NR_Verification_Operation::verify_mr would return false if the input

was not the right size for a signature (following DSA). This would
silently convert to an empty vector which we would treat as a valid
message on the return. However the EMSA checks will always fail so not
a huge problem.

While checking this out I noticed that an empty value for EMSA4 would
result in us reading memory we didn't own.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/pubkey/nr/nr.cpp b/src/pubkey/nr/nr.cpp
index 61cf7eb3f..03885e140 100644
--- a/src/pubkey/nr/nr.cpp
+++ b/src/pubkey/nr/nr.cpp
@@ -124,7 +124,7 @@ NR_Verification_Operation::verify_mr(const byte msg[], size_t msg_len)
    const BigInt& q = mod_q.get_modulus();
 
    if(msg_len != 2*q.bytes())
-      return false;
+      throw Invalid_Argument("NR verification: Invalid signature");
 
    BigInt c(msg, q.bytes());
    BigInt d(msg + q.bytes(), q.bytes());