[FIX] Improve code security by prevent buffer overflow.

1 files changed, 170 insertions, 77 deletions

diff --git a/src/inexact.c b/src/inexact.c
index 16d6175..2f51d30 100644
--- a/src/inexact.c
+++ b/src/inexact.c
@@ -38,12 +38,15 @@ int generate_keys(const char *seckey_filename, const char *pubkey_filename,
     unsigned char *publickey_b64 = NULL;
     unsigned char *privatekey_b64t = NULL;
     unsigned char *publickey_b64t = NULL;
-    unsigned char salt[32] = {0};
-    unsigned char privatekey_buffer[64] = {0};
+    unsigned char *salt = NULL;
+    const size_t salt_len = 32;
+    unsigned char *privatekey_buffer = NULL;
+    const size_t privatekey_buffer_len = 64;
 
-    char password[256] = {0};
+    char *password = NULL;
+    const size_t password_maxlen = 256;
     char *password_out = NULL;
-    char password_verif[256] = {0};
+    char *password_verif = NULL;
     char *password_verif_out = NULL;
     size_t password_len = 0;
     size_t password_verif_len = 0;
@@ -67,6 +70,17 @@ int generate_keys(const char *seckey_filename, const char *pubkey_filename,
     curve25519_key privatekey;
     curve25519_key publickey;
 
+    salt = malloc(salt_len);
+    privatekey_buffer = malloc(privatekey_buffer_len);
+    password = malloc(password_maxlen);
+    password_verif = malloc(password_maxlen);
+
+    if (salt == NULL || privatekey_buffer == NULL || password == NULL ||
+        password_verif == NULL) {
+        printf("Malloc failed\n");
+        goto exit;
+    }
+
     /* Secret (or private) key */
 
     if (no_password) {
@@ -92,27 +106,27 @@ int generate_keys(const char *seckey_filename, const char *pubkey_filename,
             printf("Chacha20 allocation failed: %d\n", ret);
             goto exit;
         }
-        if (drng_chacha20_get(drng, salt, sizeof(salt))) {
+        if (drng_chacha20_get(drng, salt, salt_len)) {
             printf("Getting random numbers failed\n");
             goto exit;
         }
 
         password_out =
-            readpassphrase("Password : ", password, sizeof(password), 0);
+            readpassphrase("Password : ", password, password_maxlen, 0);
         if (password_out != password) {
             printf("password input failed.\n");
             goto exit;
         }
-        password_len = strlen(password);
+        password_len = strnlen(password, password_maxlen);
 
         password_verif_out =
             readpassphrase("Verifying, please re-enter : ", password_verif,
-                           sizeof(password_verif), 0);
+                           password_maxlen, 0);
         if (password_verif_out != password_verif) {
             printf("password input failed.\n");
             goto exit;
         }
-        password_verif_len = strlen(password_verif);
+        password_verif_len = strnlen(password_verif, password_maxlen);
 
         if (password_len != password_verif_len) {
             printf("Mismatch.\n");
@@ -125,20 +139,19 @@ int generate_keys(const char *seckey_filename, const char *pubkey_filename,
         }
 
         int a2res = argon2id_hash_raw(t_cost, m_cost, parallelism, password,
-                                      password_len, salt, sizeof(salt),
-                                      privatekey, sizeof(curve25519_key));
+                                      password_len, salt, salt_len, privatekey,
+                                      sizeof(curve25519_key));
         if (a2res != ARGON2_OK) {
             printf("argon2 failed.");
             goto exit;
         }
 
         curve25519_donna_basepoint(publickey, privatekey);
-        memcpy(privatekey_buffer, salt, sizeof(salt));
-        memcpy(privatekey_buffer + sizeof(salt), publickey,
-               sizeof(curve25519_key));
+        memcpy(privatekey_buffer, salt, salt_len);
+        memcpy(privatekey_buffer + salt_len, publickey, sizeof(curve25519_key));
     }
 
