diff options
Diffstat (limited to 'src/lib/crypto/krb/crypto_length.c')
| -rw-r--r-- | src/lib/crypto/krb/crypto_length.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/src/lib/crypto/krb/crypto_length.c b/src/lib/crypto/krb/crypto_length.c new file mode 100644 index 0000000..d99d18b --- /dev/null +++ b/src/lib/crypto/krb/crypto_length.c @@ -0,0 +1,170 @@ +/* + * lib/crypto/crypto_length.c + * + * Copyright 2008 by the Massachusetts Institute of Technology. + * All Rights Reserved. + * + * Export of this software from the United States of America may + * require a specific license from the United States Government. + * It is the responsibility of any person or organization contemplating + * export to obtain such a license before exporting. + * + * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and + * distribute this software and its documentation for any purpose and + * without fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright notice and + * this permission notice appear in supporting documentation, and that + * the name of M.I.T. not be used in advertising or publicity pertaining + * to distribution of the software without specific, written prior + * permission. Furthermore if you modify this software you must label + * your software as modified software and not distribute it in such a + * fashion that it might be confused with the original M.I.T. software. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" without express + * or implied warranty. + */ + +#include "k5-int.h" +#include "etypes.h" +#include "aead.h" + +krb5_error_code KRB5_CALLCONV +krb5_c_crypto_length(krb5_context context, + krb5_enctype enctype, + krb5_cryptotype type, + unsigned int *size) +{ + int i; + const struct krb5_keytypes *ktp = NULL; + krb5_error_code ret; + + for (i = 0; i < krb5_enctypes_length; i++) { + if (krb5_enctypes_list[i].etype == enctype) { + ktp = &krb5_enctypes_list[i]; + break; + } + } + + if (ktp == NULL || ktp->aead == NULL) { + return KRB5_BAD_ENCTYPE; + } + + switch (type) { + case KRB5_CRYPTO_TYPE_EMPTY: + case KRB5_CRYPTO_TYPE_SIGN_ONLY: + *size = 0; + ret = 0; + break; + case KRB5_CRYPTO_TYPE_DATA: + *size = (size_t)~0; /* match Heimdal */ + ret = 0; + break; + case KRB5_CRYPTO_TYPE_HEADER: + case KRB5_CRYPTO_TYPE_PADDING: + case KRB5_CRYPTO_TYPE_TRAILER: + case KRB5_CRYPTO_TYPE_CHECKSUM: + ret = ktp->aead->crypto_length(ktp->aead, ktp->enc, ktp->hash, type, size); + break; + default: + ret = EINVAL; + break; + } + + return ret; +} + +krb5_error_code KRB5_CALLCONV +krb5_c_padding_length(krb5_context context, + krb5_enctype enctype, + size_t data_length, + unsigned int *pad_length) +{ + int i; + const struct krb5_keytypes *ktp = NULL; + + for (i = 0; i < krb5_enctypes_length; i++) { + if (krb5_enctypes_list[i].etype == enctype) { + ktp = &krb5_enctypes_list[i]; + break; + } + } + + if (ktp == NULL || ktp->aead == NULL) { + return KRB5_BAD_ENCTYPE; + } + + return krb5int_c_padding_length(ktp->aead, ktp->enc, ktp->hash, data_length, pad_length); +} + +krb5_error_code KRB5_CALLCONV +krb5_c_crypto_length_iov(krb5_context context, + krb5_enctype enctype, + krb5_crypto_iov *data, + size_t num_data) +{ + krb5_error_code ret = 0; + size_t i; + const struct krb5_keytypes *ktp = NULL; + unsigned int data_length = 0, pad_length; + krb5_crypto_iov *padding = NULL; + + /* + * XXX need to rejig internal interface so we can accurately + * report variable header lengths + */ + + for (i = 0; i < (size_t)krb5_enctypes_length; i++) { + if (krb5_enctypes_list[i].etype == enctype) { + ktp = &krb5_enctypes_list[i]; + break; + } + } + + if (ktp == NULL || ktp->aead == NULL) { + return KRB5_BAD_ENCTYPE; + } + + for (i = 0; i < num_data; i++) { + krb5_crypto_iov *iov = &data[i]; + + switch (iov->flags) { + case KRB5_CRYPTO_TYPE_DATA: + data_length += iov->data.length; + break; + case KRB5_CRYPTO_TYPE_PADDING: + if (padding != NULL) + return EINVAL; + + padding = iov; + break; + case KRB5_CRYPTO_TYPE_HEADER: + case KRB5_CRYPTO_TYPE_TRAILER: + case KRB5_CRYPTO_TYPE_CHECKSUM: + ret = ktp->aead->crypto_length(ktp->aead, ktp->enc, ktp->hash, iov->flags, &iov->data.length); + break; + case KRB5_CRYPTO_TYPE_EMPTY: + case KRB5_CRYPTO_TYPE_SIGN_ONLY: + default: + break; + } + + if (ret != 0) + break; + } + + if (ret != 0) + return ret; + + ret = krb5int_c_padding_length(ktp->aead, ktp->enc, ktp->hash, data_length, &pad_length); + if (ret != 0) + return ret; + + if (pad_length != 0 && padding == NULL) + return EINVAL; + + if (padding != NULL) + padding->data.length = pad_length; + + return 0; +} + |