2 * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include <openssl/evp.h>
11 #include <openssl/core_numbers.h>
12 #include "internal/refcount.h"
15 * Don't free up md_ctx->pctx in EVP_MD_CTX_reset, use the reserved flag
18 #define EVP_MD_CTX_FLAG_KEEP_PKEY_CTX 0x0400
20 struct evp_pkey_ctx_st {
21 /* Method associated with this operation */
22 const EVP_PKEY_METHOD *pmeth;
23 /* Engine that implements this method or NULL if builtin */
25 /* Key: may be NULL */
27 /* Peer key for key agreement, may be NULL */
29 /* Actual operation */
31 /* Algorithm specific data */
33 /* Application specific data */
36 EVP_PKEY_gen_cb *pkey_gencb;
37 /* implementation specific keygen data */
39 int keygen_info_count;
40 } /* EVP_PKEY_CTX */ ;
42 #define EVP_PKEY_FLAG_DYNAMIC 1
44 struct evp_pkey_method_st {
47 int (*init) (EVP_PKEY_CTX *ctx);
48 int (*copy) (EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src);
49 void (*cleanup) (EVP_PKEY_CTX *ctx);
50 int (*paramgen_init) (EVP_PKEY_CTX *ctx);
51 int (*paramgen) (EVP_PKEY_CTX *ctx, EVP_PKEY *pkey);
52 int (*keygen_init) (EVP_PKEY_CTX *ctx);
53 int (*keygen) (EVP_PKEY_CTX *ctx, EVP_PKEY *pkey);
54 int (*sign_init) (EVP_PKEY_CTX *ctx);
55 int (*sign) (EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
56 const unsigned char *tbs, size_t tbslen);
57 int (*verify_init) (EVP_PKEY_CTX *ctx);
58 int (*verify) (EVP_PKEY_CTX *ctx,
59 const unsigned char *sig, size_t siglen,
60 const unsigned char *tbs, size_t tbslen);
61 int (*verify_recover_init) (EVP_PKEY_CTX *ctx);
62 int (*verify_recover) (EVP_PKEY_CTX *ctx,
63 unsigned char *rout, size_t *routlen,
64 const unsigned char *sig, size_t siglen);
65 int (*signctx_init) (EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx);
66 int (*signctx) (EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
68 int (*verifyctx_init) (EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx);
69 int (*verifyctx) (EVP_PKEY_CTX *ctx, const unsigned char *sig, int siglen,
71 int (*encrypt_init) (EVP_PKEY_CTX *ctx);
72 int (*encrypt) (EVP_PKEY_CTX *ctx, unsigned char *out, size_t *outlen,
73 const unsigned char *in, size_t inlen);
74 int (*decrypt_init) (EVP_PKEY_CTX *ctx);
75 int (*decrypt) (EVP_PKEY_CTX *ctx, unsigned char *out, size_t *outlen,
76 const unsigned char *in, size_t inlen);
77 int (*derive_init) (EVP_PKEY_CTX *ctx);
78 int (*derive) (EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen);
79 int (*ctrl) (EVP_PKEY_CTX *ctx, int type, int p1, void *p2);
80 int (*ctrl_str) (EVP_PKEY_CTX *ctx, const char *type, const char *value);
