musig: update to BIP v0.5.1 "Rename ordinary tweaking to plain"

examples/musig.c

@@ -55,13 +55,13 @@ int create_keypair(const secp256k1_context* ctx, struct signer_secrets *signer_s
  * and return the tweaked aggregate pk. */
 int tweak(const secp256k1_context* ctx, secp256k1_xonly_pubkey *agg_pk, secp256k1_musig_keyagg_cache *cache) {
     secp256k1_pubkey output_pk;
-    unsigned char ordinary_tweak[32] = "this could be a BIP32 tweak....";
+    unsigned char plain_tweak[32] = "this could be a BIP32 tweak....";
     unsigned char xonly_tweak[32] = "this could be a taproot tweak..";
 
 
-    /* Ordinary tweaking which, for example, allows deriving multiple child
+    /* Plain tweaking which, for example, allows deriving multiple child
      * public keys from a single aggregate key using BIP32 */
-    if (!secp256k1_musig_pubkey_ec_tweak_add(ctx, NULL, cache, ordinary_tweak)) {
+    if (!secp256k1_musig_pubkey_ec_tweak_add(ctx, NULL, cache, plain_tweak)) {
         return 0;
     }
     /* Note that we did not provided an output_pk argument, because the

include/secp256k1_musig.h

@@ -226,7 +226,7 @@ SECP256K1_API int secp256k1_musig_pubkey_agg(
 /** Obtain the aggregate public key from a keyagg_cache.
  *
  *  This is only useful if you need the non-xonly public key, in particular for
- *  ordinary (non-xonly) tweaking or batch-verifying multiple key aggregations
+ *  plain (non-xonly) tweaking or batch-verifying multiple key aggregations
  *  (not implemented).
  *
  *  Returns: 0 if the arguments are invalid, 1 otherwise
@@ -241,7 +241,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_musig_pubkey_get(
     secp256k1_musig_keyagg_cache *keyagg_cache
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
-/** Apply ordinary "EC" tweaking to a public key in a given keyagg_cache by
+/** Apply plain "EC" tweaking to a public key in a given keyagg_cache by
  *  adding the generator multiplied with `tweak32` to it. This is useful for
  *  deriving child keys from an aggregate public key via BIP32.
  *

src/modules/musig/musig.md

@@ -23,7 +23,7 @@ Therefore, users of the musig module must take great care to make sure of the fo
 # Key Aggregation and (Taproot) Tweaking
 
 Given a set of public keys, the aggregate public key is computed with `secp256k1_musig_pubkey_agg`.
-A (Taproot) tweak can be added to the resulting public key with `secp256k1_xonly_pubkey_tweak_add` and an ordinary tweak can be added with `secp256k1_ec_pubkey_tweak_add`.
+A (Taproot) tweak can be added to the resulting public key with `secp256k1_xonly_pubkey_tweak_add` and a plain tweak can be added with `secp256k1_ec_pubkey_tweak_add`.
 
 # Signing
 
@@ -32,7 +32,7 @@ Essentially, the protocol proceeds in the following steps:
 
 1. Generate a keypair with `secp256k1_keypair_create` and obtain the xonly public key with `secp256k1_keypair_xonly_pub`.
 2. Call `secp256k1_musig_pubkey_agg` with the xonly pubkeys of all participants.
-3. Optionally add a (Taproot) tweak with `secp256k1_musig_pubkey_xonly_tweak_add` and an ordinary tweak with `secp256k1_musig_pubkey_ec_tweak_add`.
+3. Optionally add a (Taproot) tweak with `secp256k1_musig_pubkey_xonly_tweak_add` and a plain tweak with `secp256k1_musig_pubkey_ec_tweak_add`.
 4. Generate a pair of secret and public nonce with `secp256k1_musig_nonce_gen` and send the public nonce to the other signers.
 5. Someone (not necessarily the signer) aggregates the public nonce with `secp256k1_musig_nonce_agg` and sends it to the signers.
 6. Process the aggregate nonce with `secp256k1_musig_nonce_process`.

src/modules/musig/tests_impl.h

@@ -857,7 +857,7 @@ void musig_tweak_test_helper(const secp256k1_xonly_pubkey* agg_pk, const unsigne
 }
 
 /* Create aggregate public key P[0], tweak multiple times (using xonly and
- * ordinary tweaking) and test signing. */
+ * plain tweaking) and test signing. */
 void musig_tweak_test(secp256k1_scratch_space *scratch) {
     unsigned char sk[2][32];
     secp256k1_xonly_pubkey pk[2];