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Diffstat (limited to 'lib/gssapi/krb5/unwrap.c')
| -rw-r--r-- | lib/gssapi/krb5/unwrap.c | 413 |
1 files changed, 413 insertions, 0 deletions
diff --git a/lib/gssapi/krb5/unwrap.c b/lib/gssapi/krb5/unwrap.c new file mode 100644 index 000000000000..d0a33d86fbfc --- /dev/null +++ b/lib/gssapi/krb5/unwrap.c @@ -0,0 +1,413 @@ +/* + * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "krb5/gsskrb5_locl.h" + +RCSID("$Id: unwrap.c 19031 2006-11-13 18:02:57Z lha $"); + +static OM_uint32 +unwrap_des + (OM_uint32 * minor_status, + const gsskrb5_ctx context_handle, + const gss_buffer_t input_message_buffer, + gss_buffer_t output_message_buffer, + int * conf_state, + gss_qop_t * qop_state, + krb5_keyblock *key + ) +{ + u_char *p, *seq; + size_t len; + MD5_CTX md5; + u_char hash[16]; + DES_key_schedule schedule; + DES_cblock deskey; + DES_cblock zero; + int i; + uint32_t seq_number; + size_t padlength; + OM_uint32 ret; + int cstate; + int cmp; + + p = input_message_buffer->value; + ret = _gsskrb5_verify_header (&p, + input_message_buffer->length, + "\x02\x01", + GSS_KRB5_MECHANISM); + if (ret) + return ret; + + if (memcmp (p, "\x00\x00", 2) != 0) + return GSS_S_BAD_SIG; + p += 2; + if (memcmp (p, "\x00\x00", 2) == 0) { + cstate = 1; + } else if (memcmp (p, "\xFF\xFF", 2) == 0) { + cstate = 0; + } else + return GSS_S_BAD_MIC; + p += 2; + if(conf_state != NULL) + *conf_state = cstate; + if (memcmp (p, "\xff\xff", 2) != 0) + return GSS_S_DEFECTIVE_TOKEN; + p += 2; + p += 16; + + len = p - (u_char *)input_message_buffer->value; + + if(cstate) { + /* decrypt data */ + memcpy (&deskey, key->keyvalue.data, sizeof(deskey)); + + for (i = 0; i < sizeof(deskey); ++i) + deskey[i] ^= 0xf0; + DES_set_key (&deskey, &schedule); + memset (&zero, 0, sizeof(zero)); + DES_cbc_encrypt ((void *)p, + (void *)p, + input_message_buffer->length - len, + &schedule, + &zero, + DES_DECRYPT); + + memset (deskey, 0, sizeof(deskey)); + memset (&schedule, 0, sizeof(schedule)); + } + /* check pad */ + ret = _gssapi_verify_pad(input_message_buffer, + input_message_buffer->length - len, + &padlength); + if (ret) + return ret; + + MD5_Init (&md5); + MD5_Update (&md5, p - 24, 8); + MD5_Update (&md5, p, input_message_buffer->length - len); + MD5_Final (hash, &md5); + + memset (&zero, 0, sizeof(zero)); + memcpy (&deskey, key->keyvalue.data, sizeof(deskey)); + DES_set_key (&deskey, &schedule); + DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash), + &schedule, &zero); + if (memcmp (p - 8, hash, 8) != 0) + return GSS_S_BAD_MIC; + + /* verify sequence number */ + + HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex); + + p -= 16; + DES_set_key (&deskey, &schedule); + DES_cbc_encrypt ((void *)p, (void *)p, 8, + &schedule, (DES_cblock *)hash, DES_DECRYPT); + + memset (deskey, 0, sizeof(deskey)); + memset (&schedule, 0, sizeof(schedule)); + + seq = p; + _gsskrb5_decode_om_uint32(seq, &seq_number); + + if (context_handle->more_flags & LOCAL) + cmp = memcmp(&seq[4], "\xff\xff\xff\xff", 4); + else + cmp = memcmp(&seq[4], "\x00\x00\x00\x00", 4); + + if (cmp != 0) { + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + return GSS_S_BAD_MIC; + } + + ret = _gssapi_msg_order_check(context_handle->order, seq_number); + if (ret) { + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + return ret; + } + + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + + /* copy out data */ + + output_message_buffer->length = input_message_buffer->length + - len - padlength - 8; + output_message_buffer->value = malloc(output_message_buffer->length); + if(output_message_buffer->length != 0 && output_message_buffer->value == NULL) + return GSS_S_FAILURE; + memcpy (output_message_buffer->value, + p + 24, + output_message_buffer->length); + return GSS_S_COMPLETE; +} + +static OM_uint32 +unwrap_des3 + (OM_uint32 * minor_status, + const gsskrb5_ctx context_handle, + krb5_context context, + const gss_buffer_t input_message_buffer, + gss_buffer_t output_message_buffer, + int * conf_state, + gss_qop_t * qop_state, + krb5_keyblock *key + ) +{ + u_char *p; + size_t len; + u_char *seq; + krb5_data seq_data; + u_char cksum[20]; + uint32_t seq_number; + size_t padlength; + OM_uint32 ret; + int cstate; + krb5_crypto crypto; + Checksum csum; + int cmp; + + p = input_message_buffer->value; + ret = _gsskrb5_verify_header (&p, + input_message_buffer->length, + "\x02\x01", + GSS_KRB5_MECHANISM); + if (ret) + return ret; + + if (memcmp (p, "\x04\x00", 2) != 0) /* HMAC SHA1 DES3_KD */ + return GSS_S_BAD_SIG; + p += 2; + if (memcmp (p, "\x02\x00", 2) == 0) { + cstate = 1; + } else if (memcmp (p, "\xff\xff", 2) == 0) { + cstate = 0; + } else + return GSS_S_BAD_MIC; + p += 2; + if(conf_state != NULL) + *conf_state = cstate; + if (memcmp (p, "\xff\xff", 2) != 0) + return GSS_S_DEFECTIVE_TOKEN; + p += 2; + p += 28; + + len = p - (u_char *)input_message_buffer->value; + + if(cstate) { + /* decrypt data */ + krb5_data tmp; + + ret = krb5_crypto_init(context, key, + ETYPE_DES3_CBC_NONE, &crypto); + if (ret) { + *minor_status = ret; + return GSS_S_FAILURE; + } + ret = krb5_decrypt(context, crypto, KRB5_KU_USAGE_SEAL, + p, input_message_buffer->length - len, &tmp); + krb5_crypto_destroy(context, crypto); + if (ret) { + *minor_status = ret; + return GSS_S_FAILURE; + } + assert (tmp.length == input_message_buffer->length - len); + + memcpy (p, tmp.data, tmp.length); + krb5_data_free(&tmp); + } + /* check pad */ + ret = _gssapi_verify_pad(input_message_buffer, + input_message_buffer->length - len, + &padlength); + if (ret) + return ret; + + /* verify sequence number */ + + HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex); + + p -= 28; + + ret = krb5_crypto_init(context, key, + ETYPE_DES3_CBC_NONE, &crypto); + if (ret) { + *minor_status = ret; + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + return GSS_S_FAILURE; + } + { + DES_cblock ivec; + + memcpy(&ivec, p + 8, 8); + ret = krb5_decrypt_ivec (context, + crypto, + KRB5_KU_USAGE_SEQ, + p, 8, &seq_data, + &ivec); + } + krb5_crypto_destroy (context, crypto); + if (ret) { + *minor_status = ret; + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + return GSS_S_FAILURE; + } + if (seq_data.length != 8) { + krb5_data_free (&seq_data); + *minor_status = 0; + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + return GSS_S_BAD_MIC; + } + + seq = seq_data.data; + _gsskrb5_decode_om_uint32(seq, &seq_number); + + if (context_handle->more_flags & LOCAL) + cmp = memcmp(&seq[4], "\xff\xff\xff\xff", 4); + else + cmp = memcmp(&seq[4], "\x00\x00\x00\x00", 4); + + krb5_data_free (&seq_data); + if (cmp != 0) { + *minor_status = 0; + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + return GSS_S_BAD_MIC; + } + + ret = _gssapi_msg_order_check(context_handle->order, seq_number); + if (ret) { + *minor_status = 0; + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + return ret; + } + + HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); + + /* verify checksum */ + + memcpy (cksum, p + 8, 20); + + memcpy (p + 20, p - 8, 8); + + csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3; + csum.checksum.length = 20; + csum.checksum.data = cksum; + + ret = krb5_crypto_init(context, key, 0, &crypto); + if (ret) { + *minor_status = ret; + return GSS_S_FAILURE; + } + + ret = krb5_verify_checksum (context, crypto, + KRB5_KU_USAGE_SIGN, + p + 20, + input_message_buffer->length - len + 8, + &csum); + krb5_crypto_destroy (context, crypto); + if (ret) { + *minor_status = ret; + return GSS_S_FAILURE; + } + + /* copy out data */ + + output_message_buffer->length = input_message_buffer->length + - len - padlength - 8; + output_message_buffer->value = malloc(output_message_buffer->length); + if(output_message_buffer->length != 0 && output_message_buffer->value == NULL) + return GSS_S_FAILURE; + memcpy (output_message_buffer->value, + p + 36, + output_message_buffer->length); + return GSS_S_COMPLETE; +} + +OM_uint32 _gsskrb5_unwrap + (OM_uint32 * minor_status, + const gss_ctx_id_t context_handle, + const gss_buffer_t input_message_buffer, + gss_buffer_t output_message_buffer, + int * conf_state, + gss_qop_t * qop_state + ) +{ + krb5_keyblock *key; + krb5_context context; + OM_uint32 ret; + krb5_keytype keytype; + gsskrb5_ctx ctx = (gsskrb5_ctx) context_handle; + + output_message_buffer->value = NULL; + output_message_buffer->length = 0; + + GSSAPI_KRB5_INIT (&context); + + if (qop_state != NULL) + *qop_state = GSS_C_QOP_DEFAULT; + HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex); + ret = _gsskrb5i_get_token_key(ctx, context, &key); + HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex); + if (ret) { + *minor_status = ret; + return GSS_S_FAILURE; + } + krb5_enctype_to_keytype (context, key->keytype, &keytype); + + *minor_status = 0; + + switch (keytype) { + case KEYTYPE_DES : + ret = unwrap_des (minor_status, ctx, + input_message_buffer, output_message_buffer, + conf_state, qop_state, key); + break; + case KEYTYPE_DES3 : + ret = unwrap_des3 (minor_status, ctx, context, + input_message_buffer, output_message_buffer, + conf_state, qop_state, key); + break; + case KEYTYPE_ARCFOUR: + case KEYTYPE_ARCFOUR_56: + ret = _gssapi_unwrap_arcfour (minor_status, ctx, context, + input_message_buffer, output_message_buffer, + conf_state, qop_state, key); + break; + default : + ret = _gssapi_unwrap_cfx (minor_status, ctx, context, + input_message_buffer, output_message_buffer, + conf_state, qop_state, key); + break; + } + krb5_free_keyblock (context, key); + return ret; +} |