diff --git a/src/lib/crypto/crypto_tests/t_cksum.c b/src/lib/crypto/crypto_tests/t_cksum.c index a544d9e..50e8e7c 100644 --- a/src/lib/crypto/crypto_tests/t_cksum.c +++ b/src/lib/crypto/crypto_tests/t_cksum.c @@ -37,11 +37,21 @@ #if MD == 4 extern struct krb5_keyhash_provider krb5int_keyhash_md4des; #define khp krb5int_keyhash_md4des +static unsigned char knowncksum[] = { + 0xe3, 0xf7, 0x6a, 0x07, 0xf3, 0x40, 0x1e, 0x35, + 0x36, 0xb4, 0x3a, 0x3f, 0x54, 0x22, 0x6c, 0x39, + 0x42, 0x2c, 0x35, 0x68, 0x2c, 0x35, 0x48, 0x35 +}; #endif #if MD == 5 extern struct krb5_keyhash_provider krb5int_keyhash_md5des; #define khp krb5int_keyhash_md5des +static unsigned char knowncksum[] = { + 0xe3, 0xf7, 0x6a, 0x07, 0xf3, 0x40, 0x1e, 0x35, + 0x11, 0x43, 0xee, 0x6f, 0x4c, 0x09, 0xbe, 0x1e, + 0xdb, 0x42, 0x64, 0xd5, 0x50, 0x15, 0xdb, 0x53 +}; #endif static void @@ -77,7 +87,11 @@ main(argc, argv) krb5_keyblock keyblock; krb5_key key; krb5_error_code kret=0; - krb5_data plaintext, newstyle_checksum; + krb5_data plaintext, newstyle_checksum, knowncksum_dat; + char *known_plaintext = "this is a test"; + + knowncksum_dat.data = (char *)knowncksum; + knowncksum_dat.length = sizeof(knowncksum); /* this is a terrible seed, but that's ok for the test. */ @@ -118,6 +132,7 @@ main(argc, argv) } if (!valid) { printf("verify on new checksum failed\n"); + kret = 1; break; } printf("Verify succeeded for \"%s\"\n", argv[msgindex]); @@ -130,9 +145,26 @@ main(argc, argv) } if (valid) { printf("verify on new checksum succeeded, but shouldn't have\n"); + kret = 1; break; } printf("Verify of bad checksum OK for \"%s\"\n", argv[msgindex]); + if (strcmp(argv[msgindex], known_plaintext) == 0) { + if ((kret = (*(khp.verify))(key, 0, 0, &plaintext, &knowncksum_dat, + &valid))) { + printf("verify on known checksum choked with %d\n", kret); + break; + } + if (!valid) { + printf("verify on known checksum failed\n"); + kret = 1; + break; + } + } else { + printf("WARNING: input plaintext doesn't match plaintext " + "of known hash.\n" + "NOT verifying known checksum.\n"); + } kret = 0; } free(newstyle_checksum.data); diff --git a/src/lib/crypto/krb/keyhash_provider/k5_md4des.c b/src/lib/crypto/krb/keyhash_provider/k5_md4des.c index ef10a68..89d97f7 100644 --- a/src/lib/crypto/krb/keyhash_provider/k5_md4des.c +++ b/src/lib/crypto/krb/keyhash_provider/k5_md4des.c @@ -38,6 +38,30 @@ extern struct krb5_enc_provider krb5int_enc_des; +/* Derive a key by XOR with 0xF0 bytes. */ +static krb5_error_code +mk_xorkey(krb5_key origkey, krb5_key *xorkey) +{ + krb5_error_code retval = 0; + unsigned char xorbytes[8]; + krb5_keyblock xorkeyblock; + size_t i = 0; + + if (origkey->keyblock.length != sizeof(xorbytes)) + return KRB5_CRYPTO_INTERNAL; + memcpy(xorbytes, origkey->keyblock.contents, sizeof(xorbytes)); + for (i = 0; i < sizeof(xorbytes); i++) + xorbytes[i] ^= 0xf0; + + /* Do a shallow copy here. */ + xorkeyblock = origkey->keyblock; + xorkeyblock.contents = xorbytes; + + retval = krb5_k_create_key(0, &xorkeyblock, xorkey); + zap(xorbytes, sizeof(xorbytes)); + return retval; +} + static krb5_error_code k5_md4des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, const krb5_data *input, krb5_data *output) @@ -46,6 +70,7 @@ k5_md4des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, krb5_data data; krb5_MD4_CTX ctx; unsigned char conf[CONFLENGTH]; + krb5_key xorkey = NULL; struct krb5_enc_provider *enc = &krb5int_enc_des; if (output->length != (CONFLENGTH+RSA_MD4_CKSUM_LENGTH)) @@ -58,6 +83,10 @@ k5_md4des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, if ((ret = krb5_c_random_make_octets(/* XXX */ 0, &data))) return(ret); + ret = mk_xorkey(key, &xorkey); + if (ret) + return ret; + /* hash the confounder, then the input data */ krb5int_MD4Init(&ctx); @@ -71,7 +100,9 @@ k5_md4des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, memcpy(output->data, conf, CONFLENGTH); memcpy(output->data+CONFLENGTH, ctx.digest, RSA_MD4_CKSUM_LENGTH); - ret = enc->encrypt(key, NULL, output, output); + ret = enc->encrypt(xorkey, NULL, output, output); + + krb5_k_free_key(NULL, xorkey); return (ret); } @@ -85,10 +116,14 @@ k5_md4des_verify(krb5_key key, krb5_keyusage usage, krb5_error_code