--- /dev/null
+/* SPDX-License-Identifier: LicenseRef-alg-sha1-public-domain */
+
+/*
+SHA-1 in C
+By Steve Reid <sreid@sea-to-sky.net>
+100% Public Domain
+
+-----------------
+Modified 7/98
+By James H. Brown <jbrown@burgoyne.com>
+Still 100% Public Domain
+
+Corrected a problem which generated improper hash values on 16 bit machines
+Routine SHA1Update changed from
+ void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int len)
+to
+ void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned long len)
+
+The 'len' parameter was declared an int which works fine on 32 bit machines.
+However, on 16 bit machines an int is too small for the shifts being done
+against
+it. This caused the hash function to generate incorrect values if len was
+greater than 8191 (8K - 1) due to the 'len << 3' on line 3 of SHA1Update().
+
+Since the file IO in main() reads 16K at a time, any file 8K or larger would
+be guaranteed to generate the wrong hash (e.g. Test Vector #3,
+a million "a"s).
+
+I also changed the declaration of variables i & j in SHA1Update to
+unsigned long from unsigned int for the same reason.
+
+These changes should make no difference to any 32 bit implementations since
+an int and a long are the same size in those environments.
+
+--
+I also corrected a few compiler warnings generated by Borland C.
+1. Added #include <process.h> for exit() prototype
+2. Removed unused variable 'j' in SHA1Final
+3. Changed exit(0) to return(0) at end of main.
+
+ALL changes I made can be located by searching for comments containing 'JHB'
+-----------------
+Modified 8/98
+By Steve Reid <sreid@sea-to-sky.net>
+Still 100% public domain
+
+1- Removed #include <process.h> and used return() instead of exit()
+2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall)
+3- Changed email address from steve@edmweb.com to sreid@sea-to-sky.net
+
+-----------------
+Modified 4/01
+By Saul Kravitz <Saul.Kravitz@celera.com>
+Still 100% PD
+Modified to run on Compaq Alpha hardware.
+
+-----------------
+Modified 07/2002
+By Ralph Giles <giles@ghostscript.com>
+Still 100% public domain
+modified for use with stdint types, autoconf
+code cleanup, removed attribution comments
+switched SHA1Final() argument order for consistency
+use SHA1_ prefix for public api
+move public api to sha1.h
+
+-----------------
+Modified 10/2017
+By Björn Esser <besser82@fedoraproject.org>
+Still 100% public domain
+modified for use with libxcrypt
+
+Modified 09/2024
+By anonymix007 <48598263+anonymix007@users.noreply.github.com>
+Still 100% public domain
+modified for use with systemd
+*/
+
+#include "memory-util-fundamental.h"
+#include "sha1-fundamental.h"
+
+#define SHA1_DIGEST_SIZE 20
+
+#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
+
+/* blk0() and blk() perform the initial expand. */
+/* I got the idea of expanding during the round function from SSLeay */
+/* FIXME: can we do this in an endian-proof way? */
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+# define blk0(i) block.l[i]
+#else
+# define blk0(i) (block.l[i] = (rol(block.l[i], 24) & 0xFF00FF00) | (rol(block.l[i], 8) & 0x00FF00FF))
+#endif
+#define blk(i) \
+ (block.l[i & 15] = rol( \
+ block.l[(i + 13) & 15] ^ block.l[(i + 8) & 15] ^ block.l[(i + 2) & 15] ^ \
+ block.l[i & 15], \
+ 1))
+
+/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
+#define R0(v, w, x, y, z, i) \
+ z += ((w & (x ^ y)) ^ y) + blk0(i) + 0x5A827999 + rol(v, 5); \
+ w = rol(w, 30);
+#define R1(v, w, x, y, z, i) \
+ z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
+ w = rol(w, 30);
+#define R2(v, w, x, y, z, i) \
+ z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); \
+ w = rol(w, 30);
+#define R3(v, w, x, y, z, i) \
+ z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
+ w = rol(w, 30);
+#define R4(v, w, x, y, z, i) \
+ z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
+ w = rol(w, 30);
+
+/* Hash a single 512-bit block. This is the core of the algorithm. */
+static void sha1_do_transform(uint32_t state[5], const uint8_t buffer[64]) {
+ uint32_t a, b, c, d, e;
+ typedef union {
+ uint8_t c[64];
+ uint32_t l[16];
+ } CHAR64LONG16;
+ CHAR64LONG16 block;
+
+ memcpy(&block, buffer, 64);
+
