From cbbe71752d7f9c6204ab0f16600fe7f10490f203 Mon Sep 17 00:00:00 2001
From: Stef Walter <stef@memberwebs.com>
Date: Sat, 24 Apr 2004 22:38:50 +0000
Subject: Completed implementation of ldap/ntlm/simple handlers

---
 daemon/digest.c | 533 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 533 insertions(+)
 create mode 100644 daemon/digest.c

(limited to 'daemon/digest.c')

diff --git a/daemon/digest.c b/daemon/digest.c
new file mode 100644
index 0000000..51120a0
--- /dev/null
+++ b/daemon/digest.c
@@ -0,0 +1,533 @@
+
+#include "usuals.h"
+#include "md5.h"
+#include "httpauthd.h"
+#include "digest.h"
+
+#include <syslog.h>
+
+/* A globally unique counter used to guarantee uniqueness of nonces */
+static unsigned int g_digest_unique = 0;
+
+typedef struct internal_nonce
+{
+  unsigned char hash[MD5_LEN];
+  time_t tm;
+  unsigned int unique;
+}
+internal_nonce_t;
+
+void digest_makenonce(unsigned char* nonce, unsigned char* secret, unsigned char* old)
+{
+  internal_nonce_t in;
+  md5_ctx_t md5;
+
+  ASSERT(sizeof(internal_nonce_t) == DIGEST_NONCE_LEN);
+
+  if(old)
+  {
+    internal_nonce_t* nold = (internal_nonce_t*)old;
+    in.tm = nold->tm;
+    in.unique = nold->unique;
+  }
+  else
+  {
+    in.tm = time(NULL);
+    ha_lock(NULL);
+      in.unique = g_digest_unique++;
+    ha_unlock(NULL);
+  }
+
+  md5_init(&md5);
+  md5_update(&md5, secret, DIGEST_SECRET_LEN);
+  md5_update(&md5, &(in.tm), sizeof(in.tm));
+  md5_update(&md5, &(in.unique), sizeof(in.unique));
+  md5_final(in.hash, &md5);
+
+  memcpy(nonce, &in, DIGEST_NONCE_LEN);
+}
+
+int digest_checknonce(unsigned char* nonce, unsigned char* secret, time_t* tm)
+{
+  internal_nonce_t in;
+
+  ASSERT(sizeof(internal_nonce_t) == DIGEST_NONCE_LEN);
+
+  digest_makenonce((unsigned char*)&in, secret, nonce);
+
+  if(memcmp((unsigned char*)&in, nonce, DIGEST_SECRET_LEN) == 0)
+  {
+    if(tm)
+      *tm = in.tm;
+
+    return HA_OK;
+  }
+
+  return HA_FALSE;
+}
+
+digest_record_t* digest_makerec(unsigned char* nonce, const char* user)
+{
+  digest_record_t* rec = (digest_record_t*)malloc(sizeof(*rec));
+  if(!rec)
+  {
+    ha_messagex(LOG_CRIT, "out of memory");
+    return NULL;
+  }
+
+  memset(rec, 0, sizeof(*rec));
+  memcpy(rec->nonce, nonce, DIGEST_NONCE_LEN);
+
+  md5_string(rec->userhash, user);
+  return rec;
+}
+
+const char* digest_challenge(ha_buffer_t* buf, unsigned char* nonce,
+                             const char* realm, const char* domains, int stale)
+{
+  ASSERT(realm);
+  ASSERT(nonce);
+
+  ha_bufmcat(buf, HA_PREFIX_DIGEST, " realm=\"", realm, "\", nonce=\"", NULL);
+  ha_bufjoin(buf);
+  ha_bufenc64(buf, nonce, DIGEST_NONCE_LEN);
+  ha_bufjoin(buf);
+  ha_bufmcat(buf, "\", qop=\"auth\", algorithm=\"MD5\"", NULL);
+
+  if(domains)
+  {
+    ha_bufjoin(buf);
+    ha_bufmcat(buf, ", domain=\"", domains, "\"", NULL);
+  }
+
+  if(stale)
+  {
+    ha_bufjoin(buf);
+    ha_bufcat(buf, ", stale=true");
+  }
+
+  return ha_bufdata(buf);
+}
+
+/*
+ * Copyright 1999-2004 The Apache Software Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+int digest_parse(char* header, ha_buffer_t* buf, digest_header_t* rec,
+                   unsigned char* nonce)
+{
+  /*
+   * This function destroys the contents of header by
+   * terminating strings in it all over the place.
