/* $OpenBSD: pem_lib.c,v 1.56 2024/02/18 15:44:10 tb Exp $ */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ #include #include #include #include #include #include #include #include #include #include #include #include #ifndef OPENSSL_NO_DES #include #endif #include "asn1_local.h" #include "evp_local.h" #define MIN_LENGTH 4 static int load_iv(char **fromp, unsigned char *to, int num); static int check_pem(const char *nm, const char *name); int pem_check_suffix(const char *pem_str, const char *suffix); /* XXX LSSL ABI XXX return value and `num' ought to be size_t */ int PEM_def_callback(char *buf, int num, int w, void *key) { size_t l; int i; const char *prompt; if (num < 0) return -1; if (key) { l = strlen(key); if (l > (size_t)num) l = (size_t)num; memcpy(buf, key, l); return (int)l; } prompt = EVP_get_pw_prompt(); if (prompt == NULL) prompt = "Enter PEM pass phrase:"; for (;;) { i = EVP_read_pw_string_min(buf, MIN_LENGTH, num, prompt, w); if (i != 0) { PEMerror(PEM_R_PROBLEMS_GETTING_PASSWORD); memset(buf, 0, num); return (-1); } l = strlen(buf); if (l < MIN_LENGTH) { fprintf(stderr, "phrase is too short, " "needs to be at least %zu chars\n", (size_t)MIN_LENGTH); } else break; } return (int)l; } LCRYPTO_ALIAS(PEM_def_callback); void PEM_proc_type(char *buf, int type) { const char *str; if (type == PEM_TYPE_ENCRYPTED) str = "ENCRYPTED"; else if (type == PEM_TYPE_MIC_CLEAR) str = "MIC-CLEAR"; else if (type == PEM_TYPE_MIC_ONLY) str = "MIC-ONLY"; else str = "BAD-TYPE"; strlcat(buf, "Proc-Type: 4,", PEM_BUFSIZE); strlcat(buf, str, PEM_BUFSIZE); strlcat(buf, "\n", PEM_BUFSIZE); } LCRYPTO_ALIAS(PEM_proc_type); void PEM_dek_info(char *buf, const char *type, int len, char *str) { static const unsigned char map[17] = "0123456789ABCDEF"; long i; int j; strlcat(buf, "DEK-Info: ", PEM_BUFSIZE); strlcat(buf, type, PEM_BUFSIZE); strlcat(buf, ",", PEM_BUFSIZE); j = strlen(buf); if (j + (len * 2) + 1 > PEM_BUFSIZE) return; for (i = 0; i < len; i++) { buf[j + i * 2] = map[(str[i] >> 4) & 0x0f]; buf[j + i * 2 + 1] = map[(str[i]) & 0x0f]; } buf[j + i * 2] = '\n'; buf[j + i * 2 + 1] = '\0'; } LCRYPTO_ALIAS(PEM_dek_info); void * PEM_ASN1_read(d2i_of_void *d2i, const char *name, FILE *fp, void **x, pem_password_cb *cb, void *u) { BIO *b; void *ret; if ((b = BIO_new(BIO_s_file())) == NULL) { PEMerror(ERR_R_BUF_LIB); return (0); } BIO_set_fp(b, fp, BIO_NOCLOSE); ret = PEM_ASN1_read_bio(d2i, name, b, x, cb, u); BIO_free(b); return (ret); } LCRYPTO_ALIAS(PEM_ASN1_read); static int check_pem(const char *nm, const char *name) { /* Normal matching nm and name */ if (!strcmp(nm, name)) return 1; /* Make PEM_STRING_EVP_PKEY match any private key */ if (!strcmp(name, PEM_STRING_EVP_PKEY)) { int slen; const EVP_PKEY_ASN1_METHOD *ameth; if (!strcmp(nm, PEM_STRING_PKCS8)) return 1; if (!strcmp(nm, PEM_STRING_PKCS8INF)) return 1; slen = pem_check_suffix(nm, "PRIVATE KEY"); if (slen > 0) { /* NB: ENGINE implementations wont contain * a deprecated old private key decode function * so don't look for them. */ ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen); if (ameth && ameth->old_priv_decode) return 1; } return 0; } if (!strcmp(name, PEM_STRING_PARAMETERS)) { int slen; const EVP_PKEY_ASN1_METHOD *ameth; slen = pem_check_suffix(nm, "PARAMETERS"); if (slen > 0) { ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen); if (ameth) { int r; if (ameth->param_decode) r = 1; else r = 0; return r; } } return 0; } /* Permit older strings */ if (!strcmp(nm, PEM_STRING_X509_OLD) && !strcmp(name, PEM_STRING_X509)) return 1; if (!strcmp(nm, PEM_STRING_X509_REQ_OLD) && !strcmp(name, PEM_STRING_X509_REQ)) return 1; /* Allow normal certs to be read as trusted certs */ if (!strcmp(nm, PEM_STRING_X509) && !strcmp(name, PEM_STRING_X509_TRUSTED)) return 1; if (!strcmp(nm, PEM_STRING_X509_OLD) && !strcmp(name, PEM_STRING_X509_TRUSTED)) return 1; /* Some CAs use PKCS#7 with CERTIFICATE headers */ if (!strcmp(nm, PEM_STRING_X509) && !strcmp(name, PEM_STRING_PKCS7)) return 1; if (!strcmp(nm, PEM_STRING_PKCS7_SIGNED) && !strcmp(name, PEM_STRING_PKCS7)) return 1; #ifndef OPENSSL_NO_CMS if (strcmp(nm, PEM_STRING_X509) == 0 && strcmp(name, PEM_STRING_CMS) == 0) return 1; /* Allow CMS to be read from PKCS#7 headers */ if (strcmp(nm, PEM_STRING_PKCS7) == 0 && strcmp(name, PEM_STRING_CMS) == 0) return 1; #endif return 0; } int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm, const char *name, BIO *bp, pem_password_cb *cb, void *u) { EVP_CIPHER_INFO cipher; char *nm = NULL, *header = NULL; unsigned char *data = NULL; long len; int ret = 0; for (;;) { if (!PEM_read_bio(bp, &nm, &header, &data, &len)) { if (ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE) ERR_asprintf_error_data("Expecting: %s", name); return 0; } if (check_pem(nm, name)) break; free(nm); free(header); free(data); } if (!PEM_get_EVP_CIPHER_INFO(header, &cipher)) goto err; if (!PEM_do_header(&cipher, data, &len, cb, u)) goto err; *pdata = data; *plen = len; if (pnm) *pnm = nm; ret = 1; err: if (!ret || !pnm) free(nm); free(header); if (!ret) free(data); return ret; } LCRYPTO_ALIAS(PEM_bytes_read_bio); int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp, void *x, const EVP_CIPHER *enc, unsigned char *kstr, int klen, pem_password_cb *callback, void *u) { BIO *b; int ret; if ((b = BIO_new(BIO_s_file())) == NULL) { PEMerror(ERR_R_BUF_LIB); return (0); } BIO_set_fp(b, fp, BIO_NOCLOSE); ret = PEM_ASN1_write_bio(i2d, name, b, x, enc, kstr, klen, callback, u); BIO_free(b); return (ret); } LCRYPTO_ALIAS(PEM_ASN1_write); int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp, void *x, const EVP_CIPHER *enc, unsigned char *kstr, int klen, pem_password_cb *callback, void *u) { EVP_CIPHER_CTX ctx; int dsize = 0, i, j, ret = 0; unsigned char *p, *data = NULL; const char *objstr = NULL; char buf[PEM_BUFSIZE]; unsigned char key[EVP_MAX_KEY_LENGTH]; unsigned char iv[EVP_MAX_IV_LENGTH]; if (enc != NULL) { objstr = OBJ_nid2sn(EVP_CIPHER_nid(enc)); if (objstr == NULL) { PEMerror(PEM_R_UNSUPPORTED_CIPHER); goto err; } } if ((dsize = i2d(x, NULL)) < 0) { PEMerror(ERR_R_ASN1_LIB); dsize = 0; goto err; } /* dzise + 8 bytes are needed */ /* actually it needs the cipher block size extra... */ data = malloc(dsize + 20); if (data == NULL) { PEMerror(ERR_R_MALLOC_FAILURE); goto err; } p = data; i = i2d(x, &p); if (enc != NULL) { if (kstr == NULL) { if (callback == NULL) klen = PEM_def_callback(buf, PEM_BUFSIZE, 1, u); else klen = (*callback)(buf, PEM_BUFSIZE, 1, u); if (klen <= 0) { PEMerror(PEM_R_READ_KEY); goto err; } kstr = (unsigned char *)buf; } if ((size_t)enc->iv_len > sizeof(iv)) { PEMerror(EVP_R_IV_TOO_LARGE); goto err; } arc4random_buf(iv, enc->iv_len); /* Generate a salt */ /* The 'iv' is used as the iv and as a salt. It is * NOT taken from the BytesToKey function */ if (!EVP_BytesToKey(enc, EVP_md5(), iv, kstr, klen, 1, key, NULL)) goto err; if (kstr == (unsigned char *)buf) explicit_bzero(buf, PEM_BUFSIZE); if (strlen(objstr) + 23 + 2 * enc->iv_len + 13 > sizeof buf) { PEMerror(ASN1_R_BUFFER_TOO_SMALL); goto err; } buf[0] = '\0'; PEM_proc_type(buf, PEM_TYPE_ENCRYPTED); PEM_dek_info(buf, objstr, enc->iv_len, (char *)iv); /* k=strlen(buf); */ EVP_CIPHER_CTX_legacy_clear(&ctx); ret = 1; if (!EVP_EncryptInit_ex(&ctx, enc, NULL, key, iv) || !EVP_EncryptUpdate(&ctx, data, &j, data, i) || !EVP_EncryptFinal_ex(&ctx, &(data[j]), &i)) ret = 0; EVP_CIPHER_CTX_cleanup(&ctx); if (ret == 0) goto err; i += j; } else { ret = 1; buf[0] = '\0'; } i = PEM_write_bio(bp, name, buf, data, i); if (i <= 0) ret = 0; err: explicit_bzero(key, sizeof(key)); explicit_bzero(iv, sizeof(iv)); explicit_bzero((char *)&ctx, sizeof(ctx)); explicit_bzero(buf, PEM_BUFSIZE); freezero(data, (unsigned int)dsize); return (ret); } LCRYPTO_ALIAS(PEM_ASN1_write_bio); int PEM_do_header(EVP_CIPHER_INFO *cipher, unsigned char *data, long *plen, pem_password_cb *callback, void *u) { int i, j, o, klen; long len; EVP_CIPHER_CTX ctx; unsigned char key[EVP_MAX_KEY_LENGTH]; char buf[PEM_BUFSIZE]; len = *plen; if (cipher->cipher == NULL) return (1); if (callback == NULL) klen = PEM_def_callback(buf, PEM_BUFSIZE, 0, u); else klen = callback(buf, PEM_BUFSIZE, 0, u); if (klen <= 0) { PEMerror(PEM_R_BAD_PASSWORD_READ); return (0); } if (!EVP_BytesToKey(cipher->cipher, EVP_md5(), &(cipher->iv[0]), (unsigned char *)buf, klen, 1, key, NULL)) return 0; j = (int)len; EVP_CIPHER_CTX_legacy_clear(&ctx); o = EVP_DecryptInit_ex(&ctx, cipher->cipher, NULL, key, &(cipher->iv[0])); if (o) o = EVP_DecryptUpdate(&ctx, data, &i, data, j); if (o) o = EVP_DecryptFinal_ex(&ctx, &(data[i]), &j); EVP_CIPHER_CTX_cleanup(&ctx); explicit_bzero((char *)buf, sizeof(buf)); explicit_bzero((char *)key, sizeof(key)); if (!o) { PEMerror(PEM_R_BAD_DECRYPT); return (0); } *plen = j + i; return (1); } LCRYPTO_ALIAS(PEM_do_header); int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cipher) { const EVP_CIPHER *enc = NULL; char *p, c; char **header_pp = &header; cipher->cipher = NULL; if ((header == NULL) || (*header == '\0') || (*header == '\n')) return (1); if (strncmp(header, "Proc-Type: ", 11) != 0) { PEMerror(PEM_R_NOT_PROC_TYPE); return (0); } header += 11; if (*header != '4') return (0); header++; if (*header != ',') return (0); header++; if (strncmp(header, "ENCRYPTED", 9) != 0) { PEMerror(PEM_R_NOT_ENCRYPTED); return (0); } for (; (*header != '\n') && (*header != '\0'); header++) ; if (*header == '\0') { PEMerror(PEM_R_SHORT_HEADER); return (0); } header++; if (strncmp(header, "DEK-Info: ", 10) != 0) { PEMerror(PEM_R_NOT_DEK_INFO); return (0); } header += 10; p = header; for (;;) { c= *header; if (!