src/lib-mail/mail-user-hash.c

	mail-user-hash.c revision acfda38b75d0f0e899ef692fef01593bd56ed85e
/* Copyright (c) 2013-2016 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "md5.h"
#include "str.h"
#include "var-expand.h"
#include "mail-user-hash.h"

unsigned int mail_user_hash(const char *username, const char *format)
{
    unsigned char md5[MD5_RESULTLEN];
    unsigned int i, hash = 0;

    if (strcmp(format, "%u") == 0) {
        /* fast path */
        md5_get_digest(username, strlen(username), md5);
    } else if (strcmp(format, "%Lu") == 0) {
        /* almost as fast path */
        T_BEGIN {
            md5_get_digest(t_str_lcase(username),
                       strlen(username), md5);
        } T_END;
    } else T_BEGIN {
        const struct var_expand_table tab[] = {
            { 'u', username, "user" },
            { 'n', t_strcut(username, '@'), "username" },
            { 'd', i_strchr_to_next(username, '@'), "domain" },
            { '\0', NULL, NULL }
        };
        string_t *str = t_str_new(128);

        var_expand(str, format, tab);
        md5_get_digest(str_data(str), str_len(str), md5);
    } T_END;
    for (i = 0; i < sizeof(hash); i++)
        hash = (hash << CHAR_BIT) | md5[i];
    return hash;
}