+ /* Copy context->state[] to working vars */
+ a = state[0];
+ b = state[1];
+ c = state[2];
+ d = state[3];
+ e = state[4];
+
+ /* 4 rounds of 20 operations each. Loop unrolled. */
+ R0(a, b, c, d, e, 0);
+ R0(e, a, b, c, d, 1);
+ R0(d, e, a, b, c, 2);
+ R0(c, d, e, a, b, 3);
+ R0(b, c, d, e, a, 4);
+ R0(a, b, c, d, e, 5);
+ R0(e, a, b, c, d, 6);
+ R0(d, e, a, b, c, 7);
+ R0(c, d, e, a, b, 8);
+ R0(b, c, d, e, a, 9);
+ R0(a, b, c, d, e, 10);
+ R0(e, a, b, c, d, 11);
+ R0(d, e, a, b, c, 12);
+ R0(c, d, e, a, b, 13);
+ R0(b, c, d, e, a, 14);
+ R0(a, b, c, d, e, 15);
+ R1(e, a, b, c, d, 16);
+ R1(d, e, a, b, c, 17);
+ R1(c, d, e, a, b, 18);
+ R1(b, c, d, e, a, 19);
+ R2(a, b, c, d, e, 20);
+ R2(e, a, b, c, d, 21);
+ R2(d, e, a, b, c, 22);
+ R2(c, d, e, a, b, 23);
+ R2(b, c, d, e, a, 24);
+ R2(a, b, c, d, e, 25);
+ R2(e, a, b, c, d, 26);
+ R2(d, e, a, b, c, 27);
+ R2(c, d, e, a, b, 28);
+ R2(b, c, d, e, a, 29);
+ R2(a, b, c, d, e, 30);
+ R2(e, a, b, c, d, 31);
+ R2(d, e, a, b, c, 32);
+ R2(c, d, e, a, b, 33);
+ R2(b, c, d, e, a, 34);
+ R2(a, b, c, d, e, 35);
+ R2(e, a, b, c, d, 36);
+ R2(d, e, a, b, c, 37);
+ R2(c, d, e, a, b, 38);
+ R2(b, c, d, e, a, 39);
+ R3(a, b, c, d, e, 40);
+ R3(e, a, b, c, d, 41);
+ R3(d, e, a, b, c, 42);
+ R3(c, d, e, a, b, 43);
+ R3(b, c, d, e, a, 44);
+ R3(a, b, c, d, e, 45);
+ R3(e, a, b, c, d, 46);
+ R3(d, e, a, b, c, 47);
+ R3(c, d, e, a, b, 48);
+ R3(b, c, d, e, a, 49);
+ R3(a, b, c, d, e, 50);
+ R3(e, a, b, c, d, 51);
+ R3(d, e, a, b, c, 52);
+ R3(c, d, e, a, b, 53);
+ R3(b, c, d, e, a, 54);
+ R3(a, b, c, d, e, 55);
+ R3(e, a, b, c, d, 56);
+ R3(d, e, a, b, c, 57);
+ R3(c, d, e, a, b, 58);
+ R3(b, c, d, e, a, 59);
+ R4(a, b, c, d, e, 60);
+ R4(e, a, b, c, d, 61);
+ R4(d, e, a, b, c, 62);
+ R4(c, d, e, a, b, 63);
+ R4(b, c, d, e, a, 64);
+ R4(a, b, c, d, e, 65);
+ R4(e, a, b, c, d, 66);
+ R4(d, e, a, b, c, 67);
+ R4(c, d, e, a, b, 68);
+ R4(b, c, d, e, a, 69);
+ R4(a, b, c, d, e, 70);
+ R4(e, a, b, c, d, 71);
+ R4(d, e, a, b, c, 72);
+ R4(c, d, e, a, b, 73);
+ R4(b, c, d, e, a, 74);
+ R4(a, b, c, d, e, 75);
+ R4(e, a, b, c, d, 76);
+ R4(d, e, a, b, c, 77);
+ R4(c, d, e, a, b, 78);
+ R4(b, c, d, e, a, 79);
+
+ /* Add the working vars back into context.state[] */
+ state[0] += a;
+ state[1] += b;
+ state[2] += c;
+ state[3] += d;
+ state[4] += e;
+
+ /* Wipe variables */
+ a = b = c = d = e = 0;
+}
+
+/* SHA1Init - Initialize new context */
+void sha1_init_ctx(struct sha1_ctx *ctx) {
+ /* SHA1 initialization constants */
+ ctx->state[0] = 0x67452301;
+ ctx->state[1] = 0xEFCDAB89;
+ ctx->state[2] = 0x98BADCFE;
+ ctx->state[3] = 0x10325476;
+ ctx->state[4] = 0xC3D2E1F0;
+ ctx->count[0] = ctx->count[1] = 0;
+}
+
+/* Run your data through this. */
+void sha1_process_bytes(const void *buffer, size_t size, struct sha1_ctx *ctx) {
+ size_t i, j;
+
+ j = (ctx->count[0] >> 3) & 63;
+ if ((ctx->count[0] += (uint32_t) size << 3) < ((uint32_t) size << 3))
+ ctx->count[1]++;
+ ctx->count[1] += (uint32_t) (size >> 29);
+ if ((j + size) > 63) {
+ memcpy(&ctx->buffer[j], buffer, (i = 64 - j));
+ sha1_do_transform(ctx->state, ctx->buffer);
+ DISABLE_WARNING_STRINGOP_OVERREAD;
+ for (; i + 63 < size; i += 64)
+ sha1_do_transform(ctx->state, (const uint8_t *) buffer + i);
+ REENABLE_WARNING;
+ j = 0;
+ } else
+ i = 0;
+ memcpy(&ctx->buffer[j], (const uint8_t *) buffer + i, size - i);
+}
+
+/* Add padding and return the message digest. */
+void *sha1_finish_ctx(struct sha1_ctx *ctx, uint8_t result[static SHA1_DIGEST_SIZE]) {
+ uint32_t i;
+ uint8_t finalcount[8];
+
+ for (i = 0; i < 8; i++) {
+ finalcount[i] = (unsigned char) ((ctx->count[(i >= 4 ? 0 : 1)] >> ((3 - (i & 3)) * 8)) &
+ 255); /* Endian independent */
+ }
+ sha1_process_bytes((const uint8_t *) "\200", 1, ctx);
+ while ((ctx->count[0] & 504) != 448)
+ sha1_process_bytes((const uint8_t *) "\0", 1, ctx);
+ sha1_process_bytes(finalcount, 8, ctx); /* Should cause a sha1_do_transform() */
+ for (i = 0; i < SHA1_DIGEST_SIZE; i++) {
+ result[i] = (uint8_t) ((ctx->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255);
+ }
+
+ /* Wipe variables */
+ i = 0;
+ memzero(ctx, sizeof(struct sha1_ctx));
+ memzero(finalcount, 8); /* SWR */
+
+ return result;
+}