| Message ID | 20210420114124.9684-19-varad.gautam@suse.com |
|---|---|
| State | New |
| Headers | show |
| Series | Implement RSASSA-PSS signature verification | expand |
On Tue, Apr 20, 2021 at 13:41:23 +0200, Varad Gautam wrote: > keyctl pkey_* operations accept enc and hash parameters at present. > RSASSA-PSS signatures also require passing in the signature salt > length and the mgf hash function. > > Add parameters: > - 'saltlen' to feed in salt length of a PSS signature. > - 'mgfhash' to feed in the hash function used for MGF. > > Signed-off-by: Varad Gautam <varad.gautam@suse.com> > CC: Jarkko Sakkinen <jarkko@kernel.org> > CC: Ben Boeckel <me@benboeckel.net> > --- > v3: Rename slen to saltlen, update Documentation/security/keys/core.rst. > > Documentation/security/keys/core.rst | 14 +++++++++++++- > crypto/asymmetric_keys/asymmetric_type.c | 2 ++ > include/linux/keyctl.h | 2 ++ > security/keys/keyctl_pkey.c | 13 +++++++++++++ > 4 files changed, 30 insertions(+), 1 deletion(-) > > diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst > index b3ed5c581034c..4bd774c56899e 100644 > --- a/Documentation/security/keys/core.rst > +++ b/Documentation/security/keys/core.rst > @@ -1022,6 +1022,15 @@ The keyctl syscall functions are: > which hash function was used, the hash function can be > specified with this, eg. "hash=sha256". > > + ``mgfhash=<algo>`` In case of "RSASSA-PSS" ("enc=pss"), this specifies > + the hash function used with the Mask Generation Function > + to generate a signature, eg. "mgfhash=sha256". Supported > + hashes are: sha1, sha224, sha256, sha384, and sha512. > + > + ``saltlen=<salt_length>`` In case of "RSASSA-PSS" ("enc=pss"), this > + specifies the salt length as a u16, used to generate a ^ This feels like it is missing a comma at the designated location (after `length` if the whitespace gets mangled). > + signature. Eg. "saltlen=32". > + > The ``__spare[]`` space in the parameter block must be set to 0. This is > intended, amongst other things, to allow the passing of passphrases > required to unlock a key. > @@ -1700,6 +1709,8 @@ The structure has a number of fields, some of which are mandatory: > __u32 in2_len; > }; > enum kernel_pkey_operation op : 8; > + __u16 salt_len; > + const char *mgf_hash_algo; > }; > > This includes the key to be used; a string indicating the encoding to use > @@ -1707,7 +1718,8 @@ The structure has a number of fields, some of which are mandatory: > RSASSA-PKCS1-v1.5 or RSAES-PKCS1-v1.5 encoding or "raw" if no encoding); > the name of the hash algorithm used to generate the data for a signature > (if appropriate); the sizes of the input and output (or second input) > - buffers; and the ID of the operation to be performed. > + buffers; the ID of the operation to be performed; salt length to be used > + in case of RSASSA-PSS; and hash algorithm used with MGF for RSASSA-PSS. > > For a given operation ID, the input and output buffers are used as > follows:: Thanks for the docs, they look good to me overall. Other than the comma: Acked-by: Ben Boeckel <mathstuf@gmail.com> --Ben
diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst index b3ed5c581034c..4bd774c56899e 100644 --- a/Documentation/security/keys/core.rst +++ b/Documentation/security/keys/core.rst @@ -1022,6 +1022,15 @@ The keyctl syscall functions are: which hash function was used, the hash function can be specified with this, eg. "hash=sha256". + ``mgfhash=<algo>`` In case of "RSASSA-PSS" ("enc=pss"), this specifies + the hash function used with the Mask Generation Function + to generate a signature, eg. "mgfhash=sha256". Supported + hashes are: sha1, sha224, sha256, sha384, and