md5.c

#include "md5.h"

void MD5_Init(MD5_CTX *ctx) {
	ctx->a = 0x67452301;
	ctx->b = 0xefcdab89;
	ctx->c = 0x98badcfe;
	ctx->d = 0x10325476;

	ctx->lo = 0;
	ctx->hi = 0;
}

void MD5_Update(MD5_CTX *ctx, unsigned char *data, unsigned long size) {
	MD5_u32plus saved_lo;
	unsigned long used, free;

	saved_lo = ctx->lo;
	if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)
		ctx->hi++;
	ctx->hi += size >> 29;

	used = saved_lo & 0x3f;

	if (used) {
		free = 64 - used;

		if (size < free) {
			memcpy(&ctx->buffer[used], data, size);
			return;
		}

		memcpy(&ctx->buffer[used], data, free);
		data = (unsigned char *)data + free;
		size -= free;
		body(ctx, ctx->buffer, 64);
	}

	if (size >= 64) {
		data = (unsigned char *)body(ctx, data, size & ~(unsigned long)0x3f);
		size &= 0x3f;
	}

	memcpy(ctx->buffer, data, size);
}

void MD5_Final(unsigned char *result, MD5_CTX *ctx) {
	unsigned long used, free;

	used = ctx->lo & 0x3f;

	ctx->buffer[used++] = 0x80;

	free = 64 - used;

	if (free < 8) {
		memset(&ctx->buffer[used], 0, free);
		body(ctx, ctx->buffer, 64);
		used = 0;
		free = 64;
	}

	memset(&ctx->buffer[used], 0, free - 8);

	ctx->lo <<= 3;
	ctx->buffer[56] = ctx->lo;
	ctx->buffer[57] = ctx->lo >> 8;
	ctx->buffer[58] = ctx->lo >> 16;
	ctx->buffer[59] = ctx->lo >> 24;
	ctx->buffer[60] = ctx->hi;
	ctx->buffer[61] = ctx->hi >> 8;
	ctx->buffer[62] = ctx->hi >> 16;
	ctx->buffer[63] = ctx->hi >> 24;

	body(ctx, ctx->buffer, 64);

	result[0] = ctx->a;
	result[1] = ctx->a >> 8;
	result[2] = ctx->a >> 16;
	result[3] = ctx->a >> 24;
	result[4] = ctx->b;
	result[5] = ctx->b >> 8;
	result[6] = ctx->b >> 16;
	result[7] = ctx->b >> 24;
	result[8] = ctx->c;
	result[9] = ctx->c >> 8;
	result[10] = ctx->c >> 16;
	result[11] = ctx->c >> 24;
	result[12] = ctx->d;
	result[13] = ctx->d >> 8;
	result[14] = ctx->d >> 16;
	result[15] = ctx->d >> 24;

	memset(ctx, 0, sizeof(*ctx));
}

#ifdef __cplusplus
extern "C" {
#endif

	void md5(char *in, char *out) {
		MD5_CTX mdctx;
		char ob[17];
		int i = 0;
		char test[3];
		memset(ob, 0, 17);
		MD5_Init(&mdctx);
		MD5_Update(&mdctx, (unsigned char *)in, strlen(in));
		MD5_Final((unsigned char *)ob, &mdctx);
		memset(out, 0, 33); /* This will fail if the output buffer is too short! */
		for (i = 0; i < 16; i++) {
			sprintf(test, "%s%x", ((0x000000ff & ob[i]) < 0x10) ? "0" : "", (0x000000ff & ob[i]));
			strcat(out, test);
		}
		return;
	}
#ifdef __cplusplus
}
#endif