src/mail/ngx_mail_parse.c - nginx - Git at Google


 /*
  * Copyright (C) Igor Sysoev
  */


 #include <ngx_config.h>
 #include <ngx_core.h>
 #include <ngx_event.h>
 #include <ngx_mail.h>


 ngx_int_t
 ngx_mail_pop3_parse_command(ngx_mail_session_t *s)
 {
     u_char      ch, *p, *c, c0, c1, c2, c3;
     ngx_str_t  *arg;
     enum {
         sw_start = 0,
         sw_spaces_before_argument,
         sw_argument,
         sw_almost_done
     } state;

     state = s->state;

     for (p = s->buffer->pos; p < s->buffer->last; p++) {
         ch = *p;

         switch (state) {

         /* POP3 command */
         case sw_start:
             if (ch == ' ' || ch == CR || ch == LF) {
                 c = s->buffer->start;

                 if (p - c == 4) {

                     c0 = ngx_toupper(c[0]);
                     c1 = ngx_toupper(c[1]);
                     c2 = ngx_toupper(c[2]);
                     c3 = ngx_toupper(c[3]);

                     if (c0 == 'U' && c1 == 'S' && c2 == 'E' && c3 == 'R')
                     {
                         s->command = NGX_POP3_USER;

                     } else if (c0 == 'P' && c1 == 'A' && c2 == 'S' && c3 == 'S')
                     {
                         s->command = NGX_POP3_PASS;

                     } else if (c0 == 'A' && c1 == 'P' && c2 == 'O' && c3 == 'P')
                     {
                         s->command = NGX_POP3_APOP;

                     } else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
                     {
                         s->command = NGX_POP3_QUIT;

                     } else if (c0 == 'C' && c1 == 'A' && c2 == 'P' && c3 == 'A')
                     {
                         s->command = NGX_POP3_CAPA;

                     } else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
                     {
                         s->command = NGX_POP3_AUTH;

                     } else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
                     {
                         s->command = NGX_POP3_NOOP;
 #if (NGX_MAIL_SSL)
                     } else if (c0 == 'S' && c1 == 'T' && c2 == 'L' && c3 == 'S')
                     {
                         s->command = NGX_POP3_STLS;
 #endif
                     } else {
                         goto invalid;
                     }

                 } else {
                     goto invalid;
                 }

                 switch (ch) {
                 case ' ':
                     state = sw_spaces_before_argument;
                     break;
                 case CR:
                     state = sw_almost_done;
                     break;
                 case LF:
                     goto done;
                 }
                 break;
             }

             if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
                 goto invalid;
             }

             break;

         case sw_spaces_before_argument:
             switch (ch) {
             case ' ':
                 break;
             case CR:
                 state = sw_almost_done;
                 s->arg_end = p;
                 break;
             case LF:
                 s->arg_end = p;
                 goto done;
             default:
                 if (s->args.nelts <= 2) {
                     state = sw_argument;
                     s->arg_start = p;
                     break;
                 }
                 goto invalid;
             }
             break;

         case sw_argument:
             switch (ch) {

             case ' ':

                 /*
                  * the space should be considered as part of the at username
                  * or password, but not of argument in other commands
                  */

                 if (s->command == NGX_POP3_USER
                     || s->command == NGX_POP3_PASS)
                 {
                     break;
                 }

                 /* fall through */

             case CR:
             case LF:
                 arg = ngx_array_push(&s->args);
                 if (arg == NULL) {
                     return NGX_ERROR;
                 }
                 arg->len = p - s->arg_start;
                 arg->data = s->arg_start;
                 s->arg_start = NULL;

                 switch (ch) {
                 case ' ':
                     state = sw_spaces_before_argument;
                     break;
                 case CR:
                     state = sw_almost_done;
                     break;
                 case LF:
                     goto done;
                 }
                 break;

             default:
                 break;
             }
             break;

         case sw_almost_done:
             switch (ch) {
             case LF:
                 goto done;
             default:
                 goto invalid;
             }
         }
     }

     s->buffer->pos = p;
     s->state = state;

     return NGX_AGAIN;

 done:

     s->buffer->pos = p + 1;

     if (s->arg_start) {
         arg = ngx_array_push(&s->args);
         if (arg == NULL) {
             return NGX_ERROR;
         }
         arg->len = s->arg_end - s->arg_start;
         arg->data = s->arg_start;
         s->arg_start = NULL;
     }

     s->state = (s->command != NGX_POP3_AUTH) ? sw_start : sw_argument;

     return NGX_OK;

 invalid:

     s->state = sw_start;
     s->arg_start = NULL;

     return NGX_MAIL_PARSE_INVALID_COMMAND;
 }


 ngx_int_t
 ngx_mail_imap_parse_command(ngx_mail_session_t *s)
 {
     u_char      ch, *p, *c;
     ngx_str_t  *arg;
     enum {
         sw_start = 0,
         sw_spaces_before_command,
         sw_command,
         sw_spaces_before_argument,
         sw_argument,
         sw_backslash,
         sw_literal,
         sw_no_sync_literal_argument,
         sw_start_literal_argument,
         sw_literal_argument,
         sw_end_literal_argument,
         sw_almost_done
     } state;

     state = s->state;

     for (p = s->buffer->pos; p < s->buffer->last; p++) {
         ch = *p;

