/*

 *  Debugging routines

 *

 *  Copyright The Mbed TLS Contributors

 *  SPDX-License-Identifier: Apache-2.0

 *

 *  Licensed under the Apache License, Version 2.0 (the "License"); you may

 *  not use this file except in compliance with the License.

 *  You may obtain a copy of the License at

 *

 *  http://www.apache.org/licenses/LICENSE-2.0

 *

 *  Unless required by applicable law or agreed to in writing, software

 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT

 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 *  See the License for the specific language governing permissions and

 *  limitations under the License.

 */

#include "common.h"

#if defined(MBEDTLS_DEBUG_C)

#include "mbedtls/platform.h"

#include "mbedtls/debug.h"

#include "mbedtls/error.h"

#include <stdarg.h>

#include <stdio.h>

#include <string.h>

#define DEBUG_BUF_SIZE      512

static int debug_threshold = 0;

void mbedtls_debug_set_threshold(int threshold)

{

    debug_threshold = threshold;

}

/*

 * All calls to f_dbg must be made via this function

 */

static inline void debug_send_line(const mbedtls_ssl_context *ssl, int level,

                                   const char *file, int line,

                                   const char *str)

{

    /*

     * If in a threaded environment, we need a thread identifier.

     * Since there is no portable way to get one, use the address of the ssl

     * context instead, as it shouldn't be shared between threads.

     */

#if defined(MBEDTLS_THREADING_C)

    char idstr[20 + DEBUG_BUF_SIZE]; /* 0x + 16 nibbles + ': ' */

    mbedtls_snprintf(idstr, sizeof(idstr), "%p: %s", (void *) ssl, str);

    ssl->conf->f_dbg(ssl->conf->p_dbg, level, file, line, idstr);

#else

    ssl->conf->f_dbg(ssl->conf->p_dbg, level, file, line, str);

#endif

}

MBEDTLS_PRINTF_ATTRIBUTE(5, 6)

void mbedtls_debug_print_msg(const mbedtls_ssl_context *ssl, int level,

                             const char *file, int line,

                             const char *format, ...)

{

    va_list argp;

    char str[DEBUG_BUF_SIZE];

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    if (NULL == ssl              ||

        NULL == ssl->conf        ||

        NULL == ssl->conf->f_dbg ||

        level > debug_threshold) {

        return;

    }

    va_start(argp, format);

    ret = mbedtls_vsnprintf(str, DEBUG_BUF_SIZE, format, argp);

    va_end(argp);

    if (ret >= 0 && ret < DEBUG_BUF_SIZE - 1) {

        str[ret]     = '\n';

        str[ret + 1] = '\0';

    }

    debug_send_line(ssl, level, file, line, str);

}

void mbedtls_debug_print_ret(const mbedtls_ssl_context *ssl, int level,

                             const char *file, int line,

                             const char *text, int ret)

{

    char str[DEBUG_BUF_SIZE];

    if (NULL == ssl              ||

        NULL == ssl->conf        ||

        NULL == ssl->conf->f_dbg ||

        level > debug_threshold) {

        return;

    }

    /*

     * With non-blocking I/O and examples that just retry immediately,

     * the logs would be quickly flooded with WANT_READ, so ignore that.

     * Don't ignore WANT_WRITE however, since it is usually rare.

     */

    if (ret == MBEDTLS_ERR_SSL_WANT_READ) {

        return;

    }

    mbedtls_snprintf(str, sizeof(str), "%s() returned %d (-0x%04x)\n",

                     text, ret, (unsigned int) -ret);

    debug_send_line(ssl, level, file, line, str);

}

void mbedtls_debug_print_buf(const mbedtls_ssl_context *ssl, int level,

                             const char *file, int line, const char *text,

                             const unsigned char *buf, size_t len)

{

    char str[DEBUG_BUF_SIZE];

    char txt[17];

    size_t i, idx = 0;

    if (NULL == ssl              ||

        NULL == ssl->conf        ||

        NULL == ssl->conf->f_dbg ||

        level > debug_threshold) {

        return;

    }

    mbedtls_snprintf(str + idx, sizeof(str) - idx, "dumping '%s' (%u bytes)\n",

                     text, (unsigned int) len);

    debug_send_line(ssl, level, file, line, str);

    idx = 0;

    memset(txt, 0, sizeof(txt));

    for (i = 0; i < len; i++) {

        if (i >= 4096) {

            break;

