http_digest: Moved response generation into SASL module

lib/curl_sasl.c

@@ -43,6 +43,7 @@
 #include "curl_memory.h"
 #include "strtok.h"
 #include "rawstr.h"
+#include "non-ascii.h" /* included for Curl_convert_... prototypes */
 
 #ifdef USE_NSS
 #include "vtls/nssg.h" /* for Curl_nss_force_init() */
@@ -73,6 +74,17 @@ extern void Curl_sasl_gssapi_cleanup(struct kerberos5data *krb5);
 #define DIGEST_MAX_VALUE_LENGTH           256
 #define DIGEST_MAX_CONTENT_LENGTH         1024
 
+/* The CURL_OUTPUT_DIGEST_CONV macro below is for non-ASCII machines.
+   It converts digest text to ASCII so the MD5 will be correct for
+   what ultimately goes over the network.
+*/
+#define CURL_OUTPUT_DIGEST_CONV(a, b) \
+  result = Curl_convert_to_network(a, (char *)b, strlen((const char*)b)); \
+  if(result) { \
+    free(b); \
+    return result; \
+  }
+
 /*
  * Return 0 on success and then the buffers are filled in fine.
  *
@@ -141,6 +153,47 @@ static int sasl_digest_get_pair(const char *str, char *value, char *content,
   return 0; /* all is fine! */
 }
 
+/* Convert md5 chunk to RFC2617 (section 3.1.3) -suitable ascii string*/
+static void sasl_digest_md5_to_ascii(unsigned char *source, /* 16 bytes */
+                                     unsigned char *dest) /* 33 bytes */
+{
+  int i;
+  for(i = 0; i < 16; i++)
+    snprintf((char *)&dest[i*2], 3, "%02x", source[i]);
+}
+
+/* Perform quoted-string escaping as described in RFC2616 and its errata */
+static char *sasl_digest_string_quoted(const char *source)
+{
+  char *dest, *d;
+  const char *s = source;
+  size_t n = 1; /* null terminator */
+
+  /* Calculate size needed */
+  while(*s) {
+    ++n;
+    if(*s == '"' || *s == '\\') {
+      ++n;
+    }
+    ++s;
+  }
+
+  dest = malloc(n);
+  if(dest) {
+    s = source;
+    d = dest;
+    while(*s) {
+      if(*s == '"' || *s == '\\') {
+        *d++ = '\\';
+      }
+      *d++ = *s++;
+    }
+    *d = 0;
+  }
+
+  return dest;
+}
+
 #if !defined(USE_WINDOWS_SSPI)
 /* Retrieves the value for a corresponding key from the challenge string
  * returns TRUE if the key could be found, FALSE if it does not exists
@@ -790,6 +843,236 @@ CURLcode Curl_sasl_decode_digest_http_message(const char *chlg,
   return CURLE_OK;
 }
 
