Additional comment changes for reformat of 1.0.1
[openssl.git] / engines / e_capi.c
index 4245a37d5f3c7a586f2f7eb6e8dfe2f69c4dc0f2..c1085b56cdabc46d0b46eef62481cab50500be46 100644 (file)
 
 #include <stdio.h>
 #include <string.h>
-#include <windows.h>
-#include <wincrypt.h>
 #include <openssl/crypto.h>
 #include <openssl/buffer.h>
-#include <openssl/engine.h>
-#include <openssl/rsa.h>
 #include <openssl/bn.h>
-#include <openssl/pem.h>
 
 #ifdef OPENSSL_SYS_WIN32
 #ifndef OPENSSL_NO_CAPIENG
 
+#include <openssl/rsa.h>
+
+#include <windows.h>
+
 #ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x400
+#define _WIN32_WINNT 0x0400
 #endif
 
+#include <wincrypt.h>
+
+/*
+ * This module uses several "new" interfaces, among which is
+ * CertGetCertificateContextProperty. CERT_KEY_PROV_INFO_PROP_ID is
+ * one of possible values you can pass to function in question. By
+ * checking if it's defined we can see if wincrypt.h and accompanying
+ * crypt32.lib are in shape. The native MingW32 headers up to and
+ * including __W32API_VERSION 3.14 lack of struct DSSPUBKEY and the
+ * defines CERT_STORE_PROV_SYSTEM_A and CERT_STORE_READONLY_FLAG,
+ * so we check for these too and avoid compiling.
+ * Yes, it's rather "weak" test and if compilation fails,
+ * then re-configure with -DOPENSSL_NO_CAPIENG.
+ */
+#if defined(CERT_KEY_PROV_INFO_PROP_ID) && \
+    defined(CERT_STORE_PROV_SYSTEM_A) && \
+    defined(CERT_STORE_READONLY_FLAG)
+# define __COMPILE_CAPIENG
+#endif /* CERT_KEY_PROV_INFO_PROP_ID */
+#endif /* OPENSSL_NO_CAPIENG */
+#endif /* OPENSSL_SYS_WIN32 */
+
+#ifdef __COMPILE_CAPIENG
+
+#undef X509_EXTENSIONS
+#undef X509_CERT_PAIR
+
+/* Definitions which may be missing from earlier version of headers */
+#ifndef CERT_STORE_OPEN_EXISTING_FLAG
+#define CERT_STORE_OPEN_EXISTING_FLAG                   0x00004000
+#endif
+
+#ifndef CERT_STORE_CREATE_NEW_FLAG
+#define CERT_STORE_CREATE_NEW_FLAG                      0x00002000
+#endif
+
+#ifndef CERT_SYSTEM_STORE_CURRENT_USER
+#define CERT_SYSTEM_STORE_CURRENT_USER                 0x00010000
+#endif 
+
+#include <openssl/engine.h>
+#include <openssl/pem.h>
+#include <openssl/x509v3.h>
 
 #include "e_capi_err.h"
 #include "e_capi_err.c"
@@ -112,7 +154,17 @@ static int capi_dsa_free(DSA *dsa);
 static int capi_load_ssl_client_cert(ENGINE *e, SSL *ssl,
        STACK_OF(X509_NAME) *ca_dn, X509 **pcert, EVP_PKEY **pkey,
        STACK_OF(X509) **pother, UI_METHOD *ui_method, void *callback_data);
-       
+
+static int cert_select_simple(ENGINE *e, SSL *ssl, STACK_OF(X509) *certs);
+#ifdef OPENSSL_CAPIENG_DIALOG
+static int cert_select_dialog(ENGINE *e, SSL *ssl, STACK_OF(X509) *certs);
+#endif
+
+typedef PCCERT_CONTEXT (WINAPI *CERTDLG)(HCERTSTORE, HWND, LPCWSTR,
+                                               LPCWSTR, DWORD, DWORD,
+                                               void *);
+typedef HWND (WINAPI *GETCONSWIN)(void);
+
 /* This structure contains CAPI ENGINE specific data:
  * it contains various global options and affects how
  * other functions behave.
@@ -126,19 +178,21 @@ struct CAPI_CTX_st {
        char *debug_file;
        /* Parameters to use for container lookup */
        DWORD keytype;
-       LPTSTR cspname;
+       LPSTR cspname;
        DWORD csptype;
        /* Certificate store name to use */
-       LPTSTR storename;
-       LPTSTR ssl_client_store;
+       LPSTR storename;
+       LPSTR ssl_client_store;
+       /* System store flags */
+       DWORD store_flags;
 
