diff --git a/configure.in b/configure.in

index de6a8ad..4ca489d 100644

--- a/configure.in

+++ b/configure.in

@@ -465,6 +465,28 @@ LIBS=""

 AC_SEARCH_LIBS(crypt, crypt)

 CRYPT_LIBS="$LIBS"

 APACHE_SUBST(CRYPT_LIBS)

+

+if test "$ac_cv_search_crypt" != "no"; then

+   # Test crypt() with the SHA-512 test vector from https://akkadia.org/drepper/SHA-crypt.txt

+   AC_CACHE_CHECK([whether crypt() supports SHA-2], [ap_cv_crypt_sha2], [

+    AC_RUN_IFELSE([AC_LANG_PROGRAM([[

+#include <crypt.h>

+#include <stdlib.h>

+#include <string.h>

+

+#define PASSWD_0 "Hello world!"

+#define SALT_0 "\$6\$saltstring"

+#define EXPECT_0 "\$6\$saltstring\$svn8UoSVapNtMuq1ukKS4tPQd8iKwSMHWjl/O817G3uBnIFNjnQJu" \

+               "esI68u4OTLiBFdcbYEdFCoEOfaS35inz1"

+]], [char *result = crypt(PASSWD_0, SALT_0);

+     if (!result) return 1;

+     if (strcmp(result, EXPECT_0)) return 2;

+])], [ap_cv_crypt_sha2=yes], [ap_cv_crypt_sha2=no])])

+   if test "$ap_cv_crypt_sha2" = yes; then

+     AC_DEFINE([HAVE_CRYPT_SHA2], 1, [Define if crypt() supports SHA-2 hashes])

+   fi

+fi

+

 LIBS="$saved_LIBS"

 dnl See Comment #Spoon

diff --git a/support/htpasswd.c b/support/htpasswd.c

index 660a27c..136f62a 100644

--- a/support/htpasswd.c

+++ b/support/htpasswd.c

@@ -98,28 +98,32 @@ static int mkrecord(struct passwd_ctx *ctx, char *user)

 static void usage(void)

 {

     apr_file_printf(errfile, "Usage:" NL

-        "\thtpasswd [-cimBdpsDv] [-C cost] passwordfile username" NL

-        "\thtpasswd -b[cmBdpsDv] [-C cost] passwordfile username password" NL

+        "\thtpasswd [-cimB25dpsDv] [-C cost] [-r rounds] passwordfile username" NL

+        "\thtpasswd -b[cmB25dpsDv] [-C cost] [-r rounds] passwordfile username password" NL

         NL

-        "\thtpasswd -n[imBdps] [-C cost] username" NL

-        "\thtpasswd -nb[mBdps] [-C cost] username password" NL

+        "\thtpasswd -n[imB25dps] [-C cost] [-r rounds] username" NL

+        "\thtpasswd -nb[mB25dps] [-C cost] [-r rounds] username password" NL

         " -c  Create a new file." NL

         " -n  Don't update file; display results on stdout." NL

         " -b  Use the password from the command line rather than prompting "

             "for it." NL

         " -i  Read password from stdin without verification (for script usage)." NL

         " -m  Force MD5 encryption of the password (default)." NL

-        " -B  Force bcrypt encryption of the password (very secure)." NL

+        " -2  Force SHA-256 crypt() hash of the password (secure)." NL

+        " -5  Force SHA-512 crypt() hash of the password (secure)." NL

+        " -B  Force bcrypt encryption of the password (very secure)." NL

         " -C  Set the computing time used for the bcrypt algorithm" NL

         "     (higher is more secure but slower, default: %d, valid: 4 to 31)." NL

+        " -r  Set the number of rounds used for the SHA-256, SHA-512 algorithms" NL

+        "     (higher is more secure but slower, default: 5000)." NL

         " -d  Force CRYPT encryption of the password (8 chars max, insecure)." NL

-        " -s  Force SHA encryption of the password (insecure)." NL

+        " -s  Force SHA-1 encryption of the password (insecure)." NL

         " -p  Do not encrypt the password (plaintext, insecure)." NL

         " -D  Delete the specified user." NL

         " -v  Verify password for the specified user." NL

         "On other systems than Windows and NetWare the '-p' flag will "

             "probably not work." NL

-        "The SHA algorithm does not use a salt and is less secure than the "

+        "The SHA-1 algorithm does not use a salt and is less secure than the "

             "MD5 algorithm." NL,

         BCRYPT_DEFAULT_COST

     );

@@ -178,7 +182,7 @@ static void check_args(int argc, const char *const argv[],

     if (rv != APR_SUCCESS)

         exit(ERR_SYNTAX);

-    while ((rv = apr_getopt(state, "cnmspdBbDiC:v", &opt, &opt_arg)) == APR_SUCCESS) {

+    while ((rv = apr_getopt(state, "cnmspdBbDi25C:r:v", &opt, &opt_arg)) == APR_SUCCESS) {

         switch (opt) {

         case 'c':

