File content as of revision 7:1af47e3a19b6:

// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

#include <stdlib.h>
#ifdef _CRTDBG_MAP_ALLOC
#include <crtdbg.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include "azure_c_shared_utility/httpapi.h"
#include "azure_c_shared_utility/httpheaders.h"
#include "azure_c_shared_utility/crt_abstractions.h"
#include "azure_c_shared_utility/xlogging.h"
#include "azure_c_shared_utility/xio.h"
#include "azure_c_shared_utility/platform.h"
#include "azure_c_shared_utility/tlsio.h"
#include "azure_c_shared_utility/threadapi.h"
#include <string.h>
#include <limits.h>

#define MAX_HOSTNAME     64
#define TEMP_BUFFER_SIZE 4096

#define CHAR_COUNT(A)   (sizeof(A) - 1)

DEFINE_ENUM_STRINGS(HTTPAPI_RESULT, HTTPAPI_RESULT_VALUES)

typedef enum SEND_ALL_RESULT_TAG
{
    SEND_ALL_RESULT_NOT_STARTED,
    SEND_ALL_RESULT_PENDING,
    SEND_ALL_RESULT_OK,
    SEND_ALL_RESULT_ERROR
} SEND_ALL_RESULT;

typedef struct HTTP_HANDLE_DATA_TAG
{
    char            host[MAX_HOSTNAME];
    char*           certificate;
    XIO_HANDLE      xio_handle;
    size_t          received_bytes_count;
    unsigned char*  received_bytes;
    SEND_ALL_RESULT send_all_result;
    unsigned int    is_io_error : 1;
    unsigned int    is_connected : 1;
} HTTP_HANDLE_DATA;

/*the following function does the same as sscanf(pos2, "%d", &sec)*/
/*this function only exists because some of platforms do not have sscanf. */
static int ParseStringToDecimal(const char *src, int* dst)
{
    char* next;
    (*dst) = strtol(src, &next, 0);
    if ((src == next) || ((((*dst) == LONG_MAX) || ((*dst) == LONG_MIN)) && (errno != 0)))
    {
        return EOF;
    }
    return 1;
}

/*the following function does the same as sscanf(pos2, "%x", &sec)*/
/*this function only exists because some of platforms do not have sscanf. This is not a full implementation; it only works with well-defined x numbers. */
#define HEXA_DIGIT_VAL(c)         (((c>='0') && (c<='9')) ? (c-'0') : ((c>='a') && (c<='f')) ? (c-'a'+10) : ((c>='A') && (c<='F')) ? (c-'A'+10) : -1)
static int ParseStringToHexadecimal(const char *src, int* dst)
{
    if (src == NULL)
        return EOF;
    if (HEXA_DIGIT_VAL(*src) == -1)
        return EOF;

    int digitVal;
    (*dst) = 0;
    while ((digitVal = HEXA_DIGIT_VAL(*src)) != -1)
    {
        (*dst) *= 0x10;
        (*dst) += digitVal;
        src++;
    }
    return 1;
}

/*the following function does the same as sscanf(buf, "HTTP/%*d.%*d %d %*[^\r\n]", &ret) */
/*this function only exists because some of platforms do not have sscanf. This is not a full implementation; it only works with well-defined HTTP response. */
static int ParseHttpResponse(const char* src, int* dst)
{
    const char* prefix = "HTTP/";
    while ((*prefix) != '\0')
    {
        if ((*prefix) != (*src))
            return EOF;
        prefix++;
        src++;
    }

    while ((*src) != '.')
    {
        if ((*src) == '\0')
            return EOF;
    }

    while ((*src) != ' ')
    {
        if ((*src) == '\0')
            return EOF;
    }

    return ParseStringToDecimal(src, dst);
}

HTTPAPI_RESULT HTTPAPI_Init(void)
{
    return HTTPAPI_OK;
}

void HTTPAPI_Deinit(void)
{
}

HTTP_HANDLE HTTPAPI_CreateConnection(const char* hostName)
{
    HTTP_HANDLE_DATA* handle = NULL;