 /* Lookup string meanings in load_private_key */
 /* Substring of subject: uses "storename" */
-#define CAPI_LU_SUBSTR         0
+#define CAPI_LU_SUBSTR         1
 /* Friendly name: uses storename */
-#define CAPI_LU_FNAME          1
+#define CAPI_LU_FNAME          2
 /* Container name: uses cspname, keytype */
-#define CAPI_LU_CONTNAME       2
+#define CAPI_LU_CONTNAME       3
        int lookup_method;
 /* Info to dump with dumpcerts option */
 /* Issuer and serial name strings */
@@ -155,6 +209,10 @@ struct CAPI_CTX_st {
 #define CAPI_DMP_PKEYINFO      0x20
 
        DWORD dump_flags;
+       int (*client_cert_select)(ENGINE *e, SSL *ssl, STACK_OF(X509) *certs);
+
+       CERTDLG certselectdlg;
+       GETCONSWIN getconswindow;
 };
 
 
@@ -176,6 +234,7 @@ static int capi_ctx_set_provname_idx(CAPI_CTX *ctx, int idx);
 #define CAPI_CMD_LIST_OPTIONS          (ENGINE_CMD_BASE + 10)
 #define CAPI_CMD_LOOKUP_METHOD         (ENGINE_CMD_BASE + 11)
 #define CAPI_CMD_STORE_NAME            (ENGINE_CMD_BASE + 12)
+#define CAPI_CMD_STORE_FLAGS           (ENGINE_CMD_BASE + 13)
 
 static const ENGINE_CMD_DEFN capi_cmd_defns[] = {
        {CAPI_CMD_LIST_CERTS,
@@ -231,6 +290,10 @@ static const ENGINE_CMD_DEFN capi_cmd_defns[] = {
                "store_name",
                "certificate store name, default \"MY\"",
                ENGINE_CMD_FLAG_STRING},
+       {CAPI_CMD_STORE_FLAGS,
+               "store_flags",
+               "Certificate store flags: 1 = system store",
+               ENGINE_CMD_FLAG_NUMERIC},
 
        {0, NULL, NULL, 0}
        };
@@ -238,6 +301,7 @@ static const ENGINE_CMD_DEFN capi_cmd_defns[] = {
 static int capi_idx = -1;
 static int rsa_capi_idx = -1;
 static int dsa_capi_idx = -1;
+static int cert_capi_idx = -1;
 
 static int capi_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
        {
@@ -276,6 +340,20 @@ static int capi_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
                CAPI_trace(ctx, "Setting store name to %s\n", p);
                break;
 
