Index: fusl/src/crypt/crypt_sha256.c |
diff --git a/fusl/src/crypt/crypt_sha256.c b/fusl/src/crypt/crypt_sha256.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..d5f0b786df252fae553271f276f61ed8c7f9e87d |
--- /dev/null |
+++ b/fusl/src/crypt/crypt_sha256.c |
@@ -0,0 +1,322 @@ |
+/* |
+ * public domain sha256 crypt implementation |
+ * |
+ * original sha crypt design: http://people.redhat.com/drepper/SHA-crypt.txt |
+ * in this implementation at least 32bit int is assumed, |
+ * key length is limited, the $5$ prefix is mandatory, '\n' and ':' is rejected |
+ * in the salt and rounds= setting must contain a valid iteration count, |
+ * on error "*" is returned. |
+ */ |
+#include <ctype.h> |
+#include <stdlib.h> |
+#include <stdio.h> |
+#include <string.h> |
+#include <stdint.h> |
+ |
+/* public domain sha256 implementation based on fips180-3 */ |
+ |
+struct sha256 { |
+ uint64_t len; /* processed message length */ |
+ uint32_t h[8]; /* hash state */ |
+ uint8_t buf[64]; /* message block buffer */ |
+}; |
+ |
+static uint32_t ror(uint32_t n, int k) { return (n >> k) | (n << (32-k)); } |
+#define Ch(x,y,z) (z ^ (x & (y ^ z))) |
+#define Maj(x,y,z) ((x & y) | (z & (x | y))) |
+#define S0(x) (ror(x,2) ^ ror(x,13) ^ ror(x,22)) |
+#define S1(x) (ror(x,6) ^ ror(x,11) ^ ror(x,25)) |
+#define R0(x) (ror(x,7) ^ ror(x,18) ^ (x>>3)) |
+#define R1(x) (ror(x,17) ^ ror(x,19) ^ (x>>10)) |
+ |
+static const uint32_t K[64] = { |
+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 |
+}; |
+ |
+static void processblock(struct sha256 *s, const uint8_t *buf) |
+{ |
+ uint32_t W[64], t1, t2, a, b, c, d, e, f, g, h; |
+ int i; |
+ |
+ for (i = 0; i < 16; i++) { |
+ W[i] = (uint32_t)buf[4*i]<<24; |
+ W[i] |= (uint32_t)buf[4*i+1]<<16; |
+ W[i] |= (uint32_t)buf[4*i+2]<<8; |
+ W[i] |= buf[4*i+3]; |
+ } |
+ for (; i < 64; i++) |
+ W[i] = R1(W[i-2]) + W[i-7] + R0(W[i-15]) + W[i-16]; |
+ a = s->h[0]; |
+ b = s->h[1]; |
+ c = s->h[2]; |
+ d = s->h[3]; |
+ e = s->h[4]; |
+ f = s->h[5]; |
+ g = s->h[6]; |
+ h = s->h[7]; |
+ for (i = 0; i < 64; i++) { |
+ t1 = h + S1(e) + Ch(e,f,g) + K[i] + W[i]; |
+ t2 = S0(a) + Maj(a,b,c); |
+ h = g; |
+ g = f; |
+ f = e; |
+ e = d + t1; |
+ d = c; |
+ c = b; |
+ b = a; |
+ a = t1 + t2; |
+ } |
+ s->h[0] += a; |
+ s->h[1] += b; |
+ s->h[2] += c; |
+ s->h[3] += d; |
+ s->h[4] += e; |
+ s->h[5] += f; |
+ s->h[6] += g; |
+ s->h[7] += h; |
+} |
+ |
+static void pad(struct sha256 *s) |
+{ |
+ unsigned r = s->len % 64; |
+ |
+ s->buf[r++] = 0x80; |
+ if (r > 56) { |
+ memset(s->buf + r, 0, 64 - r); |
+ r = 0; |
+ processblock(s, s->buf); |
+ } |
+ memset(s->buf + r, 0, 56 - r); |
+ s->len *= 8; |
+ s->buf[56] = s->len >> 56; |
+ s->buf[57] = s->len >> 48; |
+ s->buf[58] = s->len >> 40; |
+ s->buf[59] = s->len >> 32; |
+ s->buf[60] = s->len >> 24; |
+ s->buf[61] = s->len >> 16; |
+ s->buf[62] = s->len >> 8; |
+ s->buf[63] = s->len; |
+ processblock(s, s->buf); |
+} |
+ |
