A sig_alg backend has just been introduced with the intent of moving all
asymmetric sign/verify algorithms to it one by one.
Migrate the sign/verify operations from rsa-pkcs1pad.c to a separate
rsassa-pkcs1.c which uses the new backend.
Consequently there are now two templates which build on the "rsa"
akcipher_alg:
* The existing "pkcs1pad" template, which is instantiated as an
akcipher_instance and retains the encrypt/decrypt operations of
RSAES-PKCS1-v1_5 (RFC 8017 sec 7.2).
* The new "pkcs1" template, which is instantiated as a sig_instance
and contains the sign/verify operations of RSASSA-PKCS1-v1_5
(RFC 8017 sec 8.2).
In a separate step, rsa-pkcs1pad.c could optionally be renamed to
rsaes-pkcs1.c for clarity. Additional "oaep" and "pss" templates
could be added for RSAES-OAEP and RSASSA-PSS.
Note that it's currently allowed to allocate a "pkcs1pad(rsa)" transform
without specifying a hash algorithm. That makes sense if the transform
is only used for encrypt/decrypt and continues to be supported. But for
sign/verify, such transforms previously did not insert the Full Hash
Prefix into the padding. The resulting message encoding was incompliant
with EMSA-PKCS1-v1_5 (RFC 8017 sec 9.2) and therefore nonsensical.
From here on in, it is no longer allowed to allocate a transform without
specifying a hash algorithm if the transform is used for sign/verify
operations. This simplifies the code because the insertion of the Full
Hash Prefix is no longer optional, so various "if (digest_info)" clauses
can be removed.
There has been a previous attempt to forbid transform allocation without
specifying a hash algorithm, namely by commit c0d20d22e0 ("crypto:
rsa-pkcs1pad - Require hash to be present"). It had to be rolled back
with commit b3a8c8a5eb ("crypto: rsa-pkcs1pad: Allow hash to be
optional [ver #2]"), presumably because it broke allocation of a
transform which was solely used for encrypt/decrypt, not sign/verify.
Avoid such breakage by allowing transform allocation for encrypt/decrypt
with and without specifying a hash algorithm (and simply ignoring the
hash algorithm in the former case).
So again, specifying a hash algorithm is now mandatory for sign/verify,
but optional and ignored for encrypt/decrypt.
The new sig_alg API uses kernel buffers instead of sglists, which
avoids the overhead of copying signature and digest from sglists back
into kernel buffers. rsassa-pkcs1.c is thus simplified quite a bit.
sig_alg is always synchronous, whereas the underlying "rsa" akcipher_alg
may be asynchronous. So await the result of the akcipher_alg, similar
to crypto_akcipher_sync_{en,de}crypt().
As part of the migration, rename "rsa_digest_info" to "hash_prefix" to
adhere to the spec language in RFC 9580. Otherwise keep the code
unmodified wherever possible to ease reviewing and bisecting. Leave
several simplification and hardening opportunities to separate commits.
rsassa-pkcs1.c uses modern __free() syntax for allocation of buffers
which need to be freed by kfree_sensitive(), hence a DEFINE_FREE()
clause for kfree_sensitive() is introduced herein as a byproduct.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixes: 6637e11e4a ("crypto: rsa - allow only odd e and restrict value in FIPS mode")
Fixes: f145d411a6 ("crypto: rsa - implement Chinese Remainder Theorem for faster private key operation")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
SP 800-56Br2, Section 7.1.1 [1] specifies that:
1. If m does not satisfy 1 < m < (n – 1), output an indication that m is
out of range, and exit without further processing.
Similarly, Section 7.1.2 of the same standard specifies that:
1. If the ciphertext c does not satisfy 1 < c < (n – 1), output an
indication that the ciphertext is out of range, and exit without further
processing.
This range is slightly more conservative than RFC3447, as it also
excludes RSA fixed points 0, 1, and n - 1.
[1] https://doi.org/10.6028/NIST.SP.800-56Br2
Signed-off-by: Joachim Vandersmissen <git@jvdsn.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Static checkers insist that the mpi_alloc() allocation can fail so add
a check to prevent a NULL dereference. Small allocations like this
can't actually fail in current kernels, but adding a check is very
simple and makes the static checkers happy.
Fixes: 6637e11e4a ("crypto: rsa - allow only odd e and restrict value in FIPS mode")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
check if rsa public exponent is odd and check its value is between
2^16 < e < 2^256.
