Add the suite of EC_KEY and EC_POINT serializers.
OpenSSL added a bunch of these. oct2priv is a little weird (see
https://crbug.com/boringssl/534), but I've made it match OpenSSL and
set_private_key for now. But I think we should reduce the state-space a
bit.
EC_KEY_oct2priv behaves slightly differently from upstream OpenSSL in
one way: we reject inputs that aren't exactly the right size. This
matches the OpenSSL documentation (the OCTET STRING inside an
ECPrivateKey, per spec, is fixed-width), but not OpenSSL's behavior.
Update-note: see go/xshow when incorporating this change internally.
Change-Id: I33863d773ac4c7f3eabf4ffda157e8250c7fdbd9
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/55066
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/include/openssl/ec_key.h b/include/openssl/ec_key.h
index 3143290..ee9c9f0 100644
--- a/include/openssl/ec_key.h
+++ b/include/openssl/ec_key.h
@@ -186,12 +186,31 @@
OPENSSL_EXPORT int EC_KEY_oct2key(EC_KEY *key, const uint8_t *in, size_t len,
BN_CTX *ctx);
-// EC_KEY_key2buf encodes the public key in |key| to an allocated octet string
-// and sets |*out_buf| to point to it. It returns the length of the encoded
-// octet string or zero if an error occurred.
+// EC_KEY_key2buf behaves like |EC_POINT_point2buf|, except it encodes the
+// public key in |key|.
OPENSSL_EXPORT size_t EC_KEY_key2buf(const EC_KEY *key,
point_conversion_form_t form,
- unsigned char **out_buf, BN_CTX *ctx);
+ uint8_t **out_buf, BN_CTX *ctx);
+
+// EC_KEY_oct2priv decodes a big-endian, zero-padded integer from |len| bytes
+// from |in| and sets |key|'s private key to the result. It returns one on
+// success and zero on error. The input must be padded to the size of |key|'s
+// group order.
+OPENSSL_EXPORT int EC_KEY_oct2priv(EC_KEY *key, const uint8_t *in, size_t len);
+
+// EC_KEY_priv2oct serializes |key|'s private key as a big-endian integer,
+// zero-padded to the size of |key|'s group order and writes the result to at
+// most |max_out| bytes of |out|. It returns the number of bytes written on
+// success and zero on error. If |out| is NULL, it returns the number of bytes
+// needed without writing anything.
+OPENSSL_EXPORT size_t EC_KEY_priv2oct(const EC_KEY *key, uint8_t *out,
+ size_t max_out);
+
+// EC_KEY_priv2buf behaves like |EC_KEY_priv2oct| but sets |*out_buf| to a
+// newly-allocated buffer containing the result. It returns the size of the
+// result on success and zero on error. The caller must release |*out_buf| with
+// |OPENSSL_free| when done.
+OPENSSL_EXPORT size_t EC_KEY_priv2buf(const EC_KEY *key, uint8_t **out_buf);
// Key generation.