    if (hostName)
    {
        handle = (HTTP_HANDLE_DATA*)malloc(sizeof(HTTP_HANDLE_DATA));
        if (handle != NULL)
        {
            if (strcpy_s(handle->host, MAX_HOSTNAME, hostName) != 0)
            {
                LogError("HTTPAPI_CreateConnection::Could not strcpy_s");
                free(handle);
                handle = NULL;
            }
            else
            {
                TLSIO_CONFIG tlsio_config = { hostName, 443 };
                handle->xio_handle = xio_create(platform_get_default_tlsio(), (void*)&tlsio_config);
                if (handle->xio_handle == NULL)
                {
                    LogError("HTTPAPI_CreateConnection::xio_create failed");
                    free(handle->host);
                    free(handle);
                    handle = NULL;
                }
                else
                {
                    handle->is_connected = 0;
                    handle->is_io_error = 0;
                    handle->received_bytes_count = 0;
                    handle->received_bytes = NULL;
                    handle->send_all_result = SEND_ALL_RESULT_NOT_STARTED;
                    handle->certificate = NULL;
                }
            }
        }
    }
    else
    {
        LogInfo("HTTPAPI_CreateConnection:: null hostName parameter");
    }

    return (HTTP_HANDLE)handle;
}

void HTTPAPI_CloseConnection(HTTP_HANDLE handle)
{
    HTTP_HANDLE_DATA* h = (HTTP_HANDLE_DATA*)handle;

    if (h)
    {
        if (h->xio_handle != NULL)
        {
            LogInfo("HTTPAPI_CloseConnection xio_destroy(); to %s", h->host);
            xio_destroy(h->xio_handle);
        }

        if (h->certificate)
        {
            free(h->certificate);
        }

        free(h);
    }
}

static void on_io_open_complete(void* context, IO_OPEN_RESULT open_result)
{
    HTTP_HANDLE_DATA* h = (HTTP_HANDLE_DATA*)context;
    if (open_result == IO_OPEN_OK)
    {
        h->is_connected = 1;
        h->is_io_error = 0;
    }
    else
    {
        h->is_io_error = 1;
    }
}

static int my_strnicmp(const char* s1, const char* s2, size_t n)
{
    size_t i;
    int result = 0;

    for (i = 0; i < n; i++)
    {
        /* compute the difference between the chars */
        result = tolower(s1[i]) - tolower(s2[i]);

        /* break if we have a difference ... */
        if ((result != 0) ||
            /* ... or if we got to the end of one the strings */
            (s1[i] == '\0') || (s2[i] == '\0'))
        {
            break;
        }
    }

    return result;
}

static int my_stricmp(const char* s1, const char* s2)
{
    size_t i = 0;

    while ((s1[i] != '\0') && (s2[i] != '\0'))
    {
        /* break if we have a difference ... */
        if (tolower(s1[i]) != tolower(s2[i]))
        {
            break;
        }

        i++;
    }

    /* if we broke because we are at end of string this will yield 0 */
    /* if we broke because there was a difference this will yield non-zero  */
    return tolower(s1[i]) - tolower(s2[i]);
}

static void on_bytes_received(void* context, const unsigned char* buffer, size_t size)
{
    HTTP_HANDLE_DATA* h = (HTTP_HANDLE_DATA*)context;

    /* Here we got some bytes so we'll buffer them so the receive functions can consumer it */
    unsigned char* new_received_bytes = (unsigned char*)realloc(h->received_bytes, h->received_bytes_count + size);
    if (new_received_bytes == NULL)
    {
        h->is_io_error = 1;
        LogError("on_bytes_received: Error allocating memory for received data");
    }
    else
    {
        h->received_bytes = new_received_bytes;
        (void)memcpy(h->received_bytes + h->received_bytes_count, buffer, size);
        h->received_bytes_count += size;
    }
}

static void on_io_error(void* context)
{
    HTTP_HANDLE_DATA* h = (HTTP_HANDLE_DATA*)context;
    h->is_io_error = 1;
    LogError("on_io_error: Error signalled by underlying IO");
}

static int conn_receive(HTTP_HANDLE_DATA* http_instance, char* buffer, int count)
{
    int result = 0;

    if (count < 0)
    {
        result = -1;
    }
    else
    {
        while (result < count)
        {
            xio_dowork(http_instance->xio_handle);

