Exemplo n.º 1
0
static void
test_enctype(krb5_enctype enctype)
{
    krb5_error_code ret;
    krb5_keyblock keyblock;
    krb5_enc_data input;
    krb5_data output;
    krb5_crypto_iov iov[2];
    unsigned int dummy;
    size_t min_len, len;

    printf("Testing enctype %d\n", (int) enctype);
    x(krb5_c_encrypt_length(NULL, enctype, 0, &min_len));
    x(krb5_c_make_random_key(NULL, enctype, &keyblock));
    input.enctype = enctype;

    /* Try each length up to the minimum length. */
    for (len = 0; len <= min_len; len++) {
        input.ciphertext.data = calloc(len, 1);
        input.ciphertext.length = len;
        output.data = calloc(len, 1);
        output.length = len;

        /* Attempt a normal decryption. */
        ret = krb5_c_decrypt(NULL, &keyblock, 0, NULL, &input, &output);
        check_decrypt_result(ret, len, min_len);

        if (krb5_c_crypto_length(NULL, enctype, KRB5_CRYPTO_TYPE_HEADER,
                                 &dummy) == 0) {
            /* Attempt an IOV stream decryption. */
            iov[0].flags = KRB5_CRYPTO_TYPE_STREAM;
            iov[0].data = input.ciphertext;
            iov[1].flags = KRB5_CRYPTO_TYPE_DATA;
            iov[1].data.data = NULL;
            iov[1].data.length = 0;
            ret = krb5_c_decrypt_iov(NULL, &keyblock, 0, NULL, iov, 2);
            check_decrypt_result(ret, len, min_len);
        }

        free(input.ciphertext.data);
        free(output.data);
    }
    krb5int_c_free_keyblock_contents (NULL, &keyblock);

}
Exemplo n.º 2
0
OM_uint32
kg_seal_iov_length(OM_uint32 *minor_status,
                   gss_ctx_id_t context_handle,
                   int conf_req_flag,
                   gss_qop_t qop_req,
                   int *conf_state,
                   gss_iov_buffer_desc *iov,
                   int iov_count)
{
    krb5_gss_ctx_id_rec *ctx;
    gss_iov_buffer_t header, trailer, padding;
    size_t data_length, assoc_data_length;
    size_t gss_headerlen, gss_padlen, gss_trailerlen;
    unsigned int k5_headerlen = 0, k5_trailerlen = 0, k5_padlen = 0;
    krb5_error_code code;
    krb5_context context;
    int dce_style;

    if (qop_req != GSS_C_QOP_DEFAULT) {
        *minor_status = (OM_uint32)G_UNKNOWN_QOP;
        return GSS_S_FAILURE;
    }

    if (!kg_validate_ctx_id(context_handle)) {
        *minor_status = (OM_uint32)G_VALIDATE_FAILED;
        return GSS_S_NO_CONTEXT;
    }

    ctx = (krb5_gss_ctx_id_rec *)context_handle;
    if (!ctx->established) {
        *minor_status = KG_CTX_INCOMPLETE;
        return GSS_S_NO_CONTEXT;
    }

    header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
    if (header == NULL) {
        *minor_status = EINVAL;
        return GSS_S_FAILURE;
    }
    INIT_IOV_DATA(header);

    trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
    if (trailer != NULL) {
        INIT_IOV_DATA(trailer);
    }

    dce_style = ((ctx->gss_flags & GSS_C_DCE_STYLE) != 0);

    /* For CFX, EC is used instead of padding, and is placed in header or trailer */
    padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
    if (padding == NULL) {
        if (conf_req_flag && ctx->proto == 0 && !dce_style) {
            *minor_status = EINVAL;
            return GSS_S_FAILURE;
        }
    } else {
        INIT_IOV_DATA(padding);
    }

    kg_iov_msglen(iov, iov_count, &data_length, &assoc_data_length);

    if (conf_req_flag && kg_integ_only_iov(iov, iov_count))
        conf_req_flag = FALSE;

    context = ctx->k5_context;

    gss_headerlen = gss_padlen = gss_trailerlen = 0;

    if (ctx->proto == 1) {
        krb5_enctype enctype;
        size_t ec;

        if (ctx->have_acceptor_subkey)
            enctype = ctx->acceptor_subkey->enctype;
        else
            enctype = ctx->subkey->enctype;

        code = krb5_c_crypto_length(context, enctype,
                                    conf_req_flag ?
                                        KRB5_CRYPTO_TYPE_TRAILER : KRB5_CRYPTO_TYPE_CHECKSUM,
                                    &k5_trailerlen);
        if (code != 0) {
            *minor_status = code;
            return GSS_S_FAILURE;
        }

        if (conf_req_flag) {
            code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
            if (code != 0) {
                *minor_status = code;
                return GSS_S_FAILURE;
            }
        }

        gss_headerlen = 16; /* Header */
        if (conf_req_flag) {
            gss_headerlen += k5_headerlen; /* Kerb-Header */
            gss_trailerlen = 16 /* E(Header) */ + k5_trailerlen; /* Kerb-Trailer */

            code = krb5_c_padding_length(context, enctype,
                                         data_length - assoc_data_length + 16 /* E(Header) */, &k5_padlen);
            if (code != 0) {
                *minor_status = code;
                return GSS_S_FAILURE;
            }

