Delphi Firemonkey LockBox3 AES-CBC, PC and Android result are different?

-1

I need a AES library for devolop Firemonkey Moblie App. I tested ElAES and LockBox3, everything works fine complie to PC, But on FMX Android both library return wrong ciphertext.

Test Data (AES128CBC PKCS5Padding):

plainText: 'plainText'  - edtPlaintext.Text

key: '0000000000000000' - edtKey.Text

IV: '0000000000000000' - edtIV.Text

cipherText:  hex - 'DD0A2A20616162697B8B4DF53483F1D2',

             base64 - '3QoqIGFhYml7i031NIPx0g=='

Test Code:

This is test code reley on LockBox3, related: https://github.com/TurboPack/LockBox3, function 'EncryptMemory' return unfixed ciphertext each time on Android, something need to notice?

uses uTPLb_Codec, uTPLb_CryptographicLibrary, uTPLb_Constants, uTPLb_StreamUtils;



type

  TCustomPadder = class(TObject)

  private

    FIV: TBytes;

  public

    constructor Create(const AIV: TBytes);

    procedure OnSetIV(Value: TMemoryStream);

  end;



constructor TCustomPadder.Create(const AIV: TBytes);

begin

  FIV := AIV

end;



procedure TCustomPadder.OnSetIV(Value: TMemoryStream);

begin

  Value.Size := Length(FIV);

  Value.Position := 0;

  Value.WriteBuffer(FIV, Length(FIV))

end;



function NewCodec(key: TBytes): TCodec;

var

  codec: TCodec;

  cryptographicLibrary: TCryptographicLibrary;

  keyStream: TStream;

  padder: TCustomPadder;

begin

  cryptographicLibrary := TCryptographicLibrary.Create(nil);

  // basic

  codec := TCodec.Create(nil);

  codec.BlockCipherId := Format(AES_ProgId, [128]);

  codec.ChainModeId := CBC_ProgId;

  codec.CryptoLibrary := cryptographicLibrary;

  codec.StreamCipherId := BlockCipher_ProgId;

  // extend

  padder := TCustomPadder.Create(bytesof('0000000000000000'));

  keyStream := TMemoryStream.Create;

  keyStream.WriteBuffer(key, Length(key));

  keyStream.Position := 0;

  codec.OnSetIV := padder.OnSetIV;

  codec.InitFromStream(keyStream);

  result := codec;

end;



function PKCS5Padding(ciphertext: string; blocksize: integer): string;

var

  builder: TStringBuilder;

  padding: integer;

  i: integer;

begin

  builder := TStringBuilder.Create(ciphertext);

  padding := blocksize - (builder.Length mod blocksize);

  for i := 1 to padding do

  begin

    builder.Append(Char(padding));

  end;

  result := builder.ToString;

  builder.DisposeOf;

end;



function BytesToHexStr(bytes: TBytes): string;

var

  i: integer;

begin

  result := '';

  for i := 0 to Length(bytes) - 1 do

    result := result + bytes[i].ToHexString(2);

end;



procedure TformAEST.btnEncryptClick(Sender: TObject);

var

  codec: TCodec;

  plainBytes, cipherBytes: TBytes;

  cipherMemory: TStream;

  cipherBytesLen: integer;

begin



  cipherMemory := TMemoryStream.Create;



  plainBytes := bytesof(PKCS5Padding(edtPlaintext.Text, 16));



  codec := NewCodec(bytesof(edtKey.Text));

  codec.Begin_EncryptMemory(cipherMemory);

  codec.EncryptMemory(plainBytes, Length(plainBytes));

  codec.End_EncryptMemory;



  cipherMemory.Position := 8;

  cipherBytesLen := cipherMemory.Size - 8;

  SetLength(cipherBytes, cipherBytesLen);

  cipherMemory.ReadBuffer(cipherBytes, cipherBytesLen);

  edtCiphertext.Text := BytesToHexStr(cipherBytes);

end;

asked Jan 1 at 13:52

86153

Consider accepting answers that are helpful and reviewing previous answers an accepting is appropriate. 1, See reputation faq Voting up a question or answer signals to the rest of the community that a post is interesting, well-researched, and useful.