         switch (state) {

         /* IMAP tag */
         case sw_start:
             switch (ch) {
             case ' ':
                 s->tag.len = p - s->buffer->start + 1;
                 s->tag.data = s->buffer->start;
                 state = sw_spaces_before_command;
                 break;
             case CR:
                 s->state = sw_start;
                 return NGX_MAIL_PARSE_INVALID_COMMAND;
             case LF:
                 s->state = sw_start;
                 return NGX_MAIL_PARSE_INVALID_COMMAND;
             }
             break;

         case sw_spaces_before_command:
             switch (ch) {
             case ' ':
                 break;
             case CR:
                 s->state = sw_start;
                 return NGX_MAIL_PARSE_INVALID_COMMAND;
             case LF:
                 s->state = sw_start;
                 return NGX_MAIL_PARSE_INVALID_COMMAND;
             default:
                 s->cmd_start = p;
                 state = sw_command;
                 break;
             }
             break;

         case sw_command:
             if (ch == ' ' || ch == CR || ch == LF) {

                 c = s->cmd_start;

                 switch (p - c) {

                 case 4:
                     if ((c[0] == 'N' || c[0] == 'n')
                         && (c[1] == 'O'|| c[1] == 'o')
                         && (c[2] == 'O'|| c[2] == 'o')
                         && (c[3] == 'P'|| c[3] == 'p'))
                     {
                         s->command = NGX_IMAP_NOOP;

                     } else {
                         goto invalid;
                     }
                     break;

                 case 5:
                     if ((c[0] == 'L'|| c[0] == 'l')
                         && (c[1] == 'O'|| c[1] == 'o')
                         && (c[2] == 'G'|| c[2] == 'g')
                         && (c[3] == 'I'|| c[3] == 'i')
                         && (c[4] == 'N'|| c[4] == 'n'))
                     {
                         s->command = NGX_IMAP_LOGIN;

                     } else {
                         goto invalid;
                     }
                     break;

                 case 6:
                     if ((c[0] == 'L'|| c[0] == 'l')
                         && (c[1] == 'O'|| c[1] == 'o')
                         && (c[2] == 'G'|| c[2] == 'g')
                         && (c[3] == 'O'|| c[3] == 'o')
                         && (c[4] == 'U'|| c[4] == 'u')
                         && (c[5] == 'T'|| c[5] == 't'))
                     {
                         s->command = NGX_IMAP_LOGOUT;

                     } else {
                         goto invalid;
                     }
                     break;

 #if (NGX_MAIL_SSL)
                 case 8:
                     if ((c[0] == 'S'|| c[0] == 's')
                         && (c[1] == 'T'|| c[1] == 't')
                         && (c[2] == 'A'|| c[2] == 'a')
                         && (c[3] == 'R'|| c[3] == 'r')
                         && (c[4] == 'T'|| c[4] == 't')
                         && (c[5] == 'T'|| c[5] == 't')
                         && (c[6] == 'L'|| c[6] == 'l')
                         && (c[7] == 'S'|| c[7] == 's'))
                     {
                         s->command = NGX_IMAP_STARTTLS;

                     } else {
                         goto invalid;
                     }
                     break;
 #endif

                 case 10:
                     if ((c[0] == 'C'|| c[0] == 'c')
                         && (c[1] == 'A'|| c[1] == 'a')
                         && (c[2] == 'P'|| c[2] == 'p')
                         && (c[3] == 'A'|| c[3] == 'a')
                         && (c[4] == 'B'|| c[4] == 'b')
                         && (c[5] == 'I'|| c[5] == 'i')
                         && (c[6] == 'L'|| c[6] == 'l')
                         && (c[7] == 'I'|| c[7] == 'i')
                         && (c[8] == 'T'|| c[8] == 't')
                         && (c[9] == 'Y'|| c[9] == 'y'))
                     {
                         s->command = NGX_IMAP_CAPABILITY;

                     } else {
                         goto invalid;
                     }
                     break;

                 case 12:
                     if ((c[0] == 'A'|| c[0] == 'a')
                         && (c[1] == 'U'|| c[1] == 'u')
                         && (c[2] == 'T'|| c[2] == 't')
                         && (c[3] == 'H'|| c[3] == 'h')
                         && (c[4] == 'E'|| c[4] == 'e')
                         && (c[5] == 'N'|| c[5] == 'n')
                         && (c[6] == 'T'|| c[6] == 't')
                         && (c[7] == 'I'|| c[7] == 'i')
                         && (c[8] == 'C'|| c[8] == 'c')
                         && (c[9] == 'A'|| c[9] == 'a')
                         && (c[10] == 'T'|| c[10] == 't')
                         && (c[11] == 'E'|| c[11] == 'e'))
                     {
                         s->command = NGX_IMAP_AUTHENTICATE;

