//---------------------------------------------------------------------------------------------------------------------------------------------- // to compile on command line: // // cc -O3 -o sha256inv sha256inv.cpp // //---------------------------------------------------------------------------------------------------------------------------------------------- // 6/30/2017 Nathan Mariels // (mt autocode to C ver 0.34) // // input : block <16 words> // // output: input data // internal states of compression function for 64 rounds of sha256 // hash of input block // // internal states, rounds 1-47 reset to all zero // // internal states, rounds 1-64, with 1-47 being recreated with compression inverse function // input data - recreated from rounds 48-64 // //---------------------------------------------------------------------------------------------------------------------------------------------- //---------------------------------------------------------------------------------------------------------------------------------------------- // include #include #include #include //---------------------------------------------------------------------------------------------------------------------------------------------- // macros #define loop(X,Y) for(X=0;X<(Y);X++) #define fill(X,Y,Z) for(int filltemp=0;filltemp<(Y);filltemp++) X[filltemp]=(Z) #define copy(X,Y,Z) for(int copytemp=0;copytemp<(Z);copytemp++) X[copytemp]=Y[copytemp] #define c_char_to_hex(X) ((((X)>='0')&&((X)<='9'))?((X)-'0'):(((((X)|32)>='a')&&(((X)|32)<='f'))?(((X)|32)-'a'+10):0)) #define sha256_rightrotate(X,Y) (((X)>>(Y))|((X)<<(32-(Y)))) #define sha256_rightshift(X,Y) (((X)>>(Y))) #define sha256_ws0(X) (sha256_rightrotate((X), 7)^sha256_rightrotate((X),18)^sha256_rightshift((X),3)) #define sha256_ws1(X) (sha256_rightrotate((X),17)^sha256_rightrotate((X),19)^sha256_rightshift((X),10)) #define sha256_s0(X) (sha256_rightrotate((X), 2)^sha256_rightrotate((X),13)^sha256_rightrotate((X),22)) #define sha256_s1(X) (sha256_rightrotate((X), 6)^sha256_rightrotate((X),11)^sha256_rightrotate((X),25)) #define sha256_xa(W,X,Y,Z) (((W)&(X))^((Y)&(Z))) //---------------------------------------------------------------------------------------------------------------------------------------------- // types typedef unsigned int uint32; //---------------------------------------------------------------------------------------------------------------------------------------------- // const const uint32 ivec_k[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 }; const uint32 sha256_k[64] = { 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 }; //---------------------------------------------------------------------------------------------------------------------------------------------- // structs typedef struct mt_sha256_state { uint32 a[68]; uint32 b[68]; } mt_sha256_state; //---------------------------------------------------------------------------------------------------------------------------------------------- // globals //---------------------------------------------------------------------------------------------------------------------------------------------- // prototypes uint32 mt_cmd_line_get_hex (const char *ptr); int main (int argc, const char * argv[]); void mt_print_rounds (mt_sha256_state *hs); void mt_print_hash (mt_sha256_state *hs); //---------------------------------------------------------------------------------------------------------------------------------------------- // code int main (int argc, const char * argv[]) { mt_sha256_state *hs, *h1, sha_state; int i; hs = &sha_state; h1 = &sha_state; // block data if (argc == 1) { printf ("\nno args - using example of \"abc\"\n"); hs->b[4] = 0x61626380; loop (i, 14) hs->b[i+5] = 0; hs->b[19] = 0x18; } else if (argc == 17) { loop (i, 16) hs->b[i+4] = mt_cmd_line_get_hex (argv[i+1]); } else { printf ("\nsha256inv - computes the SHA256 hash of a single block of data in raw format,"); printf ("\nshowing internal states, then clears first 48 rounds and recreates input data.