– zaph
Jan 1 at 18:04

add a comment |

-1

I need a AES library for devolop Firemonkey Moblie App. I tested ElAES and LockBox3, everything works fine complie to PC, But on FMX Android both library return wrong ciphertext.

Test Data (AES128CBC PKCS5Padding):

plainText: 'plainText'  - edtPlaintext.Text

key: '0000000000000000' - edtKey.Text

IV: '0000000000000000' - edtIV.Text

cipherText:  hex - 'DD0A2A20616162697B8B4DF53483F1D2',

             base64 - '3QoqIGFhYml7i031NIPx0g=='

Test Code:

This is test code reley on LockBox3, related: https://github.com/TurboPack/LockBox3, function 'EncryptMemory' return unfixed ciphertext each time on Android, something need to notice?

uses uTPLb_Codec, uTPLb_CryptographicLibrary, uTPLb_Constants, uTPLb_StreamUtils;



type

  TCustomPadder = class(TObject)

  private

    FIV: TBytes;

  public

    constructor Create(const AIV: TBytes);

    procedure OnSetIV(Value: TMemoryStream);

  end;



constructor TCustomPadder.Create(const AIV: TBytes);

begin

  FIV := AIV

end;



procedure TCustomPadder.OnSetIV(Value: TMemoryStream);

begin

  Value.Size := Length(FIV);

  Value.Position := 0;

  Value.WriteBuffer(FIV, Length(FIV))

end;



function NewCodec(key: TBytes): TCodec;

var

  codec: TCodec;

  cryptographicLibrary: TCryptographicLibrary;

  keyStream: TStream;

  padder: TCustomPadder;

begin

  cryptographicLibrary := TCryptographicLibrary.Create(nil);

  // basic

  codec := TCodec.Create(nil);

  codec.BlockCipherId := Format(AES_ProgId, [128]);

  codec.ChainModeId := CBC_ProgId;

  codec.CryptoLibrary := cryptographicLibrary;

  codec.StreamCipherId := BlockCipher_ProgId;

  // extend

  padder := TCustomPadder.Create(bytesof('0000000000000000'));

  keyStream := TMemoryStream.Create;

  keyStream.WriteBuffer(key, Length(key));

  keyStream.Position := 0;

  codec.OnSetIV := padder.OnSetIV;

  codec.InitFromStream(keyStream);

  result := codec;

end;



function PKCS5Padding(ciphertext: string; blocksize: integer): string;

var

  builder: TStringBuilder;

  padding: integer;

  i: integer;

begin

  builder := TStringBuilder.Create(ciphertext);

  padding := blocksize - (builder.Length mod blocksize);

  for i := 1 to padding do

  begin

    builder.Append(Char(padding));

  end;

  result := builder.ToString;

  builder.DisposeOf;

end;



function BytesToHexStr(bytes: TBytes): string;

var

  i: integer;

begin

  result := '';

  for i := 0 to Length(bytes) - 1 do

    result := result + bytes[i].ToHexString(2);

end;



procedure TformAEST.btnEncryptClick(Sender: TObject);

var

  codec: TCodec;

  plainBytes, cipherBytes: TBytes;

  cipherMemory: TStream;

  cipherBytesLen: integer;

begin



  cipherMemory := TMemoryStream.Create;



  plainBytes := bytesof(PKCS5Padding(edtPlaintext.Text, 16));



  codec := NewCodec(bytesof(edtKey.Text));

  codec.Begin_EncryptMemory(cipherMemory);

  codec.EncryptMemory(plainBytes, Length(plainBytes));

  codec.End_EncryptMemory;



  cipherMemory.Position := 8;

  cipherBytesLen := cipherMemory.Size - 8;

  SetLength(cipherBytes, cipherBytesLen);

  cipherMemory.ReadBuffer(cipherBytes, cipherBytesLen);

  edtCiphertext.Text := BytesToHexStr(cipherBytes);

end;

asked Jan 1 at 13:52

86153

Consider accepting answers that are helpful and reviewing previous answers an accepting is appropriate. 1, See reputation faq Voting up a question or answer signals to the rest of the community that a post is interesting, well-researched, and useful.

