s4:heimdal: import lorikeet-heimdal-202201172009 (commit 5a0b45cd723628b3690ea848548b...

[samba.git] / source4 / heimdal / lib / krb5 / n-fold.c

diff --git a/source4/heimdal/lib/krb5/n-fold.c b/source4/heimdal/lib/krb5/n-fold.c
index 2e6092c5ca80bb1e9c99f44fe7f53585421a4a8e..ba3150d423b85a0f57a65873e2f5203f0ce56a25 100644 (file)
--- a/source4/heimdal/lib/krb5/n-fold.c
+++ b/source4/heimdal/lib/krb5/n-fold.c
@@ -32,68 +32,79 @@
 
 #include "krb5_locl.h"
 
-static krb5_error_code
-rr13(unsigned char *buf, size_t len)
+static void
+rr13(uint8_t *dst1, uint8_t *dst2, uint8_t *src, size_t len)
 {
-    unsigned char *tmp;
     int bytes = (len + 7) / 8;
     int i;
-    if(len == 0)
-       return 0;
-    {
-       const int bits = 13 % len;
-       const int lbit = len % 8;
-
-       tmp = malloc(bytes);
-       if (tmp == NULL)
-           return ENOMEM;
-       memcpy(tmp, buf, bytes);
-       if(lbit) {
-           /* pad final byte with inital bits */
-           tmp[bytes - 1] &= 0xff << (8 - lbit);
-           for(i = lbit; i < 8; i += len)
-               tmp[bytes - 1] |= buf[0] >> i;
-       }
-       for(i = 0; i < bytes; i++) {
-           int bb;
-           int b1, s1, b2, s2;
-           /* calculate first bit position of this byte */
-           bb = 8 * i - bits;
-           while(bb < 0)
-               bb += len;
-           /* byte offset and shift count */
-           b1 = bb / 8;
-           s1 = bb % 8;
-
-           if(bb + 8 > bytes * 8)
-               /* watch for wraparound */
-               s2 = (len + 8 - s1) % 8;
-           else
-               s2 = 8 - s1;
-           b2 = (b1 + 1) % bytes;
-           buf[i] = (tmp[b1] << s1) | (tmp[b2] >> s2);
-       }
-       free(tmp);
+    const int bits = 13 % len;
+
+    for (i = 0; i < bytes; i++) {
+       int bb;
+       int b1, s1, b2, s2;
+       /* calculate first bit position of this byte */
+       bb = 8 * i - bits;
+       while(bb < 0)
+           bb += len;
+       /* byte offset and shift count */
+       b1 = bb / 8;
+       s1 = bb % 8;
+
+       if (bb + 8 > bytes * 8)
+           /* watch for wraparound */
+           s2 = (len + 8 - s1) % 8;
+       else
+           s2 = 8 - s1;
+       b2 = (b1 + 1) % bytes;
+       dst1[i] = (src[b1] << s1) | (src[b2] >> s2);
+       dst2[i] = dst1[i];
     }
-    return 0;
+
+    return;
 }
 
-/* Add `b' to `a', both being one's complement numbers. */
+/*
+ * Add `b' to `a', both being one's complement numbers.
+ * This function assumes that inputs *a, *b are aligned
+ * to 4 bytes.
+ */
 static void
-add1(unsigned char *a, unsigned char *b, size_t len)
+add1(uint8_t *a, uint8_t *b, size_t len)
 {
     int i;
     int carry = 0;
-    for(i = len - 1; i >= 0; i--){
-       int x = a[i] + b[i] + carry;
+    uint32_t x;
+    uint32_t left, right;
+
+    for (i = len - 1; (i+1) % 4; i--) {
+       x = a[i] + b[i] + carry;
        carry = x > 0xff;
        a[i] = x & 0xff;
     }
-    for(i = len - 1; carry && i >= 0; i--){
-       int x = a[i] + carry;
+
+    for (i = len / 4 - 1; i >= 0; i--) {
+       left = ntohl(((uint32_t *)a)[i]);
+       right = ntohl(((uint32_t *)b)[i]);
+       x = left + right + carry;
+       carry = x < left || x < right;
+       ((uint32_t *)a)[i]  = x;
+    }
+
+    for (i = len - 1; (i+1) % 4; i--) {
+       x = a[i] + carry;
        carry = x > 0xff;
        a[i] = x & 0xff;
     }
+
+    for (i = len / 4 - 1; carry && i >= 0; i--) {
+        left = ((uint32_t *)a)[i];
+        x = left + carry;
+        carry = x < left;
+        ((uint32_t *)a)[i] = x;
+    }
+
+    for (i = len / 4 - 1; i >=0; i--)
+        ((uint32_t *)a)[i] = htonl(((uint32_t *)a)[i]);
 }
 
 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
@@ -101,25 +112,25 @@ _krb5_n_fold(const void *str, size_t len, void *key, size_t size)
 {
     /* if len < size we need at most N * len bytes, ie < 2 * size;
        if len > size we need at most 2 * len */
-    krb5_error_code ret = 0;
     size_t maxlen = 2 * max(size, len);
     size_t l = 0;
-    unsigned char *tmp = malloc(maxlen);
-    unsigned char *buf = malloc(len);
+    uint8_t *tmp;
+    uint8_t *tmpbuf;
+    uint8_t *buf1;
+    uint8_t *buf2;
 
-    if (tmp == NULL || buf == NULL) {
-        ret = ENOMEM;
-       goto out;
-    }
+    tmp = malloc(maxlen + 2 * len);
+    if (tmp == NULL)
+        return ENOMEM;
+
+    buf1 = tmp + maxlen;
+    buf2 = tmp + maxlen + len;
 
-    memcpy(buf, str, len);
     memset(key, 0, size);
+    memcpy(buf1, str, len);
+    memcpy(tmp, buf1, len);
     do {
-       memcpy(tmp + l, buf, len);
        l += len;
-       ret = rr13(buf, len * 8);
-       if (ret)
-           goto out;
        while(l >= size) {
            add1(key, tmp, size);
            l -= size;
@@ -127,15 +138,13 @@ _krb5_n_fold(const void *str, size_t len, void *key, size_t size)
                break;
            memmove(tmp, tmp + size, l);
        }
+       rr13(tmp + l, buf2, buf1, len * 8);
+       tmpbuf = buf1;
+       buf1 = buf2;
+       buf2 = tmpbuf;
     } while(l != 0);
-out:
-    if (buf) {
-        memset(buf, 0, len);
-       free(buf);
-    }
-    if (tmp) {
-        memset(tmp, 0, maxlen);
-       free(tmp);
-    }
-    return ret;
+
+    memset(tmp, 0, maxlen + 2 * len);
+    free(tmp);
+    return 0;
 }