Tweak some SCRAM error messages and code comments

Clarify/correct some error messages, fix up some code comments that
confused SASL and SCRAM, and other minor fixes.  No changes in
functionality.

doc/src/sgml/protocol.sgml

@@ -1405,13 +1405,13 @@ ErrorMessage.
   </para>
 
   <para>
-When SCRAM-SHA-256 is used in PostgreSQL, the server will ignore the username
-that the client sends in the <structname>client-first-message</>. The username
+When SCRAM-SHA-256 is used in PostgreSQL, the server will ignore the user name
+that the client sends in the <structname>client-first-message</>. The user name
 that was already sent in the startup message is used instead.
 <productname>PostgreSQL</> supports multiple character encodings, while SCRAM
-dictates UTF-8 to be used for the username, so it might be impossible to
-represent the PostgreSQL username in UTF-8. To avoid confusion, the client
-should use <literal>pg_same_as_startup_message</literal> as the username in the
+dictates UTF-8 to be used for the user name, so it might be impossible to
+represent the PostgreSQL user name in UTF-8. To avoid confusion, the client
+should use <literal>pg_same_as_startup_message</literal> as the user name in the
 <structname>client-first-message</>.
   </para>
 
@@ -5274,7 +5274,7 @@ RowDescription (B)
 
 <varlistentry>
 <term>
-SASLInitialresponse (F)
+SASLInitialResponse (F)
 </term>
 <listitem>
 <para>

src/backend/libpq/auth-scram.c

@@ -573,7 +573,7 @@ mock_scram_verifier(const char *username, int *iterations, char **salt,
 }
 
 /*
- * Read the value in a given SASL exchange message for given attribute.
+ * Read the value in a given SCRAM exchange message for given attribute.
  */
 static char *
 read_attr_value(char **input, char attr)
@@ -585,7 +585,7 @@ read_attr_value(char **input, char attr)
 		ereport(ERROR,
 				(errcode(ERRCODE_PROTOCOL_VIOLATION),
 				 errmsg("malformed SCRAM message"),
-				 errdetail("Expected attribute '%c' but found %s.",
+				 errdetail("Expected attribute \"%c\" but found \"%s\".",
 						   attr, sanitize_char(*begin))));
 	begin++;
 
@@ -593,7 +593,7 @@ read_attr_value(char **input, char attr)
 		ereport(ERROR,
 				(errcode(ERRCODE_PROTOCOL_VIOLATION),
 				 errmsg("malformed SCRAM message"),
-				 errdetail("Expected character = for attribute %c.", attr)));
+				 errdetail("Expected character \"=\" for attribute \"%c\".", attr)));
 	begin++;
 
 	end = begin;
@@ -652,7 +652,7 @@ sanitize_char(char c)
 }
 
 /*
- * Read the next attribute and value in a SASL exchange message.
+ * Read the next attribute and value in a SCRAM exchange message.
  *
  * Returns NULL if there is attribute.
  */
@@ -674,7 +674,7 @@ read_any_attr(char **input, char *attr_p)
 		ereport(ERROR,
 				(errcode(ERRCODE_PROTOCOL_VIOLATION),
 				 errmsg("malformed SCRAM message"),
-				 errdetail("Attribute expected, but found invalid character %s.",
+				 errdetail("Attribute expected, but found invalid character \"%s\".",
 						   sanitize_char(attr))));
 	if (attr_p)
 		*attr_p = attr;
@@ -684,7 +684,7 @@ read_any_attr(char **input, char *attr_p)
 		ereport(ERROR,
 				(errcode(ERRCODE_PROTOCOL_VIOLATION),
 				 errmsg("malformed SCRAM message"),
-				 errdetail("Expected character = for attribute %c.", attr)));
+				 errdetail("Expected character \"=\" for attribute \"%c\".", attr)));
 	begin++;
 
 	end = begin;
@@ -703,7 +703,7 @@ read_any_attr(char **input, char *attr_p)
 }
 
 /*
- * Read and parse the first message from client in the context of a SASL
+ * Read and parse the first message from client in the context of a SCRAM
  * authentication exchange message.
  *
  * At this stage, any errors will be reported directly with ereport(ERROR).
@@ -802,14 +802,14 @@ read_client_first_message(scram_state *state, char *input)
 			ereport(ERROR,
 					(errcode(ERRCODE_PROTOCOL_VIOLATION),
 					 errmsg("malformed SCRAM message"),
-					 errdetail("Unexpected channel-binding flag %s.",
+					 errdetail("Unexpected channel-binding flag \"%s\".",
 							   sanitize_char(*input))));
 	}
 	if (*input != ',')
 		ereport(ERROR,
 				(errcode(ERRCODE_PROTOCOL_VIOLATION),
 				 errmsg("malformed SCRAM message"),
-				 errdetail("Comma expected, but found character %s.",
+				 errdetail("Comma expected, but found character \"%s\".",
 						   sanitize_char(*input))));
 	input++;
 
@@ -824,7 +824,7 @@ read_client_first_message(scram_state *state, char *input)
 		ereport(ERROR,
 				(errcode(ERRCODE_PROTOCOL_VIOLATION),
 				 errmsg("malformed SCRAM message"),
-				 errdetail("Unexpected attribute %s in client-first-message.",
+				 errdetail("Unexpected attribute \"%s\" in client-first-message.",
 						   sanitize_char(*input))));
 	input++;
 
@@ -929,7 +929,7 @@ verify_client_proof(scram_state *state)
 }
 
 /*
- * Build the first server-side message sent to the client in a SASL
+ * Build the first server-side message sent to the client in a SCRAM
  * communication exchange.
  */
 static char *

src/interfaces/libpq/fe-auth-scram.c

@@ -228,7 +228,7 @@ pg_fe_scram_exchange(void *opaq, char *input, int inputlen,
 			{
 				*success = false;
 				printfPQExpBuffer(errorMessage,
-								  libpq_gettext("invalid server signature\n"));
+								  libpq_gettext("incorrect server signature\n"));
 			}
 			*done = true;
 			state->state = FE_SCRAM_FINISHED;
@@ -249,7 +249,7 @@ error:
 }
 
 /*
- * Read value for an attribute part of a SASL message.
+ * Read value for an attribute part of a SCRAM message.
  */
 static char *
 read_attr_value(char **input, char attr, PQExpBuffer errorMessage)
@@ -260,7 +260,7 @@ read_attr_value(char **input, char attr, PQExpBuffer errorMessage)
 	if (*begin != attr)
 	{
 		printfPQExpBuffer(errorMessage,
-						  libpq_gettext("malformed SCRAM message (%c expected)\n"),
+						  libpq_gettext("malformed SCRAM message (attribute \"%c\" expected)\n"),
 						  attr);
 		return NULL;
 	}
@@ -269,7 +269,7 @@ read_attr_value(char **input, char attr, PQExpBuffer errorMessage)
 	if (*begin != '=')
 	{
 		printfPQExpBuffer(errorMessage,
-						  libpq_gettext("malformed SCRAM message (expected = in attr '%c')\n"),
+						  libpq_gettext("malformed SCRAM message (expected character \"=\" for attribute \"%c\")\n"),
 						  attr);
 		return NULL;
 	}
@@ -508,7 +508,7 @@ read_server_final_message(fe_scram_state *state, char *input,
 		char	   *errmsg = read_attr_value(&input, 'e', errormessage);
 
 		printfPQExpBuffer(errormessage,
-						  libpq_gettext("error received from server in SASL exchange: %s\n"),
+						  libpq_gettext("error received from server in SCRAM exchange: %s\n"),
 						  errmsg);
 		return false;
 	}