bpo-30694: Upgrade Modules/expat/ to libexpat 2.2.1 (#2300)

New file: Modules/expat/siphash.h.

1 files changed, 344 insertions, 0 deletions

diff --git a/Modules/expat/siphash.h b/Modules/expat/siphash.h
new file mode 100644
index 0000000..23b56d2
--- /dev/null
+++ b/Modules/expat/siphash.h
@@ -0,0 +1,344 @@
+/* ==========================================================================
+ * siphash.h - SipHash-2-4 in a single header file
+ * --------------------------------------------------------------------------
+ * Derived by William Ahern from the reference implementation[1] published[2]
+ * by Jean-Philippe Aumasson and Daniel J. Berstein. Licensed in kind.
+ * by Jean-Philippe Aumasson and Daniel J. Berstein.
+ * Minimal changes by Sebastian Pipping on top, details below.
+ * Licensed under the CC0 Public Domain Dedication license.
+ *
+ * 1. https://www.131002.net/siphash/siphash24.c
+ * 2. https://www.131002.net/siphash/
+ * --------------------------------------------------------------------------
+ * HISTORY:
+ *
+ * 2017-06-10  (Sebastian Pipping)
+ *   - Clarify license note in the header
+ *   - Address C89 issues:
+ *     - Stop using inline keyword (and let compiler decide)
+ *     - Turn integer suffix ULL to UL
+ *     - Replace _Bool by int
+ *     - Turn macro siphash24 into a function
+ *     - Address invalid conversion (void pointer) by explicit cast
+ *   - Always expose sip24_valid (for self-tests)
+ *
+ * 2012-11-04 - Born.  (William Ahern)
+ * --------------------------------------------------------------------------
+ * USAGE:
+ *
+ * SipHash-2-4 takes as input two 64-bit words as the key, some number of
+ * message bytes, and outputs a 64-bit word as the message digest. This
+ * implementation employs two data structures: a struct sipkey for
+ * representing the key, and a struct siphash for representing the hash
+ * state.
+ *
+ * For converting a 16-byte unsigned char array to a key, use either the
+ * macro sip_keyof or the routine sip_tokey. The former instantiates a
+ * compound literal key, while the latter requires a key object as a
+ * parameter.
+ *
+ * 	unsigned char secret[16];
+ * 	arc4random_buf(secret, sizeof secret);
+ * 	struct sipkey *key = sip_keyof(secret);
+ *
+ * For hashing a message, use either the convenience macro siphash24 or the
+ * routines sip24_init, sip24_update, and sip24_final.
+ *
+ * 	struct siphash state;
+ * 	void *msg;
+ * 	size_t len;
+ * 	uint64_t hash;
+ *
+ * 	sip24_init(&state, key);
+ * 	sip24_update(&state, msg, len);
+ * 	hash = sip24_final(&state);
+ *
+ * or
+ *
+ * 	hash = siphash24(msg, len, key);
+ *
+ * To convert the 64-bit hash value to a canonical 8-byte little-endian
+ * binary representation, use either the macro sip_binof or the routine
+ * sip_tobin. The former instantiates and returns a compound literal array,
+ * while the latter requires an array object as a parameter.
+ * --------------------------------------------------------------------------
+ * NOTES:
+ *
+ * o Neither sip_keyof, sip_binof, nor siphash24 will work with compilers
+ *   lacking compound literal support. Instead, you must use the lower-level
+ *   interfaces which take as parameters the temporary state objects.
+ *
+ * o Uppercase macros may evaluate parameters more than once. Lowercase
+ *   macros should not exhibit any such side effects.
