hs20/client/est.c - third_party/hostap - Git at Google

 /*
  * Hotspot 2.0 OSU client - EST client
  * Copyright (c) 2012-2014, Qualcomm Atheros, Inc.
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
  */

 #include "includes.h"
 #include <openssl/err.h>
 #include <openssl/evp.h>
 #include <openssl/pem.h>
 #include <openssl/pkcs7.h>
 #include <openssl/rsa.h>
 #include <openssl/asn1.h>
 #include <openssl/asn1t.h>
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>

 #include "common.h"
 #include "utils/base64.h"
 #include "utils/xml-utils.h"
 #include "utils/http-utils.h"
 #include "osu_client.h"


 static int pkcs7_to_cert(struct hs20_osu_client *ctx, const u8 *pkcs7,
 			 size_t len, char *pem_file, char *der_file)
 {
 	PKCS7 *p7 = NULL;
 	const unsigned char *p = pkcs7;
 	STACK_OF(X509) *certs;
 	int i, num, ret = -1;
 	BIO *out = NULL;

 	p7 = d2i_PKCS7(NULL, &p, len);
 	if (p7 == NULL) {
 		wpa_printf(MSG_INFO, "Could not parse PKCS#7 object: %s",
 			   ERR_error_string(ERR_get_error(), NULL));
 		write_result(ctx, "Could not parse PKCS#7 object from EST");
 		goto fail;
 	}

 	switch (OBJ_obj2nid(p7->type)) {
 	case NID_pkcs7_signed:
 		certs = p7->d.sign->cert;
 		break;
 	case NID_pkcs7_signedAndEnveloped:
 		certs = p7->d.signed_and_enveloped->cert;
 		break;
 	default:
 		certs = NULL;
 		break;
 	}

 	if (!certs || ((num = sk_X509_num(certs)) == 0)) {
 		wpa_printf(MSG_INFO, "No certificates found in PKCS#7 object");
 		write_result(ctx, "No certificates found in PKCS#7 object");
 		goto fail;
 	}

 	if (der_file) {
 		FILE *f = fopen(der_file, "wb");
 		if (f == NULL)
 			goto fail;
 		i2d_X509_fp(f, sk_X509_value(certs, 0));
 		fclose(f);
 	}

 	if (pem_file) {
 		out = BIO_new(BIO_s_file());
 		if (out == NULL ||
 		    BIO_write_filename(out, pem_file) <= 0)
 			goto fail;

 		for (i = 0; i < num; i++) {
 			X509 *cert = sk_X509_value(certs, i);
 			X509_print(out, cert);
 			PEM_write_bio_X509(out, cert);
 			BIO_puts(out, "\n");
 		}
 	}

 	ret = 0;

 fail:
 	PKCS7_free(p7);
 	if (out)
 		BIO_free_all(out);

 	return ret;
 }


 int est_load_cacerts(struct hs20_osu_client *ctx, const char *url)
 {
 	char *buf, *resp;
 	size_t buflen;
 	unsigned char *pkcs7;
 	size_t pkcs7_len, resp_len;
 	int res;

 	buflen = os_strlen(url) + 100;
 	buf = os_malloc(buflen);
 	if (buf == NULL)
 		return -1;

 	os_snprintf(buf, buflen, "%s/cacerts", url);
 	wpa_printf(MSG_INFO, "Download EST cacerts from %s", buf);
 	write_summary(ctx, "Download EST cacerts from %s", buf);
 	ctx->no_osu_cert_validation = 1;
 	http_ocsp_set(ctx->http, 1);
 	res = http_download_file(ctx->http, buf, "Cert/est-cacerts.txt",
 				 ctx->ca_fname);
 	http_ocsp_set(ctx->http,
 		      (ctx->workarounds & WORKAROUND_OCSP_OPTIONAL) ? 1 : 2);
 	ctx->no_osu_cert_validation = 0;
 	if (res < 0) {
 		wpa_printf(MSG_INFO, "Failed to download EST cacerts from %s",
 			   buf);
 		write_result(ctx, "Failed to download EST cacerts from %s",
 			     buf);
 		os_free(buf);
 		return -1;
 	}
 	os_free(buf);

 	resp = os_readfile("Cert/est-cacerts.txt", &resp_len);
 	if (resp == NULL) {
 		wpa_printf(MSG_INFO, "Could not read Cert/est-cacerts.txt");
 		write_result(ctx, "Could not read EST cacerts");
 		return -1;
 	}

 	pkcs7 = base64_decode((unsigned char *) resp, resp_len, &pkcs7_len);
 	if (pkcs7 && pkcs7_len < resp_len / 2) {
 		wpa_printf(MSG_INFO, "Too short base64 decode (%u bytes; downloaded %u bytes) - assume this was binary",
 			   (unsigned int) pkcs7_len, (unsigned int) resp_len);
 		os_free(pkcs7);
 		pkcs7 = NULL;
 	}
 	if (pkcs7 == NULL) {
 		wpa_printf(MSG_INFO, "EST workaround - Could not decode base64, assume this is DER encoded PKCS7");
 		pkcs7 = os_malloc(resp_len);
 		if (pkcs7) {
 			os_memcpy(pkcs7, resp, resp_len);
 			pkcs7_len = resp_len;
 		}
 	}
 	os_free(resp);

 	if (pkcs7 == NULL) {
 		wpa_printf(MSG_INFO, "Could not fetch PKCS7 cacerts");
 		write_result(ctx, "Could not fetch EST PKCS#7 cacerts");
 		return -1;
 	}

 	res = pkcs7_to_cert(ctx, pkcs7, pkcs7_len, "Cert/est-cacerts.pem",
 			    NULL);
 	os_free(pkcs7);
 	if (res < 0) {
 		wpa_printf(MSG_INFO, "Could not parse CA certs from PKCS#7 cacerts response");
 		write_result(ctx, "Could not parse CA certs from EST PKCS#7 cacerts response");
 		return -1;
 	}
 	unlink("Cert/est-cacerts.txt");

 	return 0;
 }


 /*
  * CsrAttrs ::= SEQUENCE SIZE (0..MAX) OF AttrOrOID
  *
  * AttrOrOID ::= CHOICE {
  *   oid OBJECT IDENTIFIER,
  *   attribute Attribute }
  *
  * Attribute ::= SEQUENCE {
  *   type OBJECT IDENTIFIER,
  *   values SET SIZE(1..MAX) OF OBJECT IDENTIFIER }
  */

 typedef struct {
 	ASN1_OBJECT *type;
 	STACK_OF(ASN1_OBJECT) *values;
 } Attribute;

 typedef struct {
 	int type;
 	union {
 		ASN1_OBJECT *oid;
 		Attribute *attribute;
 	} d;
 } AttrOrOID;

 typedef struct {
 	int type;
 	STACK_OF(AttrOrOID) *attrs;
 } CsrAttrs;