                     } else {
                         goto invalid;
                     }
                     break;

                 default:
                     goto invalid;
                 }

                 switch (ch) {
                 case ' ':
                     state = sw_spaces_before_argument;
                     break;
                 case CR:
                     state = sw_almost_done;
                     break;
                 case LF:
                     goto done;
                 }
                 break;
             }

             if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
                 goto invalid;
             }

             break;

         case sw_spaces_before_argument:
             switch (ch) {
             case ' ':
                 break;
             case CR:
                 state = sw_almost_done;
                 s->arg_end = p;
                 break;
             case LF:
                 s->arg_end = p;
                 goto done;
             case '"':
                 if (s->args.nelts <= 2) {
                     s->quoted = 1;
                     s->arg_start = p + 1;
                     state = sw_argument;
                     break;
                 }
                 goto invalid;
             case '{':
                 if (s->args.nelts <= 2) {
                     state = sw_literal;
                     break;
                 }
                 goto invalid;
             default:
                 if (s->args.nelts <= 2) {
                     s->arg_start = p;
                     state = sw_argument;
                     break;
                 }
                 goto invalid;
             }
             break;

         case sw_argument:
             if (ch == ' ' && s->quoted) {
                 break;
             }

             switch (ch) {
             case '"':
                 if (!s->quoted) {
                     break;
                 }
                 s->quoted = 0;
                 /* fall through */
             case ' ':
             case CR:
             case LF:
                 arg = ngx_array_push(&s->args);
                 if (arg == NULL) {
                     return NGX_ERROR;
                 }
                 arg->len = p - s->arg_start;
                 arg->data = s->arg_start;
                 s->arg_start = NULL;

                 switch (ch) {
                 case '"':
                 case ' ':
                     state = sw_spaces_before_argument;
                     break;
                 case CR:
                     state = sw_almost_done;
                     break;
                 case LF:
                     goto done;
                 }
                 break;
             case '\\':
                 if (s->quoted) {
                     s->backslash = 1;
                     state = sw_backslash;
                 }
                 break;
             }
             break;

         case sw_backslash:
             switch (ch) {
             case CR:
             case LF:
                 goto invalid;
             default:
                 state = sw_argument;
             }
             break;

         case sw_literal:
             if (ch >= '0' && ch <= '9') {
                 s->literal_len = s->literal_len * 10 + (ch - '0');
                 break;
             }
             if (ch == '}') {
                 state = sw_start_literal_argument;
                 break;
             }
             if (ch == '+') {
                 state = sw_no_sync_literal_argument;
                 break;
             }
             goto invalid;

         case sw_no_sync_literal_argument:
             if (ch == '}') {
                 s->no_sync_literal = 1;
                 state = sw_start_literal_argument;
                 break;
             }
             goto invalid;

         case sw_start_literal_argument:
             switch (ch) {
             case CR:
                 break;
             case LF:
                 s->buffer->pos = p + 1;
                 s->arg_start = p + 1;
                 if (s->no_sync_literal == 0) {
                     s->state = sw_literal_argument;
                     return NGX_IMAP_NEXT;
                 }
                 state = sw_literal_argument;
                 s->no_sync_literal = 0;
                 break;
             default:
                 goto invalid;
             }
             break;

         case sw_literal_argument:
             if (s->literal_len && --s->literal_len) {
                 break;
             }

             arg = ngx_array_push(&s->args);
             if (arg == NULL) {
                 return NGX_ERROR;
             }
             arg->len = p + 1 - s->arg_start;
             arg->data = s->arg_start;
             s->arg_start = NULL;
             state = sw_end_literal_argument;

             break;

         case sw_end_literal_argument:
             switch (ch) {
             case '{':
                 if (s->args.nelts <= 2) {
                     state = sw_literal;
                     break;
                 }
                 goto invalid;
             case CR:
                 state = sw_almost_done;
                 break;
             case LF:
                 goto done;
             default:
                 state = sw_spaces_before_argument;
                 break;
             }
             break;

         case sw_almost_done:
             switch (ch) {
             case LF:
                 goto done;
             default:
                 goto invalid;
             }
         }
     }

     s->buffer->pos = p;
     s->state = state;

     return NGX_AGAIN;

 done:

     s->buffer->pos = p + 1;

     if (s->arg_start) {
         arg = ngx_array_push(&s->args);
         if (arg == NULL) {
             return NGX_ERROR;
         }
         arg->len = s->arg_end - s->arg_start;
         arg->data = s->arg_start;

         s->arg_start = NULL;
         s->cmd_start = NULL;
         s->quoted = 0;
         s->no_sync_literal = 0;
         s->literal_len = 0;
     }

     s->state = (s->command != NGX_IMAP_AUTHENTICATE) ? sw_start : sw_argument;

     return NGX_OK;

 invalid:

     s->state = sw_start;
     s->quoted = 0;
     s->no_sync_literal = 0;
     s->literal_len = 0;

     return NGX_MAIL_PARSE_INVALID_COMMAND;
 }


 ngx_int_t
 ngx_mail_smtp_parse_command(ngx_mail_session_t *s)
 {
     u_char      ch, *p, *c, c0, c1, c2, c3;
     ngx_str_t  *arg;
     enum {
         sw_start = 0,
         sw_spaces_before_argument,
         sw_argument,
         sw_almost_done
     } state;

     state = s->state;

     for (p = s->buffer->pos; p < s->buffer->last; p++) {
         ch = *p;

         switch (state) {

         /* SMTP command */
         case sw_start:
             if (ch == ' ' || ch == CR || ch == LF) {
                 c = s->buffer->start;

                 if (p - c == 4) {

                     c0 = ngx_toupper(c[0]);
                     c1 = ngx_toupper(c[1]);
                     c2 = ngx_toupper(c[2]);
                     c3 = ngx_toupper(c[3]);

                     if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'O')
                     {
                         s->command = NGX_SMTP_HELO;

                     } else if (c0 == 'E' && c1 == 'H' && c2 == 'L' && c3 == 'O')
                     {
                         s->command = NGX_SMTP_EHLO;