+ * ==========================================================================
+ */
+#ifndef SIPHASH_H
+#define SIPHASH_H
+
+#include <stddef.h> /* size_t */
+#include <stdint.h> /* uint64_t uint32_t uint8_t */
+
+
+#define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
+
+#define SIP_U32TO8_LE(p, v) \
+	(p)[0] = (uint8_t)((v) >>  0); (p)[1] = (uint8_t)((v) >>  8); \
+	(p)[2] = (uint8_t)((v) >> 16); (p)[3] = (uint8_t)((v) >> 24);
+
+#define SIP_U64TO8_LE(p, v) \
+	SIP_U32TO8_LE((p) + 0, (uint32_t)((v) >>  0)); \
+	SIP_U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
+
+#define SIP_U8TO64_LE(p) \
+	(((uint64_t)((p)[0]) <<  0) | \
+	 ((uint64_t)((p)[1]) <<  8) | \
+	 ((uint64_t)((p)[2]) << 16) | \
+	 ((uint64_t)((p)[3]) << 24) | \
+	 ((uint64_t)((p)[4]) << 32) | \
+	 ((uint64_t)((p)[5]) << 40) | \
+	 ((uint64_t)((p)[6]) << 48) | \
+	 ((uint64_t)((p)[7]) << 56))
+
+
+#define SIPHASH_INITIALIZER { 0, 0, 0, 0, { 0 }, 0, 0 }
+
+struct siphash {
+	uint64_t v0, v1, v2, v3;
+
+	unsigned char buf[8], *p;
+	uint64_t c;
+}; /* struct siphash */
+
+
+#define SIP_KEYLEN 16
+
+struct sipkey {
+	uint64_t k[2];
+}; /* struct sipkey */
+
+#define sip_keyof(k) sip_tokey(&(struct sipkey){ { 0 } }, (k))
+
+static struct sipkey *sip_tokey(struct sipkey *key, const void *src) {
+	key->k[0] = SIP_U8TO64_LE((const unsigned char *)src);
+	key->k[1] = SIP_U8TO64_LE((const unsigned char *)src + 8);
+	return key;
+} /* sip_tokey() */
+
+
+#define sip_binof(v) sip_tobin((unsigned char[8]){ 0 }, (v))
+
+static void *sip_tobin(void *dst, uint64_t u64) {
+	SIP_U64TO8_LE((unsigned char *)dst, u64);
+	return dst;
+} /* sip_tobin() */
+
+
+static void sip_round(struct siphash *H, const int rounds) {
+	int i;
+
+	for (i = 0; i < rounds; i++) {
+		H->v0 += H->v1;
+		H->v1 = SIP_ROTL(H->v1, 13);
+		H->v1 ^= H->v0;
+		H->v0 = SIP_ROTL(H->v0, 32);
+
+		H->v2 += H->v3;
+		H->v3 = SIP_ROTL(H->v3, 16);
+		H->v3 ^= H->v2;
+
+		H->v0 += H->v3;
+		H->v3 = SIP_ROTL(H->v3, 21);
+		H->v3 ^= H->v0;
+
+		H->v2 += H->v1;
+		H->v1 = SIP_ROTL(H->v1, 17);
+		H->v1 ^= H->v2;
+		H->v2 = SIP_ROTL(H->v2, 32);
+	}
+} /* sip_round() */
+
+
+static struct siphash *sip24_init(struct siphash *H, const struct sipkey *key) {
+	H->v0 = 0x736f6d6570736575UL ^ key->k[0];
+	H->v1 = 0x646f72616e646f6dUL ^ key->k[1];
+	H->v2 = 0x6c7967656e657261UL ^ key->k[0];
+	H->v3 = 0x7465646279746573UL ^ key->k[1];
+
+	H->p = H->buf;
+	H->c = 0;
+
+	return H;
+} /* sip24_init() */
+
+
+#define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)])
+
+static struct siphash *sip24_update(struct siphash *H, const void *src, size_t len) {
+	const unsigned char *p = (const unsigned char *)src, *pe = p + len;
+	uint64_t m;
+
+	do {
+		while (p < pe && H->p < sip_endof(H->buf))
+			*H->p++ = *p++;
+
+		if (H->p < sip_endof(H->buf))
+			break;
+
+		m = SIP_U8TO64_LE(H->buf);
+		H->v3 ^= m;
+		sip_round(H, 2);
+		H->v0 ^= m;
+
+		H->p = H->buf;
+		H->c += 8;
+	} while (p < pe);
+
+	return H;
+} /* sip24_update() */
+
+
+static uint64_t sip24_final(struct siphash *H) {
+	char left = H->p - H->buf;
+	uint64_t b = (H->c + left) << 56;
+
+	switch (left) {
+	case 7: b |= (uint64_t)H->buf[6] << 48;
+	case 6: b |= (uint64_t)H->buf[5] << 40;
+	case 5: b |= (uint64_t)H->buf[4] << 32;
+	case 4: b |= (uint64_t)H->buf[3] << 24;
+	case 3: b |= (uint64_t)H->buf[2] << 16;
+	case 2: b |= (uint64_t)H->buf[1] << 8;
+	case 1: b |= (uint64_t)H->buf[0] << 0;
+	case 0: break;
+	}
+
+	H->v3 ^= b;
+	sip_round(H, 2);
+	H->v0 ^= b;
+	H->v2 ^= 0xff;
+	sip_round(H, 4);
+
+	return H->v0 ^ H->v1 ^ H->v2  ^ H->v3;
+} /* sip24_final() */
+
+
+static uint64_t siphash24(const void *src, size_t len, const struct sipkey *key) {
+	struct siphash state = SIPHASH_INITIALIZER;
+	return sip24_final(sip24_update(sip24_init(&state, key), src, len));
+} /* siphash24() */
+
+
+/*
+ * SipHash-2-4 output with
+ * k = 00 01 02 ...
+ * and
+ * in = (empty string)
+ * in = 00 (1 byte)
+ * in = 00 01 (2 bytes)
+ * in = 00 01 02 (3 bytes)
+ * ...
+ * in = 00 01 02 ... 3e (63 bytes)
+ */
+static int sip24_valid(void) {
+	static const unsigned char vectors[64][8] = {
+		{ 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, },
+		{ 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, },
+		{ 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, },
+		{ 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, },