+               case CAPI_CMD_STORE_FLAGS:
+               if (i & 1)
+                       {
+                       ctx->store_flags |= CERT_SYSTEM_STORE_LOCAL_MACHINE;
+                       ctx->store_flags &= ~CERT_SYSTEM_STORE_CURRENT_USER;
+                       }
+               else
+                       {
+                       ctx->store_flags |= CERT_SYSTEM_STORE_CURRENT_USER;
+                       ctx->store_flags &= ~CERT_SYSTEM_STORE_LOCAL_MACHINE;
+                       }
+               CAPI_trace(ctx, "Setting flags to %d\n", i);
+               break;
+
                case CAPI_CMD_DEBUG_LEVEL:
                ctx->debug_level = (int)i;
                CAPI_trace(ctx, "Setting debug level to %d\n", ctx->debug_level);
@@ -364,27 +442,50 @@ static int capi_init(ENGINE *e)
        CAPI_CTX *ctx;
        const RSA_METHOD *ossl_rsa_meth;
        const DSA_METHOD *ossl_dsa_meth;
-       capi_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL, 0);
+
+       if (capi_idx < 0)
+               {
+               capi_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL, 0);
+               if (capi_idx < 0)
+                       goto memerr;
+
+               cert_capi_idx = X509_get_ex_new_index(0, NULL, NULL, NULL, 0);
+
+               /* Setup RSA_METHOD */
+               rsa_capi_idx = RSA_get_ex_new_index(0, NULL, NULL, NULL, 0);
+               ossl_rsa_meth = RSA_PKCS1_SSLeay();
+               capi_rsa_method.rsa_pub_enc = ossl_rsa_meth->rsa_pub_enc;
+               capi_rsa_method.rsa_pub_dec = ossl_rsa_meth->rsa_pub_dec;
+               capi_rsa_method.rsa_mod_exp = ossl_rsa_meth->rsa_mod_exp;
+               capi_rsa_method.bn_mod_exp = ossl_rsa_meth->bn_mod_exp;
+
+               /* Setup DSA Method */
+               dsa_capi_idx = DSA_get_ex_new_index(0, NULL, NULL, NULL, 0);
+               ossl_dsa_meth = DSA_OpenSSL();
+               capi_dsa_method.dsa_do_verify = ossl_dsa_meth->dsa_do_verify;
+               capi_dsa_method.dsa_mod_exp = ossl_dsa_meth->dsa_mod_exp;
+               capi_dsa_method.bn_mod_exp = ossl_dsa_meth->bn_mod_exp;
+               }
 
        ctx = capi_ctx_new();
-       if (!ctx || (capi_idx < 0))
+       if (!ctx)
                goto memerr;
 
        ENGINE_set_ex_data(e, capi_idx, ctx);
-       /* Setup RSA_METHOD */
-       rsa_capi_idx = RSA_get_ex_new_index(0, NULL, NULL, NULL, 0);
-       ossl_rsa_meth = RSA_PKCS1_SSLeay();
-       capi_rsa_method.rsa_pub_enc = ossl_rsa_meth->rsa_pub_enc;
-       capi_rsa_method.rsa_pub_dec = ossl_rsa_meth->rsa_pub_dec;
-       capi_rsa_method.rsa_mod_exp = ossl_rsa_meth->rsa_mod_exp;
-       capi_rsa_method.bn_mod_exp = ossl_rsa_meth->bn_mod_exp;
-
-       /* Setup DSA Method */
-       dsa_capi_idx = DSA_get_ex_new_index(0, NULL, NULL, NULL, 0);
-       ossl_dsa_meth = DSA_OpenSSL();
-       capi_dsa_method.dsa_do_verify = ossl_dsa_meth->dsa_do_verify;
-       capi_dsa_method.dsa_mod_exp = ossl_dsa_meth->dsa_mod_exp;
-       capi_dsa_method.bn_mod_exp = ossl_dsa_meth->bn_mod_exp;
+
+#ifdef OPENSSL_CAPIENG_DIALOG
+       {
+       HMODULE cryptui = LoadLibrary(TEXT("CRYPTUI.DLL"));
+       HMODULE kernel = GetModuleHandle(TEXT("KERNEL32.DLL"));
+       if (cryptui)
+               ctx->certselectdlg = (CERTDLG)GetProcAddress(cryptui, "CryptUIDlgSelectCertificateFromStore");
+       if (kernel)
+               ctx->getconswindow = (GETCONSWIN)GetProcAddress(kernel, "GetConsoleWindow");
+       if (cryptui && !OPENSSL_isservice())
+               ctx->client_cert_select = cert_select_dialog;
+       }
+#endif
+               
 
        return 1;
 