81 int (*digestsign) (EVP_MD_CTX *ctx, unsigned char *sig, size_t *siglen,
82 const unsigned char *tbs, size_t tbslen);
83 int (*digestverify) (EVP_MD_CTX *ctx, const unsigned char *sig,
84 size_t siglen, const unsigned char *tbs,
86 int (*check) (EVP_PKEY *pkey);
87 int (*public_check) (EVP_PKEY *pkey);
88 int (*param_check) (EVP_PKEY *pkey);
90 int (*digest_custom) (EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx);
91 } /* EVP_PKEY_METHOD */ ;
93 DEFINE_STACK_OF_CONST(EVP_PKEY_METHOD)
95 void evp_pkey_set_cb_translate(BN_GENCB *cb, EVP_PKEY_CTX *ctx);
97 extern const EVP_PKEY_METHOD cmac_pkey_meth;
98 extern const EVP_PKEY_METHOD dh_pkey_meth;
99 extern const EVP_PKEY_METHOD dhx_pkey_meth;
100 extern const EVP_PKEY_METHOD dsa_pkey_meth;
101 extern const EVP_PKEY_METHOD ec_pkey_meth;
102 extern const EVP_PKEY_METHOD sm2_pkey_meth;
103 extern const EVP_PKEY_METHOD ecx25519_pkey_meth;
104 extern const EVP_PKEY_METHOD ecx448_pkey_meth;
105 extern const EVP_PKEY_METHOD ed25519_pkey_meth;
106 extern const EVP_PKEY_METHOD ed448_pkey_meth;
107 extern const EVP_PKEY_METHOD hmac_pkey_meth;
108 extern const EVP_PKEY_METHOD rsa_pkey_meth;
109 extern const EVP_PKEY_METHOD rsa_pss_pkey_meth;
110 extern const EVP_PKEY_METHOD scrypt_pkey_meth;
111 extern const EVP_PKEY_METHOD tls1_prf_pkey_meth;
112 extern const EVP_PKEY_METHOD hkdf_pkey_meth;
113 extern const EVP_PKEY_METHOD poly1305_pkey_meth;
114 extern const EVP_PKEY_METHOD siphash_pkey_meth;
116 /* struct evp_mac_impl_st is defined by the implementation */
117 typedef struct evp_mac_impl_st EVP_MAC_IMPL;
120 EVP_MAC_IMPL *(*new) (void);
121 int (*copy) (EVP_MAC_IMPL *macdst, EVP_MAC_IMPL *macsrc);
122 void (*free) (EVP_MAC_IMPL *macctx);
123 size_t (*size) (EVP_MAC_IMPL *macctx);
124 int (*init) (EVP_MAC_IMPL *macctx);
125 int (*update) (EVP_MAC_IMPL *macctx, const unsigned char *data,
127 int (*final) (EVP_MAC_IMPL *macctx, unsigned char *out);
128 int (*ctrl) (EVP_MAC_IMPL *macctx, int cmd, va_list args);
129 int (*ctrl_str) (EVP_MAC_IMPL *macctx, const char *type, const char *value);
132 extern const EVP_MAC blake2b_mac_meth;
133 extern const EVP_MAC blake2s_mac_meth;
134 extern const EVP_MAC cmac_meth;
135 extern const EVP_MAC gmac_meth;
136 extern const EVP_MAC hmac_meth;
137 extern const EVP_MAC kmac128_meth;
138 extern const EVP_MAC kmac256_meth;
139 extern const EVP_MAC siphash_meth;
140 extern const EVP_MAC poly1305_meth;
142 /* Internal keccak algorithms used for KMAC */
143 const EVP_MD *evp_keccak_kmac128(void);
144 const EVP_MD *evp_keccak_kmac256(void);
147 * This function is internal for now, but can be made external when needed.
