+/*
+ * '_httpSetDigestAuthString()' - Calculate a Digest authentication response
+ * using the appropriate RFC 2068/2617/7616
+ * algorithm.
+ */
+
+int /* O - 1 on success, 0 on failure */
+_httpSetDigestAuthString(
+ http_t *http, /* I - HTTP connection */
+ const char *nonce, /* I - Nonce value */
+ const char *method, /* I - HTTP method */
+ const char *resource) /* I - HTTP resource path */
+{
+ char kd[65], /* Final MD5/SHA-256 digest */
+ ha1[65], /* Hash of username:realm:password */
+ ha2[65], /* Hash of method:request-uri */
+ username[HTTP_MAX_VALUE],
+ /* username:password */
+ *password, /* Pointer to password */
+ temp[1024], /* Temporary string */
+ digest[1024]; /* Digest auth data */
+ unsigned char hash[32]; /* Hash buffer */
+ size_t hashsize; /* Size of hash */
+
+
+ DEBUG_printf(("2_httpSetDigestAuthString(http=%p, nonce=\"%s\", method=\"%s\", resource=\"%s\")", http, nonce, method, resource));
+
+ if (nonce && *nonce && strcmp(nonce, http->nonce))
+ {
+ strlcpy(http->nonce, nonce, sizeof(http->nonce));
+
+ if (nonce == http->nextnonce)
+ http->nextnonce[0] = '\0';
+
+ http->nonce_count = 1;
+ }
+ else
+ http->nonce_count ++;
+
+ strlcpy(username, http->userpass, sizeof(username));
+ if ((password = strchr(username, ':')) != NULL)
+ *password++ = '\0';
+ else
+ return (0);
+
+ if (http->algorithm[0])
+ {
+ /*
+ * Follow RFC 2617/7616...
+ */
+
+ int i; /* Looping var */
+ char cnonce[65]; /* cnonce value */
+ const char *hashalg; /* Hashing algorithm */
+
+ for (i = 0; i < 64; i ++)
+ cnonce[i] = "0123456789ABCDEF"[CUPS_RAND() & 15];
+ cnonce[64] = '\0';
+
+ if (!_cups_strcasecmp(http->algorithm, "MD5"))
+ {
+ /*
+ * RFC 2617 Digest with MD5
+ */
+
+ hashalg = "md5";
+ }
+ else if (!_cups_strcasecmp(http->algorithm, "SHA-256"))
+ {
+ /*
+ * RFC 7616 Digest with SHA-256
+ */
+
+ hashalg = "sha2-256";
+ }
+ else
+ {
+ /*
+ * Some other algorithm we don't support, skip this one...
+ */
+
+ return (0);
+ }
+
+ /*
+ * Calculate digest value...
+ */
+
+ /* H(A1) = H(username:realm:password) */
+ snprintf(temp, sizeof(temp), "%s:%s:%s", username, http->realm, password);
+ hashsize = (size_t)cupsHashData(hashalg, (unsigned char *)temp, strlen(temp), hash, sizeof(hash));
+ cupsHashString(hash, hashsize, ha1, sizeof(ha1));
+
+ /* H(A2) = H(method:uri) */
+ snprintf(temp, sizeof(temp), "%s:%s", method, resource);
+ hashsize = (size_t)cupsHashData(hashalg, (unsigned char *)temp, strlen(temp), hash, sizeof(hash));
+ cupsHashString(hash, hashsize, ha2, sizeof(ha2));
+
+ /* KD = H(H(A1):nonce:nc:cnonce:qop:H(A2)) */
+ snprintf(temp, sizeof(temp), "%s:%s:%08x:%s:%s:%s", ha1, http->nonce, http->nonce_count, cnonce, "auth", ha2);
+ hashsize = (size_t)cupsHashData(hashalg, (unsigned char *)temp, strlen(temp), hash, sizeof(hash));
+ cupsHashString(hash, hashsize, kd, sizeof(kd));
+
+ /*
+ * Pass the RFC 2617/7616 WWW-Authenticate header...
+ */
+
+ if (http->opaque[0])
+ snprintf(digest, sizeof(digest), "username=\"%s\", realm=\"%s\", nonce=\"%s\", algorithm=%s, qop=auth, opaque=\"%s\", cnonce=\"%s\", nc=%08x, uri=\"%s\", response=\"%s\"", cupsUser(), http->realm, http->nonce, http->algorithm, http->opaque, cnonce, http->nonce_count, resource, kd);
+ else
+ snprintf(digest, sizeof(digest), "username=\"%s\", realm=\"%s\", nonce=\"%s\", algorithm=%s, qop=auth, cnonce=\"%s\", nc=%08x, uri=\"%s\", response=\"%s\"", username, http->realm, http->nonce, http->algorithm, cnonce, http->nonce_count, resource, kd);
+ }
+ else
+ {
+ /*
+ * Use old RFC 2069 Digest method...
+ */
+
+ /* H(A1) = H(username:realm:password) */
+ snprintf(temp, sizeof(temp), "%s:%s:%s", username, http->realm, password);
+ hashsize = (size_t)cupsHashData("md5", (unsigned char *)temp, strlen(temp), hash, sizeof(hash));
+ cupsHashString(hash, hashsize, ha1, sizeof(ha1));
+
+ /* H(A2) = H(method:uri) */
+ snprintf(temp, sizeof(temp), "%s:%s", method, resource);
+ hashsize = (size_t)cupsHashData("md5", (unsigned char *)temp, strlen(temp), hash, sizeof(hash));
+ cupsHashString(hash, hashsize, ha2, sizeof(ha2));
+
+ /* KD = H(H(A1):nonce:H(A2)) */
+ snprintf(temp, sizeof(temp), "%s:%s:%s", ha1, http->nonce, ha2);
+ hashsize = (size_t)cupsHashData("md5", (unsigned char *)temp, strlen(temp), hash, sizeof(hash));
+ cupsHashString(hash, hashsize, kd, sizeof(kd));
+
+ /*
+ * Pass the old RFC 2069 WWW-Authenticate header...
+ */
+
+ snprintf(digest, sizeof(digest), "username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", response=\"%s\"", username, http->realm, http->nonce, resource, kd);
+ }
+
+ httpSetAuthString(http, "Digest", digest);
+
+ return (1);
+}
+
+