@@ -418,6 +519,8 @@ static int capi_finish(ENGINE *e)
 
 struct CAPI_KEY_st
        {
+       /* Associated certificate context (if any) */
+       PCCERT_CONTEXT pcert;
        HCRYPTPROV hprov;
        HCRYPTKEY key;
        DWORD keyspec;
@@ -427,6 +530,7 @@ static int bind_capi(ENGINE *e)
        {
        if (!ENGINE_set_id(e, engine_capi_id)
                || !ENGINE_set_name(e, engine_capi_name)
+               || !ENGINE_set_flags(e, ENGINE_FLAGS_NO_REGISTER_ALL)
                || !ENGINE_set_init_function(e, capi_init)
                || !ENGINE_set_finish_function(e, capi_finish)
                || !ENGINE_set_destroy_function(e, capi_destroy)
@@ -647,7 +751,7 @@ static EVP_PKEY *capi_get_pkey(ENGINE *eng, CAPI_KEY *key)
        return ret;
 
 memerr:
-       CAPIerr(CAPI_F_CAPI_LOAD_PRIVKEY, ERR_R_MALLOC_FAILURE);
+       CAPIerr(CAPI_F_CAPI_GET_PKEY, ERR_R_MALLOC_FAILURE);
        goto err;
 
        }
@@ -754,7 +858,7 @@ int capi_rsa_sign(int dtype, const unsigned char *m, unsigned int m_len,
 
 /* Finally sign it */
        slen = RSA_size(rsa);
-       if(!CryptSignHash(hash, capi_key->keyspec, NULL, 0, sigret, &slen))
+       if(!CryptSignHashA(hash, capi_key->keyspec, NULL, 0, sigret, &slen))
                {
                CAPIerr(CAPI_F_CAPI_RSA_SIGN, CAPI_R_ERROR_SIGNING_HASH);
                capi_addlasterror();
@@ -892,7 +996,7 @@ static DSA_SIG *capi_dsa_do_sign(const unsigned char *digest, int dlen,
 
        /* Finally sign it */
        slen = sizeof(csigbuf);
-       if(!CryptSignHash(hash, capi_key->keyspec, NULL, 0, csigbuf, &slen))
+       if(!CryptSignHashA(hash, capi_key->keyspec, NULL, 0, csigbuf, &slen))
                {
                CAPIerr(CAPI_F_CAPI_DSA_DO_SIGN, CAPI_R_ERROR_SIGNING_HASH);
                capi_addlasterror();
@@ -967,15 +1071,29 @@ static void capi_adderror(DWORD err)
 static char *wide_to_asc(LPWSTR wstr)
        {
        char *str;
+       int len_0,sz;
+
        if (!wstr)
                return NULL;
-       str = OPENSSL_malloc(wcslen(wstr) + 1);
+       len_0 = (int)wcslen(wstr)+1;    /* WideCharToMultiByte expects int */
+        sz = WideCharToMultiByte(CP_ACP,0,wstr,len_0,NULL,0,NULL,NULL);
+       if (!sz)
+               {
+               CAPIerr(CAPI_F_WIDE_TO_ASC, CAPI_R_WIN32_ERROR);
+               return NULL;
+               }
+       str = OPENSSL_malloc(sz);
        if (!str)
                {
                CAPIerr(CAPI_F_WIDE_TO_ASC, ERR_R_MALLOC_FAILURE);
                return NULL;
                }
-       sprintf(str, "%S", wstr);
+       if (!WideCharToMultiByte(CP_ACP,0,wstr,len_0,str,sz,NULL,NULL))
+               {
+               OPENSSL_free(str);
+               CAPIerr(CAPI_F_WIDE_TO_ASC, CAPI_R_WIN32_ERROR);
+               return NULL;
+               }
        return str;
        }
 