        }

        if (i % 16 == 0) {

            if (i > 0) {

                mbedtls_snprintf(str + idx, sizeof(str) - idx, "  %s\n", txt);

                debug_send_line(ssl, level, file, line, str);

                idx = 0;

                memset(txt, 0, sizeof(txt));

            }

            idx += mbedtls_snprintf(str + idx, sizeof(str) - idx, "%04x: ",

                                    (unsigned int) i);

        }

        idx += mbedtls_snprintf(str + idx, sizeof(str) - idx, " %02x",

                                (unsigned int) buf[i]);

        txt[i % 16] = (buf[i] > 31 && buf[i] < 127) ? buf[i] : '.';

    }

    if (len > 0) {

        for (/* i = i */; i % 16 != 0; i++) {

            idx += mbedtls_snprintf(str + idx, sizeof(str) - idx, "   ");

        }

        mbedtls_snprintf(str + idx, sizeof(str) - idx, "  %s\n", txt);

        debug_send_line(ssl, level, file, line, str);

    }

}

#if defined(MBEDTLS_ECP_C)

void mbedtls_debug_print_ecp(const mbedtls_ssl_context *ssl, int level,

                             const char *file, int line,

                             const char *text, const mbedtls_ecp_point *X)

{

    char str[DEBUG_BUF_SIZE];

    if (NULL == ssl              ||

        NULL == ssl->conf        ||

        NULL == ssl->conf->f_dbg ||

        level > debug_threshold) {

        return;

    }

    mbedtls_snprintf(str, sizeof(str), "%s(X)", text);

    mbedtls_debug_print_mpi(ssl, level, file, line, str, &X->X);

    mbedtls_snprintf(str, sizeof(str), "%s(Y)", text);

    mbedtls_debug_print_mpi(ssl, level, file, line, str, &X->Y);

}

#endif /* MBEDTLS_ECP_C */

#if defined(MBEDTLS_BIGNUM_C)

void mbedtls_debug_print_mpi(const mbedtls_ssl_context *ssl, int level,

                             const char *file, int line,

                             const char *text, const mbedtls_mpi *X)

{

    char str[DEBUG_BUF_SIZE];

    size_t bitlen;

    size_t idx = 0;

    if (NULL == ssl              ||

        NULL == ssl->conf        ||

        NULL == ssl->conf->f_dbg ||

        NULL == X                ||

        level > debug_threshold) {

        return;

    }

    bitlen = mbedtls_mpi_bitlen(X);

    mbedtls_snprintf(str, sizeof(str), "value of '%s' (%u bits) is:\n",

                     text, (unsigned) bitlen);

    debug_send_line(ssl, level, file, line, str);

    if (bitlen == 0) {

        str[0] = ' '; str[1] = '0'; str[2] = '0';

        idx = 3;

    } else {

        int n;

        for (n = (int) ((bitlen - 1) / 8); n >= 0; n--) {

            size_t limb_offset = n / sizeof(mbedtls_mpi_uint);

            size_t offset_in_limb = n % sizeof(mbedtls_mpi_uint);

            unsigned char octet =

                (X->p[limb_offset] >> (offset_in_limb * 8)) & 0xff;

            mbedtls_snprintf(str + idx, sizeof(str) - idx, " %02x", octet);

            idx += 3;

            /* Wrap lines after 16 octets that each take 3 columns */

            if (idx >= 3 * 16) {

                mbedtls_snprintf(str + idx, sizeof(str) - idx, "\n");

                debug_send_line(ssl, level, file, line, str);

                idx = 0;

            }

        }

    }

    if (idx != 0) {

        mbedtls_snprintf(str + idx, sizeof(str) - idx, "\n");

        debug_send_line(ssl, level, file, line, str);

    }

}

#endif /* MBEDTLS_BIGNUM_C */

#if defined(MBEDTLS_X509_CRT_PARSE_C) && !defined(MBEDTLS_X509_REMOVE_INFO)

static void debug_print_pk(const mbedtls_ssl_context *ssl, int level,

                           const char *file, int line,

                           const char *text, const mbedtls_pk_context *pk)

{

    size_t i;

    mbedtls_pk_debug_item items[MBEDTLS_PK_DEBUG_MAX_ITEMS];

    char name[16];

    memset(items, 0, sizeof(items));

    if (mbedtls_pk_debug(pk, items) != 0) {

        debug_send_line(ssl, level, file, line,

                        "invalid PK context\n");

        return;

