adam@1: #include <string.h>
adam@1: 
adam@6: #include <openssl/bio.h>
adam@6: #include <openssl/evp.h>
adam@6: #include <openssl/buffer.h>
adam@0: #include <openssl/sha.h>
adam@7: #include <openssl/hmac.h>
adam@8: #include <openssl/dh.h>
adam@0: #include <curl/curl.h>
adam@1: #include <expat.h>
adam@0: 
adam@1: #include <openid.h>
adam@0: 
adam@3: #define BUF_MAX 10240
adam@3: #define BUF_INIT 1024
adam@3: 
adam@8: #define PRIME_LEN 64
adam@8: #define GENERATOR DH_GENERATOR_5
adam@2: 
adam@2: uw_Basis_string uw_OpenidFfi_endpoint(uw_context ctx, uw_OpenidFfi_discovery d) {
adam@8:   return d.endpoint;
adam@2: }
adam@2: 
adam@2: uw_Basis_string uw_OpenidFfi_localId(uw_context ctx, uw_OpenidFfi_discovery d) {
adam@8:   return d.localId;
adam@2: }
adam@2: 
adam@0: uw_unit uw_OpenidFfi_init(uw_context ctx) {
adam@0:   curl_global_init(CURL_GLOBAL_ALL);
adam@0: 
adam@0:   return uw_unit_v;
adam@0: }
adam@1: 
adam@1: static CURL *curl(uw_context ctx) {
adam@1:   CURL *r;
adam@1: 
adam@1:   if (!(r = uw_get_global(ctx, "curl"))) {
adam@1:     r = curl_easy_init();
adam@1:     if (r)
adam@1:       uw_set_global(ctx, "curl", r, curl_easy_cleanup);
adam@1:   }
adam@1: 
adam@1:   return r;
adam@1: }
adam@1: 
adam@1: typedef struct {
adam@1:   uw_context ctx;
adam@8:   uw_OpenidFfi_discovery *d;
adam@1: } endpoint;
adam@1: 
adam@1: static void XMLCALL startElement(void *userData, const XML_Char *name, const XML_Char **atts) {
adam@1:   endpoint *ep = userData;
adam@1: 
adam@1:   if (!strcmp(name, "link")) {
adam@1:     const XML_Char **attp;
adam@1:     int found = 0;
adam@1: 
adam@1:     for (attp = atts; *attp; attp += 2) {
adam@1:       if (!strcmp(attp[0], "rel") && !strcmp(attp[1], "openid2.provider")) {
adam@1:         found = 1;
adam@1:         break;
adam@1:       }
adam@1:     }
adam@1: 
adam@1:     if (found) {
adam@1:       for (attp = atts; *attp; attp += 2) {
adam@1:         if (!strcmp(attp[0], "href")) {
adam@2:           ep->d->endpoint = uw_strdup(ep->ctx, attp[1]);
adam@1:           return;
adam@1:         }
adam@1:       }
adam@1:     }
adam@1:   }
adam@1: }
adam@1: 
adam@1: typedef struct {
adam@1:   XML_Parser parser;
adam@1:   int any_errors;
adam@3: } curl_discovery_data;
adam@1: 
adam@3: static size_t write_discovery_data(void *buffer, size_t size, size_t nmemb, void *userp) {
adam@3:   curl_discovery_data *d = userp;
adam@1: 
adam@1:   if (!XML_Parse(d->parser, buffer, size * nmemb, 0))
adam@1:     d->any_errors = 1;
adam@1: 
adam@1:   return size * nmemb;
adam@1: }
adam@1: 
adam@2: uw_OpenidFfi_discovery *uw_OpenidFfi_discover(uw_context ctx, uw_Basis_string id) {
adam@1:   char *s;
adam@1:   CURL *c = curl(ctx);
adam@3:   curl_discovery_data cd = {};
adam@8:   uw_OpenidFfi_discovery *dy = uw_malloc(ctx, sizeof(uw_OpenidFfi_discovery));
adam@2:   endpoint ep = {ctx, dy};
adam@1:   CURLcode code;
