diff --git a/echo.c b/echo.c
index 3261c4f..9dea46a 100644
--- a/echo.c
+++ b/echo.c
@@ -69,8 +69,14 @@ echo_msg_init(void)
 static void
 echo_msg_add_fp(struct echo_msg *msg, time_t timestamp)
 {
+    md_ctx ctx;
+
     msg->fp.timestamp = timestamp;
-    /* digest not implemented */
+    if (md_init(&ctx, CALG_SHA1) != 0)
+        return;
+    md_update(&ctx, (BYTE*) msg->text, msg->txtlen*sizeof(msg->text[0]));
+    md_update(&ctx, (BYTE*) msg->title, wcslen(msg->title)*sizeof(msg->title[0]));
+    md_final(&ctx, msg->fp.digest);
     return;
 }
 
diff --git a/misc.c b/misc.c
index 8597f1e..0d31d4e 100644
--- a/misc.c
+++ b/misc.c
@@ -520,3 +520,53 @@ url_decode(const char *src)
 
     return out;
 }
+
+DWORD
+md_init(md_ctx *ctx, ALG_ID hash_type)
+{
+    DWORD status = 0;
+
+    if (!CryptAcquireContext(&ctx->prov, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
+        goto err;
+    if (!CryptCreateHash(ctx->prov, hash_type, 0, 0, &ctx->hash))
+    {
+        CryptReleaseContext(ctx->prov, 0);
+        goto err;
+    }
+
+    return status;
+
+err:
+    status = GetLastError();
+    MsgToEventLog(EVENTLOG_ERROR_TYPE, L"Error in md_ctx_init: status = %lu", status);
+    return status;
+}
+
+DWORD
+md_update(md_ctx *ctx, const BYTE *data, size_t size)
+{
+    DWORD status = 0;
+
+    if (!CryptHashData(ctx->hash, data, (DWORD)size, 0))
+    {
+        status = GetLastError();
+        MsgToEventLog(EVENTLOG_ERROR_TYPE, L"Error in md_update: status = %lu", status);
+    }
+    return status;
+}
+
+DWORD
+md_final(md_ctx *ctx, BYTE *md)
+{
+    DWORD status = 0;
+
+    DWORD digest_len = HASHLEN;
+    if (!CryptGetHashParam(ctx->hash, HP_HASHVAL, md, &digest_len, 0))
+    {
+        status = GetLastError();
+        MsgToEventLog(EVENTLOG_ERROR_TYPE, L"Error in md_final: status = %lu", status);
+    }
+    CryptDestroyHash(ctx->hash);
+    CryptReleaseContext(ctx->prov, 0);
+    return status;
+}
diff --git a/misc.h b/misc.h
index cbf0a24..6e9f7b6 100644
--- a/misc.h
+++ b/misc.h
@@ -22,6 +22,8 @@
 #ifndef MISC_H
 #define MISC_H
 
+#include <wincrypt.h>
+
 BOOL ManagementCommandFromInput(connection_t *, LPCSTR, HWND, int);
 BOOL ManagementCommandFromInputBase64(connection_t *, LPCSTR, HWND, int, int);
 
@@ -53,4 +55,14 @@ void CloseHandleEx(LPHANDLE h);
  */
 char *url_decode(const char *src);
 
+/* digest functions */
+typedef struct md_ctx {
+     HCRYPTPROV prov;
+     HCRYPTHASH hash;
+} md_ctx;
+
+DWORD md_init(md_ctx *ctx, ALG_ID hash_type);
+DWORD md_update(md_ctx *ctx, const BYTE *data, size_t size);
+DWORD md_final(md_ctx *ctx, BYTE *md);
+
 #endif