[RFC PATCH] X.509: Parse public key parameters from x509 for akcipher
From: Vitaly Chikunov
Date: Sun Dec 09 2018 - 08:55:59 EST
Some public key algorithms (like ECDSA) keep in parameters field
important data such as digest and curve OIDs (possibly more for
different ECDSA variants). Thus, just setting a public key (as
for RSA) is not enough.
Introduce set_params() callback for akcipher which will be used to
pass BER encoded parameters array, with additional argument of
algorithm OID.
This is done with the intent of adding support for EC-RDSA (ISO/IEC
14888-3:2018, RFC 7091, and basically ECDSA variant) public keys (which
will be finally used in IMA subsystem). Thus, also oid_registry.h is
updated.
Rationale:
- For such keys just setting public key without parameters is
meaningless, so it would be possible to add parameters in
crypto_akcipher_set_pub_key (and .set_pub_key) calls. But, this will
needlessly change API for RSA akcipher. Also, additional callback
making it possible to pass parameters after
crypto_akcipher_set_priv_key (and .set_priv_key) in the future.
- Algorithm OID is passed to be validated in .set_params callback,
otherwise, it could have the wrong value.
- Particular algorithm OIDs are checked in x509_note_params, (because
this is called from AlgorithmIdentifier (ASN.1) parser, which is
called multiple times, as it's used multiple times in X.509
certificate), to distinguish a public key call from a signature call.
Signed-off-by: Vitaly Chikunov <vt@xxxxxxxxxxxx>
---
crypto/asymmetric_keys/public_key.c | 16 +++++++++++++++
crypto/asymmetric_keys/x509.asn1 | 2 +-
crypto/asymmetric_keys/x509_cert_parser.c | 27 +++++++++++++++++++++++++
crypto/testmgr.c | 5 +++++
crypto/testmgr.h | 3 +++
include/crypto/akcipher.h | 33 +++++++++++++++++++++++++++++++
include/crypto/public_key.h | 4 ++++
include/linux/oid_registry.h | 6 ++++++
8 files changed, 95 insertions(+), 1 deletion(-)
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index f5d85b47fcc6..3bc090b8adef 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -45,6 +45,7 @@ void public_key_free(struct public_key *key)
{
if (key) {
kfree(key->key);
+ kfree(key->params);
kfree(key);
}
}
@@ -124,6 +125,11 @@ static int software_key_query(const struct kernel_pkey_params *params,
if (ret < 0)
goto error_free_tfm;
+ ret = crypto_akcipher_set_params(tfm, pkey->algo, pkey->params,
+ pkey->paramlen);
+ if (ret)
+ goto error_free_tfm;
+
len = crypto_akcipher_maxsize(tfm);
info->key_size = len * 8;
info->max_data_size = len;
@@ -182,6 +188,11 @@ static int software_key_eds_op(struct kernel_pkey_params *params,
if (ret)
goto error_free_req;
+ ret = crypto_akcipher_set_params(tfm, pkey->algo, pkey->params,
+ pkey->paramlen);
+ if (ret)
+ goto error_free_req;
+
sg_init_one(&in_sg, in, params->in_len);
sg_init_one(&out_sg, out, params->out_len);
akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
@@ -263,6 +274,11 @@ int public_key_verify_signature(const struct public_key *pkey,
if (ret)
goto error_free_req;
+ ret = crypto_akcipher_set_params(tfm, pkey->algo, pkey->params,
+ pkey->paramlen);
+ if (ret)
+ goto error_free_req;
+
ret = -ENOMEM;
outlen = crypto_akcipher_maxsize(tfm);
output = kmalloc(outlen, GFP_KERNEL);
diff --git a/crypto/asymmetric_keys/x509.asn1 b/crypto/asymmetric_keys/x509.asn1
index aae0cde414e2..5c9f4e4a5231 100644
--- a/crypto/asymmetric_keys/x509.asn1
+++ b/crypto/asymmetric_keys/x509.asn1
@@ -22,7 +22,7 @@ CertificateSerialNumber ::= INTEGER
AlgorithmIdentifier ::= SEQUENCE {
algorithm OBJECT IDENTIFIER ({ x509_note_OID }),
- parameters ANY OPTIONAL
+ parameters ANY OPTIONAL ({ x509_note_params })
}
Name ::= SEQUENCE OF RelativeDistinguishedName
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 991f4d735a4e..16d8936d143b 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -26,6 +26,9 @@ struct x509_parse_context {
const void *cert_start; /* Start of cert content */
const void *key; /* Key data */
size_t key_size; /* Size of key data */
+ const void *params; /* Key parameters */
+ size_t params_size; /* Size of key parameters */
+ enum OID key_algo; /* Public key algorithm */
enum OID last_oid; /* Last OID encountered */
enum OID algo_oid; /* Algorithm OID */
unsigned char nr_mpi; /* Number of MPIs stored */
@@ -109,6 +112,13 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
cert->pub->keylen = ctx->key_size;
+ cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
+ if (!cert->pub->params)
+ goto error_decode;
+
+ cert->pub->paramlen = ctx->params_size;
+ cert->pub->algo = ctx->key_algo;
+
/* Grab the signature bits */
ret = x509_get_sig_params(cert);
