Rename "scram" to "scram-sha-256" in pg_hba.conf and password_encryption.

Per discussion, plain "scram" is confusing because we actually implement
SCRAM-SHA-256 rather than the original SCRAM that uses SHA-1 as the hash
algorithm. If we add support for SCRAM-SHA-512 or some other mechanism in
the SCRAM family in the future, that would become even more confusing.

Most of the internal files and functions still use just "scram" as a
shorthand for SCRMA-SHA-256, but I did change PASSWORD_TYPE_SCRAM to
PASSWORD_TYPE_SCRAM_SHA_256, as that could potentially be used by 3rd
party extensions that hook into the password-check hook.

Michael Paquier did this in an earlier version of the SCRAM patch set
already, but I didn't include that in the version that was committed.

Discussion: https://www.postgresql.org/message-id/fde71ff1-5858-90c8-99a9-1c2427e7bafb@iki.fi

doc/src/sgml/client-auth.sgml

@@ -412,7 +412,7 @@ hostnossl  <replaceable>database</replaceable>  <replaceable>user</replaceable>
        </varlistentry>
 
        <varlistentry>
-        <term><literal>scram</></term>
+        <term><literal>scram-sha-256</></term>
         <listitem>
          <para>
           Perform SCRAM-SHA-256 authentication to verify the user's
@@ -683,7 +683,7 @@ host    postgres        all             192.168.93.0/24         ident
 # "postgres" if the user's password is correctly supplied.
 #
 # TYPE  DATABASE        USER            ADDRESS                 METHOD
-host    postgres        all             192.168.12.10/32        scram
+host    postgres        all             192.168.12.10/32        scram-sha-256
 
 # Allow any user from hosts in the example.com domain to connect to
 # any database if the user's password is correctly supplied.
@@ -694,7 +694,7 @@ host    postgres        all             192.168.12.10/32        scram
 #
 # TYPE  DATABASE        USER            ADDRESS                 METHOD
 host    all             mike            .example.com            md5
-host    all             all             .example.com            scram
+host    all             all             .example.com            scram-sha-256
 
 # In the absence of preceding "host" lines, these two lines will
 # reject all connections from 192.168.54.1 (since that entry will be
@@ -922,7 +922,7 @@ omicron         bryanh                  guest1
    </indexterm>
 
    <para>
-    The password-based authentication methods are <literal>scram</>,
+    The password-based authentication methods are <literal>scram-sha-256</>,
     <literal>md5</>, and <literal>password</>. These methods operate
     similarly except for the way that the password is sent across the
     connection.
@@ -939,8 +939,9 @@ omicron         bryanh                  guest1
 
 
    <para>
-    <literal>scram</> performs SCRAM-SHA-256 authentication, as described
-    in <ulink url="https://tools.ietf.org/html/rfc5802">RFC5802</ulink>. It
+    <literal>scram-sha-256</> performs SCRAM-SHA-256 authentication, as
+    described in
+    <ulink url="https://tools.ietf.org/html/rfc5802">RFC5802</ulink>. It
     is a challenge-response scheme, that prevents password sniffing on
     untrusted connections. It is more secure than the <literal>md5</>
     method, but might not be supported by older clients.
@@ -953,7 +954,7 @@ omicron         bryanh                  guest1
     protection if an attacker manages to steal the password hash from the
     server, and it cannot be used with the <xref
     linkend="guc-db-user-namespace"> feature. For all other users,
-    <literal>md5</> works the same as <literal>scram</>.
+    <literal>md5</> works the same as <literal>scram-sha-256</>.
    </para>
 
    <para>

doc/src/sgml/config.sgml

@@ -1194,8 +1194,8 @@ include_dir 'conf.d'
         stores the password as an MD5 hash. Setting this to <literal>plain</> stores
         it in plaintext. <literal>on</> and <literal>off</> are also accepted, as
         aliases for <literal>md5</> and <literal>plain</>, respectively.  Setting
-        this parameter to <literal>scram</> will encrypt the password with
-        SCRAM-SHA-256.
+        this parameter to <literal>scram-sha-256</> will encrypt the password
+        with SCRAM-SHA-256.
        </para>
       </listitem>
      </varlistentry>