            /* if any error was detected while receiving then simply break and report it */
            if (http_instance->is_io_error != 0)
            {
                result = -1;
                break;
            }

            if (http_instance->received_bytes_count >= (size_t)count)
            {
                /* Consuming bytes from the receive buffer */
                (void)memcpy(buffer, http_instance->received_bytes, count);
                (void)memmove(http_instance->received_bytes, http_instance->received_bytes + count, http_instance->received_bytes_count - count);
                http_instance->received_bytes_count -= count;

                /* we're not reallocating at each consumption so that we don't trash due to byte by byte consumption */
                if (http_instance->received_bytes_count == 0)
                {
                    free(http_instance->received_bytes);
                    http_instance->received_bytes = NULL;
                }

                result = count;
                break;
            }

            ThreadAPI_Sleep(1);
        }
    }

    return result;
}

static void on_send_complete(void* context, IO_SEND_RESULT send_result)
{
    /* If a send is complete we'll simply signal this by changing the send all state */
    HTTP_HANDLE_DATA* http_instance = (HTTP_HANDLE_DATA*)context;
    if (send_result == IO_SEND_OK)
    {
        http_instance->send_all_result = SEND_ALL_RESULT_OK;
    }
    else
    {
        http_instance->send_all_result = SEND_ALL_RESULT_ERROR;
    }
}

static int conn_send_all(HTTP_HANDLE_DATA* http_instance, char* buffer, int count)
{
    int result;

    if (count < 0)
    {
        result = -1;
    }
    else
    {
        http_instance->send_all_result = SEND_ALL_RESULT_PENDING;
        if (xio_send(http_instance->xio_handle, buffer, count, on_send_complete, http_instance) != 0)
        {
            result = -1;
        }
        else
        {
            /* We have to loop in here until all bytes are sent or we encounter an error. */
            while (1)
            {
                xio_dowork(http_instance->xio_handle);

                /* If we got an error signalled from the underlying IO we simply report it up */
                if (http_instance->is_io_error)
                {
                    http_instance->send_all_result = SEND_ALL_RESULT_ERROR;
                    break;
                }

                if (http_instance->send_all_result != SEND_ALL_RESULT_PENDING)
                {
                    break;
                }

                /* We yield the CPU for a bit so others can do their work */
                ThreadAPI_Sleep(1);
            }

            /* The send_all_result indicates what is the status for the send operation.
               Not started - means nothing should happen since no send was started
               Pending - a send was started, but it is still being carried out 
               Ok - Send complete
               Error - error */
            switch (http_instance->send_all_result)
            {
                default:
                case SEND_ALL_RESULT_NOT_STARTED:
                    result = -1;
                    break;

                case SEND_ALL_RESULT_OK:
                    result = count;
                    break;

                case SEND_ALL_RESULT_ERROR:
                    result = -1;
                    break;
            }
        }
    }

    return result;
}

static int readLine(HTTP_HANDLE_DATA* http_instance, char* buf, const size_t size)
{
    // reads until \r\n is encountered. writes in buf all the characters
    char* p = buf;
    char  c;
    if (conn_receive(http_instance, &c, 1) < 0)
        return -1;
    while (c != '\r') {
        if ((p - buf + 1) >= (int)size)
            return -1;
        *p++ = c;
        if (conn_receive(http_instance, &c, 1) < 0)
            return -1;
    }
    *p = 0;
    if (conn_receive(http_instance, &c, 1) < 0 || c != '\n') // skip \n
        return -1;
    return p - buf;
}

static int readChunk(HTTP_HANDLE_DATA* http_instance, char* buf, size_t size)
{
    size_t cur, offset;

    // read content with specified length, even if it is received
    // only in chunks due to fragmentation in the networking layer.
    // returns -1 in case of error.
    offset = 0;
    while (size > 0)
    {
        cur = conn_receive(http_instance, buf + offset, size);

        // end of stream reached
        if (cur == 0)
            return offset;