@@ -984,7 +1102,7 @@ static int capi_get_provname(CAPI_CTX *ctx, LPSTR *pname, DWORD *ptype, DWORD id
        LPSTR name;
        DWORD len, err;
        CAPI_trace(ctx, "capi_get_provname, index=%d\n", idx);
-       if (!CryptEnumProviders(idx, NULL, 0, ptype, NULL, &len))
+       if (!CryptEnumProvidersA(idx, NULL, 0, ptype, NULL, &len))
                {
                err = GetLastError();
                if (err == ERROR_NO_MORE_ITEMS)
@@ -994,7 +1112,7 @@ static int capi_get_provname(CAPI_CTX *ctx, LPSTR *pname, DWORD *ptype, DWORD id
                return 0;
                }
        name = OPENSSL_malloc(len);
-               if (!CryptEnumProviders(idx, NULL, 0, ptype, name, &len))
+       if (!CryptEnumProvidersA(idx, NULL, 0, ptype, name, &len))
                {
                err = GetLastError();
                if (err == ERROR_NO_MORE_ITEMS)
@@ -1013,7 +1131,7 @@ static int capi_list_providers(CAPI_CTX *ctx, BIO *out)
        {
        DWORD idx, ptype;
        int ret;
-       LPTSTR provname = NULL;
+       LPSTR provname = NULL;
        CAPI_trace(ctx, "capi_list_providers\n");
        BIO_printf(out, "Available CSPs:\n");
        for(idx = 0; ; idx++)
@@ -1036,7 +1154,7 @@ static int capi_list_containers(CAPI_CTX *ctx, BIO *out)
        DWORD err, idx, flags, buflen = 0, clen;
        LPSTR cname;
        CAPI_trace(ctx, "Listing containers CSP=%s, type = %d\n", ctx->cspname, ctx->csptype);
-       if (!CryptAcquireContext(&hprov, NULL, ctx->cspname, ctx->csptype, CRYPT_VERIFYCONTEXT))
+       if (!CryptAcquireContextA(&hprov, NULL, ctx->cspname, ctx->csptype, CRYPT_VERIFYCONTEXT))
                {
                CAPIerr(CAPI_F_CAPI_LIST_CONTAINERS, CAPI_R_CRYPTACQUIRECONTEXT_ERROR);
                capi_addlasterror();
@@ -1046,6 +1164,7 @@ static int capi_list_containers(CAPI_CTX *ctx, BIO *out)
                {
                CAPIerr(CAPI_F_CAPI_LIST_CONTAINERS, CAPI_R_ENUMCONTAINERS_ERROR);
                capi_addlasterror();
+               CryptReleaseContext(hprov, 0);
                return 0;
                }
        CAPI_trace(ctx, "Got max container len %d\n", buflen);
@@ -1222,7 +1341,8 @@ HCERTSTORE capi_open_store(CAPI_CTX *ctx, char *storename)
                storename = "MY";
        CAPI_trace(ctx, "Opening certificate store %s\n", storename);
 
-       hstore = CertOpenSystemStore(0, storename);
+       hstore = CertOpenStore(CERT_STORE_PROV_SYSTEM_A, 0, 0, 
+                               ctx->store_flags, storename);
        if (!hstore)
                {
                CAPIerr(CAPI_F_CAPI_OPEN_STORE, CAPI_R_ERROR_OPENING_STORE);
@@ -1312,10 +1432,13 @@ static PCCERT_CONTEXT capi_find_cert(CAPI_CTX *ctx, const char *id, HCERTSTORE h
 static CAPI_KEY *capi_get_key(CAPI_CTX *ctx, const char *contname, char *provname, DWORD ptype, DWORD keyspec)
        {
        CAPI_KEY *key;
+    DWORD dwFlags = 0; 
        key = OPENSSL_malloc(sizeof(CAPI_KEY));
        CAPI_trace(ctx, "capi_get_key, contname=%s, provname=%s, type=%d\n", 
                                                contname, provname, ptype);
-       if (!CryptAcquireContext(&key->hprov, contname, provname, ptype, 0))
+    if(ctx->store_flags & CERT_SYSTEM_STORE_LOCAL_MACHINE)
+        dwFlags = CRYPT_MACHINE_KEYSET;
+    if (!CryptAcquireContextA(&key->hprov, contname, provname, ptype, dwFlags)) 
                {
                CAPIerr(CAPI_F_CAPI_GET_KEY, CAPI_R_CRYPTACQUIRECONTEXT_ERROR);
                capi_addlasterror();
@@ -1329,6 +1452,7 @@ static CAPI_KEY *capi_get_key(CAPI_CTX *ctx, const char *contname, char *provnam
                goto err;
                }
        key->keyspec = keyspec;
+       key->pcert = NULL;
        return key;
 