+   */
+
+  char next;
+  char* key;
+  char* value;
+
+  header = ha_bufcpy(buf, header);
+
+  if(!header)
+    return HA_ERROR;
+
+  memset(rec, 0, sizeof(rec));
+
+  while(header[0])
+  {
+    /* find key */
+
+    while(header[0] && isspace(header[0]))
+      header++;
+
+    key = header;
+
+    while(header[0] && header[0] != '=' && header[0] != ',' &&
+          !isspace(header[0]))
+      header++;
+
+    /* null terminate and move on */
+    next = header[0];
+    header[0] = '\0';
+    header++;
+
+    if(!next)
+      break;
+
+    if(isspace(header[0]))
+    {
+      while(header[0] && isspace(header[0]))
+        header++;
+
+      next = header[0];
+    }
+
+    /* find value */
+
+    if(next == '=')
+    {
+      header++;
+
+      while(header[0] && isspace(header[0]))
+        header++;
+
+      if(header[0] == '\"')          /* quoted string */
+      {
+        header++;
+        value = header;
+
+        while(header[0] && header[0] != '\"')
+          header++;
+
+        header[0] = 0;
+        header++;
+      }
+
+      else                          /* token */
+      {
+        value = header;
+
+        while(header[0] && header[0] != ',' && !isspace(header[0]))
+          header++;
+
+        header[0] = 0;
+        header++;
+      }
+
+      while(header[0] && header[0] != ',')
+        header++;
+
+      if(header[0])
+        header++;
+
+      if(!strcasecmp(key, "username"))
+        rec->username = value;
+      else if(!strcasecmp(key, "realm"))
+        rec->realm = value;
+      else if (!strcasecmp(key, "nonce"))
+        rec->nonce = value;
+      else if (!strcasecmp(key, "uri"))
+        rec->uri = value;
+      else if (!strcasecmp(key, "response"))
+        rec->digest = value;
+      else if (!strcasecmp(key, "algorithm"))
+        rec->algorithm = value;
+      else if (!strcasecmp(key, "cnonce"))
+        rec->cnonce = value;
+      else if (!strcasecmp(key, "opaque"))
+        rec->opaque = value;
+      else if (!strcasecmp(key, "qop"))
+        rec->qop = value;
+      else if (!strcasecmp(key, "nc"))
+        rec->nc = value;
+    }
+  }
+
+  if(nonce)
+  {
+    memset(nonce, 0, DIGEST_NONCE_LEN);
+
+    if(rec->nonce)
+    {
+      void* d = ha_bufdec64(buf, rec->nonce, DIGEST_NONCE_LEN);
+
+      if(d != NULL)
+        memcpy(nonce, d, DIGEST_NONCE_LEN);
+    }
+  }
+
+  return HA_OK;
+}
+
+int digest_check(const char* realm, const char* method, const char* uri,
+                   ha_buffer_t* buf, digest_header_t* dg, digest_record_t* rec)
+{
+  unsigned char hash[MD5_LEN];
+  md5_ctx_t md5;
+  const char* digest;
+  const char* t;
+
+  /* Check for digest */
+  if(!dg->digest || !dg->digest[0])
+  {
+    ha_messagex(LOG_WARNING, "digest response missing digest");
+    return HA_FALSE;
+  }
+
+  /* Username */
+  if(!dg->username || !dg->username[0] ||
+     md5_strcmp(rec->userhash, dg->username) != 0)
+  {
+    ha_messagex(LOG_WARNING, "digest response missing username");
+    return HA_FALSE;
+  }
+
+  /* The realm */
+  if(!dg->realm || strcmp(dg->realm, realm) != 0)
+  {
+    ha_messagex(LOG_WARNING, "digest response contains invalid realm: '%s'",
+                dg->realm ? dg->realm : "");
+    return HA_FALSE;
+  }
+
+  /* Components in the new RFC */
+  if(dg->qop)
+  {
+    /*
+     * We only support 'auth' qop. We don't have access to the data
+     * and wouldn't be able to support anything else.