– zaph
Jan 1 at 18:04

add a comment |

-1

I need a AES library for devolop Firemonkey Moblie App. I tested ElAES and LockBox3, everything works fine complie to PC, But on FMX Android both library return wrong ciphertext.

Test Data (AES128CBC PKCS5Padding):

plainText: 'plainText'  - edtPlaintext.Text

key: '0000000000000000' - edtKey.Text

IV: '0000000000000000' - edtIV.Text

cipherText:  hex - 'DD0A2A20616162697B8B4DF53483F1D2',

             base64 - '3QoqIGFhYml7i031NIPx0g=='

Test Code:

This is test code reley on LockBox3, related: https://github.com/TurboPack/LockBox3, function 'EncryptMemory' return unfixed ciphertext each time on Android, something need to notice?

uses uTPLb_Codec, uTPLb_CryptographicLibrary, uTPLb_Constants, uTPLb_StreamUtils;



type

  TCustomPadder = class(TObject)

  private

    FIV: TBytes;

  public

    constructor Create(const AIV: TBytes);

    procedure OnSetIV(Value: TMemoryStream);

  end;



constructor TCustomPadder.Create(const AIV: TBytes);

begin

  FIV := AIV

end;



procedure TCustomPadder.OnSetIV(Value: TMemoryStream);

begin

  Value.Size := Length(FIV);

  Value.Position := 0;

  Value.WriteBuffer(FIV, Length(FIV))

end;



function NewCodec(key: TBytes): TCodec;

var

  codec: TCodec;

  cryptographicLibrary: TCryptographicLibrary;

  keyStream: TStream;

  padder: TCustomPadder;

begin

  cryptographicLibrary := TCryptographicLibrary.Create(nil);

  // basic

  codec := TCodec.Create(nil);

  codec.BlockCipherId := Format(AES_ProgId, [128]);

  codec.ChainModeId := CBC_ProgId;

  codec.CryptoLibrary := cryptographicLibrary;

  codec.StreamCipherId := BlockCipher_ProgId;

  // extend

  padder := TCustomPadder.Create(bytesof('0000000000000000'));

  keyStream := TMemoryStream.Create;

  keyStream.WriteBuffer(key, Length(key));

  keyStream.Position := 0;

  codec.OnSetIV := padder.OnSetIV;

  codec.InitFromStream(keyStream);

  result := codec;

end;



function PKCS5Padding(ciphertext: string; blocksize: integer): string;

var

  builder: TStringBuilder;

  padding: integer;

  i: integer;

begin

  builder := TStringBuilder.Create(ciphertext);

  padding := blocksize - (builder.Length mod blocksize);

  for i := 1 to padding do

  begin

    builder.Append(Char(padding));

  end;

  result := builder.ToString;

  builder.DisposeOf;

end;



function BytesToHexStr(bytes: TBytes): string;

var

  i: integer;

begin

  result := '';

  for i := 0 to Length(bytes) - 1 do

    result := result + bytes[i].ToHexString(2);

end;



procedure TformAEST.btnEncryptClick(Sender: TObject);

var

  codec: TCodec;

  plainBytes, cipherBytes: TBytes;

  cipherMemory: TStream;

  cipherBytesLen: integer;

begin



  cipherMemory := TMemoryStream.Create;



  plainBytes := bytesof(PKCS5Padding(edtPlaintext.Text, 16));



  codec := NewCodec(bytesof(edtKey.Text));

  codec.Begin_EncryptMemory(cipherMemory);

  codec.EncryptMemory(plainBytes, Length(plainBytes));

  codec.End_EncryptMemory;



  cipherMemory.Position := 8;

  cipherBytesLen := cipherMemory.Size - 8;

  SetLength(cipherBytes, cipherBytesLen);

  cipherMemory.ReadBuffer(cipherBytes, cipherBytesLen);

  edtCiphertext.Text := BytesToHexStr(cipherBytes);

end;

asked Jan 1 at 13:52

86153

I need a AES library for devolop Firemonkey Moblie App. I tested ElAES and LockBox3, everything works fine complie to PC, But on FMX Android both library return wrong ciphertext.

