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-rw-r--r--update.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/update.c b/update.c
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+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+/**
+ * Unified implementation (what can unified without performance impact)
+ * of the chunk processing for all SHA-2 functions
+ *
+ * @param A Wordsize-dependent constant, take a look at the code
+ * @param B Wordsize-dependent constant, take a look at the code
+ * @param C Wordsize-dependent constant, take a look at the code
+ * @param D Wordsize-dependent constant, take a look at the code
+ * @param E Wordsize-dependent constant, take a look at the code
+ * @param F Wordsize-dependent constant, take a look at the code
+ * @param G Wordsize-dependent constant, take a look at the code
+ * @param H Wordsize-dependent constant, take a look at the code
+ * @param I Wordsize-dependent constant, take a look at the code
+ * @param J Wordsize-dependent constant, take a look at the code
+ * @param K Wordsize-dependent constant, take a look at the code
+ * @param L Wordsize-dependent constant, take a look at the code
+ * @param WORD_T `__typeof()` on any wordsize-dependent variable, with exact size
+ * @param k Round constants
+ * @param w Words
+ * @param h Hash values
+ * @param work_h Space for temporary hash values
+ */
+#define SHA2_IMPLEMENTATION(A, B, C, D, E, F, G, H, I, J, K, L, WORD_T, k, w, h, work_h)\
+ memcpy(work_h, h, sizeof(work_h));\
+ \
+ memset(w, 0, 16 * sizeof(*(w)));\
+ for (i = 0; i < 16; i++)\
+ for (j = 0; j < sizeof(WORD_T); j++)\
+ w[i] |= ((WORD_T)(state->chunk[(i + 1) * sizeof(WORD_T) - j - 1])) << (j << 3);\
+ \
+ for (i = 16; i < sizeof(k) / sizeof(*(k)); i++) {\
+ w[i] = w[i - 16] + w[i - 7];\
+ w[i] += ROTR(w[i - 15], A) ^ ROTR(w[i - 15], B) ^ (w[i - 15] >> (C));\
+ w[i] += ROTR(w[i - 2], D) ^ ROTR(w[i - 2], E) ^ (w[i - 2] >> (F));\
+ }\
+ \
+ for (i = 0; i < sizeof(k) / sizeof(*(k)); i++) {\
+ s1 = (work_h[4] & work_h[5]) ^ (work_h[6] & ~(work_h[4]));\
+ s1 += work_h[7] + k[i] + w[i];\
+ s0 = (work_h[0] & work_h[1]) ^ (work_h[0] & work_h[2]) ^ (work_h[1] & work_h[2]);\
+ s1 += ROTR(work_h[4], G) ^ ROTR(work_h[4], H) ^ ROTR(work_h[4], I);\
+ s0 += ROTR(work_h[0], J) ^ ROTR(work_h[0], K) ^ ROTR(work_h[0], L);\
+ \
+ memmove(work_h + 1, work_h, 7 * sizeof(*(work_h)));\
+ work_h[4] += s1;\
+ work_h[0] = s1 + s0;\
+ }\
+ \
+ for (i = 0; i < 8; i++)\
+ h[i] += work_h[i]
+
+
+/**
+ * Process a chunk using SHA-256
+ *
+ * @param state The hashing state
+ */
+#if defined(__GNUC__)
+__attribute__((__nonnull__, __nothrow__))
+#endif
+static void
+process256(struct libsha2_state *restrict state)
+{
+ uint32_t s0, s1;
+ size_t i, j;
+#if defined(__GNUC__)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wmemset-elt-size"
+#endif
+#define ROTR(X, N) (((X) >> (N)) | ((X) << ((sizeof(uint32_t) * 8) - (N))))
+ SHA2_IMPLEMENTATION(7, 18, 3, 17, 19, 10, 6, 11, 25, 2, 13, 22, uint32_t,
+ state->k.b32, state->w.b32, state->h.b32, state->work_h.b32);
+#undef ROTR
+#if defined(__GNUC__)
+# pragma GCC diagnostic pop
+#endif
+}
+
+
+/**
+ * Process a chunk using SHA-512
+ *
+ * @param state The hashing state
+ */
+#if defined(__GNUC__)
+__attribute__((__nonnull__, __nothrow__))
+#endif
+static void
+process512(struct libsha2_state *restrict state)
+{
+ uint64_t s0, s1;
+ size_t i, j;
+#define ROTR(X, N) (((X) >> (N)) | ((X) << ((sizeof(uint64_t) * 8) - (N))))
+ SHA2_IMPLEMENTATION(1, 8, 7, 19, 61, 6, 14, 18, 41, 28, 34, 39, uint64_t,
+ state->k.b64, state->w.b64, state->h.b64, state->work_h.b64);
+#undef ROTR
+}
+
+
+/**
+ * Absorb more of the message
+ *
+ * @param state The hashing state
+ * @param message The message, in bits, must be equivalent to 0 modulus 8
+ * @param msglen The length of the message
+ */
+void
+libsha2_update(struct libsha2_state *restrict state, const char *restrict message, size_t msglen)
+{
+ size_t n, off, mlen;
+
+ msglen /= 8;
+ mlen = state->message_size / 8;
+
+ while (msglen) {
+ off = mlen % state->chunk_size;
+ n = state->chunk_size - off;
+ n = n < msglen ? n : msglen;
+ memcpy(state->chunk + off, message, n);
+ if (off + n == state->chunk_size) {
+ switch (state->algorithm) {
+ case LIBSHA2_224:
+ case LIBSHA2_256:
+ process256(state);
+ break;
+
+ default:
+ process512(state);
+ break;
+ }
+ }
+ message += n, mlen += n, msglen -= n;
+ }
+
+ state->message_size = mlen * 8;
+}