        err:
@@ -1338,7 +1462,7 @@ static CAPI_KEY *capi_get_key(CAPI_CTX *ctx, const char *contname, char *provnam
 
 static CAPI_KEY *capi_get_cert_key(CAPI_CTX *ctx, PCCERT_CONTEXT cert)
        {
-       CAPI_KEY *key;
+       CAPI_KEY *key = NULL;
        CRYPT_KEY_PROV_INFO *pinfo = NULL;
        char *provname = NULL, *contname = NULL;
        pinfo = capi_get_prov_info(ctx, cert);
@@ -1347,8 +1471,7 @@ static CAPI_KEY *capi_get_cert_key(CAPI_CTX *ctx, PCCERT_CONTEXT cert)
        provname = wide_to_asc(pinfo->pwszProvName);
        contname = wide_to_asc(pinfo->pwszContainerName);
        if (!provname || !contname)
-               return 0;
-
+               goto err;
        key = capi_get_key(ctx, contname, provname,
                                pinfo->dwProvType, pinfo->dwKeySpec);
 
@@ -1398,6 +1521,8 @@ void capi_free_key(CAPI_KEY *key)
                return;
        CryptDestroyKey(key->key);
        CryptReleaseContext(key->hprov, 0);
+       if (key->pcert)
+               CertFreeCertificateContext(key->pcert);
        OPENSSL_free(key);
        }
 
@@ -1419,9 +1544,13 @@ static CAPI_CTX *capi_ctx_new()
        ctx->keytype = AT_KEYEXCHANGE;
        ctx->storename = NULL;
        ctx->ssl_client_store = NULL;
+       ctx->store_flags = CERT_STORE_OPEN_EXISTING_FLAG |
+                               CERT_STORE_READONLY_FLAG |
+                               CERT_SYSTEM_STORE_CURRENT_USER;
        ctx->lookup_method = CAPI_LU_SUBSTR;
        ctx->debug_level = 0;
        ctx->debug_file = NULL;
+       ctx->client_cert_select = cert_select_simple;
        return ctx;
        }
 
@@ -1447,7 +1576,7 @@ static int capi_ctx_set_provname(CAPI_CTX *ctx, LPSTR pname, DWORD type, int che
        if (check)
                {
                HCRYPTPROV hprov;
-               if (!CryptAcquireContext(&hprov, NULL, pname, type,
+               if (!CryptAcquireContextA(&hprov, NULL, pname, type,
                                                CRYPT_VERIFYCONTEXT))
                        {
                        CAPIerr(CAPI_F_CAPI_CTX_SET_PROVNAME, CAPI_R_CRYPTACQUIRECONTEXT_ERROR);
@@ -1456,6 +1585,8 @@ static int capi_ctx_set_provname(CAPI_CTX *ctx, LPSTR pname, DWORD type, int che
                        }
                CryptReleaseContext(hprov, 0);
                }
+       if (ctx->cspname)
+               OPENSSL_free(ctx->cspname);
        ctx->cspname = BUF_strdup(pname);
        ctx->csptype = type;
        return 1;
@@ -1465,9 +1596,12 @@ static int capi_ctx_set_provname_idx(CAPI_CTX *ctx, int idx)
        {
        LPSTR pname;
        DWORD type;
+       int res;
        if (capi_get_provname(ctx, &pname, &type, idx) != 1)
                return 0;
-       return capi_ctx_set_provname(ctx, pname, type, 0);
+       res = capi_ctx_set_provname(ctx, pname, type, 0);
+       OPENSSL_free(pname);
+       return res;
        }
 
 static int cert_issuer_match(STACK_OF(X509_NAME) *ca_dn, X509 *x)
@@ -1486,23 +1620,21 @@ static int cert_issuer_match(STACK_OF(X509_NAME) *ca_dn, X509 *x)
        return 0;
        }
 