                     } else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
                     {
                         s->command = NGX_SMTP_QUIT;

                     } else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
                     {
                         s->command = NGX_SMTP_AUTH;

                     } else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
                     {
                         s->command = NGX_SMTP_NOOP;

                     } else if (c0 == 'M' && c1 == 'A' && c2 == 'I' && c3 == 'L')
                     {
                         s->command = NGX_SMTP_MAIL;

                     } else if (c0 == 'R' && c1 == 'S' && c2 == 'E' && c3 == 'T')
                     {
                         s->command = NGX_SMTP_RSET;

                     } else if (c0 == 'R' && c1 == 'C' && c2 == 'P' && c3 == 'T')
                     {
                         s->command = NGX_SMTP_RCPT;

                     } else if (c0 == 'V' && c1 == 'R' && c2 == 'F' && c3 == 'Y')
                     {
                         s->command = NGX_SMTP_VRFY;

                     } else if (c0 == 'E' && c1 == 'X' && c2 == 'P' && c3 == 'N')
                     {
                         s->command = NGX_SMTP_EXPN;

                     } else if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'P')
                     {
                         s->command = NGX_SMTP_HELP;

                     } else {
                         goto invalid;
                     }
 #if (NGX_MAIL_SSL)
                 } else if (p - c == 8) {

                     if ((c[0] == 'S'|| c[0] == 's')
                         && (c[1] == 'T'|| c[1] == 't')
                         && (c[2] == 'A'|| c[2] == 'a')
                         && (c[3] == 'R'|| c[3] == 'r')
                         && (c[4] == 'T'|| c[4] == 't')
                         && (c[5] == 'T'|| c[5] == 't')
                         && (c[6] == 'L'|| c[6] == 'l')
                         && (c[7] == 'S'|| c[7] == 's'))
                     {
                         s->command = NGX_SMTP_STARTTLS;

                     } else {
                         goto invalid;
                     }
 #endif
                 } else {
                     goto invalid;
                 }

                 switch (ch) {
                 case ' ':
                     state = sw_spaces_before_argument;
                     break;
                 case CR:
                     state = sw_almost_done;
                     break;
                 case LF:
                     goto done;
                 }
                 break;
             }

             if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
                 goto invalid;
             }

             break;

         case sw_spaces_before_argument:
             switch (ch) {
             case ' ':
                 break;
             case CR:
                 state = sw_almost_done;
                 s->arg_end = p;
                 break;
             case LF:
                 s->arg_end = p;
                 goto done;
             default:
                 if (s->args.nelts <= 10) {
                     state = sw_argument;
                     s->arg_start = p;
                     break;
                 }
                 goto invalid;
             }
             break;

         case sw_argument:
             switch (ch) {
             case ' ':
             case CR:
             case LF:
                 arg = ngx_array_push(&s->args);
                 if (arg == NULL) {
                     return NGX_ERROR;
                 }
                 arg->len = p - s->arg_start;
                 arg->data = s->arg_start;
                 s->arg_start = NULL;

                 switch (ch) {
                 case ' ':
                     state = sw_spaces_before_argument;
                     break;
                 case CR:
                     state = sw_almost_done;
                     break;
                 case LF:
                     goto done;
                 }
                 break;

             default:
                 break;
             }
             break;

         case sw_almost_done:
             switch (ch) {
             case LF:
                 goto done;
             default:
                 goto invalid;
             }
         }
     }

     s->buffer->pos = p;
     s->state = state;

     return NGX_AGAIN;

 done:

     s->buffer->pos = p + 1;

     if (s->arg_start) {
         arg = ngx_array_push(&s->args);
         if (arg == NULL) {
             return NGX_ERROR;
         }
         arg->len = s->arg_end - s->arg_start;
         arg->data = s->arg_start;
         s->arg_start = NULL;
     }

     s->state = (s->command != NGX_SMTP_AUTH) ? sw_start : sw_argument;

     return NGX_OK;

 invalid:

     s->state = sw_start;
     s->arg_start = NULL;

     return NGX_MAIL_PARSE_INVALID_COMMAND;
 }


 ngx_int_t
 ngx_mail_auth_parse(ngx_mail_session_t *s, ngx_connection_t *c)
 {
     ngx_str_t                 *arg;

 #if (NGX_MAIL_SSL)
     if (ngx_mail_starttls_only(s, c)) {
         return NGX_MAIL_PARSE_INVALID_COMMAND;
     }
 #endif

     arg = s->args.elts;

     if (arg[0].len == 5) {

         if (ngx_strncasecmp(arg[0].data, (u_char *) "LOGIN", 5) == 0) {

             if (s->args.nelts == 1) {
                 return NGX_MAIL_AUTH_LOGIN;
             }

             if (s->args.nelts == 2) {
                 return NGX_MAIL_AUTH_LOGIN_USERNAME;
             }

             return NGX_MAIL_PARSE_INVALID_COMMAND;
         }

         if (ngx_strncasecmp(arg[0].data, (u_char *) "PLAIN", 5) == 0) {

             if (s->args.nelts == 1) {
                 return NGX_MAIL_AUTH_PLAIN;
             }

             if (s->args.nelts == 2) {
                 return ngx_mail_auth_plain(s, c, 1);
             }
         }

