/*
   * FIPS-180-2 compliant SHA-256 implementation
   *
   * Copyright (C) 2001-2003  Christophe Devine
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #ifndef USE_HOSTCC
  #include <common.h>
  #include <linux/string.h>
  #else
  #include <string.h>
  #endif /* USE_HOSTCC */
  #include <watchdog.h>
  #include <u-boot/sha256.h>
  
  /*
   * 32-bit integer manipulation macros (big endian)
   */
  #ifndef GET_UINT32_BE
  #define GET_UINT32_BE(n,b,i) {				\
  	(n) = ( (unsigned long) (b)[(i)    ] << 24 )	\
  	    | ( (unsigned long) (b)[(i) + 1] << 16 )	\
  	    | ( (unsigned long) (b)[(i) + 2] <<  8 )	\
  	    | ( (unsigned long) (b)[(i) + 3]       );	\
  }
  #endif
  #ifndef PUT_UINT32_BE
  #define PUT_UINT32_BE(n,b,i) {				\
  	(b)[(i)    ] = (unsigned char) ( (n) >> 24 );	\
  	(b)[(i) + 1] = (unsigned char) ( (n) >> 16 );	\
  	(b)[(i) + 2] = (unsigned char) ( (n) >>  8 );	\
  	(b)[(i) + 3] = (unsigned char) ( (n)       );	\
  }
  #endif
  
  void sha256_starts(sha256_context * ctx)
  {
  	ctx->total[0] = 0;
  	ctx->total[1] = 0;
  
  	ctx->state[0] = 0x6A09E667;
  	ctx->state[1] = 0xBB67AE85;
  	ctx->state[2] = 0x3C6EF372;
  	ctx->state[3] = 0xA54FF53A;
  	ctx->state[4] = 0x510E527F;
  	ctx->state[5] = 0x9B05688C;
  	ctx->state[6] = 0x1F83D9AB;
  	ctx->state[7] = 0x5BE0CD19;
  }
  
  static void sha256_process(sha256_context *ctx, const uint8_t data[64])
  {
  	uint32_t temp1, temp2;
  	uint32_t W[64];
  	uint32_t A, B, C, D, E, F, G, H;
  
  	GET_UINT32_BE(W[0], data, 0);
  	GET_UINT32_BE(W[1], data, 4);
  	GET_UINT32_BE(W[2], data, 8);
  	GET_UINT32_BE(W[3], data, 12);
  	GET_UINT32_BE(W[4], data, 16);
  	GET_UINT32_BE(W[5], data, 20);
  	GET_UINT32_BE(W[6], data, 24);
  	GET_UINT32_BE(W[7], data, 28);
  	GET_UINT32_BE(W[8], data, 32);
  	GET_UINT32_BE(W[9], data, 36);
  	GET_UINT32_BE(W[10], data, 40);
  	GET_UINT32_BE(W[11], data, 44);
  	GET_UINT32_BE(W[12], data, 48);
  	GET_UINT32_BE(W[13], data, 52);
  	GET_UINT32_BE(W[14], data, 56);
  	GET_UINT32_BE(W[15], data, 60);
  
  #define SHR(x,n) ((x & 0xFFFFFFFF) >> n)
  #define ROTR(x,n) (SHR(x,n) | (x << (32 - n)))
  
  #define S0(x) (ROTR(x, 7) ^ ROTR(x,18) ^ SHR(x, 3))
  #define S1(x) (ROTR(x,17) ^ ROTR(x,19) ^ SHR(x,10))
  
  #define S2(x) (ROTR(x, 2) ^ ROTR(x,13) ^ ROTR(x,22))
  #define S3(x) (ROTR(x, 6) ^ ROTR(x,11) ^ ROTR(x,25))
  
  #define F0(x,y,z) ((x & y) | (z & (x | y)))
  #define F1(x,y,z) (z ^ (x & (y ^ z)))
  
  #define R(t)					\
  (						\
  	W[t] = S1(W[t - 2]) + W[t - 7] +	\
  		S0(W[t - 15]) + W[t - 16]	\
  )
  
  #define P(a,b,c,d,e,f,g,h,x,K) {		\
  	temp1 = h + S3(e) + F1(e,f,g) + K + x;	\
  	temp2 = S2(a) + F0(a,b,c);		\
  	d += temp1; h = temp1 + temp2;		\
  }
  
  	A = ctx->state[0];
  	B = ctx->state[1];
  	C = ctx->state[2];
  	D = ctx->state[3];
  	E = ctx->state[4];
  	F = ctx->state[5];
  	G = ctx->state[6];
  	H = ctx->state[7];
  