sha512. + + ``saltlen=<salt_length>`` In case of "RSASSA-PSS" ("enc=pss"), this + specifies the salt length as a u16, used to generate a + signature. Eg. "saltlen=32". + The ``__spare[]`` space in the parameter block must be set to 0. This is intended, amongst other things, to allow the passing of passphrases required to unlock a key. @@ -1700,6 +1709,8 @@ The structure has a number of fields, some of which are mandatory: __u32 in2_len; }; enum kernel_pkey_operation op : 8; + __u16 salt_len; + const char *mgf_hash_algo; }; This includes the key to be used; a string indicating the encoding to use @@ -1707,7 +1718,8 @@ The structure has a number of fields, some of which are mandatory: RSASSA-PKCS1-v1.5 or RSAES-PKCS1-v1.5 encoding or "raw" if no encoding); the name of the hash algorithm used to generate the data for a signature (if appropriate); the sizes of the input and output (or second input) - buffers; and the ID of the operation to be performed. + buffers; the ID of the operation to be performed; salt length to be used + in case of RSASSA-PSS; and hash algorithm used with MGF for RSASSA-PSS. For a given operation ID, the input and output buffers are used as follows:: diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index ad8af3d70ac04..2d3419509ec35 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -571,6 +571,8 @@ static int asymmetric_key_verify_signature(struct kernel_pkey_params *params, .hash_algo = params->hash_algo, .digest = (void *)in, .s = (void *)in2, + .salt_length = params->salt_len, + .mgf_hash_algo = params->mgf_hash_algo, }; return verify_signature(params->key, &sig); diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h index 5b79847207ef2..b0122ac6e11c9 100644 --- a/include/linux/keyctl.h +++ b/include/linux/keyctl.h @@ -37,6 +37,8 @@ struct kernel_pkey_params { __u32 in2_len; /* 2nd input data size (verify) */ }; enum kernel_pkey_operation op : 8; + __u16 salt_len; + const char *mgf_hash_algo; }; #endif /* __LINUX_KEYCTL_H */ diff --git a/security/keys/keyctl_pkey.c b/security/keys/keyctl_pkey.c index 5de0d599a2748..019f112474dcd 100644 --- a/security/keys/keyctl_pkey.c +++ b/security/keys/keyctl_pkey.c @@ -24,11 +24,15 @@ enum { Opt_err, Opt_enc, /* "enc=<encoding>" eg. "enc=oaep" */ Opt_hash, /* "hash=<digest-name>" eg. "hash=sha1" */ + Opt_saltlen, /* "saltlen=<salt-length>" eg. "saltlen=32" */ + Opt_mgfhash, /* "mgfhash=<digest-name>" eg. "mgfhash=sha1" */ }; static const match_table_t param_keys = { { Opt_enc, "enc=%s" }, { Opt_hash, "hash=%s" }, + { Opt_saltlen, "saltlen=%u" }, + { Opt_mgfhash, "mgfhash=%s" }, { Opt_err, NULL } }; @@ -63,6 +67,15 @@ static int keyctl_pkey_params_parse(struct kernel_pkey_params *params) params->hash_algo = q; break; + case Opt_saltlen: + if (kstrtou16(q, 0, ¶ms->salt_len)) + return -EINVAL; + break; + + case Opt_mgfhash: + params->mgf_hash_algo = q; + break; + default: return -EINVAL; }
keyctl pkey_* operations accept enc and hash parameters at present. RSASSA-PSS signatures also require passing in the signature salt length and the mgf hash function. Add parameters: - 'saltlen' to feed in salt length of a PSS signature. - 'mgfhash' to feed in the hash function used for MGF. Signed-off-by: Varad Gautam <varad.gautam@suse.com> CC: Jarkko Sakkinen <jarkko@kernel.org> CC: Ben Boeckel <me@benboeckel.net> --- v3: Rename slen to saltlen, update Documentation/security/keys/core.rst. Documentation/security/keys/core.rst | 14 +++++++++++++- crypto/asymmetric_keys/asymmetric_type.c | 2 ++ include/linux/keyctl.h | 2 ++ security/keys/keyctl_pkey.c | 13 +++++++++++++ 4 files changed, 30 insertions(+), 1 deletion(-)