         return NGX_MAIL_PARSE_INVALID_COMMAND;
     }

     if (arg[0].len == 8) {

         if (s->args.nelts != 1) {
             return NGX_MAIL_PARSE_INVALID_COMMAND;
         }

         if (ngx_strncasecmp(arg[0].data, (u_char *) "CRAM-MD5", 8) == 0) {
             return NGX_MAIL_AUTH_CRAM_MD5;
         }
     }

     return NGX_MAIL_PARSE_INVALID_COMMAND;
 }

	/*
	* Copyright (C) Igor Sysoev
	*/


	#include <ngx_config.h>
	#include <ngx_core.h>
	#include <ngx_event.h>
	#include <ngx_mail.h>


	ngx_int_t
	ngx_mail_pop3_parse_command(ngx_mail_session_t *s)
	{
	u_char ch, p, c, c0, c1, c2, c3;
	ngx_str_t *arg;
	enum {
	sw_start = 0,
	sw_spaces_before_argument,
	sw_argument,
	sw_almost_done
	} state;

	state = s->state;

	for (p = s->buffer->pos; p < s->buffer->last; p++) {
	ch = *p;

	switch (state) {

	/* POP3 command */
	case sw_start:
	if (ch == ' ' \|\| ch == CR \|\| ch == LF) {
	c = s->buffer->start;

	if (p - c == 4) {

	c0 = ngx_toupper(c[0]);
	c1 = ngx_toupper(c[1]);
	c2 = ngx_toupper(c[2]);
	c3 = ngx_toupper(c[3]);

	if (c0 == 'U' && c1 == 'S' && c2 == 'E' && c3 == 'R')
	{
	s->command = NGX_POP3_USER;

	} else if (c0 == 'P' && c1 == 'A' && c2 == 'S' && c3 == 'S')
	{
	s->command = NGX_POP3_PASS;

	} else if (c0 == 'A' && c1 == 'P' && c2 == 'O' && c3 == 'P')
	{
	s->command = NGX_POP3_APOP;

	} else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
	{
	s->command = NGX_POP3_QUIT;

	} else if (c0 == 'C' && c1 == 'A' && c2 == 'P' && c3 == 'A')
	{
	s->command = NGX_POP3_CAPA;

	} else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
	{
	s->command = NGX_POP3_AUTH;

	} else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
	{
	s->command = NGX_POP3_NOOP;
	#if (NGX_MAIL_SSL)
	} else if (c0 == 'S' && c1 == 'T' && c2 == 'L' && c3 == 'S')
	{
	s->command = NGX_POP3_STLS;
	#endif
	} else {
	goto invalid;
	}

	} else {
	goto invalid;
	}

	switch (ch) {
	case ' ':
	state = sw_spaces_before_argument;
	break;
	case CR:
	state = sw_almost_done;
	break;
	case LF:
	goto done;
	}
	break;
	}

	if ((ch < 'A' \|\| ch > 'Z') && (ch < 'a' \|\| ch > 'z')) {
	goto invalid;
	}

	break;

	case sw_spaces_before_argument:
	switch (ch) {
	case ' ':
	break;
	case CR:
	state = sw_almost_done;
	s->arg_end = p;
	break;
	case LF:
	s->arg_end = p;
	goto done;
	default:
	if (s->args.nelts <= 2) {
	state = sw_argument;
	s->arg_start = p;
	break;
	}
	goto invalid;
	}
	break;

	case sw_argument:
	switch (ch) {

	case ' ':

	/*
	* the space should be considered as part of the at username
	* or password, but not of argument in other commands
	*/

	if (s->command == NGX_POP3_USER
	\|\| s->command == NGX_POP3_PASS)
	{
	break;
	}

	/* fall through */

	case CR:
	case LF:
	arg = ngx_array_push(&s->args);
	if (arg == NULL) {
	return NGX_ERROR;
	}
	arg->len = p - s->arg_start;
	arg->data = s->arg_start;
	s->arg_start = NULL;

	switch (ch) {
	case ' ':
	state = sw_spaces_before_argument;
	break;
	case CR:
	state = sw_almost_done;
	break;
	case LF:
	goto done;
	}
	break;

	default:
	break;
	}
	break;

	case sw_almost_done:
	switch (ch) {
	case LF:
	goto done;
	default:
	goto invalid;
	}
	}
	}

	s->buffer->pos = p;
	s->state = state;

	return NGX_AGAIN;

	done:

	s->buffer->pos = p + 1;

	if (s->arg_start) {
	arg = ngx_array_push(&s->args);
	if (arg == NULL) {
	return NGX_ERROR;
	}
	arg->len = s->arg_end - s->arg_start;
	arg->data = s->arg_start;
	s->arg_start = NULL;
	}

	s->state = (s->command != NGX_POP3_AUTH) ? sw_start : sw_argument;

	return NGX_OK;

	invalid:

	s->state = sw_start;
	s->arg_start = NULL;