        // read cur bytes (might be less than requested)
        size -= cur;
        offset += cur;
    }

    return offset;
}

static int skipN(HTTP_HANDLE_DATA* http_instance, size_t n, char* buf, size_t size)
{
    size_t org = n;
    // read and abandon response content with specified length
    // returns -1 in case of error.
    while (n > size)
    {
        if (readChunk(http_instance, (char*)buf, size) < 0)
            return -1;

        n -= size;
    }

    if (readChunk(http_instance, (char*)buf, n) < 0)
        return -1;

    return org;
}

//Note: This function assumes that "Host:" and "Content-Length:" headers are setup
//      by the caller of HTTPAPI_ExecuteRequest() (which is true for httptransport.c).
HTTPAPI_RESULT HTTPAPI_ExecuteRequest(HTTP_HANDLE handle, HTTPAPI_REQUEST_TYPE requestType, const char* relativePath,
    HTTP_HEADERS_HANDLE httpHeadersHandle, const unsigned char* content,
    size_t contentLength, unsigned int* statusCode,
    HTTP_HEADERS_HANDLE responseHeadersHandle, BUFFER_HANDLE responseContent)
{

    HTTPAPI_RESULT result;
    size_t  headersCount;
    char    buf[TEMP_BUFFER_SIZE];
    int     ret;
    size_t  bodyLength = 0;
    bool    chunked = false;
    const unsigned char* receivedContent;

    const char* method = (requestType == HTTPAPI_REQUEST_GET) ? "GET"
        : (requestType == HTTPAPI_REQUEST_POST) ? "POST"
        : (requestType == HTTPAPI_REQUEST_PUT) ? "PUT"
        : (requestType == HTTPAPI_REQUEST_DELETE) ? "DELETE"
        : (requestType == HTTPAPI_REQUEST_PATCH) ? "PATCH"
        : NULL;

    if (handle == NULL ||
        relativePath == NULL ||
        httpHeadersHandle == NULL ||
        method == NULL ||
        HTTPHeaders_GetHeaderCount(httpHeadersHandle, &headersCount) != HTTP_HEADERS_OK)
    {
        result = HTTPAPI_INVALID_ARG;
        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
        goto exit;
    }

    HTTP_HANDLE_DATA* httpHandle = (HTTP_HANDLE_DATA*)handle;

    if (handle->is_connected == 0)
    {
        // Load the certificate
        if ((httpHandle->certificate != NULL) &&
			(xio_setoption(httpHandle->xio_handle, "TrustedCerts", httpHandle->certificate) != 0))
        {
            result = HTTPAPI_ERROR;
            LogError("Could not load certificate (result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
            goto exit;
        }

        // Make the connection
        if (xio_open(httpHandle->xio_handle, on_io_open_complete, httpHandle, on_bytes_received, httpHandle, on_io_error, httpHandle) != 0)
        {
            result = HTTPAPI_ERROR;
            LogError("Could not connect (result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
            goto exit;
        }

        while (1)
        {
            xio_dowork(httpHandle->xio_handle);
            if ((handle->is_connected == 1) ||
                (handle->is_io_error == 1))
            {
                break;
            }

            ThreadAPI_Sleep(1);
        }
    }

    //Send request
    if ((ret = snprintf(buf, sizeof(buf), "%s %s HTTP/1.1\r\n", method, relativePath)) < 0
        || ret >= sizeof(buf))
    {
        result = HTTPAPI_STRING_PROCESSING_ERROR;
        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
        goto exit;
    }
    if (conn_send_all(httpHandle, buf, strlen(buf)) < 0)
    {
        result = HTTPAPI_SEND_REQUEST_FAILED;
        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
        goto exit;
    }

    //Send default headers
    for (size_t i = 0; i < headersCount; i++)
    {
        char* header;
        if (HTTPHeaders_GetHeader(httpHeadersHandle, i, &header) != HTTP_HEADERS_OK)
        {
            result = HTTPAPI_HTTP_HEADERS_FAILED;
            LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
            goto exit;
        }
        if (conn_send_all(httpHandle, header, strlen(header)) < 0)
        {
            result = HTTPAPI_SEND_REQUEST_FAILED;
            LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
            free(header);
            goto exit;
        }
        if (conn_send_all(httpHandle, "\r\n", 2) < 0)
        {
            result = HTTPAPI_SEND_REQUEST_FAILED;
            LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
            free(header);
            goto exit;
        }
        free(header);
    }

