Diff: sha/sha256.c

Revision:

3:e6a2c4579a4d

Child:

4:6a1d887f1cad

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sha/sha256.c	Fri Aug 02 15:07:18 2019 +0000
@@ -0,0 +1,185 @@
+#include <stdint.h>
+#include <string.h>
+
+#include "sha256.h"
+
+#define BLOCK_SIZE 64
+
+/**
+ * sha256_vector - SHA256 hash for data vector
+ * @num_elem: Number of elements in the data vector
+ * @addr: Pointers to the data areas
+ * @len: Lengths of the data blocks
+ * @mac: Buffer for the hash
+
+void sha256_vector(int num_elem, const u8 *addr[], const int *len, u8 *mac)
+{
+    struct sha256_state ctx;
+    int i;
+    sha256_init(&ctx);
+    for (i = 0; i < num_elem; i++) sha256_process(&ctx, addr[i], len[i]);
+    sha256_done(&ctx, mac);
+}
+*/
+/* ===== start - public domain SHA256 implementation ===== */
+/* This is based on SHA256 implementation in LibTomCrypt that was released into
+ * public domain by Tom St Denis. */
+/* the K array */
+static const uint32_t K[64] =
+{
+    0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
+    0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
+    0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
+    0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
+    0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
+    0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
+    0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
+    0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
+    0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
+    0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
+    0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
+    0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
+    0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
+};
+
+static uint32_t rotate(uint32_t x, int count) { return x >> count | x << (32 - count); }
+
+static int compress(struct Sha256State *md, const uint8_t *buf) // compress 512-bits
+{
+    uint32_t s[8], w[64];
+    
+    // copy state into s
+    for (int i = 0; i < 8; i++) s[i] = md->state[i];
+
+    // copy the state into 512-bits into w[0..15]
+    for (int i = 0; i < 16; i++) w[i] = (uint32_t)*(buf + 4 * i + 0) << 24 |
+                                        (uint32_t)*(buf + 4 * i + 1) << 16 |
+                                        (uint32_t)*(buf + 4 * i + 2) <<  8 |
+                                        (uint32_t)*(buf + 4 * i + 3);
+    
+    // fill w[16..63]
+    for (int i = 16; i < 64; i++)
+    {
+        const uint32_t s0 = rotate(w[i - 15],  7) ^ rotate(w[i - 15], 18) ^ (w[i - 15] >>  3);
+        const uint32_t s1 = rotate(w[i -  2], 17) ^ rotate(w[i -  2], 19) ^ (w[i -  2] >> 10);
+        w[i] = w[i - 16] + s0 + w[i - 7] + s1;
+    }
+
+    // Compress
+    for (int i = 0; i < 64; ++i)
+    {
+        const uint32_t s1 = rotate(s[4], 6) ^ rotate(s[4], 11) ^ rotate(s[4], 25);
+        const uint32_t ch = (s[4] & s[5]) ^ (~s[4] & s[6]);
+        const uint32_t t0 = s[7] + s1 + ch + K[i] + w[i];
+        const uint32_t s0 = rotate(s[0], 2) ^ rotate(s[0], 13) ^ rotate(s[0], 22);
+        const uint32_t maj = (s[0] & s[1]) ^ (s[0] & s[2]) ^ (s[1] & s[2]);
+        const uint32_t t1 = s0 + maj;
+
+        s[7] = s[6];
+        s[6] = s[5];
+        s[5] = s[4]; 
+        s[4] = s[3] + t0;
+        s[3] = s[2];
+        s[2] = s[1];
+        s[1] = s[0];
+        s[0] = t0 + t1;
+    }
+    
+    // feedback
+    for (int i = 0; i < 8; i++) md->state[i] = md->state[i] + s[i];
+
+    return 0;
+}
+
+void Sha256Start(struct Sha256State *md) // Initialize the hash state
+{
+    md->curlen = 0;
+    md->length = 0;
+    md->state[0] = 0x6A09E667UL;
+    md->state[1] = 0xBB67AE85UL;
+    md->state[2] = 0x3C6EF372UL;
+    md->state[3] = 0xA54FF53AUL;
+    md->state[4] = 0x510E527FUL;
+    md->state[5] = 0x9B05688CUL;
+    md->state[6] = 0x1F83D9ABUL;
+    md->state[7] = 0x5BE0CD19UL;
+}
+
+int Sha256Add(struct Sha256State *md, const uint8_t *in, int inlen) //Return 0 if ok; -1 on error
+{
+    if (md->curlen > sizeof(md->buf)) return -1;
+    
+    while (inlen > 0)
+    {
+        if (md->curlen == 0 && inlen >= BLOCK_SIZE)
+        {
+            if (compress(md, in) < 0) return -1;
+            md->length += BLOCK_SIZE * 8;
+            in         += BLOCK_SIZE;
+            inlen      -= BLOCK_SIZE;
+        }
+        else
+        {
+            int n = inlen < BLOCK_SIZE - md->curlen ? inlen : BLOCK_SIZE - md->curlen;
+            memcpy(md->buf + md->curlen, in, n);
+            md->curlen += n;
+            in         += n;
+            inlen      -= n;
+            if (md->curlen == BLOCK_SIZE)
+            {
+                if (compress(md, md->buf) < 0) return -1;
+                md->length += 8 * BLOCK_SIZE;
+                md->curlen  = 0;
+            }
+        }
+    }
+    return 0;
+}
+
+int Sha256Finish(struct Sha256State *md, uint8_t *out) //returns 0 on success; -1 on failure
+{
+    if (md->curlen >= sizeof(md->buf)) return -1;
+    
+    // increase the length of the message
+    md->length += md->curlen * 8;
+    
+    // append the '1' bit
+    md->buf[md->curlen++] = 0x80;
+    
+    /* if the length is currently above 56 bytes we append zeros
+     * then compress.  Then we can fall back to padding zeros and length
+     * encoding like normal.
+     */
+    if (md->curlen > 56)
+    {
+        while (md->curlen < 64) md->buf[md->curlen++] = 0;
+        compress(md, md->buf);
+        md->curlen = 0;
+    }
+    // pad upto 56 bytes of zeroes
+    while (md->curlen < 56)  md->buf[md->curlen++] = 0;
+
+    // store length
+    *(md->buf + 56 + 0) = (uint8_t) (md->length >> 56);
+    *(md->buf + 56 + 1) = (uint8_t) (md->length >> 48);
+    *(md->buf + 56 + 2) = (uint8_t) (md->length >> 40);
+    *(md->buf + 56 + 3) = (uint8_t) (md->length >> 32);
+    *(md->buf + 56 + 4) = (uint8_t) (md->length >> 24);
+    *(md->buf + 56 + 5) = (uint8_t) (md->length >> 16);
+    *(md->buf + 56 + 6) = (uint8_t) (md->length >>  8);
+    *(md->buf + 56 + 7) = (uint8_t) (md->length >>  0);
+
+
+    compress(md, md->buf);
+    
+    // copy output
+    for (int i = 0; i < 8; i++)
+    {
+        *(out + 4 * i + 0) = (uint8_t) (md->state[i] >> 24);
+        *(out + 4 * i + 1) = (uint8_t) (md->state[i] >> 16);
+        *(out + 4 * i + 2) = (uint8_t) (md->state[i] >>  8);
+        *(out + 4 * i + 3) = (uint8_t) (md->state[i] >>  0);
+    }
+    
+    return 0;
+}