Jeff Smith : crypt32: Make CryptBinaryToStringA fill short base64 buffer correctly.
Module: wine Branch: master Commit: a9e6f9aa71074f96fda9a2475ef1b9009ceeb652 URL: https://source.winehq.org/git/wine.git/?a=commit;h=a9e6f9aa71074f96fda9a2475... Author: Jeff Smith <whydoubt(a)gmail.com> Date: Wed Oct 9 12:53:55 2019 -0500 crypt32: Make CryptBinaryToStringA fill short base64 buffer correctly. Signed-off-by: Jeff Smith <whydoubt(a)gmail.com> Signed-off-by: Alexandre Julliard <julliard(a)winehq.org> --- dlls/crypt32/base64.c | 105 +++++++++++++++++++++++--------------------- dlls/crypt32/tests/base64.c | 2 - 2 files changed, 56 insertions(+), 51 deletions(-) diff --git a/dlls/crypt32/base64.c b/dlls/crypt32/base64.c index acd05ec1a5..ac60c6efbd 100644 --- a/dlls/crypt32/base64.c +++ b/dlls/crypt32/base64.c @@ -93,50 +93,53 @@ static BOOL EncodeBinaryToBinaryA(const BYTE *pbBinary, return ret; } -static LONG encodeBase64A(const BYTE *in_buf, int in_len, LPCSTR sep, +static DWORD stradd(LPSTR ptr, LPCSTR end, LPCSTR s, DWORD slen) +{ + if (ptr + slen > end) + slen = end - ptr; + memcpy(ptr, s, slen); + return slen; +} + +static DWORD encodeBase64A(const BYTE *in_buf, int in_len, LPCSTR sep, char* out_buf, DWORD *out_len) { int div, i; const BYTE *d = in_buf; int bytes = (in_len*8 + 5)/6, pad_bytes = (bytes % 4) ? 4 - (bytes % 4) : 0; - DWORD needed; LPSTR ptr; + LPCSTR end; + char chunk[4]; - TRACE("bytes is %d, pad bytes is %d\n", bytes, pad_bytes); - needed = bytes + pad_bytes; - needed += (needed / 64 + (needed % 64 ? 1 : 0)) * strlen(sep); - needed++; - - if (needed > *out_len) + if (!out_buf) { - *out_len = needed; - return ERROR_INSUFFICIENT_BUFFER; + TRACE("bytes is %d, pad bytes is %d\n", bytes, pad_bytes); + *out_len = bytes + pad_bytes; + *out_len += (*out_len / 64 + (*out_len % 64 ? 1 : 0)) * strlen(sep) + 1; + return 0; } - else - *out_len = needed; /* Three bytes of input give 4 chars of output */ div = in_len / 3; ptr = out_buf; + end = ptr + *out_len; i = 0; - while (div > 0) + while (div > 0 && ptr < end) { if (i && i % 64 == 0) - { - strcpy(ptr, sep); - ptr += strlen(sep); - } + ptr += stradd(ptr, end, sep, strlen(sep)); /* first char is the first 6 bits of the first byte*/ - *ptr++ = b64[ ( d[0] >> 2) & 0x3f ]; + chunk[0] = b64[ ( d[0] >> 2) & 0x3f ]; /* second char is the last 2 bits of the first byte and the first 4 * bits of the second byte */ - *ptr++ = b64[ ((d[0] << 4) & 0x30) | (d[1] >> 4 & 0x0f)]; + chunk[1] = b64[ ((d[0] << 4) & 0x30) | (d[1] >> 4 & 0x0f)]; /* third char is the last 4 bits of the second byte and the first 2 * bits of the third byte */ - *ptr++ = b64[ ((d[1] << 2) & 0x3c) | (d[2] >> 6 & 0x03)]; + chunk[2] = b64[ ((d[1] << 2) & 0x3c) | (d[2] >> 6 & 0x03)]; /* fourth char is the remaining 6 bits of the third byte */ - *ptr++ = b64[ d[2] & 0x3f]; + chunk[3] = b64[ d[2] & 0x3f]; + ptr += stradd(ptr, end, chunk, 4); i += 4; d += 3; div--; @@ -146,31 +149,33 @@ static LONG encodeBase64A(const BYTE *in_buf, int in_len, LPCSTR sep, { case 1: /* first char is the first 6 bits of the first byte*/ - *ptr++ = b64[ ( d[0] >> 2) & 