  	P(A, B, C, D, E, F, G, H, W[0], 0x428A2F98);
  	P(H, A, B, C, D, E, F, G, W[1], 0x71374491);
  	P(G, H, A, B, C, D, E, F, W[2], 0xB5C0FBCF);
  	P(F, G, H, A, B, C, D, E, W[3], 0xE9B5DBA5);
  	P(E, F, G, H, A, B, C, D, W[4], 0x3956C25B);
  	P(D, E, F, G, H, A, B, C, W[5], 0x59F111F1);
  	P(C, D, E, F, G, H, A, B, W[6], 0x923F82A4);
  	P(B, C, D, E, F, G, H, A, W[7], 0xAB1C5ED5);
  	P(A, B, C, D, E, F, G, H, W[8], 0xD807AA98);
  	P(H, A, B, C, D, E, F, G, W[9], 0x12835B01);
  	P(G, H, A, B, C, D, E, F, W[10], 0x243185BE);
  	P(F, G, H, A, B, C, D, E, W[11], 0x550C7DC3);
  	P(E, F, G, H, A, B, C, D, W[12], 0x72BE5D74);
  	P(D, E, F, G, H, A, B, C, W[13], 0x80DEB1FE);
  	P(C, D, E, F, G, H, A, B, W[14], 0x9BDC06A7);
  	P(B, C, D, E, F, G, H, A, W[15], 0xC19BF174);
  	P(A, B, C, D, E, F, G, H, R(16), 0xE49B69C1);
  	P(H, A, B, C, D, E, F, G, R(17), 0xEFBE4786);
  	P(G, H, A, B, C, D, E, F, R(18), 0x0FC19DC6);
  	P(F, G, H, A, B, C, D, E, R(19), 0x240CA1CC);
  	P(E, F, G, H, A, B, C, D, R(20), 0x2DE92C6F);
  	P(D, E, F, G, H, A, B, C, R(21), 0x4A7484AA);
  	P(C, D, E, F, G, H, A, B, R(22), 0x5CB0A9DC);
  	P(B, C, D, E, F, G, H, A, R(23), 0x76F988DA);
  	P(A, B, C, D, E, F, G, H, R(24), 0x983E5152);
  	P(H, A, B, C, D, E, F, G, R(25), 0xA831C66D);
  	P(G, H, A, B, C, D, E, F, R(26), 0xB00327C8);
  	P(F, G, H, A, B, C, D, E, R(27), 0xBF597FC7);
  	P(E, F, G, H, A, B, C, D, R(28), 0xC6E00BF3);
  	P(D, E, F, G, H, A, B, C, R(29), 0xD5A79147);
  	P(C, D, E, F, G, H, A, B, R(30), 0x06CA6351);
  	P(B, C, D, E, F, G, H, A, R(31), 0x14292967);
  	P(A, B, C, D, E, F, G, H, R(32), 0x27B70A85);
  	P(H, A, B, C, D, E, F, G, R(33), 0x2E1B2138);
  	P(G, H, A, B, C, D, E, F, R(34), 0x4D2C6DFC);
  	P(F, G, H, A, B, C, D, E, R(35), 0x53380D13);
  	P(E, F, G, H, A, B, C, D, R(36), 0x650A7354);
  	P(D, E, F, G, H, A, B, C, R(37), 0x766A0ABB);
  	P(C, D, E, F, G, H, A, B, R(38), 0x81C2C92E);
  	P(B, C, D, E, F, G, H, A, R(39), 0x92722C85);
  	P(A, B, C, D, E, F, G, H, R(40), 0xA2BFE8A1);
  	P(H, A, B, C, D, E, F, G, R(41), 0xA81A664B);
  	P(G, H, A, B, C, D, E, F, R(42), 0xC24B8B70);
  	P(F, G, H, A, B, C, D, E, R(43), 0xC76C51A3);
  	P(E, F, G, H, A, B, C, D, R(44), 0xD192E819);
  	P(D, E, F, G, H, A, B, C, R(45), 0xD6990624);
  	P(C, D, E, F, G, H, A, B, R(46), 0xF40E3585);
  	P(B, C, D, E, F, G, H, A, R(47), 0x106AA070);
  	P(A, B, C, D, E, F, G, H, R(48), 0x19A4C116);
  	P(H, A, B, C, D, E, F, G, R(49), 0x1E376C08);
  	P(G, H, A, B, C, D, E, F, R(50), 0x2748774C);
  	P(F, G, H, A, B, C, D, E, R(51), 0x34B0BCB5);
  	P(E, F, G, H, A, B, C, D, R(52), 0x391C0CB3);
  	P(D, E, F, G, H, A, B, C, R(53), 0x4ED8AA4A);
  	P(C, D, E, F, G, H, A, B, R(54), 0x5B9CCA4F);
  	P(B, C, D, E, F, G, H, A, R(55), 0x682E6FF3);
  	P(A, B, C, D, E, F, G, H, R(56), 0x748F82EE);
  	P(H, A, B, C, D, E, F, G, R(57), 0x78A5636F);
  	P(G, H, A, B, C, D, E, F, R(58), 0x84C87814);
  	P(F, G, H, A, B, C, D, E, R(59), 0x8CC70208);
  	P(E, F, G, H, A, B, C, D, R(60), 0x90BEFFFA);
  	P(D, E, F, G, H, A, B, C, R(61), 0xA4506CEB);
  	P(C, D, E, F, G, H, A, B, R(62), 0xBEF9A3F7);
  	P(B, C, D, E, F, G, H, A, R(63), 0xC67178F2);
  
