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在使用openSSL库时,我遇到了EVP_EncryptFinal_ex问题。 具体而言,它每次都会因致命错误./crypto/evp/evp_enc.c(348) OpenSSL internal error, assertion failed: b <= sizeof ctx -> buf
而失败,而不依赖于算法(aes或des)。在EVP_EncryptFinal_ex期间openssl错误“断言失败”,delphi
这是我的代码。尽可能简化。
procedure AESTest;
var
key : TBytes;
keyLen : Integer;
dataIn : string;
dataOut : TBytes;
inLen, outLen, resLen : integer;
// Context of an algorithm pointer
e_ctx : Pointer;
begin
// 256 bit key
keyLen := 32;
setlength(key, KeyLen);
RAND_bytes(@(key[0]), KeyLen);
// Input data to encrypt
dataIn := 'Simple data of 29 bits length';
inLen := length(dataIn);
// Init ctx
e_ctx := EVP_CIPHER_CTX_new();
EVP_CIPHER_CTX_init(e_ctx);
EVP_EncryptInit_ex(e_ctx, EVP_aes_256_cbc, nil, @key[0], nil);
// Prepare ouput buf in order to openSSL docs
outLen := inLen + EVP_CIPHER_CTX_block_size(e_ctx) - 1;
setlength(dataOut, outLen);
EVP_EncryptUpdate(e_ctx, @dataOut[0], outLen, @dataIn[1], inLen);
EVP_EncryptFinal_ex(e_ctx, @dataOut[outLen], resLen);
outLen := outLen + resLen;
setlength(dataOut, outLen);
// ... here goes decryption part but it does not matter now
end;
只是要精确,采用进口:
const
LIB_DLL_NAME = 'libeay32.dll';
type
PEVP_CIPHER_CTX : Pointer;
PEVP_CIPHER : Pointer;
function EVP_CIPHER_CTX_new : PEVP_CIPHER_CTX; cdecl; external LIB_DLL_NAME;
procedure EVP_CIPHER_CTX_init(a: PEVP_CIPHER_CTX); cdecl; external LIB_DLL_NAME;
function EVP_aes_256_cbc : PEVP_CIPHER_CTX; cdecl; external LIB_DLL_NAME;
function RAND_bytes(Arr : PByte; ArrLen : integer) : integer; cdecl; external LIB_DLL_NAME;
function EVP_CIPHER_CTX_block_size(ctx: PEVP_CIPHER_CTX): integer; cdecl; external LIB_DLL_NAME;
function EVP_EncryptInit_ex(ctx: PEVP_CIPHER_CTX; cipher_type: PEVP_CIPHER; Engine : Pointer; key: PByte; iv: PByte): integer; cdecl; external LIB_DLL_NAME;
function EVP_EncryptUpdate(ctx: PEVP_CIPHER_CTX; data_out: PByte; var outl: integer; data_in: PByte; inl: integer): integer; cdecl; external LIB_DLL_NAME;
function EVP_EncryptFinal_ex(ctx: PEVP_CIPHER_CTX; data_out: PByte; var outl: integer): integer; external LIB_DLL_NAME;
其实我试图读取源代码(evp_enc.c),发现断言:
OPENSSL_assert(b <= sizeof ctx->buf);
这里b
是大小当前密码的一个块。这个断言是有道理的,但我仍然无法弄清楚它是如何在我的代码中失败的。
我试图解决这个问题好几天了,我会很感激任何意见。
UPDATE:下面是evp_enc.c两行:
b=ctx->cipher->block_size;
OPENSSL_assert(b <= sizeof ctx->buf);
根据码,b是块大小为当前密码,用于aes_256_cbc它是16位长。
断言意味着'B'比'的sizeof(则将ctx-> BUF)'更大。 “b”代表什么? – 2013-03-12 01:32:09