sending a separate ping here as well, for clarity -- Liming, Mike, can one of you please R-b or A-b this specific patch too?
Thanks! Laszlo On 07/02/19 12:28, Laszlo Ersek wrote: > Rewrite Base64Decode() from scratch, due to reasons listed in the second > reference below. > > As first step, redo the interface contract, and replace the current > implementation with a stub that asserts FALSE, then fails. > > Cc: Liming Gao <liming....@intel.com> > Cc: Marvin Häuser <mhaeu...@outlook.de> > Cc: Michael D Kinney <michael.d.kin...@intel.com> > Cc: Philippe Mathieu-Daudé <phi...@redhat.com> > Cc: Zhichao Gao <zhichao....@intel.com> > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1891 > Ref: > c495bd0b-ea4d-7206-8a4f-a7149760d19a@redhat.com">http://mid.mail-archive.com/c495bd0b-ea4d-7206-8a4f-a7149760d19a@redhat.com > Signed-off-by: Laszlo Ersek <ler...@redhat.com> > --- > MdePkg/Include/Library/BaseLib.h | 99 +++++-- > MdePkg/Library/BaseLib/String.c | 285 ++++++-------------- > 2 files changed, 168 insertions(+), 216 deletions(-) > > diff --git a/MdePkg/Include/Library/BaseLib.h > b/MdePkg/Include/Library/BaseLib.h > index ebd7dd274cf4..5ef03e24edb1 100644 > --- a/MdePkg/Include/Library/BaseLib.h > +++ b/MdePkg/Include/Library/BaseLib.h > @@ -2785,31 +2785,94 @@ Base64Encode ( > ); > > /** > - Convert Base64 ascii string to binary data based on RFC4648. > + Decode Base64 ASCII encoded data to 8-bit binary representation, based on > + RFC4648. > > - Produce Null-terminated binary data in the output buffer specified by > Destination and DestinationSize. > - The binary data is produced by converting the Base64 ascii string > specified by Source and SourceLength. > + Decoding occurs according to "Table 1: The Base 64 Alphabet" in RFC4648. > > - @param Source Input ASCII characters > - @param SourceLength Number of ASCII characters > - @param Destination Pointer to output buffer > - @param DestinationSize Caller is responsible for passing in buffer of at > least DestinationSize. > - Set 0 to get the size needed. Set to bytes stored > on return. > + Whitespace is ignored at all positions: > + - 0x09 ('\t') horizontal tab > + - 0x0A ('\n') new line > + - 0x0B ('\v') vertical tab > + - 0x0C ('\f') form feed > + - 0x0D ('\r') carriage return > + - 0x20 (' ') space > > - @retval RETURN_SUCCESS When binary buffer is filled in. > - @retval RETURN_INVALID_PARAMETER If Source is NULL or DestinationSize is > NULL. > - @retval RETURN_INVALID_PARAMETER If SourceLength or DestinationSize is > bigger than (MAX_ADDRESS -(UINTN)Destination ). > - @retval RETURN_INVALID_PARAMETER If there is any invalid character in > input stream. > - @retval RETURN_BUFFER_TOO_SMALL If buffer length is smaller than > required buffer size. > + The minimum amount of required padding (with ASCII 0x3D, '=') is tolerated > + and enforced at the end of the Base64 ASCII encoded data, and only there. > > - **/ > + Other characters outside of the encoding alphabet cause the function to > + reject the Base64 ASCII encoded data. > + > + @param[in] Source Array of CHAR8 elements containing the > Base64 > + ASCII encoding. May be NULL if SourceSize > is > + zero. > + > + @param[in] SourceSize Number of CHAR8 elements in Source. > + > + @param[out] Destination Array of UINT8 elements receiving the > decoded > + 8-bit binary representation. Allocated by > the > + caller. May be NULL if DestinationSize is > + zero on input. If NULL, decoding is > + performed, but the 8-bit binary > + representation is not stored. If non-NULL > and > + the function returns an error, the contents > + of Destination are indeterminate. > + > + @param[in,out] DestinationSize On input, the number of UINT8 elements that > + the caller allocated for Destination. On > + output, if the function returns > + RETURN_SUCCESS or RETURN_BUFFER_TOO_SMALL, > + the number of UINT8 elements that are > + required for decoding the Base64 ASCII > + representation. If the function returns a > + value different from both RETURN_SUCCESS > and > + RETURN_BUFFER_TOO_SMALL, then > DestinationSize > + is indeterminate on output. > + > + @retval RETURN_SUCCESS SourceSize CHAR8 elements at Source have > + been decoded to on-output