  	ctx->state[0] += A;
  	ctx->state[1] += B;
  	ctx->state[2] += C;
  	ctx->state[3] += D;
  	ctx->state[4] += E;
  	ctx->state[5] += F;
  	ctx->state[6] += G;
  	ctx->state[7] += H;
  }
  
  void sha256_update(sha256_context *ctx, const uint8_t *input, uint32_t length)
  {
  	uint32_t left, fill;
  
  	if (!length)
  		return;
  
  	left = ctx->total[0] & 0x3F;
  	fill = 64 - left;
  
  	ctx->total[0] += length;
  	ctx->total[0] &= 0xFFFFFFFF;
  
  	if (ctx->total[0] < length)
  		ctx->total[1]++;
  
  	if (left && length >= fill) {
  		memcpy((void *) (ctx->buffer + left), (void *) input, fill);
  		sha256_process(ctx, ctx->buffer);
  		length -= fill;
  		input += fill;
  		left = 0;
  	}
  
  	while (length >= 64) {
  		sha256_process(ctx, input);
  		length -= 64;
  		input += 64;
  	}
  
  	if (length)
  		memcpy((void *) (ctx->buffer + left), (void *) input, length);
  }
  
  static uint8_t sha256_padding[64] = {
  	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  };
  
  void sha256_finish(sha256_context * ctx, uint8_t digest[32])
  {
  	uint32_t last, padn;
  	uint32_t high, low;
  	uint8_t msglen[8];
  
  	high = ((ctx->total[0] >> 29)
  		| (ctx->total[1] << 3));
  	low = (ctx->total[0] << 3);
  
  	PUT_UINT32_BE(high, msglen, 0);
  	PUT_UINT32_BE(low, msglen, 4);
  
  	last = ctx->total[0] & 0x3F;
  	padn = (last < 56) ? (56 - last) : (120 - last);
  
  	sha256_update(ctx, sha256_padding, padn);
  	sha256_update(ctx, msglen, 8);
  
  	PUT_UINT32_BE(ctx->state[0], digest, 0);
  	PUT_UINT32_BE(ctx->state[1], digest, 4);
  	PUT_UINT32_BE(ctx->state[2], digest, 8);
  	PUT_UINT32_BE(ctx->state[3], digest, 12);
  	PUT_UINT32_BE(ctx->state[4], digest, 16);
  	PUT_UINT32_BE(ctx->state[5], digest, 20);
  	PUT_UINT32_BE(ctx->state[6], digest, 24);
  	PUT_UINT32_BE(ctx->state[7], digest, 28);
  }
  
  /*
   * Output = SHA-256( input buffer ). Trigger the watchdog every 'chunk_sz'
   * bytes of input processed.
   */
  void sha256_csum_wd(const unsigned char *input, unsigned int ilen,
  		unsigned char *output, unsigned int chunk_sz)
  {
  	sha256_context ctx;
  #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
  	const unsigned char *end;
  	unsigned char *curr;
  	int chunk;
  #endif
  
  	sha256_starts(&ctx);
  
  #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
  	curr = (unsigned char *)input;
  	end = input + ilen;
  	while (curr < end) {
  		chunk = end - curr;
  		if (chunk > chunk_sz)
  			chunk = chunk_sz;
  		sha256_update(&ctx, curr, chunk);
  		curr += chunk;
  		WATCHDOG_RESET();
  	}
  #else
  	sha256_update(&ctx, input, ilen);
  #endif
  
  	sha256_finish(&ctx, output);
  }