-    privatekey_b64 = base64_encode(privatekey_buffer, sizeof(privatekey_buffer),
+    privatekey_b64 = base64_encode(privatekey_buffer, privatekey_buffer_len,
                                    &private_base64_len);
     if (privatekey_b64 == NULL) {
         printf("base64 encoding failed.\n");
@@ -219,15 +232,19 @@ exit:
     memset(publickey_b64, 0, public_base64_len);
     memset(publickey_b64t, 0, public_b64t_len);
     memset(publickey, 0, sizeof(curve25519_key));
-    memset(salt, 0, sizeof(salt));
-    memset(privatekey_buffer, 0, sizeof(privatekey_buffer));
-    memset(password, 0, sizeof(password));
-    memset(password_verif, 0, sizeof(password_verif));
+    memset(salt, 0, salt_len);
+    memset(privatekey_buffer, 0, privatekey_buffer_len);
+    memset(password, 0, password_maxlen);
+    memset(password_verif, 0, password_maxlen);
 
     free(privatekey_b64);
     free(publickey_b64);
     free(privatekey_b64t);
     free(publickey_b64t);
+    free(salt);
+    free(privatekey_buffer);
+    free(password);
+    free(password_verif);
 
     if (fs != NULL) {
         fclose(fs);
@@ -253,8 +270,10 @@ int get_seckey(const char *keyfile, unsigned char *skey, unsigned char *pkey) {
 
     FILE *fs = NULL;
 
-    unsigned char salt[32] = {0};
-    char password[256] = {0};
+    unsigned char *salt = NULL;
+    const size_t salt_len = 32;
+    char *password = NULL;
+    const size_t password_maxlen = 256;
     char *password_out = NULL;
     curve25519_key pubkey;
     curve25519_key pubkey_from_secret;
@@ -264,8 +283,21 @@ int get_seckey(const char *keyfile, unsigned char *skey, unsigned char *pkey) {
     const uint32_t m_cost = (1 << 12);
     const uint32_t parallelism = 1;
 
+    /* max_size = base64(sizeof(curve25519_key)) = 64 * 4 / 3 + 1 -> 86 */
+    const size_t file_data_len = 87;
+    unsigned char *file_data = NULL;
+
     int exitcode = 1;
 
+    file_data = malloc(file_data_len);
+    salt = malloc(salt_len);
+    password = malloc(password_maxlen);
+
+    if (salt == NULL || password == NULL || file_data == NULL) {
+        printf("Malloc failed\n");
+        goto exit;
+    }
+
     fs = fopen(keyfile, "rb");
     if (fs == NULL) {
         printf("key file opening failed: %s.\n", strerror(errno));
@@ -291,15 +323,12 @@ int get_seckey(const char *keyfile, unsigned char *skey, unsigned char *pkey) {
         goto exit;
     }
 
-    /* max_size = base64(sizeof(curve25519_key)) = 64 * 4 / 3 + 1 -> 86 */
-    unsigned char file_data[87] = {0};
-
-    if (sz > sizeof(file_data)) {
+    if (sz > file_data_len) {
         printf("Bad key size\n");
         goto exit;
     }
 
-    size_t readed = fread(&file_data, 1, sz, fs);
+    size_t readed = fread(file_data, 1, sz, fs);
     if (readed != sz) {
         printf("read file '%s' failed: %s.\n", keyfile, strerror(errno));
         goto exit;
@@ -331,17 +360,17 @@ int get_seckey(const char *keyfile, unsigned char *skey, unsigned char *pkey) {
     int password_protected_flag =
         (memcmp(pubkey, pubkey_from_secret, sizeof(curve25519_key)) != 0);
     if (password_protected_flag) {
-        memcpy(salt, base64_decoded, sizeof(salt));
+        memcpy(salt, base64_decoded, salt_len);
         password_out =
-            readpassphrase("Password : ", password, sizeof(password), 0);
+            readpassphrase("Password : ", password, password_maxlen, 0);
         if (password_out != password) {
             printf("password input failed.\n");
             goto exit;
         }
-        password_len = strlen(password);
+        password_len = strnlen(password, password_maxlen);
 
         int a2res = argon2id_hash_raw(t_cost, m_cost, parallelism, password,
-                                      password_len, salt, sizeof(salt), seckey,
+                                      password_len, salt, salt_len, seckey,
                                       sizeof(curve25519_key));
         if (a2res != ARGON2_OK) {
             printf("argon2 failed.");
@@ -361,11 +390,11 @@ int get_seckey(const char *keyfile, unsigned char *skey, unsigned char *pkey) {
     exitcode = 0;
 
 exit:
-    memset(file_data, 0, sizeof(file_data));
+    memset(file_data, 0, file_data_len);
     memset(base64_decoded, 0, base64_decoded_len);
     memset(b64t_decoded, 0, b64t_decoded_len);
-    memset(salt, 0, sizeof(salt));
-    memset(password, 0, sizeof(password));
+    memset(salt, 0, salt_len);
+    memset(password, 0, password_maxlen);
     memset(seckey, 0, sizeof(curve25519_key));
     memset(pubkey, 0, sizeof(curve25519_key));
     memset(pubkey_from_secret, 0, sizeof(curve25519_key));
@@ -376,6 +405,9 @@ exit:
 
     free(base64_decoded);
     free(b64t_decoded);
+    free(salt);
+    free(password);
+    free(file_data);
 
     return exitcode;
 }
@@ -395,6 +427,15 @@ int get_pubkey(const char *keyfile, unsigned char *pkey) {
 
     curve25519_key pubkey;
 
