crypto: Clear temporary heap allocations before freeing

This reduces the time private keys may remain in heap memory after use.

Signed-off-by: Jouni Malinen <j@w1.fi>

diff --git a/hostapd/Makefile b/hostapd/Makefile
index e64c249..ef1aa6f 100644 (file)
--- a/hostapd/Makefile
+++ b/hostapd/Makefile
@@ -962,6 +962,7 @@ hostapd_cli: $(OBJS_c)
        @$(E) "  LD " $@
 
 NOBJS = nt_password_hash.o ../src/crypto/ms_funcs.o $(SHA1OBJS) ../src/crypto/md5.o
+NOBJS += ../src/utils/common.o
 ifdef NEED_RC4
 ifdef CONFIG_INTERNAL_RC4
 NOBJS += ../src/crypto/rc4.o

diff --git a/src/crypto/aes-eax.c b/src/crypto/aes-eax.c
index 21941c6..15a09f8 100644 (file)
--- a/src/crypto/aes-eax.c
+++ b/src/crypto/aes-eax.c
@@ -71,7 +71,7 @@ int aes_128_eax_encrypt(const u8 *key, const u8 *nonce, size_t nonce_len,
 
        ret = 0;
 fail:
-       os_free(buf);
+       bin_clear_free(buf, buf_len);
 
        return ret;
 }

diff --git a/src/crypto/aes-siv.c b/src/crypto/aes-siv.c
index 0a82ddc..5ac82c2 100644 (file)
--- a/src/crypto/aes-siv.c
+++ b/src/crypto/aes-siv.c
@@ -95,7 +95,7 @@ static int aes_s2v(const u8 *key, size_t num_elem, const u8 *addr[],
                os_memcpy(buf, addr[i], len[i]);
                xorend(buf, len[i], tmp, AES_BLOCK_SIZE);
                ret = omac1_aes_128(key, buf, len[i], mac);
-               os_free(buf);
+               bin_clear_free(buf, len[i]);
                return ret;
        }
 

diff --git a/src/crypto/crypto_openssl.c b/src/crypto/crypto_openssl.c
index 69fcf9b..adb42a4 100644 (file)
--- a/src/crypto/crypto_openssl.c
+++ b/src/crypto/crypto_openssl.c
@@ -258,7 +258,7 @@ void aes_encrypt_deinit(void *ctx)
                           "in AES encrypt", len);
        }
        EVP_CIPHER_CTX_cleanup(c);
-       os_free(c);
+       bin_clear_free(c, sizeof(*c));
 }
 
 
@@ -309,7 +309,7 @@ void aes_decrypt_deinit(void *ctx)
                           "in AES decrypt", len);
        }
        EVP_CIPHER_CTX_cleanup(c);
-       os_free(ctx);
+       bin_clear_free(c, sizeof(*c));
 }
 
 
@@ -507,8 +507,8 @@ void * dh5_init(struct wpabuf **priv, struct wpabuf **publ)
        return dh;
 
 err:
-       wpabuf_free(pubkey);
-       wpabuf_free(privkey);
+       wpabuf_clear_free(pubkey);
+       wpabuf_clear_free(privkey);
        DH_free(dh);
        return NULL;
 }
@@ -581,7 +581,7 @@ struct wpabuf * dh5_derive_shared(void *ctx, const struct wpabuf *peer_public,
 
 err:
        BN_clear_free(pub_key);
-       wpabuf_free(res);
+       wpabuf_clear_free(res);
        return NULL;
 }
 
@@ -638,7 +638,7 @@ struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
        HMAC_Init_ex(&ctx->ctx, key, key_len, md, NULL);
 #else /* openssl < 0.9.9 */
        if (HMAC_Init_ex(&ctx->ctx, key, key_len, md, NULL) != 1) {
-               os_free(ctx);
+               bin_clear_free(ctx, sizeof(*ctx));
                return NULL;
        }
 #endif /* openssl < 0.9.9 */
@@ -664,7 +664,7 @@ int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
                return -2;
 
        if (mac == NULL || len == NULL) {
-               os_free(ctx);
+               bin_clear_free(ctx, sizeof(*ctx));
                return 0;
        }
 
@@ -676,7 +676,7 @@ int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
        res = HMAC_Final(&ctx->ctx, mac, &mdlen);
 #endif /* openssl < 0.9.9 */
        HMAC_CTX_cleanup(&ctx->ctx);
-       os_free(ctx);
+       bin_clear_free(ctx, sizeof(*ctx));
 
        if (res == 1) {
                *len = mdlen;