148 * The documentation would read:
150 * EVP_add_mac() adds the MAC implementation C<mac> to the internal
153 int EVP_add_mac(const EVP_MAC *mac);
155 /* struct evp_kdf_impl_st is defined by the implementation */
156 typedef struct evp_kdf_impl_st EVP_KDF_IMPL;
159 EVP_KDF_IMPL *(*new) (void);
160 void (*free) (EVP_KDF_IMPL *impl);
161 void (*reset) (EVP_KDF_IMPL *impl);
162 int (*ctrl) (EVP_KDF_IMPL *impl, int cmd, va_list args);
163 int (*ctrl_str) (EVP_KDF_IMPL *impl, const char *type, const char *value);
164 size_t (*size) (EVP_KDF_IMPL *impl);
165 int (*derive) (EVP_KDF_IMPL *impl, unsigned char *key, size_t keylen);
168 extern const EVP_KDF_METHOD pbkdf2_kdf_meth;
169 extern const EVP_KDF_METHOD scrypt_kdf_meth;
170 extern const EVP_KDF_METHOD tls1_prf_kdf_meth;
171 extern const EVP_KDF_METHOD hkdf_kdf_meth;
172 extern const EVP_KDF_METHOD sshkdf_kdf_meth;
173 extern const EVP_KDF_METHOD ss_kdf_meth;
179 /* Legacy structure members */
180 /* TODO(3.0): Remove these */
184 int (*init) (EVP_MD_CTX *ctx);
185 int (*update) (EVP_MD_CTX *ctx, const void *data, size_t count);
186 int (*final) (EVP_MD_CTX *ctx, unsigned char *md);
187 int (*copy) (EVP_MD_CTX *to, const EVP_MD_CTX *from);
188 int (*cleanup) (EVP_MD_CTX *ctx);
190 int ctx_size; /* how big does the ctx->md_data need to be */
191 /* control function */
192 int (*md_ctrl) (EVP_MD_CTX *ctx, int cmd, int p1, void *p2);
194 /* New structure members */
195 /* TODO(3.0): Remove above comment when legacy has gone */
197 CRYPTO_REF_COUNT refcnt;
199 OSSL_OP_digest_newctx_fn *newctx;
200 OSSL_OP_digest_init_fn *dinit;
201 OSSL_OP_digest_update_fn *dupdate;
202 OSSL_OP_digest_final_fn *dfinal;
203 OSSL_OP_digest_digest_fn *digest;
204 OSSL_OP_digest_freectx_fn *freectx;
205 OSSL_OP_digest_dupctx_fn *dupctx;
206 OSSL_OP_digest_size_fn *size;
207 OSSL_OP_digest_block_size_fn *dblock_size;
211 struct evp_cipher_st {
215 /* Default value for variable length ciphers */
219 /* Legacy structure members */
220 /* TODO(3.0): Remove these */
224 int (*init) (EVP_CIPHER_CTX *ctx, const unsigned char *key,
225 const unsigned char *iv, int enc);
226 /* encrypt/decrypt data */
227 int (*do_cipher) (EVP_CIPHER_CTX *ctx, unsigned char *out,
228 const unsigned char *in, size_t inl);
230 int (*cleanup) (EVP_CIPHER_CTX *);
231 /* how big ctx->cipher_data needs to be */
233 /* Populate a ASN1_TYPE with parameters */
234 int (*set_asn1_parameters) (EVP_CIPHER_CTX *, ASN1_TYPE *);
235 /* Get parameters from a ASN1_TYPE */
236 int (*get_asn1_parameters) (EVP_CIPHER_CTX *, ASN1_TYPE *);
237 /* Miscellaneous operations */
238 int (*ctrl) (EVP_CIPHER_CTX *, int type, int arg, void *ptr);
239 /* Application data */
242 /* New structure members */
243 /* TODO(3.0): Remove above comment when legacy has gone */
245 CRYPTO_REF_COUNT refcnt;
247 OSSL_OP_cipher_newctx_fn *newctx;
248 OSSL_OP_cipher_encrypt_init_fn *einit;
249 OSSL_OP_cipher_decrypt_init_fn *dinit;
