auth: add support for RFC7616 - HTTP Digest access authentication

Signed-off-by: Florin <petriuc.florin@gmail.com>

6 files changed, 454 insertions, 45 deletions

diff --git a/lib/Makefile.inc b/lib/Makefile.inc
index 5c0b930cf..a9de05a9c 100644
--- a/lib/Makefile.inc
+++ b/lib/Makefile.inc
@@ -54,7 +54,7 @@ LIB_CFILES = file.c timeval.c base64.c hostip.c progress.c formdata.c   \
   http_ntlm.c curl_ntlm_wb.c curl_ntlm_core.c curl_sasl.c rand.c        \
   curl_multibyte.c hostcheck.c conncache.c pipeline.c dotdot.c          \
   x509asn1.c http2.c smb.c curl_endian.c curl_des.c system_win32.c      \
-  mime.c
+  mime.c sha256.c
 
 LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   formdata.h cookie.h http.h sendf.h ftp.h url.h dict.h if2ip.h         \
@@ -73,7 +73,7 @@ LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   curl_sasl.h curl_multibyte.h hostcheck.h conncache.h                  \
   curl_setup_once.h multihandle.h setup-vms.h pipeline.h dotdot.h       \
   x509asn1.h http2.h sigpipe.h smb.h curl_endian.h curl_des.h           \
-  curl_printf.h system_win32.h rand.h mime.h
+  curl_printf.h system_win32.h rand.h mime.h curl_sha256.h
 
