OpenSSL's implementation of ED448 and ED25519 has a few idiosyncrasies.
Instead of belonging to the eliptic curve type or to a common Edwards
curve type, ED448 and ED25519 have each their own type.
Also, OpenSSL expects signatures using these curves to be done with the
EVP_DigestSign API instead of the EVP_Sign API but using md=NULL.
This has been tested using a "fake" external key that used a normal
software key instead of a hardware implementation but that makes no
difference from the perspective of xkey_provider/management interface.
Patch v2: remove name functions from ed448/ed25519, ensure md is NULL
for ed448/ed25519 and handle NULL/none better in general.
---
src/openvpn/xkey_common.h | 2 +-
src/openvpn/xkey_helper.c | 7 +-
src/openvpn/xkey_provider.c | 97 ++++++++++++++++++++++--
tests/unit_tests/openvpn/test_provider.c | 37 +++++++--
4 files changed, 127 insertions(+), 16 deletions(-)
diff --git a/src/openvpn/xkey_common.h b/src/openvpn/xkey_common.h
index 35cbcf576..e0e5ed5b2 100644
--- a/src/openvpn/xkey_common.h
+++ b/src/openvpn/xkey_common.h
@@ -43,7 +43,7 @@ OSSL_provider_init_fn xkey_provider_init;
#define XKEY_PROV_PROPS "provider=ovpn.xkey"
/**
- * Stuct to encapsulate signature algorithm parameters to pass
+ * Struct to encapsulate signature algorithm parameters to pass
* to sign operation.
*/
typedef struct {
diff --git a/src/openvpn/xkey_helper.c b/src/openvpn/xkey_helper.c
index ecc7b1204..f47f7ffc7 100644
--- a/src/openvpn/xkey_helper.c
+++ b/src/openvpn/xkey_helper.c
@@ -179,7 +179,8 @@ xkey_management_sign(void *unused, unsigned char *sig,
size_t *siglen,
bool is_message = !strcmp(alg.op, "DigestSign"); /* tbs is message, not
digest */
/* if management client cannot do digest -- we do it here */
- if (!strcmp(alg.op, "DigestSign") && !(flags & MF_EXTERNAL_KEY_DIGEST))
+ if (!strcmp(alg.op, "DigestSign") && !(flags & MF_EXTERNAL_KEY_DIGEST)
+ && strcmp(alg.mdname, "none") != 0)
{
dmsg(D_XKEY, "xkey_management_sign: computing digest");
if (xkey_digest(tbs, tbslen, buf, &buflen, alg.mdname))
@@ -206,6 +207,10 @@ xkey_management_sign(void *unused, unsigned char *sig,
size_t *siglen,
openvpn_snprintf(alg_str, sizeof(alg_str), "ECDSA,hashalg=%s",
alg.mdname);
}
}
+ else if (!strcmp(alg.keytype, "ED448") || !strcmp(alg.keytype, "ED25519"))
+ {
+ strncpynt(alg_str, alg.keytype, sizeof(alg_str));
+ }
/* else assume RSA key */
else if (!strcmp(alg.padmode, "pkcs1") && (flags &
MF_EXTERNAL_KEY_PKCS1PAD))
{
diff --git a/src/openvpn/xkey_provider.c b/src/openvpn/xkey_provider.c
index 46e57e0fe..67000004e 100644
--- a/src/openvpn/xkey_provider.c
+++ b/src/openvpn/xkey_provider.c
@@ -99,12 +99,28 @@ typedef struct
int refcount; /**< reference count */
} XKEY_KEYDATA;
-static int
-KEYTYPE(const XKEY_KEYDATA *key)
+static inline const char *
+get_keytype(const XKEY_KEYDATA *key)
{
