diff options
Diffstat (limited to 'libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c')
-rw-r--r-- | libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c b/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c new file mode 100644 index 0000000..3e68eb8 --- /dev/null +++ b/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c @@ -0,0 +1,55 @@ +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org + */ +#include "tomcrypt.h" + +/** + @file pkcs_1_i2osp.c + Integer to Octet I2OSP, Tom St Denis +*/ + +#ifdef PKCS_1 + +/* always stores the same # of bytes, pads with leading zero bytes + as required + */ + +/** + PKCS #1 Integer to binary + @param n The integer to store + @param modulus_len The length of the RSA modulus + @param out [out] The destination for the integer + @return CRYPT_OK if successful +*/ +int pkcs_1_i2osp(mp_int *n, unsigned long modulus_len, unsigned char *out) +{ + int err; + unsigned long size; + + size = mp_unsigned_bin_size(n); + + if (size > modulus_len) { + return CRYPT_BUFFER_OVERFLOW; + } + + /* store it */ + zeromem(out, modulus_len); + if ((err = mp_to_unsigned_bin(n, out+(modulus_len-size))) != MP_OKAY) { + return mpi_to_ltc_error(err); + } + return CRYPT_OK; +} + +#endif /* PKCS_1 */ + + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c,v $ */ +/* $Revision: 1.3 $ */ +/* $Date: 2005/05/05 14:35:59 $ */ |