doc/man3/SSL_CTX_set_srp_password.pod - third_party/openssl - Git at Google

 =pod

 =head1 NAME

 SSL_CTX_set_srp_username,
 SSL_CTX_set_srp_password,
 SSL_CTX_set_srp_strength,
 SSL_CTX_set_srp_cb_arg,
 SSL_CTX_set_srp_username_callback,
 SSL_CTX_set_srp_client_pwd_callback,
 SSL_CTX_set_srp_verify_param_callback,
 SSL_set_srp_server_param,
 SSL_set_srp_server_param_pw,
 SSL_get_srp_g,
 SSL_get_srp_N,
 SSL_get_srp_username,
 SSL_get_srp_userinfo
 - SRP control operations

 =head1 SYNOPSIS

  #include <openssl/ssl.h>

 The following functions have been deprecated since OpenSSL 3.0, and can be
 hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
 see L<openssl_user_macros(7)>:

  int SSL_CTX_set_srp_username(SSL_CTX *ctx, char *name);
  int SSL_CTX_set_srp_password(SSL_CTX *ctx, char *password);
  int SSL_CTX_set_srp_strength(SSL_CTX *ctx, int strength);
  int SSL_CTX_set_srp_cb_arg(SSL_CTX *ctx, void *arg);
  int SSL_CTX_set_srp_username_callback(SSL_CTX *ctx,
                                        int (*cb) (SSL *s, int *ad, void *arg));
  int SSL_CTX_set_srp_client_pwd_callback(SSL_CTX *ctx,
                                          char *(*cb) (SSL *s, void *arg));
  int SSL_CTX_set_srp_verify_param_callback(SSL_CTX *ctx,
                                            int (*cb) (SSL *s, void *arg));

  int SSL_set_srp_server_param(SSL *s, const BIGNUM *N, const BIGNUM *g,
                               BIGNUM *sa, BIGNUM *v, char *info);
  int SSL_set_srp_server_param_pw(SSL *s, const char *user, const char *pass,
                                  const char *grp);

  BIGNUM *SSL_get_srp_g(SSL *s);
  BIGNUM *SSL_get_srp_N(SSL *s);

  char *SSL_get_srp_username(SSL *s);
  char *SSL_get_srp_userinfo(SSL *s);

 =head1 DESCRIPTION

 All of the functions described on this page are deprecated. There are no
 available replacement functions at this time.

 These functions provide access to SRP (Secure Remote Password) parameters,
 an alternate authentication mechanism for TLS. SRP allows the use of usernames
 and passwords over unencrypted channels without revealing the password to an
 eavesdropper. SRP also supplies a shared secret at the end of the authentication
 sequence that can be used to generate encryption keys.

 The SRP protocol, version 3 is specified in RFC 2945. SRP version 6 is described
 in RFC 5054 with applications to TLS authentication.

 The SSL_CTX_set_srp_username() function sets the SRP username for B<ctx>. This
 should be called on the client prior to creating a connection to the server.
 The length of B<name> must be shorter or equal to 255 characters.

 The SSL_CTX_set_srp_password() function sets the SRP password for B<ctx>. This
 may be called on the client prior to creating a connection to the server.
 This overrides the effect of SSL_CTX_set_srp_client_pwd_callback().

 The SSL_CTX_set_srp_strength() function sets the SRP strength for B<ctx>. This
 is the minimal length of the SRP prime in bits. If not specified 1024 is used.
 If not satisfied by the server key exchange the connection will be rejected.

 The SSL_CTX_set_srp_cb_arg() function sets an extra parameter that will
 be passed to all following callbacks as B<arg>.

 The SSL_CTX_set_srp_username_callback() function sets the server side callback
 that is invoked when an SRP username is found in a ClientHello.
 The callback parameters are the SSL connection B<s>, a writable error flag B<ad>
 and the extra argument B<arg> set by SSL_CTX_set_srp_cb_arg().
 This callback should setup the server for the key exchange by calling
 SSL_set_srp_server_param() with the appropriate parameters for the received
 username. The username can be obtained by calling SSL_get_srp_username().
 See L<SRP_VBASE_init(3)> to parse the verifier file created by L<openssl-srp(1)> or
 L<SRP_create_verifier(3)> to generate it.
 The callback should return B<SSL_ERROR_NONE> to proceed with the server key exchange,
 B<SSL3_AL_FATAL> for a fatal error or any value < 0 for a retryable error.
 In the event of a B<SSL3_AL_FATAL> the alert flag given by B<*al> will be sent
 back. By default this will be B<SSL_AD_UNKNOWN_PSK_IDENTITY>.

