Improve register_{cipher,hash,prng}()

Only go once through `X_descriptor[]` when calling `register_X()`

Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>

Author: sjaeckel

src/misc/crypt/crypt_register_cipher.c

@@ -14,29 +14,31 @@
 */
 int register_cipher(const struct ltc_cipher_descriptor *cipher)
 {
-   int x;
+   int x, blank = -1;
 
    LTC_ARGCHK(cipher != NULL);
 
+   if (cipher->name == NULL)
+      return -1;
+
    /* is it already registered? */
    LTC_MUTEX_LOCK(&ltc_cipher_mutex);
    for (x = 0; x < TAB_SIZE; x++) {
        if (cipher_descriptor[x].name != NULL && cipher_descriptor[x].ID == cipher->ID) {
           LTC_MUTEX_UNLOCK(&ltc_cipher_mutex);
           return x;
        }
+       if (cipher_descriptor[x].name == NULL && blank == -1) {
+          blank = x;
+       }
    }
 
    /* find a blank spot */
-   for (x = 0; x < TAB_SIZE; x++) {
-       if (cipher_descriptor[x].name == NULL) {
-          XMEMCPY(&cipher_descriptor[x], cipher, sizeof(struct ltc_cipher_descriptor));
-          LTC_MUTEX_UNLOCK(&ltc_cipher_mutex);
-          return x;
-       }
+   if (blank != -1) {
+       XMEMCPY(&cipher_descriptor[blank], cipher, sizeof(struct ltc_cipher_descriptor));
    }
 
    /* no spot */
    LTC_MUTEX_UNLOCK(&ltc_cipher_mutex);
-   return -1;
+   return blank;
 }

src/misc/crypt/crypt_register_hash.c

@@ -14,29 +14,31 @@
 */
 int register_hash(const struct ltc_hash_descriptor *hash)
 {
-   int x;
+   int x, blank = -1;
 
    LTC_ARGCHK(hash != NULL);
 
+   if (hash->name == NULL)
+      return -1;
+
    /* is it already registered? */
    LTC_MUTEX_LOCK(&ltc_hash_mutex);
    for (x = 0; x < TAB_SIZE; x++) {
        if (XMEMCMP(&hash_descriptor[x], hash, sizeof(struct ltc_hash_descriptor)) == 0) {
           LTC_MUTEX_UNLOCK(&ltc_hash_mutex);
           return x;
        }
+       if (hash_descriptor[x].name == NULL && blank == -1) {
+          blank = x;
+       }
    }
 
-   /* find a blank spot */
-   for (x = 0; x < TAB_SIZE; x++) {
-       if (hash_descriptor[x].name == NULL) {
-          XMEMCPY(&hash_descriptor[x], hash, sizeof(struct ltc_hash_descriptor));
-          LTC_MUTEX_UNLOCK(&ltc_hash_mutex);
-          return x;
-       }
+   /* fill in blank spot */
+   if (blank != -1) {
+       XMEMCPY(&hash_descriptor[blank], hash, sizeof(struct ltc_hash_descriptor));
    }
 
    /* no spot */
    LTC_MUTEX_UNLOCK(&ltc_hash_mutex);
-   return -1;
+   return blank;
 }

src/misc/crypt/crypt_register_prng.c

@@ -14,29 +14,31 @@
 */
 int register_prng(const struct ltc_prng_descriptor *prng)
 {
-   int x;
+   int x, blank = -1;
 
    LTC_ARGCHK(prng != NULL);
 
+   if (prng->name == NULL)
+      return -1;
+
    /* is it already registered? */
    LTC_MUTEX_LOCK(&ltc_prng_mutex);
    for (x = 0; x < TAB_SIZE; x++) {
        if (XMEMCMP(&prng_descriptor[x], prng, sizeof(struct ltc_prng_descriptor)) == 0) {
           LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
           return x;
        }
+       if (prng_descriptor[x].name == NULL && blank == -1) {
+          blank = x;
+       }
    }
 
    /* find a blank spot */
-   for (x = 0; x < TAB_SIZE; x++) {
-       if (prng_descriptor[x].name == NULL) {
-          XMEMCPY(&prng_descriptor[x], prng, sizeof(struct ltc_prng_descriptor));
-          LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
-          return x;
-       }
+   if (blank != -1) {
+       XMEMCPY(&prng_descriptor[blank], prng, sizeof(struct ltc_prng_descriptor));
    }
 
    /* no spot */
    LTC_MUTEX_UNLOCK(&ltc_prng_mutex);
-   return -1;
+   return blank;
 }