From 00d60fd3b93219ea854220f0fd264b86398cbc53 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:46:59 +0100 Subject: 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 Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- include/uapi/linux/keyctl.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/keyctl.h b/include/uapi/linux/keyctl.h index 1d1e9f2877af..f45ee0f69c0c 100644 --- a/include/uapi/linux/keyctl.h +++ b/include/uapi/linux/keyctl.h @@ -61,6 +61,11 @@ #define KEYCTL_INVALIDATE 21 /* invalidate a key */ #define KEYCTL_GET_PERSISTENT 22 /* get a user's persistent keyring */ #define KEYCTL_DH_COMPUTE 23 /* Compute Diffie-Hellman values */ +#define KEYCTL_PKEY_QUERY 24 /* Query public key parameters */ +#define KEYCTL_PKEY_ENCRYPT 25 /* Encrypt a blob using a public key */ +#define KEYCTL_PKEY_DECRYPT 26 /* Decrypt a blob using a public key */ +#define KEYCTL_PKEY_SIGN 27 /* Create a public key signature */ +#define KEYCTL_PKEY_VERIFY 28 /* Verify a public key signature */ #define KEYCTL_RESTRICT_KEYRING 29 /* Restrict keys allowed to link to a keyring */ /* keyctl structures */ @@ -87,4 +92,24 @@ struct keyctl_kdf_params { #define KEYCTL_SUPPORTS_SIGN 0x04 #define KEYCTL_SUPPORTS_VERIFY 0x08 +struct keyctl_pkey_query { + __u32 supported_ops; /* Which ops are supported */ + __u32 key_size; /* Size of the key in bits */ + __u16 max_data_size; /* Maximum size of raw data to sign in bytes */ + __u16 max_sig_size; /* Maximum size of signature in bytes */ + __u16 max_enc_size; /* Maximum size of encrypted blob in bytes */ + __u16 max_dec_size; /* Maximum size of decrypted blob in bytes */ + __u32 __spare[10]; +}; + +struct keyctl_pkey_params { + __s32 key_id; /* Serial no. of public key to use */ + __u32 in_len; /* Input data size */ + union { + __u32 out_len; /* Output buffer size (encrypt/decrypt/sign) */ + __u32 in2_len; /* 2nd input data size (verify) */ + }; + __u32 __spare[7]; +}; + #endif /* _LINUX_KEYCTL_H */ -- cgit v1.2.3