+ _crypto_pwhash_scryptsalsa208sha256_str_needs_rehash()

dist-build/emscripten-symbols.def

@@ -332,6 +332,7 @@ _crypto_pwhash_scryptsalsa208sha256_passwd_max 0 1
 _crypto_pwhash_scryptsalsa208sha256_passwd_min 0 1
 _crypto_pwhash_scryptsalsa208sha256_saltbytes 0 1
 _crypto_pwhash_scryptsalsa208sha256_str 0 1
+_crypto_pwhash_scryptsalsa208sha256_str_needs_rehash 0 1
 _crypto_pwhash_scryptsalsa208sha256_str_verify 0 1
 _crypto_pwhash_scryptsalsa208sha256_strbytes 0 1
 _crypto_pwhash_scryptsalsa208sha256_strprefix 0 1

src/libsodium/crypto_pwhash/scryptsalsa208sha256/crypto_scrypt-common.c

@@ -105,6 +105,34 @@ decode64_uint32(uint32_t *dst, uint32_t dstbits, const uint8_t *src)
     return src;
 }
 
+const uint8_t *
+escrypt_parse_setting(const uint8_t *setting,
+                      uint32_t *N_log2_p, uint32_t *r_p, uint32_t *p_p)
+{
+    const uint8_t *src;
+
+    if (setting[0] != '$' || setting[1] != '7' || setting[2] != '$') {
+        return NULL;
+    }
+    src = setting + 3;
+
+    if (decode64_one(N_log2_p, *src)) {
+        return NULL;
+    }
+    src++;
+
+    src = decode64_uint32(r_p, 30, src);
+    if (!src) {
+        return NULL;
+    }
+
+    src = decode64_uint32(p_p, 30, src);
+    if (!src) {
+        return NULL;
+    }
+    return src;
+}
+
 uint8_t *
 escrypt_r(escrypt_local_t *local, const uint8_t *passwd, size_t passwdlen,
           const uint8_t *setting, uint8_t *buf, size_t buflen)
@@ -122,25 +150,11 @@ escrypt_r(escrypt_local_t *local, const uint8_t *passwd, size_t passwdlen,
     uint32_t       r;
     uint32_t       p;
 
-    if (setting[0] != '$' || setting[1] != '7' || setting[2] != '$') {
+    src = escrypt_parse_setting(setting, &N_log2, &r, &p);
+    if (!src) {
         return NULL;
     }
-    src = setting + 3;
-
-    if (decode64_one(&N_log2, *src)) {
-        return NULL;
-    }
-    src++;
     N = (uint64_t) 1 << N_log2;
-
-    src = decode64_uint32(&r, 30, src);
-    if (!src) {
-        return NULL;
-    }
-    src = decode64_uint32(&p, 30, src);
-    if (!src) {
-        return NULL;
-    }
     prefixlen = src - setting;
 
     salt = src;

src/libsodium/crypto_pwhash/scryptsalsa208sha256/crypto_scrypt.h

@@ -91,4 +91,8 @@ extern uint8_t *escrypt_gensalt_r(uint32_t __N_log2, uint32_t __r, uint32_t __p,
                                   const uint8_t *__src, size_t __srclen,
                                   uint8_t *__buf, size_t __buflen);
 
+extern const uint8_t *escrypt_parse_setting(const uint8_t *setting,
+                                            uint32_t *N_log2_p, uint32_t *r_p,
+                                            uint32_t *p_p);
+
 #endif /* !_CRYPTO_SCRYPT_H_ */

src/libsodium/crypto_pwhash/scryptsalsa208sha256/pwhash_scryptsalsa208sha256.c

@@ -254,3 +254,32 @@ crypto_pwhash_scryptsalsa208sha256_str_verify(
 
     return ret;
 }
+
+int
+crypto_pwhash_scryptsalsa208sha256_str_needs_rehash(
+    const char str[crypto_pwhash_scryptsalsa208sha256_STRBYTES],
+    unsigned long long opslimit, size_t memlimit)
+{
+    uint32_t N_log2, N_log2_;
+    uint32_t p, p_;
+    uint32_t r, r_;
+
+    if (pickparams(opslimit, memlimit, &N_log2, &p, &r) != 0) {
+        errno = EINVAL;
+        return -1;
+    }
+    if (memchr(str, 0, crypto_pwhash_scryptsalsa208sha256_STRBYTES) !=
+        &str[crypto_pwhash_scryptsalsa208sha256_STRBYTES - 1U]) {
+        errno = EINVAL;
+        return -1;
+    }
+    if (escrypt_parse_setting((const uint8_t *) str,
+                              &N_log2_, &r_, &p_) == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    if (N_log2 != N_log2_ || r != r_ || p != p_) {
+        return 1;
+    }
+    return 0;
+}

src/libsodium/include/sodium/crypto_pwhash_scryptsalsa208sha256.h

@@ -107,6 +107,12 @@ int crypto_pwhash_scryptsalsa208sha256_ll(const uint8_t * passwd, size_t passwdl
                                           uint8_t * buf, size_t buflen)
             __attribute__ ((warn_unused_result));
 
+SODIUM_EXPORT
+int crypto_pwhash_scryptsalsa208sha256_str_needs_rehash(const char str[crypto_pwhash_scryptsalsa208sha256_STRBYTES],
+                                                        unsigned long long opslimit,
+                                                        size_t memlimit)
+            __attribute__ ((warn_unused_result));
+
 #ifdef __cplusplus
 }
 #endif