+     */
+    if(strcmp(dg->qop, "auth") != 0)
+    {
+      ha_messagex(LOG_WARNING, "digest response contains unknown or unsupported qop: '%s'",
+                  dg->qop ? dg->qop : "");
+      return HA_FALSE;
+    }
+
+    /* The cnonce */
+    if(!dg->cnonce || !dg->cnonce[0])
+    {
+      ha_messagex(LOG_WARNING, "digest response is missing cnonce value");
+      return HA_FALSE;
+    }
+
+    /* The nonce count */
+    if(!dg->nc || !dg->nc[0])
+    {
+      ha_messagex(LOG_WARNING, "digest response is missing nc value");
+      return HA_FALSE;
+    }
+
+    /* Validate the nc */
+    else
+    {
+      char* e;
+      long nc = strtol(dg->nc, &e, 10);
+
+      if(e != (dg->nc + strlen(e)) || nc != rec->nc)
+      {
+        ha_messagex(LOG_WARNING, "digest response has invalid nc value: %s",
+                    dg->nc);
+        return HA_FALSE;
+      }
+    }
+  }
+
+  /* The algorithm */
+  if(dg->algorithm && strcasecmp(dg->algorithm, "MD5") != 0)
+  {
+    ha_messagex(LOG_WARNING, "digest response contains unknown or unsupported algorithm: '%s'",
+                dg->algorithm ? dg->algorithm : "");
+    return HA_FALSE;
+  }
+
+  /* Request URI */
+  if(!dg->uri)
+  {
+    ha_messagex(LOG_WARNING, "digest response is missing uri");
+    return HA_FALSE;
+  }
+
+  if(strcmp(dg->uri, uri) != 0)
+  {
+    ha_uri_t d_uri;
+    ha_uri_t s_uri;
+
+    if(ha_uriparse(buf, dg->uri, &d_uri) == HA_ERROR)
+    {
+      ha_messagex(LOG_WARNING, "digest response constains invalid uri: %s", dg->uri);
+      return HA_FALSE;
+    }
+
+    if(ha_uriparse(buf, uri, &s_uri) == HA_ERROR)
+    {
+      ha_messagex(LOG_ERR, "server sent us an invalid uri");
+      return HA_ERROR;
+    }
+
+    if(ha_uricmp(&d_uri, &s_uri) != 0)
+    {
+      ha_messagex(LOG_WARNING, "digest response contains wrong uri: %s "
+                               "(should be %s)", dg->uri, uri);
+      return HA_ERROR;
+    }
+  }
+
+  /*
+   * nonce: should have already been validated by the caller who
+   * found this nice rec structure to pass us.
+   *
+   * opaque: We also don't use opaque. The caller should have validated it
+   * if it's used there.
+   */
+
+  /*
+   * Now we validate the digest response
+   */
+
+  /* Encode ha1 */
+  t = ha_bufenchex(buf, rec->ha1, MD5_LEN);
+
+  if(t == NULL)
+    return HA_ERROR;
+
+  /* Encode ha2 */
+  md5_init(&md5);
+  md5_update(&md5, method, strlen(method));
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, dg->uri, strlen(dg->uri));
+  md5_final(hash, &md5);
+
+  ha_bufenchex(buf, hash, MD5_LEN);
+
+  if(!ha_bufdata(buf))
+    return HA_ERROR;
+
+
+  /* Old style digest (RFC 2069) */
+  if(!dg->qop)
+  {
+    md5_init(&md5);
+    md5_update(&md5, t, MD5_LEN * 2);                /* ha1 */
+    md5_update(&md5, ":", 1);
+    md5_update(&md5, dg->nonce, strlen(dg->nonce));  /* nonce */
+    md5_update(&md5, ":", 1);
+    md5_update(&md5, ha_bufdata(buf), MD5_LEN * 2);  /* ha1 */
+    md5_final(hash, &md5);
+  }
+
+  /* New style 'auth' digest (RFC 2617) */
+  else
+  {
+    md5_init(&md5);
+    md5_update(&md5, t, MD5_LEN * 2);                  /* ha1 */
+    md5_update(&md5, ":", 1);
+    md5_update(&md5, dg->nonce, strlen(dg->nonce));    /* nonce */