+
+
 static int capi_load_ssl_client_cert(ENGINE *e, SSL *ssl,
        STACK_OF(X509_NAME) *ca_dn, X509 **pcert, EVP_PKEY **pkey,
        STACK_OF(X509) **pother, UI_METHOD *ui_method, void *callback_data)
        {
-#if 0
-       /* For now just one matching key/cert */
        STACK_OF(X509) *certs = NULL;
-       STACK_OF(EVP_PKEY) *keys = NULL;
-#endif
        X509 *x;
-       EVP_PKEY *pk;
        char *storename;
        const char *p;
-       int i;
+       int i, client_cert_idx;
        HCERTSTORE hstore;
-       PCCERT_CONTEXT cert = NULL;
+       PCCERT_CONTEXT cert = NULL, excert = NULL;
        CAPI_CTX *ctx;
+       CAPI_KEY *key;
        ctx = ENGINE_get_ex_data(e, capi_idx);
 
        *pcert = NULL;
@@ -1515,8 +1647,8 @@ static int capi_load_ssl_client_cert(ENGINE *e, SSL *ssl,
        hstore = capi_open_store(ctx, storename);
        if (!hstore)
                return 0;
-       /* Enumerate all certificates looking for a match */
-       for(i = 0;!*pcert;i++)
+       /* Enumerate all certificates collect any matches */
+       for(i = 0;;i++)
                {
                cert = CertEnumCertificatesInStore(hstore, cert);
                if (!cert)
@@ -1528,19 +1660,26 @@ static int capi_load_ssl_client_cert(ENGINE *e, SSL *ssl,
                        CAPI_trace(ctx, "Can't Parse Certificate %d\n", i);
                        continue;
                        }
-               if (cert_issuer_match(ca_dn, x))
+               if (cert_issuer_match(ca_dn, x)
+                       && X509_check_purpose(x, X509_PURPOSE_SSL_CLIENT, 0))
                        {
-                       CAPI_KEY *key = capi_get_cert_key(ctx, cert);
+                       key = capi_get_cert_key(ctx, cert);
                        if (!key)
-                               continue;
-                       pk = capi_get_pkey(e, key);
-                       if (!pk)
                                {
-                               capi_free_key(key);
+                               X509_free(x);
                                continue;
                                }
-                       *pcert = x;
-                       *pkey = pk;
+                       /* Match found: attach extra data to it so
+                        * we can retrieve the key later.
+                        */
+                       excert = CertDuplicateCertificateContext(cert);
+                       key->pcert = excert;
+                       X509_set_ex_data(x, cert_capi_idx, key);
+
+                       if (!certs)
+                               certs = sk_X509_new_null();
+
+                       sk_X509_push(certs, x);
                        }
                else
                        X509_free(x);
@@ -1549,13 +1688,155 @@ static int capi_load_ssl_client_cert(ENGINE *e, SSL *ssl,
 
        if (cert)
                CertFreeCertificateContext(cert);
+       if (hstore)
+               CertCloseStore(hstore, 0);
 
-       if (*pcert)
-               return 1;
-       else
+       if (!certs)
+               return 0;
+
+
+       /* Select the appropriate certificate */
+
+       client_cert_idx = ctx->client_cert_select(e, ssl, certs);
+
+       /* Set the selected certificate and free the rest */
+
+       for(i = 0; i < sk_X509_num(certs); i++)
+               {
+               x = sk_X509_value(certs, i);
+               if (i == client_cert_idx)
+                       *pcert = x;
+               else
+                       {
+                       key = X509_get_ex_data(x, cert_capi_idx);
+                       capi_free_key(key);
+                       X509_free(x);
+                       }
+               }
+
+       sk_X509_free(certs);
+
+       if (!*pcert)
                return 0;
 
+       /* Setup key for selected certificate */
+
+       key = X509_get_ex_data(*pcert, cert_capi_idx);
+       *pkey = capi_get_pkey(e, key);
+       X509_set_ex_data(*pcert, cert_capi_idx, NULL);
+
+       return 1;
+
        }
 