            if (k5_padlen == 0 && dce_style) {
                /* Windows rejects AEAD tokens with non-zero EC */
                code = krb5_c_block_size(context, enctype, &ec);
                if (code != 0) {
                    *minor_status = code;
                    return GSS_S_FAILURE;
                }
            } else
                ec = k5_padlen;

            gss_trailerlen += ec;
        } else {
            gss_trailerlen = k5_trailerlen; /* Kerb-Checksum */
        }
    } else if (!dce_style) {
        k5_padlen = (ctx->sealalg == SEAL_ALG_MICROSOFT_RC4) ? 1 : 8;

        if (k5_padlen == 1)
            gss_padlen = 1;
        else
            gss_padlen = k5_padlen - ((data_length - assoc_data_length) % k5_padlen);
    }

    data_length += gss_padlen;

    if (ctx->proto == 0) {
        /* Header | Checksum | Confounder | Data | Pad */
        size_t data_size;

        k5_headerlen = kg_confounder_size(context, ctx->enc);

        data_size = 14 /* Header */ + ctx->cksum_size + k5_headerlen;

        if (!dce_style)
            data_size += data_length;

        gss_headerlen = g_token_size(ctx->mech_used, data_size);

        /* g_token_size() will include data_size as well as the overhead, so
         * subtract data_length just to get the overhead (ie. token size) */
        if (!dce_style)
            gss_headerlen -= data_length;
    }

    if (minor_status != NULL)
        *minor_status = 0;

    if (trailer == NULL)
        gss_headerlen += gss_trailerlen;
    else
        trailer->buffer.length = gss_trailerlen;

    assert(gss_padlen == 0 || padding != NULL);

    if (padding != NULL)
        padding->buffer.length = gss_padlen;

    header->buffer.length = gss_headerlen;

    if (conf_state != NULL)
        *conf_state = conf_req_flag;

    return GSS_S_COMPLETE;
}
Exemplo n.º 3
0
/*
 * Split a STREAM | SIGN_DATA | DATA into
 *         HEADER | SIGN_DATA | DATA | PADDING | TRAILER
 */
static OM_uint32
kg_unseal_stream_iov(OM_uint32 *minor_status,
                     krb5_gss_ctx_id_rec *ctx,
                     int *conf_state,
                     gss_qop_t *qop_state,
                     gss_iov_buffer_desc *iov,
                     int iov_count,
                     int toktype)
{
    unsigned char *ptr;
    unsigned int bodysize;
    OM_uint32 code = 0, major_status = GSS_S_FAILURE;
    krb5_context context = ctx->k5_context;
    int conf_req_flag, toktype2;
    int i = 0, j;
    gss_iov_buffer_desc *tiov = NULL;
    gss_iov_buffer_t stream, data = NULL;
    gss_iov_buffer_t theader, tdata = NULL, tpadding, ttrailer;

    assert(toktype == KG_TOK_WRAP_MSG);

    if (toktype != KG_TOK_WRAP_MSG || (ctx->gss_flags & GSS_C_DCE_STYLE)) {
        code = EINVAL;
        goto cleanup;
    }

    stream = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_STREAM);
    assert(stream != NULL);

    ptr = (unsigned char *)stream->buffer.value;

    code = g_verify_token_header(ctx->mech_used,
                                 &bodysize, &ptr, -1,
                                 stream->buffer.length, 0);
    if (code != 0) {
        major_status = GSS_S_DEFECTIVE_TOKEN;
        goto cleanup;
    }

    if (bodysize < 2) {
        *minor_status = (OM_uint32)G_BAD_TOK_HEADER;
        return GSS_S_DEFECTIVE_TOKEN;
    }

    toktype2 = load_16_be(ptr);

    ptr += 2;
    bodysize -= 2;

    tiov = (gss_iov_buffer_desc *)calloc((size_t)iov_count + 2, sizeof(gss_iov_buffer_desc));
    if (tiov == NULL) {
        code = ENOMEM;
        goto cleanup;
    }

    /* HEADER */
    theader = &tiov[i++];
    theader->type = GSS_IOV_BUFFER_TYPE_HEADER;
    theader->buffer.value = stream->buffer.value;
    theader->buffer.length = ptr - (unsigned char *)stream->buffer.value;
    if (bodysize < 14 ||
        stream->buffer.length != theader->buffer.length + bodysize) {
        major_status = GSS_S_DEFECTIVE_TOKEN;
        goto cleanup;
    }
    theader->buffer.length += 14;

    /* n[SIGN_DATA] | DATA | m[SIGN_DATA] */
    for (j = 0; j < iov_count; j++) {
        OM_uint32 type = GSS_IOV_BUFFER_TYPE(iov[j].type);

        if (type == GSS_IOV_BUFFER_TYPE_DATA) {
            if (data != NULL) {
                /* only a single DATA buffer can appear */
                code = EINVAL;
                goto cleanup;
            }

            data = &iov[j];
            tdata = &tiov[i];
        }
        if (type == GSS_IOV_BUFFER_TYPE_DATA ||
            type == GSS_IOV_BUFFER_TYPE_SIGN_ONLY)
            tiov[i++] = iov[j];
    }

    if (data == NULL) {
        /* a single DATA buffer must be present */
        code = EINVAL;
        goto cleanup;
    }