src/backend/commands/user.c

@@ -140,8 +140,8 @@ CreateRole(ParseState *pstate, CreateRoleStmt *stmt)
 			dpassword = defel;
 			if (strcmp(defel->defname, "encryptedPassword") == 0)
 			{
-				if (Password_encryption == PASSWORD_TYPE_SCRAM)
-					password_type = PASSWORD_TYPE_SCRAM;
+				if (Password_encryption == PASSWORD_TYPE_SCRAM_SHA_256)
+					password_type = PASSWORD_TYPE_SCRAM_SHA_256;
 				else
 					password_type = PASSWORD_TYPE_MD5;
 			}
@@ -548,8 +548,8 @@ AlterRole(AlterRoleStmt *stmt)
 			dpassword = defel;
 			if (strcmp(defel->defname, "encryptedPassword") == 0)
 			{
-				if (Password_encryption == PASSWORD_TYPE_SCRAM)
-					password_type = PASSWORD_TYPE_SCRAM;
+				if (Password_encryption == PASSWORD_TYPE_SCRAM_SHA_256)
+					password_type = PASSWORD_TYPE_SCRAM_SHA_256;
 				else
 					password_type = PASSWORD_TYPE_MD5;
 			}

src/backend/libpq/auth-scram.c

@@ -183,7 +183,7 @@ pg_be_scram_init(const char *username, const char *shadow_pass)
 	{
 		int			password_type = get_password_type(shadow_pass);
 
-		if (password_type == PASSWORD_TYPE_SCRAM)
+		if (password_type == PASSWORD_TYPE_SCRAM_SHA_256)
 		{
 			if (parse_scram_verifier(shadow_pass, &state->salt, &state->iterations,
 									 state->StoredKey, state->ServerKey))

src/backend/libpq/auth.c

@@ -50,7 +50,7 @@ static char *recv_password_packet(Port *port);
 
 
 /*----------------------------------------------------------------
- * Password-based authentication methods (password, md5, and scram)
+ * Password-based authentication methods (password, md5, and scram-sha-256)
  *----------------------------------------------------------------
  */
 static int	CheckPasswordAuth(Port *port, char **logdetail);
@@ -757,10 +757,10 @@ CheckPWChallengeAuth(Port *port, char **logdetail)
 	 * If the user does not exist, or has no password, we still go through the
 	 * motions of authentication, to avoid revealing to the client that the
 	 * user didn't exist.  If 'md5' is allowed, we choose whether to use 'md5'
-	 * or 'scram' authentication based on current password_encryption setting.
-	 * The idea is that most genuine users probably have a password of that
-	 * type, if we pretend that this user had a password of that type, too, it
-	 * "blends in" best.
+	 * or 'scram-sha-256' authentication based on current password_encryption
+	 * setting.  The idea is that most genuine users probably have a password
+	 * of that type, if we pretend that this user had a password of that type,
+	 * too, it "blends in" best.
 	 *
 	 * If the user had a password, but it was expired, we'll use the details
 	 * of the expired password for the authentication, but report it as
@@ -773,9 +773,9 @@ CheckPWChallengeAuth(Port *port, char **logdetail)
 
 	/*
 	 * If 'md5' authentication is allowed, decide whether to perform 'md5' or
-	 * 'scram' authentication based on the type of password the user has.  If
-	 * it's an MD5 hash, we must do MD5 authentication, and if it's a SCRAM
-	 * verifier, we must do SCRAM authentication.  If it's stored in
+	 * 'scram-sha-256' authentication based on the type of password the user
+	 * has.  If it's an MD5 hash, we must do MD5 authentication, and if it's
+	 * a SCRAM verifier, we must do SCRAM authentication.  If it's stored in
 	 * plaintext, we could do either one, so we opt for the more secure
 	 * mechanism, SCRAM.
 	 *

src/backend/libpq/crypt.c

@@ -101,7 +101,7 @@ get_password_type(const char *shadow_pass)
 	if (strncmp(shadow_pass, "md5", 3) == 0 && strlen(shadow_pass) == MD5_PASSWD_LEN)
 		return PASSWORD_TYPE_MD5;
 	if (strncmp(shadow_pass, "scram-sha-256:", strlen("scram-sha-256:")) == 0)
-		return PASSWORD_TYPE_SCRAM;
+		return PASSWORD_TYPE_SCRAM_SHA_256;
 	return PASSWORD_TYPE_PLAINTEXT;
 }
 
@@ -141,7 +141,7 @@ encrypt_password(PasswordType target_type, const char *role,
 						elog(ERROR, "password encryption failed");
 					return encrypted_password;
 
-				case PASSWORD_TYPE_SCRAM:
+				case PASSWORD_TYPE_SCRAM_SHA_256:
 
 					/*
 					 * cannot convert a SCRAM verifier to an MD5 hash, so fall
@@ -152,7 +152,7 @@ encrypt_password(PasswordType target_type, const char *role,
 			}
 			break;
 