+		{ 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, },
+		{ 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, },
+		{ 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, },
+		{ 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, },
+		{ 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, },
+		{ 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, },
+		{ 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, },
+		{ 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, },
+		{ 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, },
+		{ 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, },
+		{ 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, },
+		{ 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, },
+		{ 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, },
+		{ 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, },
+		{ 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, },
+		{ 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, },
+		{ 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, },
+		{ 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, },
+		{ 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, },
+		{ 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, },
+		{ 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, },
+		{ 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, },
+		{ 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, },
+		{ 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, },
+		{ 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, },
+		{ 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, },
+		{ 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, },
+		{ 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, },
+		{ 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, },
+		{ 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, },
+		{ 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, },
+		{ 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, },
+		{ 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, },
+		{ 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, },
+		{ 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, },
+		{ 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, },
+		{ 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, },
+		{ 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, },
+		{ 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, },
+		{ 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, },
+		{ 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, },
+		{ 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, },
+		{ 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, },
+		{ 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, },
+		{ 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, },
+		{ 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, },
+		{ 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, },
+		{ 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, },
+		{ 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, },
+		{ 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, },
+		{ 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, },
+		{ 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, },
+		{ 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, },
+		{ 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, },
+		{ 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, },
+		{ 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, },
+		{ 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, },
+		{ 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, },
+		{ 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, },
+		{ 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, }
+	};
+	unsigned char in[64];
+	struct sipkey k;
+	size_t i;
+
+	sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017");
+
+	for (i = 0; i < sizeof in; ++i) {
+		in[i] = i;
+
+		if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
+			return 0;
+	}
+
+	return 1;
+} /* sip24_valid() */
+
+
+#if SIPHASH_MAIN
+
+#include <stdio.h>
+
+int main(void) {
+	int ok = sip24_valid();
+
+	if (ok)
+		puts("OK");
+	else
+		puts("FAIL");
+
+	return !ok;
+} /* main() */
+
+#endif /* SIPHASH_MAIN */
+
+
+#endif /* SIPHASH_H */