X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fmisc%2Fpkcs5%2Fpkcs_5_1.c;fp=libtomcrypt%2Fsrc%2Fmisc%2Fpkcs5%2Fpkcs_5_1.c;h=10325de221d82998e5d2159b734c624f77aea01b;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage diff --git a/libtomcrypt/src/misc/pkcs5/pkcs_5_1.c b/libtomcrypt/src/misc/pkcs5/pkcs_5_1.c new file mode 100644 index 0000000..10325de --- /dev/null +++ b/libtomcrypt/src/misc/pkcs5/pkcs_5_1.c @@ -0,0 +1,187 @@ +/* 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. + */ +#include "tomcrypt.h" + +/** + @file pkcs_5_1.c + PKCS #5, Algorithm #1, Tom St Denis +*/ +#ifdef LTC_PKCS_5 +/** + Execute PKCS #5 v1 in strict or OpenSSL EVP_BytesToKey()-compat mode. + + PKCS#5 v1 specifies that the output key length can be no larger than + the hash output length. OpenSSL unilaterally extended that by repeating + the hash process on a block-by-block basis for as long as needed to make + bigger keys. If you want to be compatible with KDF for e.g. "openssl enc", + you'll want that. + + If you want strict PKCS behavior, turn openssl_compat off. Or (more + likely), use one of the convenience functions below. + + @param password The password (or key) + @param password_len The length of the password (octet) + @param salt The salt (or nonce) which is 8 octets long + @param iteration_count The PKCS #5 v1 iteration count + @param hash_idx The index of the hash desired + @param out [out] The destination for this algorithm + @param outlen [in/out] The max size and resulting size of the algorithm output + @param openssl_compat [in] Whether or not to grow the key to the buffer size ala OpenSSL + @return CRYPT_OK if successful +*/ +static int _pkcs_5_alg1_common(const unsigned char *password, + unsigned long password_len, + const unsigned char *salt, + int iteration_count, int hash_idx, + unsigned char *out, unsigned long *outlen, + int openssl_compat) +{ + int err; + unsigned long x; + hash_state *md; + unsigned char *buf; + /* Storage vars in case we need to support > hashsize (OpenSSL compat) */ + unsigned long block = 0, iter; + /* How many bytes to put in the outbut buffer (convenience calc) */ + unsigned long outidx = 0, nb = 0; + + LTC_ARGCHK(password != NULL); + LTC_ARGCHK(salt != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + + /* test hash IDX */ + if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { + return err; + } + + /* allocate memory */ + md = XMALLOC(sizeof(hash_state)); + buf = XMALLOC(MAXBLOCKSIZE); + if (md == NULL || buf == NULL) { + if (md != NULL) { + XFREE(md); + } + if (buf != NULL) { + XFREE(buf); + } + return CRYPT_MEM; + } + + while(block * hash_descriptor[hash_idx].hashsize < *outlen) { + + /* hash initial (maybe previous hash) + password + salt */ + if ((err = hash_descriptor[hash_idx].init(md)) != CRYPT_OK) { + goto LBL_ERR; + } + /* in OpenSSL mode, we first hash the previous result for blocks 2-n */ + if (openssl_compat && block) { + if ((err = hash_descriptor[hash_idx].process(md, buf, hash_descriptor[hash_idx].hashsize)) != CRYPT_OK) { + goto LBL_ERR; + } + } + if ((err = hash_descriptor[hash_idx].process(md, password, password_len)) != CRYPT_OK) { + goto LBL_ERR; + } + if ((err = hash_descriptor[hash_idx].process(md, salt, 8)) != CRYPT_OK) { + goto LBL_ERR; + } + if ((err = hash_descriptor[hash_idx].done(md, buf)) != CRYPT_OK) { + goto LBL_ERR; + } + + iter = iteration_count; + while (--iter) { + /* code goes here. */ + x = MAXBLOCKSIZE; + if ((err = hash_memory(hash_idx, buf, hash_descriptor[hash_idx].hashsize, buf, &x)) != CRYPT_OK) { + goto LBL_ERR; + } + } + + /* limit the size of the copy to however many bytes we have left in + the output buffer (and how many bytes we have to copy) */ + outidx = block*hash_descriptor[hash_idx].hashsize; + nb = hash_descriptor[hash_idx].hashsize; + if(outidx+nb > *outlen) + nb = *outlen - outidx; + if(nb > 0) + XMEMCPY(out+outidx, buf, nb); + + block++; + if (!openssl_compat) + break; + } + /* In strict mode, we always return the hashsize, in compat we filled it + as much as was requested, so we leave it alone. */ + if(!openssl_compat) + *outlen = hash_descriptor[hash_idx].hashsize; + + err = CRYPT_OK; +LBL_ERR: +#ifdef LTC_CLEAN_STACK + zeromem(buf, MAXBLOCKSIZE); + zeromem(md, sizeof(hash_state)); +#endif + + XFREE(buf); + XFREE(md); + + return err; +} + +/** + Execute PKCS #5 v1 - Strict mode (no OpenSSL-compatible extension) + @param password The password (or key) + @param password_len The length of the password (octet) + @param salt The salt (or nonce) which is 8 octets long + @param iteration_count The PKCS #5 v1 iteration count + @param hash_idx The index of the hash desired + @param out [out] The destination for this algorithm + @param outlen [in/out] The max size and resulting size of the algorithm output + @return CRYPT_OK if successful +*/ +int pkcs_5_alg1(const unsigned char *password, unsigned long password_len, + const unsigned char *salt, + int iteration_count, int hash_idx, + unsigned char *out, unsigned long *outlen) +{ + return _pkcs_5_alg1_common(password, password_len, salt, iteration_count, + hash_idx, out, outlen, 0); +} + +/** + Execute PKCS #5 v1 - OpenSSL-extension-compatible mode + + Use this one if you need to derive keys as "openssl enc" does by default. + OpenSSL (for better or worse), uses MD5 as the hash and iteration_count=1. + @param password The password (or key) + @param password_len The length of the password (octet) + @param salt The salt (or nonce) which is 8 octets long + @param iteration_count The PKCS #5 v1 iteration count + @param hash_idx The index of the hash desired + @param out [out] The destination for this algorithm + @param outlen [in/out] The max size and resulting size of the algorithm output + @return CRYPT_OK if successful +*/ +int pkcs_5_alg1_openssl(const unsigned char *password, + unsigned long password_len, + const unsigned char *salt, + int iteration_count, int hash_idx, + unsigned char *out, unsigned long *outlen) +{ + return _pkcs_5_alg1_common(password, password_len, salt, iteration_count, + hash_idx, out, outlen, 1); +} + +#endif + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */