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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, torvalds@linux-foundation.org,
	Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v3 01/14] mpi: Introduce mpi_key_length()
Date: Wed, 11 Sep 2024 14:28:58 +0200	[thread overview]
Message-ID: <20240911122911.1381864-2-roberto.sassu@huaweicloud.com> (raw)
In-Reply-To: <20240911122911.1381864-1-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:[~2024-09-11 12:29 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-11 12:28 [PATCH v3 00/14] KEYS: Add support for PGP keys and signatures Roberto Sassu
2024-09-11 12:28 ` Roberto Sassu [this message]
2024-09-12 13:26   ` [PATCH v3 01/14] mpi: Introduce mpi_key_length() Jarkko Sakkinen
2024-09-11 12:28 ` [PATCH v3 02/14] rsa: add parser of raw format Roberto Sassu
2024-09-12 13:33   ` Jarkko Sakkinen
2024-09-11 12:29 ` [PATCH v3 03/14] PGPLIB: PGP definitions (RFC 9580) Roberto Sassu
2024-09-12 13:54   ` Jarkko Sakkinen
2024-09-11 12:29 ` [PATCH v3 04/14] PGPLIB: Basic packet parser Roberto Sassu
2024-09-12 13:57   ` Jarkko Sakkinen
2024-09-11 12:29 ` [PATCH v3 05/14] PGPLIB: Signature parser Roberto Sassu
2024-09-12 13:58   ` Jarkko Sakkinen
2024-09-11 12:29 ` [PATCH v3 06/14] KEYS: PGP data parser Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 07/14] KEYS: Provide PGP key description autogeneration Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 08/14] KEYS: PGP-based public key signature verification Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 09/14] KEYS: Retry asym key search with partial ID in restrict_link_by_signature() Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 10/14] KEYS: Calculate key digest and get signature of the key Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 11/14] verification: introduce verify_pgp_signature() Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 12/14] PGP: Provide a key type for testing PGP signatures Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 13/14] KEYS: Provide a function to load keys from a PGP keyring blob Roberto Sassu
2024-09-11 12:29 ` [PATCH v3 14/14] KEYS: Introduce load_pgp_public_keyring() Roberto Sassu
2024-09-13  4:45 ` [PATCH v3 00/14] KEYS: Add support for PGP keys and signatures Herbert Xu
2024-09-13  8:30   ` Roberto Sassu
2024-09-13  9:00     ` Herbert Xu
2024-09-15  7:11     ` Linus Torvalds
2024-09-15  8:07       ` Herbert Xu
2024-09-15  8:40         ` Linus Torvalds
2024-09-15  9:15           ` Herbert Xu
2024-09-15  9:31             ` Herbert Xu
2024-09-15 17:52               ` Roberto Sassu
2024-09-17 11:27                 ` Dr. Greg
2024-09-26  9:41           ` Roberto Sassu
2024-09-27  1:25             ` Dr. Greg
2024-10-04 10:42             ` Roberto Sassu
2024-09-15 10:51       ` Roberto Sassu
2024-09-13  9:32   ` David Howells
2024-09-13 10:46     ` Ard Biesheuvel
2024-09-14 11:29   ` Jarkko Sakkinen

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