    //Close headers
    if (conn_send_all(httpHandle, "\r\n", 2) < 0)
    {
        result = HTTPAPI_SEND_REQUEST_FAILED;
        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
        goto exit;
    }

    //Send data (if available)
    if (content && contentLength > 0)
    {
        if (conn_send_all(httpHandle, (char*)content, contentLength) < 0)
        {
            result = HTTPAPI_SEND_REQUEST_FAILED;
            LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
            goto exit;
        }
    }

    //Receive response
    if (readLine(httpHandle, buf, sizeof(buf)) < 0)
    {
        result = HTTPAPI_READ_DATA_FAILED;
        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
        goto exit;
    }

    //Parse HTTP response
    if (ParseHttpResponse(buf, &ret) != 1)
    {
        //Cannot match string, error
        LogInfo("HTTPAPI_ExecuteRequest::Not a correct HTTP answer=%s", buf);
        result = HTTPAPI_READ_DATA_FAILED;
        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
        goto exit;
    }
    if (statusCode)
        *statusCode = ret;

    //Read HTTP response headers
    if (readLine(httpHandle, buf, sizeof(buf)) < 0)
    {
        result = HTTPAPI_READ_DATA_FAILED;
        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
        goto exit;
    }

    while (buf[0])
    {
        const char ContentLength[] = "content-length:";
        const char TransferEncoding[] = "transfer-encoding:";

        if (my_strnicmp(buf, ContentLength, CHAR_COUNT(ContentLength)) == 0)
        {
            if (ParseStringToDecimal(buf + CHAR_COUNT(ContentLength), &bodyLength) != 1)
            {
                result = HTTPAPI_READ_DATA_FAILED;
                LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                goto exit;
            }
        }
        else if (my_strnicmp(buf, TransferEncoding, CHAR_COUNT(TransferEncoding)) == 0)
        {
            const char* p = buf + CHAR_COUNT(TransferEncoding);
            while (isspace(*p)) p++;
            if (my_stricmp(p, "chunked") == 0)
                chunked = true;
        }

        char* whereIsColon = strchr((char*)buf, ':');
        if (whereIsColon && responseHeadersHandle != NULL)
        {
            *whereIsColon = '\0';
            HTTPHeaders_AddHeaderNameValuePair(responseHeadersHandle, buf, whereIsColon + 1);
        }

        if (readLine(httpHandle, buf, sizeof(buf)) < 0)
        {
            result = HTTPAPI_READ_DATA_FAILED;
            LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
            goto exit;
        }
    }

    //Read HTTP response body
    if (!chunked)
    {
        if (bodyLength)
        {
            if (responseContent != NULL)
            {
                if (BUFFER_pre_build(responseContent, bodyLength) != 0)
                {
                    result = HTTPAPI_ALLOC_FAILED;
                    LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                }
                else if (BUFFER_content(responseContent, &receivedContent) != 0)
                {
                    (void)BUFFER_unbuild(responseContent);

                    result = HTTPAPI_ALLOC_FAILED;
                    LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                }

                if (readChunk(httpHandle, (char*)receivedContent, bodyLength) < 0)
                {
                    result = HTTPAPI_READ_DATA_FAILED;
                    LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                    goto exit;
                }
                else
                {
                    result = HTTPAPI_OK;
                }
            }
            else
            {
                (void)skipN(httpHandle, bodyLength, buf, sizeof(buf));
                result = HTTPAPI_OK;
            }
        }
        else
        {
            result = HTTPAPI_OK;
        }
    }
    else
    {
        size_t size = 0;
        result = HTTPAPI_OK;
        for (;;)
        {
            int chunkSize;
            if (readLine(httpHandle, buf, sizeof(buf)) < 0)    // read [length in hex]/r/n
            {
                result = HTTPAPI_READ_DATA_FAILED;
                LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                goto exit;
            }
            if (ParseStringToHexadecimal(buf, &chunkSize) != 1)     // chunkSize is length of next line (/r/n is not counted)
            {
                //Cannot match string, error
                result = HTTPAPI_RECEIVE_RESPONSE_FAILED;
                LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                goto exit;
            }

            if (chunkSize == 0)
            {
                // 0 length means next line is just '\r\n' and end of chunks
                if (readChunk(httpHandle, (char*)buf, 2) < 0
                    || buf[0] != '\r' || buf[1] != '\n') // skip /r/n
                {
                    (void)BUFFER_unbuild(responseContent);

                    result = HTTPAPI_READ_DATA_FAILED;
                    LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                    goto exit;
                }
                break;
            }
            else
            {
                if (responseContent != NULL)
                {
                    if (BUFFER_enlarge(responseContent, chunkSize) != 0)
                    {
                        (void)BUFFER_unbuild(responseContent);

