From 5a30771832aab228e0863e414f9182f86797429e Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:47:07 +0100 Subject: [PATCH] KEYS: Provide missing asymmetric key subops for new key type ops [ver #2] Provide the missing asymmetric key subops for new key type ops. This include query, encrypt, decrypt and create signature. Verify signature already exists. Also provided are accessor functions for this: int query_asymmetric_key(const struct key *key, struct kernel_pkey_query *info); int encrypt_blob(struct kernel_pkey_params *params, const void *data, void *enc); int decrypt_blob(struct kernel_pkey_params *params, const void *enc, void *data); int create_signature(struct kernel_pkey_params *params, const void *data, void *enc); The public_key_signature struct gains an encoding field to carry the encoding for verify_signature(). 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 --- Documentation/crypto/asymmetric-keys.txt | 24 ++++-- crypto/asymmetric_keys/asymmetric_keys.h | 3 + crypto/asymmetric_keys/asymmetric_type.c | 43 +++++++++++ crypto/asymmetric_keys/signature.c | 95 ++++++++++++++++++++++++ include/crypto/public_key.h | 13 +++- include/keys/asymmetric-subtype.h | 9 +++ 6 files changed, 180 insertions(+), 7 deletions(-) diff --git a/Documentation/crypto/asymmetric-keys.txt b/Documentation/crypto/asymmetric-keys.txt index 5969bf42562a..deb656ef008b 100644 --- a/Documentation/crypto/asymmetric-keys.txt +++ b/Documentation/crypto/asymmetric-keys.txt @@ -183,6 +183,10 @@ and looks like the following: void (*describe)(const struct key *key, struct seq_file *m); void (*destroy)(void *payload); + int (*query)(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info); + int (*eds_op)(struct kernel_pkey_params *params, + const void *in, void *out); int (*verify_signature)(const struct key *key, const struct public_key_signature *sig); }; @@ -207,12 +211,22 @@ There are a number of operations defined by the subtype: asymmetric key will look after freeing the fingerprint and releasing the reference on the subtype module. - (3) verify_signature(). + (3) query(). - Optional. These are the entry points for the key usage operations. - Currently there is only the one defined. If not set, the caller will be - given -ENOTSUPP. The subtype may do anything it likes to implement an - operation, including offloading to hardware. + Mandatory. This is a function for querying the capabilities of a key. + + (4) eds_op(). + + Optional. This is the entry point for the encryption, decryption and + signature creation operations (which are distinguished by the operation ID + in the parameter struct). The subtype may do anything it likes to + implement an operation, including offloading to hardware. + + (5) verify_signature(). + + Optional. This is the entry point for signature verification. The + subtype may do anything it likes to implement an operation, including + offloading to hardware. ========================== diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h index ca8e9ac34ce6..7be1ccf4fa9f 100644 --- a/crypto/asymmetric_keys/asymmetric_keys.h +++ b/crypto/asymmetric_keys/asymmetric_keys.h @@ -16,3 +16,6 @@ extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id); extern int __asymmetric_key_hex_to_key_id(const char *id, struct asymmetric_key_id *match_id, size_t hexlen); + +extern int asymmetric_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out); diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index 26539e9a8bda..69a0788a7de5 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "asymmetric_keys.h" MODULE_LICENSE("GPL"); @@ -538,6 +539,45 @@ out: return ret; } +int asymmetric_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out) +{ + const struct asymmetric_key_subtype *subtype; + struct key *key = params->key; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (key->type != &key_type_asymmetric) + return -EINVAL; + subtype = asymmetric_key_subtype(key); + if (!subtype || + !key->payload.data[0]) + return -EINVAL; + if (!subtype->eds_op) + return -ENOTSUPP; + + ret = subtype->eds_op(params, in, out); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +static int asymmetric_key_verify_signature(struct kernel_pkey_params *params, + const void *in, const void *in2) +{ + struct public_key_signature sig = { + .s_size = params->in2_len, + .digest_size = params->in_len, + .encoding = params->encoding, + .hash_algo = params->hash_algo, + .digest = (void *)in, + .s = (void *)in2, + }; + + return verify_signature(params->key, &sig); +} + struct key_type key_type_asymmetric = { .name = "asymmetric", .preparse = asymmetric_key_preparse, @@ -548,6 +588,9 @@ struct key_type key_type_asymmetric = { .destroy = asymmetric_key_destroy, .describe = asymmetric_key_describe, .lookup_restriction = asymmetric_lookup_restriction, + .asym_query = query_asymmetric_key, + .asym_eds_op = asymmetric_key_eds_op, + .asym_verify_signature = asymmetric_key_verify_signature, }; EXPORT_SYMBOL_GPL(key_type_asymmetric); diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c index 28198314bc39..ad95a58c6642 100644 --- a/crypto/asymmetric_keys/signature.c +++ b/crypto/asymmetric_keys/signature.c @@ -16,7 +16,9 @@ #include #include #include +#include #include +#include #include "asymmetric_keys.h" /* @@ -36,6 +38,99 @@ void public_key_signature_free(struct public_key_signature *sig) } EXPORT_SYMBOL_GPL(public_key_signature_free); +/** + * query_asymmetric_key - Get information about an aymmetric key. + * @params: Various parameters. + * @info: Where to put the information. + */ +int query_asymmetric_key(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info) +{ + const struct asymmetric_key_subtype *subtype; + struct key *key = params->key; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (key->type != &key_type_asymmetric) + return -EINVAL; + subtype = asymmetric_key_subtype(key); + if (!subtype || + !key->payload.data[0]) + return -EINVAL; + if (!subtype->query) + return -ENOTSUPP; + + ret = subtype->query(params, info); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(query_asymmetric_key); + +/** + * encrypt_blob - Encrypt data using an asymmetric key + * @params: Various parameters + * @data: Data blob to be encrypted, length params->data_len + * @enc: Encrypted data buffer, length params->enc_len + * + * Encrypt the specified data blob using the private key specified by + * params->key. The encrypted data is wrapped in an encoding if + * params->encoding is specified (eg. "pkcs1"). + * + * Returns the length of the data placed in the encrypted data buffer or an + * error. + */ +int encrypt_blob(struct kernel_pkey_params *params, + const void *data, void *enc) +{ + params->op = kernel_pkey_encrypt; + return asymmetric_key_eds_op(params, data, enc); +} +EXPORT_SYMBOL_GPL(encrypt_blob); + +/** + * decrypt_blob - Decrypt data using an asymmetric key + * @params: Various parameters + * @enc: Encrypted data to be decrypted, length params->enc_len + * @data: Decrypted data buffer, length params->data_len + * + * Decrypt the specified data blob using the private key specified by + * params->key. The decrypted data is wrapped in an encoding if + * params->encoding is specified (eg. "pkcs1"). + * + * Returns the length of the data placed in the decrypted data buffer or an + * error. + */ +int decrypt_blob(struct kernel_pkey_params *params, + const void *enc, void *data) +{ + params->op = kernel_pkey_decrypt; + return asymmetric_key_eds_op(params, enc, data); +} +EXPORT_SYMBOL_GPL(decrypt_blob); + +/** + * create_signature - Sign some data using an asymmetric key + * @params: Various parameters + * @data: Data blob to be signed, length params->data_len + * @enc: Signature buffer, length params->enc_len + * + * Sign the specified data blob using the private key specified by params->key. + * The signature is wrapped in an encoding if params->encoding is specified + * (eg. "pkcs1"). If the encoding needs to know the digest type, this can be + * passed through params->hash_algo (eg. "sha1"). + * + * Returns the length of the data placed in the signature buffer or an error. + */ +int create_signature(struct kernel_pkey_params *params, + const void *data, void *enc) +{ + params->op = kernel_pkey_sign; + return asymmetric_key_eds_op(params, data, enc); +} +EXPORT_SYMBOL_GPL(create_signature); + /** * verify_signature - Initiate the use of an asymmetric key to verify a signature * @key: The asymmetric key to verify against diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index e0b681a717ba..3a1047a0195c 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -14,6 +14,8 @@ #ifndef _LINUX_PUBLIC_KEY_H #define _LINUX_PUBLIC_KEY_H +#include + /* * Cryptographic data for the public-key subtype of the asymmetric key type. * @@ -40,6 +42,7 @@ struct public_key_signature { u8 digest_size; /* Number of bytes in digest */ const char *pkey_algo; const char *hash_algo; + const char *encoding; }; extern void public_key_signature_free(struct public_key_signature *sig); @@ -65,8 +68,14 @@ extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring, const union key_payload *payload, struct key *trusted); -extern int verify_signature(const struct key *key, - const struct public_key_signature *sig); +extern int query_asymmetric_key(const struct kernel_pkey_params *, + struct kernel_pkey_query *); + +extern int encrypt_blob(struct kernel_pkey_params *, const void *, void *); +extern int decrypt_blob(struct kernel_pkey_params *, const void *, void *); +extern int create_signature(struct kernel_pkey_params *, const void *, void *); +extern int verify_signature(const struct key *, + const struct public_key_signature *); int public_key_verify_signature(const struct public_key *pkey, const struct public_key_signature *sig); diff --git a/include/keys/asymmetric-subtype.h b/include/keys/asymmetric-subtype.h index e0a9c2368872..9ce2f0fae57e 100644 --- a/include/keys/asymmetric-subtype.h +++ b/include/keys/asymmetric-subtype.h @@ -17,6 +17,8 @@ #include #include +struct kernel_pkey_query; +struct kernel_pkey_params; struct public_key_signature; /* @@ -34,6 +36,13 @@ struct asymmetric_key_subtype { /* Destroy a key of this subtype */ void (*destroy)(void *payload_crypto, void *payload_auth); + int (*query)(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info); + + /* Encrypt/decrypt/sign data */ + int (*eds_op)(struct kernel_pkey_params *params, + const void *in, void *out); + /* Verify the signature on a key of this subtype (optional) */ int (*verify_signature)(const struct key *key, const struct public_key_signature *sig);