<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/git/next/linux-next.git/lib/mpi, branch akpm</title>
<subtitle>The linux-next integration testing tree</subtitle>
<id>https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/atom?h=akpm</id>
<link rel='self' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/atom?h=akpm'/>
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<updated>2022-06-24T09:12:29+00:00</updated>
<entry>
<title>crypto: rsa - implement Chinese Remainder Theorem for faster private key operations</title>
<updated>2022-06-24T09:12:29+00:00</updated>
<author>
<name>Ignat Korchagin</name>
<email>ignat@cloudflare.com</email>
</author>
<published>2022-06-17T08:42:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=f145d411a67efacc0731fc3f9c7b2d89fb62523a'/>
<id>urn:sha1:f145d411a67efacc0731fc3f9c7b2d89fb62523a</id>
<content type='text'>
Changes from v1:
  * exported mpi_sub and mpi_mul, otherwise the build fails when RSA is a module

The kernel RSA ASN.1 private key parser already supports only private keys with
additional values to be used with the Chinese Remainder Theorem [1], but these
values are currently not used.

This rudimentary CRT implementation speeds up RSA private key operations for the
following Go benchmark up to ~3x.

This implementation also tries to minimise the allocation of additional MPIs,
so existing MPIs are reused as much as possible (hence the variable names are a
bit weird).

The benchmark used:

```
package keyring_test

import (
	"crypto"
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"io"
	"syscall"
	"testing"
	"unsafe"
)

type KeySerial int32
type Keyring int32

const (
	KEY_SPEC_PROCESS_KEYRING Keyring = -2
	KEYCTL_PKEY_SIGN                 = 27
)

var (
	keyTypeAsym = []byte("asymmetric\x00")
	sha256pkcs1 = []byte("enc=pkcs1 hash=sha256\x00")
)

func (keyring Keyring) LoadAsym(desc string, payload []byte) (KeySerial, error) {
	cdesc := []byte(desc + "\x00")
	serial, _, errno := syscall.Syscall6(syscall.SYS_ADD_KEY, uintptr(unsafe.Pointer(&amp;keyTypeAsym[0])), uintptr(unsafe.Pointer(&amp;cdesc[0])), uintptr(unsafe.Pointer(&amp;payload[0])), uintptr(len(payload)), uintptr(keyring), uintptr(0))
	if errno == 0 {
		return KeySerial(serial), nil
	}

	return KeySerial(serial), errno
}

type pkeyParams struct {
	key_id         KeySerial
	in_len         uint32
	out_or_in2_len uint32
	__spare        [7]uint32
}

// the output signature buffer is an input parameter here, because we want to
// avoid Go buffer allocation leaking into our benchmarks
func (key KeySerial) Sign(info, digest, out []byte) error {
	var params pkeyParams
	params.key_id = key
	params.in_len = uint32(len(digest))
	params.out_or_in2_len = uint32(len(out))

	_, _, errno := syscall.Syscall6(syscall.SYS_KEYCTL, KEYCTL_PKEY_SIGN, uintptr(unsafe.Pointer(&amp;params)), uintptr(unsafe.Pointer(&amp;info[0])), uintptr(unsafe.Pointer(&amp;digest[0])), uintptr(unsafe.Pointer(&amp;out[0])), uintptr(0))
	if errno == 0 {
		return nil
	}

	return errno
}

func BenchmarkSign(b *testing.B) {
	priv, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		b.Fatalf("failed to generate private key: %v", err)
	}

	pkcs8, err := x509.MarshalPKCS8PrivateKey(priv)
	if err != nil {
		b.Fatalf("failed to serialize the private key to PKCS8 blob: %v", err)
	}

	serial, err := KEY_SPEC_PROCESS_KEYRING.LoadAsym("test rsa key", pkcs8)
	if err != nil {
		b.Fatalf("failed to load the private key into the keyring: %v", err)
	}

	b.Logf("loaded test rsa key: %v", serial)

	digest := make([]byte, 32)
	_, err = io.ReadFull(rand.Reader, digest)
	if err != nil {
		b.Fatalf("failed to generate a random digest: %v", err)
	}

	sig := make([]byte, 256)
	for n := 0; n &lt; b.N; n++ {
		err = serial.Sign(sha256pkcs1, digest, sig)
		if err != nil {
			b.Fatalf("failed to sign the digest: %v", err)
		}
	}

	err = rsa.VerifyPKCS1v15(&amp;priv.PublicKey, crypto.SHA256, digest, sig)
	if err != nil {
		b.Fatalf("failed to verify the signature: %v", err)
	}
}
```