+    /* max_size = base64(sizeof(curve25519_key)) = 32 * 4 / 3 + 1 -> 44 */
+    const size_t file_data_len = 45;
+    unsigned char *file_data = malloc(file_data_len);
+
+    if (file_data == NULL) {
+        printf("Malloc failed\n");
+        goto exit;
+    }
+
     int exitcode = 1;
 
     fs = fopen(keyfile, "rb");
@@ -422,15 +463,12 @@ int get_pubkey(const char *keyfile, unsigned char *pkey) {
         goto exit;
     }
 
-    /* max_size = base64(sizeof(curve25519_key)) = 32 * 4 / 3 + 1 -> 44 */
-    unsigned char file_data[44] = {0};
-
-    if (sz > sizeof(file_data)) {
+    if (sz > file_data_len) {
         printf("Bad key size\n");
         goto exit;
     }
 
-    size_t readed = fread(&file_data, 1, sz, fs);
+    size_t readed = fread(file_data, 1, sz, fs);
     if (readed != sz) {
         printf("read file '%s' failed: %s.\n", keyfile, strerror(errno));
         goto exit;
@@ -459,7 +497,7 @@ int get_pubkey(const char *keyfile, unsigned char *pkey) {
     exitcode = 0;
 
 exit:
-    memset(file_data, 0, sizeof(file_data));
+    memset(file_data, 0, file_data_len);
     memset(b64t_decoded, 0, b64t_decoded_len);
     memset(base64_decoded, 0, base64_decoded_len);
     memset(pubkey, 0, sizeof(curve25519_key));
@@ -470,6 +508,7 @@ exit:
 
     free(b64t_decoded);
     free(base64_decoded);
+    free(file_data);
 
     return exitcode;
 }
@@ -506,7 +545,7 @@ unsigned char *encrypt_data(const unsigned char *seckey,
     size_t encrypted_len = 0;
 
     const size_t shared_secret_len = 32;
-    unsigned char shared_secret[32] = {0};
+    unsigned char *shared_secret = NULL;
 
     const size_t nonce1_len = 32;
     const size_t tag0_len = 4;
@@ -516,29 +555,35 @@ unsigned char *encrypt_data(const unsigned char *seckey,
     const size_t nonce0_len = 32;
     const size_t header0_len = 4;
     const size_t encrypted_len_expected = data_len + tag1_len;
+    const size_t salt_len = 32;
 
     const uint8_t *key1 = 0;
     const uint8_t *nonce1 = 0;
-    unsigned char params[5] = {0};
-    unsigned char params_encrypted[9] = {0};
+    unsigned char *params = NULL;
+    unsigned char *params_encrypted = NULL;
     const uint8_t *key0 = 0;
     const uint8_t *nonce0 = 0;
-    unsigned char header0[4] = {0};
+    unsigned char *header0 = NULL;
 
     struct chacha20_drng *drng = NULL;
 
     *out_encrypted_len = 0;
 
-    // generate shared secret from DH X25519
-    curve25519_donna(shared_secret, seckey, pubkey);
+    shared_secret = malloc(shared_secret_len);
+    params = malloc(params_len);
+    params_encrypted = malloc(params_encrypted_len);
+    header0 = malloc(header0_len);
+    rand = malloc(rand_len);  // generate part 1 random data
 
-    // generate part 1 random data
-    rand = malloc(rand_len);
-    if (rand == NULL) {
+    if (shared_secret == NULL || params == NULL || params_encrypted == NULL ||
+        header0 == NULL || rand == NULL) {
         printf("malloc failed.\n");
         goto exit;
     }
 
