diff options
Diffstat (limited to 'src/lib/crypto/krb/dk/stringtokey.c')
-rw-r--r-- | src/lib/crypto/krb/dk/stringtokey.c | 65 |
1 files changed, 63 insertions, 2 deletions
diff --git a/src/lib/crypto/krb/dk/stringtokey.c b/src/lib/crypto/krb/dk/stringtokey.c index ff436e6..9a49187 100644 --- a/src/lib/crypto/krb/dk/stringtokey.c +++ b/src/lib/crypto/krb/dk/stringtokey.c @@ -31,10 +31,11 @@ static const unsigned char kerberos[] = "kerberos"; #define kerberos_len (sizeof(kerberos)-1) krb5_error_code -krb5int_dk_string_to_key(const struct krb5_enc_provider *enc, +krb5int_dk_string_to_key(const struct krb5_keytypes *ktp, const krb5_data *string, const krb5_data *salt, const krb5_data *parms, krb5_keyblock *keyblock) { + const struct krb5_enc_provider *enc = ktp->enc; krb5_error_code ret; size_t keybytes, keylength, concatlen; unsigned char *concat = NULL, *foldstring = NULL, *foldkeydata = NULL; @@ -72,7 +73,7 @@ krb5int_dk_string_to_key(const struct krb5_enc_provider *enc, foldkeyblock.length = keylength; foldkeyblock.contents = foldkeydata; - ret = (*enc->make_key)(&indata, &foldkeyblock); + ret = enc->make_key(&indata, &foldkeyblock); if (ret != 0) goto cleanup; @@ -96,3 +97,63 @@ cleanup: krb5_k_free_key(NULL, foldkey); return ret; } + + +#define DEFAULT_ITERATION_COUNT 4096 /* was 0xb000L in earlier drafts */ +#define MAX_ITERATION_COUNT 0x1000000L + +krb5_error_code +krb5int_aes_string_to_key(const struct krb5_keytypes *ktp, + const krb5_data *string, + const krb5_data *salt, + const krb5_data *params, + krb5_keyblock *key) +{ + unsigned long iter_count; + krb5_data out; + static const krb5_data usage = { KV5M_DATA, 8, "kerberos" }; + krb5_key tempkey = NULL; + krb5_error_code err; + + if (params) { + unsigned char *p = (unsigned char *) params->data; + if (params->length != 4) + return KRB5_ERR_BAD_S2K_PARAMS; + /* The first two need casts in case 'int' is 16 bits. */ + iter_count = load_32_be(p); + if (iter_count == 0) { + iter_count = (1UL << 16) << 16; + if (((iter_count >> 16) >> 16) != 1) + return KRB5_ERR_BAD_S2K_PARAMS; + } + } else + iter_count = DEFAULT_ITERATION_COUNT; + + /* This is not a protocol specification constraint; this is an + implementation limit, which should eventually be controlled by + a config file. */ + if (iter_count >= MAX_ITERATION_COUNT) + return KRB5_ERR_BAD_S2K_PARAMS; + + /* Use the output keyblock contents for temporary space. */ + out.data = (char *) key->contents; + out.length = key->length; + if (out.length != 16 && out.length != 32) + return KRB5_CRYPTO_INTERNAL; + + err = krb5int_pbkdf2_hmac_sha1 (&out, iter_count, string, salt); + if (err) + goto cleanup; + + err = krb5_k_create_key (NULL, key, &tempkey); + if (err) + goto cleanup; + + err = krb5int_derive_keyblock(ktp->enc, tempkey, key, &usage); + +cleanup: + if (err) + memset (out.data, 0, out.length); + krb5_k_free_key (NULL, tempkey); + return err; +} |