 ASN1_SEQUENCE(Attribute) = {
 	ASN1_SIMPLE(Attribute, type, ASN1_OBJECT),
 	ASN1_SET_OF(Attribute, values, ASN1_OBJECT)
 } ASN1_SEQUENCE_END(Attribute);

 ASN1_CHOICE(AttrOrOID) = {
 	ASN1_SIMPLE(AttrOrOID, d.oid, ASN1_OBJECT),
 	ASN1_SIMPLE(AttrOrOID, d.attribute, Attribute)
 } ASN1_CHOICE_END(AttrOrOID);

 ASN1_CHOICE(CsrAttrs) = {
 	ASN1_SEQUENCE_OF(CsrAttrs, attrs, AttrOrOID)
 } ASN1_CHOICE_END(CsrAttrs);

 IMPLEMENT_ASN1_FUNCTIONS(CsrAttrs);


 static void add_csrattrs_oid(struct hs20_osu_client *ctx, ASN1_OBJECT *oid,
 			     STACK_OF(X509_EXTENSION) *exts)
 {
 	char txt[100];
 	int res;

 	if (!oid)
 		return;

 	res = OBJ_obj2txt(txt, sizeof(txt), oid, 1);
 	if (res < 0 || res >= (int) sizeof(txt))
 		return;

 	if (os_strcmp(txt, "1.2.840.113549.1.9.7") == 0) {
 		wpa_printf(MSG_INFO, "TODO: csrattr challengePassword");
 	} else if (os_strcmp(txt, "1.2.840.113549.1.1.11") == 0) {
 		wpa_printf(MSG_INFO, "csrattr sha256WithRSAEncryption");
 	} else {
 		wpa_printf(MSG_INFO, "Ignore unsupported csrattr oid %s", txt);
 	}
 }


 static void add_csrattrs_ext_req(struct hs20_osu_client *ctx,
 				 STACK_OF(ASN1_OBJECT) *values,
 				 STACK_OF(X509_EXTENSION) *exts)
 {
 	char txt[100];
 	int i, num, res;

 	num = sk_ASN1_OBJECT_num(values);
 	for (i = 0; i < num; i++) {
 		ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(values, i);

 		res = OBJ_obj2txt(txt, sizeof(txt), oid, 1);
 		if (res < 0 || res >= (int) sizeof(txt))
 			continue;

 		if (os_strcmp(txt, "1.3.6.1.1.1.1.22") == 0) {
 			wpa_printf(MSG_INFO, "TODO: extReq macAddress");
 		} else if (os_strcmp(txt, "1.3.6.1.4.1.40808.1.1.3") == 0) {
 			wpa_printf(MSG_INFO, "TODO: extReq imei");
 		} else if (os_strcmp(txt, "1.3.6.1.4.1.40808.1.1.4") == 0) {
 			wpa_printf(MSG_INFO, "TODO: extReq meid");
 		} else if (os_strcmp(txt, "1.3.6.1.4.1.40808.1.1.5") == 0) {
 			wpa_printf(MSG_INFO, "TODO: extReq DevId");
 		} else {
 			wpa_printf(MSG_INFO, "Ignore unsupported cstattr extensionsRequest %s",
 				   txt);
 		}
 	}
 }


 static void add_csrattrs_attr(struct hs20_osu_client *ctx, Attribute *attr,
 			      STACK_OF(X509_EXTENSION) *exts)
 {
 	char txt[100], txt2[100];
 	int i, num, res;

 	if (!attr || !attr->type || !attr->values)
 		return;

 	res = OBJ_obj2txt(txt, sizeof(txt), attr->type, 1);
 	if (res < 0 || res >= (int) sizeof(txt))
 		return;

 	if (os_strcmp(txt, "1.2.840.113549.1.9.14") == 0) {
 		add_csrattrs_ext_req(ctx, attr->values, exts);
 		return;
 	}

 	num = sk_ASN1_OBJECT_num(attr->values);
 	for (i = 0; i < num; i++) {
 		ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(attr->values, i);

 		res = OBJ_obj2txt(txt2, sizeof(txt2), oid, 1);
 		if (res < 0 || res >= (int) sizeof(txt2))
 			continue;

 		wpa_printf(MSG_INFO, "Ignore unsupported cstattr::attr %s oid %s",
 			   txt, txt2);
 	}
 }


 static void add_csrattrs(struct hs20_osu_client *ctx, CsrAttrs *csrattrs,
 			 STACK_OF(X509_EXTENSION) *exts)
 {
 	int i, num;

 	if (!csrattrs || ! csrattrs->attrs)
 		return;

 	num = SKM_sk_num(AttrOrOID, csrattrs->attrs);
 	for (i = 0; i < num; i++) {
 		AttrOrOID *ao = SKM_sk_value(AttrOrOID, csrattrs->attrs, i);
 		switch (ao->type) {
 		case 0:
 			add_csrattrs_oid(ctx, ao->d.oid, exts);
 			break;
 		case 1:
 			add_csrattrs_attr(ctx, ao->d.attribute, exts);
 			break;
 		}
 	}
 }


 static int generate_csr(struct hs20_osu_client *ctx, char *key_pem,
 			char *csr_pem, char *est_req, char *old_cert,
 			CsrAttrs *csrattrs)
 {
 	EVP_PKEY_CTX *pctx = NULL;
 	EVP_PKEY *pkey = NULL;
 	RSA *rsa;
 	X509_REQ *req = NULL;
 	int ret = -1;
 	unsigned int val;
 	X509_NAME *subj = NULL;
 	char name[100];
 	STACK_OF(X509_EXTENSION) *exts = NULL;
 	X509_EXTENSION *ex;
 	BIO *out;