    }

    for (i = 0; i < MBEDTLS_PK_DEBUG_MAX_ITEMS; i++) {

        if (items[i].type == MBEDTLS_PK_DEBUG_NONE) {

            return;

        }

        mbedtls_snprintf(name, sizeof(name), "%s%s", text, items[i].name);

        name[sizeof(name) - 1] = '\0';

        if (items[i].type == MBEDTLS_PK_DEBUG_MPI) {

            mbedtls_debug_print_mpi(ssl, level, file, line, name, items[i].value);

        } else

#if defined(MBEDTLS_ECP_C)

        if (items[i].type == MBEDTLS_PK_DEBUG_ECP) {

            mbedtls_debug_print_ecp(ssl, level, file, line, name, items[i].value);

        } else

#endif

        { debug_send_line(ssl, level, file, line,

                          "should not happen\n"); }

    }

}

static void debug_print_line_by_line(const mbedtls_ssl_context *ssl, int level,

                                     const char *file, int line, const char *text)

{

    char str[DEBUG_BUF_SIZE];

    const char *start, *cur;

    start = text;

    for (cur = text; *cur != '\0'; cur++) {

        if (*cur == '\n') {

            size_t len = cur - start + 1;

            if (len > DEBUG_BUF_SIZE - 1) {

                len = DEBUG_BUF_SIZE - 1;

            }

            memcpy(str, start, len);

            str[len] = '\0';

            debug_send_line(ssl, level, file, line, str);

            start = cur + 1;

        }

    }

}

void mbedtls_debug_print_crt(const mbedtls_ssl_context *ssl, int level,

                             const char *file, int line,

                             const char *text, const mbedtls_x509_crt *crt)

{

    char str[DEBUG_BUF_SIZE];

    int i = 0;

    if (NULL == ssl              ||

        NULL == ssl->conf        ||

        NULL == ssl->conf->f_dbg ||

        NULL == crt              ||

        level > debug_threshold) {

        return;

    }

    while (crt != NULL) {

        char buf[1024];

        mbedtls_snprintf(str, sizeof(str), "%s #%d:\n", text, ++i);

        debug_send_line(ssl, level, file, line, str);

        mbedtls_x509_crt_info(buf, sizeof(buf) - 1, "", crt);

        debug_print_line_by_line(ssl, level, file, line, buf);

        debug_print_pk(ssl, level, file, line, "crt->", &crt->pk);

        crt = crt->next;

    }

}

#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_X509_REMOVE_INFO */

#if defined(MBEDTLS_ECDH_C)

static void mbedtls_debug_printf_ecdh_internal(const mbedtls_ssl_context *ssl,

                                               int level, const char *file,

                                               int line,

                                               const mbedtls_ecdh_context *ecdh,

                                               mbedtls_debug_ecdh_attr attr)

{

#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)

    const mbedtls_ecdh_context *ctx = ecdh;

#else

    const mbedtls_ecdh_context_mbed *ctx = &ecdh->ctx.mbed_ecdh;

#endif

    switch (attr) {

        case MBEDTLS_DEBUG_ECDH_Q:

            mbedtls_debug_print_ecp(ssl, level, file, line, "ECDH: Q",

                                    &ctx->Q);

            break;

        case MBEDTLS_DEBUG_ECDH_QP:

            mbedtls_debug_print_ecp(ssl, level, file, line, "ECDH: Qp",

                                    &ctx->Qp);

            break;

        case MBEDTLS_DEBUG_ECDH_Z:

            mbedtls_debug_print_mpi(ssl, level, file, line, "ECDH: z",

                                    &ctx->z);

            break;

        default:

            break;

    }

}

void mbedtls_debug_printf_ecdh(const mbedtls_ssl_context *ssl, int level,

                               const char *file, int line,

                               const mbedtls_ecdh_context *ecdh,

                               mbedtls_debug_ecdh_attr attr)

{

#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)

    mbedtls_debug_printf_ecdh_internal(ssl, level, file, line, ecdh, attr);

#else

    switch (ecdh->var) {

        default:

            mbedtls_debug_printf_ecdh_internal(ssl, level, file, line, ecdh,

                                               attr);

    }

#endif

}

#endif /* MBEDTLS_ECDH_C */

#endif /* MBEDTLS_DEBUG_C */