 LIB_RCFILES = libcurl.rc
 
diff --git a/lib/curl_sha256.h b/lib/curl_sha256.h
new file mode 100644
index 000000000..6db4b04db
--- /dev/null
+++ b/lib/curl_sha256.h
@@ -0,0 +1,32 @@
+#ifndef HEADER_CURL_SHA256_H
+#define HEADER_CURL_SHA256_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2010, Florin Petriuc, <petriuc.florin@gmail.com>
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#ifndef CURL_DISABLE_CRYPTO_AUTH
+
+void Curl_sha256it(unsigned char *outbuffer,
+                const unsigned char *input);
+
+#endif
+
+#endif /* HEADER_CURL_SHA256_H */
diff --git a/lib/sha256.c b/lib/sha256.c
new file mode 100644
index 000000000..cd81c0254
--- /dev/null
+++ b/lib/sha256.c
@@ -0,0 +1,262 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2016, Florin Petriuc, <petriuc.florin@gmail.com>
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifndef CURL_DISABLE_CRYPTO_AUTH
+
+#include "warnless.h"
+#include "curl_sha256.h"
+
+#if defined(USE_OPENSSL)
+
+/* When OpenSSL is available we use the SHA256-function from OpenSSL */
+#include <openssl/sha.h>
+
+#else
+
+/* When no other crypto library is available we use this code segment */
+
+/* ===== start - public domain SHA256 implementation ===== */
+/* This is based on SHA256 implementation in LibTomCrypt that was released into
+ * public domain by Tom St Denis. */
+
+#define WPA_GET_BE32(a) ((((unsigned long)(a)[0]) << 24) | \
+                         (((unsigned long)(a)[1]) << 16) | \
+                         (((unsigned long)(a)[2]) <<  8) | \
+                          ((unsigned long)(a)[3]))
+#define WPA_PUT_BE32(a, val)                                        \
+do {                                                                \
+  (a)[0] = (unsigned char)((((unsigned long) (val)) >> 24) & 0xff); \
+  (a)[1] = (unsigned char)((((unsigned long) (val)) >> 16) & 0xff); \
+  (a)[2] = (unsigned char)((((unsigned long) (val)) >> 8) & 0xff);  \
+  (a)[3] = (unsigned char)(((unsigned long) (val)) & 0xff);         \
+} while(0)
+
+#ifdef HAVE_LONGLONG
+#define WPA_PUT_BE64(a, val)                                    \
+do {                                                            \
+  (a)[0] = (unsigned char)(((unsigned long long)(val)) >> 56);  \
+  (a)[1] = (unsigned char)(((unsigned long long)(val)) >> 48);  \
+  (a)[2] = (unsigned char)(((unsigned long long)(val)) >> 40);  \
+  (a)[3] = (unsigned char)(((unsigned long long)(val)) >> 32);  \
+  (a)[4] = (unsigned char)(((unsigned long long)(val)) >> 24);  \
+  (a)[5] = (unsigned char)(((unsigned long long)(val)) >> 16);  \
+  (a)[6] = (unsigned char)(((unsigned long long)(val)) >> 8);   \
+  (a)[7] = (unsigned char)(((unsigned long long)(val)) & 0xff); \
+} while(0)
+#else
+#define WPA_PUT_BE64(a, val)                                  \
+do {                                                          \
+  (a)[0] = (unsigned char)(((unsigned __int64)(val)) >> 56);  \
+  (a)[1] = (unsigned char)(((unsigned __int64)(val)) >> 48);  \
+  (a)[2] = (unsigned char)(((unsigned __int64)(val)) >> 40);  \
+  (a)[3] = (unsigned char)(((unsigned __int64)(val)) >> 32);  \
+  (a)[4] = (unsigned char)(((unsigned __int64)(val)) >> 24);  \
+  (a)[5] = (unsigned char)(((unsigned __int64)(val)) >> 16);  \
+  (a)[6] = (unsigned char)(((unsigned __int64)(val)) >> 8);   \
+  (a)[7] = (unsigned char)(((unsigned __int64)(val)) & 0xff); \
+} while(0)
+#endif
+
+typedef struct sha256_state {
+#ifdef HAVE_LONGLONG
+  unsigned long long length;
+#else
+  unsigned __int64 length;
+#endif
+  unsigned long state[8], curlen;
+  unsigned char buf[64];
+} SHA256_CTX;
+/* the K array */
+static const unsigned long K[64] = {
+  0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
+  0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
+  0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
+  0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
+  0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
+  0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
+  0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
+  0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
+  0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
+  0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
+  0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
+  0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
+  0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
+};
+/* Various logical functions */
+#define RORc(x, y) \
+(((((unsigned long)(x) & 0xFFFFFFFFUL) >> (unsigned long)((y) & 31)) | \
+   ((unsigned long)(x) << (unsigned long)(32 - ((y) & 31)))) & 0xFFFFFFFFUL)
+#define Ch(x,y,z)   (z ^ (x & (y ^ z)))
+#define Maj(x,y,z)  (((x | y) & z) | (x & y))