0x3f ]; + chunk[0] = b64[ ( d[0] >> 2) & 0x3f ]; /* second char is the last 2 bits of the first byte and the first 4 * bits of the second byte */ - *ptr++ = b64[ ((d[0] << 4) & 0x30) | (d[1] >> 4 & 0x0f)]; + chunk[1] = b64[ ((d[0] << 4) & 0x30) | (d[1] >> 4 & 0x0f)]; /* third char is the last 4 bits of the second byte padded with * two zeroes */ - *ptr++ = b64[ ((d[1] << 2) & 0x3c) ]; + chunk[2] = b64[ ((d[1] << 2) & 0x3c) ]; /* fourth char is a = to indicate one byte of padding */ - *ptr++ = '='; + chunk[3] = '='; + ptr += stradd(ptr, end, chunk, 4); break; case 2: /* first char is the first 6 bits of the first byte*/ - *ptr++ = b64[ ( d[0] >> 2) & 0x3f ]; + chunk[0] = b64[ ( d[0] >> 2) & 0x3f ]; /* second char is the last 2 bits of the first byte padded with * four zeroes*/ - *ptr++ = b64[ ((d[0] << 4) & 0x30)]; + chunk[1] = b64[ ((d[0] << 4) & 0x30)]; /* third char is = to indicate padding */ - *ptr++ = '='; + chunk[2] = '='; /* fourth char is = to indicate padding */ - *ptr++ = '='; + chunk[3] = '='; + ptr += stradd(ptr, end, chunk, 4); break; } - strcpy(ptr, sep); + ptr += stradd(ptr, end, sep, strlen(sep)); - return ERROR_SUCCESS; + return ptr - out_buf; } static BOOL BinaryToBase64A(const BYTE *pbBinary, @@ -215,26 +220,28 @@ static BOOL BinaryToBase64A(const BYTE *pbBinary, if (pszString) { - if (charsNeeded <= *pcchString) + LPSTR ptr = pszString; + DWORD size = *pcchString; + LPSTR end = ptr + size; + + if (header) { - LPSTR ptr = pszString; - DWORD size = charsNeeded; + ptr += stradd(ptr, end, header, strlen(header)); + ptr += stradd(ptr, end, sep, strlen(sep)); + size = end - ptr; + } + ptr += encodeBase64A(pbBinary, cbBinary, sep, ptr, &size); + if (trailer) + { + ptr += stradd(ptr, end, trailer, strlen(trailer)); + ptr += stradd(ptr, end, sep, strlen(sep)); + } - if (header) - { - strcpy(ptr, header); - ptr += strlen(ptr); - strcpy(ptr, sep); - ptr += strlen(sep); - } - encodeBase64A(pbBinary, cbBinary, sep, ptr, &size); - ptr += size - 1; - if (trailer) - { - strcpy(ptr, trailer); - ptr += strlen(ptr); - strcpy(ptr, sep); - } + if (ptr < end) + *ptr = '\0'; + + if (charsNeeded <= *pcchString) + { *pcchString = charsNeeded - 1; } else diff --git a/dlls/crypt32/tests/base64.c b/dlls/crypt32/tests/base64.c index f2d16735ab..31605fe6b9 100644 --- a/dlls/crypt32/tests/base64.c +++ b/dlls/crypt32/tests/base64.c @@ -137,12 +137,10 @@ static void encodeAndCompareBase64_A(const BYTE *toEncode, DWORD toEncodeLen, ok((!ret && GetLastError() == ERROR_MORE_DATA) || broken(ret) /* XP */, "CryptBinaryToStringA failed %d, error %d.\n", ret, GetLastError()); ok(strLen2 == strLen || broken(strLen2 == strLen - 1), "Expected length %d, got %d\n", strLen, strLen2); -todo_wine { if (header) ok(str[0] == header[0], "Unexpected buffer contents %#x.\n", str[0]); else ok(str[0] == expected[0], "Unexpected buffer contents %#x.\n", str[0]); -} strLen2 = strLen; ret = CryptBinaryToStringA(toEncode, toEncodeLen, format, str, &strLen2); ok(ret, "CryptBinaryToStringA failed: %d\n", GetLastError());
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Alexandre Julliard