+    // generate shared secret from DH X25519
+    curve25519_donna(shared_secret, seckey, pubkey);
+
     int ret = drng_chacha20_init(&drng);
     if (ret) {
         printf("Chacha20 allocation failed: %d\n", ret);
@@ -643,10 +688,13 @@ unsigned char *encrypt_data(const unsigned char *seckey,
     }
 
     if (salt) {
-        memcpy(encrypted, salt, 32);
-        memcpy(32 + encrypted, pubkey, 32);
-        memcpy(64 + encrypted, params_encrypted, params_encrypted_len);
-        memcpy(64 + encrypted + params_encrypted_len, part1, part1_len);
+        memcpy(encrypted, salt, salt_len);
+        memcpy(salt_len + encrypted, pubkey, sizeof(curve25519_key));
+        memcpy(salt_len + sizeof(curve25519_key) + encrypted, params_encrypted,
+               params_encrypted_len);
+        memcpy(salt_len + sizeof(curve25519_key) + encrypted +
+                   params_encrypted_len,
+               part1, part1_len);
     } else {
         memcpy(encrypted, params_encrypted, params_encrypted_len);
         memcpy(encrypted + params_encrypted_len, part1, part1_len);
@@ -699,6 +747,10 @@ exit:
     free(encrypted1);
     free(part1);
     free(encrypted);
+    free(header0);
+    free(shared_secret);
+    free(params);
+    free(params_encrypted);
 
     return out;
 }
@@ -711,15 +763,25 @@ int get_symmetrickeys(unsigned char *salt_out, unsigned char *seckey_out,
     const uint32_t m_cost = (1 << 12);
     const uint32_t parallelism = 1;
 
-    char password[256] = {0};
+    char *password = NULL;
     char *password_out = NULL;
-    char password_verif[256] = {0};
+    char *password_verif = NULL;
     char *password_verif_out = NULL;
     size_t password_len = 0;
     size_t password_verif_len = 0;
+    const size_t password_maxlen = 256;
+    const size_t salt_len = 32;
 
     int exitcode = 1;
 
+    password = malloc(password_maxlen);
+    password_verif = malloc(password_maxlen);
+
+    if (password == NULL || password_verif == NULL) {
+        printf("Malloc failed\n");
+        goto exit;
+    }
+
     int ret = drng_chacha20_init(&drng);
     if (ret) {
         printf("Chacha20 allocation failed: %d\n", ret);
@@ -730,21 +792,20 @@ int get_symmetrickeys(unsigned char *salt_out, unsigned char *seckey_out,
         goto exit;
     }
 
-    password_out = readpassphrase("Password : ", password, sizeof(password), 0);
+    password_out = readpassphrase("Password : ", password, password_maxlen, 0);
     if (password_out != password) {
         printf("password input failed.\n");
         goto exit;
     }
-    password_len = strlen(password);
+    password_len = strnlen(password, password_maxlen);
 
-    password_verif_out =
-        readpassphrase("Verifying, please re-enter : ", password_verif,
-                       sizeof(password_verif), 0);
+    password_verif_out = readpassphrase(
+        "Verifying, please re-enter : ", password_verif, password_maxlen, 0);
     if (password_verif_out != password_verif) {
         printf("password input failed.\n");
         goto exit;
     }
-    password_verif_len = strlen(password_verif);
+    password_verif_len = strnlen(password_verif, password_maxlen);
 
     if (password_len != password_verif_len) {
         printf("Mismatch.\n");
@@ -758,7 +819,7 @@ int get_symmetrickeys(unsigned char *salt_out, unsigned char *seckey_out,
 
     int a2res =
         argon2id_hash_raw(t_cost, m_cost, parallelism, password, password_len,
-                          salt_out, 32, seckey_out, sizeof(curve25519_key));
+                          salt_out, salt_len, seckey_out, sizeof(curve25519_key));
     if (a2res != ARGON2_OK) {
         printf("argon2 failed.");
         goto exit;
@@ -770,8 +831,10 @@ int get_symmetrickeys(unsigned char *salt_out, unsigned char *seckey_out,
 
 exit:
     drng_chacha20_destroy(drng);
-    memset(password, 0, sizeof(password));
-    memset(password_verif, 0, sizeof(password_verif));
+    memset(password, 0, password_maxlen);
+    memset(password_verif, 0, password_maxlen);
+    free(password);
+    free(password_verif);
 
     return exitcode;
 }
@@ -783,7 +846,7 @@ int check_get_symmetrickeys(const unsigned char *data, const size_t data_len,
     const uint32_t m_cost = (1 << 12);
     const uint32_t parallelism = 1;
 
-    char password[256] = {0};
+    char *password = NULL;
     char *password_out = NULL;
     size_t password_len = 0;
 
@@ -792,11 +855,21 @@ int check_get_symmetrickeys(const unsigned char *data, const size_t data_len,
     size_t data_b64t_decoded_len = 0;
     size_t encrypted_len = 0;
 
-    unsigned char salt[32] = {0};
+    unsigned char *salt = NULL;
+    const size_t salt_len = 32;
+    const size_t password_maxlen = 256;
 
     curve25519_key pubkey_from_secret;
     int exitcode = 1;
 