+#define S(x, n)     RORc((x), (n))
+#define R(x, n)     (((x)&0xFFFFFFFFUL)>>(n))
+#define Sigma0(x)   (S(x, 2) ^ S(x, 13) ^ S(x, 22))
+#define Sigma1(x)   (S(x, 6) ^ S(x, 11) ^ S(x, 25))
+#define Gamma0(x)   (S(x, 7) ^ S(x, 18) ^ R(x, 3))
+#define Gamma1(x)   (S(x, 17) ^ S(x, 19) ^ R(x, 10))
+#ifndef MIN
+#define MIN(x, y)   (((x) < (y)) ? (x) : (y))
+#endif
+/* compress 512-bits */
+static int sha256_compress(struct sha256_state *md,
+                           unsigned char *buf)
+{
+  unsigned long S[8], W[64], t0, t1;
+  unsigned long t;
+  int i;
+  /* copy state into S */
+  for(i = 0; i < 8; i++) {
+    S[i] = md->state[i];
+  }
+  /* copy the state into 512-bits into W[0..15] */
+  for(i = 0; i < 16; i++)
+    W[i] = WPA_GET_BE32(buf + (4 * i));
+  /* fill W[16..63] */
+  for(i = 16; i < 64; i++) {
+    W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) +
+      W[i - 16];
+  }
+  /* Compress */
+#define RND(a,b,c,d,e,f,g,h,i)                    \
+  t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i]; \
+  t1 = Sigma0(a) + Maj(a, b, c);                  \
+  d += t0;                                        \
+  h = t0 + t1;
+  for(i = 0; i < 64; ++i) {
+    RND(S[0], S[1], S[2], S[3], S[4], S[5], S[6], S[7], i);
+    t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4];
+    S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
+  }
+  /* feedback */
+  for(i = 0; i < 8; i++) {
+    md->state[i] = md->state[i] + S[i];
+  }
+  return 0;
+}
+/* Initialize the hash state */
+static void SHA256_Init(struct sha256_state *md)
+{
+  md->curlen = 0;
+  md->length = 0;
+  md->state[0] = 0x6A09E667UL;
+  md->state[1] = 0xBB67AE85UL;
+  md->state[2] = 0x3C6EF372UL;
+  md->state[3] = 0xA54FF53AUL;
+  md->state[4] = 0x510E527FUL;
+  md->state[5] = 0x9B05688CUL;
+  md->state[6] = 0x1F83D9ABUL;
+  md->state[7] = 0x5BE0CD19UL;
+}
+/**
+   Process a block of memory though the hash
+   @param md     The hash state
+   @param in     The data to hash
+   @param inlen  The length of the data (octets)
+   @return CRYPT_OK if successful
+*/
+static int SHA256_Update(struct sha256_state *md,
+                         const unsigned char *in,
+                         unsigned long inlen)
+{
+  unsigned long n;
+#define block_size 64
+  if(md->curlen > sizeof(md->buf))
+    return -1;
+  while(inlen > 0) {
+    if(md->curlen == 0 && inlen >= block_size) {
+      if(sha256_compress(md, (unsigned char *)in) < 0)
+        return -1;
+      md->length += block_size * 8;
+      in += block_size;
+      inlen -= block_size;
+    }
+    else {
+      n = MIN(inlen, (block_size - md->curlen));
+      memcpy(md->buf + md->curlen, in, n);
+      md->curlen += n;
+      in += n;
+      inlen -= n;
+      if(md->curlen == block_size) {
+        if(sha256_compress(md, md->buf) < 0)
+          return -1;
+        md->length += 8 * block_size;
+        md->curlen = 0;
+      }
+    }
+  }
+  return 0;
+}
+/**
+   Terminate the hash to get the digest
+   @param md  The hash state
+   @param out [out] The destination of the hash (32 bytes)
+   @return CRYPT_OK if successful
+*/
+static int SHA256_Final(unsigned char *out,
+                        struct sha256_state *md)
+{
+  int i;
+  if(md->curlen >= sizeof(md->buf))
+    return -1;
+  /* increase the length of the message */
+  md->length += md->curlen * 8;
+  /* append the '1' bit */
+  md->buf[md->curlen++] = (unsigned char)0x80;
+  /* if the length is currently above 56 bytes we append zeros
+   * then compress.  Then we can fall back to padding zeros and length
+   * encoding like normal.
+   */
+  if(md->curlen > 56) {
+    while(md->curlen < 64) {
+      md->buf[md->curlen++] = (unsigned char)0;
+    }
+    sha256_compress(md, md->buf);
+    md->curlen = 0;
+  }
+  /* pad upto 56 bytes of zeroes */
+  while(md->curlen < 56) {
+    md->buf[md->curlen++] = (unsigned char)0;
+  }
+  /* store length */
+  WPA_PUT_BE64(md->buf + 56, md->length);
+  sha256_compress(md, md->buf);
+  /* copy output */
+  for(i = 0; i < 8; i++)
+    WPA_PUT_BE32(out + (4 * i), md->state[i]);
+  return 0;
+}
+/* ===== end - public domain SHA256 implementation ===== */
+
+#endif
+
+void Curl_sha256it(unsigned char *outbuffer, /* 32 unsigned chars */
+                   const unsigned char *input)
+{
+  SHA256_CTX ctx;
+  SHA256_Init(&ctx);
+  SHA256_Update(&ctx, input, curlx_uztoui(strlen((char *)input)));
+  SHA256_Final(outbuffer, &ctx);
+}
+
+#endif /* CURL_DISABLE_CRYPTO_AUTH */
diff --git a/lib/urldata.h b/lib/urldata.h
index 30e13a452..e5aae1430 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -286,6 +286,7 @@ struct digestdata {
   char *qop;
   char *algorithm;
   int nc; /* nounce count */
+  bool userhash;
 #endif
 };
 