250 OSSL_OP_cipher_update_fn *cupdate;
251 OSSL_OP_cipher_final_fn *cfinal;
252 OSSL_OP_cipher_freectx_fn *freectx;
253 OSSL_OP_cipher_dupctx_fn *dupctx;
254 OSSL_OP_cipher_key_length_fn *key_length;
255 OSSL_OP_cipher_get_params_fn *get_params;
256 OSSL_OP_cipher_get_params_fn *set_params;
259 /* Macros to code block cipher wrappers */
261 /* Wrapper functions for each cipher mode */
263 #define EVP_C_DATA(kstruct, ctx) \
264 ((kstruct *)EVP_CIPHER_CTX_get_cipher_data(ctx))
266 #define BLOCK_CIPHER_ecb_loop() \
268 bl = EVP_CIPHER_CTX_cipher(ctx)->block_size; \
269 if (inl < bl) return 1;\
271 for (i=0; i <= inl; i+=bl)
273 #define BLOCK_CIPHER_func_ecb(cname, cprefix, kstruct, ksched) \
274 static int cname##_ecb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl) \
276 BLOCK_CIPHER_ecb_loop() \
277 cprefix##_ecb_encrypt(in + i, out + i, &EVP_C_DATA(kstruct,ctx)->ksched, EVP_CIPHER_CTX_encrypting(ctx)); \
281 #define EVP_MAXCHUNK ((size_t)1<<(sizeof(long)*8-2))
283 #define BLOCK_CIPHER_func_ofb(cname, cprefix, cbits, kstruct, ksched) \
284 static int cname##_ofb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl) \
286 while(inl>=EVP_MAXCHUNK) {\
287 int num = EVP_CIPHER_CTX_num(ctx);\
288 cprefix##_ofb##cbits##_encrypt(in, out, (long)EVP_MAXCHUNK, &EVP_C_DATA(kstruct,ctx)->ksched, EVP_CIPHER_CTX_iv_noconst(ctx), &num); \
289 EVP_CIPHER_CTX_set_num(ctx, num);\
295 int num = EVP_CIPHER_CTX_num(ctx);\
296 cprefix##_ofb##cbits##_encrypt(in, out, (long)inl, &EVP_C_DATA(kstruct,ctx)->ksched, EVP_CIPHER_CTX_iv_noconst(ctx), &num); \
297 EVP_CIPHER_CTX_set_num(ctx, num);\
302 #define BLOCK_CIPHER_func_cbc(cname, cprefix, kstruct, ksched) \
303 static int cname##_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl) \
305 while(inl>=EVP_MAXCHUNK) \
307 cprefix##_cbc_encrypt(in, out, (long)EVP_MAXCHUNK, &EVP_C_DATA(kstruct,ctx)->ksched, EVP_CIPHER_CTX_iv_noconst(ctx), EVP_CIPHER_CTX_encrypting(ctx));\
313 cprefix##_cbc_encrypt(in, out, (long)inl, &EVP_C_DATA(kstruct,ctx)->ksched, EVP_CIPHER_CTX_iv_noconst(ctx), EVP_CIPHER_CTX_encrypting(ctx));\
317 #define BLOCK_CIPHER_func_cfb(cname, cprefix, cbits, kstruct, ksched) \
318 static int cname##_cfb##cbits##_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl) \
320 size_t chunk = EVP_MAXCHUNK;\
321 if (cbits == 1) chunk >>= 3;\
322 if (inl < chunk) chunk = inl;\
323 while (inl && inl >= chunk)\
325 int num = EVP_CIPHER_CTX_num(ctx);\
326 cprefix##_cfb##cbits##_encrypt(in, out, (long) \
328 && !EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS) \
329 ? chunk*8 : chunk), \
330 &EVP_C_DATA(kstruct, ctx)->ksched, EVP_CIPHER_CTX_iv_noconst(ctx),\
331 &num, EVP_CIPHER_CTX_encrypting(ctx));\
332 EVP_CIPHER_CTX_set_num(ctx, num);\
336 if (inl < chunk) chunk = inl;\
341 #define BLOCK_CIPHER_all_funcs(cname, cprefix, cbits, kstruct, ksched) \
342 BLOCK_CIPHER_func_cbc(cname, cprefix, kstruct, ksched) \
343 BLOCK_CIPHER_func_cfb(cname, cprefix, cbits, kstruct, ksched) \
