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author | 2018-10-09 17:46:59 +0100 | |
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committer | 2018-10-26 09:30:46 +0100 | |
commit | 00d60fd3b93219ea854220f0fd264b86398cbc53 (patch) | |
tree | 785d49e4c21db068d4aa4e1ec95bd8e095a3bd2e /Documentation | |
parent | KEYS: Provide key type operations for asymmetric key ops [ver #2] (diff) | |
download | linux-00d60fd3b93219ea854220f0fd264b86398cbc53.tar.gz linux-00d60fd3b93219ea854220f0fd264b86398cbc53.tar.bz2 linux-00d60fd3b93219ea854220f0fd264b86398cbc53.zip |
KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]
Provide five keyctl functions that permit userspace to make use of the new
key type ops for accessing and driving asymmetric keys.
(*) Query an asymmetric key.
long keyctl(KEYCTL_PKEY_QUERY,
key_serial_t key, unsigned long reserved,
struct keyctl_pkey_query *info);
Get information about an asymmetric key. The information is returned
in the keyctl_pkey_query struct:
__u32 supported_ops;
A bit mask of flags indicating which ops are supported. This is
constructed from a bitwise-OR of:
KEYCTL_SUPPORTS_{ENCRYPT,DECRYPT,SIGN,VERIFY}
__u32 key_size;
The size in bits of the key.
__u16 max_data_size;
__u16 max_sig_size;
__u16 max_enc_size;
__u16 max_dec_size;
The maximum sizes in bytes of a blob of data to be signed, a signature
blob, a blob to be encrypted and a blob to be decrypted.
reserved must be set to 0. This is intended for future use to hand
over one or more passphrases needed unlock a key.
If successful, 0 is returned. If the key is not an asymmetric key,
EOPNOTSUPP is returned.
(*) Encrypt, decrypt, sign or verify a blob using an asymmetric key.
long keyctl(KEYCTL_PKEY_ENCRYPT,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
void *out);
long keyctl(KEYCTL_PKEY_DECRYPT,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
void *out);
long keyctl(KEYCTL_PKEY_SIGN,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
void *out);
long keyctl(KEYCTL_PKEY_VERIFY,
const struct keyctl_pkey_params *params,
const char *info,
const void *in,
const void *in2);
Use an asymmetric key to perform a public-key cryptographic operation
a blob of data.
The parameter block pointed to by params contains a number of integer
values:
__s32 key_id;
__u32 in_len;
__u32 out_len;
__u32 in2_len;
For a given operation, the in and out buffers are used as follows:
Operation ID in,in_len out,out_len in2,in2_len
======================= =============== =============== ===========
KEYCTL_PKEY_ENCRYPT Raw data Encrypted data -
KEYCTL_PKEY_DECRYPT Encrypted data Raw data -
KEYCTL_PKEY_SIGN Raw data Signature -
KEYCTL_PKEY_VERIFY Raw data - Signature
info is a string of key=value pairs that supply supplementary
information.
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.
If successful, encrypt, decrypt and sign all return the amount of data
written into the output buffer. Verification returns 0 on success.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Tested-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/security/keys/core.rst | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst index c144978479d5..9521c4207f01 100644 --- a/Documentation/security/keys/core.rst +++ b/Documentation/security/keys/core.rst @@ -859,6 +859,7 @@ The keyctl syscall functions are: and either the buffer length or the OtherInfo length exceeds the allowed length. + * Restrict keyring linkage:: long keyctl(KEYCTL_RESTRICT_KEYRING, key_serial_t keyring, @@ -890,6 +891,116 @@ The keyctl syscall functions are: applicable to the asymmetric key type. + * Query an asymmetric key:: + + long keyctl(KEYCTL_PKEY_QUERY, + key_serial_t key_id, unsigned long reserved, + struct keyctl_pkey_query *info); + + Get information about an asymmetric key. The information is returned in + the keyctl_pkey_query struct:: + + __u32 supported_ops; + __u32 key_size; + __u16 max_data_size; + __u16 max_sig_size; + __u16 max_enc_size; + __u16 max_dec_size; + __u32 __spare[10]; + + ``supported_ops`` contains a bit mask of flags indicating which ops are + supported. This is constructed from a bitwise-OR of:: + + KEYCTL_SUPPORTS_{ENCRYPT,DECRYPT,SIGN,VERIFY} + + ``key_size`` indicated the size of the key in bits. + + ``max_*_size`` indicate the maximum sizes in bytes of a blob of data to be + signed, a signature blob, a blob to be encrypted and a blob to be + decrypted. + + ``__spare[]`` must be set to 0. This is intended for future use to hand + over one or more passphrases needed unlock a key. + + If successful, 0 is returned. If the key is not an asymmetric key, + EOPNOTSUPP is returned. + + + * Encrypt, decrypt, sign or verify a blob using an asymmetric key:: + + long keyctl(KEYCTL_PKEY_ENCRYPT, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + void *out); + + long keyctl(KEYCTL_PKEY_DECRYPT, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + void *out); + + long keyctl(KEYCTL_PKEY_SIGN, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + void *out); + + long keyctl(KEYCTL_PKEY_VERIFY, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + const void *in2); + + Use an asymmetric key to perform a public-key cryptographic operation a + blob of data. For encryption and verification, the asymmetric key may + only need the public parts to be available, but for decryption and signing + the private parts are required also. + + The parameter block pointed to by params contains a number of integer + values:: + + __s32 key_id; + __u32 in_len; + __u32 out_len; + __u32 in2_len; + + ``key_id`` is the ID of the asymmetric key to be used. ``in_len`` and + ``in2_len`` indicate the amount of data in the in and in2 buffers and + ``out_len`` indicates the size of the out buffer as appropriate for the + above operations. + + For a given operation, the in and out buffers are used as follows:: + + Operation ID in,in_len out,out_len in2,in2_len + ======================= =============== =============== =============== + KEYCTL_PKEY_ENCRYPT Raw data Encrypted data - + KEYCTL_PKEY_DECRYPT Encrypted data Raw data - + KEYCTL_PKEY_SIGN Raw data Signature - + KEYCTL_PKEY_VERIFY Raw data - Signature + + ``info`` is a string of key=value pairs that supply supplementary + information. These include: + + ``enc=<encoding>`` The encoding of the encrypted/signature blob. This + can be "pkcs1" for RSASSA-PKCS1-v1.5 or + RSAES-PKCS1-v1.5; "pss" for "RSASSA-PSS"; "oaep" for + "RSAES-OAEP". If omitted or is "raw", the raw output + of the encryption function is specified. + + ``hash=<algo>`` If the data buffer contains the output of a hash + function and the encoding includes some indication of + which hash function was used, the hash function can be + specified with this, eg. "hash=sha256". + + 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. + + If successful, encrypt, decrypt and sign all return the amount of data + written into the output buffer. Verification returns 0 on success. + + Kernel Services =============== |