Compute the SHA-256 hex digest of a byte slice.
(data: &[u8])
| 350 | |
| 351 | /// Compute the SHA-256 hex digest of a byte slice. |
| 352 | fn sha256_hex(data: &[u8]) -> String { |
| 353 | // Minimal SHA-256 implementation to avoid adding a build-dependency. |
| 354 | // Based on the FIPS 180-4 specification. |
| 355 | |
| 356 | const K: [u32; 64] = [ |
| 357 | 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, |
| 358 | 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, |
| 359 | 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, |
| 360 | 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, |
| 361 | 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, |
| 362 | 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, |
| 363 | 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, |
| 364 | 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, |
| 365 | 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, |
| 366 | 0xc67178f2, |
| 367 | ]; |
| 368 | |
| 369 | #[inline(always)] |
| 370 | fn ch(x: u32, y: u32, z: u32) -> u32 { |
| 371 | (x & y) ^ (!x & z) |
| 372 | } |
| 373 | #[inline(always)] |
| 374 | fn maj(x: u32, y: u32, z: u32) -> u32 { |
| 375 | (x & y) ^ (x & z) ^ (y & z) |
| 376 | } |
| 377 | #[inline(always)] |
| 378 | fn ep0(x: u32) -> u32 { |
| 379 | x.rotate_right(2) ^ x.rotate_right(13) ^ x.rotate_right(22) |
| 380 | } |
| 381 | #[inline(always)] |
| 382 | fn ep1(x: u32) -> u32 { |
| 383 | x.rotate_right(6) ^ x.rotate_right(11) ^ x.rotate_right(25) |
| 384 | } |
| 385 | #[inline(always)] |
| 386 | fn sig0(x: u32) -> u32 { |
| 387 | x.rotate_right(7) ^ x.rotate_right(18) ^ (x >> 3) |
| 388 | } |
| 389 | #[inline(always)] |
| 390 | fn sig1(x: u32) -> u32 { |
| 391 | x.rotate_right(17) ^ x.rotate_right(19) ^ (x >> 10) |
| 392 | } |
| 393 | |
| 394 | let mut h: [u32; 8] = [ |
| 395 | 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, |
| 396 | 0x5be0cd19, |
| 397 | ]; |
| 398 | |
| 399 | // Pre-processing: pad the message. |
| 400 | let bit_len = (data.len() as u64) * 8; |
| 401 | let mut padded = data.to_vec(); |
| 402 | padded.push(0x80); |
| 403 | while (padded.len() % 64) != 56 { |
| 404 | padded.push(0x00); |
| 405 | } |
| 406 | padded.extend_from_slice(&bit_len.to_be_bytes()); |
| 407 | |
| 408 | // Process each 512-bit (64-byte) block. |
| 409 | for block in padded.chunks_exact(64) { |