From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Mon, 26 Jun 2023 10:33:44 +0000 (+0800)
Subject: crypto: sig - Fix verify call
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=891ebfdfa3d08bf55ebec523c99bb68ac9c34cf7;p=linux.git

crypto: sig - Fix verify call

The dst SG list needs to be set to NULL for verify calls.  Do
this as otherwise the underlying algorithm may fail.

Furthermore the digest needs to be copied just like the source.

Fixes: 6cb8815f41a9 ("crypto: sig - Add interface for sign/verify")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

diff --git a/crypto/akcipher.c b/crypto/akcipher.c
index 8ffd31c44cf6c..e9b6ddcdf1244 100644
--- a/crypto/akcipher.c
+++ b/crypto/akcipher.c
@@ -192,12 +192,17 @@ EXPORT_SYMBOL_GPL(akcipher_register_instance);
 int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data)
 {
 	unsigned int reqsize = crypto_akcipher_reqsize(data->tfm);
-	unsigned int mlen = max(data->slen, data->dlen);
 	struct akcipher_request *req;
 	struct scatterlist *sg;
+	unsigned int mlen;
 	unsigned int len;
 	u8 *buf;
 
+	if (data->dst)
+		mlen = max(data->slen, data->dlen);
+	else
+		mlen = data->slen + data->dlen;
+
 	len = sizeof(*req) + reqsize + mlen;
 	if (len < mlen)
 		return -EOVERFLOW;
@@ -213,9 +218,10 @@ int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data)
 	data->buf = buf;
 	memcpy(buf, data->src, data->slen);
 
-	sg = data->sg;
+	sg = &data->sg;
 	sg_init_one(sg, buf, mlen);
-	akcipher_request_set_crypt(req, sg, sg, data->slen, data->dlen);
+	akcipher_request_set_crypt(req, sg, data->dst ? sg : NULL,
+				   data->slen, data->dlen);
 
 	crypto_init_wait(&data->cwait);
 	akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
diff --git a/crypto/internal.h b/crypto/internal.h
index e3cf5a658d51c..63e59240d5fbf 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -44,7 +44,7 @@ struct crypto_akcipher_sync_data {
 
 	struct akcipher_request *req;
 	struct crypto_wait cwait;
-	struct scatterlist sg[2];
+	struct scatterlist sg;
 	u8 *buf;
 };
 
diff --git a/crypto/sig.c b/crypto/sig.c
index d812555c88af7..b48c18ec65cd4 100644
--- a/crypto/sig.c
+++ b/crypto/sig.c
@@ -128,9 +128,7 @@ int crypto_sig_verify(struct crypto_sig *tfm,
 	if (err)
 		return err;
 
-	sg_init_table(data.sg, 2);
-	sg_set_buf(&data.sg[0], src, slen);
-	sg_set_buf(&data.sg[1], digest, dlen);
+	memcpy(data.buf + slen, digest, dlen);
 
 	return crypto_akcipher_sync_post(&data,
 					 crypto_akcipher_verify(data.req));