Huge overhall; fix code; remove external deps

1 files changed, 76 insertions, 0 deletions

diff --git a/src/sha1.c b/src/sha1.c
new file mode 100644
index 0000000..5759991
--- /dev/null
+++ b/src/sha1.c
@@ -0,0 +1,76 @@
+#include <err.h>
+#include <errno.h>
+#include <string.h>
+
+#include "sha1.h"
+#include "xendian.h"
+
+#define lengthof(x) (sizeof(x) / sizeof(*(x)))
+#define MIN(x, y)   ((x) < (y) ? (x) : (y))
+
+void sha1hashblk(sha1_t *, const uint8_t *);
+
+void
+sha1init(sha1_t *s)
+{
+	static const uint32_t H[] = {
+		0x67452301,
+		0xEFCDAB89,
+		0x98BADCFE,
+		0x10325476,
+		0xC3D2E1F0,
+	};
+	memcpy(s->dgst, H, sizeof(H));
+	s->msgsz = s->bufsz = 0;
+}
+
+void
+sha1hash(sha1_t *s, const uint8_t *msg, size_t msgsz)
+{
+	if (s->msgsz + (msgsz * 8) < s->msgsz) {
+		errno = EOVERFLOW;
+		err(1, "sha1");
+	}
+
+	s->msgsz += msgsz * 8;
+
+	while (msgsz != 0) {
+		size_t free_space = SHA1BLKSZ - s->bufsz;
+		size_t ncpy = MIN(msgsz, free_space);
+		memcpy(s->buf + s->bufsz, msg, ncpy);
+		s->bufsz += ncpy;
+		msg += ncpy;
+		msgsz -= ncpy;
+
+		if (s->bufsz == SHA1BLKSZ) {
+			sha1hashblk(s, s->buf);
+			s->bufsz = 0;
+		}
+	}
+}
+
+void
+sha1end(sha1_t *s, uint8_t *dgst)
+{
+	s->buf[s->bufsz++] = 0x80;
+
+	if (s->bufsz > SHA1BLKSZ - sizeof(uint64_t)) {
+		while (s->bufsz < SHA1BLKSZ)
+			s->buf[s->bufsz++] = 0;
+		sha1hashblk(s, s->buf);
+		s->bufsz = 0;
+	}
+
+	while (s->bufsz < 56)
+		s->buf[s->bufsz++] = 0;
+	uint64_t n = htobe64(s->msgsz);
+	memcpy(s->buf + (SHA1BLKSZ/8 - 1)*sizeof(uint64_t), &n, sizeof(n));
+
+	sha1hashblk(s, s->buf);
+
+	for (size_t i = 0; i < lengthof(s->dgst); i++) {
+		/* Pretty please compiler optimize this */
+		uint32_t n = htobe32(s->dgst[i]);
+		memcpy(dgst + i*sizeof(uint32_t), &n, sizeof(n));
+	}
+}