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Diffstat (limited to 'contrib/ntp/libntp/authusekey.c')
-rw-r--r-- | contrib/ntp/libntp/authusekey.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/contrib/ntp/libntp/authusekey.c b/contrib/ntp/libntp/authusekey.c new file mode 100644 index 0000000..a399a48 --- /dev/null +++ b/contrib/ntp/libntp/authusekey.c @@ -0,0 +1,134 @@ +/* + * authusekey - decode a key from ascii and use it + */ +#include <stdio.h> +#include <ctype.h> + +#include "ntp_types.h" +#include "ntp_string.h" +#include "ntp_stdlib.h" + +/* + * Types of ascii representations for keys. "Standard" means a 64 bit + * hex number in NBS format, i.e. with the low order bit of each byte + * a parity bit. "NTP" means a 64 bit key in NTP format, with the + * high order bit of each byte a parity bit. "Ascii" means a 1-to-8 + * character string whose ascii representation is used as the key. + */ +#ifdef DES +#define KEY_TYPE_STD 1 +#define KEY_TYPE_NTP 2 +#define KEY_TYPE_ASCII 3 + +#define STD_PARITY_BITS ((unsigned)0x01010101) + +#endif + +#ifdef MD5 +#define KEY_TYPE_MD5 4 +#endif + +int +authusekey( + u_long keyno, + int keytype, + const u_char *str + ) +{ +#ifdef DES + u_int32 key[2]; + u_char keybytes[8]; + char *xdigit; + int i; + static const char *hex = "0123456789abcdef"; +#endif + const u_char *cp; + int len; + + cp = str; + len = strlen((const char *)cp); + if (len == 0) + return 0; + + switch(keytype) { +#ifdef DES + case KEY_TYPE_STD: + case KEY_TYPE_NTP: + if (len != 16) /* Lazy. Should define constant */ + return 0; + /* + * Decode hex key. + */ + key[0] = 0; + key[1] = 0; + for (i = 0; i < 16; i++) { + if (!isascii(*cp)) + return 0; + xdigit = strchr(hex, isupper(*cp) ? tolower(*cp) : *cp); + cp++; + if (xdigit == 0) + return 0; + key[i>>3] <<= 4; + key[i>>3] |= (u_int32)(xdigit - hex) & 0xf; + } + + /* + * If this is an NTP format key, put it into NBS format + */ + if (keytype == KEY_TYPE_NTP) { + for (i = 0; i < 2; i++) + key[i] = ((key[i] << 1) & ~STD_PARITY_BITS) + | ((key[i] >> 7) & STD_PARITY_BITS); + } + + /* + * Check the parity, reject the key if the check fails + */ + if (!DESauth_parity(key)) { + return 0; + } + + /* + * We can't find a good reason not to use this key. + * So use it. + */ + DESauth_setkey(keyno, key); + break; + + case KEY_TYPE_ASCII: + /* + * Make up key from ascii representation + */ + memset((char *) keybytes, 0, sizeof(keybytes)); + for (i = 0; i < 8 && i < len; i++) + keybytes[i] = *cp++ << 1; + key[0] = (u_int32)keybytes[0] << 24 | (u_int32)keybytes[1] << 16 + | (u_int32)keybytes[2] << 8 | (u_int32)keybytes[3]; + key[1] = (u_int32)keybytes[4] << 24 | (u_int32)keybytes[5] << 16 + | (u_int32)keybytes[6] << 8 | (u_int32)keybytes[7]; + + /* + * Set parity on key + */ + (void)DESauth_parity(key); + + /* + * Now set key in. + */ + DESauth_setkey(keyno, key); + break; +#endif + +#ifdef MD5 + case KEY_TYPE_MD5: + MD5auth_setkey(keyno, str, (int)strlen((const char *)str)); + break; +#endif + + default: + /* Oh, well */ + return 0; + } + + return 1; +} |