[1]: https://en.wikipedia.org/wiki/RSA_(cryptosystem)#Using_the_Chinese_remainder_algorithm

Signed-off-by: Ignat Korchagin &lt;ignat@cloudflare.com&gt;
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>lib/mpi: export mpi_rshift</title>
<updated>2022-03-02T22:47:52+00:00</updated>
<author>
<name>Nicolai Stange</name>
<email>nstange@suse.de</email>
</author>
<published>2022-02-21T12:11:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=81771ff2411a4cd1224c4b16e0b4247e71bba0de'/>
<id>urn:sha1:81771ff2411a4cd1224c4b16e0b4247e71bba0de</id>
<content type='text'>
A subsequent patch will make the crypto/dh's dh_is_pubkey_valid() to
calculate a safe-prime groups Q parameter from P: Q = (P - 1) / 2. For
implementing this, mpi_rshift() will be needed. Export it so that it's
accessible from crypto/dh.

Signed-off-by: Nicolai Stange &lt;nstange@suse.de&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>lib/mpi: Add the return value check of kcalloc()</title>
<updated>2022-01-07T03:30:01+00:00</updated>
<author>
<name>Zizhuang Deng</name>
<email>sunsetdzz@gmail.com</email>
</author>
<published>2021-12-30T07:03:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=dd827abe296fe4249b2f8c9b95f72f814ea8348c'/>
<id>urn:sha1:dd827abe296fe4249b2f8c9b95f72f814ea8348c</id>
<content type='text'>
Add the return value check of kcalloc() to avoid potential
NULL ptr dereference.

Fixes: a8ea8bdd9df9 ("lib/mpi: Extend the MPI library")
Signed-off-by: Zizhuang Deng &lt;sunsetdzz@gmail.com&gt;
Reviewed-by: Tianjia Zhang &lt;tianjia.zhang@linux.alibaba.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>lib/mpi: use kcalloc in mpi_resize</title>
<updated>2021-08-12T11:17:00+00:00</updated>
<author>
<name>Hongbo Li</name>
<email>herberthbli@tencent.com</email>
</author>
<published>2021-08-05T08:53:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=b6f756726e4dfe75be1883f6a0202dcecdc801ab'/>
<id>urn:sha1:b6f756726e4dfe75be1883f6a0202dcecdc801ab</id>
<content type='text'>
We should set the additional space to 0 in mpi_resize().
So use kcalloc() instead of kmalloc_array().

In lib/mpi/ec.c:
/****************
 * Resize the array of A to NLIMBS. the additional space is cleared
 * (set to 0) [done by m_realloc()]
 */
int mpi_resize(MPI a, unsigned nlimbs)

Like the comment of kernel's mpi_resize() said, the additional space
need to be set to 0, but when a-&gt;d is not NULL, it does not set.

The kernel's mpi lib is from libgcrypt, the mpi resize in libgcrypt
is _gcry_mpi_resize() which set the additional space to 0.

This bug may cause mpi api which use mpi_resize() get wrong result
under the condition of using the additional space without initiation.
If this condition is not met, the bug would not be triggered.
Currently in kernel, rsa, sm2 and dh use mpi lib, and they works well,
so the bug is not triggered in these cases.

add_points_edwards() use the additional space directly, so it will
get a wrong result.

Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Hongbo Li &lt;herberthbli@tencent.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>lib/mpi: fix spelling mistakes</title>
<updated>2021-07-01T18:06:05+00:00</updated>
<author>
<name>Zhen Lei</name>
<email>thunder.leizhen@huawei.com</email>
</author>
<published>2021-07-01T01:55:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=478485f6c0e5936b62c0c9393a865bfb00f037a5'/>
<id>urn:sha1:478485f6c0e5936b62c0c9393a865bfb00f037a5</id>
<content type='text'>
Fix some spelling mistakes in comments:
flaged ==&gt; flagged
bufer ==&gt; buffer
multipler ==&gt; multiplier
MULTIPLER ==&gt; MULTIPLIER
leaset ==&gt; least
chnage ==&gt; change

Link: https://lkml.kernel.org/r/20210604074401.12198-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Cc: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>lib/mpi: Remove unused scalar_copied</title>
<updated>2020-10-30T06:34:45+00:00</updated>
<author>
<name>Herbert Xu</name>
<email>herbert@gondor.apana.org.au</email>
</author>
<published>2020-10-08T05:58:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=d72286943212fdb6d254d08d4cfccdc70603d0ca'/>
<id>urn:sha1:d72286943212fdb6d254d08d4cfccdc70603d0ca</id>
<content type='text'>
The scalar_copied variable is not as the scalar is never copied
in that block.  This patch removes it.

Fixes: d58bb7e55a8a ("lib/mpi: Introduce ec implementation to...")
Reported-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>lib/mpi/mpi-bit.c: fix spello of "functions"</title>
<updated>2020-10-16T18:11:20+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2020-10-16T03:11:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=8d8472cfdefa0f5c839f5c4a507af5e26ee6f5bf'/>
<id>urn:sha1:8d8472cfdefa0f5c839f5c4a507af5e26ee6f5bf</id>
<content type='text'>
Fix typo/spello of "functions".

Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lkml.kernel.org/r/8df15173-a6df-9426-7cad-a2d279bf1170@infradead.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>lib/mpi: Fix unused variable warnings</title>
<updated>2020-10-02T08:02:13+00:00</updated>
<author>
<name>Herbert Xu</name>
<email>herbert@gondor.apana.org.au</email>
</author>
<published>2020-09-25T08:19:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=ae6ee6ae2b4f4534664561161ef8087e08aff2d9'/>
<id>urn:sha1:ae6ee6ae2b4f4534664561161ef8087e08aff2d9</id>
<content type='text'>
This patch removes a number of unused variables and marks others
as unused in order to silence compiler warnings about them.

Fixes: a8ea8bdd9df9 ("lib/mpi: Extend the MPI library")
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Tested-by: Tianjia Zhang &lt;tianjia.zhang@linux.alibaba.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>lib/mpi: Introduce ec implementation to MPI library</title>
<updated>2020-09-25T07:48:54+00:00</updated>
<author>
<name>Tianjia Zhang</name>
<email>tianjia.zhang@linux.alibaba.com</email>
</author>
<published>2020-09-20T16:20:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=d58bb7e55a8a65894cc02f27c3e2bf9403e7c40f'/>
<id>urn:sha1:d58bb7e55a8a65894cc02f27c3e2bf9403e7c40f</id>
<content type='text'>
The implementation of EC is introduced from libgcrypt as the
basic algorithm of elliptic curve, which can be more perfectly
integrated with MPI implementation.
Some other algorithms will be developed based on mpi ecc, such as SM2.

Signed-off-by: Tianjia Zhang &lt;tianjia.zhang@linux.alibaba.com&gt;
Tested-by: Xufeng Zhang &lt;yunbo.xufeng@linux.alibaba.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>lib/mpi: Extend the MPI library</title>
<updated>2020-09-25T07:48:53+00:00</updated>
<author>
<name>Tianjia Zhang</name>
<email>tianjia.zhang@linux.alibaba.com</email>
</author>
<published>2020-09-20T16:20:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=a8ea8bdd9df92a0e5db5b43900abb7a288b8a53e'/>
<id>urn:sha1:a8ea8bdd9df92a0e5db5b43900abb7a288b8a53e</id>
<content type='text'>
Expand the mpi library based on libgcrypt, and the ECC algorithm of
mpi based on libgcrypt requires these functions.
Some other algorithms will be developed based on mpi ecc, such as SM2.

Signed-off-by: Tianjia Zhang &lt;tianjia.zhang@linux.alibaba.com&gt;
Tested-by: Xufeng Zhang &lt;yunbo.xufeng@linux.alibaba.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
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