+/*
+ * Curl_sasl_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_sasl_create_digest_http_message(struct SessionHandle *data,
+                                              const char *userp,
+                                              const char *passwdp,
+                                              const unsigned char *request,
+                                              const unsigned char *uripath,
+                                              struct digestdata *digest,
+                                              char **outptr, size_t *outlen)
+{
+  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 */
+  char cnoncebuf[33];
+  char *cnonce = NULL;
+  size_t cnonce_sz = 0;
+  char *userp_quoted;
+  char *response = NULL;
+  char *tmp = NULL;
+
+  if(!digest->nc)
+    digest->nc = 1;
+
+  if(!digest->cnonce) {
+    snprintf(cnoncebuf, sizeof(cnoncebuf), "%08x%08x%08x%08x",
+             Curl_rand(data), Curl_rand(data),
+             Curl_rand(data), Curl_rand(data));
+
+    result = Curl_base64_encode(data, cnoncebuf, strlen(cnoncebuf),
+                                &cnonce, &cnonce_sz);
+    if(result)
+      return result;
+
+    digest->cnonce = cnonce;
+  }
+
+  /*
+    if the algorithm is "MD5" or unspecified (which then defaults to MD5):
+
+    A1 = unq(username-value) ":" unq(realm-value) ":" passwd
+
+    if the algorithm is "MD5-sess" then:
+
+    A1 = H( unq(username-value) ":" unq(realm-value) ":" passwd )
+         ":" unq(nonce-value) ":" unq(cnonce-value)
+  */
+
+  md5this = (unsigned char *)
+    aprintf("%s:%s:%s", userp, digest->realm, passwdp);
+  if(!md5this)
+    return CURLE_OUT_OF_MEMORY;
+
+  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
+  Curl_md5it(md5buf, md5this);
+  Curl_safefree(md5this);
+  sasl_digest_md5_to_ascii(md5buf, ha1);
+
+  if(digest->algo == CURLDIGESTALGO_MD5SESS) {
+    /* 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);
+    Curl_safefree(tmp);
+    sasl_digest_md5_to_ascii(md5buf, ha1);
+  }
+
+  /*
+    If the "qop" directive's value is "auth" or is unspecified, then A2 is:
+
+      A2       = Method ":" digest-uri-value
+
+          If the "qop" value is "auth-int", then A2 is:
+
+      A2       = Method ":" digest-uri-value ":" H(entity-body)
+
+    (The "Method" value is the HTTP request method as specified in section
+    5.1.1 of RFC 2616)
+  */
+
+  md5this = (unsigned char *)aprintf("%s:%s", request, uripath);
+
+  if(digest->qop && Curl_raw_equal(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");
+    Curl_safefree(md5this);
+    md5this = md5this2;
+  }
+
+  if(!md5this)
+    return CURLE_OUT_OF_MEMORY;
+
+  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
+  Curl_md5it(md5buf, md5this);
+  Curl_safefree(md5this);
+  sasl_digest_md5_to_ascii(md5buf, ha2);
+
+  if(digest->qop) {
+    md5this = (unsigned char *)aprintf("%s:%s:%08x:%s:%s:%s",
+                                       ha1,
+                                       digest->nonce,
+                                       digest->nc,
+                                       digest->cnonce,
+                                       digest->qop,
+                                       ha2);
+  }
+  else {
+    md5this = (unsigned char *)aprintf("%s:%s:%s",
+                                       ha1,
+                                       digest->nonce,
+                                       ha2);
+  }
+
+  if(!md5this)
+    return CURLE_OUT_OF_MEMORY;
+
+  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
+  Curl_md5it(md5buf, md5this);
+  Curl_safefree(md5this);
+  sasl_digest_md5_to_ascii(md5buf, request_digest);
+
+  /* for test case 64 (snooped from a Mozilla 1.3a request)
+
+    Authorization: Digest username="testuser", realm="testrealm", \
+    nonce="1053604145", uri="/64", response="c55f7f30d83d774a3d2dcacf725abaca"
+
+    Digest parameters are all quoted strings.  Username which is provided by
+    the user will need double quotes and backslashes within it escaped.  For
+    the other fields, this shouldn't be an issue.  realm, nonce, and opaque
+    are copied as is from the server, escapes and all.  cnonce is generated
+    with web-safe characters.  uri is already percent encoded.  nc is 8 hex
+    characters.  algorithm and qop with standard values only contain web-safe
+    chracters.
+  */
+  userp_quoted = sasl_digest_string_quoted(userp);
+  if(!userp_quoted)
+    return CURLE_OUT_OF_MEMORY;
+
+  if(digest->qop) {
+    response = aprintf("username=\"%s\", "
+                       "realm=\"%s\", "
+                       "nonce=\"%s\", "
+                       "uri=\"%s\", "
+                       "cnonce=\"%s\", "
+                       "nc=%08x, "
+                       "qop=%s, "
+                       "response=\"%s\"",
+                       userp_quoted,
+                       digest->realm,
+                       digest->nonce,
+                       uripath,
+                       digest->cnonce,
+                       digest->nc,
+                       digest->qop,
+                       request_digest);
+
+    if(Curl_raw_equal(digest->qop, "auth"))
+      digest->nc++; /* The nc (from RFC) has to be a 8 hex digit number 0
+                       padded which tells to the server how many times you are
+                       using the same nonce in the qop=auth mode */
+  }
+  else {
+    response = aprintf("username=\"%s\", "
+                       "realm=\"%s\", "
+                       "nonce=\"%s\", "
+                       "uri=\"%s\", "
+                       "response=\"%s\"",
+                       userp_quoted,
+                       digest->realm,
+                       digest->nonce,
+                       uripath,
+                       request_digest);
+  }
+  Curl_safefree(userp_quoted);
+  if(!response)
+    return CURLE_OUT_OF_MEMORY;
+
+  /* Add the optional fields */
+  if(digest->opaque) {
+    /* Append the opaque */
+    tmp = aprintf("%s, opaque=\"%s\"", response, digest->opaque);
+    if(!tmp)
+      return CURLE_OUT_OF_MEMORY;
+
+    free(response);
+    response = tmp;
+  }
+
+  if(digest->algorithm) {
+    /* Append the algorithm */
+    tmp = aprintf("%s, algorithm=\"%s\"", response, digest->algorithm);
+    if(!tmp)
+      return CURLE_OUT_OF_MEMORY;
+
+    free(response);
+    response = tmp;
+  }
+
+  /* Return the output */
+  *outptr = response;
+  *outlen = strlen(response);
+
+  return CURLE_OK;
+}
+
 /*
  * Curl_sasl_digest_cleanup()
  *