adam@1: 
adam@2:   dy->endpoint = dy->localId = NULL;
adam@2: 
adam@1:   if (!strchr(id, ':')) {
adam@1:     id = uw_Basis_strcat(ctx, "http://", id);
adam@1:     if ((s = strchr(id, '#')) != NULL)
adam@1:       *s = 0;
adam@1:   } else if ((s = strchr(id, '#')) != NULL) {
adam@1:     char *id2 = uw_malloc(ctx, s - id + 1);
adam@1:     memcpy(id2, s, s - id);
adam@1:     id2[s - id] = 0;
adam@1:     id = id2;
adam@1:   }
adam@1: 
adam@1:   cd.parser = XML_ParserCreate(NULL);
adam@1:   XML_SetUserData(cd.parser, &ep);
adam@1:   uw_push_cleanup(ctx, (void (*)(void *))XML_ParserFree, cd.parser);
adam@7:   XML_SetStartElementHandler(cd.parser, startElement);
adam@1: 
adam@1:   curl_easy_setopt(c, CURLOPT_URL, id);
adam@3:   curl_easy_setopt(c, CURLOPT_WRITEFUNCTION, write_discovery_data);
adam@1:   curl_easy_setopt(c, CURLOPT_WRITEDATA, &cd);
adam@1: 
adam@1:   code = curl_easy_perform(c);
adam@1:   uw_pop_cleanup(ctx);
adam@1: 
adam@8:   if (code || !dy->endpoint)
adam@1:     return NULL;
adam@8:   else
adam@8:     return dy;
adam@1: }
adam@3: 
adam@3: uw_OpenidFfi_inputs uw_OpenidFfi_createInputs(uw_context ctx) {
adam@3:   uw_buffer *r = uw_malloc(ctx, sizeof(uw_buffer));
adam@3:   uw_buffer_init(BUF_MAX, r, BUF_INIT);
adam@3:   return r;
adam@3: }
adam@3: 
adam@8: static void postify(uw_OpenidFfi_inputs buf, uw_Basis_string s) {
adam@8:   for (; *s; ++s) {
adam@8:     switch (*s) {
adam@8:     case '=':
adam@8:       uw_buffer_append(buf, "%3D", 3);
adam@8:       break;
adam@8:     case '&':
adam@8:       uw_buffer_append(buf, "%26", 3);
adam@8:       break;
adam@8:     default:
adam@8:       uw_buffer_append(buf, s, 1);
adam@8:     }
adam@8:   }
adam@3: }
adam@3: 
adam@3: uw_unit uw_OpenidFfi_addInput(uw_context ctx, uw_OpenidFfi_inputs buf, uw_Basis_string key, uw_Basis_string value) {
adam@3:   if (uw_buffer_used(buf) > 0)
adam@3:     uw_buffer_append(buf, "&", 1);
adam@3: 
adam@8:   postify(buf, key);
adam@3:   uw_buffer_append(buf, "=", 1);
adam@8:   postify(buf, value);
adam@3: 
adam@3:   return uw_unit_v;
adam@3: }
adam@3: 
adam@3: uw_Basis_string uw_OpenidFfi_getOutput(uw_context ctx, uw_OpenidFfi_outputs buf, uw_Basis_string key) {
adam@3:   char *s = buf->start;
adam@3: 
adam@3:   for (; *s; s = strchr(strchr(s, 0)+1, 0)+1)
adam@3:     if (!strcmp(key, s))
adam@3:       return strchr(s, 0)+1;
adam@3: 
adam@3:   return NULL;
adam@3: }
adam@3: 
adam@3: static size_t write_buffer_data(void *buffer, size_t size, size_t nmemb, void *userp) {
adam@3:   uw_buffer *buf = userp;
adam@3: 
adam@3:   uw_buffer_append(buf, buffer, size * nmemb);
adam@3: 
adam@3:   return size * nmemb;
adam@3: }
adam@3: 
adam@3: const char curl_failure[] = "error\0Error fetching URL";
adam@3: 
adam@4: uw_OpenidFfi_outputs uw_OpenidFfi_direct(uw_context ctx, uw_Basis_string url, uw_OpenidFfi_inputs inps) {