( ((c >= 'A') && (c <= 'Z')) || (c == '-') || ((c >= '0') && (c <= '9')))) break; header++; } *header = '\0'; cipher->cipher = enc = EVP_get_cipherbyname(p); *header = c; header++; if (enc == NULL) { PEMerror(PEM_R_UNSUPPORTED_ENCRYPTION); return (0); } if (!load_iv(header_pp, &(cipher->iv[0]), enc->iv_len)) return (0); return (1); } LCRYPTO_ALIAS(PEM_get_EVP_CIPHER_INFO); static int load_iv(char **fromp, unsigned char *to, int num) { int v, i; char *from; from= *fromp; for (i = 0; i < num; i++) to[i] = 0; num *= 2; for (i = 0; i < num; i++) { if ((*from >= '0') && (*from <= '9')) v = *from - '0'; else if ((*from >= 'A') && (*from <= 'F')) v = *from - 'A' + 10; else if ((*from >= 'a') && (*from <= 'f')) v = *from - 'a' + 10; else { PEMerror(PEM_R_BAD_IV_CHARS); return (0); } from++; to[i / 2] |= v << (long)((!(i & 1)) * 4); } *fromp = from; return (1); } int PEM_write(FILE *fp, const char *name, const char *header, const unsigned char *data, long len) { BIO *b; int ret; if ((b = BIO_new(BIO_s_file())) == NULL) { PEMerror(ERR_R_BUF_LIB); return (0); } BIO_set_fp(b, fp, BIO_NOCLOSE); ret = PEM_write_bio(b, name, header, data, len); BIO_free(b); return (ret); } LCRYPTO_ALIAS(PEM_write); int PEM_write_bio(BIO *bp, const char *name, const char *header, const unsigned char *data, long len) { int nlen, n, i, j, outl; unsigned char *buf = NULL; EVP_ENCODE_CTX ctx; int reason = ERR_R_BUF_LIB; EVP_EncodeInit(&ctx); nlen = strlen(name); if ((BIO_write(bp, "-----BEGIN ", 11) != 11) || (BIO_write(bp, name, nlen) != nlen) || (BIO_write(bp, "-----\n", 6) != 6)) goto err; if (header != NULL && (i = strlen(header)) > 0) { if ((BIO_write(bp, header, i) != i) || (BIO_write(bp, "\n", 1) != 1)) goto err; } buf = reallocarray(NULL, PEM_BUFSIZE, 8); if (buf == NULL) { reason = ERR_R_MALLOC_FAILURE; goto err; } i = j = 0; while (len > 0) { n = (int)((len > (PEM_BUFSIZE * 5)) ? (PEM_BUFSIZE * 5) : len); if (!EVP_EncodeUpdate(&ctx, buf, &outl, &(data[j]), n)) goto err; if ((outl) && (BIO_write(bp, (char *)buf, outl) != outl)) goto err; i += outl; len -= n; j += n; } EVP_EncodeFinal(&ctx, buf, &outl); if ((outl > 0) && (BIO_write(bp, (char *)buf, outl) != outl)) goto err; freezero(buf, PEM_BUFSIZE * 8); buf = NULL; if ((BIO_write(bp, "-----END ", 9) != 9) || (BIO_write(bp, name, nlen) != nlen) || (BIO_write(bp, "-----\n", 6) != 6)) goto err; return (i + outl); err: freezero(buf, PEM_BUFSIZE * 8); PEMerror(reason); return (0); } LCRYPTO_ALIAS(PEM_write_bio); int PEM_read(FILE *fp, char **name, char **header, unsigned char **data, long *len) { BIO *b; int ret; if ((b = BIO_new(BIO_s_file())) == NULL) { PEMerror(ERR_R_BUF_LIB); return (0); } BIO_set_fp(b, fp, BIO_NOCLOSE); ret = PEM_read_bio(b, name, header, data, len); BIO_free(b); return (ret); } LCRYPTO_ALIAS(PEM_read); int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data, long *len) { EVP_ENCODE_CTX ctx; int end = 0, i, k, bl = 0, hl = 0, nohead = 0; char buf[256]; BUF_MEM *nameB; BUF_MEM *headerB; BUF_MEM *dataB, *tmpB; nameB = BUF_MEM_new(); headerB = BUF_MEM_new(); dataB = BUF_MEM_new(); if ((nameB == NULL) || (headerB == NULL) || (dataB == NULL)) { BUF_MEM_free(nameB); BUF_MEM_free(headerB); BUF_MEM_free(dataB); PEMerror(ERR_R_MALLOC_FAILURE); return (0); } buf[254] = '\0'; for (;;) { i = BIO_gets(bp, buf, 254); if (i <= 0) { PEMerror(PEM_R_NO_START_LINE); goto err; } while ((i >= 0) && (buf[i] <= ' ')) i--; buf[++i] = '\n'; buf[++i] = '\0'; if (strncmp(buf, "-----BEGIN ", 11) == 0) { i = strlen(&(buf[11])); if (strncmp(&(buf[11 + i - 6]), "-----\n", 6) != 0) continue; if (!BUF_MEM_grow(nameB, i + 9)) { PEMerror(ERR_R_MALLOC_FAILURE); goto err; } memcpy(nameB->data, &(buf[11]), i - 6); nameB->data[i - 6] = '\0'; break; } } hl = 0; if (!BUF_MEM_grow(headerB, 256)) { PEMerror(ERR_R_MALLOC_FAILURE); goto err; } headerB->data[0] = '\0'; for (;;) { i = BIO_gets(bp, buf, 254); if (i <= 0) break; while ((i >= 0) && (buf[i] <= ' ')) i--; buf[++i] = '\n'; buf[++i] = '\0'; if (buf[0] == '\n') break; if (!BUF_MEM_grow(headerB, hl + i + 9)) { PEMerror(ERR_R_MALLOC_FAILURE); goto err; } if (strncmp(buf, "-----END ", 9) == 0) { nohead = 1; break; } memcpy(&(headerB->data[hl]), buf, i); headerB->data[hl + i] = '\0'; hl += i; } bl = 0; if (!BUF_MEM_grow(dataB, 1024)) { PEMerror(ERR_R_MALLOC_FAILURE); goto err; } dataB->data[0] = '\0'; if (!nohead) { for (;;) { i = BIO_gets(bp, buf, 254); if (i <= 0) break; while ((i >= 0) && (buf[i] <= ' ')) i--; buf[++i] = '\n'; buf[++i] = '\0'; if (i != 65) end = 1; if (strncmp(buf, "-----END ", 9) == 0) break; if (i > 65) break; if (!BUF_MEM_grow_clean(dataB, i + bl + 9)) { PEMerror(ERR_R_MALLOC_FAILURE); goto err; } memcpy(&(dataB->data[bl]), buf, i); dataB->data[bl + i] = '\0'; bl += i; if (end) { buf[0] = '\0'; i = BIO_gets(bp, buf, 254); if (i <= 0) break; while ((i >= 0) && (buf[i] <= ' ')) i--; buf[++i] = '\n'; buf[++i] = '\0'; break; } } } else { tmpB = headerB; headerB = dataB; dataB = tmpB; bl = hl; } i = strlen(nameB->data); if ((strncmp(buf, "-----END ", 9) != 0) || (strncmp(nameB->data, &(buf[9]), i) != 0) || (strncmp(&(buf[9 + i]), "-----\n", 6) != 0)) { PEMerror(PEM_R_BAD_END_LINE); goto err; } EVP_DecodeInit(&ctx); i = EVP_DecodeUpdate(&ctx, (unsigned char *)dataB->data, &bl, (unsigned char *)dataB->data, bl); if (i < 0) { PEMerror(PEM_R_BAD_BASE64_DECODE); goto err; } i = EVP_DecodeFinal(&ctx, (unsigned char *)&(dataB->data[bl]), &k); if (i < 0) { PEMerror(PEM_R_BAD_BASE64_DECODE); goto err; } bl += k; if (bl == 0) goto err; *name = nameB->data; *header = headerB->data; *data = (unsigned char *)dataB->data; *len = bl; free(nameB); free(headerB); free(dataB); return (1); err: BUF_MEM_free(nameB); BUF_MEM_free(headerB); BUF_MEM_free(dataB); return (0); } LCRYPTO_ALIAS(PEM_read_bio); /* Check pem string and return prefix length. * If for example the pem_str == "RSA PRIVATE KEY" and suffix = "PRIVATE KEY" * the return value is 3 for the string "RSA". */ int pem_check_suffix(const char *pem_str, const char *suffix) { int pem_len = strlen(pem_str); int suffix_len = strlen(suffix); const char *p; if (suffix_len + 1 >= pem_len) return 0; p = pem_str + pem_len - suffix_len; if (strcmp(p, suffix)) return 0; p--; if (*p != ' ') return 0; return p - pem_str; }