DestinationSize > + UINT8 elements at Destination. Note that > + RETURN_SUCCESS covers the case when > + DestinationSize is zero on input, and > + Source decodes to zero bytes (due to > + containing at most ignored whitespace). > + > + @retval RETURN_BUFFER_TOO_SMALL The input value of DestinationSize is not > + large enough for decoding SourceSize > CHAR8 > + elements at Source. The required number > of > + UINT8 elements has been stored to > + DestinationSize. > + > + @retval RETURN_INVALID_PARAMETER DestinationSize is NULL. > + > + @retval RETURN_INVALID_PARAMETER Source is NULL, but SourceSize is not > zero. > + > + @retval RETURN_INVALID_PARAMETER Destination is NULL, but DestinationSize > is > + not zero on input. > + > + @retval RETURN_INVALID_PARAMETER Source is non-NULL, and (Source + > + SourceSize) would wrap around > MAX_ADDRESS. > + > + @retval RETURN_INVALID_PARAMETER Destination is non-NULL, and > (Destination + > + DestinationSize) would wrap around > + MAX_ADDRESS, as specified on input. > + > + @retval RETURN_INVALID_PARAMETER None of Source and Destination are NULL, > + and CHAR8[SourceSize] at Source overlaps > + UINT8[DestinationSize] at Destination, as > + specified on input. > + > + @retval RETURN_INVALID_PARAMETER Invalid CHAR8 element encountered in > + Source. > +**/ > RETURN_STATUS > EFIAPI > Base64Decode ( > - IN CONST CHAR8 *Source, > - IN UINTN SourceLength, > - OUT UINT8 *Destination OPTIONAL, > - IN OUT UINTN *DestinationSize > + IN CONST CHAR8 *Source OPTIONAL, > + IN UINTN SourceSize, > + OUT UINT8 *Destination OPTIONAL, > + IN OUT UINTN *DestinationSize > ); > > /** > diff --git a/MdePkg/Library/BaseLib/String.c b/MdePkg/Library/BaseLib/String.c > index 32e189791cb8..f8397035c32a 100644 > --- a/MdePkg/Library/BaseLib/String.c > +++ b/MdePkg/Library/BaseLib/String.c > @@ -1757,45 +1757,10 @@ AsciiStrToUnicodeStr ( > > #endif > > -// > -// The basis for Base64 encoding is RFC 4686 > https://tools.ietf.org/html/rfc4648 > -// > -// RFC 4686 has a number of MAY and SHOULD cases. This implementation > chooses > -// the more restrictive versions for security concerns (see RFC 4686 section > 3.3). > -// > -// A invalid character, if encountered during the decode operation, causes > the data > -// to be rejected. In addition, the '=' padding character is only allowed at > the end > -// of the Base64 encoded string. > -// > -#define BAD_V 99 > - > STATIC CHAR8 EncodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" > "abcdefghijklmnopqrstuvwxyz" > "0123456789+/"; > > -STATIC UINT8 DecodingTable[] = { > - // > - // Valid characters > ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/ > - // Also, set '=' as a zero for decoding > - // 0 , 1, 2, 3, 4, 5, > 6, 7, 8, 9, a, > b, c, d, e, f > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // 0 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // 10 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, 62, BAD_V, BAD_V, BAD_V, 63, // 20 > - 52, 53, 54, 55, 56, 57, 58, 59, 60, > 61, BAD_V, BAD_V, BAD_V, 0, BAD_V, BAD_V, // 30 > - BAD_V, 0, 1, 2, 3, 4, 5, 6, 7, > 8, 9, 10, 11, 12, 13, 14, // 40 > - 15, 16, 17, 18, 19, 20, 21, 22, 23, > 24, 25, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // 50 > - BAD_V, 26, 27, 28, 29, 30, 31, 32, 33, > 34, 35, 36, 37, 38, 39, 40, // 60 > - 41, 42, 43, 44, 45, 46, 47, 48, 49, > 50, 51, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // 70 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // 80 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // 90 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // a0 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // b0 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // c0 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // d0 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, // d0 > - BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, > BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V, BAD_V // f0 > -}; > - > /** > Convert binary data to a Base64 encoded ascii string based on RFC4648. > > @@ -1918,174 +1883,98 @@ Base64Encode ( > } > > /** > - Convert Base64 ascii string to binary data based on RFC4648. > - > - Produce