sara matheu
/
CurvasElipticas
Operaciones de generacion de claves, D-H, firma y validacion.
Diff: sha256.cpp
- Revision:
- 3:74a69ff114ba
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/sha256.cpp Sat Feb 14 18:10:15 2015 +0000 @@ -0,0 +1,132 @@ +#include <cstring> +#include <fstream> +#include "sha256.h" + +const unsigned int SHA256::sha256_k[64] = //UL = uint32 + {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}; + +void SHA256::transform(const unsigned char *message, unsigned int block_nb) +{ + uint32 w[64]; + uint32 wv[8]; + uint32 t1, t2; + const unsigned char *sub_block; + int i; + int j; + for (i = 0; i < (int) block_nb; i++) { + sub_block = message + (i << 6); + for (j = 0; j < 16; j++) { + SHA2_PACK32(&sub_block[j << 2], &w[j]); + } + for (j = 16; j < 64; j++) { + w[j] = SHA256_F4(w[j - 2]) + w[j - 7] + SHA256_F3(w[j - 15]) + w[j - 16]; + } + for (j = 0; j < 8; j++) { + wv[j] = m_h[j]; + } + for (j = 0; j < 64; j++) { + t1 = wv[7] + SHA256_F2(wv[4]) + SHA2_CH(wv[4], wv[5], wv[6]) + + sha256_k[j] + w[j]; + t2 = SHA256_F1(wv[0]) + SHA2_MAJ(wv[0], wv[1], wv[2]); + wv[7] = wv[6]; + wv[6] = wv[5]; + wv[5] = wv[4]; + wv[4] = wv[3] + t1; + wv[3] = wv[2]; + wv[2] = wv[1]; + wv[1] = wv[0]; + wv[0] = t1 + t2; + } + for (j = 0; j < 8; j++) { + m_h[j] += wv[j]; + } + } +} + +void SHA256::init() +{ + m_h[0] = 0x6a09e667; + m_h[1] = 0xbb67ae85; + m_h[2] = 0x3c6ef372; + m_h[3] = 0xa54ff53a; + m_h[4] = 0x510e527f; + m_h[5] = 0x9b05688c; + m_h[6] = 0x1f83d9ab; + m_h[7] = 0x5be0cd19; + m_len = 0; + m_tot_len = 0; +} + +void SHA256::update(const unsigned char *message, unsigned int len) +{ + unsigned int block_nb; + unsigned int new_len, rem_len, tmp_len; + const unsigned char *shifted_message; + tmp_len = SHA224_256_BLOCK_SIZE - m_len; + rem_len = len < tmp_len ? len : tmp_len; + std::memcpy(&m_block[m_len], message, rem_len); + if (m_len + len < SHA224_256_BLOCK_SIZE) { + m_len += len; + return; + } + new_len = len - rem_len; + block_nb = new_len / SHA224_256_BLOCK_SIZE; + shifted_message = message + rem_len; + transform(m_block, 1); + transform(shifted_message, block_nb); + rem_len = new_len % SHA224_256_BLOCK_SIZE; + std::memcpy(m_block, &shifted_message[block_nb << 6], rem_len); + m_len = rem_len; + m_tot_len += (block_nb + 1) << 6; +} + +void SHA256::final(unsigned char *digest) +{ + unsigned int block_nb; + unsigned int pm_len; + unsigned int len_b; + int i; + block_nb = (1 + ((SHA224_256_BLOCK_SIZE - 9) + < (m_len % SHA224_256_BLOCK_SIZE))); + len_b = (m_tot_len + m_len) << 3; + pm_len = block_nb << 6; + std::memset(m_block + m_len, 0, pm_len - m_len); + m_block[m_len] = 0x80; + SHA2_UNPACK32(len_b, m_block + pm_len - 4); + transform(m_block, block_nb); + for (i = 0 ; i < 8; i++) { + SHA2_UNPACK32(m_h[i], &digest[i << 2]); + } +} + +std::string sha256(std::string input) +{ + unsigned char digest[SHA256::DIGEST_SIZE]; + std::memset(digest,0,SHA256::DIGEST_SIZE); + + SHA256 ctx = SHA256(); + ctx.init(); + ctx.update( (unsigned char*)input.c_str(), input.length()); + ctx.final(digest); + + char buf[2*SHA256::DIGEST_SIZE+1]; + buf[2*SHA256::DIGEST_SIZE] = 0; + for (int i = 0; i < SHA256::DIGEST_SIZE; i++) + std::sprintf(buf+i*2, "%02x", digest[i]); + return std::string(buf); +} \ No newline at end of file