diff --git a/lib/vauth/digest.c b/lib/vauth/digest.c
index 185098ed6..131d9da8c 100644
--- a/lib/vauth/digest.c
+++ b/lib/vauth/digest.c
@@ -19,6 +19,7 @@
  * KIND, either express or implied.
  *
  * RFC2831 DIGEST-MD5 authentication
+ * RFC7616 DIGEST-SHA256, DIGEST-SHA512-256 authentication
  *
  ***************************************************************************/
 
@@ -34,6 +35,7 @@
 #include "curl_base64.h"
 #include "curl_hmac.h"
 #include "curl_md5.h"
+#include "curl_sha256.h"
 #include "vtls/vtls.h"
 #include "warnless.h"
 #include "strtok.h"
@@ -144,6 +146,15 @@ static void auth_digest_md5_to_ascii(unsigned char *source, /* 16 bytes */
     snprintf((char *) &dest[i * 2], 3, "%02x", source[i]);
 }
 
+/* Convert sha256 chunk to RFC7616 -suitable ascii string*/
+static void auth_digest_sha256_to_ascii(unsigned char *source, /* 32 bytes */
+                                     unsigned char *dest) /* 65 bytes */
+{
+  int i;
+  for(i = 0; i < 32; i++)
+    snprintf((char *) &dest[i * 2], 3, "%02x", source[i]);
+}
+
 /* Perform quoted-string escaping as described in RFC2616 and its errata */
 static char *auth_digest_string_quoted(const char *source)
 {
@@ -602,9 +613,22 @@ CURLcode Curl_auth_decode_digest_http_message(const char *chlg,
           digest->algo = CURLDIGESTALGO_MD5SESS;
         else if(strcasecompare(content, "MD5"))
           digest->algo = CURLDIGESTALGO_MD5;
+        else if(strcasecompare(content, "SHA-256"))
+          digest->algo = CURLDIGESTALGO_SHA256;
+        else if(strcasecompare(content, "SHA-256-SESS"))
+          digest->algo = CURLDIGESTALGO_SHA256SESS;
+        else if(strcasecompare(content, "SHA-512-256"))
+          digest->algo = CURLDIGESTALGO_SHA512_256;
+        else if(strcasecompare(content, "SHA-512-256-SESS"))
+          digest->algo = CURLDIGESTALGO_SHA512_256SESS;
         else
           return CURLE_BAD_CONTENT_ENCODING;
       }
+      else if(strcasecompare(value, "userhash")) {
+        if(strcasecompare(content, "true")) {
+          digest->userhash = TRUE;
+        }
+      }
       else {
         /* Unknown specifier, ignore it! */
       }
@@ -635,7 +659,7 @@ CURLcode Curl_auth_decode_digest_http_message(const char *chlg,
 }
 
 /*
- * Curl_auth_create_digest_http_message()
+ * _Curl_auth_create_digest_http_message()
  *
  * This is used to generate a HTTP DIGEST response message ready for sending
  * to the recipient.
@@ -654,20 +678,24 @@ CURLcode Curl_auth_decode_digest_http_message(const char *chlg,
  *
  * Returns CURLE_OK on success.
  */
-CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
-                                              const char *userp,
-                                              const char *passwdp,
-                                              const unsigned char *request,
-                                              const unsigned char *uripath,
-                                              struct digestdata *digest,
-                                              char **outptr, size_t *outlen)
+static CURLcode _Curl_auth_create_digest_http_message(
+                  struct Curl_easy *data,
+                  const char *userp,
+                  const char *passwdp,
+                  const unsigned char *request,
+                  const unsigned char *uripath,
+                  struct digestdata *digest,
+                  char **outptr, size_t *outlen,
+                  void (*convert_to_ascii)(unsigned char *, unsigned char *),
+                  void (*hash)(unsigned char *, const unsigned char *))
 {
   CURLcode result;
-  unsigned char md5buf[16]; /* 16 bytes/128 bits */
-  unsigned char request_digest[33];
-  unsigned char *md5this;
-  unsigned char ha1[33];    /* 32 digits and 1 zero byte */
-  unsigned char ha2[33];    /* 32 digits and 1 zero byte */
+  unsigned char hashbuf[32]; /* 32 bytes/256 bits */
+  unsigned char request_digest[65];
+  unsigned char *hashthis;
+  unsigned char ha1[65];    /* 64 digits and 1 zero byte */
+  unsigned char ha2[65];    /* 64 digits and 1 zero byte */
+  char userh[65];
   char cnoncebuf[33];
   char *cnonce = NULL;
   size_t cnonce_sz = 0;
@@ -692,6 +720,17 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
     digest->cnonce = cnonce;
   }
 
+  if(digest->userhash) {
+    hashthis = (unsigned char *) aprintf("%s:%s", userp, digest->realm);
+    if(!hashthis)
+      return CURLE_OUT_OF_MEMORY;
+
+    CURL_OUTPUT_DIGEST_CONV(data, hashthis);
+    hash(hashbuf, hashthis);
+    free(hashthis);
+    convert_to_ascii(hashbuf, (unsigned char *)userh);
+  }
+
   /*
     If the algorithm is "MD5" or unspecified (which then defaults to MD5):
 