 	wpa_printf(MSG_INFO, "Generate RSA private key");
 	write_summary(ctx, "Generate RSA private key");
 	pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
 	if (!pctx)
 		return -1;

 	if (EVP_PKEY_keygen_init(pctx) <= 0)
 		goto fail;

 	if (EVP_PKEY_CTX_set_rsa_keygen_bits(pctx, 2048) <= 0)
 		goto fail;

 	if (EVP_PKEY_keygen(pctx, &pkey) <= 0)
 		goto fail;
 	EVP_PKEY_CTX_free(pctx);
 	pctx = NULL;

 	rsa = EVP_PKEY_get1_RSA(pkey);
 	if (rsa == NULL)
 		goto fail;

 	if (key_pem) {
 		FILE *f = fopen(key_pem, "wb");
 		if (f == NULL)
 			goto fail;
 		if (!PEM_write_RSAPrivateKey(f, rsa, NULL, NULL, 0, NULL,
 					     NULL)) {
 			wpa_printf(MSG_INFO, "Could not write private key: %s",
 				   ERR_error_string(ERR_get_error(), NULL));
 			fclose(f);
 			goto fail;
 		}
 		fclose(f);
 	}

 	wpa_printf(MSG_INFO, "Generate CSR");
 	write_summary(ctx, "Generate CSR");
 	req = X509_REQ_new();
 	if (req == NULL)
 		goto fail;

 	if (old_cert) {
 		FILE *f;
 		X509 *cert;
 		int res;

 		f = fopen(old_cert, "r");
 		if (f == NULL)
 			goto fail;
 		cert = PEM_read_X509(f, NULL, NULL, NULL);
 		fclose(f);

 		if (cert == NULL)
 			goto fail;
 		res = X509_REQ_set_subject_name(req,
 						X509_get_subject_name(cert));
 		X509_free(cert);
 		if (!res)
 			goto fail;
 	} else {
 		os_get_random((u8 *) &val, sizeof(val));
 		os_snprintf(name, sizeof(name), "cert-user-%u", val);
 		subj = X509_NAME_new();
 		if (subj == NULL ||
 		    !X509_NAME_add_entry_by_txt(subj, "CN", MBSTRING_ASC,
 						(unsigned char *) name,
 						-1, -1, 0) ||
 		    !X509_REQ_set_subject_name(req, subj))
 			goto fail;
 		X509_NAME_free(subj);
 		subj = NULL;
 	}

 	if (!X509_REQ_set_pubkey(req, pkey))
 		goto fail;

 	exts = sk_X509_EXTENSION_new_null();
 	if (!exts)
 		goto fail;

 	ex = X509V3_EXT_conf_nid(NULL, NULL, NID_basic_constraints,
 				 "CA:FALSE");
 	if (ex == NULL ||
 	    !sk_X509_EXTENSION_push(exts, ex))
 		goto fail;

 	ex = X509V3_EXT_conf_nid(NULL, NULL, NID_key_usage,
 				 "nonRepudiation,digitalSignature,keyEncipherment");
 	if (ex == NULL ||
 	    !sk_X509_EXTENSION_push(exts, ex))
 		goto fail;

 	ex = X509V3_EXT_conf_nid(NULL, NULL, NID_ext_key_usage,
 				 "1.3.6.1.4.1.40808.1.1.2");
 	if (ex == NULL ||
 	    !sk_X509_EXTENSION_push(exts, ex))
 		goto fail;

 	add_csrattrs(ctx, csrattrs, exts);

 	if (!X509_REQ_add_extensions(req, exts))
 		goto fail;
 	sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
 	exts = NULL;

 	if (!X509_REQ_sign(req, pkey, EVP_sha256()))
 		goto fail;

 	out = BIO_new(BIO_s_mem());
 	if (out) {
 		char *txt;
 		size_t rlen;

 		X509_REQ_print(out, req);
 		rlen = BIO_ctrl_pending(out);
 		txt = os_malloc(rlen + 1);
 		if (txt) {
 			int res = BIO_read(out, txt, rlen);
 			if (res > 0) {
 				txt[res] = '\0';
 				wpa_printf(MSG_MSGDUMP, "OpenSSL: Certificate request:\n%s",
 					   txt);
 			}
 			os_free(txt);
 		}
 		BIO_free(out);
 	}

 	if (csr_pem) {
 		FILE *f = fopen(csr_pem, "w");
 		if (f == NULL)
 			goto fail;
 		X509_REQ_print_fp(f, req);
 		if (!PEM_write_X509_REQ(f, req)) {
 			fclose(f);
 			goto fail;
 		}
 		fclose(f);
 	}

 	if (est_req) {
 		BIO *mem = BIO_new(BIO_s_mem());
 		BUF_MEM *ptr;
 		char *pos, *end, *buf_end;
 		FILE *f;

 		if (mem == NULL)
 			goto fail;
 		if (!PEM_write_bio_X509_REQ(mem, req)) {
 			BIO_free(mem);
 			goto fail;
 		}

 		BIO_get_mem_ptr(mem, &ptr);
 		pos = ptr->data;
 		buf_end = pos + ptr->length;

 		/* Remove START/END lines */
 		while (pos < buf_end && *pos != '\n')
 			pos++;
 		if (pos == buf_end) {
 			BIO_free(mem);
 			goto fail;
 		}
 		pos++;

 		end = pos;
 		while (end < buf_end && *end != '-')
 			end++;

 		f = fopen(est_req, "w");
 		if (f == NULL) {
 			BIO_free(mem);
 			goto fail;
 		}
 		fwrite(pos, end - pos, 1, f);
 		fclose(f);

