diff options
Diffstat (limited to 'main/utils.c')
| -rw-r--r-- | main/utils.c | 173 |
1 files changed, 170 insertions, 3 deletions
diff --git a/main/utils.c b/main/utils.c index 100725487..208a4d326 100644 --- a/main/utils.c +++ b/main/utils.c @@ -32,12 +32,14 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #include <ctype.h> +#include <fcntl.h> #include <sys/stat.h> #include <sys/stat.h> - -#include <fcntl.h> - #include <sys/syscall.h> +#include <unistd.h> +#if defined(HAVE_CRYPT_R) +#include <crypt.h> +#endif #if defined(__APPLE__) #include <mach/mach.h> #elif defined(HAVE_SYS_THR_H) @@ -2271,6 +2273,171 @@ int ast_get_tid(void) return ret; } +/*! + * \brief Max length of a salt string. + * + * $[1,5,6]$[a–zA–Z0–9./]{1,16}$, plus null terminator + */ +#define MAX_SALT_LEN 21 + +static char salt_chars[] = + "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "0123456789" + "./"; + +/*! Randomly select a character for a salt string */ +static char gen_salt_char(void) +{ + int which = ast_random_double() * 64; + return salt_chars[which]; +} + +/*! + * \brief Generates a salt to try with crypt. + * + * If given an empty string, will generate a salt for the most secure algorithm + * to try with crypt(). If given a previously generated salt, the algorithm will + * be lowered by one level of security. + * + * \param[out] current_salt Output string in which to generate the salt. + * This can be an empty string, or the results of a + * prior gen_salt call. + * \param max_len Length of \a current_salt. + * \return 0 on success. + * \return Non-zero on error. + */ +static int gen_salt(char *current_salt, size_t maxlen) +{ + int i; + + if (maxlen < MAX_SALT_LEN || current_salt == NULL) { + return -1; + } + + switch (current_salt[0]) { + case '\0': + /* Initial generation; $6$ = SHA-512 */ + *current_salt++ = '$'; + *current_salt++ = '6'; + *current_salt++ = '$'; + for (i = 0; i < 16; ++i) { + *current_salt++ = gen_salt_char(); + } + *current_salt++ = '$'; + *current_salt++ = '\0'; + return 0; + case '$': + switch (current_salt[1]) { + case '6': + /* Downgrade to SHA-256 */ + current_salt[1] = '5'; + return 0; + case '5': + /* Downgrade to MD5 */ + current_salt[1] = '1'; + return 0; + case '1': + /* Downgrade to traditional crypt */ + *current_salt++ = gen_salt_char(); + *current_salt++ = gen_salt_char(); + *current_salt++ = '\0'; + return 0; + default: + /* Unrecognized algorithm */ + return -1; + } + default: + /* Was already as insecure as it gets */ + return -1; + } + +} + +#if defined(HAVE_CRYPT_R) + +char *ast_crypt(const char *key, const char *salt) +{ + struct crypt_data data = {}; + const char *crypted = crypt_r(key, salt, &data); + + /* Crypt may return success even if it doesn't recognize the salt. But + * in those cases it always mangles the salt in some way. + */ + if (!crypted || !ast_begins_with(crypted, salt)) { + return NULL; + } + + return ast_strdup(crypted); +} + +int ast_crypt_validate(const char *key, const char *expected) +{ + struct crypt_data data = {}; + return strcmp(expected, crypt_r(key, expected, &data)) == 0; +} + +#elif defined(HAVE_CRYPT) + +/* crypt is not reentrant. A global mutex is neither ideal nor perfect, but good + * enough if crypt_r support is unavailable + */ +AST_MUTEX_DEFINE_STATIC(crypt_mutex); + +char *ast_crypt(const char *key, const char *salt) +{ + const char *crypted; + SCOPED_MUTEX(lock, &crypt_mutex); + + crypted = crypt(key, salt); + + /* Crypt may return success even if it doesn't recognize the salt. But + * in those cases it always mangles the salt in some way. + */ + if (!crypted || !ast_begins_with(crypted, salt)) { + return NULL; + } + + return ast_strdup(crypted); +} + +int ast_crypt_validate(const char *key, const char *expected) +{ + SCOPED_MUTEX(lock, &crypt_mutex); + return strcmp(expected, crypt(key, expected)) == 0; +} + +#else /* No crypt support */ + +char *ast_crypt(const char *key, const char *salt) +{ + ast_log(LOG_WARNING, + "crypt() support not available; cannot encrypt password\n"); + return NULL; +} + +int ast_crypt_validate(const char *key, const char *expected) +{ + ast_log(LOG_WARNING, + "crypt() support not available; cannot validate password\n"); + return 0; +} + +#endif /* No crypt support */ + +char *ast_crypt_encrypt(const char *key) +{ + char salt[MAX_SALT_LEN] = {}; + while (gen_salt(salt, sizeof(salt)) == 0) { + char *crypted = ast_crypt(key, salt); + if (crypted) { + return crypted; + } + } + return NULL; +} + + char *ast_utils_which(const char *binary, char *fullpath, size_t fullpath_size) { const char *envPATH = getenv("PATH"); |