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-rw-r--r--lib/sha1.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/lib/sha1.c b/lib/sha1.c
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+/*
+ * SHA transform algorithm, originally taken from code written by
+ * Peter Gutmann, and placed in the public domain.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/cryptohash.h>
+
+/* The SHA f()-functions. */
+
+#define f1(x,y,z) (z ^ (x & (y ^ z))) /* x ? y : z */
+#define f2(x,y,z) (x ^ y ^ z) /* XOR */
+#define f3(x,y,z) ((x & y) + (z & (x ^ y))) /* majority */
+
+/* The SHA Mysterious Constants */
+
+#define K1 0x5A827999L /* Rounds 0-19: sqrt(2) * 2^30 */
+#define K2 0x6ED9EBA1L /* Rounds 20-39: sqrt(3) * 2^30 */
+#define K3 0x8F1BBCDCL /* Rounds 40-59: sqrt(5) * 2^30 */
+#define K4 0xCA62C1D6L /* Rounds 60-79: sqrt(10) * 2^30 */
+
+/**
+ * sha_transform - single block SHA1 transform
+ *
+ * @digest: 160 bit digest to update
+ * @data: 512 bits of data to hash
+ * @W: 80 words of workspace (see note)
+ *
+ * This function generates a SHA1 digest for a single 512-bit block.
+ * Be warned, it does not handle padding and message digest, do not
+ * confuse it with the full FIPS 180-1 digest algorithm for variable
+ * length messages.
+ *
+ * Note: If the hash is security sensitive, the caller should be sure
+ * to clear the workspace. This is left to the caller to avoid
+ * unnecessary clears between chained hashing operations.
+ */
+void sha_transform(__u32 *digest, const char *in, __u32 *W)
+{
+ __u32 a, b, c, d, e, t, i;
+
+ for (i = 0; i < 16; i++)
+ W[i] = be32_to_cpu(((const __be32 *)in)[i]);
+
+ for (i = 0; i < 64; i++)
+ W[i+16] = rol32(W[i+13] ^ W[i+8] ^ W[i+2] ^ W[i], 1);
+
+ a = digest[0];
+ b = digest[1];
+ c = digest[2];
+ d = digest[3];
+ e = digest[4];
+
+ for (i = 0; i < 20; i++) {
+ t = f1(b, c, d) + K1 + rol32(a, 5) + e + W[i];
+ e = d; d = c; c = rol32(b, 30); b = a; a = t;
+ }
+
+ for (; i < 40; i ++) {
+ t = f2(b, c, d) + K2 + rol32(a, 5) + e + W[i];
+ e = d; d = c; c = rol32(b, 30); b = a; a = t;
+ }
+
+ for (; i < 60; i ++) {
+ t = f3(b, c, d) + K3 + rol32(a, 5) + e + W[i];
+ e = d; d = c; c = rol32(b, 30); b = a; a = t;
+ }
+
+ for (; i < 80; i ++) {
+ t = f2(b, c, d) + K4 + rol32(a, 5) + e + W[i];
+ e = d; d = c; c = rol32(b, 30); b = a; a = t;
+ }
+
+ digest[0] += a;
+ digest[1] += b;
+ digest[2] += c;
+ digest[3] += d;
+ digest[4] += e;
+}
+EXPORT_SYMBOL(sha_transform);
+
+/**
+ * sha_init - initialize the vectors for a SHA1 digest
+ * @buf: vector to initialize
+ */
+void sha_init(__u32 *buf)
+{
+ buf[0] = 0x67452301;
+ buf[1] = 0xefcdab89;
+ buf[2] = 0x98badcfe;
+ buf[3] = 0x10325476;
+ buf[4] = 0xc3d2e1f0;
+}
+