diff options
Diffstat (limited to 'src/pk/rsa/rsa_decrypt_key.c')
| -rw-r--r-- | src/pk/rsa/rsa_decrypt_key.c | 64 |
1 files changed, 38 insertions, 26 deletions
diff --git a/src/pk/rsa/rsa_decrypt_key.c b/src/pk/rsa/rsa_decrypt_key.c index 7cea807..3dce20f 100644 --- a/src/pk/rsa/rsa_decrypt_key.c +++ b/src/pk/rsa/rsa_decrypt_key.c @@ -6,19 +6,19 @@ * The library is free for all purposes without any express * guarantee it works. * - * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org + * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com */ #include "tomcrypt.h" /** @file rsa_decrypt_key.c - RSA PKCS #1 OAEP Decryption, Tom St Denis -*/ + RSA PKCS #1 Decryption, Tom St Denis and Andreas Lange +*/ #ifdef MRSA /** - (PKCS #1 v2.0) decrypt then OAEP depad + PKCS #1 decrypt then v1.5 or OAEP depad @param in The ciphertext @param inlen The length of the ciphertext (octets) @param out [out] The plaintext @@ -26,20 +26,21 @@ @param lparam The system "lparam" value @param lparamlen The length of the lparam value (octets) @param hash_idx The index of the hash desired + @param padding Type of padding (LTC_PKCS_1_OAEP or LTC_PKCS_1_V1_5) @param stat [out] Result of the decryption, 1==valid, 0==invalid @param key The corresponding private RSA key @return CRYPT_OK if succcessul (even if invalid) */ -int rsa_decrypt_key(const unsigned char *in, unsigned long inlen, - unsigned char *out, unsigned long *outlen, - const unsigned char *lparam, unsigned long lparamlen, - int hash_idx, int *stat, - rsa_key *key) +int rsa_decrypt_key_ex(const unsigned char *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen, + const unsigned char *lparam, unsigned long lparamlen, + int hash_idx, int padding, + int *stat, rsa_key *key) { unsigned long modulus_bitlen, modulus_bytelen, x; int err; unsigned char *tmp; - + LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); LTC_ARGCHK(key != NULL); @@ -48,16 +49,25 @@ int rsa_decrypt_key(const unsigned char *in, unsigned long inlen, /* default to invalid */ *stat = 0; - /* valid hash ? */ - if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { - return err; + /* valid padding? */ + + if ((padding != LTC_PKCS_1_V1_5) && + (padding != LTC_PKCS_1_OAEP)) { + return CRYPT_PK_INVALID_PADDING; } - + + if (padding == LTC_PKCS_1_OAEP) { + /* valid hash ? */ + if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { + return err; + } + } + /* get modulus len in bits */ - modulus_bitlen = mp_count_bits(&(key->N)); + modulus_bitlen = mp_count_bits( (key->N)); /* outlen must be at least the size of the modulus */ - modulus_bytelen = mp_unsigned_bin_size(&(key->N)); + modulus_bytelen = mp_unsigned_bin_size( (key->N)); if (modulus_bytelen != inlen) { return CRYPT_INVALID_PACKET; } @@ -70,24 +80,26 @@ int rsa_decrypt_key(const unsigned char *in, unsigned long inlen, /* rsa decode the packet */ x = inlen; - if ((err = rsa_exptmod(in, inlen, tmp, &x, PK_PRIVATE, key)) != CRYPT_OK) { + if ((err = ltc_mp.rsa_me(in, inlen, tmp, &x, PK_PRIVATE, key)) != CRYPT_OK) { XFREE(tmp); return err; } - /* now OAEP decode the packet */ - err = pkcs_1_oaep_decode(tmp, x, lparam, lparamlen, modulus_bitlen, hash_idx, - out, outlen, stat); + if (padding == LTC_PKCS_1_OAEP) { + /* now OAEP decode the packet */ + err = pkcs_1_oaep_decode(tmp, x, lparam, lparamlen, modulus_bitlen, hash_idx, + out, outlen, stat); + } else { + /* now PKCS #1 v1.5 depad the packet */ + err = pkcs_1_v1_5_decode(tmp, x, LTC_PKCS_1_EME, modulus_bitlen, out, outlen, stat); + } + XFREE(tmp); return err; } #endif /* MRSA */ - - - - /* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_decrypt_key.c,v $ */ -/* $Revision: 1.3 $ */ -/* $Date: 2005/05/05 14:35:59 $ */ +/* $Revision: 1.8 $ */ +/* $Date: 2006/11/01 09:18:22 $ */ |