 		BIO_free(mem);
 	}

 	ret = 0;
 fail:
 	if (exts)
 		sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
 	if (subj)
 		X509_NAME_free(subj);
 	if (req)
 		X509_REQ_free(req);
 	if (pkey)
 		EVP_PKEY_free(pkey);
 	if (pctx)
 		EVP_PKEY_CTX_free(pctx);
 	return ret;
 }


 int est_build_csr(struct hs20_osu_client *ctx, const char *url)
 {
 	char *buf;
 	size_t buflen;
 	int res;
 	char old_cert_buf[200];
 	char *old_cert = NULL;
 	CsrAttrs *csrattrs = NULL;

 	buflen = os_strlen(url) + 100;
 	buf = os_malloc(buflen);
 	if (buf == NULL)
 		return -1;

 	os_snprintf(buf, buflen, "%s/csrattrs", url);
 	wpa_printf(MSG_INFO, "Download csrattrs from %s", buf);
 	write_summary(ctx, "Download EST csrattrs from %s", buf);
 	ctx->no_osu_cert_validation = 1;
 	http_ocsp_set(ctx->http, 1);
 	res = http_download_file(ctx->http, buf, "Cert/est-csrattrs.txt",
 				 ctx->ca_fname);
 	http_ocsp_set(ctx->http,
 		      (ctx->workarounds & WORKAROUND_OCSP_OPTIONAL) ? 1 : 2);
 	ctx->no_osu_cert_validation = 0;
 	os_free(buf);
 	if (res < 0) {
 		wpa_printf(MSG_INFO, "Failed to download EST csrattrs - assume no extra attributes are needed");
 	} else {
 		size_t resp_len;
 		char *resp;
 		unsigned char *attrs;
 		const unsigned char *pos;
 		size_t attrs_len;

 		resp = os_readfile("Cert/est-csrattrs.txt", &resp_len);
 		if (resp == NULL) {
 			wpa_printf(MSG_INFO, "Could not read csrattrs");
 			return -1;
 		}

 		attrs = base64_decode((unsigned char *) resp, resp_len,
 				      &attrs_len);
 		os_free(resp);

 		if (attrs == NULL) {
 			wpa_printf(MSG_INFO, "Could not base64 decode csrattrs");
 			return -1;
 		}
 		unlink("Cert/est-csrattrs.txt");

 		pos = attrs;
 		csrattrs = d2i_CsrAttrs(NULL, &pos, attrs_len);
 		os_free(attrs);
 		if (csrattrs == NULL) {
 			wpa_printf(MSG_INFO, "Failed to parse csrattrs ASN.1");
 			/* Continue assuming no additional requirements */
 		}
 	}

 	if (ctx->client_cert_present) {
 		os_snprintf(old_cert_buf, sizeof(old_cert_buf),
 			    "SP/%s/client-cert.pem", ctx->fqdn);
 		old_cert = old_cert_buf;
 	}

 	res = generate_csr(ctx, "Cert/privkey-plain.pem", "Cert/est-req.pem",
 			   "Cert/est-req.b64", old_cert, csrattrs);
 	if (csrattrs)
 		CsrAttrs_free(csrattrs);

 	return res;
 }


 int est_simple_enroll(struct hs20_osu_client *ctx, const char *url,
 		      const char *user, const char *pw)
 {
 	char *buf, *resp, *req, *req2;
 	size_t buflen, resp_len, len, pkcs7_len;
 	unsigned char *pkcs7;
 	FILE *f;
 	char client_cert_buf[200];
 	char client_key_buf[200];
 	const char *client_cert = NULL, *client_key = NULL;
 	int res;

 	req = os_readfile("Cert/est-req.b64", &len);
 	if (req == NULL) {
 		wpa_printf(MSG_INFO, "Could not read Cert/req.b64");
 		return -1;
 	}
 	req2 = os_realloc(req, len + 1);
 	if (req2 == NULL) {
 		os_free(req);
 		return -1;
 	}
 	req2[len] = '\0';
 	req = req2;
 	wpa_printf(MSG_DEBUG, "EST simpleenroll request: %s", req);

 	buflen = os_strlen(url) + 100;
 	buf = os_malloc(buflen);
 	if (buf == NULL) {
 		os_free(req);
 		return -1;
 	}

 	if (ctx->client_cert_present) {
 		os_snprintf(buf, buflen, "%s/simplereenroll", url);
 		os_snprintf(client_cert_buf, sizeof(client_cert_buf),
 			    "SP/%s/client-cert.pem", ctx->fqdn);
 		client_cert = client_cert_buf;
 		os_snprintf(client_key_buf, sizeof(client_key_buf),
 			    "SP/%s/client-key.pem", ctx->fqdn);
 		client_key = client_key_buf;
 	} else
 		os_snprintf(buf, buflen, "%s/simpleenroll", url);
 	wpa_printf(MSG_INFO, "EST simpleenroll URL: %s", buf);
 	write_summary(ctx, "EST simpleenroll URL: %s", buf);
 	ctx->no_osu_cert_validation = 1;
 	http_ocsp_set(ctx->http, 1);
 	resp = http_post(ctx->http, buf, req, "application/pkcs10",
 			 "Content-Transfer-Encoding: base64",
 			 ctx->ca_fname, user, pw, client_cert, client_key,
 			 &resp_len);
 	http_ocsp_set(ctx->http,
 		      (ctx->workarounds & WORKAROUND_OCSP_OPTIONAL) ? 1 : 2);
 	ctx->no_osu_cert_validation = 0;
 	os_free(buf);
 	if (resp == NULL) {
 		wpa_printf(MSG_INFO, "EST certificate enrollment failed");
 		write_result(ctx, "EST certificate enrollment failed");
 		return -1;
 	}
 	wpa_printf(MSG_DEBUG, "EST simpleenroll response: %s", resp);
 	f = fopen("Cert/est-resp.raw", "w");
 	if (f) {
 		fwrite(resp, resp_len, 1, f);
 		fclose(f);
 	}

 	pkcs7 = base64_decode((unsigned char *) resp, resp_len, &pkcs7_len);
 	if (pkcs7 == NULL) {
 		wpa_printf(MSG_INFO, "EST workaround - Could not decode base64, assume this is DER encoded PKCS7");
 		pkcs7 = os_malloc(resp_len);
 		if (pkcs7) {
 			os_memcpy(pkcs7, resp, resp_len);
 			pkcs7_len = resp_len;
 		}
 	}
 	os_free(resp);

 	if (pkcs7 == NULL) {
 		wpa_printf(MSG_INFO, "Failed to parse simpleenroll base64 response");
 		write_result(ctx, "Failed to parse EST simpleenroll base64 response");
 		return -1;
 	}

 	res = pkcs7_to_cert(ctx, pkcs7, pkcs7_len, "Cert/est_cert.pem",
 			    "Cert/est_cert.der");
 	os_free(pkcs7);

 	if (res < 0) {
 		wpa_printf(MSG_INFO, "EST: Failed to extract certificate from PKCS7 file");
 		write_result(ctx, "EST: Failed to extract certificate from EST PKCS7 file");
 		return -1;
 	}

 	wpa_printf(MSG_INFO, "EST simple%senroll completed successfully",
 		   ctx->client_cert_present ? "re" : "");
 	write_summary(ctx, "EST simple%senroll completed successfully",
 		      ctx->client_cert_present ? "re" : "");

 	return 0;
 }
	/*
	* Hotspot 2.0 OSU client - EST client
	* Copyright (c) 2012-2014, Qualcomm Atheros, Inc.
	*
	* This software may be distributed under the terms of the BSD license.
	* See README for more details.
	*/