- return key->pubkey ? EVP_PKEY_get_id(key->pubkey) : 0;
+ int keytype = key->pubkey ? EVP_PKEY_get_id(key->pubkey) : 0;
+
+ switch (keytype)
+ {
+ case EVP_PKEY_RSA:
+ return "RSA";
+
+ case EVP_PKEY_ED448:
+ return "ED448";
+
+ case EVP_PKEY_ED25519:
+ return "ED25519";
+
+ default:
+ return "EC";
+ }
}
+
static int
KEYSIZE(const XKEY_KEYDATA *key)
{
@@ -310,6 +326,22 @@ ec_keymgmt_import(void *keydata, int selection, const
OSSL_PARAM params[])
return keymgmt_import(keydata, selection, params, "EC");
}
+static int
+ed448_keymgmt_import(void *keydata, int selection, const OSSL_PARAM params[])
+{
+ xkey_dmsg(D_XKEY, "entry");
+
+ return keymgmt_import(keydata, selection, params, "ED448");
+}
+
+static int
+ed25519_keymgmt_import(void *keydata, int selection, const OSSL_PARAM params[])
+{
+ xkey_dmsg(D_XKEY, "entry");
+
+ return keymgmt_import(keydata, selection, params, "ED25519");
+}
+
/* This function has to exist for key import to work
* though we do not support import of individual params
* like n or e. We simply return an empty list here for
@@ -449,7 +481,7 @@ keymgmt_import_helper(XKEY_KEYDATA *key, const OSSL_PARAM
*params)
ASSERT(pkey);
int id = EVP_PKEY_get_id(pkey);
- if (id != EVP_PKEY_RSA && id != EVP_PKEY_EC)
+ if (id != EVP_PKEY_RSA && id != EVP_PKEY_EC && id != EVP_PKEY_ED25519
&& id != EVP_PKEY_ED448)
{
msg(M_WARN, "Error: xkey keymgmt_import: unknown key type (%d)",
id);
return 0;
@@ -588,10 +620,43 @@ static const OSSL_DISPATCH ec_keymgmt_functions[] = {
{0, NULL }
};
+static const OSSL_DISPATCH ed448_keymgmt_functions[] = {
+ {OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))keymgmt_new},
+ {OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))keymgmt_free},
+ {OSSL_FUNC_KEYMGMT_LOAD, (void (*)(void))keymgmt_load},
+ {OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))keymgmt_has},
+ {OSSL_FUNC_KEYMGMT_MATCH, (void (*)(void))keymgmt_match},
+ {OSSL_FUNC_KEYMGMT_IMPORT, (void (*)(void))ed448_keymgmt_import},
+ {OSSL_FUNC_KEYMGMT_IMPORT_TYPES, (void (*)(void))keymgmt_import_types},
+ {OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS, (void
(*)(void))keymgmt_gettable_params},
+ {OSSL_FUNC_KEYMGMT_GET_PARAMS, (void (*)(void))keymgmt_get_params},
+ {OSSL_FUNC_KEYMGMT_SET_PARAMS, (void (*)(void))keymgmt_set_params},
+ {OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS, (void
(*)(void))keymgmt_gettable_params}, /* same as gettable */
+ {0, NULL }
+};
+
+static const OSSL_DISPATCH ed25519_keymgmt_functions[] = {
+ {OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))keymgmt_new},
+ {OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))keymgmt_free},
+ {OSSL_FUNC_KEYMGMT_LOAD, (void (*)(void))keymgmt_load},
+ {OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))keymgmt_has},
+ {OSSL_FUNC_KEYMGMT_MATCH, (void (*)(void))keymgmt_match},
+ {OSSL_FUNC_KEYMGMT_IMPORT, (void (*)(void))ed25519_keymgmt_import},
