Commit 4bf90558 authored by Henri Sivonen's avatar Henri Sivonen
Browse files

Bug 1485592 - Avoid isdigit() in sdp_utils.c. r=drno 

This fixes two problems:
 1) On Windows, isdigit() is locale-dependent.
 2) On platforms where char is signed, sign-extending char to int and passing
    the result to isdigit() was UB when the high bit was set, because
    isdigit() is defined to take a (signed) int with the value space of
    unsigned char or EOF.

MozReview-Commit-ID: D1lY88PEcpc

Differential Revision: https://phabricator.services.mozilla.com/D4316

--HG--
extra : moz-landing-system : lando
parent 16c9e3c5

media/webrtc/signaling/src/sdp/sipcc/sdp_utils.c

+13 −6
Original line number Diff line number Diff line
@@ -15,6 +15,13 @@ 


static const char* logTag = "sdp_utils";



// Actually checks for ASCII only unlike isdigit() on Windows.

// Also avoids UB issues with isdigit() sign extension when

// char is signed.

int sdp_is_ascii_digit(const char c) {

  return '0' <= c && c <= '9';

}



sdp_mca_t *sdp_alloc_mca (uint32_t line) {

    sdp_mca_t           *mca_p;
@@ -155,7 +162,7 @@ verify_sdescriptions_mki (char *buf, char *mkiVal, uint16_t *mkiLen) 


    ptr = buf;

    /* MKI must begin with a digit */

    if (!ptr || (!isdigit((int) *ptr))) {

    if (!ptr || (!sdp_is_ascii_digit(*ptr))) {

        return FALSE;

    }
@@ -166,7 +173,7 @@ verify_sdescriptions_mki (char *buf, char *mkiVal, uint16_t *mkiLen) 
            mkiValBuf[idx] = 0;

            ptr++;

            break;

        } else if ((isdigit((int) *ptr) && (idx < SDP_SRTP_MAX_MKI_SIZE_BYTES-1))) {

        } else if ((sdp_is_ascii_digit(*ptr) && (idx < SDP_SRTP_MAX_MKI_SIZE_BYTES-1))) {

             mkiValBuf[idx++] = *ptr;

        } else {

             return FALSE;
@@ -184,7 +191,7 @@ verify_sdescriptions_mki (char *buf, char *mkiVal, uint16_t *mkiLen) 


    /* verify the mki length (max 3 digits) */

    while (*ptr) {

        if (isdigit((int) *ptr) && (idx < 3)) {

        if (sdp_is_ascii_digit(*ptr) && (idx < 3)) {

            mkiLenBuf[idx++] = *ptr;

        } else {

            return FALSE;
@@ -251,7 +258,7 @@ verify_sdescriptions_lifetime (char *buf) 
                    return FALSE;

                }

            }

        } else if (!isdigit((int) *ptr)) {

        } else if (!sdp_is_ascii_digit(*ptr)) {

                   return FALSE;

        }
@@ -282,13 +289,13 @@ sdp_validate_maxprate(const char *string_parm) 
    tinybool retval = FALSE;



    if (string_parm && (*string_parm)) {

        while (isdigit((int)*string_parm)) {

        while (sdp_is_ascii_digit(*string_parm)) {

            string_parm++;

        }



        if (*string_parm == '.') {

            string_parm++;

            while (isdigit((int)*string_parm)) {

            while (sdp_is_ascii_digit(*string_parm)) {

                string_parm++;

            }

        }