adam@3:   uw_buffer *buf = uw_malloc(ctx, sizeof(uw_buffer));
adam@3:   CURL *c = curl(ctx);
adam@3:   CURLcode code;
adam@3: 
adam@3:   uw_buffer_init(BUF_MAX, buf, BUF_INIT);
adam@3: 
adam@3:   uw_buffer_append(inps, "", 1);
adam@3: 
adam@3:   curl_easy_setopt(c, CURLOPT_URL, url);
adam@3:   curl_easy_setopt(c, CURLOPT_POSTFIELDS, inps->start);
adam@3:   curl_easy_setopt(c, CURLOPT_WRITEFUNCTION, write_buffer_data);
adam@3:   curl_easy_setopt(c, CURLOPT_WRITEDATA, buf);
adam@3: 
adam@3:   code = curl_easy_perform(c);
adam@3: 
adam@3:   uw_buffer_append(buf, "", 1);
adam@3: 
adam@3:   if (code) {
adam@3:     uw_buffer_reset(buf);
adam@3:     uw_buffer_append(buf, curl_failure, sizeof curl_failure);
adam@3:   } else {
adam@3:     char *s;
adam@3: 
adam@3:     s = buf->start;
adam@3:     while (*s) {
adam@3:       char *colon = strchr(s, ':'), *newline;
adam@3: 
adam@3:       if (!colon) {
adam@3:         *s = 0;
adam@3:         break;
adam@3:       }
adam@3: 
adam@7:       *colon = 0;
adam@7: 
adam@3:       newline = strchr(colon+1, '\n');
adam@3: 
adam@7:       if (!newline)
adam@3:         break;
adam@3: 
adam@3:       *newline = 0;
adam@3:       s = newline+1;
adam@3:     }
adam@3:   }
adam@3: 
adam@3:   return buf;
adam@3: }
adam@4: 
adam@4: static uw_Basis_string deurl(uw_context ctx, uw_Basis_string s) {
adam@4:   uw_Basis_string r = uw_malloc(ctx, strlen(s)), s2 = r;
adam@4: 
adam@4:   for (; *s; ++s) {
adam@4:     if (s[0] == '%' && s[1] && s[2]) {
adam@4:       unsigned u;
adam@4: 
adam@4:       sscanf(s+1, "%02x", &u);
adam@4:       *s2++ = u;
adam@4:       s += 2;
adam@4:     } else
adam@4:       *s2++ = *s;
adam@4:   }
adam@4: 
adam@4:   *s2 = 0;
adam@4:   return r;
adam@4: }
adam@4: 
adam@4: uw_OpenidFfi_outputs uw_OpenidFfi_indirect(uw_context ctx, uw_Basis_string fields) {
adam@4:   uw_OpenidFfi_outputs b = malloc(sizeof(uw_buffer));
adam@4: 
adam@4:   uw_buffer_init(BUF_MAX, b, BUF_INIT);
adam@4: 
adam@6:   fields = uw_strdup(ctx, fields);
adam@6: 
adam@4:   while (*fields) {
adam@4:     char *equal = strchr(fields, '='), *and, *s;
adam@4: 
adam@4:     if (!equal)
adam@4:       break;
adam@4: 
adam@4:     *equal = 0;
adam@4:     s = deurl(ctx, fields);
adam@4:     uw_buffer_append(b, s, strlen(s));
adam@4:     uw_buffer_append(b, "", 1);
adam@4: 
adam@4:     and = strchr(equal+1, '&');
adam@4:     if (and) {
adam@4:       *and = 0;
adam@4:       fields = and+1;
adam@4:     } else
adam@4:       fields = and = strchr(equal+1, 0);
adam@4:     s = deurl(ctx, equal+1);
adam@4:     uw_buffer_append(b, s, strlen(s));
adam@4:     uw_buffer_append(b, "", 1);
adam@4:   }
adam@4: 
adam@4:   uw_buffer_append(b, "", 1);
adam@4:   return b;
adam@4: }
adam@6: 
adam@6: static uw_Basis_string base64(uw_context ctx, unsigned char *input, int length) {
adam@6:   BIO *bmem, *b64;
adam@6: 
adam@6:   b64 = BIO_new(BIO_f_base64());
