <denkenz@gmail.com>
Date: Tue, 9 Oct 2018 17:47:53 +0100
Subject: [PATCH] crypto: rsa-pkcs1pad: Allow hash to be optional [ver #2]
The original pkcs1pad implementation allowed to pad/unpad raw RSA
output. However, this has been taken out in commit:
commit c0d20d22e0ad ("crypto: rsa-pkcs1pad - Require hash to be present")
This patch restored this ability as it is needed by the asymmetric key
implementation.
Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
---
crypto/rsa-pkcs1pad.c | 59 ++++++++++++++++++++++++++++++-------------
1 file changed, 41 insertions(+), 18 deletions(-)
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 812476e468213..cfc04e15fd975 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -392,7 +392,8 @@ static int pkcs1pad_sign(struct akcipher_request *req)
if (!ctx->key_size)
return -EINVAL;
- digest_size = digest_info->size;
+ if (digest_info)
+ digest_size = digest_info->size;
if (req->src_len + digest_size > ctx->key_size - 11)
return -EOVERFLOW;
@@ -412,8 +413,9 @@ static int pkcs1pad_sign(struct akcipher_request *req)
memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
req_ctx->in_buf[ps_end] = 0x00;
- memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
- digest_info->size);
+ if (digest_info)
+ memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
+ digest_info->size);
pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
ctx->key_size - 1 - req->src_len, req->src);
@@ -475,10 +477,13 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
goto done;
pos++;
- if (crypto_memneq(out_buf + pos, digest_info->data, digest_info->size))
- goto done;
+ if (digest_info) {
+ if (crypto_memneq(out_buf + pos, digest_info->data,
+ digest_info->size))
+ goto done;
- pos += digest_info->size;
+ pos += digest_info->size;
+ }
err = 0;
@@ -608,11 +613,14 @@ static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
hash_name = crypto_attr_alg_name(tb[2]);
if (IS_ERR(hash_name))
- return PTR_ERR(hash_name);
+ hash_name = NULL;
- digest_info = rsa_lookup_asn1(hash_name);
- if (!digest_info)
- return -EINVAL;
+ if (hash_name) {
+ digest_info = rsa_lookup_asn1(hash_name);
+ if (!digest_info)
+ return -EINVAL;
+ } else
+ digest_info = NULL;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (!inst)
@@ -632,14 +640,29 @@ static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
err = -ENAMETOOLONG;
- if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
- "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >=
- CRYPTO_MAX_ALG_NAME ||
- snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
- "pkcs1pad(%s,%s)",
- rsa_alg->base.cra_driver_name, hash_name) >=
- CRYPTO_MAX_ALG_NAME)
- goto out_drop_alg;
+ if (!hash_name) {
+ if (snprintf(inst->alg.base.cra_name,
+ CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
+ rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
+ goto out_drop_alg;
+
+ if (snprintf(inst->alg.base.cra_driver_name,
+ CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
+ rsa_alg->base.cra_driver_name) >=
+ CRYPTO_MAX_ALG_NAME)
+ goto out_drop_alg;
+ } else {
+ if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
+ "pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
+ hash_name) >= CRYPTO_MAX_ALG_NAME)
+ goto out_drop_alg;
+
+ if (snprintf(inst->alg.base.cra_driver_name,
+ CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
+ rsa_alg->base.cra_driver_name,
+ hash_name) >= CRYPTO_MAX_ALG_NAME)
+ goto out_drop_alg;
+ }
inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
--
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