+ {OSSL_FUNC_KEYMGMT_IMPORT_TYPES, (void (*)(void))keymgmt_import_types},
+ {OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS, (void
(*)(void))keymgmt_gettable_params},
+ {OSSL_FUNC_KEYMGMT_GET_PARAMS, (void (*)(void))keymgmt_get_params},
+ {OSSL_FUNC_KEYMGMT_SET_PARAMS, (void (*)(void))keymgmt_set_params},
+ {OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS, (void
(*)(void))keymgmt_gettable_params}, /* same as gettable */
+ {0, NULL }
+};
+
+
const OSSL_ALGORITHM keymgmts[] = {
{"RSA:rsaEncryption", XKEY_PROV_PROPS, rsa_keymgmt_functions, "OpenVPN
xkey RSA Key Manager"},
{"RSA-PSS:RSASSA-PSS", XKEY_PROV_PROPS, rsa_keymgmt_functions, "OpenVPN
xkey RSA-PSS Key Manager"},
{"EC:id-ecPublicKey", XKEY_PROV_PROPS, ec_keymgmt_functions, "OpenVPN xkey
EC Key Manager"},
+ {"ED448", XKEY_PROV_PROPS, ed448_keymgmt_functions, "OpenVPN xkey ED448
Key Manager"},
+ {"ED25519", XKEY_PROV_PROPS, ed25519_keymgmt_functions, "OpenVPN xkey
ED25519 Key Manager"},
{NULL, NULL, NULL, NULL}
};
@@ -649,6 +714,11 @@ static const char *saltlen_names[] = {"digest", "max",
"auto", NULL};
static const char *
xkey_mdname(const char *name)
{
+ if (name == NULL)
+ {
+ return "none";
+ }
+
int i = 0;
int nid = EVP_MD_get_type(EVP_get_digestbyname(name));
@@ -835,7 +905,7 @@ signature_sign_init(void *ctx, void *provkey, const
OSSL_PARAM params[])
}
sctx->keydata = provkey;
sctx->keydata->refcount++; /* we are keeping a copy */
- sctx->sigalg.keytype = KEYTYPE(sctx->keydata) == EVP_PKEY_RSA ? "RSA" :
"EC";
+ sctx->sigalg.keytype = get_keytype(sctx->keydata);
signature_set_ctx_params(sctx, params);
@@ -929,10 +999,21 @@ signature_digest_sign_init(void *ctx, const char *mdname,
}
sctx->keydata = provkey; /* used by digest_sign */
sctx->keydata->refcount++;
- sctx->sigalg.keytype = KEYTYPE(sctx->keydata) == EVP_PKEY_RSA ? "RSA" :
"EC";
+ sctx->sigalg.keytype = get_keytype(sctx->keydata);
signature_set_ctx_params(ctx, params);
- if (mdname)
+ if (!strcmp(sctx->sigalg.keytype, "ED448") ||
!strcmp(sctx->sigalg.keytype, "ED25519"))
+ {
+ /* EdDSA requires NULL as digest for the DigestSign API instead
+ * of using the normal Sign API. Ensure it is actually NULL too */
+ if (mdname != NULL)
+ {
+ msg(M_WARN, "xkey digest_sign_init: mdname must be NULL for
ED448/ED25519.");
+ return 0;
+ }
+ sctx->sigalg.mdname = "none";
+ }
+ else if (mdname)
{
sctx->sigalg.mdname = xkey_mdname(mdname); /* get a string literal
pointer */
}
@@ -1073,6 +1154,8 @@ static const OSSL_DISPATCH signature_functions[] = {
const OSSL_ALGORITHM signatures[] = {
{"RSA:rsaEncryption", XKEY_PROV_PROPS, signature_functions, "OpenVPN xkey
RSA Signature"},
{"ECDSA", XKEY_PROV_PROPS, signature_functions, "OpenVPN xkey ECDSA
Signature"},
+ {"ED448", XKEY_PROV_PROPS, signature_functions, "OpenVPN xkey Ed448
Signature"},
+ {"ED25519", XKEY_PROV_PROPS, signature_functions, "OpenVPN xkey Ed25519