FIPS 186-5 DSS (page 35)[1] specify that:
1. The public exponent e shall be selected with the following constraints:
(a) The public verification exponent e shall be selected prior to
generating the primes, p and q, and the private signature exponent
d.
(b) The exponent e shall be an odd positive integer such that:
2^16 < e < 2^256.
[1] https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-5.pdf
Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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(&keyTypeAsym[0])), uintptr(unsafe.Pointer(&cdesc[0])), uintptr(unsafe.Pointer(&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(¶ms)), uintptr(unsafe.Pointer(&info[0])), uintptr(unsafe.Pointer(&digest[0])), uintptr(unsafe.Pointer(&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 < b.N; n++ {
err = serial.Sign(sha256pkcs1, digest, sig)
if err != nil {
b.Fatalf("failed to sign the digest: %v", err)
}
}
err = rsa.VerifyPKCS1v15(&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 <ignat@cloudflare.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
FIPS disallows RSA with keys < 2048 bits. Thus, the kernel should
consider the enforcement of this limit.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public licence as published by
the free software foundation either version 2 of the licence or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 114 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use subsys_initcall for registration of all templates and generic
algorithm implementations, rather than module_init. Then change
cryptomgr to use arch_initcall, to place it before the subsys_initcalls.
This is needed so that when both a generic and optimized implementation
of an algorithm are built into the kernel (not loadable modules), the
generic implementation is registered before the optimized one.
Otherwise, the self-tests for the optimized implementation are unable to
allocate the generic implementation for the new comparison fuzz tests.
Note that on arm, a side effect of this change is that self-tests for
generic implementations may run before the unaligned access handler has
been installed. So, unaligned accesses will crash the kernel. This is
arguably a good thing as it makes it easier to detect that type of bug.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In preparation for new akcipher verify call remove sign/verify callbacks
from RSA backends and make PKCS1 driver call encrypt/decrypt instead.
This also complies with the well-known idea that raw RSA should never be
used for sign/verify. It only should be used with proper padding scheme
such as PKCS1 driver provides.
Cc: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Cc: qat-linux@intel.com
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Horia Geantă <horia.geanta@nxp.com>
Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Acked-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
There is no need to assign an error value to 'ret' prior
to calling mpi_read_raw_from_sgl() because in the case
of error the 'ret' variable will be assigned to the error
code inside the if block.
In the case of non failure, 'ret' will be overwritten
immediately after, so remove the unneeded assignment.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
crypto_akcipher_maxsize() asks for the output buffer size without
caring for errors. It allways assume that will be called after
a valid setkey. Comply with it and return what he wants.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Every implementation of RSA that we have naturally generates
output with leading zeroes. The one and only user of RSA,
pkcs1pad wants to have those leading zeroes in place, in fact
because they are currently absent it has to write those zeroes
itself.
So we shouldn't be stripping leading zeroes in the first place.
In fact this patch makes rsa-generic produce output with fixed
length so that pkcs1pad does not need to do any extra work.
This patch also changes DH to use the new interface.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Return the raw key with no other processing so that the caller
can copy it or MPI parse it, etc.
The scope is to have only one ANS.1 parser for all RSA
implementations.
Update the RSA software implementation so that it does
the MPI conversion on top.
Signed-off-by: Tudor Ambarus <tudor-dan.ambarus@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds PKCS#1 v1.5 standard RSA padding as a separate template.
This way an RSA cipher with padding can be obtained by instantiating
"pkcs1pad(rsa)". The reason for adding this is that RSA is almost
never used without this padding (or OAEP) so it will be needed for
either certificate work in the kernel or the userspace, and I also hear
that it is likely implemented by hardware RSA in which case hardware
implementations of the whole of pkcs1pad(rsa) can be provided.
Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
rhe RSA operations explicitly left-align the integers being written
skipping any leading zero bytes, but still require the output buffers to
include just enough space for the integer + the leading zero bytes.
Since the size of integer + the leading zero bytes (i.e. the key modulus
size) can now be obtained more easily through crypto_akcipher_maxsize
change the operations to only require as big a buffer as actually needed
if the caller has that information. The semantics for request->dst_len
don't change.
Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Setkey function has been split into set_priv_key and set_pub_key.
Akcipher requests takes sgl for src and dst instead of void *.
Users of the API i.e. two existing RSA implementation and
test mgr code have been updated accordingly.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Introduce constrains for RSA keys lengths.
Only key lengths of 512, 1024, 1536, 2048, 3072, and 4096 bits
will be supported.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a new rsa generic SW implementation.
This implements only cryptographic primitives.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Added select on ASN1.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