@@ -703,26 +742,29 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
            unq(nonce-value) ":" unq(cnonce-value)
   */
 
-  md5this = (unsigned char *)
-    aprintf("%s:%s:%s", userp, digest->realm, passwdp);
-  if(!md5this)
+  hashthis = (unsigned char *)
+    aprintf("%s:%s:%s", digest->userhash ? userh : userp,
+                                    digest->realm, passwdp);
+  if(!hashthis)
     return CURLE_OUT_OF_MEMORY;
 
-  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
-  Curl_md5it(md5buf, md5this);
-  free(md5this);
-  auth_digest_md5_to_ascii(md5buf, ha1);
+  CURL_OUTPUT_DIGEST_CONV(data, hashthis); /* convert on non-ASCII machines */
+  hash(hashbuf, hashthis);
+  free(hashthis);
+  convert_to_ascii(hashbuf, ha1);
 
-  if(digest->algo == CURLDIGESTALGO_MD5SESS) {
+  if(digest->algo == CURLDIGESTALGO_MD5SESS ||
+     digest->algo == CURLDIGESTALGO_SHA256SESS ||
+     digest->algo == CURLDIGESTALGO_SHA512_256SESS) {
     /* nonce and cnonce are OUTSIDE the hash */
     tmp = aprintf("%s:%s:%s", ha1, digest->nonce, digest->cnonce);
     if(!tmp)
       return CURLE_OUT_OF_MEMORY;
 
     CURL_OUTPUT_DIGEST_CONV(data, tmp); /* Convert on non-ASCII machines */
-    Curl_md5it(md5buf, (unsigned char *) tmp);
+    hash(hashbuf, (unsigned char *) tmp);
     free(tmp);
-    auth_digest_md5_to_ascii(md5buf, ha1);
+    convert_to_ascii(hashbuf, ha1);
   }
 
   /*
@@ -738,27 +780,32 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
     5.1.1 of RFC 2616)
   */
 
-  md5this = (unsigned char *) aprintf("%s:%s", request, uripath);
+  hashthis = (unsigned char *) aprintf("%s:%s", request, uripath);
 
   if(digest->qop && strcasecompare(digest->qop, "auth-int")) {
     /* We don't support auth-int for PUT or POST at the moment.
-       TODO: replace md5 of empty string with entity-body for PUT/POST */
-    unsigned char *md5this2 = (unsigned char *)
-      aprintf("%s:%s", md5this, "d41d8cd98f00b204e9800998ecf8427e");
-    free(md5this);
-    md5this = md5this2;
+       TODO: replace hash of empty string with entity-body for PUT/POST */
+    char hashed[65];
+    unsigned char *hashthis2;
+
+    hash(hashbuf, (const unsigned char *)"");
+    convert_to_ascii(hashbuf, (unsigned char *)hashed);
+
+    hashthis2 = (unsigned char *)aprintf("%s:%s", hashthis, hashed);
+    free(hashthis);
+    hashthis = hashthis2;
   }
 
-  if(!md5this)
+  if(!hashthis)
     return CURLE_OUT_OF_MEMORY;
 
-  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
-  Curl_md5it(md5buf, md5this);
-  free(md5this);
-  auth_digest_md5_to_ascii(md5buf, ha2);
+  CURL_OUTPUT_DIGEST_CONV(data, hashthis); /* convert on non-ASCII machines */
+  hash(hashbuf, hashthis);
+  free(hashthis);
+  convert_to_ascii(hashbuf, ha2);
 
   if(digest->qop) {
-    md5this = (unsigned char *) aprintf("%s:%s:%08x:%s:%s:%s",
+    hashthis = (unsigned char *) aprintf("%s:%s:%08x:%s:%s:%s",
                                         ha1,
                                         digest->nonce,
                                         digest->nc,
@@ -767,19 +814,19 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
                                         ha2);
   }
   else {
-    md5this = (unsigned char *) aprintf("%s:%s:%s",
+    hashthis = (unsigned char *) aprintf("%s:%s:%s",
                                         ha1,
                                         digest->nonce,
                                         ha2);
   }
 
-  if(!md5this)
+  if(!hashthis)
     return CURLE_OUT_OF_MEMORY;
 
