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From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: dhowells@redhat.com, dwmw2@infradead.org,
	herbert@gondor.apana.org.au, davem@davemloft.net
Cc: linux-kernel@vger.kernel.org, keyrings@vger.kernel.org,
	linux-crypto@vger.kernel.org, zohar@linux.ibm.com,
	linux-integrity@vger.kernel.org,
	Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v2 01/14] mpi: Introduce mpi_key_length()
Date: Sun, 18 Aug 2024 18:57:43 +0200	[thread overview]
Message-ID: <20240818165756.629203-2-roberto.sassu@huaweicloud.com> (raw)
In-Reply-To: <20240818165756.629203-1-roberto.sassu@huaweicloud.com>

From: Roberto Sassu <roberto.sassu@huawei.com>

Introduce the new function to get the number of bits and bytes from an MPI.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
 include/linux/mpi.h       |  2 ++
 lib/crypto/mpi/mpicoder.c | 33 ++++++++++++++++++++++++++-------
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/include/linux/mpi.h b/include/linux/mpi.h
index eb0d1c1db208..a7dd4c9d8120 100644
--- a/include/linux/mpi.h
+++ b/include/linux/mpi.h
@@ -90,6 +90,8 @@ enum gcry_mpi_format {
 };
 
 MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes);
+int mpi_key_length(const void *xbuffer, unsigned int ret_nread,
+		   unsigned int *nbits_arg, unsigned int *nbytes_arg);
 MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread);
 int mpi_fromstr(MPI val, const char *str);
 MPI mpi_scanval(const char *string);
diff --git a/lib/crypto/mpi/mpicoder.c b/lib/crypto/mpi/mpicoder.c
index 3cb6bd148fa9..92447a1c8bf9 100644
--- a/lib/crypto/mpi/mpicoder.c
+++ b/lib/crypto/mpi/mpicoder.c
@@ -79,22 +79,41 @@ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes)
 }
 EXPORT_SYMBOL_GPL(mpi_read_raw_data);
 
-MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
+int mpi_key_length(const void *xbuffer, unsigned int ret_nread,
+		   unsigned int *nbits_arg, unsigned int *nbytes_arg)
 {
 	const uint8_t *buffer = xbuffer;
-	unsigned int nbits, nbytes;
-	MPI val;
+	unsigned int nbits;
 
-	if (*ret_nread < 2)
-		return ERR_PTR(-EINVAL);
+	if (ret_nread < 2)
+		return -EINVAL;
 	nbits = buffer[0] << 8 | buffer[1];
 
 	if (nbits > MAX_EXTERN_MPI_BITS) {
 		pr_info("MPI: mpi too large (%u bits)\n", nbits);
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 	}
 
-	nbytes = DIV_ROUND_UP(nbits, 8);
+	if (nbits_arg)
+		*nbits_arg = nbits;
+	if (nbytes_arg)
+		*nbytes_arg = DIV_ROUND_UP(nbits, 8);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mpi_key_length);
+
+MPI mpi_read_from_buffer(const void *xbuffer, unsigned int *ret_nread)
+{
+	const uint8_t *buffer = xbuffer;
+	unsigned int nbytes;
+	MPI val;
+	int ret;
+
+	ret = mpi_key_length(xbuffer, *ret_nread, NULL, &nbytes);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
 	if (nbytes + 2 > *ret_nread) {
 		pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n",
 				nbytes, *ret_nread);
-- 
2.34.1


  reply	other threads:[~2024-08-18 16:59 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-18 16:57 [PATCH v2 00/14] KEYS: Add support for PGP keys and signatures Roberto Sassu
2024-08-18 16:57 ` Roberto Sassu [this message]
2024-08-19 17:55   ` [PATCH v2 01/14] mpi: Introduce mpi_key_length() Jarkko Sakkinen
2024-08-18 16:57 ` [PATCH v2 02/14] rsa: add parser of raw format Roberto Sassu
2024-08-19 17:56   ` Jarkko Sakkinen
2024-08-18 16:57 ` [PATCH v2 03/14] PGPLIB: PGP definitions (RFC 4880) Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 04/14] PGPLIB: Basic packet parser Roberto Sassu
2024-08-19 14:34   ` Jeff Johnson
2024-08-19 15:06     ` Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 05/14] PGPLIB: Signature parser Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 06/14] KEYS: PGP data parser Roberto Sassu
2024-08-19 14:36   ` Jeff Johnson
2024-08-19 14:38     ` Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 07/14] KEYS: Provide PGP key description autogeneration Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 08/14] KEYS: PGP-based public key signature verification Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 09/14] KEYS: Retry asym key search with partial ID in restrict_link_by_signature() Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 10/14] KEYS: Calculate key digest and get signature of the key Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 11/14] verification: introduce verify_pgp_signature() Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 12/14] PGP: Provide a key type for testing PGP signatures Roberto Sassu
2024-08-19 14:37   ` Jeff Johnson
2024-08-18 16:57 ` [PATCH v2 13/14] KEYS: Provide a function to load keys from a PGP keyring blob Roberto Sassu
2024-08-18 16:57 ` [PATCH v2 14/14] KEYS: Introduce load_pgp_public_keyring() Roberto Sassu
2024-08-19 15:08 ` [PATCH v2 00/14] KEYS: Add support for PGP keys and signatures Jonathan McDowell
2024-08-19 15:15   ` Roberto Sassu
2024-08-20 14:12     ` Jonathan McDowell
2024-08-20 14:14       ` Roberto Sassu
2024-09-10 14:36       ` Roberto Sassu
2024-09-10 14:51         ` Roberto Sassu
2024-09-10 15:16           ` Jonathan McDowell
2024-09-11  9:55             ` Roberto Sassu
2024-08-19 16:30 ` Roberto Sassu
2024-08-19 17:53 ` Jarkko Sakkinen

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