adam@7:   BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
adam@6:   bmem = BIO_new(BIO_s_mem());
adam@7:   BIO_push(b64, bmem);
adam@6:   BIO_write(b64, input, length);
adam@6:   (void)BIO_flush(b64);
adam@6: 
adam@7:   int len = BIO_ctrl_pending(bmem);
adam@7:   char *buff = uw_malloc(ctx, len+1);
adam@7:   BIO_read(bmem, buff, len);
adam@7:   buff[len] = 0;
adam@6: 
adam@6:   BIO_free_all(b64);
adam@6: 
adam@6:   return buff;
adam@6: }
adam@6: 
adam@8: static int unbase64(unsigned char *input, int length, unsigned char *buffer, int bufferLength)
adam@7: {
adam@7:   BIO *b64, *bmem;
adam@8:   int n;
adam@6: 
adam@7:   b64 = BIO_new(BIO_f_base64());
adam@7:   BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
adam@7:   bmem = BIO_new_mem_buf(input, length);
adam@7:   BIO_push(b64, bmem);
adam@8:   n = BIO_read(b64, buffer, bufferLength);
adam@6: 
adam@7:   BIO_free_all(bmem);
adam@8: 
adam@8:   return n;
adam@8: }
adam@8: 
adam@12: uw_Basis_string uw_OpenidFfi_hmac_sha1(uw_context ctx, uw_Basis_string key, uw_Basis_string data) {
adam@8:   unsigned char keyBin[SHA_DIGEST_LENGTH], out[EVP_MAX_MD_SIZE];
adam@8:   unsigned outLen;
adam@8: 
adam@8:   unbase64((unsigned char *)key, strlen(key), keyBin, sizeof keyBin);
adam@8: 
adam@8:   HMAC(EVP_sha1(), keyBin, sizeof keyBin, (unsigned char *)data, strlen(data), out, &outLen);
adam@8:   return base64(ctx, out, outLen);
adam@6: }
adam@7: 
adam@12: uw_Basis_string uw_OpenidFfi_hmac_sha256(uw_context ctx, uw_Basis_string key, uw_Basis_string data) {
adam@7:   unsigned char keyBin[SHA256_DIGEST_LENGTH], out[EVP_MAX_MD_SIZE];
adam@7:   unsigned outLen;
adam@7: 
adam@7:   unbase64((unsigned char *)key, strlen(key), keyBin, sizeof keyBin);
adam@7: 
adam@7:   HMAC(EVP_sha256(), keyBin, sizeof keyBin, (unsigned char *)data, strlen(data), out, &outLen);
adam@7:   return base64(ctx, out, outLen);
adam@7: }
adam@8: 
adam@8: static uw_Basis_string btwoc(uw_context ctx, const BIGNUM *n) {
adam@8:   int len = BN_num_bytes(n), i;
adam@8:   unsigned char bytes[len+1];
adam@8: 
adam@8:   bytes[0] = 0;
adam@8:   BN_bn2bin(n, bytes+1);
adam@8: 
adam@8:   for (i = 1; i <= len; ++i)
adam@8:     if (bytes[i]) {
adam@8:       if (bytes[i] & 0x80)
adam@8:         --i;
adam@8:       break;
adam@8:     }
adam@8: 
adam@8:   if (i > len)
adam@8:     i = len;
adam@8: 
adam@8:   return base64(ctx, bytes+i, len+1-i);
adam@8: }
adam@8: 
adam@8: static BIGNUM *unbtwoc(uw_context ctx, uw_Basis_string s) {
adam@8:   unsigned char bytes[1024];
adam@8:   int len;
adam@8: 
adam@8:   len = unbase64((unsigned char *)s, strlen(s), bytes, sizeof bytes);
adam@8:   return BN_bin2bn(bytes, len, NULL);
adam@8: }
adam@8: 
adam@8: uw_Basis_string uw_OpenidFfi_modulus(uw_context ctx, uw_OpenidFfi_dh dh) {
adam@8:   return btwoc(ctx, dh->p);
adam@8: }
adam@8: 
adam@8: uw_Basis_string uw_OpenidFfi_generator(uw_context ctx, uw_OpenidFfi_dh dh) {