+    md5_update(&md5, ":", 1);
+    md5_update(&md5, dg->nc, strlen(dg->nc));          /* nc */
+    md5_update(&md5, ":", 1);
+    md5_update(&md5, dg->cnonce, strlen(dg->cnonce));  /* cnonce */
+    md5_update(&md5, ":", 1);
+    md5_update(&md5, dg->qop, strlen(dg->qop));        /* qop */
+    md5_update(&md5, ":", 1);
+    md5_update(&md5, ha_bufdata(buf), MD5_LEN * 2);    /* ha2 */
+    md5_final(hash, &md5);
+  }
+
+  /* Encode the digest */
+  digest = ha_bufenchex(buf, hash, MD5_LEN);
+
+  if(digest == NULL)
+    return HA_ERROR;
+
+  if(strcasecmp(dg->digest, digest) != 0)
+  {
+    ha_messagex(LOG_WARNING, "digest authentication failed for user: %s", dg->username);
+    return HA_FALSE;
+  }
+
+  return HA_OK;
+}
+
+const char* digest_respond(ha_buffer_t* buf, digest_header_t* dg,
+                           digest_record_t* rec, unsigned char* next)
+{
+  unsigned char hash[MD5_LEN];
+  md5_ctx_t md5;
+  const char* nextnonce = NULL;
+  const char* t;
+
+  if(next)
+  {
+    nextnonce = ha_bufenc64(buf, next, DIGEST_NONCE_LEN);
+
+    if(nextnonce == NULL)
+      return NULL;
+  }
+
+  /* For older clients RFC 2069 */
+  if(dg->qop)
+  {
+    if(nextnonce)
+      ha_bufmcat(buf, "nextnonce=\"", nextnonce, "\"", NULL);
+
+    return ha_bufdata(buf);
+  }
+
+  /* Otherwise we do the whole song and dance */
+
+  /* Encode ha1 */
+  t = ha_bufenchex(buf, rec->ha1, MD5_LEN);
+
+  if(t == NULL)
+    return NULL;
+
+  /* Encode ha2 */
+  md5_init(&md5);
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, dg->uri, strlen(dg->uri));
+  md5_final(hash, &md5);
+
+  ha_bufenchex(buf, hash, MD5_LEN);
+
+  if(!ha_bufdata(buf))
+    return NULL;
+
+  /* New style 'auth' digest (RFC 2617) */
+  md5_init(&md5);
+  md5_update(&md5, t, MD5_LEN * 2);                  /* ha1 */
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, dg->nonce, strlen(dg->nonce));    /* nonce */
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, dg->nc, strlen(dg->nc));          /* nc */
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, dg->cnonce, strlen(dg->cnonce));  /* cnonce */
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, dg->qop, strlen(dg->qop));        /* qop */
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, ha_bufdata(buf), MD5_LEN * 2);    /* ha2 */
+  md5_final(hash, &md5);
+
+  /* Encode the digest */
+  t = ha_bufenchex(buf, hash, MD5_LEN);
+
+  if(t == NULL)
+    return NULL;
+
+  ha_bufmcat(buf, "rspauth=\"", t, "\"",
+                 " qop=", dg->qop,
+                 " nc=", dg->nc,
+                 " cnonce=\"", dg->cnonce, "\"", NULL);
+
+  if(nextnonce)
+  {
+    ha_bufjoin(buf);
+    ha_bufmcat(buf, " nextnonce=\"", nextnonce, "\"", NULL);
+  }
+
+  return ha_bufdata(buf);
+}
+
+void digest_makeha1(unsigned char* digest, const char* user,
+                    const char* realm, const char* password)
+{
+  md5_ctx_t md5;
+  md5_init(&md5);
+  md5_update(&md5, user, strlen(user));
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, realm, strlen(realm));
+  md5_update(&md5, ":", 1);
+  md5_update(&md5, password, strlen(password));
+  md5_final(digest, &md5);
+}
\ No newline at end of file
-- 
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