                        result = HTTPAPI_ALLOC_FAILED;
                        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                    }
                    else if (BUFFER_content(responseContent, &receivedContent) != 0)
                    {
                        (void)BUFFER_unbuild(responseContent);

                        result = HTTPAPI_ALLOC_FAILED;
                        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                    }

                    if (readChunk(httpHandle, (char*)receivedContent + size, chunkSize) < 0)
                    {
                        result = HTTPAPI_READ_DATA_FAILED;
                        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                        goto exit;
                    }
                }
                else
                {
                    if (skipN(httpHandle, chunkSize, buf, sizeof(buf)) < 0)
                    {
                        result = HTTPAPI_READ_DATA_FAILED;
                        LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                        goto exit;
                    }
                }

                if (readChunk(httpHandle, (char*)buf, 2) < 0
                    || buf[0] != '\r' || buf[1] != '\n') // skip /r/n
                {
                    result = HTTPAPI_READ_DATA_FAILED;
                    LogError("(result = %s)", ENUM_TO_STRING(HTTPAPI_RESULT, result));
                    goto exit;
                }
                size += chunkSize;
            }
        }

    }

exit:
    if ((handle != NULL) &&
        (handle->is_io_error != 0))
    {
        xio_close(handle->xio_handle, NULL, NULL);
        handle->is_connected = 0;
    }

    return result;
}

HTTPAPI_RESULT HTTPAPI_SetOption(HTTP_HANDLE handle, const char* optionName, const void* value)
{
    HTTPAPI_RESULT result;
    if (
        (handle == NULL) ||
        (optionName == NULL) ||
        (value == NULL)
        )
    {
        result = HTTPAPI_INVALID_ARG;
        LogError("invalid parameter (NULL) passed to HTTPAPI_SetOption");
    }
    else if (strcmp("TrustedCerts", optionName) == 0)
    {
        HTTP_HANDLE_DATA* h = (HTTP_HANDLE_DATA*)handle;
        if (h->certificate)
        {
            free(h->certificate);
        }

        int len = strlen((char*)value);
        h->certificate = (char*)malloc(len + 1);
        if (h->certificate == NULL)
        {
            result = HTTPAPI_ERROR;
            LogError("unable to allocate certificate memory in HTTPAPI_SetOption");
        }
        else
        {
            (void)strcpy(h->certificate, (const char*)value);
            result = HTTPAPI_OK;
        }
    }
    else
    {
        result = HTTPAPI_INVALID_ARG;
        LogError("unknown option %s", optionName);
    }
    return result;
}

HTTPAPI_RESULT HTTPAPI_CloneOption(const char* optionName, const void* value, const void** savedValue)
{
    HTTPAPI_RESULT result;
    if (
        (optionName == NULL) ||
        (value == NULL) ||
        (savedValue == NULL)
        )
    {
        result = HTTPAPI_INVALID_ARG;
        LogError("invalid argument(NULL) passed to HTTPAPI_CloneOption");
    }
    else if (strcmp("TrustedCerts", optionName) == 0)
    {
        size_t certLen = strlen((const char*)value);
        char* tempCert = (char*)malloc(certLen+1);
        if (tempCert == NULL)
        {
            result = HTTPAPI_INVALID_ARG;
            LogError("unable to allocate certificate memory in HTTPAPI_CloneOption");
        }
        else
        {
            (void)strcpy(tempCert, (const char*)value);
            *savedValue = tempCert;
            result = HTTPAPI_OK;
        }
    }
    else
    {
        result = HTTPAPI_INVALID_ARG;
        LogError("unknown option %s", optionName);
    }
    return result;
}