diff options
Diffstat (limited to 'src/lib/crypto/krb/raw/raw_aead.c')
| -rw-r--r-- | src/lib/crypto/krb/raw/raw_aead.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/src/lib/crypto/krb/raw/raw_aead.c b/src/lib/crypto/krb/raw/raw_aead.c new file mode 100644 index 0000000..f52fe00 --- /dev/null +++ b/src/lib/crypto/krb/raw/raw_aead.c @@ -0,0 +1,163 @@ +/* + * lib/crypto/raw/raw_aead.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 "raw.h" +#include "aead.h" + +/* AEAD */ + +static krb5_error_code +krb5int_raw_crypto_length(const struct krb5_aead_provider *aead, + const struct krb5_enc_provider *enc, + const struct krb5_hash_provider *hash, + krb5_cryptotype type, + unsigned int *length) +{ + switch (type) { + case KRB5_CRYPTO_TYPE_PADDING: + *length = enc->block_size; + break; + default: + *length = 0; + break; + } + + return 0; +} + +static krb5_error_code +krb5int_raw_encrypt_iov(const struct krb5_aead_provider *aead, + const struct krb5_enc_provider *enc, + const struct krb5_hash_provider *hash, + const krb5_keyblock *key, + krb5_keyusage usage, + const krb5_data *ivec, + krb5_crypto_iov *data, + size_t num_data) +{ + krb5_error_code ret; + krb5_crypto_iov *padding; + size_t i; + unsigned int blocksize = 0; + unsigned int plainlen = 0; + unsigned int padsize = 0; + + ret = aead->crypto_length(aead, enc, hash, KRB5_CRYPTO_TYPE_PADDING, &blocksize); + if (ret != 0) + return ret; + + for (i = 0; i < num_data; i++) { + krb5_crypto_iov *iov = &data[i]; + + if (iov->flags == KRB5_CRYPTO_TYPE_DATA) + plainlen += iov->data.length; + } + + if (blocksize != 0) { + /* Check that the input data is correctly padded */ + if (plainlen % blocksize) + padsize = blocksize - (plainlen % blocksize); + } + + padding = krb5int_c_locate_iov(data, num_data, KRB5_CRYPTO_TYPE_PADDING); + if (padsize && (padding == NULL || padding->data.length < padsize)) + return KRB5_BAD_MSIZE; + + if (padding != NULL) { + memset(padding->data.data, 0, padsize); + padding->data.length = padsize; + } + + assert(enc->encrypt_iov != NULL); + + ret = enc->encrypt_iov(key, ivec, data, num_data); /* will update ivec */ + + return ret; +} + +static krb5_error_code +krb5int_raw_decrypt_iov(const struct krb5_aead_provider *aead, + const struct krb5_enc_provider *enc, + const struct krb5_hash_provider *hash, + const krb5_keyblock *key, + krb5_keyusage usage, + const krb5_data *ivec, + krb5_crypto_iov *data, + size_t num_data) +{ + krb5_error_code ret; + size_t i; + unsigned int blocksize = 0; /* careful, this is enc block size not confounder len */ + unsigned int cipherlen = 0; + + if (krb5int_c_locate_iov(data, num_data, KRB5_CRYPTO_TYPE_STREAM) != NULL) { + return krb5int_c_iov_decrypt_stream(aead, enc, hash, key, + usage, ivec, data, num_data); + } + + + /* E(Confounder | Plaintext | Pad) | Checksum */ + + ret = aead->crypto_length(aead, enc, hash, KRB5_CRYPTO_TYPE_PADDING, &blocksize); + if (ret != 0) + return ret; + + for (i = 0; i < num_data; i++) { + const krb5_crypto_iov *iov = &data[i]; + + if (ENCRYPT_DATA_IOV(iov)) + cipherlen += iov->data.length; + } + + if (blocksize == 0) { + /* Check for correct input length in CTS mode */ + if (enc->block_size != 0 && cipherlen < enc->block_size) + return KRB5_BAD_MSIZE; + } else { + /* Check that the input data is correctly padded */ + if ((cipherlen % blocksize) != 0) + return KRB5_BAD_MSIZE; + } + + /* Validate header and trailer lengths */ + + /* derive the keys */ + + /* decrypt the plaintext (header | data | padding) */ + assert(enc->decrypt_iov != NULL); + + ret = enc->decrypt_iov(key, ivec, data, num_data); /* will update ivec */ + + return ret; +} + +const struct krb5_aead_provider krb5int_aead_raw = { + krb5int_raw_crypto_length, + krb5int_raw_encrypt_iov, + krb5int_raw_decrypt_iov +}; |