summaryrefslogtreecommitdiff
path: root/src/crypto/evp/p_x25519_asn1.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/crypto/evp/p_x25519_asn1.c')
-rw-r--r--src/crypto/evp/p_x25519_asn1.c249
1 files changed, 249 insertions, 0 deletions
diff --git a/src/crypto/evp/p_x25519_asn1.c b/src/crypto/evp/p_x25519_asn1.c
new file mode 100644
index 00000000..90256235
--- /dev/null
+++ b/src/crypto/evp/p_x25519_asn1.c
@@ -0,0 +1,249 @@
+/* Copyright (c) 2019, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/evp.h>
+
+#include <openssl/buf.h>
+#include <openssl/bytestring.h>
+#include <openssl/curve25519.h>
+#include <openssl/err.h>
+#include <openssl/mem.h>
+
+#include "internal.h"
+#include "../internal.h"
+
+
+static void x25519_free(EVP_PKEY *pkey) {
+ OPENSSL_free(pkey->pkey.ptr);
+ pkey->pkey.ptr = NULL;
+}
+
+static int x25519_set_priv_raw(EVP_PKEY *pkey, const uint8_t *in, size_t len) {
+ if (len != 32) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
+ return 0;
+ }
+
+ X25519_KEY *key = OPENSSL_malloc(sizeof(X25519_KEY));
+ if (key == NULL) {
+ OPENSSL_PUT_ERROR(EVP, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+
+ OPENSSL_memcpy(key->priv, in, 32);
+ X25519_public_from_private(key->pub, key->priv);
+ key->has_private = 1;
+
+ x25519_free(pkey);
+ pkey->pkey.ptr = key;
+ return 1;
+}
+
+static int x25519_set_pub_raw(EVP_PKEY *pkey, const uint8_t *in, size_t len) {
+ if (len != 32) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
+ return 0;
+ }
+
+ X25519_KEY *key = OPENSSL_malloc(sizeof(X25519_KEY));
+ if (key == NULL) {
+ OPENSSL_PUT_ERROR(EVP, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+
+ OPENSSL_memcpy(key->pub, in, 32);
+ key->has_private = 0;
+
+ x25519_free(pkey);
+ pkey->pkey.ptr = key;
+ return 1;
+}
+
+static int x25519_get_priv_raw(const EVP_PKEY *pkey, uint8_t *out,
+ size_t *out_len) {
+ const X25519_KEY *key = pkey->pkey.ptr;
+ if (!key->has_private) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_NOT_A_PRIVATE_KEY);
+ return 0;
+ }
+
+ if (out == NULL) {
+ *out_len = 32;
+ return 1;
+ }
+
+ if (*out_len < 32) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+
+ OPENSSL_memcpy(out, key->priv, 32);
+ *out_len = 32;
+ return 1;
+}
+
+static int x25519_get_pub_raw(const EVP_PKEY *pkey, uint8_t *out,
+ size_t *out_len) {
+ const X25519_KEY *key = pkey->pkey.ptr;
+ if (out == NULL) {
+ *out_len = 32;
+ return 1;
+ }
+
+ if (*out_len < 32) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+
+ OPENSSL_memcpy(out, key->pub, 32);
+ *out_len = 32;
+ return 1;
+}
+
+static int x25519_pub_decode(EVP_PKEY *out, CBS *params, CBS *key) {
+ // See RFC 8410, section 4.
+
+ // The parameters must be omitted. Public keys have length 32.
+ if (CBS_len(params) != 0) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
+ return 0;
+ }
+
+ return x25519_set_pub_raw(out, CBS_data(key), CBS_len(key));
+}
+
+static int x25519_pub_encode(CBB *out, const EVP_PKEY *pkey) {
+ const X25519_KEY *key = pkey->pkey.ptr;
+
+ // See RFC 8410, section 4.
