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Diffstat (limited to '')
| -rw-r--r-- | lib/crypto/sha256.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/lib/crypto/sha256.c b/lib/crypto/sha256.c new file mode 100644 index 000000000..72a4b0b1d --- /dev/null +++ b/lib/crypto/sha256.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SHA-256, as specified in + * http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf + * + * SHA-256 code by Jean-Luc Cooke <jlcooke@certainkey.com>. + * + * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com> + * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk> + * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> + * Copyright (c) 2014 Red Hat Inc. + */ + +#include <linux/bitops.h> +#include <linux/export.h> +#include <linux/module.h> +#include <linux/string.h> +#include <crypto/sha2.h> +#include <asm/unaligned.h> + +static const u32 SHA256_K[] = { + 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, + 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, + 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, + 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, + 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, + 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, + 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, + 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, + 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, + 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, + 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, + 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, + 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, + 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, + 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, + 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2, +}; + +static inline u32 Ch(u32 x, u32 y, u32 z) +{ + return z ^ (x & (y ^ z)); +} + +static inline u32 Maj(u32 x, u32 y, u32 z) +{ + return (x & y) | (z & (x | y)); +} + +#define e0(x) (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22)) +#define e1(x) (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25)) +#define s0(x) (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3)) +#define s1(x) (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10)) + +static inline void LOAD_OP(int I, u32 *W, const u8 *input) +{ + W[I] = get_unaligned_be32((__u32 *)input + I); +} + +static inline void BLEND_OP(int I, u32 *W) +{ + W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16]; +} + +#define SHA256_ROUND(i, a, b, c, d, e, f, g, h) do { \ + u32 t1, t2; \ + t1 = h + e1(e) + Ch(e, f, g) + SHA256_K[i] + W[i]; \ + t2 = e0(a) + Maj(a, b, c); \ + d += t1; \ + h = t1 + t2; \ +} while (0) + +static void sha256_transform(u32 *state, const u8 *input, u32 *W) +{ + u32 a, b, c, d, e, f, g, h; + int i; + + /* load the input */ + for (i = 0; i < 16; i += 8) { + LOAD_OP(i + 0, W, input); + LOAD_OP(i + 1, W, input); + LOAD_OP(i + 2, W, input); + LOAD_OP(i + 3, W, input); + LOAD_OP(i + 4, W, input); + LOAD_OP(i + 5, W, input); + LOAD_OP(i + 6, W, input); + LOAD_OP(i + 7, W, input); + } + + /* now blend */ + for (i = 16; i < 64; i += 8) { + BLEND_OP(i + 0, W); + BLEND_OP(i + 1, W); + BLEND_OP(i + 2, W); + BLEND_OP(i + 3, W); + BLEND_OP(i + 4, W); + BLEND_OP(i + 5, W); + BLEND_OP(i + 6, W); + BLEND_OP(i + 7, W); + } + + /* load the state into our registers */ + a = state[0]; b = state[1]; c = state[2]; d = state[3]; + e = state[4]; f = state[5]; g = state[6]; h = state[7]; + + /* now iterate */ + for (i = 0; i < 64; i += 8) { + SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h); + SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g); + SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f); + SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e); + SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d); + SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c); + SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b); + SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a); + } + + state[0] += a; state[1] += b; state[2] += c; state[3] += d; + state[4] += e; state[5] += f; state[6] += g; state[7] += h; +} + +void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len) +{ + unsigned int partial, done; + const u8 *src; + u32 W[64]; + + partial = sctx->count & 0x3f; + sctx->count += len; + done = 0; + src = data; + + if ((partial + len) > 63) { + if (partial) { + done = -partial; + memcpy(sctx->buf + partial, data, done + 64); + src = sctx->buf; + } + + do { + sha256_transform(sctx->state, src, W); + done += 64; + src = data + done; + } while (done + 63 < len); + + memzero_explicit(W, sizeof(W)); + + partial = 0; + } + memcpy(sctx->buf + partial, src, len - done); +} +EXPORT_SYMBOL(sha256_update); + +void sha224_update(struct sha256_state *sctx, const u8 *data, unsigned int len) +{ + sha256_update(sctx, data, len); +} +EXPORT_SYMBOL(sha224_update); + +static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_words) +{ + __be32 *dst = (__be32 *)out; + __be64 bits; + unsigned int index, pad_len; + int i; + static const u8 padding[64] = { 0x80, }; + + /* Save number of bits */ + bits = cpu_to_be64(sctx->count << 3); + + /* Pad out to 56 mod 64. */ + index = sctx->count & 0x3f; + pad_len = (index < 56) ? (56 - index) : ((64+56) - index); + sha256_update(sctx, padding, pad_len); + + /* Append length (before padding) */ + sha256_update(sctx, (const u8 *)&bits, sizeof(bits)); + + /* Store state in digest */ + for (i = 0; i < digest_words; i++) + put_unaligned_be32(sctx->state[i], &dst[i]); + + /* Zeroize sensitive information. */ + memzero_explicit(sctx, sizeof(*sctx)); +} + +void sha256_final(struct sha256_state *sctx, u8 *out) +{ + __sha256_final(sctx, out, 8); +} +EXPORT_SYMBOL(sha256_final); + +void sha224_final(struct sha256_state *sctx, u8 *out) +{ + __sha256_final(sctx, out, 7); +} +EXPORT_SYMBOL(sha224_final); + +void sha256(const u8 *data, unsigned int len, u8 *out) +{ + struct sha256_state sctx; + + sha256_init(&sctx); + sha256_update(&sctx, data, len); + sha256_final(&sctx, out); +} +EXPORT_SYMBOL(sha256); + +MODULE_LICENSE("GPL"); |