 The SSL_CTX_set_srp_client_pwd_callback() function sets the client password
 callback on the client.
 The callback parameters are the SSL connection B<s> and the extra argument B<arg>
 set by SSL_CTX_set_srp_cb_arg().
 The callback will be called as part of the generation of the client secrets.
 It should return the client password in text form or NULL to abort the connection.
 The resulting memory will be freed by the library as part of the callback resolution.
 This overrides the effect of SSL_CTX_set_srp_password().

 The SSL_CTX_set_srp_verify_param_callback() sets the SRP gN parameter verification
 callback on the client. This allows the client to perform custom verification when
 receiving the server SRP proposed parameters.
 The callback parameters are the SSL connection B<s> and the extra argument B<arg>
 set by SSL_CTX_set_srp_cb_arg().
 The callback should return a positive value to accept the server parameters.
 Returning 0 or a negative value will abort the connection. The server parameters
 can be obtained by calling SSL_get_srp_N() and SSL_get_srp_g().
 Sanity checks are already performed by the library after the handshake
 (B % N non zero, check against the strength parameter) and are not necessary.
 If no callback is set the g and N parameters will be checked against
 known RFC 5054 values.

 The SSL_set_srp_server_param() function sets all SRP parameters for
 the connection B<s>. B<N> and B<g> are the SRP group parameters, B<sa> is the
 user salt, B<v> the password verifier and B<info> is the optional user info.

 The SSL_set_srp_server_param_pw() function sets all SRP parameters for the
 connection B<s> by generating a random salt and a password verifier.
 B<user> is the username, B<pass> the password and B<grp> the SRP group parameters
 identifier for L<SRP_get_default_gN(3)>.

 The SSL_get_srp_g() function returns the SRP group generator for B<s>, or from
 the underlying SSL_CTX if it is NULL.

 The SSL_get_srp_N() function returns the SRP prime for B<s>, or from
 the underlying SSL_CTX if it is NULL.

 The SSL_get_srp_username() function returns the SRP username for B<s>, or from
 the underlying SSL_CTX if it is NULL.

 The SSL_get_srp_userinfo() function returns the SRP user info for B<s>, or from
 the underlying SSL_CTX if it is NULL.

 =head1 RETURN VALUES

 All SSL_CTX_set_* functions return 1 on success and 0 on failure.

 SSL_set_srp_server_param() returns 1 on success and -1 on failure.

 The SSL_get_SRP_* functions return a pointer to the requested data, the memory
 is owned by the library and should not be freed by the caller.

 =head1 EXAMPLES

 Setup SRP parameters on the client:

  #include <openssl/ssl.h>

  const char *username = "username";
  const char *password = "password";

  SSL_CTX *ctx = SSL_CTX_new(TLS_client_method());
  if (!ctx)
      /* Error */
  if (!SSL_CTX_set_srp_username(ctx, username))
      /* Error */
  if (!SSL_CTX_set_srp_password(ctx, password))
      /* Error */

 Setup SRP server with verifier file:

  #include <openssl/srp.h>
  #include <openssl/ssl.h>

  const char *srpvfile = "password.srpv";

  int srpServerCallback(SSL *s, int *ad, void *arg)
  {
      SRP_VBASE *srpData = (SRP_VBASE*) arg;
      char *username = SSL_get_srp_username(s);

      SRP_user_pwd *user_pwd = SRP_VBASE_get1_by_user(srpData, username);
      if (!user_pwd)
          /* Error */
          return SSL3_AL_FATAL;

      if (SSL_set_srp_server_param(s, user_pwd->N, user_pwd->g,
          user_pwd->s, user_pwd->v, user_pwd->info) < 0)
          /* Error */

      SRP_user_pwd_free(user_pwd);
      return SSL_ERROR_NONE;
  }

  SSL_CTX *ctx = SSL_CTX_new(TLS_server_method());
  if (!ctx)
      /* Error */

  /*
   * seedKey should contain a NUL terminated sequence
   * of random non NUL bytes
   */
  const char *seedKey;

  SRP_VBASE *srpData = SRP_VBASE_new(seedKey);
  if (SRP_VBASE_init(srpData, (char*) srpvfile) != SRP_NO_ERROR)
     /* Error */

  SSL_CTX_set_srp_cb_arg(ctx, srpData);
  SSL_CTX_set_srp_username_callback(ctx, srpServerCallback);

 =head1 SEE ALSO

 L<ssl(7)>,
 L<openssl-srp(1)>,
 L<SRP_VBASE_new(3)>,
 L<SRP_create_verifier(3)>

 =head1 HISTORY

 These functions were added in OpenSSL 1.0.1 and deprecated in OpenSSL 3.0.

 =head1 COPYRIGHT

 Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.

 Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy
 in the file LICENSE in the source distribution or at
 L<https://www.openssl.org/source/license.html>.

