Try using BIO_new_mem_buf() instead. https://www.openssl.org/docs/crypto/BIO_s_mem.html
-----Original Message----- From: owner-openssl-us...@openssl.org [mailto:owner-openssl-us...@openssl.org] On Behalf Of Ico Sent: Monday, July 07, 2014 2:17 PM To: openssl-users Subject: Decrypting from memory bio vs file bio Hi all, I've got a small snippet of code to decode some aes-128-cbc data. The encrypted data 16 bytes long, decoding to 7 bytes "\x02\x00hallo". Decoding using BIO's, works ok when the input BIO is a file BIO but fails when the input is a memory buffer BIO. In the latter case the BIO_read from the cipher bio returns -1. See the snippet below or at http://pastebin.com/raw.php?i=1fxLQkFa Change the 'if(1)' in 'if(0)' to switch between the two input bios. I noticed that the decrypting works ok if I write some additional data in the input memory buffer using BIO_write(), but I believe this should not be necessary. The data decodes properly using the openssl command line: openssl aes-128-cbc -d \ -K 2b7e151628aed2a6abf7158809cf4f3c \ -iv a76d933653cb191de0b5ef789727fc64 Any insight in my problem much appreciated. Ico #include <stdio.h> #include <assert.h> #include <openssl/evp.h> #include <openssl/bio.h> char data[] = { 0xd7, 0x40, 0x9c, 0xe9, 0x81, 0xff, 0x41, 0xf1, 0xf8, 0x61, 0xf5, 0xa9, 0x36, 0x99, 0x5b, 0x07 }; char key[] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c }; char iv[] = { 0xa7, 0x6d, 0x93, 0x36, 0x53, 0xcb, 0x19, 0x1d, 0xe0, 0xb5, 0xef, 0x78, 0x97, 0x27, 0xfc, 0x64 }; int main(int argc, char **argv) { int r; OpenSSL_add_all_digests(); OpenSSL_add_all_ciphers(); BIO *bio; if(1) { bio = BIO_new(BIO_s_mem()); r = BIO_write(bio, data, sizeof(data)); assert(r == sizeof(data)); } else { FILE *f = fopen("/tmp/flop", "w"); fwrite(data, 1, sizeof(data), f); fclose(f); bio = BIO_new_file("/tmp/flop", "r"); } BIO *bio_dec = BIO_new(BIO_f_cipher()); BIO_set_cipher(bio_dec, EVP_aes_128_cbc(), key, iv, 0); BIO_push(bio_dec, bio); char flop[2048]; r = BIO_read(bio_dec, flop, sizeof flop-1); assert(r != -1); flop[r] = '\0'; printf("r=%d '%s'\n", r, flop+2); return 0; } -- :wq ^X^Cy^K^X^C^C^C^C ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