lib/curl_sasl.h

@@ -109,6 +109,15 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
 CURLcode Curl_sasl_decode_digest_http_message(const char *chlg,
                                               struct digestdata *digest);
 
+/* This is used to generate a HTTP DIGEST response message */
+CURLcode Curl_sasl_create_digest_http_message(struct SessionHandle *data,
+                                              const char *userp,
+                                              const char *passwdp,
+                                              const unsigned char *request,
+                                              const unsigned char *uri,
+                                              struct digestdata *digest,
+                                              char **outptr, size_t *outlen);
+
 /* This is used to clean up the digest specific data */
 void Curl_sasl_digest_cleanup(struct digestdata *digest);
 #endif

lib/http_digest.c

@@ -26,15 +26,9 @@
 
 #include "urldata.h"
 #include "rawstr.h"
-#include "curl_base64.h"
-#include "curl_md5.h"
 #include "curl_sasl.h"
 #include "http_digest.h"
-#include "strtok.h"
 #include "curl_memory.h"
-#include "vtls/vtls.h" /* for Curl_rand() */
-#include "non-ascii.h" /* included for Curl_convert_... prototypes */
-#include "warnless.h"
 
 #define _MPRINTF_REPLACE /* use our functions only */
 #include <curl/mprintf.h>
@@ -74,85 +68,29 @@ CURLcode Curl_input_digest(struct connectdata *conn,
   return Curl_sasl_decode_digest_http_message(header, d);
 }
 
-/* convert md5 chunk to RFC2617 (section 3.1.3) -suitable ascii string*/
-static void md5_to_ascii(unsigned char *source, /* 16 bytes */
-                         unsigned char *dest) /* 33 bytes */
-{
-  int i;
-  for(i=0; i<16; i++)
-    snprintf((char *)&dest[i*2], 3, "%02x", source[i]);
-}
-
-/* Perform quoted-string escaping as described in RFC2616 and its errata */
-static char *string_quoted(const char *source)
-{
-  char *dest, *d;
-  const char *s = source;
-  size_t n = 1; /* null terminator */
-
-  /* Calculate size needed */
-  while(*s) {
-    ++n;
-    if(*s == '"' || *s == '\\') {
-      ++n;
-    }
-    ++s;
-  }
-
-  dest = malloc(n);
-  if(dest) {
-    s = source;
-    d = dest;
-    while(*s) {
-      if(*s == '"' || *s == '\\') {
-        *d++ = '\\';
-      }
-      *d++ = *s++;
-    }
-    *d = 0;
-  }
-
-  return dest;
-}
-
 CURLcode Curl_output_digest(struct connectdata *conn,
                             bool proxy,
                             const unsigned char *request,
                             const unsigned char *uripath)
 {
-  /* We have a Digest setup for this, use it!  Now, to get all the details for
-     this sorted out, I must urge you dear friend to read up on the RFC2617
-     section 3.2.2, */
-  size_t urilen;
-  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 */
-  char cnoncebuf[33];
-  char *cnonce = NULL;
-  size_t cnonce_sz = 0;
-  char *tmp = NULL;
-  char **allocuserpwd;
-  size_t userlen;
-  const char *userp;
-  char *userp_quoted;
-  const char *passwdp;
-  struct auth *authp;
-
-  struct SessionHandle *data = conn->data;
-  struct digestdata *d;
   CURLcode result;
-/* The CURL_OUTPUT_DIGEST_CONV macro below is for non-ASCII machines.
+  struct SessionHandle *data = conn->data;
-   It converts digest text to ASCII so the MD5 will be correct for
+  unsigned char *path;
-   what ultimately goes over the network.
+  unsigned char *tmp;
-*/
+  char *response;
-#define CURL_OUTPUT_DIGEST_CONV(a, b) \
+  size_t len;
-  result = Curl_convert_to_network(a, (char *)b, strlen((const char*)b)); \
+
-  if(result) { \
+  /* Point to the address of the pointer that holds the string to send to the
-    free(b); \
+     server, which is for a plain host or for a HTTP proxy */
-    return result; \
+  char **allocuserpwd;
-  }
+
+  /* Point to the name and password for this */
+  const char *userp;
+  const char *passwdp;
+
+  /* Point to the correct struct with this */
+  struct digestdata *d;
+  struct auth *authp;
 