	#include "includes.h"
	#include <openssl/err.h>
	#include <openssl/evp.h>
	#include <openssl/pem.h>
	#include <openssl/pkcs7.h>
	#include <openssl/rsa.h>
	#include <openssl/asn1.h>
	#include <openssl/asn1t.h>
	#include <openssl/x509.h>
	#include <openssl/x509v3.h>

	#include "common.h"
	#include "utils/base64.h"
	#include "utils/xml-utils.h"
	#include "utils/http-utils.h"
	#include "osu_client.h"


	static int pkcs7_to_cert(struct hs20_osu_client ctx, const u8 pkcs7,
	size_t len, char pem_file, char der_file)
	{
	PKCS7 *p7 = NULL;
	const unsigned char *p = pkcs7;
	STACK_OF(X509) *certs;
	int i, num, ret = -1;
	BIO *out = NULL;

	p7 = d2i_PKCS7(NULL, &p, len);
	if (p7 == NULL) {
	wpa_printf(MSG_INFO, "Could not parse PKCS#7 object: %s",
	ERR_error_string(ERR_get_error(), NULL));
	write_result(ctx, "Could not parse PKCS#7 object from EST");
	goto fail;
	}

	switch (OBJ_obj2nid(p7->type)) {
	case NID_pkcs7_signed:
	certs = p7->d.sign->cert;
	break;
	case NID_pkcs7_signedAndEnveloped:
	certs = p7->d.signed_and_enveloped->cert;
	break;
	default:
	certs = NULL;
	break;
	}

	if (!certs \|\| ((num = sk_X509_num(certs)) == 0)) {
	wpa_printf(MSG_INFO, "No certificates found in PKCS#7 object");
	write_result(ctx, "No certificates found in PKCS#7 object");
	goto fail;
	}

	if (der_file) {
	FILE *f = fopen(der_file, "wb");
	if (f == NULL)
	goto fail;
	i2d_X509_fp(f, sk_X509_value(certs, 0));
	fclose(f);
	}

	if (pem_file) {
	out = BIO_new(BIO_s_file());
	if (out == NULL \|\|
	BIO_write_filename(out, pem_file) <= 0)
	goto fail;

	for (i = 0; i < num; i++) {
	X509 *cert = sk_X509_value(certs, i);
	X509_print(out, cert);
	PEM_write_bio_X509(out, cert);
	BIO_puts(out, "\n");
	}
	}

	ret = 0;

	fail:
	PKCS7_free(p7);
	if (out)
	BIO_free_all(out);

	return ret;
	}


	int est_load_cacerts(struct hs20_osu_client ctx, const char url)
	{
	char buf, resp;
	size_t buflen;
	unsigned char *pkcs7;
	size_t pkcs7_len, resp_len;
	int res;

	buflen = os_strlen(url) + 100;
	buf = os_malloc(buflen);
	if (buf == NULL)
	return -1;

	os_snprintf(buf, buflen, "%s/cacerts", url);
	wpa_printf(MSG_INFO, "Download EST cacerts from %s", buf);
	write_summary(ctx, "Download EST cacerts from %s", buf);
	ctx->no_osu_cert_validation = 1;
	http_ocsp_set(ctx->http, 1);
	res = http_download_file(ctx->http, buf, "Cert/est-cacerts.txt",
	ctx->ca_fname);
	http_ocsp_set(ctx->http,
	(ctx->workarounds & WORKAROUND_OCSP_OPTIONAL) ? 1 : 2);
	ctx->no_osu_cert_validation = 0;
	if (res < 0) {
	wpa_printf(MSG_INFO, "Failed to download EST cacerts from %s",
	buf);
	write_result(ctx, "Failed to download EST cacerts from %s",
	buf);
	os_free(buf);
	return -1;
	}
	os_free(buf);

	resp = os_readfile("Cert/est-cacerts.txt", &resp_len);
	if (resp == NULL) {
	wpa_printf(MSG_INFO, "Could not read Cert/est-cacerts.txt");
	write_result(ctx, "Could not read EST cacerts");
	return -1;
	}

	pkcs7 = base64_decode((unsigned char *) resp, resp_len, &pkcs7_len);
	if (pkcs7 && pkcs7_len < resp_len / 2) {
	wpa_printf(MSG_INFO, "Too short base64 decode (%u bytes; downloaded %u bytes) - assume this was binary",
	(unsigned int) pkcs7_len, (unsigned int) resp_len);
	os_free(pkcs7);
	pkcs7 = NULL;
	}
	if (pkcs7 == NULL) {
	wpa_printf(MSG_INFO, "EST workaround - Could not decode base64, assume this is DER encoded PKCS7");
	pkcs7 = os_malloc(resp_len);
	if (pkcs7) {
	os_memcpy(pkcs7, resp, resp_len);
	pkcs7_len = resp_len;
	}
	}
	os_free(resp);

	if (pkcs7 == NULL) {
	wpa_printf(MSG_INFO, "Could not fetch PKCS7 cacerts");
	write_result(ctx, "Could not fetch EST PKCS#7 cacerts");
	return -1;
	}

	res = pkcs7_to_cert(ctx, pkcs7, pkcs7_len, "Cert/est-cacerts.pem",
	NULL);
	os_free(pkcs7);
	if (res < 0) {
	wpa_printf(MSG_INFO, "Could not parse CA certs from PKCS#7 cacerts response");
	write_result(ctx, "Could not parse CA certs from EST PKCS#7 cacerts response");
	return -1;
	}
	unlink("Cert/est-cacerts.txt");