    /* PADDING | TRAILER */
    tpadding = &tiov[i++];
    tpadding->type = GSS_IOV_BUFFER_TYPE_PADDING;
    tpadding->buffer.length = 0;
    tpadding->buffer.value = NULL;

    ttrailer = &tiov[i++];
    ttrailer->type = GSS_IOV_BUFFER_TYPE_TRAILER;

    switch (toktype2) {
    case KG2_TOK_MIC_MSG:
    case KG2_TOK_WRAP_MSG:
    case KG2_TOK_DEL_CTX: {
        size_t ec, rrc;
        krb5_enctype enctype;
        unsigned int k5_headerlen = 0;
        unsigned int k5_trailerlen = 0;

        if (ctx->have_acceptor_subkey)
            enctype = ctx->acceptor_subkey->keyblock.enctype;
        else
            enctype = ctx->subkey->keyblock.enctype;
        conf_req_flag = ((ptr[0] & FLAG_WRAP_CONFIDENTIAL) != 0);
        ec = conf_req_flag ? load_16_be(ptr + 2) : 0;
        rrc = load_16_be(ptr + 4);

        if (rrc != 0) {
            if (!gss_krb5int_rotate_left((unsigned char *)stream->buffer.value + 16,
                                         stream->buffer.length - 16, rrc)) {
                code = ENOMEM;
                goto cleanup;
            }
            store_16_be(0, ptr + 4); /* set RRC to zero */
        }

        if (conf_req_flag) {
            code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
            if (code != 0)
                goto cleanup;
            theader->buffer.length += k5_headerlen; /* length validated later */
        }

        /* no PADDING for CFX, EC is used instead */
        code = krb5_c_crypto_length(context, enctype,
                                    conf_req_flag ? KRB5_CRYPTO_TYPE_TRAILER : KRB5_CRYPTO_TYPE_CHECKSUM,
                                    &k5_trailerlen);
        if (code != 0)
            goto cleanup;

        ttrailer->buffer.length = ec + (conf_req_flag ? 16 : 0 /* E(Header) */) + k5_trailerlen;
        ttrailer->buffer.value = (unsigned char *)stream->buffer.value +
            stream->buffer.length - ttrailer->buffer.length;
        break;
    }
    case KG_TOK_MIC_MSG:
    case KG_TOK_WRAP_MSG:
    case KG_TOK_DEL_CTX:
        theader->buffer.length += ctx->cksum_size +
            kg_confounder_size(context, ctx->enc->keyblock.enctype);

        /*
         * we can't set the padding accurately until decryption;
         * kg_fixup_padding_iov() will take care of this
         */
        tpadding->buffer.length = 1;
        tpadding->buffer.value = (unsigned char *)stream->buffer.value + stream->buffer.length - 1;

        /* no TRAILER for pre-CFX */
        ttrailer->buffer.length = 0;
        ttrailer->buffer.value = NULL;

        break;
    default:
        code = (OM_uint32)G_BAD_TOK_HEADER;
        major_status = GSS_S_DEFECTIVE_TOKEN;
        goto cleanup;
        break;
    }

    /* IOV: -----------0-------------+---1---+--2--+----------------3--------------*/
    /* Old: GSS-Header | Conf        | Data  | Pad |                               */
    /* CFX: GSS-Header | Kerb-Header | Data  |     | EC | E(Header) | Kerb-Trailer */
    /* GSS: -------GSS-HEADER--------+-DATA--+-PAD-+----------GSS-TRAILER----------*/

    /* validate lengths */
    if (stream->buffer.length < theader->buffer.length +
        tpadding->buffer.length +
        ttrailer->buffer.length)
    {
        code = (OM_uint32)KRB5_BAD_MSIZE;
        major_status = GSS_S_DEFECTIVE_TOKEN;
        goto cleanup;
    }

    /* setup data */
    tdata->buffer.length = stream->buffer.length - ttrailer->buffer.length -
        tpadding->buffer.length - theader->buffer.length;

    assert(data != NULL);

    if (data->type & GSS_IOV_BUFFER_FLAG_ALLOCATE) {
        code = kg_allocate_iov(tdata, tdata->buffer.length);
        if (code != 0)
            goto cleanup;
        memcpy(tdata->buffer.value,
               (unsigned char *)stream->buffer.value + theader->buffer.length, tdata->buffer.length);
    } else
        tdata->buffer.value = (unsigned char *)stream->buffer.value + theader->buffer.length;

    assert(i <= iov_count + 2);

    major_status = kg_unseal_iov_token(&code, ctx, conf_state, qop_state,
                                       tiov, i, toktype);
    if (major_status == GSS_S_COMPLETE)
        *data = *tdata;
    else
        kg_release_iov(tdata, 1);

cleanup:
    if (tiov != NULL)
        free(tiov);

    *minor_status = code;

    return major_status;
}
Exemplo n.º 4
0
int
main ()
{
    krb5_context context = 0;
    krb5_data  in, in2, out, out2, check, check2, state, signdata;
    krb5_crypto_iov iov[5];
    int i, j, pos;
    unsigned int dummy;
    size_t len;
    krb5_enc_data enc_out, enc_out2;
    krb5_keyblock *keyblock;
    krb5_key key;

    memset(iov, 0, sizeof(iov));

    in.data = "This is a test.\n";
    in.length = strlen (in.data);
    in2.data = "This is another test.\n";
    in2.length = strlen (in2.data);

    test ("Seeding random number generator",
          krb5_c_random_seed (context, &in));