+static void sha256_init(struct sha256 *s) |
+{ |
+ s->len = 0; |
+ s->h[0] = 0x6a09e667; |
+ s->h[1] = 0xbb67ae85; |
+ s->h[2] = 0x3c6ef372; |
+ s->h[3] = 0xa54ff53a; |
+ s->h[4] = 0x510e527f; |
+ s->h[5] = 0x9b05688c; |
+ s->h[6] = 0x1f83d9ab; |
+ s->h[7] = 0x5be0cd19; |
+} |
+ |
+static void sha256_sum(struct sha256 *s, uint8_t *md) |
+{ |
+ int i; |
+ |
+ pad(s); |
+ for (i = 0; i < 8; i++) { |
+ md[4*i] = s->h[i] >> 24; |
+ md[4*i+1] = s->h[i] >> 16; |
+ md[4*i+2] = s->h[i] >> 8; |
+ md[4*i+3] = s->h[i]; |
+ } |
+} |
+ |
+static void sha256_update(struct sha256 *s, const void *m, unsigned long len) |
+{ |
+ const uint8_t *p = m; |
+ unsigned r = s->len % 64; |
+ |
+ s->len += len; |
+ if (r) { |
+ if (len < 64 - r) { |
+ memcpy(s->buf + r, p, len); |
+ return; |
+ } |
+ memcpy(s->buf + r, p, 64 - r); |
+ len -= 64 - r; |
+ p += 64 - r; |
+ processblock(s, s->buf); |
+ } |
+ for (; len >= 64; len -= 64, p += 64) |
+ processblock(s, p); |
+ memcpy(s->buf, p, len); |
+} |
+ |
+static const unsigned char b64[] = |
+"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; |
+ |
+static char *to64(char *s, unsigned int u, int n) |
+{ |
+ while (--n >= 0) { |
+ *s++ = b64[u % 64]; |
+ u /= 64; |
+ } |
+ return s; |
+} |
+ |
+/* key limit is not part of the original design, added for DoS protection. |
+ * rounds limit has been lowered (versus the reference/spec), also for DoS |
+ * protection. runtime is O(klen^2 + klen*rounds) */ |
+#define KEY_MAX 256 |
+#define SALT_MAX 16 |
+#define ROUNDS_DEFAULT 5000 |
+#define ROUNDS_MIN 1000 |
+#define ROUNDS_MAX 9999999 |
+ |
+/* hash n bytes of the repeated md message digest */ |
+static void hashmd(struct sha256 *s, unsigned int n, const void *md) |
+{ |
+ unsigned int i; |
+ |
+ for (i = n; i > 32; i -= 32) |
+ sha256_update(s, md, 32); |
+ sha256_update(s, md, i); |
+} |
+ |
+static char *sha256crypt(const char *key, const char *setting, char *output) |
+{ |
+ struct sha256 ctx; |
+ unsigned char md[32], kmd[32], smd[32]; |
+ unsigned int i, r, klen, slen; |
+ char rounds[20] = ""; |
+ const char *salt; |
+ char *p; |
+ |
+ /* reject large keys */ |
+ klen = strnlen(key, KEY_MAX+1); |
+ if (klen > KEY_MAX) |
+ return 0; |
+ |
+ /* setting: $5$rounds=n$salt$ (rounds=n$ and closing $ are optional) */ |
+ if (strncmp(setting, "$5$", 3) != 0) |
+ return 0; |
+ salt = setting + 3; |
+ |
+ r = ROUNDS_DEFAULT; |
+ if (strncmp(salt, "rounds=", sizeof "rounds=" - 1) == 0) { |
+ unsigned long u; |
+ char *end; |
+ |
+ /* |
+ * this is a deviation from the reference: |
+ * bad rounds setting is rejected if it is |
+ * - empty |
+ * - unterminated (missing '$') |
+ * - begins with anything but a decimal digit |
+ * the reference implementation treats these bad |
+ * rounds as part of the salt or parse them with |
+ * strtoul semantics which may cause problems |
+ * including non-portable hashes that depend on |
+ * the host's value of ULONG_MAX. |
+ */ |
+ salt += sizeof "rounds=" - 1; |