344 BLOCK_CIPHER_func_ecb(cname, cprefix, kstruct, ksched) \
345 BLOCK_CIPHER_func_ofb(cname, cprefix, cbits, kstruct, ksched)
347 #define BLOCK_CIPHER_def1(cname, nmode, mode, MODE, kstruct, nid, block_size, \
348 key_len, iv_len, flags, init_key, cleanup, \
349 set_asn1, get_asn1, ctrl) \
350 static const EVP_CIPHER cname##_##mode = { \
351 nid##_##nmode, block_size, key_len, iv_len, \
352 flags | EVP_CIPH_##MODE##_MODE, \
354 cname##_##mode##_cipher, \
361 const EVP_CIPHER *EVP_##cname##_##mode(void) { return &cname##_##mode; }
363 #define BLOCK_CIPHER_def_cbc(cname, kstruct, nid, block_size, key_len, \
364 iv_len, flags, init_key, cleanup, set_asn1, \
366 BLOCK_CIPHER_def1(cname, cbc, cbc, CBC, kstruct, nid, block_size, key_len, \
367 iv_len, flags, init_key, cleanup, set_asn1, get_asn1, ctrl)
369 #define BLOCK_CIPHER_def_cfb(cname, kstruct, nid, key_len, \
370 iv_len, cbits, flags, init_key, cleanup, \
371 set_asn1, get_asn1, ctrl) \
372 BLOCK_CIPHER_def1(cname, cfb##cbits, cfb##cbits, CFB, kstruct, nid, 1, \
373 key_len, iv_len, flags, init_key, cleanup, set_asn1, \
376 #define BLOCK_CIPHER_def_ofb(cname, kstruct, nid, key_len, \
377 iv_len, cbits, flags, init_key, cleanup, \
378 set_asn1, get_asn1, ctrl) \
379 BLOCK_CIPHER_def1(cname, ofb##cbits, ofb, OFB, kstruct, nid, 1, \
380 key_len, iv_len, flags, init_key, cleanup, set_asn1, \
383 #define BLOCK_CIPHER_def_ecb(cname, kstruct, nid, block_size, key_len, \
384 flags, init_key, cleanup, set_asn1, \
386 BLOCK_CIPHER_def1(cname, ecb, ecb, ECB, kstruct, nid, block_size, key_len, \
387 0, flags, init_key, cleanup, set_asn1, get_asn1, ctrl)
389 #define BLOCK_CIPHER_defs(cname, kstruct, \
390 nid, block_size, key_len, iv_len, cbits, flags, \
391 init_key, cleanup, set_asn1, get_asn1, ctrl) \
392 BLOCK_CIPHER_def_cbc(cname, kstruct, nid, block_size, key_len, iv_len, flags, \
393 init_key, cleanup, set_asn1, get_asn1, ctrl) \
394 BLOCK_CIPHER_def_cfb(cname, kstruct, nid, key_len, iv_len, cbits, \
395 flags, init_key, cleanup, set_asn1, get_asn1, ctrl) \
396 BLOCK_CIPHER_def_ofb(cname, kstruct, nid, key_len, iv_len, cbits, \
397 flags, init_key, cleanup, set_asn1, get_asn1, ctrl) \
398 BLOCK_CIPHER_def_ecb(cname, kstruct, nid, block_size, key_len, flags, \
399 init_key, cleanup, set_asn1, get_asn1, ctrl)
402 #define BLOCK_CIPHER_defs(cname, kstruct, \
403 nid, block_size, key_len, iv_len, flags,\
404 init_key, cleanup, set_asn1, get_asn1, ctrl)\
405 static const EVP_CIPHER cname##_cbc = {\
406 nid##_cbc, block_size, key_len, iv_len, \
407 flags | EVP_CIPH_CBC_MODE,\
411 sizeof(EVP_CIPHER_CTX)-sizeof((((EVP_CIPHER_CTX *)NULL)->c))+\
412 sizeof((((EVP_CIPHER_CTX *)NULL)->c.kstruct)),\
417 const EVP_CIPHER *EVP_##cname##_cbc(void) { return &cname##_cbc; }\
418 static const EVP_CIPHER cname##_cfb = {\
419 nid##_cfb64, 1, key_len, iv_len, \
420 flags | EVP_CIPH_CFB_MODE,\
424 sizeof(EVP_CIPHER_CTX)-sizeof((((EVP_CIPHER_CTX *)NULL)->c))+\
