Merge #1650: schnorrsig: clear out masked secret key in BIP-340 nonce function

jonasnick · jonasnick · commit 00774d0723af · 2025-01-29T14:03:58.000Z
a82287f schnorrsig: clear out masked secret key in BIP-340 nonce function (Sebastian Falbesoner) Pull request description: ACKs for top commit: real-or-random: utACK a82287f jonasnick: ACK a82287f Tree-SHA512: 0e77ddc299e204edae238759e549d4e8314abb730a654580a109ec05daf53a625be1cc37664a9e00fd41cf34a94abede96b547e661cdf18c40c50141e7b4ee0e
diff --git a/src/modules/schnorrsig/main_impl.h b/src/modules/schnorrsig/main_impl.h
@@ -94,6 +94,8 @@ static int nonce_function_bip340(unsigned char *nonce32, const unsigned char *ms
     secp256k1_sha256_write(&sha, msg, msglen);
     secp256k1_sha256_finalize(&sha, nonce32);
     secp256k1_sha256_clear(&sha);
+    secp256k1_memclear(masked_key, sizeof(masked_key));
+
     return 1;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -94,6 +94,8 @@ static int nonce_function_bip340(unsigned char nonce32, const unsigned char ms`
`94`	`94`	`secp256k1_sha256_write(&sha, msg, msglen);`
`95`	`95`	`secp256k1_sha256_finalize(&sha, nonce32);`
`96`	`96`	`secp256k1_sha256_clear(&sha);`
	`97`	`+ secp256k1_memclear(masked_key, sizeof(masked_key));`
	`98`	`+`
`97`	`99`	`return 1;`
`98`	`100`	`}`
`99`	`101`