	return 0;
	}


	/*
	* CsrAttrs ::= SEQUENCE SIZE (0..MAX) OF AttrOrOID
	*
	* AttrOrOID ::= CHOICE {
	* oid OBJECT IDENTIFIER,
	* attribute Attribute }
	*
	* Attribute ::= SEQUENCE {
	* type OBJECT IDENTIFIER,
	* values SET SIZE(1..MAX) OF OBJECT IDENTIFIER }
	*/

	typedef struct {
	ASN1_OBJECT *type;
	STACK_OF(ASN1_OBJECT) *values;
	} Attribute;

	typedef struct {
	int type;
	union {
	ASN1_OBJECT *oid;
	Attribute *attribute;
	} d;
	} AttrOrOID;

	typedef struct {
	int type;
	STACK_OF(AttrOrOID) *attrs;
	} CsrAttrs;

	ASN1_SEQUENCE(Attribute) = {
	ASN1_SIMPLE(Attribute, type, ASN1_OBJECT),
	ASN1_SET_OF(Attribute, values, ASN1_OBJECT)
	} ASN1_SEQUENCE_END(Attribute);

	ASN1_CHOICE(AttrOrOID) = {
	ASN1_SIMPLE(AttrOrOID, d.oid, ASN1_OBJECT),
	ASN1_SIMPLE(AttrOrOID, d.attribute, Attribute)
	} ASN1_CHOICE_END(AttrOrOID);

	ASN1_CHOICE(CsrAttrs) = {
	ASN1_SEQUENCE_OF(CsrAttrs, attrs, AttrOrOID)
	} ASN1_CHOICE_END(CsrAttrs);

	IMPLEMENT_ASN1_FUNCTIONS(CsrAttrs);


	static void add_csrattrs_oid(struct hs20_osu_client ctx, ASN1_OBJECT oid,
	STACK_OF(X509_EXTENSION) *exts)
	{
	char txt[100];
	int res;

	if (!oid)
	return;

	res = OBJ_obj2txt(txt, sizeof(txt), oid, 1);
	if (res < 0 \|\| res >= (int) sizeof(txt))
	return;

	if (os_strcmp(txt, "1.2.840.113549.1.9.7") == 0) {
	wpa_printf(MSG_INFO, "TODO: csrattr challengePassword");
	} else if (os_strcmp(txt, "1.2.840.113549.1.1.11") == 0) {
	wpa_printf(MSG_INFO, "csrattr sha256WithRSAEncryption");
	} else {
	wpa_printf(MSG_INFO, "Ignore unsupported csrattr oid %s", txt);
	}
	}


	static void add_csrattrs_ext_req(struct hs20_osu_client *ctx,
	STACK_OF(ASN1_OBJECT) *values,
	STACK_OF(X509_EXTENSION) *exts)
	{
	char txt[100];
	int i, num, res;

	num = sk_ASN1_OBJECT_num(values);
	for (i = 0; i < num; i++) {
	ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(values, i);

	res = OBJ_obj2txt(txt, sizeof(txt), oid, 1);
	if (res < 0 \|\| res >= (int) sizeof(txt))
	continue;

	if (os_strcmp(txt, "1.3.6.1.1.1.1.22") == 0) {
	wpa_printf(MSG_INFO, "TODO: extReq macAddress");
	} else if (os_strcmp(txt, "1.3.6.1.4.1.40808.1.1.3") == 0) {
	wpa_printf(MSG_INFO, "TODO: extReq imei");
	} else if (os_strcmp(txt, "1.3.6.1.4.1.40808.1.1.4") == 0) {
	wpa_printf(MSG_INFO, "TODO: extReq meid");
	} else if (os_strcmp(txt, "1.3.6.1.4.1.40808.1.1.5") == 0) {
	wpa_printf(MSG_INFO, "TODO: extReq DevId");
	} else {
	wpa_printf(MSG_INFO, "Ignore unsupported cstattr extensionsRequest %s",
	txt);
	}
	}
	}


	static void add_csrattrs_attr(struct hs20_osu_client ctx, Attribute attr,
	STACK_OF(X509_EXTENSION) *exts)
	{
	char txt[100], txt2[100];
	int i, num, res;

	if (!attr \|\| !attr->type \|\| !attr->values)
	return;

	res = OBJ_obj2txt(txt, sizeof(txt), attr->type, 1);
	if (res < 0 \|\| res >= (int) sizeof(txt))
	return;

	if (os_strcmp(txt, "1.2.840.113549.1.9.14") == 0) {
	add_csrattrs_ext_req(ctx, attr->values, exts);
	return;
	}

	num = sk_ASN1_OBJECT_num(attr->values);
	for (i = 0; i < num; i++) {
	ASN1_OBJECT *oid = sk_ASN1_OBJECT_value(attr->values, i);

	res = OBJ_obj2txt(txt2, sizeof(txt2), oid, 1);
	if (res < 0 \|\| res >= (int) sizeof(txt2))
	continue;

	wpa_printf(MSG_INFO, "Ignore unsupported cstattr::attr %s oid %s",
	txt, txt2);
	}
	}


	static void add_csrattrs(struct hs20_osu_client ctx, CsrAttrs csrattrs,
	STACK_OF(X509_EXTENSION) *exts)
	{
	int i, num;

	if (!csrattrs \|\| ! csrattrs->attrs)
	return;

	num = SKM_sk_num(AttrOrOID, csrattrs->attrs);
	for (i = 0; i < num; i++) {
	AttrOrOID *ao = SKM_sk_value(AttrOrOID, csrattrs->attrs, i);
	switch (ao->type) {
	case 0:
	add_csrattrs_oid(ctx, ao->d.oid, exts);
	break;
	case 1:
	add_csrattrs_attr(ctx, ao->d.attribute, exts);
	break;
	}
	}
	}