+ CBB spki, algorithm, oid, key_bitstring;
+ if (!CBB_add_asn1(out, &spki, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1(&spki, &algorithm, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
+ !CBB_add_bytes(&oid, x25519_asn1_meth.oid, x25519_asn1_meth.oid_len) ||
+ !CBB_add_asn1(&spki, &key_bitstring, CBS_ASN1_BITSTRING) ||
+ !CBB_add_u8(&key_bitstring, 0 /* padding */) ||
+ !CBB_add_bytes(&key_bitstring, key->pub, 32) ||
+ !CBB_flush(out)) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR);
+ return 0;
+ }
+
+ return 1;
+}
+
+static int x25519_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b) {
+ const X25519_KEY *a_key = a->pkey.ptr;
+ const X25519_KEY *b_key = b->pkey.ptr;
+ return OPENSSL_memcmp(a_key->pub, b_key->pub, 32) == 0;
+}
+
+static int x25519_priv_decode(EVP_PKEY *out, CBS *params, CBS *key) {
+ // See RFC 8410, section 7.
+
+ // Parameters must be empty. The key is a 32-byte value wrapped in an extra
+ // OCTET STRING layer.
+ CBS inner;
+ if (CBS_len(params) != 0 ||
+ !CBS_get_asn1(key, &inner, CBS_ASN1_OCTETSTRING) ||
+ CBS_len(key) != 0) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
+ return 0;
+ }
+
+ return x25519_set_priv_raw(out, CBS_data(&inner), CBS_len(&inner));
+}
+
+static int x25519_priv_encode(CBB *out, const EVP_PKEY *pkey) {
+ X25519_KEY *key = pkey->pkey.ptr;
+ if (!key->has_private) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_NOT_A_PRIVATE_KEY);
+ return 0;
+ }
+
+ // See RFC 8410, section 7.
+ CBB pkcs8, algorithm, oid, private_key, inner;
+ if (!CBB_add_asn1(out, &pkcs8, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1_uint64(&pkcs8, 0 /* version */) ||
+ !CBB_add_asn1(&pkcs8, &algorithm, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
+ !CBB_add_bytes(&oid, x25519_asn1_meth.oid, x25519_asn1_meth.oid_len) ||
+ !CBB_add_asn1(&pkcs8, &private_key, CBS_ASN1_OCTETSTRING) ||
+ !CBB_add_asn1(&private_key, &inner, CBS_ASN1_OCTETSTRING) ||
+ // The PKCS#8 encoding stores only the 32-byte seed which is the first 32
+ // bytes of the private key.
+ !CBB_add_bytes(&inner, key->priv, 32) ||
+ !CBB_flush(out)) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR);
+ return 0;
+ }
+
+ return 1;
+}
+
+static int x25519_size(const EVP_PKEY *pkey) { return 32; }
+
+static int x25519_bits(const EVP_PKEY *pkey) { return 253; }
+
+const EVP_PKEY_ASN1_METHOD x25519_asn1_meth = {
+ EVP_PKEY_X25519,
+ {0x2b, 0x65, 0x6e},
+ 3,
+ x25519_pub_decode,
+ x25519_pub_encode,
+ x25519_pub_cmp,
+ x25519_priv_decode,
+ x25519_priv_encode,
+ x25519_set_priv_raw,
+ x25519_set_pub_raw,
+ x25519_get_priv_raw,
+ x25519_get_pub_raw,
+ NULL /* pkey_opaque */,
+ x25519_size,
+ x25519_bits,
+ NULL /* param_missing */,
+ NULL /* param_copy */,
+ NULL /* param_cmp */,
+ x25519_free,
+};
+
+int EVP_PKEY_set1_tls_encodedpoint(EVP_PKEY *pkey, const uint8_t *in,
+ size_t len) {
+ // TODO(davidben): In OpenSSL, this function also works for |EVP_PKEY_EC|
+ // keys. Add support if it ever comes up.
+ if (pkey->type != EVP_PKEY_X25519) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
+ return 0;
+ }
+
+ return x25519_set_pub_raw(pkey, in, len);
+}
+
+size_t EVP_PKEY_get1_tls_encodedpoint(const EVP_PKEY *pkey, uint8_t **out_ptr) {
+ // TODO(davidben): In OpenSSL, this function also works for |EVP_PKEY_EC|
+ // keys. Add support if it ever comes up.
+ if (pkey->type != EVP_PKEY_X25519) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
+ return 0;
+ }
+
+ const X25519_KEY *key = pkey->pkey.ptr;
+ if (key == NULL) {
+ OPENSSL_PUT_ERROR(EVP, EVP_R_NO_KEY_SET);
+ return 0;
+ }
+
+ *out_ptr = BUF_memdup(key->pub, 32);
+ return *out_ptr == NULL ? 0 : 32;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-26 08:59:28 +0000