Null-terminated binary data in the output buffer specified by > Destination and DestinationSize. > - The binary data is produced by converting the Base64 ascii string > specified by Source and SourceLength. > - > - @param Source Input ASCII characters > - @param SourceLength Number of ASCII characters > - @param Destination Pointer to output buffer > - @param DestinationSize Caller is responsible for passing in buffer of at > least DestinationSize. > - Set 0 to get the size needed. Set to bytes stored > on return. > - > - @retval RETURN_SUCCESS When binary buffer is filled in. > - @retval RETURN_INVALID_PARAMETER If Source is NULL or DestinationSize is > NULL. > - @retval RETURN_INVALID_PARAMETER If SourceLength or DestinationSize is > bigger than (MAX_ADDRESS -(UINTN)Destination ). > - @retval RETURN_INVALID_PARAMETER If there is any invalid character in > input stream. > - @retval RETURN_BUFFER_TOO_SMALL If buffer length is smaller than > required buffer size. > - **/ > + Decode Base64 ASCII encoded data to 8-bit binary representation, based on > + RFC4648. > + > + Decoding occurs according to "Table 1: The Base 64 Alphabet" in RFC4648. > + > + Whitespace is ignored at all positions: > + - 0x09 ('\t') horizontal tab > + - 0x0A ('\n') new line > + - 0x0B ('\v') vertical tab > + - 0x0C ('\f') form feed > + - 0x0D ('\r') carriage return > + - 0x20 (' ') space > + > + The minimum amount of required padding (with ASCII 0x3D, '=') is tolerated > + and enforced at the end of the Base64 ASCII encoded data, and only there. > + > + Other characters outside of the encoding alphabet cause the function to > + reject the Base64 ASCII encoded data. > + > + @param[in] Source Array of CHAR8 elements containing the > Base64 > + ASCII encoding. May be NULL if SourceSize > is > + zero. > + > + @param[in] SourceSize Number of CHAR8 elements in Source. > + > + @param[out] Destination Array of UINT8 elements receiving the > decoded > + 8-bit binary representation. Allocated by > the > + caller. May be NULL if DestinationSize is > + zero on input. If NULL, decoding is > + performed, but the 8-bit binary > + representation is not stored. If non-NULL > and > + the function returns an error, the contents > + of Destination are indeterminate. > + > + @param[in,out] DestinationSize On input, the number of UINT8 elements that > + the caller allocated for Destination. On > + output, if the function returns > + RETURN_SUCCESS or RETURN_BUFFER_TOO_SMALL, > + the number of UINT8 elements that are > + required for decoding the Base64 ASCII > + representation. If the function returns a > + value different from both RETURN_SUCCESS > and > + RETURN_BUFFER_TOO_SMALL, then > DestinationSize > + is indeterminate on output. > + > + @retval RETURN_SUCCESS SourceSize CHAR8 elements at Source have > + been decoded to on-output DestinationSize > + UINT8 elements at Destination. Note that > + RETURN_SUCCESS covers the case when > + DestinationSize is zero on input, and > + Source decodes to zero bytes (due to > + containing at most ignored whitespace). > + > + @retval RETURN_BUFFER_TOO_SMALL The input value of DestinationSize is not > + large enough for decoding SourceSize > CHAR8 > + elements at Source. The required number > of > + UINT8 elements has been stored to > + DestinationSize. > + > + @retval RETURN_INVALID_PARAMETER DestinationSize is NULL. > + > + @retval RETURN_INVALID_PARAMETER Source is NULL, but SourceSize is not > zero. > + > + @retval RETURN_INVALID_PARAMETER Destination is NULL, but DestinationSize > is > + not zero on input. > + > + @retval RETURN_INVALID_PARAMETER Source is non-NULL, and (Source + > + SourceSize) would wrap around > MAX_ADDRESS. > + > + @retval RETURN_INVALID_PARAMETER Destination is non-NULL, and > (Destination + > + DestinationSize) would wrap around > + MAX_ADDRESS, as specified on input. > + > + @retval RETURN_INVALID_PARAMETER None of Source and Destination are NULL, > + and CHAR8[SourceSize] at Source overlaps > + UINT8[DestinationSize] at Destination, as > + specified on input. > + > + @retval RETURN_INVALID_PARAMETER Invalid CHAR8 element encountered in > + Source. > +**/ > RETURN_STATUS > EFIAPI > Base64Decode ( > - IN CONST CHAR8 *Source, > - IN UINTN SourceLength, > - OUT UINT8 *Destination OPTIONAL, > - IN OUT UINTN *DestinationSize > + IN CONST CHAR8 *Source OPTIONAL, > + IN UINTN SourceSize, > + OUT UINT8 *Destination OPTIONAL, > + IN OUT UINTN *DestinationSize > ) > { > - > - UINT32 Value; > - CHAR8 Chr; > - INTN BufferSize; > - UINTN SourceIndex; > - UINTN DestinationIndex; > - UINTN Index; > - UINTN ActualSourceLength; > - > - // > - // Check pointers are not NULL > - // > - if ((Source == NULL) || (DestinationSize == NULL)) { > - return RETURN_INVALID_PARAMETER; > - } > - > - // > - // Check if SourceLength or DestinationSize is valid > - // > - if ((SourceLength >= (MAX_ADDRESS - (UINTN)Source)) || (*DestinationSize > >= (MAX_ADDRESS - (UINTN)Destination))){ > - return RETURN_INVALID_PARAMETER; > - } > - > - ActualSourceLength = 0; > - BufferSize = 0; > - > - // > - // Determine the actual number of valid characters in the string. > - // All invalid characters except selected white space characters, > - // will cause the Base64 string to be rejected. White space to allow > - // properly formatted XML will be ignored. > - // > - // See section 3.3 of RFC 4648. > - // > - for (SourceIndex = 0; SourceIndex < SourceLength; SourceIndex++) { > - > - // > - // '=' is part of the quantum > - // > - if (Source[SourceIndex] == '=') { > - ActualSourceLength++; > - BufferSize--; > - > - // > - // Only two '=' characters can be valid. > - // > - if (BufferSize < -2) { > - return RETURN_INVALID_PARAMETER; > - } > - } > - else { > - Chr = Source[SourceIndex]; > - if (BAD_V != DecodingTable[(UINT8) Chr]) { > - > - // > - // The '=' characters are only valid at the end, so any > - // valid character after an '=', will be flagged as an error. > - // > - if (BufferSize < 0) { > - return RETURN_INVALID_PARAMETER; > - } > - ActualSourceLength++; > - } > - else { > - > - // > - // The reset of the decoder will ignore all invalid characters > allowed here. > - // Ignoring selected white space is useful. In this case, the > decoder will > - // ignore ' ', '\t', '\n', and '\r'. > - // > - if ((Chr != ' ') &&(Chr != '\t') &&(Chr != '\n') &&(Chr != '\r')) { > - return RETURN_INVALID_PARAMETER; > - } > - } > - } > - } > - > - // > - // The Base64 character string must be a multiple of 4 character quantums. > - // > - if (ActualSourceLength % 4 != 0) { > - return RETURN_INVALID_PARAMETER; > - } > - > - BufferSize += ActualSourceLength / 4 * 3; > - if (BufferSize < 0) { > - return RETURN_INVALID_PARAMETER; > - } > - > - // > - // BufferSize is >= 0 > - // > - if ((Destination == NULL) || (*DestinationSize < (UINTN) BufferSize)) { > - *DestinationSize = BufferSize; > - return RETURN_BUFFER_TOO_SMALL; > - } > - > - // > - // If no decodable characters, return a size of zero. RFC 4686 test vector > 1. > - // > - if (ActualSourceLength == 0) { > - *DestinationSize = 0; > - return RETURN_SUCCESS; > - } > - > - // > - // Input data is verified to be a multiple of 4 valid charcters. Process > four > - // characters at a time. Uncounted (ie. invalid) characters will be > ignored. > - // > - for (SourceIndex = 0, DestinationIndex = 0; (SourceIndex < SourceLength) > && (DestinationIndex < *DestinationSize); ) { > - Value = 0; > - > - // > - // Get 24 bits of data from 4 input characters, each character > representing 6 bits > - // > - for (Index = 0; Index < 4; Index++) { > - do { > - Chr = DecodingTable[(UINT8) Source[SourceIndex++]]; > - } while (Chr == BAD_V); > - Value <<= 6; > - Value |= (UINT32)Chr; > - } > - > - // > - // Store 3 bytes of binary data (24 bits) > - // > - *Destination++ = (UINT8) (Value >> 16); > - DestinationIndex++; > - > - // > - // Due to the '=' special cases for the two bytes at the end, > - // we have to check the length and not store the padding data > - // > - if (DestinationIndex++ < *DestinationSize) { > - *Destination++ = (UINT8) (Value >> 8); > - } > - if (DestinationIndex++ < *DestinationSize) { > - *Destination++ = (UINT8) Value; > - } > - } > - > - return RETURN_SUCCESS; > + ASSERT (FALSE); > + return RETURN_INVALID_PARAMETER; > } > > /** > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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