	static int generate_csr(struct hs20_osu_client ctx, char key_pem,
	char csr_pem, char est_req, char *old_cert,
	CsrAttrs *csrattrs)
	{
	EVP_PKEY_CTX *pctx = NULL;
	EVP_PKEY *pkey = NULL;
	RSA *rsa;
	X509_REQ *req = NULL;
	int ret = -1;
	unsigned int val;
	X509_NAME *subj = NULL;
	char name[100];
	STACK_OF(X509_EXTENSION) *exts = NULL;
	X509_EXTENSION *ex;
	BIO *out;

	wpa_printf(MSG_INFO, "Generate RSA private key");
	write_summary(ctx, "Generate RSA private key");
	pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
	if (!pctx)
	return -1;

	if (EVP_PKEY_keygen_init(pctx) <= 0)
	goto fail;

	if (EVP_PKEY_CTX_set_rsa_keygen_bits(pctx, 2048) <= 0)
	goto fail;

	if (EVP_PKEY_keygen(pctx, &pkey) <= 0)
	goto fail;
	EVP_PKEY_CTX_free(pctx);
	pctx = NULL;

	rsa = EVP_PKEY_get1_RSA(pkey);
	if (rsa == NULL)
	goto fail;

	if (key_pem) {
	FILE *f = fopen(key_pem, "wb");
	if (f == NULL)
	goto fail;
	if (!PEM_write_RSAPrivateKey(f, rsa, NULL, NULL, 0, NULL,
	NULL)) {
	wpa_printf(MSG_INFO, "Could not write private key: %s",
	ERR_error_string(ERR_get_error(), NULL));
	fclose(f);
	goto fail;
	}
	fclose(f);
	}

	wpa_printf(MSG_INFO, "Generate CSR");
	write_summary(ctx, "Generate CSR");
	req = X509_REQ_new();
	if (req == NULL)
	goto fail;

	if (old_cert) {
	FILE *f;
	X509 *cert;
	int res;

	f = fopen(old_cert, "r");
	if (f == NULL)
	goto fail;
	cert = PEM_read_X509(f, NULL, NULL, NULL);
	fclose(f);

	if (cert == NULL)
	goto fail;
	res = X509_REQ_set_subject_name(req,
	X509_get_subject_name(cert));
	X509_free(cert);
	if (!res)
	goto fail;
	} else {
	os_get_random((u8 *) &val, sizeof(val));
	os_snprintf(name, sizeof(name), "cert-user-%u", val);
	subj = X509_NAME_new();
	if (subj == NULL \|\|
	!X509_NAME_add_entry_by_txt(subj, "CN", MBSTRING_ASC,
	(unsigned char *) name,
	-1, -1, 0) \|\|
	!X509_REQ_set_subject_name(req, subj))
	goto fail;
	X509_NAME_free(subj);
	subj = NULL;
	}

	if (!X509_REQ_set_pubkey(req, pkey))
	goto fail;

	exts = sk_X509_EXTENSION_new_null();
	if (!exts)
	goto fail;

	ex = X509V3_EXT_conf_nid(NULL, NULL, NID_basic_constraints,
	"CA:FALSE");
	if (ex == NULL \|\|
	!sk_X509_EXTENSION_push(exts, ex))
	goto fail;

	ex = X509V3_EXT_conf_nid(NULL, NULL, NID_key_usage,
	"nonRepudiation,digitalSignature,keyEncipherment");
	if (ex == NULL \|\|
	!sk_X509_EXTENSION_push(exts, ex))
	goto fail;

	ex = X509V3_EXT_conf_nid(NULL, NULL, NID_ext_key_usage,
	"1.3.6.1.4.1.40808.1.1.2");
	if (ex == NULL \|\|
	!sk_X509_EXTENSION_push(exts, ex))
	goto fail;

	add_csrattrs(ctx, csrattrs, exts);

	if (!X509_REQ_add_extensions(req, exts))
	goto fail;
	sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
	exts = NULL;

	if (!X509_REQ_sign(req, pkey, EVP_sha256()))
	goto fail;

	out = BIO_new(BIO_s_mem());
	if (out) {
	char *txt;
	size_t rlen;

	X509_REQ_print(out, req);
	rlen = BIO_ctrl_pending(out);
	txt = os_malloc(rlen + 1);
	if (txt) {
	int res = BIO_read(out, txt, rlen);
	if (res > 0) {
	txt[res] = '\0';
	wpa_printf(MSG_MSGDUMP, "OpenSSL: Certificate request:\n%s",
	txt);
	}
	os_free(txt);
	}
	BIO_free(out);
	}

	if (csr_pem) {
	FILE *f = fopen(csr_pem, "w");
	if (f == NULL)
	goto fail;
	X509_REQ_print_fp(f, req);
	if (!PEM_write_X509_REQ(f, req)) {
	fclose(f);
	goto fail;
	}
	fclose(f);
	}

	if (est_req) {
	BIO *mem = BIO_new(BIO_s_mem());
	BUF_MEM *ptr;
	char pos, end, *buf_end;
	FILE *f;

	if (mem == NULL)
	goto fail;
	if (!PEM_write_bio_X509_REQ(mem, req)) {
	BIO_free(mem);
	goto fail;
	}

	BIO_get_mem_ptr(mem, &ptr);
	pos = ptr->data;
	buf_end = pos + ptr->length;

	/* Remove START/END lines */
	while (pos < buf_end && *pos != '\n')
	pos++;
	if (pos == buf_end) {
	BIO_free(mem);
	goto fail;
	}
	pos++;

	end = pos;
	while (end < buf_end && *end != '-')
	end++;

	f = fopen(est_req, "w");
	if (f == NULL) {
	BIO_free(mem);
	goto fail;
	}
	fwrite(pos, end - pos, 1, f);
	fclose(f);