   if(proxy) {
     d = &data->state.proxydigest;
@@ -182,68 +120,6 @@ CURLcode Curl_output_digest(struct connectdata *conn,
     authp->done = FALSE;
     return CURLE_OK;
   }
-  authp->done = TRUE;
-
-  if(!d->nc)
-    d->nc = 1;
-
-  if(!d->cnonce) {
-    snprintf(cnoncebuf, sizeof(cnoncebuf), "%08x%08x%08x%08x",
-             Curl_rand(data), Curl_rand(data),
-             Curl_rand(data), Curl_rand(data));
-
-    result = Curl_base64_encode(data, cnoncebuf, strlen(cnoncebuf),
-                                &cnonce, &cnonce_sz);
-    if(result)
-      return result;
-
-    d->cnonce = cnonce;
-  }
-
-  /*
-    if the algorithm is "MD5" or unspecified (which then defaults to MD5):
-
-    A1 = unq(username-value) ":" unq(realm-value) ":" passwd
-
-    if the algorithm is "MD5-sess" then:
-
-    A1 = H( unq(username-value) ":" unq(realm-value) ":" passwd )
-         ":" unq(nonce-value) ":" unq(cnonce-value)
-  */
-
-  md5this = (unsigned char *)
-    aprintf("%s:%s:%s", userp, d->realm, passwdp);
-  if(!md5this)
-    return CURLE_OUT_OF_MEMORY;
-
-  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
-  Curl_md5it(md5buf, md5this);
-  Curl_safefree(md5this);
-  md5_to_ascii(md5buf, ha1);
-
-  if(d->algo == CURLDIGESTALGO_MD5SESS) {
-    /* nonce and cnonce are OUTSIDE the hash */
-    tmp = aprintf("%s:%s:%s", ha1, d->nonce, d->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);
-    Curl_safefree(tmp);
-    md5_to_ascii(md5buf, ha1);
-  }
-
-  /*
-    If the "qop" directive's value is "auth" or is unspecified, then A2 is:
-
-      A2       = Method ":" digest-uri-value
-
-          If the "qop" value is "auth-int", then A2 is:
-
-      A2       = Method ":" digest-uri-value ":" H(entity-body)
-
-    (The "Method" value is the HTTP request method as specified in section
-    5.1.1 of RFC 2616)
-  */
 
   /* So IE browsers < v7 cut off the URI part at the query part when they
      evaluate the MD5 and some (IIS?) servers work with them so we may need to
@@ -258,141 +134,30 @@ CURLcode Curl_output_digest(struct connectdata *conn,
      http://www.fngtps.com/2006/09/http-authentication
   */
 
-  if(authp->iestyle && ((tmp = strchr((char *)uripath, '?')) != NULL))
+  if(authp->iestyle && ((tmp = strchr((char *)uripath, '?')) != NULL)) {
-    urilen = tmp - (char *)uripath;
+    size_t urilen = tmp - (char *)uripath;
+
+    path = aprintf("%.*s", urilen, uripath);
+  }
   else
-    urilen = strlen((char *)uripath);
+    path = strdup((char *) uripath);
 
-  md5this = (unsigned char *)aprintf("%s:%.*s", request, urilen, uripath);
+  if(!path)
-
-  if(d->qop && Curl_raw_equal(d->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");
-    Curl_safefree(md5this);
-    md5this = md5this2;
-  }
-
-  if(!md5this)
     return CURLE_OUT_OF_MEMORY;
 
-  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
+  result = Curl_sasl_create_digest_http_message(data, userp, passwdp, request,
-  Curl_md5it(md5buf, md5this);
+                                                path, d, &response, &len);
-  Curl_safefree(md5this);
+  free(path);
-  md5_to_ascii(md5buf, ha2);
+  if(result)
+    return result;
 