Signature"},
{NULL, NULL, NULL, NULL}
};
diff --git a/tests/unit_tests/openvpn/test_provider.c
b/tests/unit_tests/openvpn/test_provider.c
index 0b0952ee2..86009b155 100644
--- a/tests/unit_tests/openvpn/test_provider.c
+++ b/tests/unit_tests/openvpn/test_provider.c
@@ -66,7 +66,11 @@ static const char *const pubkey2 = "-----BEGIN PUBLIC
KEY-----\n"
"u95ff1JiUaJIkYNIkZA+hwIPFVH5aJcSCv3SPIeDS2VUAESNKHZJBQ==\n"
"-----END PUBLIC KEY-----\n";
-static const char *pubkeys[] = {pubkey1, pubkey2};
+static const char *const pubkey3 = "-----BEGIN PUBLIC KEY-----\n"
+
"MCowBQYDK2VwAyEA+q5xjF5hGyyqYZidJdz/0saEQabL3N4wIZJBxNGbgJE=\n"
+ "-----END PUBLIC KEY-----";
+
+static const char *pubkeys[] = {pubkey1, pubkey2, pubkey3};
static const char *prov_name = "ovpn.xkey";
@@ -158,12 +162,17 @@ management_query_pk_sig(struct management *man, const
char *b64_data,
if (strstr(algorithm, "data=message"))
{
expected_tbs = test_msg_b64;
- assert_non_null(strstr(algorithm, "hashalg=SHA256"));
+ /* ED25519 does not have a hash algorithm even though it goes via
+ * the DigestSign path (data=message) */
+ if (!strstr(algorithm, "ED25519"))
+ {
+ assert_non_null(strstr(algorithm, "hashalg=SHA256"));
+ }
}
assert_string_equal(b64_data, expected_tbs);
- /* We test using ECDSA or PSS with saltlen = digest */
- if (!strstr(algorithm, "ECDSA"))
+ /* We test using ED25519, ECDSA or PSS with saltlen = digest */
+ if (!strstr(algorithm, "ECDSA") && !strstr(algorithm, "ED25519"))
{
assert_non_null(strstr(algorithm,
"RSA_PKCS1_PSS_PADDING,hashalg=SHA256,saltlen=digest"));
}
@@ -228,6 +237,13 @@ digest_sign(EVP_PKEY *pkey)
params[3] =
OSSL_PARAM_construct_utf8_string(OSSL_SIGNATURE_PARAM_MGF1_DIGEST, (char
*)saltlen, 0);
params[4] = OSSL_PARAM_construct_end();
}
+ else if (EVP_PKEY_get_id(pkey) == EVP_PKEY_ED25519)
+ {
+ mdname = NULL;
+ params[0] =
OSSL_PARAM_construct_utf8_string(OSSL_SIGNATURE_PARAM_DIGEST, (char *)mdname,
0);
+ params[1] = OSSL_PARAM_construct_end();
+ }
+
EVP_PKEY_CTX *pctx = NULL;
EVP_MD_CTX *mctx = EVP_MD_CTX_new();
@@ -328,13 +344,20 @@ xkey_sign(void *handle, unsigned char *sig, size_t
*siglen,
assert_memory_equal(tbs, test_digest, sizeof(test_digest));
}
- /* For the test use sha256 and PSS padding for RSA */
- assert_int_equal(OBJ_sn2nid(s.mdname), NID_sha256);
+ /* For the test use sha256 and PSS padding for RSA and none for EDDSA */
+ if (!strcmp(s.keytype,"ED25519"))
+ {
+ assert_string_equal(s.mdname, "none");
+ }
+ else
+ {
+ assert_int_equal(OBJ_sn2nid(s.mdname), NID_sha256);
+ }
if (!strcmp(s.keytype, "RSA"))
{
assert_string_equal(s.padmode, "pss"); /* we use PSS for the test */
}
- else if (strcmp(s.keytype, "EC"))
+ else if (strcmp(s.keytype, "EC") && strcmp(s.keytype,"ED25519"))
{
fail_msg("Unknown keytype: %s", s.keytype);
}
--
2.32.0 (Apple Git-132)
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