    /* Set up output buffers. */
    out.data = malloc(2048);
    out2.data = malloc(2048);
    check.data = malloc(2048);
    check2.data = malloc(2048);
    if (out.data == NULL || out2.data == NULL
        || check.data == NULL || check2.data == NULL)
        abort();
    out.magic = KV5M_DATA;
    out.length = 2048;
    out2.magic = KV5M_DATA;
    out2.length = 2048;
    check.length = 2048;
    check2.length = 2048;

    for (i = 0; interesting_enctypes[i]; i++) {
        krb5_enctype enctype = interesting_enctypes [i];

        printf ("Testing enctype %d\n", enctype);
        test ("Initializing a keyblock",
              krb5_init_keyblock (context, enctype, 0, &keyblock));
        test ("Generating random keyblock",
              krb5_c_make_random_key (context, enctype, keyblock));
        test ("Creating opaque key from keyblock",
              krb5_k_create_key (context, keyblock, &key));

        enc_out.ciphertext = out;
        enc_out2.ciphertext = out2;
        /* We use an intermediate `len' because size_t may be different size
           than `int' */
        krb5_c_encrypt_length (context, keyblock->enctype, in.length, &len);
        enc_out.ciphertext.length = len;

        /* Encrypt, decrypt, and see if we got the plaintext back again. */
        test ("Encrypting (c)",
              krb5_c_encrypt (context, keyblock, 7, 0, &in, &enc_out));
        display ("Enc output", &enc_out.ciphertext);
        test ("Decrypting",
              krb5_c_decrypt (context, keyblock, 7, 0, &enc_out, &check));
        test ("Comparing", compare_results (&in, &check));

        /* Try again with the opaque-key-using variants. */
        memset(out.data, 0, out.length);
        test ("Encrypting (k)",
              krb5_k_encrypt (context, key, 7, 0, &in, &enc_out));
        display ("Enc output", &enc_out.ciphertext);
        test ("Decrypting",
              krb5_k_decrypt (context, key, 7, 0, &enc_out, &check));
        test ("Comparing", compare_results (&in, &check));

        /* Check if this enctype supports IOV encryption. */
        if ( krb5_c_crypto_length(context, keyblock->enctype,
                                  KRB5_CRYPTO_TYPE_HEADER, &dummy) == 0 ){
            /* Set up iovecs for stream decryption. */
            memcpy(out2.data, enc_out.ciphertext.data, enc_out.ciphertext.length);
            iov[0].flags= KRB5_CRYPTO_TYPE_STREAM;
            iov[0].data.data = out2.data;
            iov[0].data.length = enc_out.ciphertext.length;
            iov[1].flags = KRB5_CRYPTO_TYPE_DATA;

            /* Decrypt the encrypted data from above and check it. */
            test("IOV stream decrypting (c)",
                 krb5_c_decrypt_iov( context, keyblock, 7, 0, iov, 2));
            test("Comparing results",
                 compare_results(&in, &iov[1].data));

            /* Try again with the opaque-key-using variant. */
            memcpy(out2.data, enc_out.ciphertext.data, enc_out.ciphertext.length);
            test("IOV stream decrypting (k)",
                 krb5_k_decrypt_iov( context, key, 7, 0, iov, 2));
            test("Comparing results",
                 compare_results(&in, &iov[1].data));

            /* Set up iovecs for AEAD encryption. */
            signdata.magic = KV5M_DATA;
            signdata.data = (char *) "This should be signed";
            signdata.length = strlen(signdata.data);
            iov[0].flags = KRB5_CRYPTO_TYPE_HEADER;
            iov[1].flags = KRB5_CRYPTO_TYPE_DATA;
            iov[1].data = in; /*We'll need to copy memory before encrypt*/
            iov[2].flags = KRB5_CRYPTO_TYPE_SIGN_ONLY;
            iov[2].data = signdata;
            iov[3].flags = KRB5_CRYPTO_TYPE_PADDING;
            iov[4].flags = KRB5_CRYPTO_TYPE_TRAILER;

            /* "Allocate" data for the iovec buffers from the "out" buffer. */
            test("Setting up iov lengths",
                 krb5_c_crypto_length_iov(context, keyblock->enctype, iov, 5));
            for (j=0,pos=0; j <= 4; j++ ){
                if (iov[j].flags == KRB5_CRYPTO_TYPE_SIGN_ONLY)
                    continue;
                iov[j].data.data = &out.data[pos];
                pos += iov[j].data.length;
            }
            assert (iov[1].data.length == in.length);
            memcpy(iov[1].data.data, in.data, in.length);

            /* Encrypt and decrypt in place, and check the result. */
            test("iov encrypting (c)",
                 krb5_c_encrypt_iov(context, keyblock, 7, 0, iov, 5));
            assert(iov[1].data.length == in.length);
            display("Header", &iov[0].data);
            display("Data", &iov[1].data);
            display("Padding", &iov[3].data);
            display("Trailer", &iov[4].data);
            test("iov decrypting",
                 krb5_c_decrypt_iov(context, keyblock, 7, 0, iov, 5));
            test("Comparing results",
                 compare_results(&in, &iov[1].data));

