PR: 1794

Submitted by: Peter Sylvester <peter.sylvester@edelweb.fr>
Reviewed by: steve

Remove unnecessary code for srp and to add some comments to
s_client.

- the callback to provide a user during client connect is
no longer necessary since rfc 5054 a connection attempt
with an srp cipher and no user is terminated when the
cipher is acceptable

- comments to indicate in s_client the (non-)usefulness of
th primalaty tests for non known group parameters.

apps/s_client.c

@@ -403,18 +403,18 @@ typedef struct srp_arg_st
 
 #define SRP_NUMBER_ITERATIONS_FOR_PRIME 64
 
-static int SRP_Verify_N_and_g(const BIGNUM *N, const BIGNUM *g)
+static int srp_Verify_N_and_g(const BIGNUM *N, const BIGNUM *g)
 	{
 	BN_CTX *bn_ctx = BN_CTX_new();
 	BIGNUM *p = BN_new();
 	BIGNUM *r = BN_new();
 	int ret =
 		g != NULL && N != NULL && bn_ctx != NULL && BN_is_odd(N) &&
-		BN_is_prime_ex(N,SRP_NUMBER_ITERATIONS_FOR_PRIME,bn_ctx,NULL) &&
+		BN_is_prime_ex(N, SRP_NUMBER_ITERATIONS_FOR_PRIME, bn_ctx, NULL) &&
 		p != NULL && BN_rshift1(p, N) &&
 
 		/* p = (N-1)/2 */
-		BN_is_prime_ex(p,SRP_NUMBER_ITERATIONS_FOR_PRIME,bn_ctx,NULL) &&
+		BN_is_prime_ex(p, SRP_NUMBER_ITERATIONS_FOR_PRIME, bn_ctx, NULL) &&
 		r != NULL &&
 
 		/* verify g^((N-1)/2) == -1 (mod N) */
@@ -431,6 +431,21 @@ static int SRP_Verify_N_and_g(const BIGNUM *N, const BIGNUM *g)
 	return ret;
 	}
 
+/* This callback is used here for two purposes:
+   - extended debugging
+   - making some primality tests for unknown groups
+   The callback is only called for a non default group.
+
+   An application does not need the call back at all if
+   only the stanard groups are used.  In real life situations, 
+   client and server already share well known groups, 
+   thus there is no need to verify them. 
+   Furthermore, in case that a server actually proposes a group that
+   is not one of those defined in RFC 5054, it is more appropriate 
+   to add the group to a static list and then compare since 
+   primality tests are rather cpu consuming.
+*/
+
 static int MS_CALLBACK ssl_srp_verify_param_cb(SSL *s, void *arg)
 	{
 	SRP_ARG *srp_arg = (SRP_ARG *)arg;
@@ -453,11 +468,11 @@ static int MS_CALLBACK ssl_srp_verify_param_cb(SSL *s, void *arg)
 		if (srp_arg->debug)
 			BIO_printf(bio_err, "SRP param N and g are not known params, going to check deeper.\n");
 
-/* The srp_moregroups must be used with caution, testing primes costs time. 
+/* The srp_moregroups is a real debugging feature.
    Implementors should rather add the value to the known ones.
    The minimal size has already been tested.
 */
-		if (BN_num_bits(g) <= BN_BITS && SRP_Verify_N_and_g(N,g))
+		if (BN_num_bits(g) <= BN_BITS && srp_Verify_N_and_g(N,g))
 			return 1;
 		}	
 	BIO_printf(bio_err, "SRP param N and g rejected.\n");
@@ -486,12 +501,6 @@ static char * MS_CALLBACK ssl_give_srp_client_pwd_cb(SSL *s, void *arg)
 	return pass;
 	}
 
-static char * MS_CALLBACK missing_srp_username_callback(SSL *s, void *arg)
-	{
-	SRP_ARG *srp_arg = (SRP_ARG *)arg;
-	return BUF_strdup(srp_arg->srplogin);
-	}
-
 #endif
 	char *srtp_profiles = NULL;
 
