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authorDavid Howells <dhowells@redhat.com>2018-10-09 17:47:23 +0100
committerJames Morris <james.morris@microsoft.com>2018-10-26 09:30:46 +0100
commit82f94f24475c89c6d5cb673e1277b5b4394499c8 (patch)
treec0ff719910507c1428bc1367d5d750f5fb3cff96 /crypto
parent039884907787e55166e84e0b654a5342cc8a04ab (diff)
downloadlinux-stericsson-82f94f24475c89c6d5cb673e1277b5b4394499c8.tar.gz
KEYS: Provide software public key query function [ver #2]
Provide a query function for the software public key implementation. This permits information about such a key to be obtained using query_asymmetric_key() or KEYCTL_PKEY_QUERY. 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 'crypto')
-rw-r--r--crypto/asymmetric_keys/public_key.c99
1 files changed, 82 insertions, 17 deletions
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index e929fe1e4106..761bfab352dc 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -60,6 +60,81 @@ static void public_key_destroy(void *payload0, void *payload3)
}
/*
+ * Determine the crypto algorithm name.
+ */
+static
+int software_key_determine_akcipher(const char *encoding,
+ const char *hash_algo,
+ const struct public_key *pkey,
+ char alg_name[CRYPTO_MAX_ALG_NAME])
+{
+ int n;
+
+ if (strcmp(encoding, "pkcs1") == 0) {
+ /* The data wangled by the RSA algorithm is typically padded
+ * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447
+ * sec 8.2].
+ */
+ if (!hash_algo)
+ n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME,
+ "pkcs1pad(%s)",
+ pkey->pkey_algo);
+ else
+ n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME,
+ "pkcs1pad(%s,%s)",
+ pkey->pkey_algo, hash_algo);
+ return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0;
+ }
+
+ if (strcmp(encoding, "raw") == 0) {
+ strcpy(alg_name, pkey->pkey_algo);
+ return 0;
+ }
+
+ return -ENOPKG;
+}
+
+/*
+ * Query information about a key.
+ */
+static int software_key_query(const struct kernel_pkey_params *params,
+ struct kernel_pkey_query *info)
+{
+ struct crypto_akcipher *tfm;
+ struct public_key *pkey = params->key->payload.data[asym_crypto];
+ char alg_name[CRYPTO_MAX_ALG_NAME];
+ int ret, len;
+
+ ret = software_key_determine_akcipher(params->encoding,
+ params->hash_algo,
+ pkey, alg_name);
+ if (ret < 0)
+ return ret;
+
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen);
+ if (ret < 0)
+ goto error_free_tfm;
+
+ len = crypto_akcipher_maxsize(tfm);
+ info->key_size = len * 8;
+ info->max_data_size = len;
+ info->max_sig_size = len;
+ info->max_enc_size = len;
+ info->max_dec_size = len;
+ info->supported_ops = KEYCTL_SUPPORTS_VERIFY;
+ ret = 0;
+
+error_free_tfm:
+ crypto_free_akcipher(tfm);
+ pr_devel("<==%s() = %d\n", __func__, ret);
+ return ret;
+}
+
+/*
* Verify a signature using a public key.
*/
int public_key_verify_signature(const struct public_key *pkey,
@@ -69,8 +144,7 @@ int public_key_verify_signature(const struct public_key *pkey,
struct crypto_akcipher *tfm;
struct akcipher_request *req;
struct scatterlist sig_sg, digest_sg;
- const char *alg_name;
- char alg_name_buf[CRYPTO_MAX_ALG_NAME];
+ char alg_name[CRYPTO_MAX_ALG_NAME];
void *output;
unsigned int outlen;
int ret;
@@ -81,21 +155,11 @@ int public_key_verify_signature(const struct public_key *pkey,
BUG_ON(!sig);
BUG_ON(!sig->s);
- if (!sig->digest)
- return -ENOPKG;
-
- alg_name = sig->pkey_algo;
- if (strcmp(sig->pkey_algo, "rsa") == 0) {
- /* The data wangled by the RSA algorithm is typically padded
- * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447
- * sec 8.2].
- */
- if (snprintf(alg_name_buf, CRYPTO_MAX_ALG_NAME,
- "pkcs1pad(rsa,%s)", sig->hash_algo
- ) >= CRYPTO_MAX_ALG_NAME)
- return -EINVAL;
- alg_name = alg_name_buf;
- }
+ ret = software_key_determine_akcipher(sig->encoding,
+ sig->hash_algo,
+ pkey, alg_name);
+ if (ret < 0)
+ return ret;
tfm = crypto_alloc_akcipher(alg_name, 0, 0);
if (IS_ERR(tfm))
@@ -167,6 +231,7 @@ struct asymmetric_key_subtype public_key_subtype = {
.name_len = sizeof("public_key") - 1,
.describe = public_key_describe,
.destroy = public_key_destroy,
+ .query = software_key_query,
.verify_signature = public_key_verify_signature_2,
};
EXPORT_SYMBOL_GPL(public_key_subtype);