Test Data (AES128CBC PKCS5Padding):

plainText: 'plainText'  - edtPlaintext.Text

key: '0000000000000000' - edtKey.Text

IV: '0000000000000000' - edtIV.Text

cipherText:  hex - 'DD0A2A20616162697B8B4DF53483F1D2',

             base64 - '3QoqIGFhYml7i031NIPx0g=='

Test Code:

This is test code reley on LockBox3, related: https://github.com/TurboPack/LockBox3, function 'EncryptMemory' return unfixed ciphertext each time on Android, something need to notice?

uses uTPLb_Codec, uTPLb_CryptographicLibrary, uTPLb_Constants, uTPLb_StreamUtils;



type

  TCustomPadder = class(TObject)

  private

    FIV: TBytes;

  public

    constructor Create(const AIV: TBytes);

    procedure OnSetIV(Value: TMemoryStream);

  end;



constructor TCustomPadder.Create(const AIV: TBytes);

begin

  FIV := AIV

end;



procedure TCustomPadder.OnSetIV(Value: TMemoryStream);

begin

  Value.Size := Length(FIV);

  Value.Position := 0;

  Value.WriteBuffer(FIV, Length(FIV))

end;



function NewCodec(key: TBytes): TCodec;

var

  codec: TCodec;

  cryptographicLibrary: TCryptographicLibrary;

  keyStream: TStream;

  padder: TCustomPadder;

begin

  cryptographicLibrary := TCryptographicLibrary.Create(nil);

  // basic

  codec := TCodec.Create(nil);

  codec.BlockCipherId := Format(AES_ProgId, [128]);

  codec.ChainModeId := CBC_ProgId;

  codec.CryptoLibrary := cryptographicLibrary;

  codec.StreamCipherId := BlockCipher_ProgId;

  // extend

  padder := TCustomPadder.Create(bytesof('0000000000000000'));

  keyStream := TMemoryStream.Create;

  keyStream.WriteBuffer(key, Length(key));

  keyStream.Position := 0;

  codec.OnSetIV := padder.OnSetIV;

  codec.InitFromStream(keyStream);

  result := codec;

end;



function PKCS5Padding(ciphertext: string; blocksize: integer): string;

var

  builder: TStringBuilder;

  padding: integer;

  i: integer;

begin

  builder := TStringBuilder.Create(ciphertext);

  padding := blocksize - (builder.Length mod blocksize);

  for i := 1 to padding do

  begin

    builder.Append(Char(padding));

  end;

  result := builder.ToString;

  builder.DisposeOf;

end;



function BytesToHexStr(bytes: TBytes): string;

var

  i: integer;

begin

  result := '';

  for i := 0 to Length(bytes) - 1 do

    result := result + bytes[i].ToHexString(2);

end;



procedure TformAEST.btnEncryptClick(Sender: TObject);

var

  codec: TCodec;

  plainBytes, cipherBytes: TBytes;

  cipherMemory: TStream;

  cipherBytesLen: integer;

begin



  cipherMemory := TMemoryStream.Create;



  plainBytes := bytesof(PKCS5Padding(edtPlaintext.Text, 16));



  codec := NewCodec(bytesof(edtKey.Text));

  codec.Begin_EncryptMemory(cipherMemory);

  codec.EncryptMemory(plainBytes, Length(plainBytes));

  codec.End_EncryptMemory;



  cipherMemory.Position := 8;

  cipherBytesLen := cipherMemory.Size - 8;

  SetLength(cipherBytes, cipherBytesLen);

  cipherMemory.ReadBuffer(cipherBytes, cipherBytesLen);

  edtCiphertext.Text := BytesToHexStr(cipherBytes);

end;

firemonkey delphi-xe lockbox-3

asked Jan 1 at 13:52

86153

asked Jan 1 at 13:52

86153

asked Jan 1 at 13:52

86153

asked Jan 1 at 13:52

86153

asked Jan 1 at 13:52

86153

Consider accepting answers that are helpful and reviewing previous answers an accepting is appropriate. 1, See reputation faq Voting up a question or answer signals to the rest of the community that a post is interesting, well-researched, and useful.