ret; krb5_MD4_CTX ctx; unsigned char plaintext[CONFLENGTH+RSA_MD4_CKSUM_LENGTH]; + krb5_key xorkey = NULL; int compathash = 0; struct krb5_enc_provider *enc = &krb5int_enc_des; krb5_data output, iv; + iv.data = NULL; + iv.length = 0; + if (key->keyblock.length != 8) return(KRB5_BAD_KEYSIZE); if (hash->length != (CONFLENGTH+RSA_MD4_CKSUM_LENGTH)) { @@ -109,20 +144,23 @@ k5_md4des_verify(krb5_key key, krb5_keyusage usage, iv.length = key->keyblock.length; if (key->keyblock.contents) memcpy(iv.data, key->keyblock.contents, key->keyblock.length); + } else { + ret = mk_xorkey(key, &xorkey); + if (ret) + return ret; } /* decrypt it */ - output.data = plaintext; + output.data = (char *)plaintext; output.length = hash->length; if (!compathash) { - ret = enc->decrypt(key, NULL, hash, &output); + ret = enc->decrypt(xorkey, NULL, hash, &output); + krb5_k_free_key(NULL, xorkey); } else { ret = enc->decrypt(key, &iv, hash, &output); - } - - if (compathash && iv.data) { - free (iv.data); + zap(iv.data, iv.length); + free(iv.data); } if (ret) return(ret); diff --git a/src/lib/crypto/krb/keyhash_provider/k5_md5des.c b/src/lib/crypto/krb/keyhash_provider/k5_md5des.c index eb189c2..4a3d623 100644 --- a/src/lib/crypto/krb/keyhash_provider/k5_md5des.c +++ b/src/lib/crypto/krb/keyhash_provider/k5_md5des.c @@ -38,6 +38,30 @@ extern struct krb5_enc_provider krb5int_enc_des; +/* Derive a key by XOR with 0xF0 bytes. */ +static krb5_error_code +mk_xorkey(krb5_key origkey, krb5_key *xorkey) +{ + krb5_error_code retval = 0; + unsigned char xorbytes[8]; + krb5_keyblock xorkeyblock; + size_t i = 0; + + if (origkey->keyblock.length != sizeof(xorbytes)) + return KRB5_CRYPTO_INTERNAL; + memcpy(xorbytes, origkey->keyblock.contents, sizeof(xorbytes)); + for (i = 0; i < sizeof(xorbytes); i++) + xorbytes[i] ^= 0xf0; + + /* Do a shallow copy here. */ + xorkeyblock = origkey->keyblock; + xorkeyblock.contents = xorbytes; + + retval = krb5_k_create_key(0, &xorkeyblock, xorkey); + zap(xorbytes, sizeof(xorbytes)); + return retval; +} + static krb5_error_code k5_md5des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, const krb5_data *input, krb5_data *output) @@ -46,6 +70,7 @@ k5_md5des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, krb5_data data; krb5_MD5_CTX ctx; unsigned char conf[CONFLENGTH]; + krb5_key xorkey = NULL; struct krb5_enc_provider *enc = &krb5int_enc_des; if (output->length != (CONFLENGTH+RSA_MD5_CKSUM_LENGTH)) @@ -58,6 +83,10 @@ k5_md5des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, if ((ret = krb5_c_random_make_octets(/* XXX */ 0, &data))) return(ret); + ret = mk_xorkey(key, &xorkey); + if (ret) + return ret; + /* hash the confounder, then the input data */ krb5int_MD5Init(&ctx); @@ -71,7 +100,9 @@ k5_md5des_hash(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, memcpy(output->data, conf, CONFLENGTH); memcpy(output->data+CONFLENGTH, ctx.digest, RSA_MD5_CKSUM_LENGTH); - ret = enc->encrypt(key, NULL, output, output); + ret = enc->encrypt(xorkey, NULL, output, output); + + krb5_k_free_key(NULL, xorkey); return ret; @@ -85,10 +116,14 @@ k5_md5des_verify(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, krb5_error_code ret; krb5_MD5_CTX ctx; unsigned char plaintext[CONFLENGTH+RSA_MD5_CKSUM_LENGTH]; + krb5_key xorkey = NULL; int compathash = 0; struct krb5_enc_provider *enc = &krb5int_enc_des; krb5_data output, iv; + iv.data = NULL; + iv.length = 0; + if (key->keyblock.length != 8) return(KRB5_BAD_KEYSIZE); @@ -109,20 +144,23 @@ k5_md5des_verify(krb5_key key, krb5_keyusage usage, const krb5_data *ivec, iv.length = key->keyblock.length; if (key->keyblock.contents) memcpy(iv.data, key->keyblock.contents, key->keyblock.length); + } else { + ret = mk_xorkey(key, &xorkey); + if (ret) + return ret; } /* decrypt it */ - output.data = plaintext; + output.data = (char *)plaintext; output.length = hash->length; if (!compathash) { - ret = enc->decrypt(key, NULL, hash, &output); + ret = enc->decrypt(xorkey, NULL, hash, &output); + krb5_k_free_key(NULL, xorkey); } else { ret = enc->decrypt(key, &iv, hash, &output); - } - - if (compathash && iv.data) { - free (iv.data); + zap(iv.data, iv.length); + free(iv.data); } if (ret) return(ret);