adam@8:   return btwoc(ctx, dh->g);
adam@8: }
adam@8: 
adam@8: uw_Basis_string uw_OpenidFfi_public(uw_context ctx, uw_OpenidFfi_dh dh) {
adam@8:   return btwoc(ctx, dh->pub_key);
adam@8: }
adam@8: 
adam@8: static void free_DH(void *data, int will_retry) {
adam@8:   DH *dh = data;
adam@8:   DH_free(dh);
adam@8: }
adam@8: 
adam@8: uw_OpenidFfi_dh uw_OpenidFfi_generate(uw_context ctx) {
adam@8:   DH *dh = DH_new();
adam@8: 
adam@8:   uw_register_transactional(ctx, dh, NULL, NULL, free_DH);
adam@8: 
adam@8:   DH_generate_parameters_ex(dh, PRIME_LEN, GENERATOR, NULL);
adam@8: 
adam@8:   if (DH_generate_key(dh) != 1)
adam@8:     uw_error(ctx, FATAL, "Diffie-Hellman key generation failed");
adam@8: 
adam@8:   return dh;
adam@8: }
adam@8: 
adam@8: uw_Basis_string uw_OpenidFfi_compute(uw_context ctx, uw_OpenidFfi_dh dh, uw_Basis_string server_pub) {
adam@8:   BIGNUM *bn = unbtwoc(ctx, server_pub);
adam@12:   unsigned char secret[DH_size(dh)+1], *secretP;
adam@8:   int size;
adam@8: 
adam@8:   uw_push_cleanup(ctx, (void (*)(void *))BN_free, bn);
adam@8: 
adam@12:   size = DH_compute_key(secret+1, bn, dh);
adam@8:   if (size == -1)
adam@8:     uw_error(ctx, FATAL, "Diffie-Hellman key computation failed");
adam@8: 
adam@8:   uw_pop_cleanup(ctx);
adam@8: 
adam@12:   if (size > 0 && (secret[1] & 0x80)) {
adam@12:     secret[0] = 0;
adam@12:     secretP = secret;
adam@12:     ++size;
adam@12:   } else
adam@12:     secretP = secret+1;
adam@12: 
adam@12:   return base64(ctx, secretP, size);
adam@8: }
adam@12: 
adam@12: uw_Basis_string uw_OpenidFfi_sha1(uw_context ctx, uw_Basis_string data) {
adam@12:   unsigned char dataBin[128], out[EVP_MAX_MD_SIZE];
adam@12:   int len;
adam@12: 
adam@12:   len = unbase64((unsigned char *)data, strlen(data), dataBin, sizeof dataBin);
adam@12: 
adam@12:   SHA1(dataBin, len, out);
adam@12:   return base64(ctx, out, SHA_DIGEST_LENGTH);
adam@12: }
adam@12: 
adam@12: uw_Basis_string uw_OpenidFfi_sha256(uw_context ctx, uw_Basis_string data) {
adam@12:   unsigned char dataBin[128], out[EVP_MAX_MD_SIZE];
adam@12:   int len;
adam@12: 
adam@12:   len = unbase64((unsigned char *)data, strlen(data), dataBin, sizeof dataBin);
adam@12:   
adam@12:   SHA256(dataBin, len, out);
adam@12:   return base64(ctx, out, SHA256_DIGEST_LENGTH);
adam@12: }
adam@12: 
adam@12: uw_Basis_string uw_OpenidFfi_xor(uw_context ctx, uw_Basis_string s1, uw_Basis_string s2) {
adam@12:   unsigned char buf1[128], buf2[128], bufO[128];
adam@12:   int len1, len2, i;
adam@12: 
adam@12:   len1 = unbase64((unsigned char *)s1, strlen(s1), buf1, sizeof buf1);
adam@12:   len2 = unbase64((unsigned char *)s2, strlen(s2), buf2, sizeof buf2);
adam@12: 
adam@12:   for (i = 0; i < len1; ++i)
adam@12:     bufO[i] = buf1[i] ^ buf2[i % len2];
adam@12: 
adam@12:   return base64(ctx, bufO, len1);
adam@12: }