modules/crypto/argon2d: reduce size of sscanf(3) buffers

0x2000 (8 KiB) is definitely sufficient to mitigate any potential
inadvertant overflow, and an attacker with a crafted malicious
database would have been able to overflow the old 0x8000 (32 KiB)
buffers anyway.

diff --git a/modules/crypto/argon2d.c b/modules/crypto/argon2d.c
index 84c25d2f6dcf79796f2701969a28fa0dc4f18695..1ba96fb31953df0f44ff1dff13d20c60d5e05f45 100644 (file)
--- a/modules/crypto/argon2d.c
+++ b/modules/crypto/argon2d.c
@@ -761,7 +761,7 @@ atheme_argon2d_salt(void)
        uint8_t salt[ATHEME_ARGON2D_SALTLEN];
        (void) arc4random_buf(salt, sizeof salt);
 
-       char salt_b64[0x8000];
+       char salt_b64[0x2000];
        (void) argon2d_enc_b64(salt, sizeof salt, salt_b64);
 
        static char res[PASSLEN];
@@ -777,7 +777,7 @@ atheme_argon2d_crypt(const char *const restrict pass, const char *const restrict
        struct argon2d_context ctx;
        (void) memset(&ctx, 0x00, sizeof ctx);
 
-       char salt_b64[0x8000];
+       char salt_b64[0x2000];
        if (sscanf(encoded, ATHEME_ARGON2D_LOADSALT, &ctx.m_cost, &ctx.t_cost, salt_b64) != 3)
                return NULL;
 
@@ -793,7 +793,7 @@ atheme_argon2d_crypt(const char *const restrict pass, const char *const restrict
        if (!argon2d_hash_raw(&ctx))
                return NULL;
 
-       char hash_b64[0x8000];
+       char hash_b64[0x2000];
        (void) argon2d_enc_b64(ctx.hash, sizeof ctx.hash, hash_b64);
 
        static char res[PASSLEN];
@@ -808,7 +808,7 @@ atheme_argon2d_upgrade(const char *const restrict encoded)
 {
        uint32_t m_cost;
        uint32_t t_cost;
-       char salt_b64[0x8000];
+       char salt_b64[0x2000];
        if (sscanf(encoded, ATHEME_ARGON2D_LOADSALT, &m_cost, &t_cost, salt_b64) != 3)
                return false;