Merge pull request #789 from libtom/pr/zero-stat

verify functions always set stat=0 before any other return

Author: sjaeckel

src/encauth/eax/eax_decrypt_verify_memory.c

@@ -40,15 +40,15 @@ int eax_decrypt_verify_memory(int cipher,
    unsigned char *buf;
    unsigned long  buflen;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the tag is good */
    LTC_ARGCHK(stat != NULL);
+   *stat = 0;
+
    LTC_ARGCHK(key  != NULL);
    LTC_ARGCHK(pt   != NULL);
    LTC_ARGCHK(ct   != NULL);
    LTC_ARGCHK(tag  != NULL);
 
-   /* default to zero */
-   *stat = 0;
-
    if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
       return err;
    }

src/encauth/ocb3/ocb3_decrypt_verify_memory.c

@@ -40,9 +40,8 @@ int ocb3_decrypt_verify_memory(int cipher,
    unsigned char *buf;
    unsigned long  buflen;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the tag is good */
    LTC_ARGCHK(stat    != NULL);
-
-   /* default to zero */
    *stat = 0;
 
    /* limit taglen */

src/pk/dsa/dsa_verify_hash.c

@@ -27,14 +27,14 @@ int dsa_verify_hash_raw(         void   *r,          void   *s,
    void          *w, *v, *u1, *u2;
    int           err;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
+   LTC_ARGCHK(stat != NULL);
+   *stat = 0;
+
    LTC_ARGCHK(r    != NULL);
    LTC_ARGCHK(s    != NULL);
-   LTC_ARGCHK(stat != NULL);
    LTC_ARGCHK(key  != NULL);
 
-   /* default to invalid signature */
-   *stat = 0;
-
    /* init our variables */
    if ((err = ltc_mp_init_multi(&w, &v, &u1, &u2, LTC_NULL)) != CRYPT_OK) {
       return err;
@@ -95,8 +95,9 @@ int dsa_verify_hash(const unsigned char *sig,        unsigned long  siglen,
    ltc_asn1_list sig_seq[2];
    unsigned long reallen = 0;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
    LTC_ARGCHK(stat != NULL);
-   *stat = 0; /* must be set before the first return */
+   *stat = 0;
 
    if ((err = ltc_mp_init_multi(&r, &s, LTC_NULL)) != CRYPT_OK) {
       return err;

src/pk/dsa/dsa_verify_key.c

@@ -43,9 +43,10 @@ int dsa_int_validate_pqg(const dsa_key *key, int *stat)
    void *tmp1, *tmp2;
    int  err;
 
-   LTC_ARGCHK(key  != NULL);
+   /* stat is cleared before anything else can return, it stays 0 unless the params are valid */
    LTC_ARGCHK(stat != NULL);
    *stat = 0;
+   LTC_ARGCHK(key  != NULL);
 
    /* check q-order */
    if ( key->qord >= LTC_MDSA_MAX_GROUP || key->qord <= 15 ||
@@ -96,9 +97,10 @@ int dsa_int_validate_primes(const dsa_key *key, int *stat)
 {
    int err, res;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the primes are valid */
+   LTC_ARGCHK(stat != NULL);
    *stat = 0;
    LTC_ARGCHK(key  != NULL);
-   LTC_ARGCHK(stat != NULL);
 
    /* key->q prime? */
    if ((err = ltc_mp_prime_is_prime(key->q, LTC_MILLER_RABIN_REPS, &res)) != CRYPT_OK) {
@@ -132,9 +134,10 @@ int dsa_int_validate_xy(const dsa_key *key, int *stat)
    void *tmp;
    int  err;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the key is valid */
+   LTC_ARGCHK(stat != NULL);
    *stat = 0;
    LTC_ARGCHK(key  != NULL);
-   LTC_ARGCHK(stat != NULL);
 
    /* 1 < y < p-1 */
    if ((err = ltc_mp_init(&tmp)) != CRYPT_OK) {

src/pk/ecc/ecc_verify_hash.c

@@ -46,8 +46,10 @@ int ecc_verify_hash_v2(const unsigned char *sig,
                                        int *stat,
                        const       ecc_key *key)
 {
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
    LTC_ARGCHK(stat != NULL);
    *stat = 0;
+   LTC_ARGCHK(opts != NULL);
    if (opts->type < 0 || opts->type >= LTC_ARRAY_SIZE(s_ecc_verify_hash))
       return CRYPT_PK_INVALID_TYPE;
    if (s_ecc_verify_hash[opts->type] == NULL)

src/pk/ecc/ecc_verify_hash_eth27.c

@@ -27,6 +27,10 @@ int ecc_verify_hash_eth27(const unsigned char *sig,  unsigned long siglen,
    void *r, *s;
    int err;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
+   LTC_ARGCHK(stat != NULL);
+   *stat = 0;
+
    LTC_ARGCHK(sig != NULL);
    LTC_ARGCHK(key != NULL);
 

src/pk/ecc/ecc_verify_hash_internal.c

@@ -17,15 +17,15 @@ int ecc_verify_hash_internal(void *r, void *s,
    unsigned long pbits, pbytes, i, shift_right;
    unsigned char ch, buf[MAXBLOCKSIZE];
 
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
+   LTC_ARGCHK(stat != NULL);
+   *stat = 0;
+
    LTC_ARGCHK(r    != NULL);
    LTC_ARGCHK(s    != NULL);
    LTC_ARGCHK(hash != NULL);
-   LTC_ARGCHK(stat != NULL);
    LTC_ARGCHK(key  != NULL);
 
-   /* default to invalid signature */
-   *stat = 0;
-
    /* allocate ints */
    if ((err = ltc_mp_init_multi(&v, &w, &u1, &u2, &e, &a_plus3, LTC_NULL)) != CRYPT_OK) {
       return err;

src/pk/ecc/ecc_verify_hash_rfc5656.c

@@ -31,6 +31,10 @@ int ecc_verify_hash_rfc5656(const unsigned char *sig,  unsigned long siglen,
    unsigned long name2len = sizeof(name2);
    unsigned long slen = siglen;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
+   LTC_ARGCHK(stat != NULL);
+   *stat = 0;
+
    LTC_ARGCHK(sig != NULL);
    LTC_ARGCHK(key != NULL);
 

src/pk/ecc/ecc_verify_hash_rfc7518.c

@@ -18,6 +18,10 @@ int ecc_verify_hash_rfc7518_internal(const unsigned char *sig,  unsigned long si
    int err;
    unsigned long i;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
+   LTC_ARGCHK(stat != NULL);
+   *stat = 0;
+
    LTC_ARGCHK(sig != NULL);
    LTC_ARGCHK(key != NULL);
 

src/pk/ecc/ecc_verify_hash_x962.c

@@ -17,6 +17,10 @@ int ecc_verify_hash_x962(const unsigned char *sig,  unsigned long siglen,
    void *r, *s;
    int err;
 
+   /* stat is cleared before anything else can return, it stays 0 unless the signature is good */
+   LTC_ARGCHK(stat != NULL);
+   *stat = 0;
+
    LTC_ARGCHK(sig != NULL);
 
    if ((err = ltc_mp_init_multi(&r, &s, NULL)) != CRYPT_OK) return err;