diff options
Diffstat (limited to 'g10/ecdh.c')
| -rw-r--r-- | g10/ecdh.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/g10/ecdh.c b/g10/ecdh.c index 9576a1c1a..a1b7ecfdc 100644 --- a/g10/ecdh.c +++ b/g10/ecdh.c @@ -134,9 +134,12 @@ pk_ecdh_encrypt_with_shared_point (int is_encrypt, gcry_mpi_t shared_mpi, } secret_x_size = (nbits+7)/8; - assert (nbytes > secret_x_size); - memmove (secret_x, secret_x+1, secret_x_size); - memset (secret_x+secret_x_size, 0, nbytes-secret_x_size); + assert (nbytes >= secret_x_size); + if ((nbytes & 1)) + /* Remove the "04" prefix of non-compressed format. */ + memmove (secret_x, secret_x+1, secret_x_size); + if (nbytes - secret_x_size) + memset (secret_x+secret_x_size, 0, nbytes-secret_x_size); if (DBG_CRYPTO) log_printhex ("ECDH shared secret X is:", secret_x, secret_x_size ); |