diff options
Diffstat (limited to 'openssl/crypto/rsa/rsa_pk1.c')
| -rw-r--r-- | openssl/crypto/rsa/rsa_pk1.c | 410 |
1 files changed, 208 insertions, 202 deletions
diff --git a/openssl/crypto/rsa/rsa_pk1.c b/openssl/crypto/rsa/rsa_pk1.c index c2da56f6c..efa1fd3e9 100644 --- a/openssl/crypto/rsa/rsa_pk1.c +++ b/openssl/crypto/rsa/rsa_pk1.c @@ -5,21 +5,21 @@ * 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: @@ -34,10 +34,10 @@ * 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 + * 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 @@ -49,7 +49,7 @@ * 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 @@ -65,205 +65,211 @@ #include <openssl/rand.h> int RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen, - const unsigned char *from, int flen) - { - int j; - unsigned char *p; - - if (flen > (tlen-RSA_PKCS1_PADDING_SIZE)) - { - RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); - return(0); - } - - p=(unsigned char *)to; - - *(p++)=0; - *(p++)=1; /* Private Key BT (Block Type) */ - - /* pad out with 0xff data */ - j=tlen-3-flen; - memset(p,0xff,j); - p+=j; - *(p++)='\0'; - memcpy(p,from,(unsigned int)flen); - return(1); - } + const unsigned char *from, int flen) +{ + int j; + unsigned char *p; + + if (flen > (tlen - RSA_PKCS1_PADDING_SIZE)) { + RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_1, + RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); + return (0); + } + + p = (unsigned char *)to; + + *(p++) = 0; + *(p++) = 1; /* Private Key BT (Block Type) */ + + /* pad out with 0xff data */ + j = tlen - 3 - flen; + memset(p, 0xff, j); + p += j; + *(p++) = '\0'; + memcpy(p, from, (unsigned int)flen); + return (1); +} int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen, - const unsigned char *from, int flen, int num) - { - int i,j; - const unsigned char *p; - - p=from; - if ((num != (flen+1)) || (*(p++) != 01)) - { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BLOCK_TYPE_IS_NOT_01); - return(-1); - } - - /* scan over padding data */ - j=flen-1; /* one for type. */ - for (i=0; i<j; i++) - { - if (*p != 0xff) /* should decrypt to 0xff */ - { - if (*p == 0) - { p++; break; } - else { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_FIXED_HEADER_DECRYPT); - return(-1); - } - } - p++; - } - - if (i == j) - { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_NULL_BEFORE_BLOCK_MISSING); - return(-1); - } - - if (i < 8) - { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_PAD_BYTE_COUNT); - return(-1); - } - i++; /* Skip over the '\0' */ - j-=i; - if (j > tlen) - { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE); - return(-1); - } - memcpy(to,p,(unsigned int)j); - - return(j); - } + const unsigned char *from, int flen, + int num) +{ + int i, j; + const unsigned char *p; + + p = from; + if ((num != (flen + 1)) || (*(p++) != 01)) { + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, + RSA_R_BLOCK_TYPE_IS_NOT_01); + return (-1); + } + + /* scan over padding data */ + j = flen - 1; /* one for type. */ + for (i = 0; i < j; i++) { + if (*p != 0xff) { /* should decrypt to 0xff */ + if (*p == 0) { + p++; + break; + } else { + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, + RSA_R_BAD_FIXED_HEADER_DECRYPT); + return (-1); + } + } + p++; + } + + if (i == j) { + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, + RSA_R_NULL_BEFORE_BLOCK_MISSING); + return (-1); + } + + if (i < 8) { + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, + RSA_R_BAD_PAD_BYTE_COUNT); + return (-1); + } + i++; /* Skip over the '\0' */ + j -= i; + if (j > tlen) { + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, RSA_R_DATA_TOO_LARGE); + return (-1); + } + memcpy(to, p, (unsigned int)j); + + return (j); +} int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen, - const unsigned char *from, int flen) - { - int i,j; - unsigned char *p; - - if (flen > (tlen-11)) - { - RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_2,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); - return(0); - } - - p=(unsigned char *)to; - - *(p++)=0; - *(p++)=2; /* Public Key BT (Block Type) */ - - /* pad out with non-zero random data */ - j=tlen-3-flen; - - if (RAND_bytes(p,j) <= 0) - return(0); - for (i=0; i<j; i++) - { - if (*p == '\0') - do { - if (RAND_bytes(p,1) <= 0) - return(0); - } while (*p == '\0'); - p++; - } - - *(p++)='\0'; - - memcpy(p,from,(unsigned int)flen); - return(1); - } + const unsigned char *from, int flen) +{ + int i, j; + unsigned char *p; + + if (flen > (tlen - 11)) { + RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_2, + RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); + return (0); + } + + p = (unsigned char *)to; + + *(p++) = 0; + *(p++) = 2; /* Public Key BT (Block Type) */ + + /* pad out with non-zero random data */ + j = tlen - 3 - flen; + + if (RAND_bytes(p, j) <= 0) + return (0); + for (i = 0; i < j; i++) { + if (*p == '\0') + do { + if (RAND_bytes(p, 1) <= 0) + return (0); + } while (*p == '\0'); + p++; + } + + *(p++) = '\0'; + + memcpy(p, from, (unsigned int)flen); + return (1); +} int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen, - const unsigned char *from, int flen, int num) - { - int i; - /* |em| is the encoded message, zero-padded to exactly |num| bytes */ - unsigned char *em = NULL; - unsigned int good, found_zero_byte; - int zero_index = 0, msg_index, mlen = -1; - - if (tlen < 0 || flen < 0) - return -1; - - /* PKCS#1 v1.5 decryption. See "PKCS #1 v2.2: RSA Cryptography - * Standard", section 7.2.2. */ - - if (flen > num) - goto err; - - if (num < 11) - goto err; - - em = OPENSSL_malloc(num); - if (em == NULL) - { - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, ERR_R_MALLOC_FAILURE); - return -1; - } - memset(em, 0, num); - /* - * Always do this zero-padding copy (even when num == flen) to avoid - * leaking that information. The copy still leaks some side-channel - * information, but it's impossible to have a fixed memory access - * pattern since we can't read out of the bounds of |from|. - * - * TODO(emilia): Consider porting BN_bn2bin_padded from BoringSSL. - */ - memcpy(em + num - flen, from, flen); - - good = constant_time_is_zero(em[0]); - good &= constant_time_eq(em[1], 2); - - found_zero_byte = 0; - for (i = 2; i < num; i++) - { - unsigned int equals0 = constant_time_is_zero(em[i]); - zero_index = constant_time_select_int(~found_zero_byte & equals0, i, zero_index); - found_zero_byte |= equals0; - } - - /* - * PS must be at least 8 bytes long, and it starts two bytes into |em|. - * If we never found a 0-byte, then |zero_index| is 0 and the check - * also fails. - */ - good &= constant_time_ge((unsigned int)(zero_index), 2 + 8); - - /* Skip the zero byte. This is incorrect if we never found a zero-byte - * but in this case we also do not copy the message out. */ - msg_index = zero_index + 1; - mlen = num - msg_index; - - /* For good measure, do this check in constant time as well; it could - * leak something if |tlen| was assuming valid padding. */ - good &= constant_time_ge((unsigned int)(tlen), (unsigned int)(mlen)); - - /* - * We can't continue in constant-time because we need to copy the result - * and we cannot fake its length. This unavoidably leaks timing - * information at the API boundary. - * TODO(emilia): this could be addressed at the call site, - * see BoringSSL commit 0aa0767340baf925bda4804882aab0cb974b2d26. - */ - if (!good) - { - mlen = -1; - goto err; - } - - memcpy(to, em + msg_index, mlen); - -err: - if (em != NULL) - OPENSSL_free(em); - if (mlen == -1) - RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, RSA_R_PKCS_DECODING_ERROR); - return mlen; - } + const unsigned char *from, int flen, + int num) +{ + int i; + /* |em| is the encoded message, zero-padded to exactly |num| bytes */ + unsigned char *em = NULL; + unsigned int good, found_zero_byte; + int zero_index = 0, msg_index, mlen = -1; + + if (tlen < 0 || flen < 0) + return -1; + + /* + * PKCS#1 v1.5 decryption. See "PKCS #1 v2.2: RSA Cryptography Standard", + * section 7.2.2. + */ + + if (flen > num) + goto err; + + if (num < 11) + goto err; + + em = OPENSSL_malloc(num); + if (em == NULL) { + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, ERR_R_MALLOC_FAILURE); + return -1; + } + memset(em, 0, num); + /* + * Always do this zero-padding copy (even when num == flen) to avoid + * leaking that information. The copy still leaks some side-channel + * information, but it's impossible to have a fixed memory access + * pattern since we can't read out of the bounds of |from|. + * + * TODO(emilia): Consider porting BN_bn2bin_padded from BoringSSL. + */ + memcpy(em + num - flen, from, flen); + + good = constant_time_is_zero(em[0]); + good &= constant_time_eq(em[1], 2); + + found_zero_byte = 0; + for (i = 2; i < num; i++) { + unsigned int equals0 = constant_time_is_zero(em[i]); + zero_index = + constant_time_select_int(~found_zero_byte & equals0, i, + zero_index); + found_zero_byte |= equals0; + } + + /* + * PS must be at least 8 bytes long, and it starts two bytes into |em|. + * If we never found a 0-byte, then |zero_index| is 0 and the check + * also fails. + */ + good &= constant_time_ge((unsigned int)(zero_index), 2 + 8); + + /* + * Skip the zero byte. This is incorrect if we never found a zero-byte + * but in this case we also do not copy the message out. + */ + msg_index = zero_index + 1; + mlen = num - msg_index; + + /* + * For good measure, do this check in constant time as well; it could + * leak something if |tlen| was assuming valid padding. + */ + good &= constant_time_ge((unsigned int)(tlen), (unsigned int)(mlen)); + + /* + * We can't continue in constant-time because we need to copy the result + * and we cannot fake its length. This unavoidably leaks timing + * information at the API boundary. + * TODO(emilia): this could be addressed at the call site, + * see BoringSSL commit 0aa0767340baf925bda4804882aab0cb974b2d26. + */ + if (!good) { + mlen = -1; + goto err; + } + + memcpy(to, em + msg_index, mlen); + + err: + if (em != NULL) + OPENSSL_free(em); + if (mlen == -1) + RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, + RSA_R_PKCS_DECODING_ERROR); + return mlen; +} |