-		case PASSWORD_TYPE_SCRAM:
+		case PASSWORD_TYPE_SCRAM_SHA_256:
 			switch (guessed_type)
 			{
 				case PASSWORD_TYPE_PLAINTEXT:
@@ -164,7 +164,7 @@ encrypt_password(PasswordType target_type, const char *role,
 					 * cannot convert an MD5 hash to a SCRAM verifier, so fall
 					 * through to save the MD5 hash instead.
 					 */
-				case PASSWORD_TYPE_SCRAM:
+				case PASSWORD_TYPE_SCRAM_SHA_256:
 					return pstrdup(password);
 			}
 			break;
@@ -280,7 +280,7 @@ plain_crypt_verify(const char *role, const char *shadow_pass,
 	 */
 	switch (get_password_type(shadow_pass))
 	{
-		case PASSWORD_TYPE_SCRAM:
+		case PASSWORD_TYPE_SCRAM_SHA_256:
 			if (scram_verify_plain_password(role,
 											client_pass,
 											shadow_pass))

src/backend/libpq/hba.c

@@ -126,7 +126,7 @@ static const char *const UserAuthName[] =
 	"ident",
 	"password",
 	"md5",
-	"scram",
+	"scram-sha256",
 	"gss",
 	"sspi",
 	"pam",
@@ -1327,7 +1327,7 @@ parse_hba_line(TokenizedLine *tok_line, int elevel)
 		}
 		parsedline->auth_method = uaMD5;
 	}
-	else if (strcmp(token->string, "scram") == 0)
+	else if (strcmp(token->string, "scram-sha-256") == 0)
 		parsedline->auth_method = uaSCRAM;
 	else if (strcmp(token->string, "pam") == 0)
 #ifdef USE_PAM

src/backend/libpq/pg_hba.conf.sample

@@ -42,10 +42,10 @@
 # or "samenet" to match any address in any subnet that the server is
 # directly connected to.
 #
-# METHOD can be "trust", "reject", "md5", "password", "scram", "gss",
-# "sspi", "ident", "peer", "pam", "ldap", "radius" or "cert".  Note that
-# "password" sends passwords in clear text; "md5" or "scram" are preferred
-# since they send encrypted passwords.
+# METHOD can be "trust", "reject", "md5", "password", "scram-sha-256",
+# "gss", "sspi", "ident", "peer", "pam", "ldap", "radius" or "cert".
+# Note that "password" sends passwords in clear text; "md5" or
+# "scram-sha-256" are preferred since they send encrypted passwords.
 #
 # OPTIONS are a set of options for the authentication in the format
 # NAME=VALUE.  The available options depend on the different

src/backend/utils/misc/guc.c

@@ -410,7 +410,7 @@ static const struct config_enum_entry force_parallel_mode_options[] = {
 static const struct config_enum_entry password_encryption_options[] = {
 	{"plain", PASSWORD_TYPE_PLAINTEXT, false},
 	{"md5", PASSWORD_TYPE_MD5, false},
-	{"scram", PASSWORD_TYPE_SCRAM, false},
+	{"scram-sha-256", PASSWORD_TYPE_SCRAM_SHA_256, false},
 	{"off", PASSWORD_TYPE_PLAINTEXT, false},
 	{"on", PASSWORD_TYPE_MD5, false},
 	{"true", PASSWORD_TYPE_MD5, true},

src/bin/initdb/initdb.c

@@ -77,7 +77,7 @@
 extern const char *select_default_timezone(const char *share_path);
 
 static const char *const auth_methods_host[] = {
-	"trust", "reject", "md5", "password", "scram", "ident", "radius",
+	"trust", "reject", "scram-sha-256", "md5", "password", "ident", "radius",
 #ifdef ENABLE_GSS
 	"gss",
 #endif
@@ -99,7 +99,7 @@ static const char *const auth_methods_host[] = {
 	NULL
 };
 static const char *const auth_methods_local[] = {
-	"trust", "reject", "md5", "scram", "password", "peer", "radius",
+	"trust", "reject", "scram-sha-256", "md5", "password", "peer", "radius",
 #ifdef USE_PAM
 	"pam", "pam ",
 #endif
@@ -1130,12 +1130,12 @@ setup_config(void)
 							  "#update_process_title = off");
 #endif
 