if (ret < 0)
@@ -401,6 +411,23 @@ int x509_note_subject(void *context, size_t hdrlen,
}
/*
+ * Extract parameters for particular keys
+ */
+int x509_note_params(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ if (ctx->last_oid != OID_gost2012PublicKey256 &&
+ ctx->last_oid != OID_gost2012PublicKey512)
+ return 0;
+ ctx->params = value;
+ ctx->params_size = vlen;
+ return 0;
+}
+
+/*
* Extract the data for the public key algorithm
*/
int x509_extract_key_data(void *context, size_t hdrlen,
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 0f684a414acb..a030526a6609 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -2257,6 +2257,11 @@ static int test_akcipher_one(struct crypto_akcipher *tfm,
if (err)
goto free_req;
+ err = crypto_akcipher_set_params(tfm, vecs->algo, vecs->params,
+ vecs->param_len);
+ if (err)
+ goto free_req;
+
err = -ENOMEM;
out_len_max = crypto_akcipher_maxsize(tfm);
outbuf_enc = kzalloc(out_len_max, GFP_KERNEL);
diff --git a/crypto/testmgr.h b/crypto/testmgr.h
index e7e56a8febbc..9855da080eaf 100644
--- a/crypto/testmgr.h
+++ b/crypto/testmgr.h
@@ -124,13 +124,16 @@ struct drbg_testvec {
struct akcipher_testvec {
const unsigned char *key;
+ const unsigned char *params;
const unsigned char *m;
const unsigned char *c;
unsigned int key_len;
+ unsigned int param_len;
unsigned int m_size;
unsigned int c_size;
bool public_key_vec;
bool siggen_sigver_test;
+ enum OID algo;
};
struct kpp_testvec {
diff --git a/include/crypto/akcipher.h b/include/crypto/akcipher.h
index afac71119396..d6aba84ed2c4 100644
--- a/include/crypto/akcipher.h
+++ b/include/crypto/akcipher.h
@@ -13,6 +13,7 @@
#ifndef _CRYPTO_AKCIPHER_H
#define _CRYPTO_AKCIPHER_H
#include <linux/crypto.h>
+#include <linux/oid_registry.h>
/**
* struct akcipher_request - public key request
@@ -73,6 +74,9 @@ struct crypto_akcipher {
* @set_priv_key: Function invokes the algorithm specific set private key
* function, which knows how to decode and interpret
* the BER encoded private key
+ * @set_params: Function invokes the algorithm specific set parameters
+ * function, which knows how to decode and interpret
+ * the BER encoded public key
* @max_size: Function returns dest buffer size required for a given key.
* @init: Initialize the cryptographic transformation object.
* This function is used to initialize the cryptographic
@@ -98,6 +102,8 @@ struct akcipher_alg {
unsigned int keylen);
int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen);
+ int (*set_params)(struct crypto_akcipher *tfm, enum OID algo,
+ const void *params, unsigned int paramlen);
unsigned int (*max_size)(struct crypto_akcipher *tfm);
int (*init)(struct crypto_akcipher *tfm);
void (*exit)(struct crypto_akcipher *tfm);
@@ -452,4 +458,31 @@ static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm,
return alg->set_priv_key(tfm, key, keylen);
}
+
+/**
+ * crypto_akcipher_set_params() - Invoke set parameters operation
+ *
+ * Function invokes the algorithm specific set parameters function, which
+ * knows how to decode and interpret the encoded parameters
+ *
+ * @tfm: tfm handle
+ * @algo: OID of the key algorithm
+ * @params: BER encoded key parameters
+ * @paramlen: length of the parameters
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_akcipher_set_params(struct crypto_akcipher *tfm,
+ enum OID algo,
+ const void *params,
+ unsigned int paramlen)
+{
+ struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
+
+ if (alg->set_params)
+ return alg->set_params(tfm, algo, params, paramlen);
+ if (!params || !paramlen)
+ return 0;
+ return -ENOTSUPP;
+}
#endif
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index be626eac9113..712fe1214b5f 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -15,6 +15,7 @@
#define _LINUX_PUBLIC_KEY_H
#include <linux/keyctl.h>
+#include <linux/oid_registry.h>
/*
* Cryptographic data for the public-key subtype of the asymmetric key type.
@@ -25,6 +26,9 @@
struct public_key {
void *key;
u32 keylen;
+ enum OID algo;
+ void *params;
+ u32 paramlen;
bool key_is_private;
const char *id_type;
const char *pkey_algo;
diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index d2fa9ca42e9a..e2e323fd4826 100644
--- a/include/linux/oid_registry.h
+++ b/include/linux/oid_registry.h
@@ -93,6 +93,12 @@ enum OID {
OID_authorityKeyIdentifier, /* 2.5.29.35 */
OID_extKeyUsage, /* 2.5.29.37 */
+ /* EC-RDSA */
+ OID_gost2012PublicKey256, /* 1.2.643.7.1.1.1.1 */
+ OID_gost2012PublicKey512, /* 1.2.643.7.1.1.1.2 */
+ OID_gost2012Signature256, /* 1.2.643.7.1.1.3.2 */
+ OID_gost2012Signature512, /* 1.2.643.7.1.1.3.3 */
+
OID__NR
};
--
2.11.0