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Diffstat (limited to 'lib/sha1.c')
| -rw-r--r-- | lib/sha1.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/lib/sha1.c b/lib/sha1.c new file mode 100644 index 00000000000..2f7f1148dfd --- /dev/null +++ b/lib/sha1.c @@ -0,0 +1,96 @@ +/* + * 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 __u32 *)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; +} + |