425 sizeof((((EVP_CIPHER_CTX *)NULL)->c.kstruct)),\
430 const EVP_CIPHER *EVP_##cname##_cfb(void) { return &cname##_cfb; }\
431 static const EVP_CIPHER cname##_ofb = {\
432 nid##_ofb64, 1, key_len, iv_len, \
433 flags | EVP_CIPH_OFB_MODE,\
437 sizeof(EVP_CIPHER_CTX)-sizeof((((EVP_CIPHER_CTX *)NULL)->c))+\
438 sizeof((((EVP_CIPHER_CTX *)NULL)->c.kstruct)),\
443 const EVP_CIPHER *EVP_##cname##_ofb(void) { return &cname##_ofb; }\
444 static const EVP_CIPHER cname##_ecb = {\
445 nid##_ecb, block_size, key_len, iv_len, \
446 flags | EVP_CIPH_ECB_MODE,\
450 sizeof(EVP_CIPHER_CTX)-sizeof((((EVP_CIPHER_CTX *)NULL)->c))+\
451 sizeof((((EVP_CIPHER_CTX *)NULL)->c.kstruct)),\
456 const EVP_CIPHER *EVP_##cname##_ecb(void) { return &cname##_ecb; }
459 #define IMPLEMENT_BLOCK_CIPHER(cname, ksched, cprefix, kstruct, nid, \
460 block_size, key_len, iv_len, cbits, \
462 cleanup, set_asn1, get_asn1, ctrl) \
463 BLOCK_CIPHER_all_funcs(cname, cprefix, cbits, kstruct, ksched) \
464 BLOCK_CIPHER_defs(cname, kstruct, nid, block_size, key_len, iv_len, \
465 cbits, flags, init_key, cleanup, set_asn1, \
468 #define IMPLEMENT_CFBR(cipher,cprefix,kstruct,ksched,keysize,cbits,iv_len,fl) \
469 BLOCK_CIPHER_func_cfb(cipher##_##keysize,cprefix,cbits,kstruct,ksched) \
470 BLOCK_CIPHER_def_cfb(cipher##_##keysize,kstruct, \
471 NID_##cipher##_##keysize, keysize/8, iv_len, cbits, \
472 (fl)|EVP_CIPH_FLAG_DEFAULT_ASN1, \
473 cipher##_init_key, NULL, NULL, NULL, NULL)
476 # ifndef OPENSSL_NO_EC
478 #define X25519_KEYLEN 32
479 #define X448_KEYLEN 56
480 #define ED448_KEYLEN 57
482 #define MAX_KEYLEN ED448_KEYLEN
485 unsigned char pubkey[MAX_KEYLEN];
486 unsigned char *privkey;
492 * Type needs to be a bit field Sub-type needs to be for variations on the
493 * method, as in, can it do arbitrary encryption....
498 CRYPTO_REF_COUNT references;
499 const EVP_PKEY_ASN1_METHOD *ameth;
501 ENGINE *pmeth_engine; /* If not NULL public key ENGINE to use */
504 # ifndef OPENSSL_NO_RSA
505 struct rsa_st *rsa; /* RSA */
507 # ifndef OPENSSL_NO_DSA
508 struct dsa_st *dsa; /* DSA */
510 # ifndef OPENSSL_NO_DH
511 struct dh_st *dh; /* DH */
513 # ifndef OPENSSL_NO_EC
514 struct ec_key_st *ec; /* ECC */
515 ECX_KEY *ecx; /* X25519, X448, Ed25519, Ed448 */
519 STACK_OF(X509_ATTRIBUTE) *attributes; /* [ 0 ] */
524 void openssl_add_all_ciphers_int(void);
525 void openssl_add_all_digests_int(void);
526 void openssl_add_all_macs_int(void);
527 void evp_cleanup_int(void);
528 void evp_app_cleanup_int(void);
530 /* Pulling defines out of C source files */
532 #define EVP_RC4_KEY_SIZE 16
533 #ifndef TLS1_1_VERSION
534 # define TLS1_1_VERSION 0x0302
537 void evp_encode_ctx_set_flags(EVP_ENCODE_CTX *ctx, unsigned int flags);
539 /* EVP_ENCODE_CTX flags */
540 /* Don't generate new lines when encoding */
541 #define EVP_ENCODE_CTX_NO_NEWLINES 1
542 /* Use the SRP base64 alphabet instead of the standard one */
543 #define EVP_ENCODE_CTX_USE_SRP_ALPHABET 2