– zaph
Jan 1 at 18:04

add a comment |

Consider accepting answers that are helpful and reviewing previous answers an accepting is appropriate. 1, See reputation faq Voting up a question or answer signals to the rest of the community that a post is interesting, well-researched, and useful.

– zaph
Jan 1 at 18:04

Consider accepting answers that are helpful and reviewing previous answers an accepting is appropriate. 1, See reputation faq Voting up a question or answer signals to the rest of the community that a post is interesting, well-researched, and useful.

– zaph
Jan 1 at 18:04

add a comment |

1 Answer
1

active

oldest

votes

Encryption and decryption operate on raw bytes, not on characters.

When encrypting Unicode strings, especially across platforms, you have to encode the characters to bytes using a consistent byte encoding before then encrypting those bytes.

And when decrypting Unicode strings, make sure to use that same byte encoding when converting the decrypted bytes back into characters.

In your code, you are using BytesOf() to encode Unicode characters to bytes. Internally, BytesOf() uses TEncoding.Default as the encoding, which is TEncoding.ANSI on Windows PCs but is TEncoding.UTF8 on other platforms. So, if your input strings contain any non-ASCII characters, you will end up with different results.

I suggest replacing BytesOf() with TEncoding.UTF8.GetBytes() on all platforms:

plainBytes := TEncoding.UTF8.GetBytes(PKCS5Padding(edtPlaintext.Text, 16));



codec := NewCodec(TEncoding.UTF8.GetBytes(edtKey.Text));

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

Thanks answer, from Debugger/Output: key/IV:30303030303030303030303030303030 plainBytes: 706C61696E5465787407070707070707, the same two platform, seems not this reason.

– 86153
Jan 2 at 1:16

@86153 it is very unlikely that 2 different encryption libraries would both fail on mobile, it is more likely that you are doing sonething differently in how you use the libraries across platforms. You will have to continue debugging to see where differences between platforms actually occur at each step.

– Remy Lebeau
Jan 2 at 7:31

@86153 And FYI, on a side note, you should NOT be applying PKCS5 padding to the string you are encrypting, you should be applying the padding to plainBytes before giving it to the library. Again, encryption operates on bytes, and the blocksize applies to the bytes being encrypted, not to the characters used to produce those bytes, so the padding needs to be added to the end of the actual bytes, not the string. This is a subtle but important thing to get right.

– Remy Lebeau
Jan 2 at 7:32

Thanks Remy, finally I use DCPcrypt2, it's work on android. Related Quetion: stackoverflow.com/questions/43523262/…

– 86153
Jan 2 at 8:18

@86153 that other question is not the same issue as this one. The other question used string buffers for the bytes, and suffered from indexing issues across platforms. This question does not do that.

– Remy Lebeau
Jan 2 at 16:37

add a comment |

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1 Answer
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1 Answer
1

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Encryption and decryption operate on raw bytes, not on characters.

When encrypting Unicode strings, especially across platforms, you have to encode the characters to bytes using a consistent byte encoding before then encrypting those bytes.

And when decrypting Unicode strings, make sure to use that same byte encoding when converting the decrypted bytes back into characters.

I suggest replacing BytesOf() with TEncoding.UTF8.GetBytes() on all platforms:

plainBytes := TEncoding.UTF8.GetBytes(PKCS5Padding(edtPlaintext.Text, 16));



codec := NewCodec(TEncoding.UTF8.GetBytes(edtKey.Text));

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

Thanks answer, from Debugger/Output: key/IV:30303030303030303030303030303030 plainBytes: 706C61696E5465787407070707070707, the same two platform, seems not this reason.