 =cut
	=pod

	=head1 NAME

	SSL_CTX_set_srp_username,
	SSL_CTX_set_srp_password,
	SSL_CTX_set_srp_strength,
	SSL_CTX_set_srp_cb_arg,
	SSL_CTX_set_srp_username_callback,
	SSL_CTX_set_srp_client_pwd_callback,
	SSL_CTX_set_srp_verify_param_callback,
	SSL_set_srp_server_param,
	SSL_set_srp_server_param_pw,
	SSL_get_srp_g,
	SSL_get_srp_N,
	SSL_get_srp_username,
	SSL_get_srp_userinfo
	- SRP control operations

	=head1 SYNOPSIS

	#include <openssl/ssl.h>

	The following functions have been deprecated since OpenSSL 3.0, and can be
	hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
	see L<openssl_user_macros(7)>:

	int SSL_CTX_set_srp_username(SSL_CTX ctx, char name);
	int SSL_CTX_set_srp_password(SSL_CTX ctx, char password);
	int SSL_CTX_set_srp_strength(SSL_CTX *ctx, int strength);
	int SSL_CTX_set_srp_cb_arg(SSL_CTX ctx, void arg);
	int SSL_CTX_set_srp_username_callback(SSL_CTX *ctx,
	int (cb) (SSL s, int ad, void arg));
	int SSL_CTX_set_srp_client_pwd_callback(SSL_CTX *ctx,
	char (cb) (SSL s, void arg));
	int SSL_CTX_set_srp_verify_param_callback(SSL_CTX *ctx,
	int (cb) (SSL s, void *arg));

	int SSL_set_srp_server_param(SSL s, const BIGNUM N, const BIGNUM *g,
	BIGNUM sa, BIGNUM v, char *info);
	int SSL_set_srp_server_param_pw(SSL s, const char user, const char *pass,
	const char *grp);

	BIGNUM SSL_get_srp_g(SSL s);
	BIGNUM SSL_get_srp_N(SSL s);

	char SSL_get_srp_username(SSL s);
	char SSL_get_srp_userinfo(SSL s);

	=head1 DESCRIPTION

	All of the functions described on this page are deprecated. There are no
	available replacement functions at this time.

	These functions provide access to SRP (Secure Remote Password) parameters,
	an alternate authentication mechanism for TLS. SRP allows the use of usernames
	and passwords over unencrypted channels without revealing the password to an
	eavesdropper. SRP also supplies a shared secret at the end of the authentication
	sequence that can be used to generate encryption keys.

	The SRP protocol, version 3 is specified in RFC 2945. SRP version 6 is described
	in RFC 5054 with applications to TLS authentication.

	The SSL_CTX_set_srp_username() function sets the SRP username for B<ctx>. This
	should be called on the client prior to creating a connection to the server.
	The length of B<name> must be shorter or equal to 255 characters.

	The SSL_CTX_set_srp_password() function sets the SRP password for B<ctx>. This
	may be called on the client prior to creating a connection to the server.
	This overrides the effect of SSL_CTX_set_srp_client_pwd_callback().

	The SSL_CTX_set_srp_strength() function sets the SRP strength for B<ctx>. This
	is the minimal length of the SRP prime in bits. If not specified 1024 is used.
	If not satisfied by the server key exchange the connection will be rejected.

	The SSL_CTX_set_srp_cb_arg() function sets an extra parameter that will
	be passed to all following callbacks as B<arg>.

	The SSL_CTX_set_srp_username_callback() function sets the server side callback
	that is invoked when an SRP username is found in a ClientHello.
	The callback parameters are the SSL connection B<s>, a writable error flag B<ad>
	and the extra argument B<arg> set by SSL_CTX_set_srp_cb_arg().
	This callback should setup the server for the key exchange by calling
	SSL_set_srp_server_param() with the appropriate parameters for the received
	username. The username can be obtained by calling SSL_get_srp_username().
	See L<SRP_VBASE_init(3)> to parse the verifier file created by L<openssl-srp(1)> or
	L<SRP_create_verifier(3)> to generate it.
	The callback should return B<SSL_ERROR_NONE> to proceed with the server key exchange,
	B<SSL3_AL_FATAL> for a fatal error or any value < 0 for a retryable error.
	In the event of a B<SSL3_AL_FATAL> the alert flag given by B<*al> will be sent
	back. By default this will be B<SSL_AD_UNKNOWN_PSK_IDENTITY>.

	The SSL_CTX_set_srp_client_pwd_callback() function sets the client password
	callback on the client.
	The callback parameters are the SSL connection B<s> and the extra argument B<arg>
	set by SSL_CTX_set_srp_cb_arg().
	The callback will be called as part of the generation of the client secrets.
	It should return the client password in text form or NULL to abort the connection.
	The resulting memory will be freed by the library as part of the callback resolution.
	This overrides the effect of SSL_CTX_set_srp_password().