+ if (!isdigit(*salt)) |
+ return 0; |
+ u = strtoul(salt, &end, 10); |
+ if (*end != '$') |
+ return 0; |
+ salt = end+1; |
+ if (u < ROUNDS_MIN) |
+ r = ROUNDS_MIN; |
+ else if (u > ROUNDS_MAX) |
+ r = ROUNDS_MAX; |
+ else |
+ r = u; |
+ /* needed when rounds is zero prefixed or out of bounds */ |
+ sprintf(rounds, "rounds=%u$", r); |
+ } |
+ |
+ for (i = 0; i < SALT_MAX && salt[i] && salt[i] != '$'; i++) |
+ /* reject characters that interfere with /etc/shadow parsing */ |
+ if (salt[i] == '\n' || salt[i] == ':') |
+ return 0; |
+ slen = i; |
+ |
+ /* B = sha(key salt key) */ |
+ sha256_init(&ctx); |
+ sha256_update(&ctx, key, klen); |
+ sha256_update(&ctx, salt, slen); |
+ sha256_update(&ctx, key, klen); |
+ sha256_sum(&ctx, md); |
+ |
+ /* A = sha(key salt repeat-B alternate-B-key) */ |
+ sha256_init(&ctx); |
+ sha256_update(&ctx, key, klen); |
+ sha256_update(&ctx, salt, slen); |
+ hashmd(&ctx, klen, md); |
+ for (i = klen; i > 0; i >>= 1) |
+ if (i & 1) |
+ sha256_update(&ctx, md, sizeof md); |
+ else |
+ sha256_update(&ctx, key, klen); |
+ sha256_sum(&ctx, md); |
+ |
+ /* DP = sha(repeat-key), this step takes O(klen^2) time */ |
+ sha256_init(&ctx); |
+ for (i = 0; i < klen; i++) |
+ sha256_update(&ctx, key, klen); |
+ sha256_sum(&ctx, kmd); |
+ |
+ /* DS = sha(repeat-salt) */ |
+ sha256_init(&ctx); |
+ for (i = 0; i < 16 + md[0]; i++) |
+ sha256_update(&ctx, salt, slen); |
+ sha256_sum(&ctx, smd); |
+ |
+ /* iterate A = f(A,DP,DS), this step takes O(rounds*klen) time */ |
+ for (i = 0; i < r; i++) { |
+ sha256_init(&ctx); |
+ if (i % 2) |
+ hashmd(&ctx, klen, kmd); |
+ else |
+ sha256_update(&ctx, md, sizeof md); |
+ if (i % 3) |
+ sha256_update(&ctx, smd, slen); |
+ if (i % 7) |
+ hashmd(&ctx, klen, kmd); |
+ if (i % 2) |
+ sha256_update(&ctx, md, sizeof md); |
+ else |
+ hashmd(&ctx, klen, kmd); |
+ sha256_sum(&ctx, md); |
+ } |
+ |
+ /* output is $5$rounds=n$salt$hash */ |
+ p = output; |
+ p += sprintf(p, "$5$%s%.*s$", rounds, slen, salt); |
+ static const unsigned char perm[][3] = { |
+ 0,10,20,21,1,11,12,22,2,3,13,23,24,4,14, |
+ 15,25,5,6,16,26,27,7,17,18,28,8,9,19,29 }; |
+ for (i=0; i<10; i++) p = to64(p, |
+ (md[perm[i][0]]<<16)|(md[perm[i][1]]<<8)|md[perm[i][2]], 4); |
+ p = to64(p, (md[31]<<8)|md[30], 3); |
+ *p = 0; |
+ return output; |
+} |
+ |
+char *__crypt_sha256(const char *key, const char *setting, char *output) |
+{ |
+ static const char testkey[] = "Xy01@#\x01\x02\x80\x7f\xff\r\n\x81\t !"; |
+ static const char testsetting[] = "$5$rounds=1234$abc0123456789$"; |
+ static const char testhash[] = "$5$rounds=1234$abc0123456789$3VfDjPt05VHFn47C/ojFZ6KRPYrOjj1lLbH.dkF3bZ6"; |
+ char testbuf[128]; |
+ char *p, *q; |
+ |
+ p = sha256crypt(key, setting, output); |
+ /* self test and stack cleanup */ |
+ q = sha256crypt(testkey, testsetting, testbuf); |
+ if (!p || q != testbuf || memcmp(testbuf, testhash, sizeof testhash)) |
+ return "*"; |
+ return p; |
+} |