– 86153
Jan 2 at 1:16

@86153 it is very unlikely that 2 different encryption libraries would both fail on mobile, it is more likely that you are doing sonething differently in how you use the libraries across platforms. You will have to continue debugging to see where differences between platforms actually occur at each step.

– Remy Lebeau
Jan 2 at 7:31

@86153 And FYI, on a side note, you should NOT be applying PKCS5 padding to the string you are encrypting, you should be applying the padding to plainBytes before giving it to the library. Again, encryption operates on bytes, and the blocksize applies to the bytes being encrypted, not to the characters used to produce those bytes, so the padding needs to be added to the end of the actual bytes, not the string. This is a subtle but important thing to get right.

– Remy Lebeau
Jan 2 at 7:32

Thanks Remy, finally I use DCPcrypt2, it's work on android. Related Quetion: stackoverflow.com/questions/43523262/…

– 86153
Jan 2 at 8:18

@86153 that other question is not the same issue as this one. The other question used string buffers for the bytes, and suffered from indexing issues across platforms. This question does not do that.

– Remy Lebeau
Jan 2 at 16:37

add a comment |

Encryption and decryption operate on raw bytes, not on characters.

When encrypting Unicode strings, especially across platforms, you have to encode the characters to bytes using a consistent byte encoding before then encrypting those bytes.

And when decrypting Unicode strings, make sure to use that same byte encoding when converting the decrypted bytes back into characters.

I suggest replacing BytesOf() with TEncoding.UTF8.GetBytes() on all platforms:

plainBytes := TEncoding.UTF8.GetBytes(PKCS5Padding(edtPlaintext.Text, 16));



codec := NewCodec(TEncoding.UTF8.GetBytes(edtKey.Text));

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

Thanks answer, from Debugger/Output: key/IV:30303030303030303030303030303030 plainBytes: 706C61696E5465787407070707070707, the same two platform, seems not this reason.

– 86153
Jan 2 at 1:16

@86153 it is very unlikely that 2 different encryption libraries would both fail on mobile, it is more likely that you are doing sonething differently in how you use the libraries across platforms. You will have to continue debugging to see where differences between platforms actually occur at each step.

– Remy Lebeau
Jan 2 at 7:31

@86153 And FYI, on a side note, you should NOT be applying PKCS5 padding to the string you are encrypting, you should be applying the padding to plainBytes before giving it to the library. Again, encryption operates on bytes, and the blocksize applies to the bytes being encrypted, not to the characters used to produce those bytes, so the padding needs to be added to the end of the actual bytes, not the string. This is a subtle but important thing to get right.

– Remy Lebeau
Jan 2 at 7:32

Thanks Remy, finally I use DCPcrypt2, it's work on android. Related Quetion: stackoverflow.com/questions/43523262/…

– 86153
Jan 2 at 8:18

@86153 that other question is not the same issue as this one. The other question used string buffers for the bytes, and suffered from indexing issues across platforms. This question does not do that.

– Remy Lebeau
Jan 2 at 16:37

add a comment |

Encryption and decryption operate on raw bytes, not on characters.

When encrypting Unicode strings, especially across platforms, you have to encode the characters to bytes using a consistent byte encoding before then encrypting those bytes.

And when decrypting Unicode strings, make sure to use that same byte encoding when converting the decrypted bytes back into characters.

I suggest replacing BytesOf() with TEncoding.UTF8.GetBytes() on all platforms:

plainBytes := TEncoding.UTF8.GetBytes(PKCS5Padding(edtPlaintext.Text, 16));



codec := NewCodec(TEncoding.UTF8.GetBytes(edtKey.Text));

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

Encryption and decryption operate on raw bytes, not on characters.

When encrypting Unicode strings, especially across platforms, you have to encode the characters to bytes using a consistent byte encoding before then encrypting those bytes.

And when decrypting Unicode strings, make sure to use that same byte encoding when converting the decrypted bytes back into characters.