             *mask |= APHTP_NEWFILE;

diff --git a/support/passwd_common.c b/support/passwd_common.c

index 664e509..d45657c 100644

--- a/support/passwd_common.c

+++ b/support/passwd_common.c

@@ -185,10 +185,15 @@ int mkhash(struct passwd_ctx *ctx)

 #if CRYPT_ALGO_SUPPORTED

     char *cbuf;

 #endif

+#ifdef HAVE_CRYPT_SHA2

+    const char *setting;

+    char method;

+#endif

-    if (ctx->cost != 0 && ctx->alg != ALG_BCRYPT) {

+    if (ctx->cost != 0 && ctx->alg != ALG_BCRYPT

+        && ctx->alg != ALG_CRYPT_SHA256 && ctx->alg != ALG_CRYPT_SHA512 ) {

         apr_file_printf(errfile,

-                        "Warning: Ignoring -C argument for this algorithm." NL);

+                        "Warning: Ignoring -C/-r argument for this algorithm." NL);

     }

     if (ctx->passwd == NULL) {

@@ -246,6 +251,34 @@ int mkhash(struct passwd_ctx *ctx)

         break;

 #endif /* CRYPT_ALGO_SUPPORTED */

+#ifdef HAVE_CRYPT_SHA2

+    case ALG_CRYPT_SHA256:

+    case ALG_CRYPT_SHA512:

+        ret = generate_salt(salt, 16, &ctx->errstr, ctx->pool);

+        if (ret != 0)

+            break;

+

+        method = ctx->alg == ALG_CRYPT_SHA256 ? '5': '6';

+

+        if (ctx->cost) 

+            setting = apr_psprintf(ctx->pool, "$%c$rounds=%d$%s",

+                                   method, ctx->cost, salt);

+        else

+            setting = apr_psprintf(ctx->pool, "$%c$%s",

+                                   method, salt);

+

+        cbuf = crypt(pw, setting);

+        if (cbuf == NULL) {

+            rv = APR_FROM_OS_ERROR(errno);

+            ctx->errstr = apr_psprintf(ctx->pool, "crypt() failed: %pm", &rv;;

+            ret = ERR_PWMISMATCH;

+            break;

+        }

+

+        apr_cpystrn(ctx->out, cbuf, ctx->out_len - 1);

+        break;

+#endif /* HAVE_CRYPT_SHA2 */

+

 #if BCRYPT_ALGO_SUPPORTED

     case ALG_BCRYPT:

         rv = apr_generate_random_bytes((unsigned char*)salt, 16);

@@ -294,6 +327,19 @@ int parse_common_options(struct passwd_ctx *ctx, char opt,

     case 's':

         ctx->alg = ALG_APSHA;

         break;

+#ifdef HAVE_CRYPT_SHA2

+    case '2':

+        ctx->alg = ALG_CRYPT_SHA256;

+        break;

+    case '5':

+        ctx->alg = ALG_CRYPT_SHA512;

+        break;

+#else

+    case '2':

+    case '5':

+        ctx->errstr = "SHA-2 crypt() algorithms are not supported on this platform.";

+        return ERR_ALG_NOT_SUPP;

+#endif

     case 'p':

         ctx->alg = ALG_PLAIN;

 #if !PLAIN_ALGO_SUPPORTED

@@ -324,11 +370,12 @@ int parse_common_options(struct passwd_ctx *ctx, char opt,

         return ERR_ALG_NOT_SUPP;

 #endif

         break;

-    case 'C': {

+    case 'C':

+    case 'r': {

             char *endptr;

             long num = strtol(opt_arg, &endptr, 10);

             if (*endptr != '\0' || num <= 0) {

-                ctx->errstr = "argument to -C must be a positive integer";

+                ctx->errstr = "argument to -C/-r must be a positive integer";

                 return ERR_SYNTAX;

             }

             ctx->cost = num;

diff --git a/support/passwd_common.h b/support/passwd_common.h

index 660081e..f1b3cd7 100644

--- a/support/passwd_common.h

+++ b/support/passwd_common.h

@@ -28,6 +28,8 @@

 #include "apu_version.h"

 #endif

+#include "ap_config_auto.h"

+

 #define MAX_STRING_LEN 256

 #define ALG_PLAIN 0

@@ -35,6 +37,8 @@

 #define ALG_APMD5 2

 #define ALG_APSHA 3

 #define ALG_BCRYPT 4

+#define ALG_CRYPT_SHA256 5

+#define ALG_CRYPT_SHA512 6

 #define BCRYPT_DEFAULT_COST 5

@@ -84,7 +88,7 @@ struct passwd_ctx {

     apr_size_t      out_len;

     char            *passwd;

     int             alg;

-    int             cost;

+    int             cost; /* cost for bcrypt, rounds for SHA-2 */

     enum {

         PW_PROMPT = 0,

         PW_ARG,