+
+/* Simple client cert selection function: always select first */
+
+static int cert_select_simple(ENGINE *e, SSL *ssl, STACK_OF(X509) *certs)
+       {
+       return 0;
+       }
+
+#ifdef OPENSSL_CAPIENG_DIALOG
+
+/* More complex cert selection function, using standard function
+ * CryptUIDlgSelectCertificateFromStore() to produce a dialog box.
+ */
+
+/* Definitions which are in cryptuiapi.h but this is not present in older
+ * versions of headers.
+ */
+
+#ifndef CRYPTUI_SELECT_LOCATION_COLUMN
+#define CRYPTUI_SELECT_LOCATION_COLUMN                   0x000000010
+#define CRYPTUI_SELECT_INTENDEDUSE_COLUMN                0x000000004
+#endif
+
+#define dlg_title L"OpenSSL Application SSL Client Certificate Selection"
+#define dlg_prompt L"Select a certificate to use for authentication"
+#define dlg_columns     CRYPTUI_SELECT_LOCATION_COLUMN \
+                       |CRYPTUI_SELECT_INTENDEDUSE_COLUMN
+
+static int cert_select_dialog(ENGINE *e, SSL *ssl, STACK_OF(X509) *certs)
+       {
+       X509 *x;
+       HCERTSTORE dstore;
+       PCCERT_CONTEXT cert;
+       CAPI_CTX *ctx;
+       CAPI_KEY *key;
+       HWND hwnd;
+       int i, idx = -1;
+       if (sk_X509_num(certs) == 1)
+               return 0;
+       ctx = ENGINE_get_ex_data(e, capi_idx);
+       /* Create an in memory store of certificates */
+       dstore = CertOpenStore(CERT_STORE_PROV_MEMORY, 0, 0,
+                                       CERT_STORE_CREATE_NEW_FLAG, NULL);
+       if (!dstore)
+               {
+               CAPIerr(CAPI_F_CERT_SELECT_DIALOG, CAPI_R_ERROR_CREATING_STORE);
+               capi_addlasterror();
+               goto err;
+               }
+       /* Add all certificates to store */
+       for(i = 0; i < sk_X509_num(certs); i++)
+               {
+               x = sk_X509_value(certs, i);
+               key = X509_get_ex_data(x, cert_capi_idx);
+
+               if (!CertAddCertificateContextToStore(dstore, key->pcert,
+                                               CERT_STORE_ADD_NEW, NULL))
+                       {
+                       CAPIerr(CAPI_F_CERT_SELECT_DIALOG, CAPI_R_ERROR_ADDING_CERT);
+                       capi_addlasterror();
+                       goto err;
+                       }
+
+               }
+       hwnd = GetForegroundWindow();
+       if (!hwnd)
+               hwnd = GetActiveWindow();
+       if (!hwnd && ctx->getconswindow)
+               hwnd = ctx->getconswindow();
+       /* Call dialog to select one */
+       cert = ctx->certselectdlg(dstore, hwnd, dlg_title, dlg_prompt,
+                                               dlg_columns, 0, NULL);
+
+       /* Find matching cert from list */
+       if (cert)
+               {
+               for(i = 0; i < sk_X509_num(certs); i++)
+                       {
+                       x = sk_X509_value(certs, i);
+                       key = X509_get_ex_data(x, cert_capi_idx);
+                       if (CertCompareCertificate(
+                               X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
+                                       cert->pCertInfo,
+                                       key->pcert->pCertInfo))
+                               {
+                               idx = i;
+                               break;
+                               }
+                       }
+               }
+
+       err:
+       if (dstore)
+               CertCloseStore(dstore, 0);
+       return idx;
+
+       }
+#endif
+
+#else /* !__COMPILE_CAPIENG */
+#include <openssl/engine.h>
+#ifndef OPENSSL_NO_DYNAMIC_ENGINE
+OPENSSL_EXPORT
+int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns);
+OPENSSL_EXPORT
+int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns) { return 0; }
+IMPLEMENT_DYNAMIC_CHECK_FN()
+#else
+void ENGINE_load_capi(void){}
 #endif
 #endif