I suggest replacing BytesOf() with TEncoding.UTF8.GetBytes() on all platforms:

plainBytes := TEncoding.UTF8.GetBytes(PKCS5Padding(edtPlaintext.Text, 16));



codec := NewCodec(TEncoding.UTF8.GetBytes(edtKey.Text));

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

answered Jan 1 at 16:50

Remy Lebeau

339k19263458

Thanks answer, from Debugger/Output: key/IV:30303030303030303030303030303030 plainBytes: 706C61696E5465787407070707070707, the same two platform, seems not this reason.

– 86153
Jan 2 at 1:16

@86153 it is very unlikely that 2 different encryption libraries would both fail on mobile, it is more likely that you are doing sonething differently in how you use the libraries across platforms. You will have to continue debugging to see where differences between platforms actually occur at each step.

– Remy Lebeau
Jan 2 at 7:31

@86153 And FYI, on a side note, you should NOT be applying PKCS5 padding to the string you are encrypting, you should be applying the padding to plainBytes before giving it to the library. Again, encryption operates on bytes, and the blocksize applies to the bytes being encrypted, not to the characters used to produce those bytes, so the padding needs to be added to the end of the actual bytes, not the string. This is a subtle but important thing to get right.

– Remy Lebeau
Jan 2 at 7:32

Thanks Remy, finally I use DCPcrypt2, it's work on android. Related Quetion: stackoverflow.com/questions/43523262/…

– 86153
Jan 2 at 8:18

@86153 that other question is not the same issue as this one. The other question used string buffers for the bytes, and suffered from indexing issues across platforms. This question does not do that.

– Remy Lebeau
Jan 2 at 16:37

add a comment |

Thanks answer, from Debugger/Output: key/IV:30303030303030303030303030303030 plainBytes: 706C61696E5465787407070707070707, the same two platform, seems not this reason.

– 86153
Jan 2 at 1:16

@86153 it is very unlikely that 2 different encryption libraries would both fail on mobile, it is more likely that you are doing sonething differently in how you use the libraries across platforms. You will have to continue debugging to see where differences between platforms actually occur at each step.

– Remy Lebeau
Jan 2 at 7:31

@86153 And FYI, on a side note, you should NOT be applying PKCS5 padding to the string you are encrypting, you should be applying the padding to plainBytes before giving it to the library. Again, encryption operates on bytes, and the blocksize applies to the bytes being encrypted, not to the characters used to produce those bytes, so the padding needs to be added to the end of the actual bytes, not the string. This is a subtle but important thing to get right.

– Remy Lebeau
Jan 2 at 7:32

Thanks Remy, finally I use DCPcrypt2, it's work on android. Related Quetion: stackoverflow.com/questions/43523262/…

– 86153
Jan 2 at 8:18

@86153 that other question is not the same issue as this one. The other question used string buffers for the bytes, and suffered from indexing issues across platforms. This question does not do that.

– Remy Lebeau
Jan 2 at 16:37

Thanks answer, from Debugger/Output: key/IV:30303030303030303030303030303030 plainBytes: 706C61696E5465787407070707070707, the same two platform, seems not this reason.

– 86153
Jan 2 at 1:16

@86153 it is very unlikely that 2 different encryption libraries would both fail on mobile, it is more likely that you are doing sonething differently in how you use the libraries across platforms. You will have to continue debugging to see where differences between platforms actually occur at each step.

– Remy Lebeau
Jan 2 at 7:31

@86153 And FYI, on a side note, you should NOT be applying PKCS5 padding to the string you are encrypting, you should be applying the padding to plainBytes before giving it to the library. Again, encryption operates on bytes, and the blocksize applies to the bytes being encrypted, not to the characters used to produce those bytes, so the padding needs to be added to the end of the actual bytes, not the string. This is a subtle but important thing to get right.

– Remy Lebeau
Jan 2 at 7:32

Thanks Remy, finally I use DCPcrypt2, it's work on android. Related Quetion: stackoverflow.com/questions/43523262/…

– 86153
Jan 2 at 8:18

@86153 that other question is not the same issue as this one. The other question used string buffers for the bytes, and suffered from indexing issues across platforms. This question does not do that.

– Remy Lebeau
Jan 2 at 16:37

add a comment |

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