	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}


	ngx_int_t
	ngx_mail_imap_parse_command(ngx_mail_session_t *s)
	{
	u_char ch, p, c;
	ngx_str_t *arg;
	enum {
	sw_start = 0,
	sw_spaces_before_command,
	sw_command,
	sw_spaces_before_argument,
	sw_argument,
	sw_backslash,
	sw_literal,
	sw_no_sync_literal_argument,
	sw_start_literal_argument,
	sw_literal_argument,
	sw_end_literal_argument,
	sw_almost_done
	} state;

	state = s->state;

	for (p = s->buffer->pos; p < s->buffer->last; p++) {
	ch = *p;

	switch (state) {

	/* IMAP tag */
	case sw_start:
	switch (ch) {
	case ' ':
	s->tag.len = p - s->buffer->start + 1;
	s->tag.data = s->buffer->start;
	state = sw_spaces_before_command;
	break;
	case CR:
	s->state = sw_start;
	return NGX_MAIL_PARSE_INVALID_COMMAND;
	case LF:
	s->state = sw_start;
	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}
	break;

	case sw_spaces_before_command:
	switch (ch) {
	case ' ':
	break;
	case CR:
	s->state = sw_start;
	return NGX_MAIL_PARSE_INVALID_COMMAND;
	case LF:
	s->state = sw_start;
	return NGX_MAIL_PARSE_INVALID_COMMAND;
	default:
	s->cmd_start = p;
	state = sw_command;
	break;
	}
	break;

	case sw_command:
	if (ch == ' ' \|\| ch == CR \|\| ch == LF) {

	c = s->cmd_start;

	switch (p - c) {

	case 4:
	if ((c[0] == 'N' \|\| c[0] == 'n')
	&& (c[1] == 'O'\|\| c[1] == 'o')
	&& (c[2] == 'O'\|\| c[2] == 'o')
	&& (c[3] == 'P'\|\| c[3] == 'p'))
	{
	s->command = NGX_IMAP_NOOP;

	} else {
	goto invalid;
	}
	break;

	case 5:
	if ((c[0] == 'L'\|\| c[0] == 'l')
	&& (c[1] == 'O'\|\| c[1] == 'o')
	&& (c[2] == 'G'\|\| c[2] == 'g')
	&& (c[3] == 'I'\|\| c[3] == 'i')
	&& (c[4] == 'N'\|\| c[4] == 'n'))
	{
	s->command = NGX_IMAP_LOGIN;

	} else {
	goto invalid;
	}
	break;

	case 6:
	if ((c[0] == 'L'\|\| c[0] == 'l')
	&& (c[1] == 'O'\|\| c[1] == 'o')
	&& (c[2] == 'G'\|\| c[2] == 'g')
	&& (c[3] == 'O'\|\| c[3] == 'o')
	&& (c[4] == 'U'\|\| c[4] == 'u')
	&& (c[5] == 'T'\|\| c[5] == 't'))
	{
	s->command = NGX_IMAP_LOGOUT;

	} else {
	goto invalid;
	}
	break;

	#if (NGX_MAIL_SSL)
	case 8:
	if ((c[0] == 'S'\|\| c[0] == 's')
	&& (c[1] == 'T'\|\| c[1] == 't')
	&& (c[2] == 'A'\|\| c[2] == 'a')
	&& (c[3] == 'R'\|\| c[3] == 'r')
	&& (c[4] == 'T'\|\| c[4] == 't')
	&& (c[5] == 'T'\|\| c[5] == 't')
	&& (c[6] == 'L'\|\| c[6] == 'l')
	&& (c[7] == 'S'\|\| c[7] == 's'))
	{
	s->command = NGX_IMAP_STARTTLS;

	} else {
	goto invalid;
	}
	break;
	#endif

	case 10:
	if ((c[0] == 'C'\|\| c[0] == 'c')
	&& (c[1] == 'A'\|\| c[1] == 'a')
	&& (c[2] == 'P'\|\| c[2] == 'p')
	&& (c[3] == 'A'\|\| c[3] == 'a')
	&& (c[4] == 'B'\|\| c[4] == 'b')
	&& (c[5] == 'I'\|\| c[5] == 'i')
	&& (c[6] == 'L'\|\| c[6] == 'l')
	&& (c[7] == 'I'\|\| c[7] == 'i')
	&& (c[8] == 'T'\|\| c[8] == 't')
	&& (c[9] == 'Y'\|\| c[9] == 'y'))
	{
	s->command = NGX_IMAP_CAPABILITY;

	} else {
	goto invalid;
	}
	break;

	case 12:
	if ((c[0] == 'A'\|\| c[0] == 'a')
	&& (c[1] == 'U'\|\| c[1] == 'u')
	&& (c[2] == 'T'\|\| c[2] == 't')
	&& (c[3] == 'H'\|\| c[3] == 'h')
	&& (c[4] == 'E'\|\| c[4] == 'e')
	&& (c[5] == 'N'\|\| c[5] == 'n')
	&& (c[6] == 'T'\|\| c[6] == 't')
	&& (c[7] == 'I'\|\| c[7] == 'i')
	&& (c[8] == 'C'\|\| c[8] == 'c')
	&& (c[9] == 'A'\|\| c[9] == 'a')
	&& (c[10] == 'T'\|\| c[10] == 't')
	&& (c[11] == 'E'\|\| c[11] == 'e'))
	{
	s->command = NGX_IMAP_AUTHENTICATE;