	The SSL_CTX_set_srp_verify_param_callback() sets the SRP gN parameter verification
	callback on the client. This allows the client to perform custom verification when
	receiving the server SRP proposed parameters.
	The callback parameters are the SSL connection B<s> and the extra argument B<arg>
	set by SSL_CTX_set_srp_cb_arg().
	The callback should return a positive value to accept the server parameters.
	Returning 0 or a negative value will abort the connection. The server parameters
	can be obtained by calling SSL_get_srp_N() and SSL_get_srp_g().
	Sanity checks are already performed by the library after the handshake
	(B % N non zero, check against the strength parameter) and are not necessary.
	If no callback is set the g and N parameters will be checked against
	known RFC 5054 values.

	The SSL_set_srp_server_param() function sets all SRP parameters for
	the connection B<s>. B<N> and B<g> are the SRP group parameters, B<sa> is the
	user salt, B<v> the password verifier and B<info> is the optional user info.

	The SSL_set_srp_server_param_pw() function sets all SRP parameters for the
	connection B<s> by generating a random salt and a password verifier.
	B<user> is the username, B<pass> the password and B<grp> the SRP group parameters
	identifier for L<SRP_get_default_gN(3)>.

	The SSL_get_srp_g() function returns the SRP group generator for B<s>, or from
	the underlying SSL_CTX if it is NULL.

	The SSL_get_srp_N() function returns the SRP prime for B<s>, or from
	the underlying SSL_CTX if it is NULL.

	The SSL_get_srp_username() function returns the SRP username for B<s>, or from
	the underlying SSL_CTX if it is NULL.

	The SSL_get_srp_userinfo() function returns the SRP user info for B<s>, or from
	the underlying SSL_CTX if it is NULL.

	=head1 RETURN VALUES

	All SSL_CTX_set_* functions return 1 on success and 0 on failure.

	SSL_set_srp_server_param() returns 1 on success and -1 on failure.

	The SSL_get_SRP_* functions return a pointer to the requested data, the memory
	is owned by the library and should not be freed by the caller.

	=head1 EXAMPLES

	Setup SRP parameters on the client:

	#include <openssl/ssl.h>

	const char *username = "username";
	const char *password = "password";

	SSL_CTX *ctx = SSL_CTX_new(TLS_client_method());
	if (!ctx)
	/* Error */
	if (!SSL_CTX_set_srp_username(ctx, username))
	/* Error */
	if (!SSL_CTX_set_srp_password(ctx, password))
	/* Error */

	Setup SRP server with verifier file:

	#include <openssl/srp.h>
	#include <openssl/ssl.h>

	const char *srpvfile = "password.srpv";

	int srpServerCallback(SSL s, int ad, void *arg)
	{
	SRP_VBASE srpData = (SRP_VBASE) arg;
	char *username = SSL_get_srp_username(s);

	SRP_user_pwd *user_pwd = SRP_VBASE_get1_by_user(srpData, username);
	if (!user_pwd)
	/* Error */
	return SSL3_AL_FATAL;

	if (SSL_set_srp_server_param(s, user_pwd->N, user_pwd->g,
	user_pwd->s, user_pwd->v, user_pwd->info) < 0)
	/* Error */

	SRP_user_pwd_free(user_pwd);
	return SSL_ERROR_NONE;
	}

	SSL_CTX *ctx = SSL_CTX_new(TLS_server_method());
	if (!ctx)
	/* Error */

	/*
	* seedKey should contain a NUL terminated sequence
	* of random non NUL bytes
	*/
	const char *seedKey;

	SRP_VBASE *srpData = SRP_VBASE_new(seedKey);
	if (SRP_VBASE_init(srpData, (char*) srpvfile) != SRP_NO_ERROR)
	/* Error */

	SSL_CTX_set_srp_cb_arg(ctx, srpData);
	SSL_CTX_set_srp_username_callback(ctx, srpServerCallback);

	=head1 SEE ALSO

	L<ssl(7)>,
	L<openssl-srp(1)>,
	L<SRP_VBASE_new(3)>,
	L<SRP_create_verifier(3)>

	=head1 HISTORY

	These functions were added in OpenSSL 1.0.1 and deprecated in OpenSSL 3.0.

	=head1 COPYRIGHT

	Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.

	Licensed under the Apache License 2.0 (the "License"). You may not use
	this file except in compliance with the License. You can obtain a copy
	in the file LICENSE in the source distribution or at
	L<https://www.openssl.org/source/license.html>.

	=cut