\n\n"); printf ("block : <1 bit - end bit = 1> <(447 - N) bits zero padding> <64 bit - length in bits>\n\n"); printf ("example 1: ./sha256inv 61626380 0 0 0 0 0 0 0 0 0 0 0 0 0 0 18\n"); printf ("This will compute the SHA256 hash of the string \"abc\". It should be: BA7816BF .... F20015AD\n\n"); return 0; } // ivec loop (i, 4) { hs->a[i] = ivec_k [3-i]; hs->b[i] = ivec_k [7-i]; } printf ("\nblock: "); loop (i, 16) printf (" %08X", h1->b[i+4]); loop (i, 64) { if ((i > 13) && (i < 62)) hs->b[i+6] += sha256_ws1(hs->b[i+4]); if ((i > 8) && (i < 57)) hs->b[i+11] += hs->b[i+4]; if ((i > 0) && (i < 49)) hs->b[i+19] += sha256_ws0(hs->b[i+4]); if ( (i < 48)) hs->b[i+20] = hs->b[i+4]; hs->b[i+4] = hs->b[i+4] + sha256_k[i] + hs->a[i] + hs->b[i] + sha256_s1 (hs->b[i+3]) + (hs->b[i+3] & hs->b[i+2]) + (~hs->b[i+3] & hs->b[i+1]); hs->a[i+4] = hs->b[i+4] - hs->a[i] + sha256_s0 (hs->a[i+3]) + ((((hs->a[i+3] ^ hs->a[i+1]) & hs->a[i+2]) ^ (hs->a[i+1] & hs->a[i+3]))); } mt_print_rounds (hs); mt_print_hash (hs); //---------------------------------- printf ("\n\n\n---- zero first 48 rounds ----\n"); loop (i, 48) { hs->b[i] = 0; hs->a[i] = 0; } mt_print_rounds (hs); printf ("\n\n\n---- rebuild first 48 rounds ----\n"); for (i=47; i>=0; i--) { hs->a[i] = hs->b[i+4] - hs->a[i+4] + sha256_s0 (hs->a[i+3]) + ((((hs->a[i+3] ^ hs->a[i+1]) & hs->a[i+2]) ^ (hs->a[i+1] & hs->a[i+3]))); hs->b[i] = sha256_s1 (hs->b[i+19]) - sha256_s1 (hs->b[i+12]) - sha256_s1 (hs->b[i+3]) + sha256_k[i+16] - sha256_k[i+9] - sha256_k[i] - hs->b[i+20] + hs->b[i+16] + hs->b[i+13] - hs->b[i+9] + hs->b[i+4] + hs->a[i+16] - hs->a[i+9] - hs->a[i] + ( hs->b[i+19] & hs->b[i+18]) - ( hs->b[i+12] & hs->b[i+11]) - ( hs->b[i+3] & hs->b[i+2]) + (~hs->b[i+19] & hs->b[i+17]) - (~hs->b[i+12] & hs->b[i+10]) - (~hs->b[i+3] & hs->b[i+1]) + sha256_ws0 (- hs->b[i+1] - sha256_k[i+1] - hs->a[i+1] - sha256_s1 (hs->b[i+4]) - (hs->b[i+4] & hs->b[i+3]) - (~hs->b[i+4] & hs->b[i+2]) + hs->b[i+5]) + sha256_ws1 (- hs->b[i+14] - sha256_k[i+14] - hs->a[i+14] - sha256_s1 (hs->b[i+17]) - (hs->b[i+17] & hs->b[i+16]) - (~hs->b[i+17] & hs->b[i+15]) + hs->b[i+18]); } mt_print_rounds (hs); mt_print_hash (hs); printf ("\n\n\n---- rebuild input data ----\n"); loop (i, 16) printf (" %08X", hs->b[i+4] - hs->b[i] - sha256_k[i] - hs->a[i] - sha256_s1 (hs->b[i+3]) - (hs->b[i+3] & hs->b[i+2]) - (~hs->b[i+3] & hs->b[i+1])); printf ("\n\n"); return (0); } //---------------------------------------------------------------------------------------------------------------------------------------------- void mt_print_hash (mt_sha256_state *hs) { int i; printf ("\n\nhash : "); loop (i, 4) printf (" %08X", ivec_k[i ] + hs->a[67-i]); loop (i, 4) printf (" %08X", ivec_k[i+4] + hs->b[67-i]); } //---------------------------------------------------------------------------------------------------------------------------------------------- void mt_print_rounds (mt_sha256_state *hs) { int i, j; printf ("\n\nRound A B C D E F G H"); loop (i, 64) { printf ("\n %2d ", i + 1); loop (j, 4) printf (" %08X", hs->a[i-j+3]); loop (j, 4) printf (" %08X", hs->b[i-j+3]); } } //---------------------------------------------------------------------------------------------------------------------------------------------- uint32 mt_cmd_line_get_hex (const char *ptr) { int x = 0; uint32 r = 0; while ((*ptr) && (x < 8)) { r = r << 4; r = r + c_char_to_hex (*ptr); ptr++; x++; } return (r); } //----------------------------------------------------------------------------------------------------------------------------------------------