-  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
-  Curl_md5it(md5buf, md5this);
-  free(md5this);
-  auth_digest_md5_to_ascii(md5buf, request_digest);
+  CURL_OUTPUT_DIGEST_CONV(data, hashthis); /* convert on non-ASCII machines */
+  hash(hashbuf, hashthis);
+  free(hashthis);
+  convert_to_ascii(hashbuf, request_digest);
 
   /* For test case 64 (snooped from a Mozilla 1.3a request)
 
@@ -794,7 +841,7 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
      characters.  algorithm and qop with standard values only contain web-safe
      characters.
   */
-  userp_quoted = auth_digest_string_quoted(userp);
+  userp_quoted = auth_digest_string_quoted(digest->userhash ? userh : userp);
   if(!userp_quoted)
     return CURLE_OUT_OF_MEMORY;
 
@@ -858,6 +905,16 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
     response = tmp;
   }
 
+  if(digest->userhash) {
+    /* Append the userhash */
+    tmp = aprintf("%s, userhash=true", response);
+    free(response);
+    if(!tmp)
+      return CURLE_OUT_OF_MEMORY;
+
+    response = tmp;
+  }
+
   /* Return the output */
   *outptr = response;
   *outlen = strlen(response);
@@ -866,6 +923,58 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
 }
 
 /*
+ * Curl_auth_create_digest_http_message()
+ *
+ * This is used to generate a HTTP DIGEST response message ready for sending
+ * to the recipient.
+ *
+ * Parameters:
+ *
+ * data    [in]     - The session handle.
+ * userp   [in]     - The user name.
+ * passdwp [in]     - The user's password.
+ * request [in]     - The HTTP request.
+ * uripath [in]     - The path of the HTTP uri.
+ * digest  [in/out] - The digest data struct being used and modified.
+ * outptr  [in/out] - The address where a pointer to newly allocated memory
+ *                    holding the result will be stored upon completion.
+ * outlen  [out]    - The length of the output message.
+ *
+ * Returns CURLE_OK on success.
+ */
+CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
+                                              const char *userp,
+                                              const char *passwdp,
+                                              const unsigned char *request,
+                                              const unsigned char *uripath,
+                                              struct digestdata *digest,
+                                              char **outptr, size_t *outlen)
+{
+  switch(digest->algo) {
+  case CURLDIGESTALGO_MD5:
+  case CURLDIGESTALGO_MD5SESS:
+    return _Curl_auth_create_digest_http_message(data, userp, passwdp,
+                                                 request, uripath, digest,
+                                                 outptr, outlen,
+                                                 auth_digest_md5_to_ascii,
+                                                 Curl_md5it);
+
+  case CURLDIGESTALGO_SHA256:
+  case CURLDIGESTALGO_SHA256SESS:
+  case CURLDIGESTALGO_SHA512_256:
+  case CURLDIGESTALGO_SHA512_256SESS:
+    return _Curl_auth_create_digest_http_message(data, userp, passwdp,
+                                                 request, uripath, digest,
+                                                 outptr, outlen,
+                                                 auth_digest_sha256_to_ascii,
+                                                 Curl_sha256it);
+
+  default:
+    return CURLE_UNSUPPORTED_PROTOCOL;
+  }
+}
+
+/*
  * Curl_auth_digest_cleanup()
  *
  * This is used to clean up the digest specific data.
@@ -887,6 +996,7 @@ void Curl_auth_digest_cleanup(struct digestdata *digest)
   digest->nc = 0;
   digest->algo = CURLDIGESTALGO_MD5; /* default algorithm */
   digest->stale = FALSE; /* default means normal, not stale */
+  digest->userhash = FALSE;
 }
 #endif  /* !USE_WINDOWS_SSPI */
 
diff --git a/lib/vauth/digest.h b/lib/vauth/digest.h
index 5722dcece..8686c44a4 100644
--- a/lib/vauth/digest.h
+++ b/lib/vauth/digest.h
@@ -31,7 +31,11 @@
 
 enum {
   CURLDIGESTALGO_MD5,
-  CURLDIGESTALGO_MD5SESS
+  CURLDIGESTALGO_MD5SESS,
+  CURLDIGESTALGO_SHA256,
+  CURLDIGESTALGO_SHA256SESS,
+  CURLDIGESTALGO_SHA512_256,
+  CURLDIGESTALGO_SHA512_256SESS
 };
 
 /* This is used to extract the realm from a challenge message */