	} else {
	goto invalid;
	}
	break;

	default:
	goto invalid;
	}

	switch (ch) {
	case ' ':
	state = sw_spaces_before_argument;
	break;
	case CR:
	state = sw_almost_done;
	break;
	case LF:
	goto done;
	}
	break;
	}

	if ((ch < 'A' \|\| ch > 'Z') && (ch < 'a' \|\| ch > 'z')) {
	goto invalid;
	}

	break;

	case sw_spaces_before_argument:
	switch (ch) {
	case ' ':
	break;
	case CR:
	state = sw_almost_done;
	s->arg_end = p;
	break;
	case LF:
	s->arg_end = p;
	goto done;
	case '"':
	if (s->args.nelts <= 2) {
	s->quoted = 1;
	s->arg_start = p + 1;
	state = sw_argument;
	break;
	}
	goto invalid;
	case '{':
	if (s->args.nelts <= 2) {
	state = sw_literal;
	break;
	}
	goto invalid;
	default:
	if (s->args.nelts <= 2) {
	s->arg_start = p;
	state = sw_argument;
	break;
	}
	goto invalid;
	}
	break;

	case sw_argument:
	if (ch == ' ' && s->quoted) {
	break;
	}

	switch (ch) {
	case '"':
	if (!s->quoted) {
	break;
	}
	s->quoted = 0;
	/* fall through */
	case ' ':
	case CR:
	case LF:
	arg = ngx_array_push(&s->args);
	if (arg == NULL) {
	return NGX_ERROR;
	}
	arg->len = p - s->arg_start;
	arg->data = s->arg_start;
	s->arg_start = NULL;

	switch (ch) {
	case '"':
	case ' ':
	state = sw_spaces_before_argument;
	break;
	case CR:
	state = sw_almost_done;
	break;
	case LF:
	goto done;
	}
	break;
	case '\\':
	if (s->quoted) {
	s->backslash = 1;
	state = sw_backslash;
	}
	break;
	}
	break;

	case sw_backslash:
	switch (ch) {
	case CR:
	case LF:
	goto invalid;
	default:
	state = sw_argument;
	}
	break;

	case sw_literal:
	if (ch >= '0' && ch <= '9') {
	s->literal_len = s->literal_len * 10 + (ch - '0');
	break;
	}
	if (ch == '}') {
	state = sw_start_literal_argument;
	break;
	}
	if (ch == '+') {
	state = sw_no_sync_literal_argument;
	break;
	}
	goto invalid;

	case sw_no_sync_literal_argument:
	if (ch == '}') {
	s->no_sync_literal = 1;
	state = sw_start_literal_argument;
	break;
	}
	goto invalid;

	case sw_start_literal_argument:
	switch (ch) {
	case CR:
	break;
	case LF:
	s->buffer->pos = p + 1;
	s->arg_start = p + 1;
	if (s->no_sync_literal == 0) {
	s->state = sw_literal_argument;
	return NGX_IMAP_NEXT;
	}
	state = sw_literal_argument;
	s->no_sync_literal = 0;
	break;
	default:
	goto invalid;
	}
	break;

	case sw_literal_argument:
	if (s->literal_len && --s->literal_len) {
	break;
	}

	arg = ngx_array_push(&s->args);
	if (arg == NULL) {
	return NGX_ERROR;
	}
	arg->len = p + 1 - s->arg_start;
	arg->data = s->arg_start;
	s->arg_start = NULL;
	state = sw_end_literal_argument;

	break;

	case sw_end_literal_argument:
	switch (ch) {
	case '{':
	if (s->args.nelts <= 2) {
	state = sw_literal;
	break;
	}
	goto invalid;
	case CR:
	state = sw_almost_done;
	break;
	case LF:
	goto done;
	default:
	state = sw_spaces_before_argument;
	break;
	}
	break;

	case sw_almost_done:
	switch (ch) {
	case LF:
	goto done;
	default:
	goto invalid;
	}
	}
	}

	s->buffer->pos = p;
	s->state = state;

	return NGX_AGAIN;

	done:

	s->buffer->pos = p + 1;

	if (s->arg_start) {
	arg = ngx_array_push(&s->args);
	if (arg == NULL) {
	return NGX_ERROR;
	}
	arg->len = s->arg_end - s->arg_start;
	arg->data = s->arg_start;

	s->arg_start = NULL;
	s->cmd_start = NULL;
	s->quoted = 0;
	s->no_sync_literal = 0;
	s->literal_len = 0;
	}

	s->state = (s->command != NGX_IMAP_AUTHENTICATE) ? sw_start : sw_argument;

	return NGX_OK;

	invalid:

	s->state = sw_start;
	s->quoted = 0;
	s->no_sync_literal = 0;
	s->literal_len = 0;

	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}


	ngx_int_t
	ngx_mail_smtp_parse_command(ngx_mail_session_t *s)
	{
	u_char ch, p, c, c0, c1, c2, c3;
	ngx_str_t *arg;
	enum {
	sw_start = 0,
	sw_spaces_before_argument,
	sw_argument,
	sw_almost_done
	} state;

	state = s->state;

	for (p = s->buffer->pos; p < s->buffer->last; p++) {
	ch = *p;

	switch (state) {

	/* SMTP command */
	case sw_start:
	if (ch == ' ' \|\| ch == CR \|\| ch == LF) {
	c = s->buffer->start;

	if (p - c == 4) {

	c0 = ngx_toupper(c[0]);
	c1 = ngx_toupper(c[1]);
	c2 = ngx_toupper(c[2]);
	c3 = ngx_toupper(c[3]);

	if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'O')
	{
	s->command = NGX_SMTP_HELO;

	} else if (c0 == 'E' && c1 == 'H' && c2 == 'L' && c3 == 'O')
	{
	s->command = NGX_SMTP_EHLO;

