diff --git a/lib/crypto/sha256.c b/lib/crypto/sha256.c
new file mode 100644
index 0000000..66cb04b
--- /dev/null
+++ b/lib/crypto/sha256.c
@@ -0,0 +1,287 @@
+// 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/sha.h>
+#include <asm/unaligned.h>
+
+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];
+}
+
+static void sha256_transform(u32 *state, const u8 *input)
+{
+	u32 a, b, c, d, e, f, g, h, t1, t2;
+	u32 W[64];
+	int i;
+
+	/* load the input */
+	for (i = 0; i < 16; i++)
+		LOAD_OP(i, W, input);
+
+	/* now blend */
+	for (i = 16; i < 64; i++)
+		BLEND_OP(i, 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 */
+	t1 = h + e1(e) + Ch(e, f, g) + 0x428a2f98 + W[0];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0x71374491 + W[1];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0xb5c0fbcf + W[2];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0xe9b5dba5 + W[3];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0x3956c25b + W[4];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0x59f111f1 + W[5];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0x923f82a4 + W[6];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0xab1c5ed5 + W[7];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	t1 = h + e1(e) + Ch(e, f, g) + 0xd807aa98 + W[8];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0x12835b01 + W[9];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0x243185be + W[10];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0x550c7dc3 + W[11];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0x72be5d74 + W[12];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0x80deb1fe + W[13];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0x9bdc06a7 + W[14];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0xc19bf174 + W[15];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	t1 = h + e1(e) + Ch(e, f, g) + 0xe49b69c1 + W[16];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0xefbe4786 + W[17];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0x0fc19dc6 + W[18];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0x240ca1cc + W[19];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0x2de92c6f + W[20];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0x4a7484aa + W[21];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0x5cb0a9dc + W[22];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0x76f988da + W[23];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	t1 = h + e1(e) + Ch(e, f, g) + 0x983e5152 + W[24];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0xa831c66d + W[25];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0xb00327c8 + W[26];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0xbf597fc7 + W[27];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0xc6e00bf3 + W[28];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0xd5a79147 + W[29];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0x06ca6351 + W[30];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0x14292967 + W[31];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	t1 = h + e1(e) + Ch(e, f, g) + 0x27b70a85 + W[32];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0x2e1b2138 + W[33];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0x4d2c6dfc + W[34];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0x53380d13 + W[35];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0x650a7354 + W[36];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0x766a0abb + W[37];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0x81c2c92e + W[38];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0x92722c85 + W[39];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	t1 = h + e1(e) + Ch(e, f, g) + 0xa2bfe8a1 + W[40];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0xa81a664b + W[41];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0xc24b8b70 + W[42];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0xc76c51a3 + W[43];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0xd192e819 + W[44];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0xd6990624 + W[45];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0xf40e3585 + W[46];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0x106aa070 + W[47];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	t1 = h + e1(e) + Ch(e, f, g) + 0x19a4c116 + W[48];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0x1e376c08 + W[49];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0x2748774c + W[50];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0x34b0bcb5 + W[51];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0x391c0cb3 + W[52];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0x4ed8aa4a + W[53];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0x5b9cca4f + W[54];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0x682e6ff3 + W[55];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	t1 = h + e1(e) + Ch(e, f, g) + 0x748f82ee + W[56];
+	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
+	t1 = g + e1(d) + Ch(d, e, f) + 0x78a5636f + W[57];
+	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
+	t1 = f + e1(c) + Ch(c, d, e) + 0x84c87814 + W[58];
+	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
+	t1 = e + e1(b) + Ch(b, c, d) + 0x8cc70208 + W[59];
+	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
+	t1 = d + e1(a) + Ch(a, b, c) + 0x90befffa + W[60];
+	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
+	t1 = c + e1(h) + Ch(h, a, b) + 0xa4506ceb + W[61];
+	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
+	t1 = b + e1(g) + Ch(g, h, a) + 0xbef9a3f7 + W[62];
+	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
+	t1 = a + e1(f) + Ch(f, g, h) + 0xc67178f2 + W[63];
+	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
+
+	state[0] += a; state[1] += b; state[2] += c; state[3] += d;
+	state[4] += e; state[5] += f; state[6] += g; state[7] += h;
+
+	/* clear any sensitive info... */
+	a = b = c = d = e = f = g = h = t1 = t2 = 0;
+	memzero_explicit(W, 64 * sizeof(u32));
+}
+
+int sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
+{
+	unsigned int partial, done;
+	const u8 *src;
+
+	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);
+			done += 64;
+			src = data + done;
+		} while (done + 63 < len);
+
+		partial = 0;
+	}
+	memcpy(sctx->buf + partial, src, len - done);
+
+	return 0;
+}
+EXPORT_SYMBOL(sha256_update);
+
+int sha224_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
+{
+	return sha256_update(sctx, data, len);
+}
+EXPORT_SYMBOL(sha224_update);
+
+static int __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. */
+	memset(sctx, 0, sizeof(*sctx));
+
+	return 0;
+}
+
+int sha256_final(struct sha256_state *sctx, u8 *out)
+{
+	return __sha256_final(sctx, out, 8);
+}
+EXPORT_SYMBOL(sha256_final);
+
+int sha224_final(struct sha256_state *sctx, u8 *out)
+{
+	return __sha256_final(sctx, out, 7);
+}
+EXPORT_SYMBOL(sha224_final);
+
+MODULE_LICENSE("GPL");