@@ -1182,9 +1191,7 @@ bad:
 #ifndef OPENSSL_NO_SRP
         if (srp_arg.srplogin)
 		{
-		if (srp_lateuser) 
-			SSL_CTX_set_srp_missing_srp_username_callback(ctx,missing_srp_username_callback);
-		else if (!SSL_CTX_set_srp_username(ctx, srp_arg.srplogin))
+		if (!srp_lateuser && !SSL_CTX_set_srp_username(ctx, srp_arg.srplogin))
 			{
 			BIO_printf(bio_err,"Unable to set SRP username\n");
 			goto end;

crypto/symhacks.h

@@ -202,9 +202,6 @@
 #define SSL_CTX_set_srp_verify_param_callback	SSL_CTX_set_srp_vfy_param_cb
 #undef SSL_CTX_set_srp_username_callback
 #define SSL_CTX_set_srp_username_callback	SSL_CTX_set_srp_un_cb
-#undef SSL_CTX_set_srp_missing_srp_username_callback
-#define SSL_CTX_set_srp_missing_srp_username_callback \
-						SSL_CTX_set_srp_miss_srp_un_cb
 
 /* Hack some long ENGINE names */
 #undef ENGINE_get_default_BN_mod_exp_crt

ssl/s3_lib.c

@@ -3679,10 +3679,6 @@ long ssl3_ctx_callback_ctrl(SSL_CTX *ctx, int cmd, void (*fp)(void))
 		ctx->srp_ctx.srp_Mask|=SSL_kSRP;
 		ctx->srp_ctx.SRP_give_srp_client_pwd_callback=(char *(*)(SSL *,void *))fp;
 		break;
-	case SSL_CTRL_SET_TLS_EXT_SRP_MISSING_CLIENT_USERNAME_CB:
-		ctx->srp_ctx.srp_Mask|=SSL_kSRP;
-		ctx->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback=(char *(*)(SSL *,void *))fp;
-		break;
 #endif
 #endif
 	case SSL_CTRL_SET_NOT_RESUMABLE_SESS_CB:

ssl/ssl.h

@@ -695,8 +695,6 @@ typedef struct srp_ctx_st
 	int (*SRP_verify_param_callback)(SSL *, void *);
 	/* set SRP client passwd callback */
 	char *(*SRP_give_srp_client_pwd_callback)(SSL *, void *);
-	/* set SRP client username callback */
-	char *(*SRP_TLS_ext_missing_srp_client_username_callback)(SSL *, void *);
 
 	char *login;
 	BIGNUM *N,*g,*s,*B,*A;
@@ -1581,11 +1579,11 @@ DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
 #define SSL_CTRL_SET_TLS_EXT_SRP_USERNAME_CB	75
 #define SSL_CTRL_SET_SRP_VERIFY_PARAM_CB		76
 #define SSL_CTRL_SET_SRP_GIVE_CLIENT_PWD_CB		77
-#define SSL_CTRL_SET_TLS_EXT_SRP_MISSING_CLIENT_USERNAME_CB		78
-#define SSL_CTRL_SET_SRP_ARG		79
-#define SSL_CTRL_SET_TLS_EXT_SRP_USERNAME		80
-#define SSL_CTRL_SET_TLS_EXT_SRP_STRENGTH		81
-#define SSL_CTRL_SET_TLS_EXT_SRP_PASSWORD		82
+
+#define SSL_CTRL_SET_SRP_ARG		78
+#define SSL_CTRL_SET_TLS_EXT_SRP_USERNAME		79
+#define SSL_CTRL_SET_TLS_EXT_SRP_STRENGTH		80
+#define SSL_CTRL_SET_TLS_EXT_SRP_PASSWORD		81
 #endif
 
 #define DTLS_CTRL_GET_TIMEOUT		73

ssl/ssltest.c

@@ -266,12 +266,6 @@ static char * MS_CALLBACK ssl_give_srp_client_pwd_cb(SSL *s, void *arg)
 	return BUF_strdup((char *)srp_client_arg->srppassin);
 	}
 
