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sas: Added DIGEST-MD5 qop-option validation in native challange handling

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Given that we presently support "auth" and not "auth-int" or "auth-conf"
for native challenge-response messages, added client side validation of
the quality-of-protection options from the server's challenge message.
This commit is contained in:
Steve Holme 2014-04-08 21:08:02 +01:00
parent a700f9002c
commit b574e83079
1 changed files with 68 additions and 4 deletions
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72
lib/curl_sasl.c
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@ -40,6 +40,8 @@
#include "curl_sasl.h"
#include "warnless.h"
#include "curl_memory.h"
#include "strtok.h"
#include "rawstr.h"
#ifdef USE_NSS
#include "vtls/nssg.h" /* for Curl_nss_force_init() */
@ -52,6 +54,14 @@
#include "memdebug.h"
#if !defined(CURL_DISABLE_CRYPTO_AUTH) && !defined(USE_WINDOWS_SSPI)
#define DIGEST_QOP_VALUE_AUTH (1 << 0)
#define DIGEST_QOP_VALUE_AUTH_INT (1 << 1)
#define DIGEST_QOP_VALUE_AUTH_CONF (1 << 2)
#define DIGEST_QOP_VALUE_STRING_AUTH "auth"
#define DIGEST_QOP_VALUE_STRING_AUTH_INT "auth-int"
#define DIGEST_QOP_VALUE_STRING_AUTH_CONF "auth-conf"
/* 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
*/
@ -76,6 +86,38 @@ static bool sasl_digest_get_key_value(const char *chlg,
return TRUE;
}
static CURLcode sasl_digest_get_qop_values(const char *options, int *value)
{
char *tmp;
char *token;
char *tok_buf;
/* Initialise the output */
*value = 0;
/* Tokenise the list of qop values. Use a temporary clone of the buffer since
strtok_r() ruins it. */
tmp = strdup(options);
if(!tmp)
return CURLE_OUT_OF_MEMORY;
token = strtok_r(tmp, ",", &tok_buf);
while(token != NULL) {
if(Curl_raw_equal(token, DIGEST_QOP_VALUE_STRING_AUTH))
*value |= DIGEST_QOP_VALUE_AUTH;
else if(Curl_raw_equal(token, DIGEST_QOP_VALUE_STRING_AUTH_INT))
*value |= DIGEST_QOP_VALUE_AUTH_INT;
else if(Curl_raw_equal(token, DIGEST_QOP_VALUE_STRING_AUTH_CONF))
*value |= DIGEST_QOP_VALUE_AUTH_CONF;
token = strtok_r(NULL, ",", &tok_buf);
}
Curl_safefree(tmp);
return CURLE_OK;
}
#endif
/*
@ -279,13 +321,16 @@ CURLcode Curl_sasl_create_cram_md5_message(struct SessionHandle *data,
* rlen [in] - The length of the realm buffer.
* alg [in/out] - The buffer where the algorithm will be stored.
* alen [in] - The length of the algorithm buffer.
* qop [in/out] - The buffer where the qop-options will be stored.
* qlen [in] - The length of the qop buffer.
*
* Returns CURLE_OK on success.
*/
static CURLcode sasl_decode_digest_md5_message(const char *chlg64,
char *nonce, size_t nlen,
char *realm, size_t rlen,
char *alg, size_t alen)
char *alg, size_t alen,
char *qop, size_t qlen)
{
CURLcode result = CURLE_OK;
unsigned char *chlg = NULL;
@ -321,6 +366,12 @@ static CURLcode sasl_decode_digest_md5_message(const char *chlg64,
return CURLE_BAD_CONTENT_ENCODING;
}
/* Retrieve qop-options string from the challenge */
if(!sasl_digest_get_key_value((char *)chlg, "qop=\"", qop, qlen, '\"')) {
Curl_safefree(chlg);
return CURLE_BAD_CONTENT_ENCODING;
}
Curl_safefree(chlg);
return CURLE_OK;
@ -367,22 +418,35 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
char nonce[64];
char realm[128];
char algorithm[64];
char qop_options[64];
int qop_values;
char nonceCount[] = "00000001";
char cnonce[] = "12345678"; /* will be changed */
char method[] = "AUTHENTICATE";
char qop[] = "auth";
char qop[] = DIGEST_QOP_VALUE_STRING_AUTH;
char uri[128];
/* Decode the challange message */
result = sasl_decode_digest_md5_message(chlg64, nonce, sizeof(nonce),
realm, sizeof(realm),
algorithm, sizeof(algorithm));
algorithm, sizeof(algorithm),
qop_options, sizeof(qop_options));
if(result)
return result;
/* We only support md5 sessions */
if(strcmp(algorithm, "md5-sess") != 0)
return CURLE_BAD_CONTENT_ENCODING;
return CURLE_BAD_CONTENT_ENCODING;
/* Get the qop-values from the qop-options */
result = sasl_digest_get_qop_values(qop_options, &qop_values);
if(result)
return result;
/* We only support auth quality-of-protection */
if(!(qop_values & DIGEST_QOP_VALUE_AUTH))
return CURLE_BAD_CONTENT_ENCODING;
#ifndef DEBUGBUILD
/* Generate 64 bits of random data */