-  if(d->qop) {
+  *allocuserpwd = aprintf("%sAuthorization: Digest %s\r\n",
-    md5this = (unsigned char *)aprintf("%s:%s:%08x:%s:%s:%s",
+                          proxy ? "Proxy-" : "",
-                                       ha1,
+                          response);
-                                       d->nonce,
-                                       d->nc,
-                                       d->cnonce,
-                                       d->qop,
-                                       ha2);
-  }
-  else {
-    md5this = (unsigned char *)aprintf("%s:%s:%s",
-                                       ha1,
-                                       d->nonce,
-                                       ha2);
-  }
-  if(!md5this)
-    return CURLE_OUT_OF_MEMORY;
-
-  CURL_OUTPUT_DIGEST_CONV(data, md5this); /* convert on non-ASCII machines */
-  Curl_md5it(md5buf, md5this);
-  Curl_safefree(md5this);
-  md5_to_ascii(md5buf, request_digest);
-
-  /* for test case 64 (snooped from a Mozilla 1.3a request)
-
-    Authorization: Digest username="testuser", realm="testrealm", \
-    nonce="1053604145", uri="/64", response="c55f7f30d83d774a3d2dcacf725abaca"
-
-    Digest parameters are all quoted strings.  Username which is provided by
-    the user will need double quotes and backslashes within it escaped.  For
-    the other fields, this shouldn't be an issue.  realm, nonce, and opaque
-    are copied as is from the server, escapes and all.  cnonce is generated
-    with web-safe characters.  uri is already percent encoded.  nc is 8 hex
-    characters.  algorithm and qop with standard values only contain web-safe
-    chracters.
-  */
-  userp_quoted = string_quoted(userp);
-  if(!userp_quoted)
-    return CURLE_OUT_OF_MEMORY;
-
-  if(d->qop) {
-    *allocuserpwd =
-      aprintf( "%sAuthorization: Digest "
-               "username=\"%s\", "
-               "realm=\"%s\", "
-               "nonce=\"%s\", "
-               "uri=\"%.*s\", "
-               "cnonce=\"%s\", "
-               "nc=%08x, "
-               "qop=%s, "
-               "response=\"%s\"",
-               proxy?"Proxy-":"",
-               userp_quoted,
-               d->realm,
-               d->nonce,
-               urilen, uripath, /* this is the PATH part of the URL */
-               d->cnonce,
-               d->nc,
-               d->qop,
-               request_digest);
-
-    if(Curl_raw_equal(d->qop, "auth"))
-      d->nc++; /* The nc (from RFC) has to be a 8 hex digit number 0 padded
-                  which tells to the server how many times you are using the
-                  same nonce in the qop=auth mode. */
-  }
-  else {
-    *allocuserpwd =
-      aprintf( "%sAuthorization: Digest "
-               "username=\"%s\", "
-               "realm=\"%s\", "
-               "nonce=\"%s\", "
-               "uri=\"%.*s\", "
-               "response=\"%s\"",
-               proxy?"Proxy-":"",
-               userp_quoted,
-               d->realm,
-               d->nonce,
-               urilen, uripath, /* this is the PATH part of the URL */
-               request_digest);
-  }
-  Curl_safefree(userp_quoted);
   if(!*allocuserpwd)
     return CURLE_OUT_OF_MEMORY;
 
-  /* Add optional fields */
+  authp->done = TRUE;
-  if(d->opaque) {
-    /* append opaque */
-    tmp = aprintf("%s, opaque=\"%s\"", *allocuserpwd, d->opaque);
-    if(!tmp)
-      return CURLE_OUT_OF_MEMORY;
-    free(*allocuserpwd);
-    *allocuserpwd = tmp;
-  }
-
-  if(d->algorithm) {
-    /* append algorithm */
-    tmp = aprintf("%s, algorithm=\"%s\"", *allocuserpwd, d->algorithm);
-    if(!tmp)
-      return CURLE_OUT_OF_MEMORY;
-    free(*allocuserpwd);
-    *allocuserpwd = tmp;
-  }
-
-  /* append CRLF + zero (3 bytes) to the userpwd header */
-  userlen = strlen(*allocuserpwd);
-  tmp = realloc(*allocuserpwd, userlen + 3);
-  if(!tmp)
-    return CURLE_OUT_OF_MEMORY;
-  strcpy(&tmp[userlen], "\r\n"); /* append the data */
-  *allocuserpwd = tmp;
 
   return CURLE_OK;
 }