            /* Try again with opaque-key-using variants. */
            test("iov encrypting (k)",
                 krb5_k_encrypt_iov(context, key, 7, 0, iov, 5));
            assert(iov[1].data.length == in.length);
            display("Header", &iov[0].data);
            display("Data", &iov[1].data);
            display("Padding", &iov[3].data);
            display("Trailer", &iov[4].data);
            test("iov decrypting",
                 krb5_k_decrypt_iov(context, key, 7, 0, iov, 5));
            test("Comparing results",
                 compare_results(&in, &iov[1].data));
        }

        enc_out.ciphertext.length = out.length;
        check.length = 2048;

        test ("init_state",
              krb5_c_init_state (context, keyblock, 7, &state));
        test ("Encrypting with state",
              krb5_c_encrypt (context, keyblock, 7, &state, &in, &enc_out));
        display ("Enc output", &enc_out.ciphertext);
        test ("Encrypting again with state",
              krb5_c_encrypt (context, keyblock, 7, &state, &in2, &enc_out2));
        display ("Enc output", &enc_out2.ciphertext);
        test ("free_state",
              krb5_c_free_state (context, keyblock, &state));
        test ("init_state",
              krb5_c_init_state (context, keyblock, 7, &state));
        test ("Decrypting with state",
              krb5_c_decrypt (context, keyblock, 7, &state, &enc_out, &check));
        test ("Decrypting again with state",
              krb5_c_decrypt (context, keyblock, 7, &state, &enc_out2, &check2));
        test ("free_state",
              krb5_c_free_state (context, keyblock, &state));
        test ("Comparing",
              compare_results (&in, &check));
        test ("Comparing",
              compare_results (&in2, &check2));

        krb5_free_keyblock (context, keyblock);
        krb5_k_free_key (context, key);
    }

    /* Test the RC4 decrypt fallback from key usage 9 to 8. */
    test ("Initializing an RC4 keyblock",
          krb5_init_keyblock (context, ENCTYPE_ARCFOUR_HMAC, 0, &keyblock));
    test ("Generating random RC4 key",
          krb5_c_make_random_key (context, ENCTYPE_ARCFOUR_HMAC, keyblock));
    enc_out.ciphertext = out;
    krb5_c_encrypt_length (context, keyblock->enctype, in.length, &len);
    enc_out.ciphertext.length = len;
    check.length = 2048;
    test ("Encrypting with RC4 key usage 8",
          krb5_c_encrypt (context, keyblock, 8, 0, &in, &enc_out));
    display ("Enc output", &enc_out.ciphertext);
    test ("Decrypting with RC4 key usage 9",
          krb5_c_decrypt (context, keyblock, 9, 0, &enc_out, &check));
    test ("Comparing", compare_results (&in, &check));

    krb5_free_keyblock (context, keyblock);
    free(out.data);
    free(out2.data);
    free(check.data);
    free(check2.data);
    return 0;
}
Exemplo n.º 5
0
/*
 * DCE_STYLE indicates actual RRC is EC + RRC
 * EC is extra rotate count for DCE_STYLE, pad length otherwise
 * RRC is rotate count.
 */
static krb5_error_code
kg_translate_iov_v3(krb5_context context, int dce_style, size_t ec, size_t rrc,
                    krb5_enctype enctype, gss_iov_buffer_desc *iov,
                    int iov_count, krb5_crypto_iov **pkiov,
                    size_t *pkiov_count)
{
    gss_iov_buffer_t header;
    gss_iov_buffer_t trailer;
    int i = 0, j;
    size_t kiov_count;
    krb5_crypto_iov *kiov;
    unsigned int k5_headerlen = 0, k5_trailerlen = 0;
    size_t gss_headerlen, gss_trailerlen;
    krb5_error_code code;

    *pkiov = NULL;
    *pkiov_count = 0;

    header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
    assert(header != NULL);

    trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
    assert(trailer == NULL || rrc == 0);

    code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_HEADER,
                                &k5_headerlen);
    if (code != 0)
        return code;

    code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_TRAILER,
                                &k5_trailerlen);
    if (code != 0)
        return code;

    /* Check header and trailer sizes */
    gss_headerlen = 16 /* GSS-Header */ + k5_headerlen; /* Kerb-Header */
    gss_trailerlen = ec + 16 /* E(GSS-Header) */ + k5_trailerlen; /* Kerb-Trailer */

    /* If we're caller without a trailer, we must rotate by trailer length */
    if (trailer == NULL) {
        size_t actual_rrc = rrc;

        if (dce_style)
            actual_rrc += ec; /* compensate for Windows bug */

        if (actual_rrc != gss_trailerlen)
            return KRB5_BAD_MSIZE;

        gss_headerlen += gss_trailerlen;
        gss_trailerlen = 0;
    } else {
        if (trailer->buffer.length != gss_trailerlen)
            return KRB5_BAD_MSIZE;
    }

    if (header->buffer.length != gss_headerlen)
        return KRB5_BAD_MSIZE;

    kiov_count = 3 + iov_count;
    kiov = (krb5_crypto_iov *)malloc(kiov_count * sizeof(krb5_crypto_iov));
    if (kiov == NULL)
        return ENOMEM;

    /*
     * The krb5 header is located at the end of the GSS header.
     */
    kiov[i].flags = KRB5_CRYPTO_TYPE_HEADER;
    kiov[i].data.length = k5_headerlen;
    kiov[i].data.data = (char *)header->buffer.value + header->buffer.length - k5_headerlen;
    i++;

    for (j = 0; j < iov_count; j++) {
        kiov[i].flags = kg_translate_flag_iov(iov[j].type);
        if (kiov[i].flags == KRB5_CRYPTO_TYPE_EMPTY)
            continue;

        kiov[i].data.length = iov[j].buffer.length;
        kiov[i].data.data = (char *)iov[j].buffer.value;
        i++;
    }