	} else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
	{
	s->command = NGX_SMTP_QUIT;

	} else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
	{
	s->command = NGX_SMTP_AUTH;

	} else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
	{
	s->command = NGX_SMTP_NOOP;

	} else if (c0 == 'M' && c1 == 'A' && c2 == 'I' && c3 == 'L')
	{
	s->command = NGX_SMTP_MAIL;

	} else if (c0 == 'R' && c1 == 'S' && c2 == 'E' && c3 == 'T')
	{
	s->command = NGX_SMTP_RSET;

	} else if (c0 == 'R' && c1 == 'C' && c2 == 'P' && c3 == 'T')
	{
	s->command = NGX_SMTP_RCPT;

	} else if (c0 == 'V' && c1 == 'R' && c2 == 'F' && c3 == 'Y')
	{
	s->command = NGX_SMTP_VRFY;

	} else if (c0 == 'E' && c1 == 'X' && c2 == 'P' && c3 == 'N')
	{
	s->command = NGX_SMTP_EXPN;

	} else if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'P')
	{
	s->command = NGX_SMTP_HELP;

	} else {
	goto invalid;
	}
	#if (NGX_MAIL_SSL)
	} else if (p - c == 8) {

	if ((c[0] == 'S'\|\| c[0] == 's')
	&& (c[1] == 'T'\|\| c[1] == 't')
	&& (c[2] == 'A'\|\| c[2] == 'a')
	&& (c[3] == 'R'\|\| c[3] == 'r')
	&& (c[4] == 'T'\|\| c[4] == 't')
	&& (c[5] == 'T'\|\| c[5] == 't')
	&& (c[6] == 'L'\|\| c[6] == 'l')
	&& (c[7] == 'S'\|\| c[7] == 's'))
	{
	s->command = NGX_SMTP_STARTTLS;

	} else {
	goto invalid;
	}
	#endif
	} else {
	goto invalid;
	}

	switch (ch) {
	case ' ':
	state = sw_spaces_before_argument;
	break;
	case CR:
	state = sw_almost_done;
	break;
	case LF:
	goto done;
	}
	break;
	}

	if ((ch < 'A' \|\| ch > 'Z') && (ch < 'a' \|\| ch > 'z')) {
	goto invalid;
	}

	break;

	case sw_spaces_before_argument:
	switch (ch) {
	case ' ':
	break;
	case CR:
	state = sw_almost_done;
	s->arg_end = p;
	break;
	case LF:
	s->arg_end = p;
	goto done;
	default:
	if (s->args.nelts <= 10) {
	state = sw_argument;
	s->arg_start = p;
	break;
	}
	goto invalid;
	}
	break;

	case sw_argument:
	switch (ch) {
	case ' ':
	case CR:
	case LF:
	arg = ngx_array_push(&s->args);
	if (arg == NULL) {
	return NGX_ERROR;
	}
	arg->len = p - s->arg_start;
	arg->data = s->arg_start;
	s->arg_start = NULL;

	switch (ch) {
	case ' ':
	state = sw_spaces_before_argument;
	break;
	case CR:
	state = sw_almost_done;
	break;
	case LF:
	goto done;
	}
	break;

	default:
	break;
	}
	break;

	case sw_almost_done:
	switch (ch) {
	case LF:
	goto done;
	default:
	goto invalid;
	}
	}
	}

	s->buffer->pos = p;
	s->state = state;

	return NGX_AGAIN;

	done:

	s->buffer->pos = p + 1;

	if (s->arg_start) {
	arg = ngx_array_push(&s->args);
	if (arg == NULL) {
	return NGX_ERROR;
	}
	arg->len = s->arg_end - s->arg_start;
	arg->data = s->arg_start;
	s->arg_start = NULL;
	}

	s->state = (s->command != NGX_SMTP_AUTH) ? sw_start : sw_argument;

	return NGX_OK;

	invalid:

	s->state = sw_start;
	s->arg_start = NULL;

	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}


	ngx_int_t
	ngx_mail_auth_parse(ngx_mail_session_t s, ngx_connection_t c)
	{
	ngx_str_t *arg;

	#if (NGX_MAIL_SSL)
	if (ngx_mail_starttls_only(s, c)) {
	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}
	#endif

	arg = s->args.elts;

	if (arg[0].len == 5) {

	if (ngx_strncasecmp(arg[0].data, (u_char *) "LOGIN", 5) == 0) {

	if (s->args.nelts == 1) {
	return NGX_MAIL_AUTH_LOGIN;
	}

	if (s->args.nelts == 2) {
	return NGX_MAIL_AUTH_LOGIN_USERNAME;
	}

	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}

	if (ngx_strncasecmp(arg[0].data, (u_char *) "PLAIN", 5) == 0) {

	if (s->args.nelts == 1) {
	return NGX_MAIL_AUTH_PLAIN;
	}

	if (s->args.nelts == 2) {
	return ngx_mail_auth_plain(s, c, 1);
	}
	}

	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}

	if (arg[0].len == 8) {

	if (s->args.nelts != 1) {
	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}

	if (ngx_strncasecmp(arg[0].data, (u_char *) "CRAM-MD5", 8) == 0) {
	return NGX_MAIL_AUTH_CRAM_MD5;
	}
	}

	return NGX_MAIL_PARSE_INVALID_COMMAND;
	}