-	if (strcmp(authmethodlocal, "scram") == 0 ||
-		strcmp(authmethodhost, "scram") == 0)
+	if (strcmp(authmethodlocal, "scram-sha-256") == 0 ||
+		strcmp(authmethodhost, "scram-sha-256") == 0)
 	{
 		conflines = replace_token(conflines,
 								  "#password_encryption = md5",
-								  "password_encryption = scram");
+								  "password_encryption = scram-sha-256");
 	}
 
 	snprintf(path, sizeof(path), "%s/postgresql.conf", pg_data);
@@ -2329,16 +2329,16 @@ check_need_password(const char *authmethodlocal, const char *authmethodhost)
 {
 	if ((strcmp(authmethodlocal, "md5") == 0 ||
 		 strcmp(authmethodlocal, "password") == 0 ||
-		 strcmp(authmethodlocal, "scram") == 0) &&
+		 strcmp(authmethodlocal, "scram-sha-256") == 0) &&
 		(strcmp(authmethodhost, "md5") == 0 ||
 		 strcmp(authmethodhost, "password") == 0 ||
-		 strcmp(authmethodhost, "scram") == 0) &&
+		 strcmp(authmethodhost, "scram-sha-256") == 0) &&
 		!(pwprompt || pwfilename))
 	{
 		fprintf(stderr, _("%s: must specify a password for the superuser to enable %s authentication\n"), progname,
 				(strcmp(authmethodlocal, "md5") == 0 ||
 				 strcmp(authmethodlocal, "password") == 0 ||
-				 strcmp(authmethodlocal, "scram") == 0)
+				 strcmp(authmethodlocal, "scram-sha-256") == 0)
 				? authmethodlocal
 				: authmethodhost);
 		exit(1);

src/include/libpq/crypt.h

@@ -25,7 +25,7 @@ typedef enum PasswordType
 {
 	PASSWORD_TYPE_PLAINTEXT = 0,
 	PASSWORD_TYPE_MD5,
-	PASSWORD_TYPE_SCRAM
+	PASSWORD_TYPE_SCRAM_SHA_256
 } PasswordType;
 
 extern PasswordType get_password_type(const char *shadow_pass);

src/test/authentication/t/001_password.pl

@@ -51,7 +51,7 @@ SKIP:
 
 	# Create 3 roles with different password methods for each one. The same
 	# password is used for all of them.
-	$node->safe_psql('postgres', "SET password_encryption='scram'; CREATE ROLE scram_role LOGIN PASSWORD 'pass';");
+	$node->safe_psql('postgres', "SET password_encryption='scram-sha-256'; CREATE ROLE scram_role LOGIN PASSWORD 'pass';");
 	$node->safe_psql('postgres', "SET password_encryption='md5'; CREATE ROLE md5_role LOGIN PASSWORD 'pass';");
 	$node->safe_psql('postgres', "SET password_encryption='plain'; CREATE ROLE plain_role LOGIN PASSWORD 'pass';");
 	$ENV{"PGPASSWORD"} = 'pass';
@@ -68,12 +68,12 @@ SKIP:
 	test_role($node, 'md5_role', 'password', 0);
 	test_role($node, 'plain_role', 'password', 0);
 
-	# For "scram" method, user "plain_role" and "scram_role" should be able to
-	# connect.
-	reset_pg_hba($node, 'scram');
-	test_role($node, 'scram_role', 'scram', 0);
-	test_role($node, 'md5_role', 'scram', 2);
-	test_role($node, 'plain_role', 'scram', 0);
+	# For "scram-sha-256" method, user "plain_role" and "scram_role" should
+	# be able to connect.
+	reset_pg_hba($node, 'scram-sha-256');
+	test_role($node, 'scram_role', 'scram-sha-256', 0);
+	test_role($node, 'md5_role', 'scram-sha-256', 2);
+	test_role($node, 'plain_role', 'scram-sha-256', 0);
 
 	# For "md5" method, all users should be able to connect (SCRAM
 	# authentication will be performed for the user with a scram verifier.)

src/test/authentication/t/002_saslprep.pl

@@ -63,7 +63,7 @@ SKIP:
 
 	# Create test roles.
 	$node->safe_psql('postgres',
-"SET password_encryption='scram';
+"SET password_encryption='scram-sha-256';
  SET client_encoding='utf8';
  CREATE ROLE saslpreptest1_role LOGIN PASSWORD 'IX';
  CREATE ROLE saslpreptest4a_role LOGIN PASSWORD 'a';
@@ -73,7 +73,7 @@ SKIP:
 ");
 