    /*
     * The EC and encrypted GSS header are placed in the trailer, which may
     * be rotated directly after the plaintext header if no trailer buffer
     * is provided.
     */
    kiov[i].flags = KRB5_CRYPTO_TYPE_DATA;
    kiov[i].data.length = ec + 16; /* E(Header) */
    if (trailer == NULL)
        kiov[i].data.data = (char *)header->buffer.value + 16;
    else
        kiov[i].data.data = (char *)trailer->buffer.value;
    i++;

    /*
     * The krb5 trailer is placed after the encrypted copy of the
     * krb5 header (which may be in the GSS header or trailer).
     */
    kiov[i].flags = KRB5_CRYPTO_TYPE_TRAILER;
    kiov[i].data.length = k5_trailerlen;
    kiov[i].data.data = kiov[i - 1].data.data + ec + 16; /* E(Header) */
    i++;

    *pkiov = kiov;
    *pkiov_count = i;

    return 0;
}
Exemplo n.º 6
0
krb5_error_code
gss_krb5int_make_seal_token_v3_iov(krb5_context context,
                                   krb5_gss_ctx_id_rec *ctx,
                                   int conf_req_flag,
                                   int *conf_state,
                                   gss_iov_buffer_desc *iov,
                                   int iov_count,
                                   int toktype)
{
    krb5_error_code code = 0;
    gss_iov_buffer_t header;
    gss_iov_buffer_t padding;
    gss_iov_buffer_t trailer;
    unsigned char acceptor_flag;
    unsigned short tok_id;
    unsigned char *outbuf = NULL;
    unsigned char *tbuf = NULL;
    int key_usage;
    size_t rrc = 0;
    unsigned int  gss_headerlen, gss_trailerlen;
    krb5_key key;
    krb5_cksumtype cksumtype;
    size_t data_length, assoc_data_length;

    assert(ctx->big_endian == 0);
    assert(ctx->proto == 1);

    acceptor_flag = ctx->initiate ? 0 : FLAG_SENDER_IS_ACCEPTOR;
    key_usage = (toktype == KG_TOK_WRAP_MSG
                 ? (ctx->initiate
                    ? KG_USAGE_INITIATOR_SEAL
                    : KG_USAGE_ACCEPTOR_SEAL)
                 : (ctx->initiate
                    ? KG_USAGE_INITIATOR_SIGN
                    : KG_USAGE_ACCEPTOR_SIGN));
    if (ctx->have_acceptor_subkey) {
        key = ctx->acceptor_subkey;
        cksumtype = ctx->acceptor_subkey_cksumtype;
    } else {
        key = ctx->subkey;
        cksumtype = ctx->cksumtype;
    }
    assert(key != NULL);
    assert(cksumtype != 0);

    kg_iov_msglen(iov, iov_count, &data_length, &assoc_data_length);

    header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
    if (header == NULL)
        return EINVAL;

    padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
    if (padding != NULL)
        padding->buffer.length = 0;

    trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);

    if (toktype == KG_TOK_WRAP_MSG && conf_req_flag) {
        unsigned int k5_headerlen, k5_trailerlen, k5_padlen;
        size_t ec = 0;
        size_t conf_data_length = data_length - assoc_data_length;

        code = krb5_c_crypto_length(context, key->keyblock.enctype,
                                    KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
        if (code != 0)
            goto cleanup;

        code = krb5_c_padding_length(context, key->keyblock.enctype,
                                     conf_data_length + 16 /* E(Header) */, &k5_padlen);
        if (code != 0)
            goto cleanup;

        if (k5_padlen == 0 && (ctx->gss_flags & GSS_C_DCE_STYLE)) {
            /* Windows rejects AEAD tokens with non-zero EC */
            code = krb5_c_block_size(context, key->keyblock.enctype, &ec);
            if (code != 0)
                goto cleanup;
        } else
            ec = k5_padlen;

        code = krb5_c_crypto_length(context, key->keyblock.enctype,
                                    KRB5_CRYPTO_TYPE_TRAILER, &k5_trailerlen);
        if (code != 0)
            goto cleanup;

        gss_headerlen = 16 /* Header */ + k5_headerlen;
        gss_trailerlen = ec + 16 /* E(Header) */ + k5_trailerlen;

        if (trailer == NULL) {
            rrc = gss_trailerlen;
            /* Workaround for Windows bug where it rotates by EC + RRC */
            if (ctx->gss_flags & GSS_C_DCE_STYLE)
                rrc -= ec;
            gss_headerlen += gss_trailerlen;
        }

        if (header->type & GSS_IOV_BUFFER_FLAG_ALLOCATE) {
            code = kg_allocate_iov(header, (size_t) gss_headerlen);
        } else if (header->buffer.length < gss_headerlen)
            code = KRB5_BAD_MSIZE;
        if (code != 0)
            goto cleanup;
        outbuf = (unsigned char *)header->buffer.value;
        header->buffer.length = (size_t) gss_headerlen;

        if (trailer != NULL) {
            if (trailer->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
                code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
            else if (trailer->buffer.length < gss_trailerlen)
                code = KRB5_BAD_MSIZE;
            if (code != 0)
                goto cleanup;
            trailer->buffer.length = (size_t) gss_trailerlen;
        }