-static char * MS_CALLBACK missing_srp_username_callback(SSL *s, void *arg)
-	{
-	SRP_CLIENT_ARG *srp_client_arg = (SRP_CLIENT_ARG *)arg;
-	return BUF_strdup(srp_client_arg->srplogin);
-	}
-
 /* SRP server */
 /* This is a context that we pass to SRP server callbacks */
 typedef struct srp_server_arg_st
@@ -617,7 +611,6 @@ int main(int argc, char *argv[])
 #endif
 #ifndef OPENSSL_NO_SRP
 	/* client */
-	int srp_lateuser = 0;
 	SRP_CLIENT_ARG srp_client_arg = {NULL,NULL};
 	/* server */
 	SRP_SERVER_ARG srp_server_arg = {NULL,NULL};
@@ -1147,9 +1140,7 @@ bad:
 #ifndef OPENSSL_NO_SRP
         if (srp_client_arg.srplogin)
 		{
-		if (srp_lateuser) 
-			SSL_CTX_set_srp_missing_srp_username_callback(c_ctx,missing_srp_username_callback);
-		else if (!SSL_CTX_set_srp_username(c_ctx, srp_client_arg.srplogin))
+		if (!SSL_CTX_set_srp_username(c_ctx, srp_client_arg.srplogin))
 			{
 			BIO_printf(bio_err,"Unable to set SRP username\n");
 			goto end;

ssl/tls_srp.c

@@ -4,7 +4,7 @@
  * for the EdelKey project and contributed to the OpenSSL project 2004.
  */
 /* ====================================================================
- * Copyright (c) 2004 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 2004-2011 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -82,7 +82,6 @@ int SSL_CTX_SRP_CTX_free(struct ssl_ctx_st *ctx)
 	ctx->srp_ctx.SRP_cb_arg = NULL;
 	ctx->srp_ctx.SRP_verify_param_callback = NULL;
 	ctx->srp_ctx.SRP_give_srp_client_pwd_callback = NULL;
-	ctx->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback = NULL;
 	ctx->srp_ctx.N = NULL;
 	ctx->srp_ctx.g = NULL;
 	ctx->srp_ctx.s = NULL;
@@ -115,7 +114,6 @@ int SSL_SRP_CTX_free(struct ssl_st *s)
 	s->srp_ctx.SRP_cb_arg = NULL;
 	s->srp_ctx.SRP_verify_param_callback = NULL;
 	s->srp_ctx.SRP_give_srp_client_pwd_callback = NULL;
-	s->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback = NULL;
 	s->srp_ctx.N = NULL;
 	s->srp_ctx.g = NULL;
 	s->srp_ctx.s = NULL;
@@ -144,7 +142,6 @@ int SSL_SRP_CTX_init(struct ssl_st *s)
 	s->srp_ctx.SRP_verify_param_callback = ctx->srp_ctx.SRP_verify_param_callback;
 	/* set SRP client passwd callback */
 	s->srp_ctx.SRP_give_srp_client_pwd_callback = ctx->srp_ctx.SRP_give_srp_client_pwd_callback;
-	s->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback = ctx->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback;
 
 	s->srp_ctx.N = NULL;
 	s->srp_ctx.g = NULL;
@@ -212,7 +209,6 @@ int SSL_CTX_SRP_CTX_init(struct ssl_ctx_st *ctx)
 	ctx->srp_ctx.SRP_verify_param_callback = NULL;
 	/* set SRP client passwd callback */
 	ctx->srp_ctx.SRP_give_srp_client_pwd_callback = NULL;
-	ctx->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback = NULL;
 
 	ctx->srp_ctx.N = NULL;
 	ctx->srp_ctx.g = NULL;
@@ -440,16 +436,6 @@ int SRP_Calc_A_param(SSL *s)
 	return 1;
 	}
 
-int SRP_have_to_put_srp_username(SSL *s)
-	{
-	if (s->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback == NULL)
-		return 0;
-	if ((s->srp_ctx.login = s->srp_ctx.SRP_TLS_ext_missing_srp_client_username_callback(s,s->srp_ctx.SRP_cb_arg)) == NULL)
-		return 0;
-	s->srp_ctx.srp_Mask|=SSL_kSRP;
-	return 1;
-	}
-
 BIGNUM *SSL_get_srp_g(SSL *s)
 	{
 	if (s->srp_ctx.g != NULL)
@@ -521,11 +507,4 @@ int SSL_CTX_set_srp_client_pwd_callback(SSL_CTX *ctx, char *(*cb)(SSL *,void *))
 				      (void (*)(void))cb);
 	}
 
-int SSL_CTX_set_srp_missing_srp_username_callback(SSL_CTX *ctx,
-						  char *(*cb)(SSL *,void *))
-	{
-	return tls1_ctx_callback_ctrl(ctx,
-			    SSL_CTRL_SET_TLS_EXT_SRP_MISSING_CLIENT_USERNAME_CB,
-				      (void (*)(void))cb);
-	}
 #endif