+    password = malloc(password_maxlen);
+    salt = malloc(salt_len);
+
+    if (password == NULL || salt == NULL) {
+        printf("Malloc failed\n");
+        goto exit;
+    }
+
     data_b64t_decoded = b64t_decode(data, data_len, &data_b64t_decoded_len);
 
     encrypted =
@@ -806,19 +879,19 @@ int check_get_symmetrickeys(const unsigned char *data, const size_t data_len,
         goto exit;
     }
 
-    memcpy(salt, encrypted, 32);
-    memcpy(pubkey_from_secret, encrypted + 32, 32);
+    memcpy(salt, encrypted, salt_len);
+    memcpy(pubkey_from_secret, encrypted + 32, sizeof(curve25519_key));
 
-    password_out = readpassphrase("Password : ", password, sizeof(password), 0);
+    password_out = readpassphrase("Password : ", password, password_maxlen, 0);
     if (password_out != password) {
         printf("password input failed.\n");
         goto exit;
     }
-    password_len = strlen(password);
+    password_len = strnlen(password, password_maxlen);
 
     int a2res =
         argon2id_hash_raw(t_cost, m_cost, parallelism, password, password_len,
-                          salt, 32, seckey_out, sizeof(curve25519_key));
+                          salt, salt_len, seckey_out, sizeof(curve25519_key));
     if (a2res != ARGON2_OK) {
         printf("argon2 failed.");
         goto exit;
@@ -828,7 +901,7 @@ int check_get_symmetrickeys(const unsigned char *data, const size_t data_len,
     if (memcmp(pubkey_out, pubkey_from_secret, sizeof(curve25519_key)) != 0) {
         printf("Wrong password\n");
         memset(seckey_out, 0, sizeof(curve25519_key));
-        memset(salt, 0, 32);
+        memset(salt, 0, salt_len);
         memset(pubkey_out, 0, sizeof(curve25519_key));
         goto exit;
     }
@@ -836,12 +909,15 @@ int check_get_symmetrickeys(const unsigned char *data, const size_t data_len,
     exitcode = 0;
 
 exit:
-    memset(password, 0, sizeof(password));
+    memset(password, 0, password_maxlen);
     memset(encrypted, 0, encrypted_len);
     memset(data_b64t_decoded, 0, data_b64t_decoded_len);
+    memset(salt, 0, salt_len);
 
     free(encrypted);
     free(data_b64t_decoded);
+    free(password);
+    free(salt);
 
     return exitcode;
 }
@@ -861,8 +937,8 @@ unsigned char *decrypt_data(const unsigned char *seckey,
     unsigned char *message = NULL;
     unsigned char *encrypted1 = NULL;
 
-    size_t shared_secret_len = 32;
-    unsigned char shared_secret[32] = {0};
+    const size_t shared_secret_len = 32;
+    unsigned char *shared_secret = NULL;
 
     size_t encrypted_len = 0;
     size_t data_b64t_decoded_len = 0;
@@ -884,15 +960,27 @@ unsigned char *decrypt_data(const unsigned char *seckey,
 
     const uint8_t *nonce0 = 0;
     const size_t header0_len = 4;
-    unsigned char header0[4] = {0};
+    unsigned char *header0 = NULL;
     const uint8_t *key0 = 0;
-    unsigned char encrypted0[9] = {0};
+    unsigned char *encrypted0 = NULL;
+    const size_t encrypted0_len = 9;
     const size_t params_len = 5;
-    unsigned char params[5];
+    unsigned char *params = NULL;
     size_t norx_params_len = 0;
     const uint8_t *nonce1 = 0;
     const uint8_t *key1 = 0;
 
+    shared_secret = malloc(shared_secret_len);
+    encrypted0 = malloc(encrypted0_len);
+    params = malloc(params_len);
+    header0 = malloc(header0_len);
+
+    if (shared_secret == NULL || encrypted0 == NULL || params == NULL ||
+        header0 == NULL) {
+        printf("Malloc failed\n");
+        goto exit;
+    }
+
     // shared secret DH X25519
     curve25519_donna(shared_secret, seckey, pubkey);
 
@@ -1031,6 +1119,11 @@ exit:
     memset(&nc0, 0, sizeof(sha3_context));
     memset(&nc1, 0, sizeof(sha3_context));
 
+    free(shared_secret);
+    free(encrypted0);
+    free(params);
+    free(header0);
+
     free(data_b64t_decoded);
     if (symmetric_flag)
         free(encrypted - 64);