	BIO_free(mem);
	}

	ret = 0;
	fail:
	if (exts)
	sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
	if (subj)
	X509_NAME_free(subj);
	if (req)
	X509_REQ_free(req);
	if (pkey)
	EVP_PKEY_free(pkey);
	if (pctx)
	EVP_PKEY_CTX_free(pctx);
	return ret;
	}


	int est_build_csr(struct hs20_osu_client ctx, const char url)
	{
	char *buf;
	size_t buflen;
	int res;
	char old_cert_buf[200];
	char *old_cert = NULL;
	CsrAttrs *csrattrs = NULL;

	buflen = os_strlen(url) + 100;
	buf = os_malloc(buflen);
	if (buf == NULL)
	return -1;

	os_snprintf(buf, buflen, "%s/csrattrs", url);
	wpa_printf(MSG_INFO, "Download csrattrs from %s", buf);
	write_summary(ctx, "Download EST csrattrs from %s", buf);
	ctx->no_osu_cert_validation = 1;
	http_ocsp_set(ctx->http, 1);
	res = http_download_file(ctx->http, buf, "Cert/est-csrattrs.txt",
	ctx->ca_fname);
	http_ocsp_set(ctx->http,
	(ctx->workarounds & WORKAROUND_OCSP_OPTIONAL) ? 1 : 2);
	ctx->no_osu_cert_validation = 0;
	os_free(buf);
	if (res < 0) {
	wpa_printf(MSG_INFO, "Failed to download EST csrattrs - assume no extra attributes are needed");
	} else {
	size_t resp_len;
	char *resp;
	unsigned char *attrs;
	const unsigned char *pos;
	size_t attrs_len;

	resp = os_readfile("Cert/est-csrattrs.txt", &resp_len);
	if (resp == NULL) {
	wpa_printf(MSG_INFO, "Could not read csrattrs");
	return -1;
	}

	attrs = base64_decode((unsigned char *) resp, resp_len,
	&attrs_len);
	os_free(resp);

	if (attrs == NULL) {
	wpa_printf(MSG_INFO, "Could not base64 decode csrattrs");
	return -1;
	}
	unlink("Cert/est-csrattrs.txt");

	pos = attrs;
	csrattrs = d2i_CsrAttrs(NULL, &pos, attrs_len);
	os_free(attrs);
	if (csrattrs == NULL) {
	wpa_printf(MSG_INFO, "Failed to parse csrattrs ASN.1");
	/* Continue assuming no additional requirements */
	}
	}

	if (ctx->client_cert_present) {
	os_snprintf(old_cert_buf, sizeof(old_cert_buf),
	"SP/%s/client-cert.pem", ctx->fqdn);
	old_cert = old_cert_buf;
	}

	res = generate_csr(ctx, "Cert/privkey-plain.pem", "Cert/est-req.pem",
	"Cert/est-req.b64", old_cert, csrattrs);
	if (csrattrs)
	CsrAttrs_free(csrattrs);

	return res;
	}


	int est_simple_enroll(struct hs20_osu_client ctx, const char url,
	const char user, const char pw)
	{
	char buf, resp, req, req2;
	size_t buflen, resp_len, len, pkcs7_len;
	unsigned char *pkcs7;
	FILE *f;
	char client_cert_buf[200];
	char client_key_buf[200];
	const char client_cert = NULL, client_key = NULL;
	int res;

	req = os_readfile("Cert/est-req.b64", &len);
	if (req == NULL) {
	wpa_printf(MSG_INFO, "Could not read Cert/req.b64");
	return -1;
	}
	req2 = os_realloc(req, len + 1);
	if (req2 == NULL) {
	os_free(req);
	return -1;
	}
	req2[len] = '\0';
	req = req2;
	wpa_printf(MSG_DEBUG, "EST simpleenroll request: %s", req);

	buflen = os_strlen(url) + 100;
	buf = os_malloc(buflen);
	if (buf == NULL) {
	os_free(req);
	return -1;
	}

	if (ctx->client_cert_present) {
	os_snprintf(buf, buflen, "%s/simplereenroll", url);
	os_snprintf(client_cert_buf, sizeof(client_cert_buf),
	"SP/%s/client-cert.pem", ctx->fqdn);
	client_cert = client_cert_buf;
	os_snprintf(client_key_buf, sizeof(client_key_buf),
	"SP/%s/client-key.pem", ctx->fqdn);
	client_key = client_key_buf;
	} else
	os_snprintf(buf, buflen, "%s/simpleenroll", url);
	wpa_printf(MSG_INFO, "EST simpleenroll URL: %s", buf);
	write_summary(ctx, "EST simpleenroll URL: %s", buf);
	ctx->no_osu_cert_validation = 1;
	http_ocsp_set(ctx->http, 1);
	resp = http_post(ctx->http, buf, req, "application/pkcs10",
	"Content-Transfer-Encoding: base64",
	ctx->ca_fname, user, pw, client_cert, client_key,
	&resp_len);
	http_ocsp_set(ctx->http,
	(ctx->workarounds & WORKAROUND_OCSP_OPTIONAL) ? 1 : 2);
	ctx->no_osu_cert_validation = 0;
	os_free(buf);
	if (resp == NULL) {
	wpa_printf(MSG_INFO, "EST certificate enrollment failed");
	write_result(ctx, "EST certificate enrollment failed");
	return -1;
	}
	wpa_printf(MSG_DEBUG, "EST simpleenroll response: %s", resp);
	f = fopen("Cert/est-resp.raw", "w");
	if (f) {
	fwrite(resp, resp_len, 1, f);
	fclose(f);
	}

	pkcs7 = base64_decode((unsigned char *) resp, resp_len, &pkcs7_len);
	if (pkcs7 == NULL) {
	wpa_printf(MSG_INFO, "EST workaround - Could not decode base64, assume this is DER encoded PKCS7");
	pkcs7 = os_malloc(resp_len);
	if (pkcs7) {
	os_memcpy(pkcs7, resp, resp_len);
	pkcs7_len = resp_len;
	}
	}
	os_free(resp);

	if (pkcs7 == NULL) {
	wpa_printf(MSG_INFO, "Failed to parse simpleenroll base64 response");
	write_result(ctx, "Failed to parse EST simpleenroll base64 response");
	return -1;
	}

	res = pkcs7_to_cert(ctx, pkcs7, pkcs7_len, "Cert/est_cert.pem",
	"Cert/est_cert.der");
	os_free(pkcs7);

	if (res < 0) {
	wpa_printf(MSG_INFO, "EST: Failed to extract certificate from PKCS7 file");
	write_result(ctx, "EST: Failed to extract certificate from EST PKCS7 file");
	return -1;
	}

	wpa_printf(MSG_INFO, "EST simple%senroll completed successfully",
	ctx->client_cert_present ? "re" : "");
	write_summary(ctx, "EST simple%senroll completed successfully",
	ctx->client_cert_present ? "re" : "");

	return 0;
	}