 	# Require password from now on.
-	reset_pg_hba($node, 'scram');
+	reset_pg_hba($node, 'scram-sha-256');
 
 	# Check that #1 and #5 are treated the same as just 'IX'
 	test_login($node, 'saslpreptest1_role', "I\xc2\xadX", 0);

src/test/regress/expected/password.out

@@ -4,11 +4,11 @@
 -- Tests for GUC password_encryption
 SET password_encryption = 'novalue'; -- error
 ERROR:  invalid value for parameter "password_encryption": "novalue"
-HINT:  Available values: plain, md5, scram, off, on.
+HINT:  Available values: plain, md5, scram-sha-256, off, on.
 SET password_encryption = true; -- ok
 SET password_encryption = 'md5'; -- ok
 SET password_encryption = 'plain'; -- ok
-SET password_encryption = 'scram'; -- ok
+SET password_encryption = 'scram-sha-256'; -- ok
 -- consistency of password entries
 SET password_encryption = 'plain';
 CREATE ROLE regress_passwd1 PASSWORD 'role_pwd1';
@@ -16,7 +16,7 @@ SET password_encryption = 'md5';
 CREATE ROLE regress_passwd2 PASSWORD 'role_pwd2';
 SET password_encryption = 'on';
 CREATE ROLE regress_passwd3 PASSWORD 'role_pwd3';
-SET password_encryption = 'scram';
+SET password_encryption = 'scram-sha-256';
 CREATE ROLE regress_passwd4 PASSWORD 'role_pwd4';
 SET password_encryption = 'plain';
 CREATE ROLE regress_passwd5 PASSWORD NULL;
@@ -60,7 +60,7 @@ ALTER ROLE regress_passwd2 UNENCRYPTED PASSWORD 'md5dfa155cadd5f4ad57860162f3fab
 SET password_encryption = 'md5';
 ALTER ROLE regress_passwd3 ENCRYPTED PASSWORD 'foo'; -- encrypted with MD5
 ALTER ROLE regress_passwd4 ENCRYPTED PASSWORD 'scram-sha-256:VLK4RMaQLCvNtQ==:4096:3ded2376f7aafa93b1bdbd71bcc18b7d6ee50ed018029cc583d152ef3fc7d430:a6dd36dfc94c181956a6ae95f05e01b1864f0a22a2657d1de4ba84d2a24dc438'; -- client-supplied SCRAM verifier, use as it is
-SET password_encryption = 'scram';
+SET password_encryption = 'scram-sha-256';
 ALTER ROLE  regress_passwd5 ENCRYPTED PASSWORD 'foo'; -- create SCRAM verifier
 CREATE ROLE regress_passwd6 ENCRYPTED PASSWORD 'md53725413363ab045e20521bf36b8d8d7f'; -- encrypted with MD5, use as it is
 SELECT rolname, regexp_replace(rolpassword, '(scram-sha-256):([a-zA-Z0-9+/]+==):(\d+):(\w+):(\w+)', '\1:<salt>:\3:<storedkey>:<serverkey>') as rolpassword_masked

src/test/regress/sql/password.sql

@@ -7,7 +7,7 @@ SET password_encryption = 'novalue'; -- error
 SET password_encryption = true; -- ok
 SET password_encryption = 'md5'; -- ok
 SET password_encryption = 'plain'; -- ok
-SET password_encryption = 'scram'; -- ok
+SET password_encryption = 'scram-sha-256'; -- ok
 
 -- consistency of password entries
 SET password_encryption = 'plain';
@@ -16,7 +16,7 @@ SET password_encryption = 'md5';
 CREATE ROLE regress_passwd2 PASSWORD 'role_pwd2';
 SET password_encryption = 'on';
 CREATE ROLE regress_passwd3 PASSWORD 'role_pwd3';
-SET password_encryption = 'scram';
+SET password_encryption = 'scram-sha-256';
 CREATE ROLE regress_passwd4 PASSWORD 'role_pwd4';
 SET password_encryption = 'plain';
 CREATE ROLE regress_passwd5 PASSWORD NULL;
@@ -50,7 +50,7 @@ ALTER ROLE regress_passwd3 ENCRYPTED PASSWORD 'foo'; -- encrypted with MD5
 
 ALTER ROLE regress_passwd4 ENCRYPTED PASSWORD 'scram-sha-256:VLK4RMaQLCvNtQ==:4096:3ded2376f7aafa93b1bdbd71bcc18b7d6ee50ed018029cc583d152ef3fc7d430:a6dd36dfc94c181956a6ae95f05e01b1864f0a22a2657d1de4ba84d2a24dc438'; -- client-supplied SCRAM verifier, use as it is
 
-SET password_encryption = 'scram';
+SET password_encryption = 'scram-sha-256';
 ALTER ROLE  regress_passwd5 ENCRYPTED PASSWORD 'foo'; -- create SCRAM verifier
 CREATE ROLE regress_passwd6 ENCRYPTED PASSWORD 'md53725413363ab045e20521bf36b8d8d7f'; -- encrypted with MD5, use as it is