[PATCH] Fix PPC SHA1 routine for large input buffers

The PPC SHA1 routine had an overflow which meant that it gave
incorrect results for input buffers >= 512MB.  This fixes it by
ensuring that the update of the total length in bits is done using
64-bit arithmetic.

Signed-off-by: Paul Mackerras <redacted>
---
Linus Torvalds writes:

Paul - I think the ppc SHA1_Update() overflows in 32 bits, when the length 
of the memory area to be checksummed is huge.

Yep.  I checked the assembly output of this, and it looks right, but I
haven't actually tested it by running it...

Paul.

diff --git a/ppc/sha1.c b/ppc/sha1.c
index 5ba4fc5..0820398 100644
--- a/ppc/sha1.c
+++ b/ppc/sha1.c

@@ -30,7 +30,7 @@ int SHA1_Update(SHA_CTX *c, const void *
 	unsigned long nb;
 	const unsigned char *p = ptr;
 
-	c->len += n << 3;
+	c->len += (uint64_t) n << 3;
 	while (n != 0) {
 		if (c->cnt || n < 64) {
 			nb = 64 - c->cnt;