        /* TOK_ID */
        store_16_be(KG2_TOK_WRAP_MSG, outbuf);
        /* flags */
        outbuf[2] = (acceptor_flag
                     | (conf_req_flag ? FLAG_WRAP_CONFIDENTIAL : 0)
                     | (ctx->have_acceptor_subkey ? FLAG_ACCEPTOR_SUBKEY : 0));
        /* filler */
        outbuf[3] = 0xFF;
        /* EC */
        store_16_be(ec, outbuf + 4);
        /* RRC */
        store_16_be(0, outbuf + 6);
        store_64_be(ctx->seq_send, outbuf + 8);

        /* EC | copy of header to be encrypted, located in (possibly rotated) trailer */
        if (trailer == NULL)
            tbuf = (unsigned char *)header->buffer.value + 16; /* Header */
        else
            tbuf = (unsigned char *)trailer->buffer.value;

        memset(tbuf, 0xFF, ec);
        memcpy(tbuf + ec, header->buffer.value, 16);

        code = kg_encrypt_iov(context, ctx->proto,
                              ((ctx->gss_flags & GSS_C_DCE_STYLE) != 0),
                              ec, rrc, key, key_usage, 0, iov, iov_count);
        if (code != 0)
            goto cleanup;

        /* RRC */
        store_16_be(rrc, outbuf + 6);

        ctx->seq_send++;
    } else if (toktype == KG_TOK_WRAP_MSG && !conf_req_flag) {
        tok_id = KG2_TOK_WRAP_MSG;

wrap_with_checksum:

        gss_headerlen = 16;

        code = krb5_c_crypto_length(context, key->keyblock.enctype,
                                    KRB5_CRYPTO_TYPE_CHECKSUM,
                                    &gss_trailerlen);
        if (code != 0)
            goto cleanup;

        assert(gss_trailerlen <= 0xFFFF);

        if (trailer == NULL) {
            rrc = gss_trailerlen;
            gss_headerlen += gss_trailerlen;
        }

        if (header->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
            code = kg_allocate_iov(header, (size_t) gss_headerlen);
        else if (header->buffer.length < gss_headerlen)
            code = KRB5_BAD_MSIZE;
        if (code != 0)
            goto cleanup;
        outbuf = (unsigned char *)header->buffer.value;
        header->buffer.length = (size_t) gss_headerlen;

        if (trailer != NULL) {
            if (trailer->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
                code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
            else if (trailer->buffer.length < gss_trailerlen)
                code = KRB5_BAD_MSIZE;
            if (code != 0)
                goto cleanup;
            trailer->buffer.length = (size_t) gss_trailerlen;
        }

        /* TOK_ID */
        store_16_be(tok_id, outbuf);
        /* flags */
        outbuf[2] = (acceptor_flag
                     | (ctx->have_acceptor_subkey ? FLAG_ACCEPTOR_SUBKEY : 0));
        /* filler */
        outbuf[3] = 0xFF;
        if (toktype == KG_TOK_WRAP_MSG) {
            /* Use 0 for checksum calculation, substitute
             * checksum length later.
             */
            /* EC */
            store_16_be(0, outbuf + 4);
            /* RRC */
            store_16_be(0, outbuf + 6);
        } else {
            /* MIC and DEL store 0xFF in EC and RRC */
            store_16_be(0xFFFF, outbuf + 4);
            store_16_be(0xFFFF, outbuf + 6);
        }
        store_64_be(ctx->seq_send, outbuf + 8);

        code = kg_make_checksum_iov_v3(context, cksumtype,
                                       rrc, key, key_usage,
                                       iov, iov_count);
        if (code != 0)
            goto cleanup;

        ctx->seq_send++;

        if (toktype == KG_TOK_WRAP_MSG) {
            /* Fix up EC field */
            store_16_be(gss_trailerlen, outbuf + 4);
            /* Fix up RRC field */
            store_16_be(rrc, outbuf + 6);
        }
    } else if (toktype == KG_TOK_MIC_MSG) {
        tok_id = KG2_TOK_MIC_MSG;
        trailer = NULL;
        goto wrap_with_checksum;
    } else if (toktype == KG_TOK_DEL_CTX) {
        tok_id = KG2_TOK_DEL_CTX;
        goto wrap_with_checksum;
    } else {
        abort();
    }

    code = 0;
    if (conf_state != NULL)
        *conf_state = conf_req_flag;

cleanup:
    if (code != 0)
        kg_release_iov(iov, iov_count);

    return code;
}
Exemplo n.º 7
0
OM_uint32
gss_krb5int_unseal_v3_iov(krb5_context context,
                          OM_uint32 *minor_status,
                          krb5_gss_ctx_id_rec *ctx,
                          gss_iov_buffer_desc *iov,
                          int iov_count,
                          int *conf_state,
                          gss_qop_t *qop_state,
                          int toktype)
{
    OM_uint32 code;
    gss_iov_buffer_t header;
    gss_iov_buffer_t padding;
    gss_iov_buffer_t trailer;
    unsigned char acceptor_flag;
    unsigned char *ptr = NULL;
    int key_usage;
    size_t rrc, ec;
    size_t data_length, assoc_data_length;
    krb5_key key;
    gssint_uint64 seqnum;
    krb5_boolean valid;
    krb5_cksumtype cksumtype;
    int conf_flag = 0;

    if (ctx->big_endian != 0)
        return GSS_S_DEFECTIVE_TOKEN;

    if (qop_state != NULL)
        *qop_state = GSS_C_QOP_DEFAULT;

    header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
    assert(header != NULL);

    padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
    if (padding != NULL && padding->buffer.length != 0)
        return GSS_S_DEFECTIVE_TOKEN;

    trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);

    acceptor_flag = ctx->initiate ? FLAG_SENDER_IS_ACCEPTOR : 0;
    key_usage = (toktype == KG_TOK_WRAP_MSG
                 ? (!ctx->initiate
                    ? KG_USAGE_INITIATOR_SEAL
                    : KG_USAGE_ACCEPTOR_SEAL)
                 : (!ctx->initiate
                    ? KG_USAGE_INITIATOR_SIGN
                    : KG_USAGE_ACCEPTOR_SIGN));

    kg_iov_msglen(iov, iov_count, &data_length, &assoc_data_length);

    ptr = (unsigned char *)header->buffer.value;

    if (header->buffer.length < 16) {
        *minor_status = 0;
        return GSS_S_DEFECTIVE_TOKEN;
    }

    if ((ptr[2] & FLAG_SENDER_IS_ACCEPTOR) != acceptor_flag) {
        *minor_status = (OM_uint32)G_BAD_DIRECTION;
        return GSS_S_BAD_SIG;
    }

    if (ctx->have_acceptor_subkey && (ptr[2] & FLAG_ACCEPTOR_SUBKEY)) {
        key = ctx->acceptor_subkey;
        cksumtype = ctx->acceptor_subkey_cksumtype;
    } else {
        key = ctx->subkey;
        cksumtype = ctx->cksumtype;
    }
    assert(key != NULL);


    if (toktype == KG_TOK_WRAP_MSG) {
        unsigned int k5_trailerlen;

        if (load_16_be(ptr) != KG2_TOK_WRAP_MSG)
            goto defective;
        conf_flag = ((ptr[2] & FLAG_WRAP_CONFIDENTIAL) != 0);
        if (ptr[3] != 0xFF)
            goto defective;
        ec = load_16_be(ptr + 4);
        rrc = load_16_be(ptr + 6);
        seqnum = load_64_be(ptr + 8);

        code = krb5_c_crypto_length(context, key->keyblock.enctype,
                                    conf_flag ? KRB5_CRYPTO_TYPE_TRAILER :
                                    KRB5_CRYPTO_TYPE_CHECKSUM,
                                    &k5_trailerlen);
        if (code != 0) {
            *minor_status = code;
            return GSS_S_FAILURE;
        }

        /* Deal with RRC */
        if (trailer == NULL) {
            size_t desired_rrc = k5_trailerlen;

            if (conf_flag) {
                desired_rrc += 16; /* E(Header) */

                if ((ctx->gss_flags & GSS_C_DCE_STYLE) == 0)
                    desired_rrc += ec;
            }

            /* According to MS, we only need to deal with a fixed RRC for DCE */
            if (rrc != desired_rrc)
                goto defective;
        } else if (rrc != 0) {
            /* Should have been rotated by kg_unseal_stream_iov() */
            goto defective;
        }

        if (conf_flag) {
            unsigned char *althdr;

            /* Decrypt */
            code = kg_decrypt_iov(context, ctx->proto,
                                  ((ctx->gss_flags & GSS_C_DCE_STYLE) != 0),
                                  ec, rrc,
                                  key, key_usage, 0, iov, iov_count);
            if (code != 0) {
                *minor_status = code;
                return GSS_S_BAD_SIG;
            }

            /* Validate header integrity */
            if (trailer == NULL)
                althdr = (unsigned char *)header->buffer.value + 16 + ec;
            else
                althdr = (unsigned char *)trailer->buffer.value + ec;

            if (load_16_be(althdr) != KG2_TOK_WRAP_MSG
                    || althdr[2] != ptr[2]
                    || althdr[3] != ptr[3]
                    || memcmp(althdr + 8, ptr + 8, 8) != 0) {
                *minor_status = 0;
                return GSS_S_BAD_SIG;
            }
        } else {
            /* Verify checksum: note EC is checksum size here, not padding */
            if (ec != k5_trailerlen)
                goto defective;

            /* Zero EC, RRC before computing checksum */
            store_16_be(0, ptr + 4);
            store_16_be(0, ptr + 6);

            code = kg_verify_checksum_iov_v3(context, cksumtype, rrc,
                                             key, key_usage,
                                             iov, iov_count, &valid);
            if (code != 0 || valid == FALSE) {
                *minor_status = code;
                return GSS_S_BAD_SIG;
            }
        }

        code = g_order_check(&ctx->seqstate, seqnum);
    } else if (toktype == KG_TOK_MIC_MSG) {
        if (load_16_be(ptr) != KG2_TOK_MIC_MSG)
            goto defective;

verify_mic_1:
        if (ptr[3] != 0xFF)
            goto defective;
        seqnum = load_64_be(ptr + 8);

        code = kg_verify_checksum_iov_v3(context, cksumtype, 0,
                                         key, key_usage,
                                         iov, iov_count, &valid);
        if (code != 0 || valid == FALSE) {
            *minor_status = code;
            return GSS_S_BAD_SIG;
        }
        code = g_order_check(&ctx->seqstate, seqnum);
    } else if (toktype == KG_TOK_DEL_CTX) {
        if (load_16_be(ptr) != KG2_TOK_DEL_CTX)
            goto defective;
        goto verify_mic_1;
    } else {
        goto defective;
    }

    *minor_status = 0;

    if (conf_state != NULL)
        *conf_state = conf_flag;

    return code;

defective:
    *minor_status = 0;

    return GSS_S_DEFECTIVE_TOKEN;
}