for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
mdfour_update(&m, (uchar *)(buf1+i), CSUM_CHUNK);
}
- if (len - i > 0) {
+ /*
+ * Prior to version 27 an incorrect MD4 checksum was computed
+ * by failing to call mdfour_tail() for block sizes that
+ * are multiples of 64. This is fixed by calling mdfour_update()
+ * even when there are no more bytes.
+ */
+ if (len - i > 0 || remote_version >= 27) {
mdfour_update(&m, (uchar *)(buf1+i), (len-i));
}
mdfour_update(&m, (uchar *)tmpchunk, CSUM_CHUNK);
}
+ /*
+ * Prior to version 27 an incorrect MD4 checksum was computed
+ * by failing to call mdfour_tail() for block sizes that
+ * are multiples of 64. This is fixed by calling mdfour_update()
+ * even when there are no more bytes.
+ */
if (len - i > 0) {
memcpy(tmpchunk, map_ptr(buf,i,len-i), len-i);
+ }
+ if (len - i > 0 || remote_version >= 27) {
mdfour_update(&m, (uchar *)tmpchunk, (len-i));
}
md->C = 0x98badcfe;
md->D = 0x10325476;
md->totalN = 0;
+ md->totalN2 = 0;
}
-static void mdfour_tail(unsigned char *in, int n)
+static void mdfour_tail(unsigned char *in, uint32 n)
{
unsigned char buf[128];
uint32 M[16];
- uint32 b;
-
- m->totalN += n;
-
- b = m->totalN * 8;
+ extern int remote_version;
+
+ /*
+ * Count total number of bits, modulo 2^64
+ */
+ m->totalN += n << 3;
+ if (m->totalN < (n << 3)) {
+ m->totalN2++;
+ }
+ m->totalN2 += n >> 29;
memset(buf, 0, 128);
if (n) memcpy(buf, in, n);
buf[n] = 0x80;
if (n <= 55) {
- copy4(buf+56, b);
+ copy4(buf+56, m->totalN);
+ /*
+ * Prior to protocol version 27 only the number of bits
+ * modulo 2^32 was included. MD4 requires the number
+ * of bits modulo 2^64, which was fixed starting with
+ * protocol version 27.
+ */
+ if (remote_version >= 27) {
+ copy4(buf+60, m->totalN2);
+ }
copy64(M, buf);
mdfour64(M);
} else {
- copy4(buf+120, b);
+ copy4(buf+120, m->totalN);
+ /*
+ * Prior to protocol version 27 only the number of bits
+ * modulo 2^32 was included. MD4 requires the number
+ * of bits modulo 2^64, which was fixed starting with
+ * protocol version 27.
+ */
+ if (remote_version >= 27) {
+ copy4(buf+124, m->totalN2);
+ }
copy64(M, buf);
mdfour64(M);
copy64(M, buf+64);
}
}
-void mdfour_update(struct mdfour *md, unsigned char *in, int n)
+void mdfour_update(struct mdfour *md, unsigned char *in, uint32 n)
{
uint32 M[16];
- if (n == 0) mdfour_tail(in, n);
-
m = md;
+ if (n == 0) mdfour_tail(in, n);
+
while (n >= 64) {
copy64(M, in);
mdfour64(M);
in += 64;
n -= 64;
- m->totalN += 64;
+ m->totalN += 64 << 3;
+ if (m->totalN < 64 << 3) {
+ m->totalN2++;
+ }
}
if (n) mdfour_tail(in, n);
struct mdfour {
uint32 A, B, C, D;
- uint32 totalN;
+ uint32 totalN; /* bit count, lower 32 bits */
+ uint32 totalN2; /* bit count, upper 32 bits */
};
void mdfour_begin(struct mdfour *md);
-void mdfour_update(struct mdfour *md, unsigned char *in, int n);
+void mdfour_update(struct mdfour *md, unsigned char *in, uint32 n);
void mdfour_result(struct mdfour *md, unsigned char *out);
void mdfour(unsigned char *out, unsigned char *in, int n);